Merge tag 'tty-6.5-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty
authorLinus Torvalds <torvalds@linux-foundation.org>
Mon, 3 Jul 2023 20:14:58 +0000 (13:14 -0700)
committerLinus Torvalds <torvalds@linux-foundation.org>
Mon, 3 Jul 2023 20:14:58 +0000 (13:14 -0700)
Pull tty/serial driver updates from Greg KH:
 "Here is the big set of tty/serial driver updates for 6.5-rc1.

  Included in here are:

   - tty_audit code cleanups from Jiri

   - more 8250 cleanups from Ilpo

   - samsung_tty driver bugfixes

   - 8250 lock port updates

   - usual fsl_lpuart driver updates and fixes

   - other small serial driver fixes and updates, full details in the
     shortlog

  All of these have been in linux-next for a while with no reported
  issues"

* tag 'tty-6.5-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty: (58 commits)
  tty_audit: make data of tty_audit_log() const
  tty_audit: make tty pointers in exposed functions const
  tty_audit: make icanon a bool
  tty_audit: invert the condition in tty_audit_log()
  tty_audit: use kzalloc() in tty_audit_buf_alloc()
  tty_audit: use TASK_COMM_LEN for task comm
  Revert "8250: add support for ASIX devices with a FIFO bug"
  serial: atmel: don't enable IRQs prematurely
  tty: serial: Add Nuvoton ma35d1 serial driver support
  tty: serial: fsl_lpuart: add earlycon for imx8ulp platform
  tty: serial: imx: fix rs485 rx after tx
  selftests: tty: add selftest for tty timestamp updates
  tty: tty_io: update timestamps on all device nodes
  tty: fix hang on tty device with no_room set
  serial: core: fix -EPROBE_DEFER handling in init
  serial: 8250_omap: Use force_suspend and resume for system suspend
  tty: serial: samsung_tty: Use abs() to simplify some code
  tty: serial: samsung_tty: Fix a memory leak in s3c24xx_serial_getclk() when iterating clk
  tty: serial: samsung_tty: Fix a memory leak in s3c24xx_serial_getclk() in case of error
  serial: 8250: Apply FSL workarounds also without SERIAL_8250_CONSOLE
  ...

52 files changed:
arch/mips/alchemy/common/platform.c
arch/powerpc/kernel/legacy_serial.c
drivers/tty/n_tty.c
drivers/tty/serial/8250/8250.h
drivers/tty/serial/8250/8250_aspeed_vuart.c
drivers/tty/serial/8250/8250_bcm7271.c
drivers/tty/serial/8250/8250_core.c
drivers/tty/serial/8250/8250_early.c
drivers/tty/serial/8250/8250_em.c
drivers/tty/serial/8250/8250_exar.c
drivers/tty/serial/8250/8250_fsl.c
drivers/tty/serial/8250/8250_mtk.c
drivers/tty/serial/8250/8250_of.c
drivers/tty/serial/8250/8250_omap.c
drivers/tty/serial/8250/8250_pci.c
drivers/tty/serial/8250/8250_port.c
drivers/tty/serial/8250/8250_pxa.c
drivers/tty/serial/8250/8250_rt288x.c [new file with mode: 0644]
drivers/tty/serial/8250/8250_uniphier.c
drivers/tty/serial/8250/Kconfig
drivers/tty/serial/8250/Makefile
drivers/tty/serial/Kconfig
drivers/tty/serial/Makefile
drivers/tty/serial/amba-pl011.c
drivers/tty/serial/atmel_serial.c
drivers/tty/serial/clps711x.c
drivers/tty/serial/cpm_uart/cpm_uart_core.c
drivers/tty/serial/fsl_lpuart.c
drivers/tty/serial/imx.c
drivers/tty/serial/lantiq.c
drivers/tty/serial/ma35d1_serial.c [new file with mode: 0644]
drivers/tty/serial/max310x.c
drivers/tty/serial/samsung_tty.c
drivers/tty/serial/sc16is7xx.c
drivers/tty/serial/serial_base.h [new file with mode: 0644]
drivers/tty/serial/serial_base_bus.c [new file with mode: 0644]
drivers/tty/serial/serial_core.c
drivers/tty/serial/serial_ctrl.c [new file with mode: 0644]
drivers/tty/serial/serial_port.c [new file with mode: 0644]
drivers/tty/serial/st-asc.c
drivers/tty/serial/stm32-usart.c
drivers/tty/serial/uartlite.c
drivers/tty/serial/xilinx_uartps.c
drivers/tty/tty.h
drivers/tty/tty_audit.c
drivers/tty/tty_io.c
include/linux/serial_8250.h
include/linux/serial_core.h
tools/testing/selftests/Makefile
tools/testing/selftests/tty/.gitignore [new file with mode: 0644]
tools/testing/selftests/tty/Makefile [new file with mode: 0644]
tools/testing/selftests/tty/tty_tstamp_update.c [new file with mode: 0644]

index b8f3397..d4ab34b 100644 (file)
@@ -51,9 +51,9 @@ static void alchemy_8250_pm(struct uart_port *port, unsigned int state,
 #define PORT(_base, _irq)                                      \
        {                                                       \
                .mapbase        = _base,                        \
+               .mapsize        = 0x1000,                       \
                .irq            = _irq,                         \
                .regshift       = 2,                            \
-               .iotype         = UPIO_AU,                      \
                .flags          = UPF_SKIP_TEST | UPF_IOREMAP | \
                                  UPF_FIXED_TYPE,               \
                .type           = PORT_16550A,                  \
@@ -124,8 +124,14 @@ static void __init alchemy_setup_uarts(int ctype)
        au1xx0_uart_device.dev.platform_data = ports;
 
        /* Fill up uartclk. */
-       for (s = 0; s < c; s++)
+       for (s = 0; s < c; s++) {
                ports[s].uartclk = uartclk;
+               if (au_platform_setup(&ports[s]) < 0) {
+                       kfree(ports);
+                       printk(KERN_INFO "Alchemy: missing support for UARTs\n");
+                       return;
+               }
+       }
        if (platform_device_register(&au1xx0_uart_device))
                printk(KERN_INFO "Alchemy: failed to register UARTs\n");
 }
index c9ad124..6ee6574 100644 (file)
@@ -508,12 +508,16 @@ static void __init fixup_port_irq(int index,
 
        port->irq = virq;
 
-#ifdef CONFIG_SERIAL_8250_FSL
-       if (of_device_is_compatible(np, "fsl,ns16550")) {
-               port->handle_irq = fsl8250_handle_irq;
-               port->has_sysrq = IS_ENABLED(CONFIG_SERIAL_8250_CONSOLE);
+       if (IS_ENABLED(CONFIG_SERIAL_8250) &&
+           of_device_is_compatible(np, "fsl,ns16550")) {
+               if (IS_REACHABLE(CONFIG_SERIAL_8250_FSL)) {
+                       port->handle_irq = fsl8250_handle_irq;
+                       port->has_sysrq = IS_ENABLED(CONFIG_SERIAL_8250_CONSOLE);
+               } else {
+                       pr_warn_once("Not activating Freescale specific workaround for device %pOFP\n",
+                                    np);
+               }
        }
-#endif
 }
 
 static void __init fixup_port_pio(int index,
index 1c9e5d2..552e8a7 100644 (file)
@@ -203,8 +203,8 @@ static void n_tty_kick_worker(struct tty_struct *tty)
        struct n_tty_data *ldata = tty->disc_data;
 
        /* Did the input worker stop? Restart it */
-       if (unlikely(ldata->no_room)) {
-               ldata->no_room = 0;
+       if (unlikely(READ_ONCE(ldata->no_room))) {
+               WRITE_ONCE(ldata->no_room, 0);
 
                WARN_RATELIMIT(tty->port->itty == NULL,
                                "scheduling with invalid itty\n");
@@ -1697,7 +1697,7 @@ n_tty_receive_buf_common(struct tty_struct *tty, const unsigned char *cp,
                        if (overflow && room < 0)
                                ldata->read_head--;
                        room = overflow;
-                       ldata->no_room = flow && !room;
+                       WRITE_ONCE(ldata->no_room, flow && !room);
                } else
                        overflow = 0;
 
@@ -1728,6 +1728,17 @@ n_tty_receive_buf_common(struct tty_struct *tty, const unsigned char *cp,
        } else
                n_tty_check_throttle(tty);
 
+       if (unlikely(ldata->no_room)) {
+               /*
+                * Barrier here is to ensure to read the latest read_tail in
+                * chars_in_buffer() and to make sure that read_tail is not loaded
+                * before ldata->no_room is set.
+                */
+               smp_mb();
+               if (!chars_in_buffer(tty))
+                       n_tty_kick_worker(tty);
+       }
+
        up_read(&tty->termios_rwsem);
 
        return rcvd;
@@ -2281,8 +2292,14 @@ more_to_be_read:
                if (time)
                        timeout = time;
        }
-       if (old_tail != ldata->read_tail)
+       if (old_tail != ldata->read_tail) {
+               /*
+                * Make sure no_room is not read in n_tty_kick_worker()
+                * before setting ldata->read_tail in copy_from_read_buf().
+                */
+               smp_mb();
                n_tty_kick_worker(tty);
+       }
        up_read(&tty->termios_rwsem);
 
        remove_wait_queue(&tty->read_wait, &wait);
index 1e8fe44..1aa3e55 100644 (file)
@@ -91,7 +91,6 @@ struct serial8250_config {
 #define UART_BUG_TXEN  BIT(1)  /* UART has buggy TX IIR status */
 #define UART_BUG_NOMSR BIT(2)  /* UART has buggy MSR status bits (Au1x00) */
 #define UART_BUG_THRE  BIT(3)  /* UART has buggy THRE reassertion */
-#define UART_BUG_PARITY        BIT(4)  /* UART mishandles parity if FIFO enabled */
 #define UART_BUG_TXRACE        BIT(5)  /* UART Tx fails to set remote DR */
 
 
@@ -167,18 +166,21 @@ static unsigned int __maybe_unused serial_icr_read(struct uart_8250_port *up,
 
 void serial8250_clear_and_reinit_fifos(struct uart_8250_port *p);
 
-static inline int serial_dl_read(struct uart_8250_port *up)
+static inline u32 serial_dl_read(struct uart_8250_port *up)
 {
        return up->dl_read(up);
 }
 
-static inline void serial_dl_write(struct uart_8250_port *up, int value)
+static inline void serial_dl_write(struct uart_8250_port *up, u32 value)
 {
        up->dl_write(up, value);
 }
 
 static inline bool serial8250_set_THRI(struct uart_8250_port *up)
 {
+       /* Port locked to synchronize UART_IER access against the console. */
+       lockdep_assert_held_once(&up->port.lock);
+
        if (up->ier & UART_IER_THRI)
                return false;
        up->ier |= UART_IER_THRI;
@@ -188,6 +190,9 @@ static inline bool serial8250_set_THRI(struct uart_8250_port *up)
 
 static inline bool serial8250_clear_THRI(struct uart_8250_port *up)
 {
+       /* Port locked to synchronize UART_IER access against the console. */
+       lockdep_assert_held_once(&up->port.lock);
+
        if (!(up->ier & UART_IER_THRI))
                return false;
        up->ier &= ~UART_IER_THRI;
index 9d2a785..4a9e71b 100644 (file)
@@ -275,6 +275,9 @@ static void __aspeed_vuart_set_throttle(struct uart_8250_port *up,
 {
        unsigned char irqs = UART_IER_RLSI | UART_IER_RDI;
 
+       /* Port locked to synchronize UART_IER access against the console. */
+       lockdep_assert_held_once(&up->port.lock);
+
        up->ier &= ~irqs;
        if (!throttle)
                up->ier |= irqs;
index af0e1c0..d4b05d7 100644 (file)
@@ -605,9 +605,13 @@ static int brcmuart_startup(struct uart_port *port)
        /*
         * Disable the Receive Data Interrupt because the DMA engine
         * will handle this.
+        *
+        * Synchronize UART_IER access against the console.
         */
+       spin_lock_irq(&port->lock);
        up->ier &= ~UART_IER_RDI;
        serial_port_out(port, UART_IER, up->ier);
+       spin_unlock_irq(&port->lock);
 
        priv->tx_running = false;
        priv->dma.rx_dma = NULL;
index 13bf535..914e0e6 100644 (file)
@@ -488,6 +488,34 @@ static inline void serial8250_apply_quirks(struct uart_8250_port *up)
        up->port.quirks |= skip_txen_test ? UPQ_NO_TXEN_TEST : 0;
 }
 
+static struct uart_8250_port *serial8250_setup_port(int index)
+{
+       struct uart_8250_port *up;
+
+       if (index >= UART_NR)
+               return NULL;
+
+       up = &serial8250_ports[index];
+       up->port.line = index;
+
+       serial8250_init_port(up);
+       if (!base_ops)
+               base_ops = up->port.ops;
+       up->port.ops = &univ8250_port_ops;
+
+       timer_setup(&up->timer, serial8250_timeout, 0);
+
+       up->ops = &univ8250_driver_ops;
+
+       if (IS_ENABLED(CONFIG_ALPHA_JENSEN) ||
+           (IS_ENABLED(CONFIG_ALPHA_GENERIC) && alpha_jensen()))
+               up->port.set_mctrl = alpha_jensen_set_mctrl;
+
+       serial8250_set_defaults(up);
+
+       return up;
+}
+
 static void __init serial8250_isa_init_ports(void)
 {
        struct uart_8250_port *up;
@@ -501,26 +529,13 @@ static void __init serial8250_isa_init_ports(void)
        if (nr_uarts > UART_NR)
                nr_uarts = UART_NR;
 
-       for (i = 0; i < nr_uarts; i++) {
-               struct uart_8250_port *up = &serial8250_ports[i];
-               struct uart_port *port = &up->port;
-
-               port->line = i;
-               serial8250_init_port(up);
-               if (!base_ops)
-                       base_ops = port->ops;
-               port->ops = &univ8250_port_ops;
-
-               timer_setup(&up->timer, serial8250_timeout, 0);
-
-               up->ops = &univ8250_driver_ops;
-
-               if (IS_ENABLED(CONFIG_ALPHA_JENSEN) ||
-                   (IS_ENABLED(CONFIG_ALPHA_GENERIC) && alpha_jensen()))
-                       port->set_mctrl = alpha_jensen_set_mctrl;
-
-               serial8250_set_defaults(up);
-       }
+       /*
+        * Set up initial isa ports based on nr_uart module param, or else
+        * default to CONFIG_SERIAL_8250_RUNTIME_UARTS. Note that we do not
+        * need to increase nr_uarts when setting up the initial isa ports.
+        */
+       for (i = 0; i < nr_uarts; i++)
+               serial8250_setup_port(i);
 
        /* chain base port ops to support Remote Supervisor Adapter */
        univ8250_port_ops = *base_ops;
@@ -586,16 +601,29 @@ static void univ8250_console_write(struct console *co, const char *s,
 
 static int univ8250_console_setup(struct console *co, char *options)
 {
+       struct uart_8250_port *up;
        struct uart_port *port;
-       int retval;
+       int retval, i;
 
        /*
         * Check whether an invalid uart number has been specified, and
         * if so, search for the first available port that does have
         * console support.
         */
-       if (co->index >= nr_uarts)
+       if (co->index >= UART_NR)
                co->index = 0;
+
+       /*
+        * If the console is past the initial isa ports, init more ports up to
+        * co->index as needed and increment nr_uarts accordingly.
+        */
+       for (i = nr_uarts; i <= co->index; i++) {
+               up = serial8250_setup_port(i);
+               if (!up)
+                       return -ENODEV;
+               nr_uarts++;
+       }
+
        port = &serial8250_ports[co->index].port;
        /* link port to console */
        port->cons = co;
@@ -822,12 +850,16 @@ static int serial8250_probe(struct platform_device *dev)
                uart.port.iotype        = p->iotype;
                uart.port.flags         = p->flags;
                uart.port.mapbase       = p->mapbase;
+               uart.port.mapsize       = p->mapsize;
                uart.port.hub6          = p->hub6;
                uart.port.has_sysrq     = p->has_sysrq;
                uart.port.private_data  = p->private_data;
                uart.port.type          = p->type;
+               uart.bugs               = p->bugs;
                uart.port.serial_in     = p->serial_in;
                uart.port.serial_out    = p->serial_out;
+               uart.dl_read            = p->dl_read;
+               uart.dl_write           = p->dl_write;
                uart.port.handle_irq    = p->handle_irq;
                uart.port.handle_break  = p->handle_break;
                uart.port.set_termios   = p->set_termios;
@@ -990,12 +1022,24 @@ int serial8250_register_8250_port(const struct uart_8250_port *up)
        mutex_lock(&serial_mutex);
 
        uart = serial8250_find_match_or_unused(&up->port);
-       if (uart && uart->port.type != PORT_8250_CIR) {
+       if (!uart) {
+               /*
+                * If the port is past the initial isa ports, initialize a new
+                * port and increment nr_uarts accordingly.
+                */
+               uart = serial8250_setup_port(nr_uarts);
+               if (!uart)
+                       goto unlock;
+               nr_uarts++;
+       }
+
+       if (uart->port.type != PORT_8250_CIR) {
                struct mctrl_gpios *gpios;
 
                if (uart->port.dev)
                        uart_remove_one_port(&serial8250_reg, &uart->port);
 
+               uart->port.ctrl_id      = up->port.ctrl_id;
                uart->port.iobase       = up->port.iobase;
                uart->port.membase      = up->port.membase;
                uart->port.irq          = up->port.irq;
@@ -1120,6 +1164,7 @@ int serial8250_register_8250_port(const struct uart_8250_port *up)
                }
        }
 
+unlock:
        mutex_unlock(&serial_mutex);
 
        return ret;
index 0ebde0a..4299a8b 100644 (file)
@@ -36,7 +36,6 @@
 
 static unsigned int serial8250_early_in(struct uart_port *port, int offset)
 {
-       int reg_offset = offset;
        offset <<= port->regshift;
 
        switch (port->iotype) {
@@ -50,8 +49,6 @@ static unsigned int serial8250_early_in(struct uart_port *port, int offset)
                return ioread32be(port->membase + offset);
        case UPIO_PORT:
                return inb(port->iobase + offset);
-       case UPIO_AU:
-               return port->serial_in(port, reg_offset);
        default:
                return 0;
        }
@@ -59,7 +56,6 @@ static unsigned int serial8250_early_in(struct uart_port *port, int offset)
 
 static void serial8250_early_out(struct uart_port *port, int offset, int value)
 {
-       int reg_offset = offset;
        offset <<= port->regshift;
 
        switch (port->iotype) {
@@ -78,9 +74,6 @@ static void serial8250_early_out(struct uart_port *port, int offset, int value)
        case UPIO_PORT:
                outb(value, port->iobase + offset);
                break;
-       case UPIO_AU:
-               port->serial_out(port, reg_offset, value);
-               break;
        }
 }
 
@@ -199,17 +192,3 @@ OF_EARLYCON_DECLARE(omap8250, "ti,omap3-uart", early_omap8250_setup);
 OF_EARLYCON_DECLARE(omap8250, "ti,omap4-uart", early_omap8250_setup);
 
 #endif
-
-#ifdef CONFIG_SERIAL_8250_RT288X
-
-static int __init early_au_setup(struct earlycon_device *dev, const char *opt)
-{
-       dev->port.serial_in = au_serial_in;
-       dev->port.serial_out = au_serial_out;
-       dev->port.iotype = UPIO_AU;
-       dev->con->write = early_serial8250_write;
-       return 0;
-}
-OF_EARLYCON_DECLARE(palmchip, "ralink,rt2880-uart", early_au_setup);
-
-#endif
index 25a9ecf..ef5019e 100644 (file)
@@ -139,12 +139,12 @@ static void serial8250_em_serial_out(struct uart_port *p, int offset, int value)
        }
 }
 
-static int serial8250_em_serial_dl_read(struct uart_8250_port *up)
+static u32 serial8250_em_serial_dl_read(struct uart_8250_port *up)
 {
        return serial_in(up, UART_DLL_EM) | serial_in(up, UART_DLM_EM) << 8;
 }
 
-static void serial8250_em_serial_dl_write(struct uart_8250_port *up, int value)
+static void serial8250_em_serial_dl_write(struct uart_8250_port *up, u32 value)
 {
        serial_out(up, UART_DLL_EM, value & 0xff);
        serial_out(up, UART_DLM_EM, value >> 8 & 0xff);
index b406cba..077c3ba 100644 (file)
@@ -198,8 +198,12 @@ static int xr17v35x_startup(struct uart_port *port)
        /*
         * Make sure all interrups are masked until initialization is
         * complete and the FIFOs are cleared
+        *
+        * Synchronize UART_IER access against the console.
         */
+       spin_lock_irq(&port->lock);
        serial_port_out(port, UART_IER, 0);
+       spin_unlock_irq(&port->lock);
 
        return serial8250_do_startup(port);
 }
index 8adfaa1..6af4e1c 100644 (file)
@@ -38,7 +38,19 @@ int fsl8250_handle_irq(struct uart_port *port)
                return 0;
        }
 
-       /* This is the WAR; if last event was BRK, then read and return */
+       /*
+        * For a single break the hardware reports LSR.BI for each character
+        * time. This is described in the MPC8313E chip errata as "General17".
+        * A typical break has a duration of 0.3s, with a 115200n8 configuration
+        * that (theoretically) corresponds to ~3500 interrupts in these 0.3s.
+        * In practise it's less (around 500) because of hardware
+        * and software latencies. The workaround recommended by the vendor is
+        * to read the RX register (to clear LSR.DR and thus prevent a FIFO
+        * aging interrupt). To prevent the irq from retriggering LSR must not be
+        * read. (This would clear LSR.BI, hardware would reassert the BI event
+        * immediately and interrupt the CPU again. The hardware clears LSR.BI
+        * when the next valid char is read.)
+        */
        if (unlikely(up->lsr_saved_flags & UART_LSR_BI)) {
                up->lsr_saved_flags &= ~UART_LSR_BI;
                port->serial_in(port, UART_RX);
@@ -172,3 +184,6 @@ static struct platform_driver fsl8250_platform_driver = {
 
 module_platform_driver(fsl8250_platform_driver);
 #endif
+
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("Handling of Freescale specific 8250 variants");
index fb1d5ec..74da567 100644 (file)
@@ -222,11 +222,17 @@ static void mtk8250_shutdown(struct uart_port *port)
 
 static void mtk8250_disable_intrs(struct uart_8250_port *up, int mask)
 {
+       /* Port locked to synchronize UART_IER access against the console. */
+       lockdep_assert_held_once(&up->port.lock);
+
        serial_out(up, UART_IER, serial_in(up, UART_IER) & (~mask));
 }
 
 static void mtk8250_enable_intrs(struct uart_8250_port *up, int mask)
 {
+       /* Port locked to synchronize UART_IER access against the console. */
+       lockdep_assert_held_once(&up->port.lock);
+
        serial_out(up, UART_IER, serial_in(up, UART_IER) | mask);
 }
 
@@ -235,6 +241,9 @@ static void mtk8250_set_flow_ctrl(struct uart_8250_port *up, int mode)
        struct uart_port *port = &up->port;
        int lcr = serial_in(up, UART_LCR);
 
+       /* Port locked to synchronize UART_IER access against the console. */
+       lockdep_assert_held_once(&port->lock);
+
        serial_out(up, UART_LCR, UART_LCR_CONF_MODE_B);
        serial_out(up, MTK_UART_EFR, UART_EFR_ECB);
        serial_out(up, UART_LCR, lcr);
@@ -422,12 +431,7 @@ static int __maybe_unused mtk8250_runtime_suspend(struct device *dev)
        while
                (serial_in(up, MTK_UART_DEBUG0));
 
-       if (data->clk_count == 0U) {
-               dev_dbg(dev, "%s clock count is 0\n", __func__);
-       } else {
-               clk_disable_unprepare(data->bus_clk);
-               data->clk_count--;
-       }
+       clk_disable_unprepare(data->bus_clk);
 
        return 0;
 }
@@ -435,19 +439,8 @@ static int __maybe_unused mtk8250_runtime_suspend(struct device *dev)
 static int __maybe_unused mtk8250_runtime_resume(struct device *dev)
 {
        struct mtk8250_data *data = dev_get_drvdata(dev);
-       int err;
 
-       if (data->clk_count > 0U) {
-               dev_dbg(dev, "%s clock count is %d\n", __func__,
-                       data->clk_count);
-       } else {
-               err = clk_prepare_enable(data->bus_clk);
-               if (err) {
-                       dev_warn(dev, "Can't enable bus clock\n");
-                       return err;
-               }
-               data->clk_count++;
-       }
+       clk_prepare_enable(data->bus_clk);
 
        return 0;
 }
@@ -456,14 +449,12 @@ static void
 mtk8250_do_pm(struct uart_port *port, unsigned int state, unsigned int old)
 {
        if (!state)
-               if (!mtk8250_runtime_resume(port->dev))
-                       pm_runtime_get_sync(port->dev);
+               pm_runtime_get_sync(port->dev);
 
        serial8250_do_pm(port, state, old);
 
        if (state)
-               if (!pm_runtime_put_sync_suspend(port->dev))
-                       mtk8250_runtime_suspend(port->dev);
+               pm_runtime_put_sync_suspend(port->dev);
 }
 
 #ifdef CONFIG_SERIAL_8250_DMA
@@ -495,7 +486,7 @@ static int mtk8250_probe_of(struct platform_device *pdev, struct uart_port *p,
                return 0;
        }
 
-       data->bus_clk = devm_clk_get(&pdev->dev, "bus");
+       data->bus_clk = devm_clk_get_enabled(&pdev->dev, "bus");
        if (IS_ERR(data->bus_clk))
                return PTR_ERR(data->bus_clk);
 
@@ -578,25 +569,16 @@ static int mtk8250_probe(struct platform_device *pdev)
 
        platform_set_drvdata(pdev, data);
 
-       pm_runtime_enable(&pdev->dev);
-       err = mtk8250_runtime_resume(&pdev->dev);
-       if (err)
-               goto err_pm_disable;
-
        data->line = serial8250_register_8250_port(&uart);
-       if (data->line < 0) {
-               err = data->line;
-               goto err_pm_disable;
-       }
+       if (data->line < 0)
+               return data->line;
 
        data->rx_wakeup_irq = platform_get_irq_optional(pdev, 1);
 
-       return 0;
-
-err_pm_disable:
-       pm_runtime_disable(&pdev->dev);
+       pm_runtime_set_active(&pdev->dev);
+       pm_runtime_enable(&pdev->dev);
 
-       return err;
+       return 0;
 }
 
 static int mtk8250_remove(struct platform_device *pdev)
@@ -610,9 +592,6 @@ static int mtk8250_remove(struct platform_device *pdev)
        pm_runtime_disable(&pdev->dev);
        pm_runtime_put_noidle(&pdev->dev);
 
-       if (!pm_runtime_status_suspended(&pdev->dev))
-               mtk8250_runtime_suspend(&pdev->dev);
-
        return 0;
 }
 
index 1b461fb..5132962 100644 (file)
@@ -171,11 +171,13 @@ static int of_platform_serial_setup(struct platform_device *ofdev,
 
        switch (type) {
        case PORT_RT2880:
-               port->iotype = UPIO_AU;
+               ret = rt288x_setup(port);
+               if (ret)
+                       goto err_unprepare;
                break;
        }
 
-       if (IS_ENABLED(CONFIG_SERIAL_8250_FSL) &&
+       if (IS_REACHABLE(CONFIG_SERIAL_8250_FSL) &&
            (of_device_is_compatible(np, "fsl,ns16550") ||
             of_device_is_compatible(np, "fsl,16550-FIFO64"))) {
                port->handle_irq = fsl8250_handle_irq;
index 734f092..d48a82f 100644 (file)
@@ -32,6 +32,7 @@
 #include "8250.h"
 
 #define DEFAULT_CLK_SPEED      48000000
+#define OMAP_UART_REGSHIFT     2
 
 #define UART_ERRATA_i202_MDR1_ACCESS   (1 << 0)
 #define OMAP_UART_WER_HAS_TX_WAKEUP    (1 << 1)
 #define UART_OMAP_RX_LVL               0x19
 
 struct omap8250_priv {
+       void __iomem *membase;
        int line;
        u8 habit;
        u8 mdr1;
@@ -159,9 +161,9 @@ static void omap_8250_rx_dma_flush(struct uart_8250_port *p);
 static inline void omap_8250_rx_dma_flush(struct uart_8250_port *p) { }
 #endif
 
-static u32 uart_read(struct uart_8250_port *up, u32 reg)
+static u32 uart_read(struct omap8250_priv *priv, u32 reg)
 {
-       return readl(up->port.membase + (reg << up->port.regshift));
+       return readl(priv->membase + (reg << OMAP_UART_REGSHIFT));
 }
 
 /*
@@ -302,6 +304,9 @@ static void omap8250_restore_regs(struct uart_8250_port *up)
        struct uart_8250_dma    *dma = up->dma;
        u8 mcr = serial8250_in_MCR(up);
 
+       /* Port locked to synchronize UART_IER access against the console. */
+       lockdep_assert_held_once(&up->port.lock);
+
        if (dma && dma->tx_running) {
                /*
                 * TCSANOW requests the change to occur immediately however if
@@ -523,6 +528,10 @@ static void omap_8250_pm(struct uart_port *port, unsigned int state,
        u8 efr;
 
        pm_runtime_get_sync(port->dev);
+
+       /* Synchronize UART_IER access against the console. */
+       spin_lock_irq(&port->lock);
+
        serial_out(up, UART_LCR, UART_LCR_CONF_MODE_B);
        efr = serial_in(up, UART_EFR);
        serial_out(up, UART_EFR, efr | UART_EFR_ECB);
@@ -533,6 +542,8 @@ static void omap_8250_pm(struct uart_port *port, unsigned int state,
        serial_out(up, UART_EFR, efr);
        serial_out(up, UART_LCR, 0);
 
+       spin_unlock_irq(&port->lock);
+
        pm_runtime_mark_last_busy(port->dev);
        pm_runtime_put_autosuspend(port->dev);
 }
@@ -548,7 +559,7 @@ static void omap_serial_fill_features_erratas(struct uart_8250_port *up,
        u32 mvr, scheme;
        u16 revision, major, minor;
 
-       mvr = uart_read(up, UART_OMAP_MVER);
+       mvr = uart_read(priv, UART_OMAP_MVER);
 
        /* Check revision register scheme */
        scheme = mvr >> OMAP_UART_MVR_SCHEME_SHIFT;
@@ -616,9 +627,9 @@ static int omap_8250_dma_handle_irq(struct uart_port *port);
 
 static irqreturn_t omap8250_irq(int irq, void *dev_id)
 {
-       struct uart_port *port = dev_id;
-       struct omap8250_priv *priv = port->private_data;
-       struct uart_8250_port *up = up_to_u8250p(port);
+       struct omap8250_priv *priv = dev_id;
+       struct uart_8250_port *up = serial8250_get_port(priv->line);
+       struct uart_port *port = &up->port;
        unsigned int iir, lsr;
        int ret;
 
@@ -649,6 +660,8 @@ static irqreturn_t omap8250_irq(int irq, void *dev_id)
        if ((lsr & UART_LSR_OE) && up->overrun_backoff_time_ms > 0) {
                unsigned long delay;
 
+               /* Synchronize UART_IER access against the console. */
+               spin_lock(&port->lock);
                up->ier = port->serial_in(port, UART_IER);
                if (up->ier & (UART_IER_RLSI | UART_IER_RDI)) {
                        port->ops->stop_rx(port);
@@ -658,6 +671,7 @@ static irqreturn_t omap8250_irq(int irq, void *dev_id)
                         */
                        cancel_delayed_work(&up->overrun_backoff);
                }
+               spin_unlock(&port->lock);
 
                delay = msecs_to_jiffies(up->overrun_backoff_time_ms);
                schedule_delayed_work(&up->overrun_backoff, delay);
@@ -672,6 +686,7 @@ static int omap_8250_startup(struct uart_port *port)
 {
        struct uart_8250_port *up = up_to_u8250p(port);
        struct omap8250_priv *priv = port->private_data;
+       struct uart_8250_dma *dma = &priv->omap8250_dma;
        int ret;
 
        if (priv->wakeirq) {
@@ -690,25 +705,23 @@ static int omap_8250_startup(struct uart_port *port)
        up->msr_saved_flags = 0;
 
        /* Disable DMA for console UART */
-       if (uart_console(port))
-               up->dma = NULL;
-
-       if (up->dma) {
+       if (dma->fn && !uart_console(port)) {
+               up->dma = &priv->omap8250_dma;
                ret = serial8250_request_dma(up);
                if (ret) {
                        dev_warn_ratelimited(port->dev,
                                             "failed to request DMA\n");
                        up->dma = NULL;
                }
+       } else {
+               up->dma = NULL;
        }
 
-       ret = request_irq(port->irq, omap8250_irq, IRQF_SHARED,
-                         dev_name(port->dev), port);
-       if (ret < 0)
-               goto err;
-
+       /* Synchronize UART_IER access against the console. */
+       spin_lock_irq(&port->lock);
        up->ier = UART_IER_RLSI | UART_IER_RDI;
        serial_out(up, UART_IER, up->ier);
+       spin_unlock_irq(&port->lock);
 
 #ifdef CONFIG_PM
        up->capabilities |= UART_CAP_RPM;
@@ -720,17 +733,17 @@ static int omap_8250_startup(struct uart_port *port)
                priv->wer |= OMAP_UART_TX_WAKEUP_EN;
        serial_out(up, UART_OMAP_WER, priv->wer);
 
-       if (up->dma && !(priv->habit & UART_HAS_EFR2))
+       if (up->dma && !(priv->habit & UART_HAS_EFR2)) {
+               spin_lock_irq(&port->lock);
                up->dma->rx_dma(up);
+               spin_unlock_irq(&port->lock);
+       }
+
+       enable_irq(up->port.irq);
 
        pm_runtime_mark_last_busy(port->dev);
        pm_runtime_put_autosuspend(port->dev);
        return 0;
-err:
-       pm_runtime_mark_last_busy(port->dev);
-       pm_runtime_put_autosuspend(port->dev);
-       dev_pm_clear_wake_irq(port->dev);
-       return ret;
 }
 
 static void omap_8250_shutdown(struct uart_port *port)
@@ -748,11 +761,16 @@ static void omap_8250_shutdown(struct uart_port *port)
        if (priv->habit & UART_HAS_EFR2)
                serial_out(up, UART_OMAP_EFR2, 0x0);
 
+       /* Synchronize UART_IER access against the console. */
+       spin_lock_irq(&port->lock);
        up->ier = 0;
        serial_out(up, UART_IER, 0);
+       spin_unlock_irq(&port->lock);
+       disable_irq_nosync(up->port.irq);
+       dev_pm_clear_wake_irq(port->dev);
 
-       if (up->dma)
-               serial8250_release_dma(up);
+       serial8250_release_dma(up);
+       up->dma = NULL;
 
        /*
         * Disable break condition and FIFOs
@@ -763,8 +781,6 @@ static void omap_8250_shutdown(struct uart_port *port)
 
        pm_runtime_mark_last_busy(port->dev);
        pm_runtime_put_autosuspend(port->dev);
-       free_irq(port->irq, port);
-       dev_pm_clear_wake_irq(port->dev);
 }
 
 static void omap_8250_throttle(struct uart_port *port)
@@ -791,6 +807,7 @@ static void omap_8250_unthrottle(struct uart_port *port)
 
        pm_runtime_get_sync(port->dev);
 
+       /* Synchronize UART_IER access against the console. */
        spin_lock_irqsave(&port->lock, flags);
        priv->throttled = false;
        if (up->dma)
@@ -941,6 +958,7 @@ static void __dma_rx_complete(void *param)
        struct dma_tx_state     state;
        unsigned long flags;
 
+       /* Synchronize UART_IER access against the console. */
        spin_lock_irqsave(&p->port.lock, flags);
 
        /*
@@ -998,6 +1016,9 @@ static int omap_8250_rx_dma(struct uart_8250_port *p)
        unsigned long                   flags;
        u32                             reg;
 
+       /* Port locked to synchronize UART_IER access against the console. */
+       lockdep_assert_held_once(&p->port.lock);
+
        if (priv->rx_dma_broken)
                return -EINVAL;
 
@@ -1212,6 +1233,9 @@ static u16 omap_8250_handle_rx_dma(struct uart_8250_port *up, u8 iir, u16 status
 static void am654_8250_handle_rx_dma(struct uart_8250_port *up, u8 iir,
                                     u16 status)
 {
+       /* Port locked to synchronize UART_IER access against the console. */
+       lockdep_assert_held_once(&up->port.lock);
+
        /*
         * Queue a new transfer if FIFO has data.
         */
@@ -1394,7 +1418,7 @@ static int omap8250_probe(struct platform_device *pdev)
                UPF_HARD_FLOW;
        up.port.private_data = priv;
 
-       up.port.regshift = 2;
+       up.port.regshift = OMAP_UART_REGSHIFT;
        up.port.fifosize = 64;
        up.tx_loadsz = 64;
        up.capabilities = UART_CAP_FIFO;
@@ -1444,8 +1468,6 @@ static int omap8250_probe(struct platform_device *pdev)
                                 &up.overrun_backoff_time_ms) != 0)
                up.overrun_backoff_time_ms = 0;
 
-       priv->wakeirq = irq_of_parse_and_map(np, 1);
-
        pdata = of_device_get_match_data(&pdev->dev);
        if (pdata)
                priv->habit |= pdata->habit;
@@ -1457,6 +1479,8 @@ static int omap8250_probe(struct platform_device *pdev)
                         DEFAULT_CLK_SPEED);
        }
 
+       priv->membase = membase;
+       priv->line = -ENODEV;
        priv->latency = PM_QOS_CPU_LATENCY_DEFAULT_VALUE;
        priv->calc_latency = PM_QOS_CPU_LATENCY_DEFAULT_VALUE;
        cpu_latency_qos_add_request(&priv->pm_qos_request, priv->latency);
@@ -1464,6 +1488,8 @@ static int omap8250_probe(struct platform_device *pdev)
 
        spin_lock_init(&priv->rx_dma_lock);
 
+       platform_set_drvdata(pdev, priv);
+
        device_init_wakeup(&pdev->dev, true);
        pm_runtime_enable(&pdev->dev);
        pm_runtime_use_autosuspend(&pdev->dev);
@@ -1498,64 +1524,77 @@ static int omap8250_probe(struct platform_device *pdev)
        ret = of_property_count_strings(np, "dma-names");
        if (ret == 2) {
                struct omap8250_dma_params *dma_params = NULL;
+               struct uart_8250_dma *dma = &priv->omap8250_dma;
 
-               up.dma = &priv->omap8250_dma;
-               up.dma->fn = the_no_dma_filter_fn;
-               up.dma->tx_dma = omap_8250_tx_dma;
-               up.dma->rx_dma = omap_8250_rx_dma;
+               dma->fn = the_no_dma_filter_fn;
+               dma->tx_dma = omap_8250_tx_dma;
+               dma->rx_dma = omap_8250_rx_dma;
                if (pdata)
                        dma_params = pdata->dma_params;
 
                if (dma_params) {
-                       up.dma->rx_size = dma_params->rx_size;
-                       up.dma->rxconf.src_maxburst = dma_params->rx_trigger;
-                       up.dma->txconf.dst_maxburst = dma_params->tx_trigger;
+                       dma->rx_size = dma_params->rx_size;
+                       dma->rxconf.src_maxburst = dma_params->rx_trigger;
+                       dma->txconf.dst_maxburst = dma_params->tx_trigger;
                        priv->rx_trigger = dma_params->rx_trigger;
                        priv->tx_trigger = dma_params->tx_trigger;
                } else {
-                       up.dma->rx_size = RX_TRIGGER;
-                       up.dma->rxconf.src_maxburst = RX_TRIGGER;
-                       up.dma->txconf.dst_maxburst = TX_TRIGGER;
+                       dma->rx_size = RX_TRIGGER;
+                       dma->rxconf.src_maxburst = RX_TRIGGER;
+                       dma->txconf.dst_maxburst = TX_TRIGGER;
                }
        }
 #endif
+
+       irq_set_status_flags(irq, IRQ_NOAUTOEN);
+       ret = devm_request_irq(&pdev->dev, irq, omap8250_irq, 0,
+                              dev_name(&pdev->dev), priv);
+       if (ret < 0)
+               return ret;
+
+       priv->wakeirq = irq_of_parse_and_map(np, 1);
+
        ret = serial8250_register_8250_port(&up);
        if (ret < 0) {
                dev_err(&pdev->dev, "unable to register 8250 port\n");
                goto err;
        }
        priv->line = ret;
-       platform_set_drvdata(pdev, priv);
        pm_runtime_mark_last_busy(&pdev->dev);
        pm_runtime_put_autosuspend(&pdev->dev);
        return 0;
 err:
        pm_runtime_dont_use_autosuspend(&pdev->dev);
        pm_runtime_put_sync(&pdev->dev);
+       flush_work(&priv->qos_work);
        pm_runtime_disable(&pdev->dev);
+       cpu_latency_qos_remove_request(&priv->pm_qos_request);
        return ret;
 }
 
 static int omap8250_remove(struct platform_device *pdev)
 {
        struct omap8250_priv *priv = platform_get_drvdata(pdev);
+       struct uart_8250_port *up;
        int err;
 
        err = pm_runtime_resume_and_get(&pdev->dev);
        if (err)
                return err;
 
+       up = serial8250_get_port(priv->line);
+       omap_8250_shutdown(&up->port);
+       serial8250_unregister_port(priv->line);
+       priv->line = -ENODEV;
        pm_runtime_dont_use_autosuspend(&pdev->dev);
        pm_runtime_put_sync(&pdev->dev);
        flush_work(&priv->qos_work);
        pm_runtime_disable(&pdev->dev);
-       serial8250_unregister_port(priv->line);
        cpu_latency_qos_remove_request(&priv->pm_qos_request);
        device_init_wakeup(&pdev->dev, false);
        return 0;
 }
 
-#ifdef CONFIG_PM_SLEEP
 static int omap8250_prepare(struct device *dev)
 {
        struct omap8250_priv *priv = dev_get_drvdata(dev);
@@ -1579,33 +1618,38 @@ static int omap8250_suspend(struct device *dev)
 {
        struct omap8250_priv *priv = dev_get_drvdata(dev);
        struct uart_8250_port *up = serial8250_get_port(priv->line);
+       int err;
 
        serial8250_suspend_port(priv->line);
 
-       pm_runtime_get_sync(dev);
+       err = pm_runtime_resume_and_get(dev);
+       if (err)
+               return err;
        if (!device_may_wakeup(dev))
                priv->wer = 0;
        serial_out(up, UART_OMAP_WER, priv->wer);
-       pm_runtime_mark_last_busy(dev);
-       pm_runtime_put_autosuspend(dev);
-
+       err = pm_runtime_force_suspend(dev);
        flush_work(&priv->qos_work);
-       return 0;
+
+       return err;
 }
 
 static int omap8250_resume(struct device *dev)
 {
        struct omap8250_priv *priv = dev_get_drvdata(dev);
+       int err;
 
+       err = pm_runtime_force_resume(dev);
+       if (err)
+               return err;
        serial8250_resume_port(priv->line);
+       /* Paired with pm_runtime_resume_and_get() in omap8250_suspend() */
+       pm_runtime_mark_last_busy(dev);
+       pm_runtime_put_autosuspend(dev);
+
        return 0;
 }
-#else
-#define omap8250_prepare NULL
-#define omap8250_complete NULL
-#endif
 
-#ifdef CONFIG_PM
 static int omap8250_lost_context(struct uart_8250_port *up)
 {
        u32 val;
@@ -1621,11 +1665,15 @@ static int omap8250_lost_context(struct uart_8250_port *up)
        return 0;
 }
 
+static void uart_write(struct omap8250_priv *priv, u32 reg, u32 val)
+{
+       writel(val, priv->membase + (reg << OMAP_UART_REGSHIFT));
+}
+
 /* TODO: in future, this should happen via API in drivers/reset/ */
 static int omap8250_soft_reset(struct device *dev)
 {
        struct omap8250_priv *priv = dev_get_drvdata(dev);
-       struct uart_8250_port *up = serial8250_get_port(priv->line);
        int timeout = 100;
        int sysc;
        int syss;
@@ -1639,20 +1687,20 @@ static int omap8250_soft_reset(struct device *dev)
         * needing omap8250_soft_reset() quirk. Do it in two writes as
         * recommended in the comment for omap8250_update_scr().
         */
-       serial_out(up, UART_OMAP_SCR, OMAP_UART_SCR_DMAMODE_1);
-       serial_out(up, UART_OMAP_SCR,
+       uart_write(priv, UART_OMAP_SCR, OMAP_UART_SCR_DMAMODE_1);
+       uart_write(priv, UART_OMAP_SCR,
                   OMAP_UART_SCR_DMAMODE_1 | OMAP_UART_SCR_DMAMODE_CTL);
 
-       sysc = serial_in(up, UART_OMAP_SYSC);
+       sysc = uart_read(priv, UART_OMAP_SYSC);
 
        /* softreset the UART */
        sysc |= OMAP_UART_SYSC_SOFTRESET;
-       serial_out(up, UART_OMAP_SYSC, sysc);
+       uart_write(priv, UART_OMAP_SYSC, sysc);
 
        /* By experiments, 1us enough for reset complete on AM335x */
        do {
                udelay(1);
-               syss = serial_in(up, UART_OMAP_SYSS);
+               syss = uart_read(priv, UART_OMAP_SYSS);
        } while (--timeout && !(syss & OMAP_UART_SYSS_RESETDONE));
 
        if (!timeout) {
@@ -1666,13 +1714,10 @@ static int omap8250_soft_reset(struct device *dev)
 static int omap8250_runtime_suspend(struct device *dev)
 {
        struct omap8250_priv *priv = dev_get_drvdata(dev);
-       struct uart_8250_port *up;
-
-       /* In case runtime-pm tries this before we are setup */
-       if (!priv)
-               return 0;
+       struct uart_8250_port *up = NULL;
 
-       up = serial8250_get_port(priv->line);
+       if (priv->line >= 0)
+               up = serial8250_get_port(priv->line);
        /*
         * When using 'no_console_suspend', the console UART must not be
         * suspended. Since driver suspend is managed by runtime suspend,
@@ -1680,7 +1725,7 @@ static int omap8250_runtime_suspend(struct device *dev)
         * active during suspend.
         */
        if (priv->is_suspending && !console_suspend_enabled) {
-               if (uart_console(&up->port))
+               if (up && uart_console(&up->port))
                        return -EBUSY;
        }
 
@@ -1691,13 +1736,15 @@ static int omap8250_runtime_suspend(struct device *dev)
                if (ret)
                        return ret;
 
-               /* Restore to UART mode after reset (for wakeup) */
-               omap8250_update_mdr1(up, priv);
-               /* Restore wakeup enable register */
-               serial_out(up, UART_OMAP_WER, priv->wer);
+               if (up) {
+                       /* Restore to UART mode after reset (for wakeup) */
+                       omap8250_update_mdr1(up, priv);
+                       /* Restore wakeup enable register */
+                       serial_out(up, UART_OMAP_WER, priv->wer);
+               }
        }
 
-       if (up->dma && up->dma->rxchan)
+       if (up && up->dma && up->dma->rxchan)
                omap_8250_rx_dma_flush(up);
 
        priv->latency = PM_QOS_CPU_LATENCY_DEFAULT_VALUE;
@@ -1709,25 +1756,27 @@ static int omap8250_runtime_suspend(struct device *dev)
 static int omap8250_runtime_resume(struct device *dev)
 {
        struct omap8250_priv *priv = dev_get_drvdata(dev);
-       struct uart_8250_port *up;
-
-       /* In case runtime-pm tries this before we are setup */
-       if (!priv)
-               return 0;
+       struct uart_8250_port *up = NULL;
 
-       up = serial8250_get_port(priv->line);
+       if (priv->line >= 0)
+               up = serial8250_get_port(priv->line);
 
-       if (omap8250_lost_context(up))
+       if (up && omap8250_lost_context(up)) {
+               spin_lock_irq(&up->port.lock);
                omap8250_restore_regs(up);
+               spin_unlock_irq(&up->port.lock);
+       }
 
-       if (up->dma && up->dma->rxchan && !(priv->habit & UART_HAS_EFR2))
+       if (up && up->dma && up->dma->rxchan && !(priv->habit & UART_HAS_EFR2)) {
+               spin_lock_irq(&up->port.lock);
                omap_8250_rx_dma(up);
+               spin_unlock_irq(&up->port.lock);
+       }
 
        priv->latency = priv->calc_latency;
        schedule_work(&priv->qos_work);
        return 0;
 }
-#endif
 
 #ifdef CONFIG_SERIAL_8250_OMAP_TTYO_FIXUP
 static int __init omap8250_console_fixup(void)
@@ -1770,17 +1819,17 @@ console_initcall(omap8250_console_fixup);
 #endif
 
 static const struct dev_pm_ops omap8250_dev_pm_ops = {
-       SET_SYSTEM_SLEEP_PM_OPS(omap8250_suspend, omap8250_resume)
-       SET_RUNTIME_PM_OPS(omap8250_runtime_suspend,
+       SYSTEM_SLEEP_PM_OPS(omap8250_suspend, omap8250_resume)
+       RUNTIME_PM_OPS(omap8250_runtime_suspend,
                           omap8250_runtime_resume, NULL)
-       .prepare        = omap8250_prepare,
-       .complete       = omap8250_complete,
+       .prepare        = pm_sleep_ptr(omap8250_prepare),
+       .complete       = pm_sleep_ptr(omap8250_complete),
 };
 
 static struct platform_driver omap8250_platform_driver = {
        .driver = {
                .name           = "omap8250",
-               .pm             = &omap8250_dev_pm_ops,
+               .pm             = pm_ptr(&omap8250_dev_pm_ops),
                .of_match_table = omap8250_dt_ids,
        },
        .probe                  = omap8250_probe,
index e80c4f6..d2d547b 100644 (file)
@@ -1232,14 +1232,6 @@ static int pci_oxsemi_tornado_setup(struct serial_private *priv,
        return pci_default_setup(priv, board, up, idx);
 }
 
-static int pci_asix_setup(struct serial_private *priv,
-                 const struct pciserial_board *board,
-                 struct uart_8250_port *port, int idx)
-{
-       port->bugs |= UART_BUG_PARITY;
-       return pci_default_setup(priv, board, port, idx);
-}
-
 #define QPCR_TEST_FOR1         0x3F
 #define QPCR_TEST_GET1         0x00
 #define QPCR_TEST_FOR2         0x40
@@ -1955,7 +1947,6 @@ pci_moxa_setup(struct serial_private *priv,
 #define PCI_DEVICE_ID_WCH_CH355_4S     0x7173
 #define PCI_VENDOR_ID_AGESTAR          0x5372
 #define PCI_DEVICE_ID_AGESTAR_9375     0x6872
-#define PCI_VENDOR_ID_ASIX             0x9710
 #define PCI_DEVICE_ID_BROADCOM_TRUMANAGE 0x160a
 #define PCI_DEVICE_ID_AMCC_ADDIDATA_APCI7800 0x818e
 
@@ -2601,16 +2592,6 @@ static struct pci_serial_quirk pci_serial_quirks[] = {
                .setup          = pci_wch_ch38x_setup,
        },
        /*
-        * ASIX devices with FIFO bug
-        */
-       {
-               .vendor         = PCI_VENDOR_ID_ASIX,
-               .device         = PCI_ANY_ID,
-               .subvendor      = PCI_ANY_ID,
-               .subdevice      = PCI_ANY_ID,
-               .setup          = pci_asix_setup,
-       },
-       /*
         * Broadcom TruManage (NetXtreme)
         */
        {
index c153ba3..16aeb14 100644 (file)
@@ -325,7 +325,7 @@ static const struct serial8250_config uart_config[] = {
 };
 
 /* Uart divisor latch read */
-static int default_serial_dl_read(struct uart_8250_port *up)
+static u32 default_serial_dl_read(struct uart_8250_port *up)
 {
        /* Assign these in pieces to truncate any bits above 7.  */
        unsigned char dll = serial_in(up, UART_DLL);
@@ -335,72 +335,12 @@ static int default_serial_dl_read(struct uart_8250_port *up)
 }
 
 /* Uart divisor latch write */
-static void default_serial_dl_write(struct uart_8250_port *up, int value)
+static void default_serial_dl_write(struct uart_8250_port *up, u32 value)
 {
        serial_out(up, UART_DLL, value & 0xff);
        serial_out(up, UART_DLM, value >> 8 & 0xff);
 }
 
-#ifdef CONFIG_SERIAL_8250_RT288X
-
-#define UART_REG_UNMAPPED      -1
-
-/* Au1x00/RT288x UART hardware has a weird register layout */
-static const s8 au_io_in_map[8] = {
-       [UART_RX]       = 0,
-       [UART_IER]      = 2,
-       [UART_IIR]      = 3,
-       [UART_LCR]      = 5,
-       [UART_MCR]      = 6,
-       [UART_LSR]      = 7,
-       [UART_MSR]      = 8,
-       [UART_SCR]      = UART_REG_UNMAPPED,
-};
-
-static const s8 au_io_out_map[8] = {
-       [UART_TX]       = 1,
-       [UART_IER]      = 2,
-       [UART_FCR]      = 4,
-       [UART_LCR]      = 5,
-       [UART_MCR]      = 6,
-       [UART_LSR]      = UART_REG_UNMAPPED,
-       [UART_MSR]      = UART_REG_UNMAPPED,
-       [UART_SCR]      = UART_REG_UNMAPPED,
-};
-
-unsigned int au_serial_in(struct uart_port *p, int offset)
-{
-       if (offset >= ARRAY_SIZE(au_io_in_map))
-               return UINT_MAX;
-       offset = au_io_in_map[offset];
-       if (offset == UART_REG_UNMAPPED)
-               return UINT_MAX;
-       return __raw_readl(p->membase + (offset << p->regshift));
-}
-
-void au_serial_out(struct uart_port *p, int offset, int value)
-{
-       if (offset >= ARRAY_SIZE(au_io_out_map))
-               return;
-       offset = au_io_out_map[offset];
-       if (offset == UART_REG_UNMAPPED)
-               return;
-       __raw_writel(value, p->membase + (offset << p->regshift));
-}
-
-/* Au1x00 haven't got a standard divisor latch */
-static int au_serial_dl_read(struct uart_8250_port *up)
-{
-       return __raw_readl(up->port.membase + 0x28);
-}
-
-static void au_serial_dl_write(struct uart_8250_port *up, int value)
-{
-       __raw_writel(value, up->port.membase + 0x28);
-}
-
-#endif
-
 static unsigned int hub6_serial_in(struct uart_port *p, int offset)
 {
        offset = offset << p->regshift;
@@ -510,15 +450,6 @@ static void set_io_from_upio(struct uart_port *p)
                p->serial_out = mem32be_serial_out;
                break;
 
-#ifdef CONFIG_SERIAL_8250_RT288X
-       case UPIO_AU:
-               p->serial_in = au_serial_in;
-               p->serial_out = au_serial_out;
-               up->dl_read = au_serial_dl_read;
-               up->dl_write = au_serial_dl_write;
-               break;
-#endif
-
        default:
                p->serial_in = io_serial_in;
                p->serial_out = io_serial_out;
@@ -608,6 +539,9 @@ EXPORT_SYMBOL_GPL(serial8250_rpm_put);
  */
 static int serial8250_em485_init(struct uart_8250_port *p)
 {
+       /* Port locked to synchronize UART_IER access against the console. */
+       lockdep_assert_held_once(&p->port.lock);
+
        if (p->em485)
                goto deassert_rts;
 
@@ -746,6 +680,8 @@ static void serial8250_set_sleep(struct uart_8250_port *p, int sleep)
        serial8250_rpm_get(p);
 
        if (p->capabilities & UART_CAP_SLEEP) {
+               /* Synchronize UART_IER access against the console. */
+               spin_lock_irq(&p->port.lock);
                if (p->capabilities & UART_CAP_EFR) {
                        lcr = serial_in(p, UART_LCR);
                        efr = serial_in(p, UART_EFR);
@@ -759,6 +695,7 @@ static void serial8250_set_sleep(struct uart_8250_port *p, int sleep)
                        serial_out(p, UART_EFR, efr);
                        serial_out(p, UART_LCR, lcr);
                }
+               spin_unlock_irq(&p->port.lock);
        }
 
        serial8250_rpm_put(p);
@@ -766,6 +703,9 @@ static void serial8250_set_sleep(struct uart_8250_port *p, int sleep)
 
 static void serial8250_clear_IER(struct uart_8250_port *up)
 {
+       /* Port locked to synchronize UART_IER access against the console. */
+       lockdep_assert_held_once(&up->port.lock);
+
        if (up->capabilities & UART_CAP_UUE)
                serial_out(up, UART_IER, UART_IER_UUE);
        else
@@ -848,7 +788,7 @@ static void disable_rsa(struct uart_8250_port *up)
 static int size_fifo(struct uart_8250_port *up)
 {
        unsigned char old_fcr, old_mcr, old_lcr;
-       unsigned short old_dl;
+       u32 old_dl;
        int count;
 
        old_lcr = serial_in(up, UART_LCR);
@@ -1038,6 +978,9 @@ static void autoconfig_16550a(struct uart_8250_port *up)
        unsigned char status1, status2;
        unsigned int iersave;
 
+       /* Port locked to synchronize UART_IER access against the console. */
+       lockdep_assert_held_once(&up->port.lock);
+
        up->port.type = PORT_16550A;
        up->capabilities |= UART_CAP_FIFO;
 
@@ -1221,6 +1164,8 @@ static void autoconfig(struct uart_8250_port *up)
        /*
         * We really do need global IRQs disabled here - we're going to
         * be frobbing the chips IRQ enable register to see if it exists.
+        *
+        * Synchronize UART_IER access against the console.
         */
        spin_lock_irqsave(&port->lock, flags);
 
@@ -1393,7 +1338,10 @@ static void autoconfig_irq(struct uart_8250_port *up)
        /* forget possible initially masked and pending IRQ */
        probe_irq_off(probe_irq_on());
        save_mcr = serial8250_in_MCR(up);
+       /* Synchronize UART_IER access against the console. */
+       spin_lock_irq(&port->lock);
        save_ier = serial_in(up, UART_IER);
+       spin_unlock_irq(&port->lock);
        serial8250_out_MCR(up, UART_MCR_OUT1 | UART_MCR_OUT2);
 
        irqs = probe_irq_on();
@@ -1405,7 +1353,10 @@ static void autoconfig_irq(struct uart_8250_port *up)
                serial8250_out_MCR(up,
                        UART_MCR_DTR | UART_MCR_RTS | UART_MCR_OUT2);
        }
+       /* Synchronize UART_IER access against the console. */
+       spin_lock_irq(&port->lock);
        serial_out(up, UART_IER, UART_IER_ALL_INTR);
+       spin_unlock_irq(&port->lock);
        serial_in(up, UART_LSR);
        serial_in(up, UART_RX);
        serial_in(up, UART_IIR);
@@ -1415,7 +1366,10 @@ static void autoconfig_irq(struct uart_8250_port *up)
        irq = probe_irq_off(irqs);
 
        serial8250_out_MCR(up, save_mcr);
+       /* Synchronize UART_IER access against the console. */
+       spin_lock_irq(&port->lock);
        serial_out(up, UART_IER, save_ier);
+       spin_unlock_irq(&port->lock);
 
        if (port->flags & UPF_FOURPORT)
                outb_p(save_ICP, ICP);
@@ -1430,6 +1384,9 @@ static void serial8250_stop_rx(struct uart_port *port)
 {
        struct uart_8250_port *up = up_to_u8250p(port);
 
+       /* Port locked to synchronize UART_IER access against the console. */
+       lockdep_assert_held_once(&port->lock);
+
        serial8250_rpm_get(up);
 
        up->ier &= ~(UART_IER_RLSI | UART_IER_RDI);
@@ -1449,6 +1406,9 @@ void serial8250_em485_stop_tx(struct uart_8250_port *p)
 {
        unsigned char mcr = serial8250_in_MCR(p);
 
+       /* Port locked to synchronize UART_IER access against the console. */
+       lockdep_assert_held_once(&p->port.lock);
+
        if (p->port.rs485.flags & SER_RS485_RTS_AFTER_SEND)
                mcr |= UART_MCR_RTS;
        else
@@ -1498,6 +1458,9 @@ static void __stop_tx_rs485(struct uart_8250_port *p, u64 stop_delay)
 {
        struct uart_8250_em485 *em485 = p->em485;
 
+       /* Port locked to synchronize UART_IER access against the console. */
+       lockdep_assert_held_once(&p->port.lock);
+
        stop_delay += (u64)p->port.rs485.delay_rts_after_send * NSEC_PER_MSEC;
 
        /*
@@ -1677,6 +1640,9 @@ static void serial8250_start_tx(struct uart_port *port)
        struct uart_8250_port *up = up_to_u8250p(port);
        struct uart_8250_em485 *em485 = up->em485;
 
+       /* Port locked to synchronize UART_IER access against the console. */
+       lockdep_assert_held_once(&port->lock);
+
        if (!port->x_char && uart_circ_empty(&port->state->xmit))
                return;
 
@@ -1704,6 +1670,9 @@ static void serial8250_disable_ms(struct uart_port *port)
 {
        struct uart_8250_port *up = up_to_u8250p(port);
 
+       /* Port locked to synchronize UART_IER access against the console. */
+       lockdep_assert_held_once(&port->lock);
+
        /* no MSR capabilities */
        if (up->bugs & UART_BUG_NOMSR)
                return;
@@ -1718,6 +1687,9 @@ static void serial8250_enable_ms(struct uart_port *port)
 {
        struct uart_8250_port *up = up_to_u8250p(port);
 
+       /* Port locked to synchronize UART_IER access against the console. */
+       lockdep_assert_held_once(&port->lock);
+
        /* no MSR capabilities */
        if (up->bugs & UART_BUG_NOMSR)
                return;
@@ -2174,6 +2146,14 @@ static void serial8250_put_poll_char(struct uart_port *port,
        unsigned int ier;
        struct uart_8250_port *up = up_to_u8250p(port);
 
+       /*
+        * Normally the port is locked to synchronize UART_IER access
+        * against the console. However, this function is only used by
+        * KDB/KGDB, where it may not be possible to acquire the port
+        * lock because all other CPUs are quiesced. The quiescence
+        * should allow safe lockless usage here.
+        */
+
        serial8250_rpm_get(up);
        /*
         *      First save the IER then disable the interrupts
@@ -2219,7 +2199,12 @@ int serial8250_do_startup(struct uart_port *port)
 
        serial8250_rpm_get(up);
        if (port->type == PORT_16C950) {
-               /* Wake up and initialize UART */
+               /*
+                * Wake up and initialize UART
+                *
+                * Synchronize UART_IER access against the console.
+                */
+               spin_lock_irqsave(&port->lock, flags);
                up->acr = 0;
                serial_port_out(port, UART_LCR, UART_LCR_CONF_MODE_B);
                serial_port_out(port, UART_EFR, UART_EFR_ECB);
@@ -2229,12 +2214,19 @@ int serial8250_do_startup(struct uart_port *port)
                serial_port_out(port, UART_LCR, UART_LCR_CONF_MODE_B);
                serial_port_out(port, UART_EFR, UART_EFR_ECB);
                serial_port_out(port, UART_LCR, 0);
+               spin_unlock_irqrestore(&port->lock, flags);
        }
 
        if (port->type == PORT_DA830) {
-               /* Reset the port */
+               /*
+                * Reset the port
+                *
+                * Synchronize UART_IER access against the console.
+                */
+               spin_lock_irqsave(&port->lock, flags);
                serial_port_out(port, UART_IER, 0);
                serial_port_out(port, UART_DA830_PWREMU_MGMT, 0);
+               spin_unlock_irqrestore(&port->lock, flags);
                mdelay(10);
 
                /* Enable Tx, Rx and free run mode */
@@ -2345,6 +2337,8 @@ int serial8250_do_startup(struct uart_port *port)
                 * this interrupt whenever the transmitter is idle and
                 * the interrupt is enabled.  Delays are necessary to
                 * allow register changes to become visible.
+                *
+                * Synchronize UART_IER access against the console.
                 */
                spin_lock_irqsave(&port->lock, flags);
 
@@ -2495,6 +2489,8 @@ void serial8250_do_shutdown(struct uart_port *port)
        serial8250_rpm_get(up);
        /*
         * Disable interrupts from this port
+        *
+        * Synchronize UART_IER access against the console.
         */
        spin_lock_irqsave(&port->lock, flags);
        up->ier = 0;
@@ -2636,11 +2632,8 @@ static unsigned char serial8250_compute_lcr(struct uart_8250_port *up,
 
        if (c_cflag & CSTOPB)
                cval |= UART_LCR_STOP;
-       if (c_cflag & PARENB) {
+       if (c_cflag & PARENB)
                cval |= UART_LCR_PARITY;
-               if (up->bugs & UART_BUG_PARITY)
-                       up->fifo_bug = true;
-       }
        if (!(c_cflag & PARODD))
                cval |= UART_LCR_EPAR;
        if (c_cflag & CMSPAR)
@@ -2794,6 +2787,8 @@ serial8250_do_set_termios(struct uart_port *port, struct ktermios *termios,
        /*
         * Ok, we're now changing the port state.  Do it with
         * interrupts disabled.
+        *
+        * Synchronize UART_IER access against the console.
         */
        serial8250_rpm_get(up);
        spin_lock_irqsave(&port->lock, flags);
@@ -2801,8 +2796,7 @@ serial8250_do_set_termios(struct uart_port *port, struct ktermios *termios,
        up->lcr = cval;                                 /* Save computed LCR */
 
        if (up->capabilities & UART_CAP_FIFO && port->fifosize > 1) {
-               /* NOTE: If fifo_bug is not set, a user can set RX_trigger. */
-               if ((baud < 2400 && !up->dma) || up->fifo_bug) {
+               if (baud < 2400 && !up->dma) {
                        up->fcr &= ~UART_FCR_TRIGGER_MASK;
                        up->fcr |= UART_FCR_TRIGGER_1;
                }
@@ -2969,11 +2963,6 @@ static unsigned int serial8250_port_size(struct uart_8250_port *pt)
 {
        if (pt->port.mapsize)
                return pt->port.mapsize;
-       if (pt->port.iotype == UPIO_AU) {
-               if (pt->port.type == PORT_RT2880)
-                       return 0x100;
-               return 0x1000;
-       }
        if (is_omap1_8250(pt))
                return 0x16 << pt->port.regshift;
 
@@ -3138,8 +3127,7 @@ static int do_set_rxtrig(struct tty_port *port, unsigned char bytes)
        struct uart_8250_port *up = up_to_u8250p(uport);
        int rxtrig;
 
-       if (!(up->capabilities & UART_CAP_FIFO) || uport->fifosize <= 1 ||
-           up->fifo_bug)
+       if (!(up->capabilities & UART_CAP_FIFO) || uport->fifosize <= 1)
                return -EINVAL;
 
        rxtrig = bytes_to_fcr_rxtrig(up, bytes);
@@ -3223,10 +3211,6 @@ static void serial8250_config_port(struct uart_port *port, int flags)
        if (flags & UART_CONFIG_TYPE)
                autoconfig(up);
 
-       /* if access method is AU, it is a 16550 with a quirk */
-       if (port->type == PORT_16550A && port->iotype == UPIO_AU)
-               up->bugs |= UART_BUG_NOMSR;
-
        /* HW bugs may trigger IRQ while IIR == NO_INT */
        if (port->type == PORT_TEGRA)
                up->bugs |= UART_BUG_NOMSR;
@@ -3293,6 +3277,7 @@ void serial8250_init_port(struct uart_8250_port *up)
        struct uart_port *port = &up->port;
 
        spin_lock_init(&port->lock);
+       port->ctrl_id = 0;
        port->ops = &serial8250_pops;
        port->has_sysrq = IS_ENABLED(CONFIG_SERIAL_8250_CONSOLE);
 
index 795e551..28b341f 100644 (file)
@@ -60,7 +60,7 @@ static const struct of_device_id serial_pxa_dt_ids[] = {
 MODULE_DEVICE_TABLE(of, serial_pxa_dt_ids);
 
 /* Uart divisor latch write */
-static void serial_pxa_dl_write(struct uart_8250_port *up, int value)
+static void serial_pxa_dl_write(struct uart_8250_port *up, u32 value)
 {
        unsigned int dll;
 
diff --git a/drivers/tty/serial/8250/8250_rt288x.c b/drivers/tty/serial/8250/8250_rt288x.c
new file mode 100644 (file)
index 0000000..6415ca8
--- /dev/null
@@ -0,0 +1,136 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * RT288x/Au1xxx driver
+ */
+
+#include <linux/module.h>
+#include <linux/io.h>
+#include <linux/init.h>
+#include <linux/console.h>
+#include <linux/serial.h>
+#include <linux/serial_8250.h>
+
+#include "8250.h"
+
+#define RT288X_DL      0x28
+
+/* Au1x00/RT288x UART hardware has a weird register layout */
+static const u8 au_io_in_map[7] = {
+       [UART_RX]       = 0,
+       [UART_IER]      = 2,
+       [UART_IIR]      = 3,
+       [UART_LCR]      = 5,
+       [UART_MCR]      = 6,
+       [UART_LSR]      = 7,
+       [UART_MSR]      = 8,
+};
+
+static const u8 au_io_out_map[5] = {
+       [UART_TX]       = 1,
+       [UART_IER]      = 2,
+       [UART_FCR]      = 4,
+       [UART_LCR]      = 5,
+       [UART_MCR]      = 6,
+};
+
+static unsigned int au_serial_in(struct uart_port *p, int offset)
+{
+       if (offset >= ARRAY_SIZE(au_io_in_map))
+               return UINT_MAX;
+       offset = au_io_in_map[offset];
+
+       return __raw_readl(p->membase + (offset << p->regshift));
+}
+
+static void au_serial_out(struct uart_port *p, int offset, int value)
+{
+       if (offset >= ARRAY_SIZE(au_io_out_map))
+               return;
+       offset = au_io_out_map[offset];
+
+       __raw_writel(value, p->membase + (offset << p->regshift));
+}
+
+/* Au1x00 haven't got a standard divisor latch */
+static u32 au_serial_dl_read(struct uart_8250_port *up)
+{
+       return __raw_readl(up->port.membase + RT288X_DL);
+}
+
+static void au_serial_dl_write(struct uart_8250_port *up, u32 value)
+{
+       __raw_writel(value, up->port.membase + RT288X_DL);
+}
+
+int au_platform_setup(struct plat_serial8250_port *p)
+{
+       p->iotype = UPIO_AU;
+
+       p->serial_in = au_serial_in;
+       p->serial_out = au_serial_out;
+       p->dl_read = au_serial_dl_read;
+       p->dl_write = au_serial_dl_write;
+
+       p->mapsize = 0x1000;
+
+       p->bugs |= UART_BUG_NOMSR;
+
+       return 0;
+}
+EXPORT_SYMBOL_GPL(au_platform_setup);
+
+int rt288x_setup(struct uart_port *p)
+{
+       struct uart_8250_port *up = up_to_u8250p(p);
+
+       p->iotype = UPIO_AU;
+
+       p->serial_in = au_serial_in;
+       p->serial_out = au_serial_out;
+       up->dl_read = au_serial_dl_read;
+       up->dl_write = au_serial_dl_write;
+
+       p->mapsize = 0x100;
+
+       up->bugs |= UART_BUG_NOMSR;
+
+       return 0;
+}
+EXPORT_SYMBOL_GPL(rt288x_setup);
+
+#ifdef CONFIG_SERIAL_8250_CONSOLE
+static void au_putc(struct uart_port *port, unsigned char c)
+{
+       unsigned int status;
+
+       au_serial_out(port, UART_TX, c);
+
+       for (;;) {
+               status = au_serial_in(port, UART_LSR);
+               if (uart_lsr_tx_empty(status))
+                       break;
+               cpu_relax();
+       }
+}
+
+static void au_early_serial8250_write(struct console *console,
+                                     const char *s, unsigned int count)
+{
+       struct earlycon_device *device = console->data;
+       struct uart_port *port = &device->port;
+
+       uart_console_write(port, s, count, au_putc);
+}
+
+static int __init early_au_setup(struct earlycon_device *dev, const char *opt)
+{
+       rt288x_setup(&dev->port);
+       dev->con->write = au_early_serial8250_write;
+
+       return 0;
+}
+OF_EARLYCON_DECLARE(palmchip, "ralink,rt2880-uart", early_au_setup);
+#endif
+
+MODULE_DESCRIPTION("RT288x/Au1xxx UART driver");
+MODULE_LICENSE("GPL");
index a2978ab..a405155 100644 (file)
@@ -145,12 +145,12 @@ static void uniphier_serial_out(struct uart_port *p, int offset, int value)
  * The divisor latch register exists at different address.
  * Override dl_read/write callbacks.
  */
-static int uniphier_serial_dl_read(struct uart_8250_port *up)
+static u32 uniphier_serial_dl_read(struct uart_8250_port *up)
 {
        return readl(up->port.membase + UNIPHIER_UART_DLR);
 }
 
-static void uniphier_serial_dl_write(struct uart_8250_port *up, int value)
+static void uniphier_serial_dl_write(struct uart_8250_port *up, u32 value)
 {
        writel(value, up->port.membase + UNIPHIER_UART_DLR);
 }
index 5313aa3..ee17cf5 100644 (file)
@@ -71,14 +71,16 @@ config SERIAL_8250_16550A_VARIANTS
          console, you can say N here.
 
 config SERIAL_8250_FINTEK
-       bool "Support for Fintek F81216A LPC to 4 UART RS485 API"
+       bool "Support for Fintek variants"
        depends on SERIAL_8250
        help
-         Selecting this option will add support for the RS485 capabilities
-         of the Fintek F81216A LPC to 4 UART.
+         Selecting this option will add support for the RS232 and RS485
+         capabilities of the Fintek F81216A LPC to 4 UART as well similar
+         variants.
 
          If this option is not selected the device will be configured as a
-         standard 16550A serial port.
+         standard 16550A serial port, however the device may not function
+         correctly without this option enabled.
 
          If unsure, say N.
 
@@ -377,9 +379,9 @@ config SERIAL_8250_BCM2835AUX
          If unsure, say N.
 
 config SERIAL_8250_FSL
-       bool "Freescale 16550 UART support" if COMPILE_TEST && !(PPC || ARM || ARM64)
-       depends on SERIAL_8250_CONSOLE
-       default PPC || ARM || ARM64
+       tristate "Freescale 16550 UART support" if COMPILE_TEST && !(PPC || ARM || ARM64)
+       depends on SERIAL_8250
+       default SERIAL_8250 if PPC || ARM || ARM64
        help
          Selecting this option enables a workaround for a break-detection
          erratum for Freescale 16550 UARTs in the 8250 driver. It also
index 4fc2fc1..628b75b 100644 (file)
@@ -35,6 +35,7 @@ obj-$(CONFIG_SERIAL_8250_DW)          += 8250_dw.o
 obj-$(CONFIG_SERIAL_8250_EM)           += 8250_em.o
 obj-$(CONFIG_SERIAL_8250_IOC3)         += 8250_ioc3.o
 obj-$(CONFIG_SERIAL_8250_OMAP)         += 8250_omap.o
+obj-$(CONFIG_SERIAL_8250_RT288X)       += 8250_rt288x.o
 obj-$(CONFIG_SERIAL_8250_LPC18XX)      += 8250_lpc18xx.o
 obj-$(CONFIG_SERIAL_8250_MT6577)       += 8250_mtk.o
 obj-$(CONFIG_SERIAL_8250_UNIPHIER)     += 8250_uniphier.o
index 71a7a3e..bdc568a 100644 (file)
@@ -1555,6 +1555,29 @@ config SERIAL_SUNPLUS_CONSOLE
          you can alter that using a kernel command line option such as
          "console=ttySUPx".
 
+config SERIAL_NUVOTON_MA35D1
+       tristate "Nuvoton MA35D1 family UART support"
+       depends on ARCH_MA35 || COMPILE_TEST
+       select SERIAL_CORE
+       help
+         This driver supports Nuvoton MA35D1 family UART ports. If you would
+         like to use them, you must answer Y or M to this option. Note that
+         for use as console, it must be included in kernel and not as a
+         module. If you enable this option, Ma35D1 serial ports in the system
+         will be registered as ttyNVTx.
+
+config SERIAL_NUVOTON_MA35D1_CONSOLE
+       bool "Console on a Nuvotn MA35D1 family UART port"
+       depends on SERIAL_NUVOTON_MA35D1=y
+       select SERIAL_CORE_CONSOLE
+       help
+         Select this options if you'd like to use the UART port0 of the
+         Nuvoton MA35D1 family as a console.
+         Even if you say Y here, the currently visible virtual console
+         (/dev/tty0) will still be used as the system console by default,
+         but you can alter that using a kernel command line option such as
+         "console=ttyNVTx".
+
 endmenu
 
 config SERIAL_MCTRL_GPIO
index cd9afd9..d412346 100644 (file)
@@ -3,7 +3,8 @@
 # Makefile for the kernel serial device drivers.
 #
 
-obj-$(CONFIG_SERIAL_CORE) += serial_core.o
+obj-$(CONFIG_SERIAL_CORE) += serial_base.o
+serial_base-y := serial_core.o serial_base_bus.o serial_ctrl.o serial_port.o
 
 obj-$(CONFIG_SERIAL_EARLYCON) += earlycon.o
 obj-$(CONFIG_SERIAL_EARLYCON_SEMIHOST) += earlycon-semihost.o
@@ -21,7 +22,7 @@ obj-$(CONFIG_SERIAL_SUNSAB) += sunsab.o
 obj-$(CONFIG_SERIAL_21285) += 21285.o
 
 # Now bring in any enabled 8250/16450/16550 type drivers.
-obj-$(CONFIG_SERIAL_8250) += 8250/
+obj-y += 8250/
 
 obj-$(CONFIG_SERIAL_AMBA_PL010) += amba-pl010.o
 obj-$(CONFIG_SERIAL_AMBA_PL011) += amba-pl011.o
@@ -93,3 +94,4 @@ obj-$(CONFIG_SERIAL_MCTRL_GPIO)       += serial_mctrl_gpio.o
 
 obj-$(CONFIG_SERIAL_KGDB_NMI) += kgdb_nmi.o
 obj-$(CONFIG_KGDB_SERIAL_CONSOLE) += kgdboc.o
+obj-$(CONFIG_SERIAL_NUVOTON_MA35D1) += ma35d1_serial.o
index d8c2f34..c5c3f46 100644 (file)
@@ -2166,6 +2166,13 @@ pl011_set_termios(struct uart_port *port, struct ktermios *termios,
         * ----------^----------^----------^----------^-----
         */
        pl011_write_lcr_h(uap, lcr_h);
+
+       /*
+        * Receive was disabled by pl011_disable_uart during shutdown.
+        * Need to reenable receive if you need to use a tty_driver
+        * returns from tty_find_polling_driver() after a port shutdown.
+        */
+       old_cr |= UART011_CR_RXE;
        pl011_write(old_cr, uap, REG_CR);
 
        spin_unlock_irqrestore(&port->lock, flags);
index 9cd7479..3467a87 100644 (file)
@@ -868,11 +868,11 @@ static void atmel_complete_tx_dma(void *arg)
                dmaengine_terminate_all(chan);
        uart_xmit_advance(port, atmel_port->tx_len);
 
-       spin_lock_irq(&atmel_port->lock_tx);
+       spin_lock(&atmel_port->lock_tx);
        async_tx_ack(atmel_port->desc_tx);
        atmel_port->cookie_tx = -EINVAL;
        atmel_port->desc_tx = NULL;
-       spin_unlock_irq(&atmel_port->lock_tx);
+       spin_unlock(&atmel_port->lock_tx);
 
        if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
                uart_write_wakeup(port);
@@ -3006,14 +3006,13 @@ static int atmel_serial_remove(struct platform_device *pdev)
 {
        struct uart_port *port = platform_get_drvdata(pdev);
        struct atmel_uart_port *atmel_port = to_atmel_uart_port(port);
-       int ret = 0;
 
        tasklet_kill(&atmel_port->tasklet_rx);
        tasklet_kill(&atmel_port->tasklet_tx);
 
        device_init_wakeup(&pdev->dev, 0);
 
-       ret = uart_remove_one_port(&atmel_uart, port);
+       uart_remove_one_port(&atmel_uart, port);
 
        kfree(atmel_port->rx_ring.buf);
 
@@ -3023,7 +3022,7 @@ static int atmel_serial_remove(struct platform_device *pdev)
 
        pdev->dev.of_node = NULL;
 
-       return ret;
+       return 0;
 }
 
 static SIMPLE_DEV_PM_OPS(atmel_serial_pm_ops, atmel_serial_suspend,
index e190dce..e49bc40 100644 (file)
@@ -514,7 +514,9 @@ static int uart_clps711x_remove(struct platform_device *pdev)
 {
        struct clps711x_port *s = platform_get_drvdata(pdev);
 
-       return uart_remove_one_port(&clps711x_uart, &s->port);
+       uart_remove_one_port(&clps711x_uart, &s->port);
+
+       return 0;
 }
 
 static const struct of_device_id __maybe_unused clps711x_uart_dt_ids[] = {
index 349e7da..66afa9b 100644 (file)
@@ -1431,7 +1431,10 @@ static int cpm_uart_probe(struct platform_device *ofdev)
 static int cpm_uart_remove(struct platform_device *ofdev)
 {
        struct uart_cpm_port *pinfo = platform_get_drvdata(ofdev);
-       return uart_remove_one_port(&cpm_reg, &pinfo->port);
+
+       uart_remove_one_port(&cpm_reg, &pinfo->port);
+
+       return 0;
 }
 
 static const struct of_device_id cpm_uart_match[] = {
index 7fd30fc..4d80fae 100644 (file)
 
 /* Rx DMA timeout in ms, which is used to calculate Rx ring buffer size */
 #define DMA_RX_TIMEOUT         (10)
+#define DMA_RX_IDLE_CHARS      8
 #define UART_AUTOSUSPEND_TIMEOUT       3000
 
 #define DRIVER_NAME    "fsl-lpuart"
@@ -282,6 +283,7 @@ struct lpuart_port {
        struct scatterlist      rx_sgl, tx_sgl[2];
        struct circ_buf         rx_ring;
        int                     rx_dma_rng_buf_len;
+       int                     last_residue;
        unsigned int            dma_tx_nents;
        wait_queue_head_t       dma_wait;
        bool                    is_cs7; /* Set to true when character size is 7 */
@@ -331,7 +333,7 @@ static struct lpuart_soc_data imx8qxp_data = {
        .devtype = IMX8QXP_LPUART,
        .iotype = UPIO_MEM32,
        .reg_off = IMX_REG_OFF,
-       .rx_watermark = 31,
+       .rx_watermark = 7, /* A lower watermark is ideal for low baud rates. */
 };
 static struct lpuart_soc_data imxrt1050_data = {
        .devtype = IMXRT1050_LPUART,
@@ -1255,6 +1257,8 @@ static void lpuart_copy_rx_to_tty(struct lpuart_port *sport)
                sport->port.icount.rx += copied;
        }
 
+       sport->last_residue = state.residue;
+
 exit:
        dma_sync_sg_for_device(chan->device->dev, &sport->rx_sgl, 1,
                               DMA_FROM_DEVICE);
@@ -1272,11 +1276,43 @@ static void lpuart_dma_rx_complete(void *arg)
        lpuart_copy_rx_to_tty(sport);
 }
 
+/*
+ * Timer function to simulate the hardware EOP (End Of Package) event.
+ * The timer callback is to check for new RX data and copy to TTY buffer.
+ * If no new data are received since last interval, the EOP condition is
+ * met, complete the DMA transfer by copying the data. Otherwise, just
+ * restart timer.
+ */
 static void lpuart_timer_func(struct timer_list *t)
 {
        struct lpuart_port *sport = from_timer(sport, t, lpuart_timer);
+       enum dma_status dmastat;
+       struct dma_chan *chan = sport->dma_rx_chan;
+       struct circ_buf *ring = &sport->rx_ring;
+       struct dma_tx_state state;
+       unsigned long flags;
+       int count;
 
-       lpuart_copy_rx_to_tty(sport);
+       dmastat = dmaengine_tx_status(chan, sport->dma_rx_cookie, &state);
+       if (dmastat == DMA_ERROR) {
+               dev_err(sport->port.dev, "Rx DMA transfer failed!\n");
+               return;
+       }
+
+       ring->head = sport->rx_sgl.length - state.residue;
+       count = CIRC_CNT(ring->head, ring->tail, sport->rx_sgl.length);
+
+       /* Check if new data received before copying */
+       if ((count != 0) && (sport->last_residue == state.residue))
+               lpuart_copy_rx_to_tty(sport);
+       else
+               mod_timer(&sport->lpuart_timer,
+                         jiffies + sport->dma_rx_timeout);
+
+       if (spin_trylock_irqsave(&sport->port.lock, flags)) {
+               sport->last_residue = state.residue;
+               spin_unlock_irqrestore(&sport->port.lock, flags);
+       }
 }
 
 static inline int lpuart_start_rx_dma(struct lpuart_port *sport)
@@ -1297,9 +1333,20 @@ static inline int lpuart_start_rx_dma(struct lpuart_port *sport)
         */
        sport->rx_dma_rng_buf_len = (DMA_RX_TIMEOUT * baud /  bits / 1000) * 2;
        sport->rx_dma_rng_buf_len = (1 << fls(sport->rx_dma_rng_buf_len));
+       sport->rx_dma_rng_buf_len = max_t(int,
+                                         sport->rxfifo_size * 2,
+                                         sport->rx_dma_rng_buf_len);
+       /*
+        * Keep this condition check in case rxfifo_size is unavailable
+        * for some SoCs.
+        */
        if (sport->rx_dma_rng_buf_len < 16)
                sport->rx_dma_rng_buf_len = 16;
 
+       sport->last_residue = 0;
+       sport->dma_rx_timeout = max(nsecs_to_jiffies(
+               sport->port.frame_time * DMA_RX_IDLE_CHARS), 1UL);
+
        ring->buf = kzalloc(sport->rx_dma_rng_buf_len, GFP_ATOMIC);
        if (!ring->buf)
                return -ENOMEM;
@@ -1689,12 +1736,13 @@ static void lpuart_rx_dma_startup(struct lpuart_port *sport)
        if (!sport->dma_rx_chan)
                goto err;
 
+       /* set default Rx DMA timeout */
+       sport->dma_rx_timeout = msecs_to_jiffies(DMA_RX_TIMEOUT);
+
        ret = lpuart_start_rx_dma(sport);
        if (ret)
                goto err;
 
-       /* set Rx DMA timeout */
-       sport->dma_rx_timeout = msecs_to_jiffies(DMA_RX_TIMEOUT);
        if (!sport->dma_rx_timeout)
                sport->dma_rx_timeout = 1;
 
@@ -2676,6 +2724,7 @@ OF_EARLYCON_DECLARE(lpuart, "fsl,vf610-lpuart", lpuart_early_console_setup);
 OF_EARLYCON_DECLARE(lpuart32, "fsl,ls1021a-lpuart", lpuart32_early_console_setup);
 OF_EARLYCON_DECLARE(lpuart32, "fsl,ls1028a-lpuart", ls1028a_early_console_setup);
 OF_EARLYCON_DECLARE(lpuart32, "fsl,imx7ulp-lpuart", lpuart32_imx_early_console_setup);
+OF_EARLYCON_DECLARE(lpuart32, "fsl,imx8ulp-lpuart", lpuart32_imx_early_console_setup);
 OF_EARLYCON_DECLARE(lpuart32, "fsl,imx8qxp-lpuart", lpuart32_imx_early_console_setup);
 OF_EARLYCON_DECLARE(lpuart32, "fsl,imxrt1050-lpuart", lpuart32_imx_early_console_setup);
 EARLYCON_DECLARE(lpuart, lpuart_early_console_setup);
index c5e1756..7341d06 100644 (file)
@@ -369,6 +369,16 @@ static void imx_uart_soft_reset(struct imx_port *sport)
        sport->idle_counter = 0;
 }
 
+static void imx_uart_disable_loopback_rs485(struct imx_port *sport)
+{
+       unsigned int uts;
+
+       /* See SER_RS485_ENABLED/UTS_LOOP comment in imx_uart_probe() */
+       uts = imx_uart_readl(sport, imx_uart_uts_reg(sport));
+       uts &= ~UTS_LOOP;
+       imx_uart_writel(sport, uts, imx_uart_uts_reg(sport));
+}
+
 /* called with port.lock taken and irqs off */
 static void imx_uart_start_rx(struct uart_port *port)
 {
@@ -390,6 +400,7 @@ static void imx_uart_start_rx(struct uart_port *port)
        /* Write UCR2 first as it includes RXEN */
        imx_uart_writel(sport, ucr2, UCR2);
        imx_uart_writel(sport, ucr1, UCR1);
+       imx_uart_disable_loopback_rs485(sport);
 }
 
 /* called with port.lock taken and irqs off */
@@ -1422,7 +1433,7 @@ static int imx_uart_startup(struct uart_port *port)
        int retval;
        unsigned long flags;
        int dma_is_inited = 0;
-       u32 ucr1, ucr2, ucr3, ucr4, uts;
+       u32 ucr1, ucr2, ucr3, ucr4;
 
        retval = clk_prepare_enable(sport->clk_per);
        if (retval)
@@ -1521,10 +1532,7 @@ static int imx_uart_startup(struct uart_port *port)
                imx_uart_writel(sport, ucr2, UCR2);
        }
 
-       /* See SER_RS485_ENABLED/UTS_LOOP comment in imx_uart_probe() */
-       uts = imx_uart_readl(sport, imx_uart_uts_reg(sport));
-       uts &= ~UTS_LOOP;
-       imx_uart_writel(sport, uts, imx_uart_uts_reg(sport));
+       imx_uart_disable_loopback_rs485(sport);
 
        spin_unlock_irqrestore(&sport->port.lock, flags);
 
@@ -2467,7 +2475,9 @@ static int imx_uart_remove(struct platform_device *pdev)
 {
        struct imx_port *sport = platform_get_drvdata(pdev);
 
-       return uart_remove_one_port(&imx_uart_uart_driver, &sport->port);
+       uart_remove_one_port(&imx_uart_uart_driver, &sport->port);
+
+       return 0;
 }
 
 static void imx_uart_restore_context(struct imx_port *sport)
index f1387f1..bcaa479 100644 (file)
@@ -890,7 +890,9 @@ static int lqasc_remove(struct platform_device *pdev)
 {
        struct uart_port *port = platform_get_drvdata(pdev);
 
-       return uart_remove_one_port(&lqasc_reg, port);
+       uart_remove_one_port(&lqasc_reg, port);
+
+       return 0;
 }
 
 static const struct ltq_soc_data soc_data_lantiq = {
diff --git a/drivers/tty/serial/ma35d1_serial.c b/drivers/tty/serial/ma35d1_serial.c
new file mode 100644 (file)
index 0000000..2604b4d
--- /dev/null
@@ -0,0 +1,821 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ *  MA35D1 serial driver
+ *  Copyright (C) 2023 Nuvoton Technology Corp.
+ */
+
+#include <linux/bitfield.h>
+#include <linux/clk.h>
+#include <linux/delay.h>
+#include <linux/of.h>
+#include <linux/of_platform.h>
+#include <linux/iopoll.h>
+#include <linux/serial_core.h>
+#include <linux/slab.h>
+#include <linux/tty_flip.h>
+#include <linux/units.h>
+
+#define MA35_UART_NR           17
+
+#define MA35_RBR_REG           0x00
+#define MA35_THR_REG           0x00
+#define MA35_IER_REG           0x04
+#define MA35_FCR_REG           0x08
+#define MA35_LCR_REG           0x0C
+#define MA35_MCR_REG           0x10
+#define MA35_MSR_REG           0x14
+#define MA35_FSR_REG           0x18
+#define MA35_ISR_REG           0x1C
+#define MA35_TOR_REG           0x20
+#define MA35_BAUD_REG          0x24
+#define MA35_ALTCTL_REG                0x2C
+#define MA35_FUN_SEL_REG       0x30
+#define MA35_WKCTL_REG         0x40
+#define MA35_WKSTS_REG         0x44
+
+/* MA35_IER_REG - Interrupt Enable Register */
+#define MA35_IER_RDA_IEN       BIT(0)  /* RBR Available Interrupt Enable */
+#define MA35_IER_THRE_IEN      BIT(1)  /* THR Empty Interrupt Enable */
+#define MA35_IER_RLS_IEN       BIT(2)  /* RX Line Status Interrupt Enable */
+#define MA35_IER_RTO_IEN       BIT(4)  /* RX Time-out Interrupt Enable */
+#define MA35_IER_BUFERR_IEN    BIT(5)  /* Buffer Error Interrupt Enable */
+#define MA35_IER_TIME_OUT_EN   BIT(11) /* RX Buffer Time-out Counter Enable */
+#define MA35_IER_AUTO_RTS      BIT(12) /* nRTS Auto-flow Control Enable */
+#define MA35_IER_AUTO_CTS      BIT(13) /* nCTS Auto-flow Control Enable */
+
+/* MA35_FCR_REG - FIFO Control Register */
+#define MA35_FCR_RFR           BIT(1)  /* RX Field Software Reset */
+#define MA35_FCR_TFR           BIT(2)  /* TX Field Software Reset */
+#define MA35_FCR_RFITL_MASK    GENMASK(7, 4) /* RX FIFO Interrupt Trigger Level */
+#define MA35_FCR_RFITL_1BYTE   FIELD_PREP(MA35_FCR_RFITL_MASK, 0)
+#define MA35_FCR_RFITL_4BYTES  FIELD_PREP(MA35_FCR_RFITL_MASK, 1)
+#define MA35_FCR_RFITL_8BYTES  FIELD_PREP(MA35_FCR_RFITL_MASK, 2)
+#define MA35_FCR_RFITL_14BYTES FIELD_PREP(MA35_FCR_RFITL_MASK, 3)
+#define MA35_FCR_RFITL_30BYTES FIELD_PREP(MA35_FCR_RFITL_MASK, 4)
+#define MA35_FCR_RTSTL_MASK    GENMASK(19, 16) /* nRTS Trigger Level */
+#define MA35_FCR_RTSTL_1BYTE   FIELD_PREP(MA35_FCR_RTSTL_MASK, 0)
+#define MA35_FCR_RTSTL_4BYTES  FIELD_PREP(MA35_FCR_RTSTL_MASK, 1)
+#define MA35_FCR_RTSTL_8BYTES  FIELD_PREP(MA35_FCR_RTSTL_MASK, 2)
+#define MA35_FCR_RTSTL_14BYTES FIELD_PREP(MA35_FCR_RTSTL_MASK, 3)
+#define MA35_FCR_RTSTLL_30BYTES        FIELD_PREP(MA35_FCR_RTSTL_MASK, 4)
+
+/* MA35_LCR_REG - Line Control Register */
+#define        MA35_LCR_NSB            BIT(2)  /* Number of “STOP Bit” */
+#define MA35_LCR_PBE           BIT(3)  /* Parity Bit Enable */
+#define MA35_LCR_EPE           BIT(4)  /* Even Parity Enable */
+#define MA35_LCR_SPE           BIT(5)  /* Stick Parity Enable */
+#define MA35_LCR_BREAK         BIT(6)  /* Break Control */
+#define MA35_LCR_WLS_MASK      GENMASK(1, 0) /* Word Length Selection */
+#define MA35_LCR_WLS_5BITS     FIELD_PREP(MA35_LCR_WLS_MASK, 0)
+#define MA35_LCR_WLS_6BITS     FIELD_PREP(MA35_LCR_WLS_MASK, 1)
+#define MA35_LCR_WLS_7BITS     FIELD_PREP(MA35_LCR_WLS_MASK, 2)
+#define MA35_LCR_WLS_8BITS     FIELD_PREP(MA35_LCR_WLS_MASK, 3)
+
+/* MA35_MCR_REG - Modem Control Register */
+#define MA35_MCR_RTS_CTRL      BIT(1)  /* nRTS Signal Control */
+#define MA35_MCR_RTSACTLV      BIT(9)  /* nRTS Pin Active Level */
+#define MA35_MCR_RTSSTS                BIT(13) /* nRTS Pin Status (Read Only) */
+
+/* MA35_MSR_REG - Modem Status Register */
+#define MA35_MSR_CTSDETF       BIT(0)  /* Detect nCTS State Change Flag */
+#define MA35_MSR_CTSSTS                BIT(4)  /* nCTS Pin Status (Read Only) */
+#define MA35_MSR_CTSACTLV      BIT(8)  /* nCTS Pin Active Level */
+
+/* MA35_FSR_REG - FIFO Status Register */
+#define MA35_FSR_RX_OVER_IF    BIT(0)  /* RX Overflow Error Interrupt Flag */
+#define MA35_FSR_PEF           BIT(4)  /* Parity Error Flag*/
+#define MA35_FSR_FEF           BIT(5)  /* Framing Error Flag */
+#define MA35_FSR_BIF           BIT(6)  /* Break Interrupt Flag */
+#define MA35_FSR_RX_EMPTY      BIT(14) /* Receiver FIFO Empty (Read Only) */
+#define MA35_FSR_RX_FULL       BIT(15) /* Receiver FIFO Full (Read Only) */
+#define MA35_FSR_TX_EMPTY      BIT(22) /* Transmitter FIFO Empty (Read Only) */
+#define MA35_FSR_TX_FULL       BIT(23) /* Transmitter FIFO Full (Read Only) */
+#define MA35_FSR_TX_OVER_IF    BIT(24) /* TX Overflow Error Interrupt Flag */
+#define MA35_FSR_TE_FLAG       BIT(28) /* Transmitter Empty Flag (Read Only) */
+#define MA35_FSR_RXPTR_MSK     GENMASK(13, 8) /* TX FIFO Pointer mask */
+#define MA35_FSR_TXPTR_MSK     GENMASK(21, 16) /* RX FIFO Pointer mask */
+
+/* MA35_ISR_REG - Interrupt Status Register */
+#define MA35_ISR_RDA_IF                BIT(0)  /* RBR Available Interrupt Flag */
+#define MA35_ISR_THRE_IF       BIT(1)  /* THR Empty Interrupt Flag */
+#define MA35_ISR_RLSIF         BIT(2)  /* Receive Line Interrupt Flag */
+#define MA35_ISR_MODEMIF       BIT(3)  /* MODEM Interrupt Flag */
+#define MA35_ISR_RXTO_IF       BIT(4)  /* RX Time-out Interrupt Flag */
+#define MA35_ISR_BUFEIF                BIT(5)  /* Buffer Error Interrupt Flag */
+#define MA35_ISR_WK_IF         BIT(6)  /* UART Wake-up Interrupt Flag */
+#define MA35_ISR_RDAINT                BIT(8)  /* RBR Available Interrupt Indicator */
+#define MA35_ISR_THRE_INT      BIT(9)  /* THR Empty Interrupt Indicator */
+#define MA35_ISR_ALL           0xFFFFFFFF
+
+/* MA35_BAUD_REG - Baud Rate Divider Register */
+#define        MA35_BAUD_MODE_MASK     GENMASK(29, 28)
+#define MA35_BAUD_MODE0                FIELD_PREP(MA35_BAUD_MODE_MASK, 0)
+#define MA35_BAUD_MODE1                FIELD_PREP(MA35_BAUD_MODE_MASK, 2)
+#define MA35_BAUD_MODE2                FIELD_PREP(MA35_BAUD_MODE_MASK, 3)
+#define        MA35_BAUD_MASK          GENMASK(15, 0)
+
+/* MA35_ALTCTL_REG - Alternate Control/Status Register */
+#define MA35_ALTCTL_RS485AUD   BIT(10) /* RS-485 Auto Direction Function */
+
+/* MA35_FUN_SEL_REG - Function Select Register */
+#define MA35_FUN_SEL_MASK      GENMASK(2, 0)
+#define MA35_FUN_SEL_UART      FIELD_PREP(MA35_FUN_SEL_MASK, 0)
+#define MA35_FUN_SEL_RS485     FIELD_PREP(MA35_FUN_SEL_MASK, 3)
+
+/* The constrain for MA35D1 UART baud rate divider */
+#define MA35_BAUD_DIV_MAX      0xFFFF
+#define MA35_BAUD_DIV_MIN      11
+
+/* UART FIFO depth */
+#define MA35_UART_FIFO_DEPTH   32
+/* UART console clock */
+#define MA35_UART_CONSOLE_CLK  (24 * HZ_PER_MHZ)
+/* UART register ioremap size */
+#define MA35_UART_REG_SIZE     0x100
+/* Rx Timeout */
+#define MA35_UART_RX_TOUT      0x40
+
+#define MA35_IER_CONFIG                (MA35_IER_RTO_IEN | MA35_IER_RDA_IEN | \
+                                MA35_IER_TIME_OUT_EN | MA35_IER_BUFERR_IEN)
+
+#define MA35_ISR_IF_CHECK      (MA35_ISR_RDA_IF | MA35_ISR_RXTO_IF | \
+                                MA35_ISR_THRE_INT | MA35_ISR_BUFEIF)
+
+#define MA35_FSR_TX_BOTH_EMPTY (MA35_FSR_TE_FLAG | MA35_FSR_TX_EMPTY)
+
+static struct uart_driver ma35d1serial_reg;
+
+struct uart_ma35d1_port {
+       struct uart_port port;
+       struct clk *clk;
+       u16 capabilities; /* port capabilities */
+       u8 ier;
+       u8 lcr;
+       u8 mcr;
+       u32 baud_rate;
+       u32 console_baud_rate;
+       u32 console_line;
+       u32 console_int;
+};
+
+static struct uart_ma35d1_port ma35d1serial_ports[MA35_UART_NR];
+
+static struct uart_ma35d1_port *to_ma35d1_uart_port(struct uart_port *uart)
+{
+       return container_of(uart, struct uart_ma35d1_port, port);
+}
+
+static u32 serial_in(struct uart_ma35d1_port *p, u32 offset)
+{
+       return readl_relaxed(p->port.membase + offset);
+}
+
+static void serial_out(struct uart_ma35d1_port *p, u32 offset, u32 value)
+{
+       writel_relaxed(value, p->port.membase + offset);
+}
+
+static void __stop_tx(struct uart_ma35d1_port *p)
+{
+       u32 ier;
+
+       ier = serial_in(p, MA35_IER_REG);
+       if (ier & MA35_IER_THRE_IEN)
+               serial_out(p, MA35_IER_REG, ier & ~MA35_IER_THRE_IEN);
+}
+
+static void ma35d1serial_stop_tx(struct uart_port *port)
+{
+       struct uart_ma35d1_port *up = to_ma35d1_uart_port(port);
+
+       __stop_tx(up);
+}
+
+static void transmit_chars(struct uart_ma35d1_port *up)
+{
+       u32 count;
+       u8 ch;
+
+       if (uart_tx_stopped(&up->port)) {
+               ma35d1serial_stop_tx(&up->port);
+               return;
+       }
+       count = MA35_UART_FIFO_DEPTH - FIELD_GET(MA35_FSR_TXPTR_MSK,
+                                                serial_in(up, MA35_FSR_REG));
+       uart_port_tx_limited(&up->port, ch, count,
+                            !(serial_in(up, MA35_FSR_REG) & MA35_FSR_TX_FULL),
+                            serial_out(up, MA35_THR_REG, ch),
+                            ({}));
+}
+
+static void ma35d1serial_start_tx(struct uart_port *port)
+{
+       struct uart_ma35d1_port *up = to_ma35d1_uart_port(port);
+       u32 ier;
+
+       ier = serial_in(up, MA35_IER_REG);
+       serial_out(up, MA35_IER_REG, ier & ~MA35_IER_THRE_IEN);
+       transmit_chars(up);
+       serial_out(up, MA35_IER_REG, ier | MA35_IER_THRE_IEN);
+}
+
+static void ma35d1serial_stop_rx(struct uart_port *port)
+{
+       struct uart_ma35d1_port *up = to_ma35d1_uart_port(port);
+       u32 ier;
+
+       ier = serial_in(up, MA35_IER_REG);
+       ier &= ~MA35_IER_RDA_IEN;
+       serial_out(up, MA35_IER_REG, ier);
+}
+
+static void receive_chars(struct uart_ma35d1_port *up)
+{
+       int max_count = 256;
+       u8 ch, flag;
+       u32 fsr;
+
+       fsr = serial_in(up, MA35_FSR_REG);
+       do {
+               flag = TTY_NORMAL;
+               up->port.icount.rx++;
+
+               if (unlikely(fsr & (MA35_FSR_BIF | MA35_FSR_FEF |
+                                   MA35_FSR_PEF | MA35_FSR_RX_OVER_IF))) {
+                       if (fsr & MA35_FSR_BIF) {
+                               up->port.icount.brk++;
+                               if (uart_handle_break(&up->port))
+                                       continue;
+                       }
+                       if (fsr & MA35_FSR_FEF)
+                               up->port.icount.frame++;
+                       if (fsr & MA35_FSR_PEF)
+                               up->port.icount.parity++;
+                       if (fsr & MA35_FSR_RX_OVER_IF)
+                               up->port.icount.overrun++;
+
+                       serial_out(up, MA35_FSR_REG,
+                                  fsr & (MA35_FSR_BIF | MA35_FSR_FEF |
+                                         MA35_FSR_PEF | MA35_FSR_RX_OVER_IF));
+                       if (fsr & MA35_FSR_BIF)
+                               flag = TTY_BREAK;
+                       else if (fsr & MA35_FSR_PEF)
+                               flag = TTY_PARITY;
+                       else if (fsr & MA35_FSR_FEF)
+                               flag = TTY_FRAME;
+               }
+
+               ch = serial_in(up, MA35_RBR_REG);
+               if (uart_handle_sysrq_char(&up->port, ch))
+                       continue;
+
+               spin_lock(&up->port.lock);
+               uart_insert_char(&up->port, fsr, MA35_FSR_RX_OVER_IF, ch, flag);
+               spin_unlock(&up->port.lock);
+
+               fsr = serial_in(up, MA35_FSR_REG);
+       } while (!(fsr & MA35_FSR_RX_EMPTY) && (max_count-- > 0));
+
+       spin_lock(&up->port.lock);
+       tty_flip_buffer_push(&up->port.state->port);
+       spin_unlock(&up->port.lock);
+}
+
+static irqreturn_t ma35d1serial_interrupt(int irq, void *dev_id)
+{
+       struct uart_port *port = dev_id;
+       struct uart_ma35d1_port *up = to_ma35d1_uart_port(port);
+       u32 isr, fsr;
+
+       isr = serial_in(up, MA35_ISR_REG);
+       fsr = serial_in(up, MA35_FSR_REG);
+
+       if (!(isr & MA35_ISR_IF_CHECK))
+               return IRQ_NONE;
+
+       if (isr & (MA35_ISR_RDA_IF | MA35_ISR_RXTO_IF))
+               receive_chars(up);
+       if (isr & MA35_ISR_THRE_INT)
+               transmit_chars(up);
+       if (fsr & MA35_FSR_TX_OVER_IF)
+               serial_out(up, MA35_FSR_REG, MA35_FSR_TX_OVER_IF);
+
+       return IRQ_HANDLED;
+}
+
+static u32 ma35d1serial_tx_empty(struct uart_port *port)
+{
+       struct uart_ma35d1_port *up = to_ma35d1_uart_port(port);
+       u32 fsr;
+
+       fsr = serial_in(up, MA35_FSR_REG);
+       if ((fsr & MA35_FSR_TX_BOTH_EMPTY) == MA35_FSR_TX_BOTH_EMPTY)
+               return TIOCSER_TEMT;
+       else
+               return 0;
+}
+
+static u32 ma35d1serial_get_mctrl(struct uart_port *port)
+{
+       struct uart_ma35d1_port *up = to_ma35d1_uart_port(port);
+       u32 status;
+       u32 ret = 0;
+
+       status = serial_in(up, MA35_MSR_REG);
+       if (!(status & MA35_MSR_CTSSTS))
+               ret |= TIOCM_CTS;
+       return ret;
+}
+
+static void ma35d1serial_set_mctrl(struct uart_port *port, u32 mctrl)
+{
+       struct uart_ma35d1_port *up = to_ma35d1_uart_port(port);
+       u32 mcr, msr, ier;
+
+       mcr = serial_in(up, MA35_MCR_REG);
+       mcr &= ~MA35_MCR_RTS_CTRL;
+
+       if (mctrl & TIOCM_RTS)
+               mcr |= MA35_MCR_RTSACTLV;
+       else
+               mcr &= ~MA35_MCR_RTSACTLV;
+
+       if (up->mcr & UART_MCR_AFE) {
+               ier = serial_in(up, MA35_IER_REG);
+               ier |= MA35_IER_AUTO_RTS | MA35_IER_AUTO_CTS;
+               serial_out(up, MA35_IER_REG, ier);
+               up->port.flags |= UPF_HARD_FLOW;
+       } else {
+               ier = serial_in(up, MA35_IER_REG);
+               ier &= ~(MA35_IER_AUTO_RTS | MA35_IER_AUTO_CTS);
+               serial_out(up, MA35_IER_REG, ier);
+               up->port.flags &= ~UPF_HARD_FLOW;
+       }
+
+       msr = serial_in(up, MA35_MSR_REG);
+       msr |= MA35_MSR_CTSACTLV;
+       serial_out(up, MA35_MSR_REG, msr);
+       serial_out(up, MA35_MCR_REG, mcr);
+}
+
+static void ma35d1serial_break_ctl(struct uart_port *port, int break_state)
+{
+       struct uart_ma35d1_port *up = to_ma35d1_uart_port(port);
+       unsigned long flags;
+       u32 lcr;
+
+       spin_lock_irqsave(&up->port.lock, flags);
+       lcr = serial_in(up, MA35_LCR_REG);
+       if (break_state != 0)
+               lcr |= MA35_LCR_BREAK;
+       else
+               lcr &= ~MA35_LCR_BREAK;
+       serial_out(up, MA35_LCR_REG, lcr);
+       spin_unlock_irqrestore(&up->port.lock, flags);
+}
+
+static int ma35d1serial_startup(struct uart_port *port)
+{
+       struct uart_ma35d1_port *up = to_ma35d1_uart_port(port);
+       u32 fcr;
+       int retval;
+
+       /* Reset FIFO */
+       serial_out(up, MA35_FCR_REG, MA35_FCR_TFR | MA35_FCR_RFR);
+
+       /* Clear pending interrupts */
+       serial_out(up, MA35_ISR_REG, MA35_ISR_ALL);
+
+       retval = request_irq(port->irq, ma35d1serial_interrupt, 0,
+                            dev_name(port->dev), port);
+       if (retval) {
+               dev_err(up->port.dev, "request irq failed.\n");
+               return retval;
+       }
+
+       fcr = serial_in(up, MA35_FCR_REG);
+       fcr |= MA35_FCR_RFITL_4BYTES | MA35_FCR_RTSTL_8BYTES;
+       serial_out(up, MA35_FCR_REG, fcr);
+       serial_out(up, MA35_LCR_REG, MA35_LCR_WLS_8BITS);
+       serial_out(up, MA35_TOR_REG, MA35_UART_RX_TOUT);
+       serial_out(up, MA35_IER_REG, MA35_IER_CONFIG);
+       return 0;
+}
+
+static void ma35d1serial_shutdown(struct uart_port *port)
+{
+       struct uart_ma35d1_port *up = to_ma35d1_uart_port(port);
+
+       serial_out(up, MA35_IER_REG, 0);
+       free_irq(port->irq, port);
+}
+
+static void ma35d1serial_set_termios(struct uart_port *port,
+                                    struct ktermios *termios,
+                                    const struct ktermios *old)
+{
+       struct uart_ma35d1_port *up = to_ma35d1_uart_port(port);
+       unsigned long flags;
+       u32 baud, quot;
+       u32 lcr = 0;
+
+       lcr = UART_LCR_WLEN(tty_get_char_size(termios->c_cflag));
+
+       if (termios->c_cflag & CSTOPB)
+               lcr |= MA35_LCR_NSB;
+       if (termios->c_cflag & PARENB)
+               lcr |= MA35_LCR_PBE;
+       if (!(termios->c_cflag & PARODD))
+               lcr |= MA35_LCR_EPE;
+       if (termios->c_cflag & CMSPAR)
+               lcr |= MA35_LCR_SPE;
+
+       baud = uart_get_baud_rate(port, termios, old,
+                                 port->uartclk / MA35_BAUD_DIV_MAX,
+                                 port->uartclk / MA35_BAUD_DIV_MIN);
+
+       /* MA35D1 UART baud rate equation: baudrate = UART_CLK / (quot + 2) */
+       quot = (port->uartclk / baud) - 2;
+
+       /*
+        * Ok, we're now changing the port state.  Do it with
+        * interrupts disabled.
+        */
+       spin_lock_irqsave(&up->port.lock, flags);
+
+       up->port.read_status_mask = MA35_FSR_RX_OVER_IF;
+       if (termios->c_iflag & INPCK)
+               up->port.read_status_mask |= MA35_FSR_FEF | MA35_FSR_PEF;
+       if (termios->c_iflag & (BRKINT | PARMRK))
+               up->port.read_status_mask |= MA35_FSR_BIF;
+
+       /* Characteres to ignore */
+       up->port.ignore_status_mask = 0;
+       if (termios->c_iflag & IGNPAR)
+               up->port.ignore_status_mask |= MA35_FSR_FEF | MA35_FSR_PEF;
+       if (termios->c_iflag & IGNBRK) {
+               up->port.ignore_status_mask |= MA35_FSR_BIF;
+               /*
+                * If we're ignoring parity and break indicators,
+                * ignore overruns too (for real raw support).
+                */
+               if (termios->c_iflag & IGNPAR)
+                       up->port.ignore_status_mask |= MA35_FSR_RX_OVER_IF;
+       }
+       if (termios->c_cflag & CRTSCTS)
+               up->mcr |= UART_MCR_AFE;
+       else
+               up->mcr &= ~UART_MCR_AFE;
+
+       uart_update_timeout(port, termios->c_cflag, baud);
+
+       ma35d1serial_set_mctrl(&up->port, up->port.mctrl);
+
+       serial_out(up, MA35_BAUD_REG, MA35_BAUD_MODE2 | FIELD_PREP(MA35_BAUD_MASK, quot));
+
+       serial_out(up, MA35_LCR_REG, lcr);
+
+       spin_unlock_irqrestore(&up->port.lock, flags);
+}
+
+static const char *ma35d1serial_type(struct uart_port *port)
+{
+       return "ma35d1-uart";
+}
+
+static void ma35d1serial_config_port(struct uart_port *port, int flags)
+{
+       /*
+        * Driver core for serial ports forces a non-zero value for port type.
+        * Write an arbitrary value here to accommodate the serial core driver,
+        * as ID part of UAPI is redundant.
+        */
+       port->type = 1;
+}
+
+static int ma35d1serial_verify_port(struct uart_port *port, struct serial_struct *ser)
+{
+       if (port->type != PORT_UNKNOWN && ser->type != 1)
+               return -EINVAL;
+
+       return 0;
+}
+
+static const struct uart_ops ma35d1serial_ops = {
+       .tx_empty     = ma35d1serial_tx_empty,
+       .set_mctrl    = ma35d1serial_set_mctrl,
+       .get_mctrl    = ma35d1serial_get_mctrl,
+       .stop_tx      = ma35d1serial_stop_tx,
+       .start_tx     = ma35d1serial_start_tx,
+       .stop_rx      = ma35d1serial_stop_rx,
+       .break_ctl    = ma35d1serial_break_ctl,
+       .startup      = ma35d1serial_startup,
+       .shutdown     = ma35d1serial_shutdown,
+       .set_termios  = ma35d1serial_set_termios,
+       .type         = ma35d1serial_type,
+       .config_port  = ma35d1serial_config_port,
+       .verify_port  = ma35d1serial_verify_port,
+};
+
+static const struct of_device_id ma35d1_serial_of_match[] = {
+       { .compatible = "nuvoton,ma35d1-uart" },
+       {},
+};
+MODULE_DEVICE_TABLE(of, ma35d1_serial_of_match);
+
+#ifdef CONFIG_SERIAL_NUVOTON_MA35D1_CONSOLE
+
+static struct device_node *ma35d1serial_uart_nodes[MA35_UART_NR];
+
+static void wait_for_xmitr(struct uart_ma35d1_port *up)
+{
+       unsigned int reg = 0;
+
+       read_poll_timeout_atomic(serial_in, reg, reg & MA35_FSR_TX_EMPTY,
+                                1, 10000, false,
+                                up, MA35_FSR_REG);
+}
+
+static void ma35d1serial_console_putchar(struct uart_port *port, unsigned char ch)
+{
+       struct uart_ma35d1_port *up = to_ma35d1_uart_port(port);
+
+       wait_for_xmitr(up);
+       serial_out(up, MA35_THR_REG, ch);
+}
+
+/*
+ *  Print a string to the serial port trying not to disturb
+ *  any possible real use of the port...
+ *
+ *  The console_lock must be held when we get here.
+ */
+static void ma35d1serial_console_write(struct console *co, const char *s, u32 count)
+{
+       struct uart_ma35d1_port *up = &ma35d1serial_ports[co->index];
+       unsigned long flags;
+       int locked = 1;
+       u32 ier;
+
+       if (up->port.sysrq)
+               locked = 0;
+       else if (oops_in_progress)
+               locked = spin_trylock_irqsave(&up->port.lock, flags);
+       else
+               spin_lock_irqsave(&up->port.lock, flags);
+
+       /*
+        *  First save the IER then disable the interrupts
+        */
+       ier = serial_in(up, MA35_IER_REG);
+       serial_out(up, MA35_IER_REG, 0);
+
+       uart_console_write(&up->port, s, count, ma35d1serial_console_putchar);
+
+       wait_for_xmitr(up);
+       serial_out(up, MA35_IER_REG, ier);
+
+       if (locked)
+               spin_unlock_irqrestore(&up->port.lock, flags);
+}
+
+static int __init ma35d1serial_console_setup(struct console *co, char *options)
+{
+       struct device_node *np;
+       struct uart_ma35d1_port *p;
+       u32 val32[4];
+       struct uart_port *port;
+       int baud = 115200;
+       int bits = 8;
+       int parity = 'n';
+       int flow = 'n';
+
+       if ((co->index < 0) || (co->index >= MA35_UART_NR)) {
+               pr_debug("Console Port%x out of range\n", co->index);
+               return -EINVAL;
+       }
+
+       np = ma35d1serial_uart_nodes[co->index];
+       p = &ma35d1serial_ports[co->index];
+       if (!np || !p)
+               return -ENODEV;
+
+       if (of_property_read_u32_array(np, "reg", val32, ARRAY_SIZE(val32)) != 0)
+               return -EINVAL;
+
+       p->port.iobase = val32[1];
+       p->port.membase = ioremap(p->port.iobase, MA35_UART_REG_SIZE);
+       if (!p->port.membase)
+               return -ENOMEM;
+
+       p->port.ops = &ma35d1serial_ops;
+       p->port.line = 0;
+       p->port.uartclk = MA35_UART_CONSOLE_CLK;
+
+       port = &ma35d1serial_ports[co->index].port;
+
+       if (options)
+               uart_parse_options(options, &baud, &parity, &bits, &flow);
+
+       return uart_set_options(port, co, baud, parity, bits, flow);
+}
+
+static struct console ma35d1serial_console = {
+       .name    = "ttyNVT",
+       .write   = ma35d1serial_console_write,
+       .device  = uart_console_device,
+       .setup   = ma35d1serial_console_setup,
+       .flags   = CON_PRINTBUFFER | CON_ENABLED,
+       .index   = -1,
+       .data    = &ma35d1serial_reg,
+};
+
+static void ma35d1serial_console_init_port(void)
+{
+       u32 i = 0;
+       struct device_node *np;
+
+       for_each_matching_node(np, ma35d1_serial_of_match) {
+               if (ma35d1serial_uart_nodes[i] == NULL) {
+                       of_node_get(np);
+                       ma35d1serial_uart_nodes[i] = np;
+                       i++;
+                       if (i == MA35_UART_NR)
+                               break;
+               }
+       }
+}
+
+static int __init ma35d1serial_console_init(void)
+{
+       ma35d1serial_console_init_port();
+       register_console(&ma35d1serial_console);
+       return 0;
+}
+console_initcall(ma35d1serial_console_init);
+
+#define MA35D1SERIAL_CONSOLE    (&ma35d1serial_console)
+#else
+#define MA35D1SERIAL_CONSOLE    NULL
+#endif
+
+static struct uart_driver ma35d1serial_reg = {
+       .owner        = THIS_MODULE,
+       .driver_name  = "serial",
+       .dev_name     = "ttyNVT",
+       .major        = TTY_MAJOR,
+       .minor        = 64,
+       .cons         = MA35D1SERIAL_CONSOLE,
+       .nr           = MA35_UART_NR,
+};
+
+/*
+ * Register a set of serial devices attached to a platform device.
+ * The list is terminated with a zero flags entry, which means we expect
+ * all entries to have at least UPF_BOOT_AUTOCONF set.
+ */
+static int ma35d1serial_probe(struct platform_device *pdev)
+{
+       struct resource *res_mem;
+       struct uart_ma35d1_port *up;
+       int ret = 0;
+
+       if (pdev->dev.of_node) {
+               ret = of_alias_get_id(pdev->dev.of_node, "serial");
+               if (ret < 0) {
+                       dev_err(&pdev->dev, "failed to get alias/pdev id, errno %d\n", ret);
+                       return ret;
+               }
+       }
+       up = &ma35d1serial_ports[ret];
+       up->port.line = ret;
+       res_mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+       if (!res_mem)
+               return -ENODEV;
+
+       up->port.iobase = res_mem->start;
+       up->port.membase = ioremap(up->port.iobase, MA35_UART_REG_SIZE);
+       up->port.ops = &ma35d1serial_ops;
+
+       spin_lock_init(&up->port.lock);
+
+       up->clk = of_clk_get(pdev->dev.of_node, 0);
+       if (IS_ERR(up->clk)) {
+               ret = PTR_ERR(up->clk);
+               dev_err(&pdev->dev, "failed to get core clk: %d\n", ret);
+               goto err_iounmap;
+       }
+
+       ret = clk_prepare_enable(up->clk);
+       if (ret)
+               goto err_iounmap;
+
+       if (up->port.line != 0)
+               up->port.uartclk = clk_get_rate(up->clk);
+
+       ret = platform_get_irq(pdev, 0);
+       if (ret < 0)
+               goto err_clk_disable;
+
+       up->port.irq = ret;
+       up->port.dev = &pdev->dev;
+       up->port.flags = UPF_BOOT_AUTOCONF;
+
+       platform_set_drvdata(pdev, up);
+
+       ret = uart_add_one_port(&ma35d1serial_reg, &up->port);
+       if (ret < 0)
+               goto err_free_irq;
+
+       return 0;
+
+err_free_irq:
+       free_irq(up->port.irq, &up->port);
+
+err_clk_disable:
+       clk_disable_unprepare(up->clk);
+
+err_iounmap:
+       iounmap(up->port.membase);
+       return ret;
+}
+
+/*
+ * Remove serial ports registered against a platform device.
+ */
+static int ma35d1serial_remove(struct platform_device *dev)
+{
+       struct uart_port *port = platform_get_drvdata(dev);
+       struct uart_ma35d1_port *up = to_ma35d1_uart_port(port);
+
+       uart_remove_one_port(&ma35d1serial_reg, port);
+       clk_disable_unprepare(up->clk);
+       return 0;
+}
+
+static int ma35d1serial_suspend(struct platform_device *dev, pm_message_t state)
+{
+       struct uart_port *port = platform_get_drvdata(dev);
+       struct uart_ma35d1_port *up = to_ma35d1_uart_port(port);
+
+       uart_suspend_port(&ma35d1serial_reg, &up->port);
+       if (up->port.line == 0) {
+               up->console_baud_rate = serial_in(up, MA35_BAUD_REG);
+               up->console_line = serial_in(up, MA35_LCR_REG);
+               up->console_int = serial_in(up, MA35_IER_REG);
+       }
+       return 0;
+}
+
+static int ma35d1serial_resume(struct platform_device *dev)
+{
+       struct uart_port *port = platform_get_drvdata(dev);
+       struct uart_ma35d1_port *up = to_ma35d1_uart_port(port);
+
+       if (up->port.line == 0) {
+               serial_out(up, MA35_BAUD_REG, up->console_baud_rate);
+               serial_out(up, MA35_LCR_REG, up->console_line);
+               serial_out(up, MA35_IER_REG, up->console_int);
+       }
+       uart_resume_port(&ma35d1serial_reg, &up->port);
+       return 0;
+}
+
+static struct platform_driver ma35d1serial_driver = {
+       .probe      = ma35d1serial_probe,
+       .remove     = ma35d1serial_remove,
+       .suspend    = ma35d1serial_suspend,
+       .resume     = ma35d1serial_resume,
+       .driver     = {
+               .name   = "ma35d1-uart",
+               .owner  = THIS_MODULE,
+               .of_match_table = of_match_ptr(ma35d1_serial_of_match),
+       },
+};
+
+static int __init ma35d1serial_init(void)
+{
+       int ret;
+
+       ret = uart_register_driver(&ma35d1serial_reg);
+       if (ret)
+               return ret;
+
+       ret = platform_driver_register(&ma35d1serial_driver);
+       if (ret)
+               uart_unregister_driver(&ma35d1serial_reg);
+
+       return ret;
+}
+
+static void __exit ma35d1serial_exit(void)
+{
+       platform_driver_unregister(&ma35d1serial_driver);
+       uart_unregister_driver(&ma35d1serial_reg);
+}
+
+module_init(ma35d1serial_init);
+module_exit(ma35d1serial_exit);
+
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("MA35D1 serial driver");
index 9fee722..997e394 100644 (file)
@@ -1636,7 +1636,7 @@ static struct i2c_driver max310x_i2c_driver = {
                .of_match_table = max310x_dt_ids,
                .pm             = &max310x_pm_ops,
        },
-       .probe_new      = max310x_i2c_probe,
+       .probe          = max310x_i2c_probe,
        .remove         = max310x_i2c_remove,
 };
 #endif
index 2a7520a..b29e9df 100644 (file)
@@ -24,6 +24,7 @@
 #include <linux/dmaengine.h>
 #include <linux/dma-mapping.h>
 #include <linux/slab.h>
+#include <linux/math.h>
 #include <linux/module.h>
 #include <linux/ioport.h>
 #include <linux/io.h>
@@ -1459,8 +1460,12 @@ static unsigned int s3c24xx_serial_getclk(struct s3c24xx_uart_port *ourport,
                        continue;
 
                rate = clk_get_rate(clk);
-               if (!rate)
+               if (!rate) {
+                       dev_err(ourport->port.dev,
+                               "Failed to get clock rate for %s.\n", clkname);
+                       clk_put(clk);
                        continue;
+               }
 
                if (ourport->info->has_divslot) {
                        unsigned long div = rate / req_baud;
@@ -1481,15 +1486,21 @@ static unsigned int s3c24xx_serial_getclk(struct s3c24xx_uart_port *ourport,
                }
                quot--;
 
-               calc_deviation = req_baud - baud;
-               if (calc_deviation < 0)
-                       calc_deviation = -calc_deviation;
+               calc_deviation = abs(req_baud - baud);
 
                if (calc_deviation < deviation) {
+                       /*
+                        * If we find a better clk, release the previous one, if
+                        * any.
+                        */
+                       if (!IS_ERR(*best_clk))
+                               clk_put(*best_clk);
                        *best_clk = clk;
                        best_quot = quot;
                        *clk_num = cnt;
                        deviation = calc_deviation;
+               } else {
+                       clk_put(clk);
                }
        }
 
index abad091..2e7e7c4 100644 (file)
@@ -1709,7 +1709,7 @@ static struct i2c_driver sc16is7xx_i2c_uart_driver = {
                .name           = SC16IS7XX_NAME,
                .of_match_table = sc16is7xx_dt_ids,
        },
-       .probe_new      = sc16is7xx_i2c_probe,
+       .probe          = sc16is7xx_i2c_probe,
        .remove         = sc16is7xx_i2c_remove,
        .id_table       = sc16is7xx_i2c_id_table,
 };
diff --git a/drivers/tty/serial/serial_base.h b/drivers/tty/serial/serial_base.h
new file mode 100644 (file)
index 0000000..9faac0f
--- /dev/null
@@ -0,0 +1,46 @@
+/* SPDX-License-Identifier: GPL-2.0+ */
+/*
+ * Serial core related functions, serial port device drivers do not need this.
+ *
+ * Copyright (C) 2023 Texas Instruments Incorporated - https://www.ti.com/
+ * Author: Tony Lindgren <tony@atomide.com>
+ */
+
+#define to_serial_base_ctrl_device(d) container_of((d), struct serial_ctrl_device, dev)
+#define to_serial_base_port_device(d) container_of((d), struct serial_port_device, dev)
+
+struct uart_driver;
+struct uart_port;
+struct device_driver;
+struct device;
+
+struct serial_ctrl_device {
+       struct device dev;
+};
+
+struct serial_port_device {
+       struct device dev;
+       struct uart_port *port;
+};
+
+int serial_base_ctrl_init(void);
+void serial_base_ctrl_exit(void);
+
+int serial_base_port_init(void);
+void serial_base_port_exit(void);
+
+int serial_base_driver_register(struct device_driver *driver);
+void serial_base_driver_unregister(struct device_driver *driver);
+
+struct serial_ctrl_device *serial_base_ctrl_add(struct uart_port *port,
+                                               struct device *parent);
+struct serial_port_device *serial_base_port_add(struct uart_port *port,
+                                               struct serial_ctrl_device *parent);
+void serial_base_ctrl_device_remove(struct serial_ctrl_device *ctrl_dev);
+void serial_base_port_device_remove(struct serial_port_device *port_dev);
+
+int serial_ctrl_register_port(struct uart_driver *drv, struct uart_port *port);
+void serial_ctrl_unregister_port(struct uart_driver *drv, struct uart_port *port);
+
+int serial_core_register_port(struct uart_driver *drv, struct uart_port *port);
+void serial_core_unregister_port(struct uart_driver *drv, struct uart_port *port);
diff --git a/drivers/tty/serial/serial_base_bus.c b/drivers/tty/serial/serial_base_bus.c
new file mode 100644 (file)
index 0000000..6ff59c8
--- /dev/null
@@ -0,0 +1,205 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Serial base bus layer for controllers
+ *
+ * Copyright (C) 2023 Texas Instruments Incorporated - https://www.ti.com/
+ * Author: Tony Lindgren <tony@atomide.com>
+ *
+ * The serial core bus manages the serial core controller instances.
+ */
+
+#include <linux/container_of.h>
+#include <linux/device.h>
+#include <linux/module.h>
+#include <linux/serial_core.h>
+#include <linux/slab.h>
+#include <linux/spinlock.h>
+
+#include "serial_base.h"
+
+static bool serial_base_initialized;
+
+static int serial_base_match(struct device *dev, struct device_driver *drv)
+{
+       int len = strlen(drv->name);
+
+       return !strncmp(dev_name(dev), drv->name, len);
+}
+
+static struct bus_type serial_base_bus_type = {
+       .name = "serial-base",
+       .match = serial_base_match,
+};
+
+int serial_base_driver_register(struct device_driver *driver)
+{
+       driver->bus = &serial_base_bus_type;
+
+       return driver_register(driver);
+}
+
+void serial_base_driver_unregister(struct device_driver *driver)
+{
+       driver_unregister(driver);
+}
+
+static int serial_base_device_init(struct uart_port *port,
+                                  struct device *dev,
+                                  struct device *parent_dev,
+                                  const struct device_type *type,
+                                  void (*release)(struct device *dev),
+                                  int id)
+{
+       device_initialize(dev);
+       dev->type = type;
+       dev->parent = parent_dev;
+       dev->bus = &serial_base_bus_type;
+       dev->release = release;
+
+       if (!serial_base_initialized) {
+               dev_dbg(port->dev, "uart_add_one_port() called before arch_initcall()?\n");
+               return -EPROBE_DEFER;
+       }
+
+       return dev_set_name(dev, "%s.%s.%d", type->name, dev_name(port->dev), id);
+}
+
+static const struct device_type serial_ctrl_type = {
+       .name = "ctrl",
+};
+
+static void serial_base_ctrl_release(struct device *dev)
+{
+       struct serial_ctrl_device *ctrl_dev = to_serial_base_ctrl_device(dev);
+
+       kfree(ctrl_dev);
+}
+
+void serial_base_ctrl_device_remove(struct serial_ctrl_device *ctrl_dev)
+{
+       if (!ctrl_dev)
+               return;
+
+       device_del(&ctrl_dev->dev);
+}
+
+struct serial_ctrl_device *serial_base_ctrl_add(struct uart_port *port,
+                                               struct device *parent)
+{
+       struct serial_ctrl_device *ctrl_dev;
+       int err;
+
+       ctrl_dev = kzalloc(sizeof(*ctrl_dev), GFP_KERNEL);
+       if (!ctrl_dev)
+               return ERR_PTR(-ENOMEM);
+
+       err = serial_base_device_init(port, &ctrl_dev->dev,
+                                     parent, &serial_ctrl_type,
+                                     serial_base_ctrl_release,
+                                     port->ctrl_id);
+       if (err)
+               goto err_put_device;
+
+       err = device_add(&ctrl_dev->dev);
+       if (err)
+               goto err_put_device;
+
+       return ctrl_dev;
+
+err_put_device:
+       put_device(&ctrl_dev->dev);
+
+       return ERR_PTR(err);
+}
+
+static const struct device_type serial_port_type = {
+       .name = "port",
+};
+
+static void serial_base_port_release(struct device *dev)
+{
+       struct serial_port_device *port_dev = to_serial_base_port_device(dev);
+
+       kfree(port_dev);
+}
+
+struct serial_port_device *serial_base_port_add(struct uart_port *port,
+                                               struct serial_ctrl_device *ctrl_dev)
+{
+       struct serial_port_device *port_dev;
+       int err;
+
+       port_dev = kzalloc(sizeof(*port_dev), GFP_KERNEL);
+       if (!port_dev)
+               return ERR_PTR(-ENOMEM);
+
+       err = serial_base_device_init(port, &port_dev->dev,
+                                     &ctrl_dev->dev, &serial_port_type,
+                                     serial_base_port_release,
+                                     port->line);
+       if (err)
+               goto err_put_device;
+
+       port_dev->port = port;
+
+       err = device_add(&port_dev->dev);
+       if (err)
+               goto err_put_device;
+
+       return port_dev;
+
+err_put_device:
+       put_device(&port_dev->dev);
+
+       return ERR_PTR(err);
+}
+
+void serial_base_port_device_remove(struct serial_port_device *port_dev)
+{
+       if (!port_dev)
+               return;
+
+       device_del(&port_dev->dev);
+}
+
+static int serial_base_init(void)
+{
+       int ret;
+
+       ret = bus_register(&serial_base_bus_type);
+       if (ret)
+               return ret;
+
+       ret = serial_base_ctrl_init();
+       if (ret)
+               goto err_bus_unregister;
+
+       ret = serial_base_port_init();
+       if (ret)
+               goto err_ctrl_exit;
+
+       serial_base_initialized = true;
+
+       return 0;
+
+err_ctrl_exit:
+       serial_base_ctrl_exit();
+
+err_bus_unregister:
+       bus_unregister(&serial_base_bus_type);
+
+       return ret;
+}
+arch_initcall(serial_base_init);
+
+static void serial_base_exit(void)
+{
+       serial_base_port_exit();
+       serial_base_ctrl_exit();
+       bus_unregister(&serial_base_bus_type);
+}
+module_exit(serial_base_exit);
+
+MODULE_AUTHOR("Tony Lindgren <tony@atomide.com>");
+MODULE_DESCRIPTION("Serial core bus");
+MODULE_LICENSE("GPL");
index 54e82f4..831d033 100644 (file)
@@ -17,6 +17,7 @@
 #include <linux/gpio/consumer.h>
 #include <linux/kernel.h>
 #include <linux/of.h>
+#include <linux/pm_runtime.h>
 #include <linux/proc_fs.h>
 #include <linux/seq_file.h>
 #include <linux/device.h>
@@ -31,6 +32,8 @@
 #include <linux/irq.h>
 #include <linux/uaccess.h>
 
+#include "serial_base.h"
+
 /*
  * This is used to lock changes in serial line configuration.
  */
@@ -134,9 +137,30 @@ static void __uart_start(struct tty_struct *tty)
 {
        struct uart_state *state = tty->driver_data;
        struct uart_port *port = state->uart_port;
+       struct serial_port_device *port_dev;
+       int err;
+
+       if (!port || port->flags & UPF_DEAD || uart_tx_stopped(port))
+               return;
+
+       port_dev = port->port_dev;
+
+       /* Increment the runtime PM usage count for the active check below */
+       err = pm_runtime_get(&port_dev->dev);
+       if (err < 0) {
+               pm_runtime_put_noidle(&port_dev->dev);
+               return;
+       }
 
-       if (port && !(port->flags & UPF_DEAD) && !uart_tx_stopped(port))
+       /*
+        * Start TX if enabled, and kick runtime PM. If the device is not
+        * enabled, serial_port_runtime_resume() calls start_tx() again
+        * after enabling the device.
+        */
+       if (pm_runtime_active(&port_dev->dev))
                port->ops->start_tx(port);
+       pm_runtime_mark_last_busy(&port_dev->dev);
+       pm_runtime_put_autosuspend(&port_dev->dev);
 }
 
 static void uart_start(struct tty_struct *tty)
@@ -2333,8 +2357,11 @@ int uart_suspend_port(struct uart_driver *drv, struct uart_port *uport)
         * able to Re-start_rx later.
         */
        if (!console_suspend_enabled && uart_console(uport)) {
-               if (uport->ops->start_rx)
+               if (uport->ops->start_rx) {
+                       spin_lock_irq(&uport->lock);
                        uport->ops->stop_rx(uport);
+                       spin_unlock_irq(&uport->lock);
+               }
                goto unlock;
        }
 
@@ -2427,8 +2454,11 @@ int uart_resume_port(struct uart_driver *drv, struct uart_port *uport)
                if (console_suspend_enabled)
                        uart_change_pm(state, UART_PM_STATE_ON);
                uport->ops->set_termios(uport, &termios, NULL);
-               if (!console_suspend_enabled && uport->ops->start_rx)
+               if (!console_suspend_enabled && uport->ops->start_rx) {
+                       spin_lock_irq(&uport->lock);
                        uport->ops->start_rx(uport);
+                       spin_unlock_irq(&uport->lock);
+               }
                if (console_suspend_enabled)
                        console_start(uport->cons);
        }
@@ -3042,7 +3072,7 @@ static const struct attribute_group tty_dev_attr_group = {
 };
 
 /**
- * uart_add_one_port - attach a driver-defined port structure
+ * serial_core_add_one_port - attach a driver-defined port structure
  * @drv: pointer to the uart low level driver structure for this port
  * @uport: uart port structure to use for this port.
  *
@@ -3051,8 +3081,9 @@ static const struct attribute_group tty_dev_attr_group = {
  * This allows the driver @drv to register its own uart_port structure with the
  * core driver. The main purpose is to allow the low level uart drivers to
  * expand uart_port, rather than having yet more levels of structures.
+ * Caller must hold port_mutex.
  */
-int uart_add_one_port(struct uart_driver *drv, struct uart_port *uport)
+static int serial_core_add_one_port(struct uart_driver *drv, struct uart_port *uport)
 {
        struct uart_state *state;
        struct tty_port *port;
@@ -3066,7 +3097,6 @@ int uart_add_one_port(struct uart_driver *drv, struct uart_port *uport)
        state = drv->state + uport->line;
        port = &state->port;
 
-       mutex_lock(&port_mutex);
        mutex_lock(&port->mutex);
        if (state->uart_port) {
                ret = -EINVAL;
@@ -3131,21 +3161,14 @@ int uart_add_one_port(struct uart_driver *drv, struct uart_port *uport)
                       uport->line);
        }
 
-       /*
-        * Ensure UPF_DEAD is not set.
-        */
-       uport->flags &= ~UPF_DEAD;
-
  out:
        mutex_unlock(&port->mutex);
-       mutex_unlock(&port_mutex);
 
        return ret;
 }
-EXPORT_SYMBOL(uart_add_one_port);
 
 /**
- * uart_remove_one_port - detach a driver defined port structure
+ * serial_core_remove_one_port - detach a driver defined port structure
  * @drv: pointer to the uart low level driver structure for this port
  * @uport: uart port structure for this port
  *
@@ -3153,21 +3176,16 @@ EXPORT_SYMBOL(uart_add_one_port);
  *
  * This unhooks (and hangs up) the specified port structure from the core
  * driver. No further calls will be made to the low-level code for this port.
+ * Caller must hold port_mutex.
  */
-int uart_remove_one_port(struct uart_driver *drv, struct uart_port *uport)
+static void serial_core_remove_one_port(struct uart_driver *drv,
+                                       struct uart_port *uport)
 {
        struct uart_state *state = drv->state + uport->line;
        struct tty_port *port = &state->port;
        struct uart_port *uart_port;
        struct tty_struct *tty;
-       int ret = 0;
-
-       mutex_lock(&port_mutex);
 
-       /*
-        * Mark the port "dead" - this prevents any opens from
-        * succeeding while we shut down the port.
-        */
        mutex_lock(&port->mutex);
        uart_port = uart_port_check(state);
        if (uart_port != uport)
@@ -3176,10 +3194,8 @@ int uart_remove_one_port(struct uart_driver *drv, struct uart_port *uport)
 
        if (!uart_port) {
                mutex_unlock(&port->mutex);
-               ret = -EINVAL;
-               goto out;
+               return;
        }
-       uport->flags |= UPF_DEAD;
        mutex_unlock(&port->mutex);
 
        /*
@@ -3211,18 +3227,14 @@ int uart_remove_one_port(struct uart_driver *drv, struct uart_port *uport)
         * Indicate that there isn't a port here anymore.
         */
        uport->type = PORT_UNKNOWN;
+       uport->port_dev = NULL;
 
        mutex_lock(&port->mutex);
        WARN_ON(atomic_dec_return(&state->refcount) < 0);
        wait_event(state->remove_wait, !atomic_read(&state->refcount));
        state->uart_port = NULL;
        mutex_unlock(&port->mutex);
-out:
-       mutex_unlock(&port_mutex);
-
-       return ret;
 }
-EXPORT_SYMBOL(uart_remove_one_port);
 
 /**
  * uart_match_port - are the two ports equivalent?
@@ -3257,6 +3269,144 @@ bool uart_match_port(const struct uart_port *port1,
 }
 EXPORT_SYMBOL(uart_match_port);
 
+static struct serial_ctrl_device *
+serial_core_get_ctrl_dev(struct serial_port_device *port_dev)
+{
+       struct device *dev = &port_dev->dev;
+
+       return to_serial_base_ctrl_device(dev->parent);
+}
+
+/*
+ * Find a registered serial core controller device if one exists. Returns
+ * the first device matching the ctrl_id. Caller must hold port_mutex.
+ */
+static struct serial_ctrl_device *serial_core_ctrl_find(struct uart_driver *drv,
+                                                       struct device *phys_dev,
+                                                       int ctrl_id)
+{
+       struct uart_state *state;
+       int i;
+
+       lockdep_assert_held(&port_mutex);
+
+       for (i = 0; i < drv->nr; i++) {
+               state = drv->state + i;
+               if (!state->uart_port || !state->uart_port->port_dev)
+                       continue;
+
+               if (state->uart_port->dev == phys_dev &&
+                   state->uart_port->ctrl_id == ctrl_id)
+                       return serial_core_get_ctrl_dev(state->uart_port->port_dev);
+       }
+
+       return NULL;
+}
+
+static struct serial_ctrl_device *serial_core_ctrl_device_add(struct uart_port *port)
+{
+       return serial_base_ctrl_add(port, port->dev);
+}
+
+static int serial_core_port_device_add(struct serial_ctrl_device *ctrl_dev,
+                                      struct uart_port *port)
+{
+       struct serial_port_device *port_dev;
+
+       port_dev = serial_base_port_add(port, ctrl_dev);
+       if (IS_ERR(port_dev))
+               return PTR_ERR(port_dev);
+
+       port->port_dev = port_dev;
+
+       return 0;
+}
+
+/*
+ * Initialize a serial core port device, and a controller device if needed.
+ */
+int serial_core_register_port(struct uart_driver *drv, struct uart_port *port)
+{
+       struct serial_ctrl_device *ctrl_dev, *new_ctrl_dev = NULL;
+       int ret;
+
+       mutex_lock(&port_mutex);
+
+       /*
+        * Prevent serial_port_runtime_resume() from trying to use the port
+        * until serial_core_add_one_port() has completed
+        */
+       port->flags |= UPF_DEAD;
+
+       /* Inititalize a serial core controller device if needed */
+       ctrl_dev = serial_core_ctrl_find(drv, port->dev, port->ctrl_id);
+       if (!ctrl_dev) {
+               new_ctrl_dev = serial_core_ctrl_device_add(port);
+               if (IS_ERR(new_ctrl_dev)) {
+                       ret = PTR_ERR(new_ctrl_dev);
+                       goto err_unlock;
+               }
+               ctrl_dev = new_ctrl_dev;
+       }
+
+       /*
+        * Initialize a serial core port device. Tag the port dead to prevent
+        * serial_port_runtime_resume() trying to do anything until port has
+        * been registered. It gets cleared by serial_core_add_one_port().
+        */
+       ret = serial_core_port_device_add(ctrl_dev, port);
+       if (ret)
+               goto err_unregister_ctrl_dev;
+
+       ret = serial_core_add_one_port(drv, port);
+       if (ret)
+               goto err_unregister_port_dev;
+
+       port->flags &= ~UPF_DEAD;
+
+       mutex_unlock(&port_mutex);
+
+       return 0;
+
+err_unregister_port_dev:
+       serial_base_port_device_remove(port->port_dev);
+
+err_unregister_ctrl_dev:
+       serial_base_ctrl_device_remove(new_ctrl_dev);
+
+err_unlock:
+       mutex_unlock(&port_mutex);
+
+       return ret;
+}
+
+/*
+ * Removes a serial core port device, and the related serial core controller
+ * device if the last instance.
+ */
+void serial_core_unregister_port(struct uart_driver *drv, struct uart_port *port)
+{
+       struct device *phys_dev = port->dev;
+       struct serial_port_device *port_dev = port->port_dev;
+       struct serial_ctrl_device *ctrl_dev = serial_core_get_ctrl_dev(port_dev);
+       int ctrl_id = port->ctrl_id;
+
+       mutex_lock(&port_mutex);
+
+       port->flags |= UPF_DEAD;
+
+       serial_core_remove_one_port(drv, port);
+
+       /* Note that struct uart_port *port is no longer valid at this point */
+       serial_base_port_device_remove(port_dev);
+
+       /* Drop the serial core controller device if no ports are using it */
+       if (!serial_core_ctrl_find(drv, phys_dev, ctrl_id))
+               serial_base_ctrl_device_remove(ctrl_dev);
+
+       mutex_unlock(&port_mutex);
+}
+
 /**
  * uart_handle_dcd_change - handle a change of carrier detect state
  * @uport: uart_port structure for the open port
diff --git a/drivers/tty/serial/serial_ctrl.c b/drivers/tty/serial/serial_ctrl.c
new file mode 100644 (file)
index 0000000..6fcf634
--- /dev/null
@@ -0,0 +1,68 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Serial core controller driver
+ *
+ * Copyright (C) 2023 Texas Instruments Incorporated - https://www.ti.com/
+ * Author: Tony Lindgren <tony@atomide.com>
+ *
+ * This driver manages the serial core controller struct device instances.
+ * The serial core controller devices are children of the physical serial
+ * port device.
+ */
+
+#include <linux/device.h>
+#include <linux/module.h>
+#include <linux/pm_runtime.h>
+#include <linux/serial_core.h>
+#include <linux/spinlock.h>
+
+#include "serial_base.h"
+
+static int serial_ctrl_probe(struct device *dev)
+{
+       pm_runtime_enable(dev);
+
+       return 0;
+}
+
+static int serial_ctrl_remove(struct device *dev)
+{
+       pm_runtime_disable(dev);
+
+       return 0;
+}
+
+/*
+ * Serial core controller device init functions. Note that the physical
+ * serial port device driver may not have completed probe at this point.
+ */
+int serial_ctrl_register_port(struct uart_driver *drv, struct uart_port *port)
+{
+       return serial_core_register_port(drv, port);
+}
+
+void serial_ctrl_unregister_port(struct uart_driver *drv, struct uart_port *port)
+{
+       serial_core_unregister_port(drv, port);
+}
+
+static struct device_driver serial_ctrl_driver = {
+       .name = "ctrl",
+       .suppress_bind_attrs = true,
+       .probe = serial_ctrl_probe,
+       .remove = serial_ctrl_remove,
+};
+
+int serial_base_ctrl_init(void)
+{
+       return serial_base_driver_register(&serial_ctrl_driver);
+}
+
+void serial_base_ctrl_exit(void)
+{
+       serial_base_driver_unregister(&serial_ctrl_driver);
+}
+
+MODULE_AUTHOR("Tony Lindgren <tony@atomide.com>");
+MODULE_DESCRIPTION("Serial core controller driver");
+MODULE_LICENSE("GPL");
diff --git a/drivers/tty/serial/serial_port.c b/drivers/tty/serial/serial_port.c
new file mode 100644 (file)
index 0000000..8624232
--- /dev/null
@@ -0,0 +1,105 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Serial core port device driver
+ *
+ * Copyright (C) 2023 Texas Instruments Incorporated - https://www.ti.com/
+ * Author: Tony Lindgren <tony@atomide.com>
+ */
+
+#include <linux/device.h>
+#include <linux/module.h>
+#include <linux/pm_runtime.h>
+#include <linux/serial_core.h>
+#include <linux/spinlock.h>
+
+#include "serial_base.h"
+
+#define SERIAL_PORT_AUTOSUSPEND_DELAY_MS       500
+
+/* Only considers pending TX for now. Caller must take care of locking */
+static int __serial_port_busy(struct uart_port *port)
+{
+       return !uart_tx_stopped(port) &&
+               uart_circ_chars_pending(&port->state->xmit);
+}
+
+static int serial_port_runtime_resume(struct device *dev)
+{
+       struct serial_port_device *port_dev = to_serial_base_port_device(dev);
+       struct uart_port *port;
+       unsigned long flags;
+
+       port = port_dev->port;
+
+       if (port->flags & UPF_DEAD)
+               goto out;
+
+       /* Flush any pending TX for the port */
+       spin_lock_irqsave(&port->lock, flags);
+       if (__serial_port_busy(port))
+               port->ops->start_tx(port);
+       spin_unlock_irqrestore(&port->lock, flags);
+
+out:
+       pm_runtime_mark_last_busy(dev);
+
+       return 0;
+}
+
+static DEFINE_RUNTIME_DEV_PM_OPS(serial_port_pm,
+                                NULL, serial_port_runtime_resume, NULL);
+
+static int serial_port_probe(struct device *dev)
+{
+       pm_runtime_enable(dev);
+       pm_runtime_set_autosuspend_delay(dev, SERIAL_PORT_AUTOSUSPEND_DELAY_MS);
+       pm_runtime_use_autosuspend(dev);
+
+       return 0;
+}
+
+static int serial_port_remove(struct device *dev)
+{
+       pm_runtime_dont_use_autosuspend(dev);
+       pm_runtime_disable(dev);
+
+       return 0;
+}
+
+/*
+ * Serial core port device init functions. Note that the physical serial
+ * port device driver may not have completed probe at this point.
+ */
+int uart_add_one_port(struct uart_driver *drv, struct uart_port *port)
+{
+       return serial_ctrl_register_port(drv, port);
+}
+EXPORT_SYMBOL(uart_add_one_port);
+
+void uart_remove_one_port(struct uart_driver *drv, struct uart_port *port)
+{
+       serial_ctrl_unregister_port(drv, port);
+}
+EXPORT_SYMBOL(uart_remove_one_port);
+
+static struct device_driver serial_port_driver = {
+       .name = "port",
+       .suppress_bind_attrs = true,
+       .probe = serial_port_probe,
+       .remove = serial_port_remove,
+       .pm = pm_ptr(&serial_port_pm),
+};
+
+int serial_base_port_init(void)
+{
+       return serial_base_driver_register(&serial_port_driver);
+}
+
+void serial_base_port_exit(void)
+{
+       serial_base_driver_unregister(&serial_port_driver);
+}
+
+MODULE_AUTHOR("Tony Lindgren <tony@atomide.com>");
+MODULE_DESCRIPTION("Serial controller port driver");
+MODULE_LICENSE("GPL");
index 5215e69..aa471c9 100644 (file)
@@ -754,7 +754,7 @@ static struct asc_port *asc_of_get_asc_port(struct platform_device *pdev)
 
        asc_ports[id].hw_flow_control = of_property_read_bool(np,
                                                        "uart-has-rtscts");
-       asc_ports[id].force_m1 =  of_property_read_bool(np, "st,force_m1");
+       asc_ports[id].force_m1 =  of_property_read_bool(np, "st,force-m1");
        asc_ports[id].port.line = id;
        asc_ports[id].rts = NULL;
 
@@ -796,7 +796,9 @@ static int asc_serial_remove(struct platform_device *pdev)
 {
        struct uart_port *port = platform_get_drvdata(pdev);
 
-       return uart_remove_one_port(&asc_uart_driver, port);
+       uart_remove_one_port(&asc_uart_driver, port);
+
+       return 0;
 }
 
 #ifdef CONFIG_PM_SLEEP
index 1e38fc9..e9e11a2 100644 (file)
@@ -1755,13 +1755,10 @@ static int stm32_usart_serial_remove(struct platform_device *pdev)
        struct uart_port *port = platform_get_drvdata(pdev);
        struct stm32_port *stm32_port = to_stm32_port(port);
        const struct stm32_usart_offsets *ofs = &stm32_port->info->ofs;
-       int err;
        u32 cr3;
 
        pm_runtime_get_sync(&pdev->dev);
-       err = uart_remove_one_port(&stm32_usart_driver, port);
-       if (err)
-               return(err);
+       uart_remove_one_port(&stm32_usart_driver, port);
 
        pm_runtime_disable(&pdev->dev);
        pm_runtime_set_suspended(&pdev->dev);
index 94584e5..6795748 100644 (file)
@@ -685,18 +685,15 @@ static int ulite_assign(struct device *dev, int id, phys_addr_t base, int irq,
  *
  * @dev: pointer to device structure
  */
-static int ulite_release(struct device *dev)
+static void ulite_release(struct device *dev)
 {
        struct uart_port *port = dev_get_drvdata(dev);
-       int rc = 0;
 
        if (port) {
-               rc = uart_remove_one_port(&ulite_uart_driver, port);
+               uart_remove_one_port(&ulite_uart_driver, port);
                dev_set_drvdata(dev, NULL);
                port->mapbase = 0;
        }
-
-       return rc;
 }
 
 /**
@@ -900,14 +897,13 @@ static int ulite_remove(struct platform_device *pdev)
 {
        struct uart_port *port = dev_get_drvdata(&pdev->dev);
        struct uartlite_data *pdata = port->private_data;
-       int rc;
 
        clk_disable_unprepare(pdata->clk);
-       rc = ulite_release(&pdev->dev);
+       ulite_release(&pdev->dev);
        pm_runtime_disable(&pdev->dev);
        pm_runtime_set_suspended(&pdev->dev);
        pm_runtime_dont_use_autosuspend(&pdev->dev);
-       return rc;
+       return 0;
 }
 
 /* work with hotplug and coldplug */
index 8e521c6..20a7516 100644 (file)
@@ -1670,14 +1670,13 @@ static int cdns_uart_remove(struct platform_device *pdev)
 {
        struct uart_port *port = platform_get_drvdata(pdev);
        struct cdns_uart *cdns_uart_data = port->private_data;
-       int rc;
 
        /* Remove the cdns_uart port from the serial core */
 #ifdef CONFIG_COMMON_CLK
        clk_notifier_unregister(cdns_uart_data->uartclk,
                        &cdns_uart_data->clk_rate_change_nb);
 #endif
-       rc = uart_remove_one_port(cdns_uart_data->cdns_uart_driver, port);
+       uart_remove_one_port(cdns_uart_data->cdns_uart_driver, port);
        port->mapbase = 0;
        clk_disable_unprepare(cdns_uart_data->uartclk);
        clk_disable_unprepare(cdns_uart_data->pclk);
@@ -1693,7 +1692,7 @@ static int cdns_uart_remove(struct platform_device *pdev)
 
        if (!--instances)
                uart_unregister_driver(cdns_uart_data->cdns_uart_driver);
-       return rc;
+       return 0;
 }
 
 static struct platform_driver cdns_uart_platform_driver = {
index 1e0d80e..89769a1 100644 (file)
@@ -99,14 +99,15 @@ extern int tty_ldisc_autoload;
 
 /* tty_audit.c */
 #ifdef CONFIG_AUDIT
-void tty_audit_add_data(struct tty_struct *tty, const void *data, size_t size);
-void tty_audit_tiocsti(struct tty_struct *tty, char ch);
+void tty_audit_add_data(const struct tty_struct *tty, const void *data,
+                       size_t size);
+void tty_audit_tiocsti(const struct tty_struct *tty, char ch);
 #else
-static inline void tty_audit_add_data(struct tty_struct *tty, const void *data,
-                                     size_t size)
+static inline void tty_audit_add_data(const struct tty_struct *tty,
+                                     const void *data, size_t size)
 {
 }
-static inline void tty_audit_tiocsti(struct tty_struct *tty, char ch)
+static inline void tty_audit_tiocsti(const struct tty_struct *tty, char ch)
 {
 }
 #endif
index ca7afd7..24d0105 100644 (file)
@@ -15,7 +15,7 @@
 struct tty_audit_buf {
        struct mutex mutex;     /* Protects all data below */
        dev_t dev;              /* The TTY which the data is from */
-       unsigned icanon:1;
+       bool icanon;
        size_t valid;
        unsigned char *data;    /* Allocated size N_TTY_BUF_SIZE */
 };
@@ -33,16 +33,16 @@ static struct tty_audit_buf *tty_audit_buf_alloc(void)
 {
        struct tty_audit_buf *buf;
 
-       buf = kmalloc(sizeof(*buf), GFP_KERNEL);
+       buf = kzalloc(sizeof(*buf), GFP_KERNEL);
        if (!buf)
                goto err;
+
        buf->data = kmalloc(N_TTY_BUF_SIZE, GFP_KERNEL);
        if (!buf->data)
                goto err_buf;
+
        mutex_init(&buf->mutex);
-       buf->dev = MKDEV(0, 0);
-       buf->icanon = 0;
-       buf->valid = 0;
+
        return buf;
 
 err_buf:
@@ -59,27 +59,27 @@ static void tty_audit_buf_free(struct tty_audit_buf *buf)
 }
 
 static void tty_audit_log(const char *description, dev_t dev,
-                         unsigned char *data, size_t size)
+                         const unsigned char *data, size_t size)
 {
        struct audit_buffer *ab;
        pid_t pid = task_pid_nr(current);
        uid_t uid = from_kuid(&init_user_ns, task_uid(current));
        uid_t loginuid = from_kuid(&init_user_ns, audit_get_loginuid(current));
        unsigned int sessionid = audit_get_sessionid(current);
+       char name[TASK_COMM_LEN];
 
        ab = audit_log_start(audit_context(), GFP_KERNEL, AUDIT_TTY);
-       if (ab) {
-               char name[sizeof(current->comm)];
-
-               audit_log_format(ab, "%s pid=%u uid=%u auid=%u ses=%u major=%d"
-                                " minor=%d comm=", description, pid, uid,
-                                loginuid, sessionid, MAJOR(dev), MINOR(dev));
-               get_task_comm(name, current);
-               audit_log_untrustedstring(ab, name);
-               audit_log_format(ab, " data=");
-               audit_log_n_hex(ab, data, size);
-               audit_log_end(ab);
-       }
+       if (!ab)
+               return;
+
+       audit_log_format(ab, "%s pid=%u uid=%u auid=%u ses=%u major=%d minor=%d comm=",
+                        description, pid, uid, loginuid, sessionid,
+                        MAJOR(dev), MINOR(dev));
+       get_task_comm(name, current);
+       audit_log_untrustedstring(ab, name);
+       audit_log_format(ab, " data=");
+       audit_log_n_hex(ab, data, size);
+       audit_log_end(ab);
 }
 
 /*
@@ -134,7 +134,7 @@ void tty_audit_fork(struct signal_struct *sig)
 /*
  *     tty_audit_tiocsti       -       Log TIOCSTI
  */
-void tty_audit_tiocsti(struct tty_struct *tty, char ch)
+void tty_audit_tiocsti(const struct tty_struct *tty, char ch)
 {
        dev_t dev;
 
@@ -199,11 +199,12 @@ static struct tty_audit_buf *tty_audit_buf_get(void)
  *
  *     Audit @data of @size from @tty, if necessary.
  */
-void tty_audit_add_data(struct tty_struct *tty, const void *data, size_t size)
+void tty_audit_add_data(const struct tty_struct *tty, const void *data,
+                       size_t size)
 {
        struct tty_audit_buf *buf;
-       unsigned int icanon = !!L_ICANON(tty);
        unsigned int audit_tty;
+       bool icanon = L_ICANON(tty);
        dev_t dev;
 
        audit_tty = READ_ONCE(current->signal->audit_tty);
index 4737a8f..3959efc 100644 (file)
 #include <linux/compat.h>
 #include <linux/uaccess.h>
 #include <linux/termios_internal.h>
+#include <linux/fs.h>
 
 #include <linux/kbd_kern.h>
 #include <linux/vt_kern.h>
@@ -811,18 +812,26 @@ void start_tty(struct tty_struct *tty)
 }
 EXPORT_SYMBOL(start_tty);
 
-static void tty_update_time(struct timespec64 *time)
+static void tty_update_time(struct tty_struct *tty, bool mtime)
 {
        time64_t sec = ktime_get_real_seconds();
+       struct tty_file_private *priv;
 
-       /*
-        * We only care if the two values differ in anything other than the
-        * lower three bits (i.e every 8 seconds).  If so, then we can update
-        * the time of the tty device, otherwise it could be construded as a
-        * security leak to let userspace know the exact timing of the tty.
-        */
-       if ((sec ^ time->tv_sec) & ~7)
-               time->tv_sec = sec;
+       spin_lock(&tty->files_lock);
+       list_for_each_entry(priv, &tty->tty_files, list) {
+               struct inode *inode = file_inode(priv->file);
+               struct timespec64 *time = mtime ? &inode->i_mtime : &inode->i_atime;
+
+               /*
+                * We only care if the two values differ in anything other than the
+                * lower three bits (i.e every 8 seconds).  If so, then we can update
+                * the time of the tty device, otherwise it could be construded as a
+                * security leak to let userspace know the exact timing of the tty.
+                */
+               if ((sec ^ time->tv_sec) & ~7)
+                       time->tv_sec = sec;
+       }
+       spin_unlock(&tty->files_lock);
 }
 
 /*
@@ -928,7 +937,7 @@ static ssize_t tty_read(struct kiocb *iocb, struct iov_iter *to)
        tty_ldisc_deref(ld);
 
        if (i > 0)
-               tty_update_time(&inode->i_atime);
+               tty_update_time(tty, false);
 
        return i;
 }
@@ -1036,7 +1045,7 @@ static inline ssize_t do_tty_write(
                cond_resched();
        }
        if (written) {
-               tty_update_time(&file_inode(file)->i_mtime);
+               tty_update_time(tty, true);
                ret = written;
        }
 out:
index 6f78f30..be65de6 100644 (file)
@@ -7,17 +7,34 @@
 #ifndef _LINUX_SERIAL_8250_H
 #define _LINUX_SERIAL_8250_H
 
+#include <linux/errno.h>
 #include <linux/serial_core.h>
 #include <linux/serial_reg.h>
 #include <linux/platform_device.h>
 
+struct uart_8250_port;
+
 /*
  * This is the platform device platform_data structure
+ *
+ * @mapsize:   Port size for ioremap()
+ * @bugs:      Port bugs
+ *
+ * @dl_read: ``u32 ()(struct uart_8250_port *up)``
+ *
+ *     UART divisor latch read.
+ *
+ * @dl_write: ``void ()(struct uart_8250_port *up, u32 value)``
+ *
+ *     Write @value into UART divisor latch.
+ *
+ *     Locking: Caller holds port's lock.
  */
 struct plat_serial8250_port {
        unsigned long   iobase;         /* io base address */
        void __iomem    *membase;       /* ioremap cookie or NULL */
        resource_size_t mapbase;        /* resource base */
+       resource_size_t mapsize;
        unsigned int    uartclk;        /* UART clock rate */
        unsigned int    irq;            /* interrupt number */
        unsigned long   irqflags;       /* request_irq flags */
@@ -28,8 +45,11 @@ struct plat_serial8250_port {
        unsigned char   has_sysrq;      /* supports magic SysRq */
        unsigned int    type;           /* If UPF_FIXED_TYPE */
        upf_t           flags;          /* UPF_* flags */
+       u16             bugs;           /* port bugs */
        unsigned int    (*serial_in)(struct uart_port *, int);
        void            (*serial_out)(struct uart_port *, int, int);
+       u32             (*dl_read)(struct uart_8250_port *up);
+       void            (*dl_write)(struct uart_8250_port *up, u32 value);
        void            (*set_termios)(struct uart_port *,
                                       struct ktermios *new,
                                       const struct ktermios *old);
@@ -90,15 +110,23 @@ struct uart_8250_em485 {
  * their own 8250 ports without registering their own
  * platform device.  Using these will make your driver
  * dependent on the 8250 driver.
+ *
+ * @dl_read: ``u32 ()(struct uart_8250_port *port)``
+ *
+ *     UART divisor latch read.
+ *
+ * @dl_write: ``void ()(struct uart_8250_port *port, u32 value)``
+ *
+ *     Write @value into UART divisor latch.
+ *
+ *     Locking: Caller holds port's lock.
  */
-
 struct uart_8250_port {
        struct uart_port        port;
        struct timer_list       timer;          /* "no irq" timer */
        struct list_head        list;           /* ports on this IRQ */
        u32                     capabilities;   /* port capabilities */
-       unsigned short          bugs;           /* port bugs */
-       bool                    fifo_bug;       /* min RX trigger if enabled */
+       u16                     bugs;           /* port bugs */
        unsigned int            tx_loadsz;      /* transmit fifo load size */
        unsigned char           acr;
        unsigned char           fcr;
@@ -129,8 +157,8 @@ struct uart_8250_port {
        const struct uart_8250_ops *ops;
 
        /* 8250 specific callbacks */
-       int                     (*dl_read)(struct uart_8250_port *);
-       void                    (*dl_write)(struct uart_8250_port *, int);
+       u32                     (*dl_read)(struct uart_8250_port *up);
+       void                    (*dl_write)(struct uart_8250_port *up, u32 value);
 
        struct uart_8250_em485 *em485;
        void                    (*rs485_start_tx)(struct uart_8250_port *);
@@ -183,8 +211,11 @@ void serial8250_set_isa_configurator(void (*v)(int port, struct uart_port *up,
                                               u32 *capabilities));
 
 #ifdef CONFIG_SERIAL_8250_RT288X
-unsigned int au_serial_in(struct uart_port *p, int offset);
-void au_serial_out(struct uart_port *p, int offset, int value);
+int rt288x_setup(struct uart_port *p);
+int au_platform_setup(struct plat_serial8250_port *p);
+#else
+static inline int rt288x_setup(struct uart_port *p) { return -ENODEV; }
+static inline int au_platform_setup(struct plat_serial8250_port *p) { return -ENODEV; }
 #endif
 
 #endif
index 66ecec1..6d58c57 100644 (file)
@@ -28,6 +28,7 @@
 
 struct uart_port;
 struct serial_struct;
+struct serial_port_device;
 struct device;
 struct gpio_desc;
 
@@ -458,6 +459,7 @@ struct uart_port {
                                                struct serial_rs485 *rs485);
        int                     (*iso7816_config)(struct uart_port *,
                                                  struct serial_iso7816 *iso7816);
+       int                     ctrl_id;                /* optional serial core controller id */
        unsigned int            irq;                    /* irq number */
        unsigned long           irqflags;               /* irq flags  */
        unsigned int            uartclk;                /* base uart clock */
@@ -563,7 +565,8 @@ struct uart_port {
        unsigned int            minor;
        resource_size_t         mapbase;                /* for ioremap */
        resource_size_t         mapsize;
-       struct device           *dev;                   /* parent device */
+       struct device           *dev;                   /* serial port physical parent device */
+       struct serial_port_device *port_dev;            /* serial core port device */
 
        unsigned long           sysrq;                  /* sysrq timeout */
        unsigned int            sysrq_ch;               /* char for sysrq */
@@ -853,7 +856,7 @@ void uart_console_write(struct uart_port *port, const char *s,
 int uart_register_driver(struct uart_driver *uart);
 void uart_unregister_driver(struct uart_driver *uart);
 int uart_add_one_port(struct uart_driver *reg, struct uart_port *port);
-int uart_remove_one_port(struct uart_driver *reg, struct uart_port *port);
+void uart_remove_one_port(struct uart_driver *reg, struct uart_port *port);
 bool uart_match_port(const struct uart_port *port1,
                const struct uart_port *port2);
 
index 6b456c5..666b56f 100644 (file)
@@ -87,6 +87,7 @@ TARGETS += timers
 endif
 TARGETS += tmpfs
 TARGETS += tpm2
+TARGETS += tty
 TARGETS += user
 TARGETS += vDSO
 TARGETS += mm
diff --git a/tools/testing/selftests/tty/.gitignore b/tools/testing/selftests/tty/.gitignore
new file mode 100644 (file)
index 0000000..fe70462
--- /dev/null
@@ -0,0 +1,2 @@
+# SPDX-License-Identifier: GPL-2.0-only
+tty_tstamp_update
diff --git a/tools/testing/selftests/tty/Makefile b/tools/testing/selftests/tty/Makefile
new file mode 100644 (file)
index 0000000..50d7027
--- /dev/null
@@ -0,0 +1,5 @@
+# SPDX-License-Identifier: GPL-2.0
+CFLAGS = -O2 -Wall
+TEST_GEN_PROGS := tty_tstamp_update
+
+include ../lib.mk
diff --git a/tools/testing/selftests/tty/tty_tstamp_update.c b/tools/testing/selftests/tty/tty_tstamp_update.c
new file mode 100644 (file)
index 0000000..0ee9794
--- /dev/null
@@ -0,0 +1,88 @@
+// SPDX-License-Identifier: GPL-2.0
+
+#include <errno.h>
+#include <stdbool.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/stat.h>
+#include <unistd.h>
+#include <linux/limits.h>
+
+#include "../kselftest.h"
+
+#define MIN_TTY_PATH_LEN 8
+
+static bool tty_valid(char *tty)
+{
+       if (strlen(tty) < MIN_TTY_PATH_LEN)
+               return false;
+
+       if (strncmp(tty, "/dev/tty", MIN_TTY_PATH_LEN) == 0 ||
+           strncmp(tty, "/dev/pts", MIN_TTY_PATH_LEN) == 0)
+               return true;
+
+       return false;
+}
+
+static int write_dev_tty(void)
+{
+       FILE *f;
+       int r = 0;
+
+       f = fopen("/dev/tty", "r+");
+       if (!f)
+               return -errno;
+
+       r = fprintf(f, "hello, world!\n");
+       if (r != strlen("hello, world!\n"))
+               r = -EIO;
+
+       fclose(f);
+       return r;
+}
+
+int main(int argc, char **argv)
+{
+       int r;
+       char tty[PATH_MAX] = {};
+       struct stat st1, st2;
+
+       ksft_print_header();
+       ksft_set_plan(1);
+
+       r = readlink("/proc/self/fd/0", tty, PATH_MAX);
+       if (r < 0)
+               ksft_exit_fail_msg("readlink on /proc/self/fd/0 failed: %m\n");
+
+       if (!tty_valid(tty))
+               ksft_exit_skip("invalid tty path '%s'\n", tty);
+
+       r = stat(tty, &st1);
+       if (r < 0)
+               ksft_exit_fail_msg("stat failed on tty path '%s': %m\n", tty);
+
+       /* We need to wait at least 8 seconds in order to observe timestamp change */
+       /* https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=fbf47635315ab308c9b58a1ea0906e711a9228de */
+       sleep(10);
+
+       r = write_dev_tty();
+       if (r < 0)
+               ksft_exit_fail_msg("failed to write to /dev/tty: %s\n",
+                                  strerror(-r));
+
+       r = stat(tty, &st2);
+       if (r < 0)
+               ksft_exit_fail_msg("stat failed on tty path '%s': %m\n", tty);
+
+       /* We wrote to the terminal so timestamps should have been updated */
+       if (st1.st_atim.tv_sec == st2.st_atim.tv_sec &&
+           st1.st_mtim.tv_sec == st2.st_mtim.tv_sec) {
+               ksft_test_result_fail("tty timestamps not updated\n");
+               ksft_exit_fail();
+       }
+
+       ksft_test_result_pass(
+               "timestamps of terminal '%s' updated after write to /dev/tty\n", tty);
+       return EXIT_SUCCESS;
+}