From bd94c4077a0b2ecc35562c294f80f3659ecd8499 Mon Sep 17 00:00:00 2001 From: Masahiro Yamada Date: Wed, 28 Oct 2015 12:46:05 +0900 Subject: [PATCH] serial: support 16-bit register interface for console Currently, 8-bit (MMIO) and 32-bit (MMIO32) register interfaces are supported for the 8250 console, but the 16-bit (MMIO16) is not. The 8250 UART device on my board is connected to a 16-bit bus and my main motivation is to use earlycon with it. (Refer to arch/arm/boot/dts/uniphier-support-card.dtsi) Signed-off-by: Masahiro Yamada Reviewed-by: Peter Hurley Signed-off-by: Greg Kroah-Hartman --- Documentation/kernel-parameters.txt | 9 +++++---- drivers/tty/serial/8250/8250_core.c | 7 ++++--- drivers/tty/serial/8250/8250_early.c | 5 +++++ drivers/tty/serial/8250/8250_port.c | 20 ++++++++++++++++++++ drivers/tty/serial/earlycon.c | 15 +++++++++++---- drivers/tty/serial/of_serial.c | 3 +++ drivers/tty/serial/serial_core.c | 9 +++++++-- include/linux/serial_core.h | 1 + include/uapi/linux/serial.h | 1 + 9 files changed, 57 insertions(+), 13 deletions(-) diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt index 742f69d..054e11d 100644 --- a/Documentation/kernel-parameters.txt +++ b/Documentation/kernel-parameters.txt @@ -721,16 +721,17 @@ bytes respectively. Such letter suffixes can also be entirely omitted. uart[8250],io,[,options] uart[8250],mmio,[,options] + uart[8250],mmio16,[,options] uart[8250],mmio32,[,options] uart[8250],0x[,options] Start an early, polled-mode console on the 8250/16550 UART at the specified I/O port or MMIO address, switching to the matching ttyS device later. MMIO inter-register address stride is either 8-bit - (mmio) or 32-bit (mmio32). - If none of [io|mmio|mmio32], is assumed to be - equivalent to 'mmio'. 'options' are specified in the - same format described for ttyS above; if unspecified, + (mmio), 16-bit (mmio16), or 32-bit (mmio32). + If none of [io|mmio|mmio16|mmio32], is assumed + to be equivalent to 'mmio'. 'options' are specified in + the same format described for ttyS above; if unspecified, the h/w is not re-initialized. hvc Use the hypervisor console device . This is for diff --git a/drivers/tty/serial/8250/8250_core.c b/drivers/tty/serial/8250/8250_core.c index 3912646..c9720a9 100644 --- a/drivers/tty/serial/8250/8250_core.c +++ b/drivers/tty/serial/8250/8250_core.c @@ -620,7 +620,7 @@ static int univ8250_console_setup(struct console *co, char *options) * @options: ptr to option string from console command line * * Only attempts to match console command lines of the form: - * console=uart[8250],io|mmio|mmio32,[,] + * console=uart[8250],io|mmio|mmio16|mmio32,[,] * console=uart[8250],0x[,] * This form is used to register an initial earlycon boot console and * replace it with the serial8250_console at 8250 driver init. @@ -650,8 +650,9 @@ static int univ8250_console_match(struct console *co, char *name, int idx, if (port->iotype != iotype) continue; - if ((iotype == UPIO_MEM || iotype == UPIO_MEM32) && - (port->mapbase != addr)) + if ((iotype == UPIO_MEM || iotype == UPIO_MEM16 || + iotype == UPIO_MEM32 || iotype == UPIO_MEM32BE) + && (port->mapbase != addr)) continue; if (iotype == UPIO_PORT && port->iobase != addr) continue; diff --git a/drivers/tty/serial/8250/8250_early.c b/drivers/tty/serial/8250/8250_early.c index ca16195..af62131 100644 --- a/drivers/tty/serial/8250/8250_early.c +++ b/drivers/tty/serial/8250/8250_early.c @@ -42,6 +42,8 @@ static unsigned int __init serial8250_early_in(struct uart_port *port, int offse switch (port->iotype) { case UPIO_MEM: return readb(port->membase + offset); + case UPIO_MEM16: + return readw(port->membase + (offset << 1)); case UPIO_MEM32: return readl(port->membase + (offset << 2)); case UPIO_MEM32BE: @@ -59,6 +61,9 @@ static void __init serial8250_early_out(struct uart_port *port, int offset, int case UPIO_MEM: writeb(value, port->membase + offset); break; + case UPIO_MEM16: + writew(value, port->membase + (offset << 1)); + break; case UPIO_MEM32: writel(value, port->membase + (offset << 2)); break; diff --git a/drivers/tty/serial/8250/8250_port.c b/drivers/tty/serial/8250/8250_port.c index 52d82d2..8d262bc 100644 --- a/drivers/tty/serial/8250/8250_port.c +++ b/drivers/tty/serial/8250/8250_port.c @@ -368,6 +368,18 @@ static void mem_serial_out(struct uart_port *p, int offset, int value) writeb(value, p->membase + offset); } +static void mem16_serial_out(struct uart_port *p, int offset, int value) +{ + offset = offset << p->regshift; + writew(value, p->membase + offset); +} + +static unsigned int mem16_serial_in(struct uart_port *p, int offset) +{ + offset = offset << p->regshift; + return readw(p->membase + offset); +} + static void mem32_serial_out(struct uart_port *p, int offset, int value) { offset = offset << p->regshift; @@ -425,6 +437,11 @@ static void set_io_from_upio(struct uart_port *p) p->serial_out = mem_serial_out; break; + case UPIO_MEM16: + p->serial_in = mem16_serial_in; + p->serial_out = mem16_serial_out; + break; + case UPIO_MEM32: p->serial_in = mem32_serial_in; p->serial_out = mem32_serial_out; @@ -459,6 +476,7 @@ serial_port_out_sync(struct uart_port *p, int offset, int value) { switch (p->iotype) { case UPIO_MEM: + case UPIO_MEM16: case UPIO_MEM32: case UPIO_MEM32BE: case UPIO_AU: @@ -2462,6 +2480,7 @@ static int serial8250_request_std_resource(struct uart_8250_port *up) case UPIO_TSI: case UPIO_MEM32: case UPIO_MEM32BE: + case UPIO_MEM16: case UPIO_MEM: if (!port->mapbase) break; @@ -2499,6 +2518,7 @@ static void serial8250_release_std_resource(struct uart_8250_port *up) case UPIO_TSI: case UPIO_MEM32: case UPIO_MEM32BE: + case UPIO_MEM16: case UPIO_MEM: if (!port->mapbase) break; diff --git a/drivers/tty/serial/earlycon.c b/drivers/tty/serial/earlycon.c index f096360..07f7393 100644 --- a/drivers/tty/serial/earlycon.c +++ b/drivers/tty/serial/earlycon.c @@ -71,10 +71,16 @@ static int __init parse_options(struct earlycon_device *device, char *options) return -EINVAL; switch (port->iotype) { + case UPIO_MEM: + port->mapbase = addr; + break; + case UPIO_MEM16: + port->regshift = 1; + port->mapbase = addr; + break; case UPIO_MEM32: case UPIO_MEM32BE: - port->regshift = 2; /* fall-through */ - case UPIO_MEM: + port->regshift = 2; port->mapbase = addr; break; case UPIO_PORT: @@ -91,10 +97,11 @@ static int __init parse_options(struct earlycon_device *device, char *options) strlcpy(device->options, options, length); } - if (port->iotype == UPIO_MEM || port->iotype == UPIO_MEM32 || - port->iotype == UPIO_MEM32BE) + if (port->iotype == UPIO_MEM || port->iotype == UPIO_MEM16 || + port->iotype == UPIO_MEM32 || port->iotype == UPIO_MEM32BE) pr_info("Early serial console at MMIO%s 0x%llx (options '%s')\n", (port->iotype == UPIO_MEM) ? "" : + (port->iotype == UPIO_MEM16) ? "16" : (port->iotype == UPIO_MEM32) ? "32" : "32be", (unsigned long long)port->mapbase, device->options); diff --git a/drivers/tty/serial/of_serial.c b/drivers/tty/serial/of_serial.c index de50296..6d002ee 100644 --- a/drivers/tty/serial/of_serial.c +++ b/drivers/tty/serial/of_serial.c @@ -122,6 +122,9 @@ static int of_platform_serial_setup(struct platform_device *ofdev, case 1: port->iotype = UPIO_MEM; break; + case 2: + port->iotype = UPIO_MEM16; + break; case 4: port->iotype = of_device_is_big_endian(np) ? UPIO_MEM32BE : UPIO_MEM32; diff --git a/drivers/tty/serial/serial_core.c b/drivers/tty/serial/serial_core.c index 22cfc32..b1f54ab 100644 --- a/drivers/tty/serial/serial_core.c +++ b/drivers/tty/serial/serial_core.c @@ -1818,8 +1818,8 @@ uart_get_console(struct uart_port *ports, int nr, struct console *co) * @options: ptr for field; NULL if not present (out) * * Decodes earlycon kernel command line parameters of the form - * earlycon=,io|mmio|mmio32|mmio32be|mmio32native,, - * console=,io|mmio|mmio32|mmio32be|mmio32native,, + * earlycon=,io|mmio|mmio16|mmio32|mmio32be|mmio32native,, + * console=,io|mmio|mmio16|mmio32|mmio32be|mmio32native,, * * The optional form * earlycon=,0x, @@ -1834,6 +1834,9 @@ int uart_parse_earlycon(char *p, unsigned char *iotype, unsigned long *addr, if (strncmp(p, "mmio,", 5) == 0) { *iotype = UPIO_MEM; p += 5; + } else if (strncmp(p, "mmio16,", 7) == 0) { + *iotype = UPIO_MEM16; + p += 7; } else if (strncmp(p, "mmio32,", 7) == 0) { *iotype = UPIO_MEM32; p += 7; @@ -2186,6 +2189,7 @@ uart_report_port(struct uart_driver *drv, struct uart_port *port) "I/O 0x%lx offset 0x%x", port->iobase, port->hub6); break; case UPIO_MEM: + case UPIO_MEM16: case UPIO_MEM32: case UPIO_MEM32BE: case UPIO_AU: @@ -2831,6 +2835,7 @@ int uart_match_port(struct uart_port *port1, struct uart_port *port2) return (port1->iobase == port2->iobase) && (port1->hub6 == port2->hub6); case UPIO_MEM: + case UPIO_MEM16: case UPIO_MEM32: case UPIO_MEM32BE: case UPIO_AU: diff --git a/include/linux/serial_core.h b/include/linux/serial_core.h index 297d4fa..35aa87b 100644 --- a/include/linux/serial_core.h +++ b/include/linux/serial_core.h @@ -150,6 +150,7 @@ struct uart_port { #define UPIO_AU (SERIAL_IO_AU) /* Au1x00 and RT288x type IO */ #define UPIO_TSI (SERIAL_IO_TSI) /* Tsi108/109 type IO */ #define UPIO_MEM32BE (SERIAL_IO_MEM32BE) /* 32b big endian */ +#define UPIO_MEM16 (SERIAL_IO_MEM16) /* 16b little endian */ unsigned int read_status_mask; /* driver specific */ unsigned int ignore_status_mask; /* driver specific */ diff --git a/include/uapi/linux/serial.h b/include/uapi/linux/serial.h index 25331f9..5d59c3e 100644 --- a/include/uapi/linux/serial.h +++ b/include/uapi/linux/serial.h @@ -69,6 +69,7 @@ struct serial_struct { #define SERIAL_IO_AU 4 #define SERIAL_IO_TSI 5 #define SERIAL_IO_MEM32BE 6 +#define SERIAL_IO_MEM16 7 #define UART_CLEAR_FIFO 0x01 #define UART_USE_FIFO 0x02 -- 2.7.4