serial:st-asc: Add ST ASC driver.
authorSrinivas Kandagatla <srinivas.kandagatla@st.com>
Mon, 15 Jul 2013 11:39:23 +0000 (12:39 +0100)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Fri, 26 Jul 2013 23:08:02 +0000 (16:08 -0700)
This patch adds support to ASC (asynchronous serial controller)
driver, which is basically a standard serial driver. This IP is common
across all the ST parts for settop box platforms.

ASC is embedded in ST COMMS IP block. It supports Rx & Tx functionality.
It support all industry standard baud rates.

Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@st.com>
CC: Stephen Gallimore <stephen.gallimore@st.com>
CC: Stuart Menefy <stuart.menefy@st.com>
CC: Arnd Bergmann <arnd@arndb.de>
CC: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Documentation/devicetree/bindings/tty/serial/st-asc.txt [new file with mode: 0644]
drivers/tty/serial/Kconfig
drivers/tty/serial/Makefile
drivers/tty/serial/st-asc.c [new file with mode: 0644]
include/uapi/linux/serial_core.h

diff --git a/Documentation/devicetree/bindings/tty/serial/st-asc.txt b/Documentation/devicetree/bindings/tty/serial/st-asc.txt
new file mode 100644 (file)
index 0000000..75d877f
--- /dev/null
@@ -0,0 +1,18 @@
+*st-asc(Serial Port)
+
+Required properties:
+- compatible : Should be "st,asc".
+- reg, reg-names, interrupts, interrupt-names  : Standard way to define device
+                       resources with names. look in
+                       Documentation/devicetree/bindings/resource-names.txt
+
+Optional properties:
+- st,hw-flow-ctrl      bool flag to enable hardware flow control.
+- st,force-m1          bool flat to force asc to be in Mode-1 recommeded
+                       for high bit rates (above 19.2K)
+Example:
+serial@fe440000{
+    compatible    = "st,asc";
+    reg         = <0xfe440000 0x2c>;
+    interrupts     =  <0 209 0>;
+};
index 6e73781..bdf5c0e 100644 (file)
@@ -1497,6 +1497,22 @@ config SERIAL_FSL_LPUART_CONSOLE
          If you have enabled the lpuart serial port on the Freescale SoCs,
          you can make it the console by answering Y to this option.
 
+config SERIAL_ST_ASC
+       tristate "ST ASC serial port support"
+       select SERIAL_CORE
+       help
+         This driver is for the on-chip Asychronous Serial Controller on
+         STMicroelectronics STi SoCs.
+         ASC is embedded in ST COMMS IP block. It supports Rx & Tx functionality.
+         It support all industry standard baud rates.
+
+         If unsure, say N.
+
+config SERIAL_ST_ASC_CONSOLE
+       bool "Support for console on ST ASC"
+       depends on SERIAL_ST_ASC=y
+       select SERIAL_CORE_CONSOLE
+
 endmenu
 
 endif # TTY
index cf650f0..47b679c 100644 (file)
@@ -65,6 +65,7 @@ obj-$(CONFIG_SERIAL_KGDB_NMI) += kgdb_nmi.o
 obj-$(CONFIG_SERIAL_KS8695) += serial_ks8695.o
 obj-$(CONFIG_SERIAL_OMAP) += omap-serial.o
 obj-$(CONFIG_SERIAL_ALTERA_UART) += altera_uart.o
+obj-$(CONFIG_SERIAL_ST_ASC) += st-asc.o
 obj-$(CONFIG_KGDB_SERIAL_CONSOLE) += kgdboc.o
 obj-$(CONFIG_SERIAL_QE) += ucc_uart.o
 obj-$(CONFIG_SERIAL_TIMBERDALE)        += timbuart.o
diff --git a/drivers/tty/serial/st-asc.c b/drivers/tty/serial/st-asc.c
new file mode 100644 (file)
index 0000000..1838798
--- /dev/null
@@ -0,0 +1,937 @@
+/*
+ * st-asc.c: ST Asynchronous serial controller (ASC) driver
+ *
+ * Copyright (C) 2003-2013 STMicroelectronics (R&D) Limited
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ */
+
+#if defined(CONFIG_SERIAL_ST_ASC_CONSOLE) && defined(CONFIG_MAGIC_SYSRQ)
+#define SUPPORT_SYSRQ
+#endif
+
+#include <linux/module.h>
+#include <linux/serial.h>
+#include <linux/console.h>
+#include <linux/sysrq.h>
+#include <linux/platform_device.h>
+#include <linux/io.h>
+#include <linux/irq.h>
+#include <linux/tty.h>
+#include <linux/tty_flip.h>
+#include <linux/delay.h>
+#include <linux/spinlock.h>
+#include <linux/pm_runtime.h>
+#include <linux/of.h>
+#include <linux/of_platform.h>
+#include <linux/serial_core.h>
+#include <linux/clk.h>
+
+#define DRIVER_NAME "st-asc"
+#define ASC_SERIAL_NAME "ttyAS"
+#define ASC_FIFO_SIZE 16
+#define ASC_MAX_PORTS 8
+
+struct asc_port {
+       struct uart_port port;
+       struct clk *clk;
+       unsigned int hw_flow_control:1;
+       unsigned int force_m1:1;
+};
+
+static struct asc_port asc_ports[ASC_MAX_PORTS];
+static struct uart_driver asc_uart_driver;
+
+/*---- UART Register definitions ------------------------------*/
+
+/* Register offsets */
+
+#define ASC_BAUDRATE                   0x00
+#define ASC_TXBUF                      0x04
+#define ASC_RXBUF                      0x08
+#define ASC_CTL                                0x0C
+#define ASC_INTEN                      0x10
+#define ASC_STA                                0x14
+#define ASC_GUARDTIME                  0x18
+#define ASC_TIMEOUT                    0x1C
+#define ASC_TXRESET                    0x20
+#define ASC_RXRESET                    0x24
+#define ASC_RETRIES                    0x28
+
+/* ASC_RXBUF */
+#define ASC_RXBUF_PE                   0x100
+#define ASC_RXBUF_FE                   0x200
+/**
+ * Some of status comes from higher bits of the character and some come from
+ * the status register. Combining both of them in to single status using dummy
+ * bits.
+ */
+#define ASC_RXBUF_DUMMY_RX             0x10000
+#define ASC_RXBUF_DUMMY_BE             0x20000
+#define ASC_RXBUF_DUMMY_OE             0x40000
+
+/* ASC_CTL */
+
+#define ASC_CTL_MODE_MSK               0x0007
+#define  ASC_CTL_MODE_8BIT             0x0001
+#define  ASC_CTL_MODE_7BIT_PAR         0x0003
+#define  ASC_CTL_MODE_9BIT             0x0004
+#define  ASC_CTL_MODE_8BIT_WKUP                0x0005
+#define  ASC_CTL_MODE_8BIT_PAR         0x0007
+#define ASC_CTL_STOP_MSK               0x0018
+#define  ASC_CTL_STOP_HALFBIT          0x0000
+#define  ASC_CTL_STOP_1BIT             0x0008
+#define  ASC_CTL_STOP_1_HALFBIT                0x0010
+#define  ASC_CTL_STOP_2BIT             0x0018
+#define ASC_CTL_PARITYODD              0x0020
+#define ASC_CTL_LOOPBACK               0x0040
+#define ASC_CTL_RUN                    0x0080
+#define ASC_CTL_RXENABLE               0x0100
+#define ASC_CTL_SCENABLE               0x0200
+#define ASC_CTL_FIFOENABLE             0x0400
+#define ASC_CTL_CTSENABLE              0x0800
+#define ASC_CTL_BAUDMODE               0x1000
+
+/* ASC_GUARDTIME */
+
+#define ASC_GUARDTIME_MSK              0x00FF
+
+/* ASC_INTEN */
+
+#define ASC_INTEN_RBE                  0x0001
+#define ASC_INTEN_TE                   0x0002
+#define ASC_INTEN_THE                  0x0004
+#define ASC_INTEN_PE                   0x0008
+#define ASC_INTEN_FE                   0x0010
+#define ASC_INTEN_OE                   0x0020
+#define ASC_INTEN_TNE                  0x0040
+#define ASC_INTEN_TOI                  0x0080
+#define ASC_INTEN_RHF                  0x0100
+
+/* ASC_RETRIES */
+
+#define ASC_RETRIES_MSK                        0x00FF
+
+/* ASC_RXBUF */
+
+#define ASC_RXBUF_MSK                  0x03FF
+
+/* ASC_STA */
+
+#define ASC_STA_RBF                    0x0001
+#define ASC_STA_TE                     0x0002
+#define ASC_STA_THE                    0x0004
+#define ASC_STA_PE                     0x0008
+#define ASC_STA_FE                     0x0010
+#define ASC_STA_OE                     0x0020
+#define ASC_STA_TNE                    0x0040
+#define ASC_STA_TOI                    0x0080
+#define ASC_STA_RHF                    0x0100
+#define ASC_STA_TF                     0x0200
+#define ASC_STA_NKD                    0x0400
+
+/* ASC_TIMEOUT */
+
+#define ASC_TIMEOUT_MSK                        0x00FF
+
+/* ASC_TXBUF */
+
+#define ASC_TXBUF_MSK                  0x01FF
+
+/*---- Inline function definitions ---------------------------*/
+
+static inline struct asc_port *to_asc_port(struct uart_port *port)
+{
+       return container_of(port, struct asc_port, port);
+}
+
+static inline u32 asc_in(struct uart_port *port, u32 offset)
+{
+       return readl(port->membase + offset);
+}
+
+static inline void asc_out(struct uart_port *port, u32 offset, u32 value)
+{
+       writel(value, port->membase + offset);
+}
+
+/*
+ * Some simple utility functions to enable and disable interrupts.
+ * Note that these need to be called with interrupts disabled.
+ */
+static inline void asc_disable_tx_interrupts(struct uart_port *port)
+{
+       u32 intenable = asc_in(port, ASC_INTEN) & ~ASC_INTEN_THE;
+       asc_out(port, ASC_INTEN, intenable);
+       (void)asc_in(port, ASC_INTEN);  /* Defeat bus write posting */
+}
+
+static inline void asc_enable_tx_interrupts(struct uart_port *port)
+{
+       u32 intenable = asc_in(port, ASC_INTEN) | ASC_INTEN_THE;
+       asc_out(port, ASC_INTEN, intenable);
+}
+
+static inline void asc_disable_rx_interrupts(struct uart_port *port)
+{
+       u32 intenable = asc_in(port, ASC_INTEN) & ~ASC_INTEN_RBE;
+       asc_out(port, ASC_INTEN, intenable);
+       (void)asc_in(port, ASC_INTEN);  /* Defeat bus write posting */
+}
+
+static inline void asc_enable_rx_interrupts(struct uart_port *port)
+{
+       u32 intenable = asc_in(port, ASC_INTEN) | ASC_INTEN_RBE;
+       asc_out(port, ASC_INTEN, intenable);
+}
+
+static inline u32 asc_txfifo_is_empty(struct uart_port *port)
+{
+       return asc_in(port, ASC_STA) & ASC_STA_TE;
+}
+
+static inline int asc_txfifo_is_full(struct uart_port *port)
+{
+       return asc_in(port, ASC_STA) & ASC_STA_TF;
+}
+
+static inline const char *asc_port_name(struct uart_port *port)
+{
+       return to_platform_device(port->dev)->name;
+}
+
+/*----------------------------------------------------------------------*/
+
+/*
+ * This section contains code to support the use of the ASC as a
+ * generic serial port.
+ */
+
+static inline unsigned asc_hw_txroom(struct uart_port *port)
+{
+       u32 status = asc_in(port, ASC_STA);
+
+       if (status & ASC_STA_THE)
+               return port->fifosize / 2;
+       else if (!(status & ASC_STA_TF))
+               return 1;
+
+       return 0;
+}
+
+/*
+ * Start transmitting chars.
+ * This is called from both interrupt and task level.
+ * Either way interrupts are disabled.
+ */
+static void asc_transmit_chars(struct uart_port *port)
+{
+       struct circ_buf *xmit = &port->state->xmit;
+       int txroom;
+       unsigned char c;
+
+       txroom = asc_hw_txroom(port);
+
+       if ((txroom != 0) && port->x_char) {
+               c = port->x_char;
+               port->x_char = 0;
+               asc_out(port, ASC_TXBUF, c);
+               port->icount.tx++;
+               txroom = asc_hw_txroom(port);
+       }
+
+       if (uart_tx_stopped(port)) {
+               /*
+                * We should try and stop the hardware here, but I
+                * don't think the ASC has any way to do that.
+                */
+               asc_disable_tx_interrupts(port);
+               return;
+       }
+
+       if (uart_circ_empty(xmit)) {
+               asc_disable_tx_interrupts(port);
+               return;
+       }
+
+       if (txroom == 0)
+               return;
+
+       do {
+               c = xmit->buf[xmit->tail];
+               xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
+               asc_out(port, ASC_TXBUF, c);
+               port->icount.tx++;
+               txroom--;
+       } while ((txroom > 0) && (!uart_circ_empty(xmit)));
+
+       if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
+               uart_write_wakeup(port);
+
+       if (uart_circ_empty(xmit))
+               asc_disable_tx_interrupts(port);
+}
+
+static void asc_receive_chars(struct uart_port *port)
+{
+       struct tty_port *tport = &port->state->port;
+       unsigned long status;
+       unsigned long c = 0;
+       char flag;
+
+       if (port->irq_wake)
+               pm_wakeup_event(tport->tty->dev, 0);
+
+       while ((status = asc_in(port, ASC_STA)) & ASC_STA_RBF) {
+               c = asc_in(port, ASC_RXBUF) | ASC_RXBUF_DUMMY_RX;
+               flag = TTY_NORMAL;
+               port->icount.rx++;
+
+               if ((c & (ASC_RXBUF_FE | ASC_RXBUF_PE)) ||
+                       status & ASC_STA_OE) {
+
+                       if (c & ASC_RXBUF_FE) {
+                               if (c == ASC_RXBUF_FE) {
+                                       port->icount.brk++;
+                                       if (uart_handle_break(port))
+                                               continue;
+                                       c |= ASC_RXBUF_DUMMY_BE;
+                               } else {
+                                       port->icount.frame++;
+                               }
+                       } else if (c & ASC_RXBUF_PE) {
+                               port->icount.parity++;
+                       }
+                       /*
+                        * Reading any data from the RX FIFO clears the
+                        * overflow error condition.
+                        */
+                       if (status & ASC_STA_OE) {
+                               port->icount.overrun++;
+                               c |= ASC_RXBUF_DUMMY_OE;
+                       }
+
+                       c &= port->read_status_mask;
+
+                       if (c & ASC_RXBUF_DUMMY_BE)
+                               flag = TTY_BREAK;
+                       else if (c & ASC_RXBUF_PE)
+                               flag = TTY_PARITY;
+                       else if (c & ASC_RXBUF_FE)
+                               flag = TTY_FRAME;
+               }
+
+               if (uart_handle_sysrq_char(port, c))
+                       continue;
+
+               uart_insert_char(port, c, ASC_RXBUF_DUMMY_OE, c & 0xff, flag);
+       }
+
+       /* Tell the rest of the system the news. New characters! */
+       tty_flip_buffer_push(tport);
+}
+
+static irqreturn_t asc_interrupt(int irq, void *ptr)
+{
+       struct uart_port *port = ptr;
+       u32 status;
+
+       spin_lock(&port->lock);
+
+       status = asc_in(port, ASC_STA);
+
+       if (status & ASC_STA_RBF) {
+               /* Receive FIFO not empty */
+               asc_receive_chars(port);
+       }
+
+       if ((status & ASC_STA_THE) &&
+           (asc_in(port, ASC_INTEN) & ASC_INTEN_THE)) {
+               /* Transmitter FIFO at least half empty */
+               asc_transmit_chars(port);
+       }
+
+       spin_unlock(&port->lock);
+
+       return IRQ_HANDLED;
+}
+
+/*----------------------------------------------------------------------*/
+
+/*
+ * UART Functions
+ */
+
+static unsigned int asc_tx_empty(struct uart_port *port)
+{
+       return asc_txfifo_is_empty(port) ? TIOCSER_TEMT : 0;
+}
+
+static void asc_set_mctrl(struct uart_port *port, unsigned int mctrl)
+{
+       /*
+        * This routine is used for seting signals of: DTR, DCD, CTS/RTS
+        * We use ASC's hardware for CTS/RTS, so don't need any for that.
+        * Some boards have DTR and DCD implemented using PIO pins,
+        * code to do this should be hooked in here.
+        */
+}
+
+static unsigned int asc_get_mctrl(struct uart_port *port)
+{
+       /*
+        * This routine is used for geting signals of: DTR, DCD, DSR, RI,
+        * and CTS/RTS
+        */
+       return TIOCM_CAR | TIOCM_DSR | TIOCM_CTS;
+}
+
+/* There are probably characters waiting to be transmitted. */
+static void asc_start_tx(struct uart_port *port)
+{
+       struct circ_buf *xmit = &port->state->xmit;
+
+       if (!uart_circ_empty(xmit))
+               asc_enable_tx_interrupts(port);
+}
+
+/* Transmit stop */
+static void asc_stop_tx(struct uart_port *port)
+{
+       asc_disable_tx_interrupts(port);
+}
+
+/* Receive stop */
+static void asc_stop_rx(struct uart_port *port)
+{
+       asc_disable_rx_interrupts(port);
+}
+
+/* Force modem status interrupts on */
+static void asc_enable_ms(struct uart_port *port)
+{
+       /* Nothing here yet .. */
+}
+
+/* Handle breaks - ignored by us */
+static void asc_break_ctl(struct uart_port *port, int break_state)
+{
+       /* Nothing here yet .. */
+}
+
+/*
+ * Enable port for reception.
+ */
+static int asc_startup(struct uart_port *port)
+{
+       if (request_irq(port->irq, asc_interrupt, IRQF_NO_SUSPEND,
+                       asc_port_name(port), port)) {
+               dev_err(port->dev, "cannot allocate irq.\n");
+               return -ENODEV;
+       }
+
+       asc_transmit_chars(port);
+       asc_enable_rx_interrupts(port);
+
+       return 0;
+}
+
+static void asc_shutdown(struct uart_port *port)
+{
+       asc_disable_tx_interrupts(port);
+       asc_disable_rx_interrupts(port);
+       free_irq(port->irq, port);
+}
+
+static void asc_pm(struct uart_port *port, unsigned int state,
+               unsigned int oldstate)
+{
+       struct asc_port *ascport = to_asc_port(port);
+       unsigned long flags = 0;
+       u32 ctl;
+
+       switch (state) {
+       case UART_PM_STATE_ON:
+               clk_prepare_enable(ascport->clk);
+               break;
+       case UART_PM_STATE_OFF:
+               /*
+                * Disable the ASC baud rate generator, which is as close as
+                * we can come to turning it off. Note this is not called with
+                * the port spinlock held.
+                */
+               spin_lock_irqsave(&port->lock, flags);
+               ctl = asc_in(port, ASC_CTL) & ~ASC_CTL_RUN;
+               asc_out(port, ASC_CTL, ctl);
+               spin_unlock_irqrestore(&port->lock, flags);
+               clk_disable_unprepare(ascport->clk);
+               break;
+       }
+}
+
+static void asc_set_termios(struct uart_port *port, struct ktermios *termios,
+                           struct ktermios *old)
+{
+       struct asc_port *ascport = to_asc_port(port);
+       unsigned int baud;
+       u32 ctrl_val;
+       tcflag_t cflag;
+       unsigned long flags;
+
+       /* Update termios to reflect hardware capabilities */
+       termios->c_cflag &= ~(CMSPAR |
+                        (ascport->hw_flow_control ? 0 : CRTSCTS));
+
+       port->uartclk = clk_get_rate(ascport->clk);
+
+       baud = uart_get_baud_rate(port, termios, old, 0, port->uartclk/16);
+       cflag = termios->c_cflag;
+
+       spin_lock_irqsave(&port->lock, flags);
+
+       /* read control register */
+       ctrl_val = asc_in(port, ASC_CTL);
+
+       /* stop serial port and reset value */
+       asc_out(port, ASC_CTL, (ctrl_val & ~ASC_CTL_RUN));
+       ctrl_val = ASC_CTL_RXENABLE | ASC_CTL_FIFOENABLE;
+
+       /* reset fifo rx & tx */
+       asc_out(port, ASC_TXRESET, 1);
+       asc_out(port, ASC_RXRESET, 1);
+
+       /* set character length */
+       if ((cflag & CSIZE) == CS7) {
+               ctrl_val |= ASC_CTL_MODE_7BIT_PAR;
+       } else {
+               ctrl_val |= (cflag & PARENB) ?  ASC_CTL_MODE_8BIT_PAR :
+                                               ASC_CTL_MODE_8BIT;
+       }
+
+       /* set stop bit */
+       ctrl_val |= (cflag & CSTOPB) ? ASC_CTL_STOP_2BIT : ASC_CTL_STOP_1BIT;
+
+       /* odd parity */
+       if (cflag & PARODD)
+               ctrl_val |= ASC_CTL_PARITYODD;
+
+       /* hardware flow control */
+       if ((cflag & CRTSCTS))
+               ctrl_val |= ASC_CTL_CTSENABLE;
+
+       if ((baud < 19200) && !ascport->force_m1) {
+               asc_out(port, ASC_BAUDRATE, (port->uartclk / (16 * baud)));
+       } else {
+               /*
+                * MODE 1: recommended for high bit rates (above 19.2K)
+                *
+                *                   baudrate * 16 * 2^16
+                * ASCBaudRate =   ------------------------
+                *                          inputclock
+                *
+                * However to keep the maths inside 32bits we divide top and
+                * bottom by 64. The +1 is to avoid a divide by zero if the
+                * input clock rate is something unexpected.
+                */
+               u32 counter = (baud * 16384) / ((port->uartclk / 64) + 1);
+               asc_out(port, ASC_BAUDRATE, counter);
+               ctrl_val |= ASC_CTL_BAUDMODE;
+       }
+
+       uart_update_timeout(port, cflag, baud);
+
+       ascport->port.read_status_mask = ASC_RXBUF_DUMMY_OE;
+       if (termios->c_iflag & INPCK)
+               ascport->port.read_status_mask |= ASC_RXBUF_FE | ASC_RXBUF_PE;
+       if (termios->c_iflag & (BRKINT | PARMRK))
+               ascport->port.read_status_mask |= ASC_RXBUF_DUMMY_BE;
+
+       /*
+        * Characters to ignore
+        */
+       ascport->port.ignore_status_mask = 0;
+       if (termios->c_iflag & IGNPAR)
+               ascport->port.ignore_status_mask |= ASC_RXBUF_FE | ASC_RXBUF_PE;
+       if (termios->c_iflag & IGNBRK) {
+               ascport->port.ignore_status_mask |= ASC_RXBUF_DUMMY_BE;
+               /*
+                * If we're ignoring parity and break indicators,
+                * ignore overruns too (for real raw support).
+                */
+               if (termios->c_iflag & IGNPAR)
+                       ascport->port.ignore_status_mask |= ASC_RXBUF_DUMMY_OE;
+       }
+
+       /*
+        * Ignore all characters if CREAD is not set.
+        */
+       if (!(termios->c_cflag & CREAD))
+               ascport->port.ignore_status_mask |= ASC_RXBUF_DUMMY_RX;
+
+       /* Set the timeout */
+       asc_out(port, ASC_TIMEOUT, 20);
+
+       /* write final value and enable port */
+       asc_out(port, ASC_CTL, (ctrl_val | ASC_CTL_RUN));
+
+       spin_unlock_irqrestore(&port->lock, flags);
+}
+
+static const char *asc_type(struct uart_port *port)
+{
+       return (port->type == PORT_ASC) ? DRIVER_NAME : NULL;
+}
+
+static void asc_release_port(struct uart_port *port)
+{
+}
+
+static int asc_request_port(struct uart_port *port)
+{
+       return 0;
+}
+
+/*
+ * Called when the port is opened, and UPF_BOOT_AUTOCONF flag is set
+ * Set type field if successful
+ */
+static void asc_config_port(struct uart_port *port, int flags)
+{
+       if ((flags & UART_CONFIG_TYPE))
+               port->type = PORT_ASC;
+}
+
+static int
+asc_verify_port(struct uart_port *port, struct serial_struct *ser)
+{
+       /* No user changeable parameters */
+       return -EINVAL;
+}
+
+#ifdef CONFIG_CONSOLE_POLL
+/*
+ * Console polling routines for writing and reading from the uart while
+ * in an interrupt or debug context (i.e. kgdb).
+ */
+
+static int asc_get_poll_char(struct uart_port *port)
+{
+       if (!(asc_in(port, ASC_STA) & ASC_STA_RBF))
+               return NO_POLL_CHAR;
+
+       return asc_in(port, ASC_RXBUF);
+}
+
+static void asc_put_poll_char(struct uart_port *port, unsigned char c)
+{
+       while (asc_txfifo_is_full(port))
+               cpu_relax();
+       asc_out(port, ASC_TXBUF, c);
+}
+
+#endif /* CONFIG_CONSOLE_POLL */
+
+/*---------------------------------------------------------------------*/
+
+static struct uart_ops asc_uart_ops = {
+       .tx_empty       = asc_tx_empty,
+       .set_mctrl      = asc_set_mctrl,
+       .get_mctrl      = asc_get_mctrl,
+       .start_tx       = asc_start_tx,
+       .stop_tx        = asc_stop_tx,
+       .stop_rx        = asc_stop_rx,
+       .enable_ms      = asc_enable_ms,
+       .break_ctl      = asc_break_ctl,
+       .startup        = asc_startup,
+       .shutdown       = asc_shutdown,
+       .set_termios    = asc_set_termios,
+       .type           = asc_type,
+       .release_port   = asc_release_port,
+       .request_port   = asc_request_port,
+       .config_port    = asc_config_port,
+       .verify_port    = asc_verify_port,
+       .pm             = asc_pm,
+#ifdef CONFIG_CONSOLE_POLL
+       .poll_get_char = asc_get_poll_char,
+       .poll_put_char = asc_put_poll_char,
+#endif /* CONFIG_CONSOLE_POLL */
+};
+
+static int asc_init_port(struct asc_port *ascport,
+                         struct platform_device *pdev)
+{
+       struct uart_port *port = &ascport->port;
+       struct resource *res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+
+       if (!res) {
+               dev_err(&pdev->dev, "Unable to get io resource\n");
+               return -ENODEV;
+       }
+
+       port->iotype    = UPIO_MEM;
+       port->flags     = UPF_BOOT_AUTOCONF;
+       port->ops       = &asc_uart_ops;
+       port->fifosize  = ASC_FIFO_SIZE;
+       port->dev       = &pdev->dev;
+       port->mapbase   = res->start;
+       port->irq       = platform_get_irq(pdev, 0);
+
+       port->membase = devm_request_and_ioremap(&pdev->dev, res);
+       if (!port->membase) {
+               dev_err(&pdev->dev, "Unable to request io memory\n");
+               return -ENODEV;
+       }
+
+       spin_lock_init(&port->lock);
+
+       ascport->clk = devm_clk_get(&pdev->dev, NULL);
+
+       if (WARN_ON(IS_ERR(ascport->clk)))
+               return -EINVAL;
+       /* ensure that clk rate is correct by enabling the clk */
+       clk_prepare_enable(ascport->clk);
+       ascport->port.uartclk = clk_get_rate(ascport->clk);
+       WARN_ON(ascport->port.uartclk == 0);
+       clk_disable_unprepare(ascport->clk);
+
+       return 0;
+}
+
+static struct asc_port *asc_of_get_asc_port(struct platform_device *pdev)
+{
+       struct device_node *np = pdev->dev.of_node;
+       int id;
+
+       if (!np)
+               return NULL;
+
+       id = of_alias_get_id(np, ASC_SERIAL_NAME);
+
+       if (id < 0)
+               id = 0;
+
+       if (WARN_ON(id >= ASC_MAX_PORTS))
+               return NULL;
+
+       asc_ports[id].hw_flow_control = of_property_read_bool(np,
+                                                       "st,hw-flow-control");
+       asc_ports[id].force_m1 =  of_property_read_bool(np, "st,force_m1");
+       asc_ports[id].port.line = id;
+       return &asc_ports[id];
+}
+
+static struct of_device_id asc_match[] = {
+       { .compatible = "st,asc", },
+       {},
+};
+
+MODULE_DEVICE_TABLE(of, asc_match);
+
+static int asc_serial_probe(struct platform_device *pdev)
+{
+       int ret;
+       struct asc_port *ascport;
+
+       ascport = asc_of_get_asc_port(pdev);
+       if (!ascport)
+               return -ENODEV;
+
+       ret = asc_init_port(ascport, pdev);
+       if (ret)
+               return ret;
+
+       ret = uart_add_one_port(&asc_uart_driver, &ascport->port);
+       if (ret)
+               return ret;
+
+       platform_set_drvdata(pdev, &ascport->port);
+
+       return 0;
+}
+
+static int asc_serial_remove(struct platform_device *pdev)
+{
+       struct uart_port *port = platform_get_drvdata(pdev);
+
+       platform_set_drvdata(pdev, NULL);
+       return uart_remove_one_port(&asc_uart_driver, port);
+}
+
+#ifdef CONFIG_PM_SLEEP
+static int asc_serial_suspend(struct device *dev)
+{
+       struct platform_device *pdev = to_platform_device(dev);
+       struct uart_port *port = platform_get_drvdata(pdev);
+
+       return uart_suspend_port(&asc_uart_driver, port);
+}
+
+static int asc_serial_resume(struct device *dev)
+{
+       struct platform_device *pdev = to_platform_device(dev);
+       struct uart_port *port = platform_get_drvdata(pdev);
+
+       return uart_resume_port(&asc_uart_driver, port);
+}
+
+#endif /* CONFIG_PM_SLEEP */
+
+/*----------------------------------------------------------------------*/
+
+#ifdef CONFIG_SERIAL_ST_ASC_CONSOLE
+static void asc_console_putchar(struct uart_port *port, int ch)
+{
+       unsigned int timeout = 1000000;
+
+       /* Wait for upto 1 second in case flow control is stopping us. */
+       while (--timeout && asc_txfifo_is_full(port))
+               udelay(1);
+
+       asc_out(port, ASC_TXBUF, ch);
+}
+
+/*
+ *  Print a string to the serial port trying not to disturb
+ *  any possible real use of the port...
+ */
+
+static void asc_console_write(struct console *co, const char *s, unsigned count)
+{
+       struct uart_port *port = &asc_ports[co->index].port;
+       unsigned long flags;
+       unsigned long timeout = 1000000;
+       int locked = 1;
+       u32 intenable;
+
+       local_irq_save(flags);
+       if (port->sysrq)
+               locked = 0; /* asc_interrupt has already claimed the lock */
+       else if (oops_in_progress)
+               locked = spin_trylock(&port->lock);
+       else
+               spin_lock(&port->lock);
+
+       /*
+        * Disable interrupts so we don't get the IRQ line bouncing
+        * up and down while interrupts are disabled.
+        */
+       intenable = asc_in(port, ASC_INTEN);
+       asc_out(port, ASC_INTEN, 0);
+       (void)asc_in(port, ASC_INTEN);  /* Defeat bus write posting */
+
+       uart_console_write(port, s, count, asc_console_putchar);
+
+       while (--timeout && !asc_txfifo_is_empty(port))
+               udelay(1);
+
+       asc_out(port, ASC_INTEN, intenable);
+
+       if (locked)
+               spin_unlock(&port->lock);
+       local_irq_restore(flags);
+}
+
+static int asc_console_setup(struct console *co, char *options)
+{
+       struct asc_port *ascport;
+       int baud = 9600;
+       int bits = 8;
+       int parity = 'n';
+       int flow = 'n';
+
+       if (co->index >= ASC_MAX_PORTS)
+               return -ENODEV;
+
+       ascport = &asc_ports[co->index];
+
+       /*
+        * This driver does not support early console initialization
+        * (use ARM early printk support instead), so we only expect
+        * this to be called during the uart port registration when the
+        * driver gets probed and the port should be mapped at that point.
+        */
+       BUG_ON(ascport->port.mapbase == 0 || ascport->port.membase == NULL);
+
+       if (options)
+               uart_parse_options(options, &baud, &parity, &bits, &flow);
+
+       return uart_set_options(&ascport->port, co, baud, parity, bits, flow);
+}
+
+static struct console asc_console = {
+       .name           = ASC_SERIAL_NAME,
+       .device         = uart_console_device,
+       .write          = asc_console_write,
+       .setup          = asc_console_setup,
+       .flags          = CON_PRINTBUFFER,
+       .index          = -1,
+       .data           = &asc_uart_driver,
+};
+
+#define ASC_SERIAL_CONSOLE (&asc_console)
+
+#else
+#define ASC_SERIAL_CONSOLE NULL
+#endif /* CONFIG_SERIAL_ST_ASC_CONSOLE */
+
+static struct uart_driver asc_uart_driver = {
+       .owner          = THIS_MODULE,
+       .driver_name    = DRIVER_NAME,
+       .dev_name       = ASC_SERIAL_NAME,
+       .major          = 0,
+       .minor          = 0,
+       .nr             = ASC_MAX_PORTS,
+       .cons           = ASC_SERIAL_CONSOLE,
+};
+
+static const struct dev_pm_ops asc_serial_pm_ops = {
+       SET_SYSTEM_SLEEP_PM_OPS(asc_serial_suspend, asc_serial_resume)
+};
+
+static struct platform_driver asc_serial_driver = {
+       .probe          = asc_serial_probe,
+       .remove         = asc_serial_remove,
+       .driver = {
+               .name   = DRIVER_NAME,
+               .pm     = &asc_serial_pm_ops,
+               .owner  = THIS_MODULE,
+               .of_match_table = of_match_ptr(asc_match),
+       },
+};
+
+static int __init asc_init(void)
+{
+       int ret;
+       static char banner[] __initdata =
+               KERN_INFO "STMicroelectronics ASC driver initialized\n";
+
+       printk(banner);
+
+       ret = uart_register_driver(&asc_uart_driver);
+       if (ret)
+               return ret;
+
+       ret = platform_driver_register(&asc_serial_driver);
+       if (ret)
+               uart_unregister_driver(&asc_uart_driver);
+
+       return ret;
+}
+
+static void __exit asc_exit(void)
+{
+       platform_driver_unregister(&asc_serial_driver);
+       uart_unregister_driver(&asc_uart_driver);
+}
+
+module_init(asc_init);
+module_exit(asc_exit);
+
+MODULE_ALIAS("platform:" DRIVER_NAME);
+MODULE_AUTHOR("STMicroelectronics (R&D) Limited");
+MODULE_DESCRIPTION("STMicroelectronics ASC serial port driver");
+MODULE_LICENSE("GPL");
index 9119cc0..e40ebe1 100644 (file)
 /* SH-SCI */
 #define PORT_HSCIF     104
 
+/* ST ASC type numbers */
+#define PORT_ASC       105
+
 #endif /* _UAPILINUX_SERIAL_CORE_H */