On Fri, Oct 26, 2012 at 05:33:16PM +0530, Vineet.Gupta1@xxxxxxxxxxxx wrote:
> From: Vineet Gupta <vgupta@xxxxxxxxxxxx>
>
> Driver for non-standard on-chip UART, instantiated in the ARC (Synopsys)
> FPGA Boards such as ARCAngel4/ML50x
>
> Signed-off-by: Vineet Gupta <vgupta@xxxxxxxxxxxx>
> ---
> drivers/tty/serial/Kconfig | 23 ++
> drivers/tty/serial/Makefile | 1 +
> drivers/tty/serial/arc_uart.c | 754 ++++++++++++++++++++++++++++++++++++++
> include/uapi/linux/serial_core.h | 2 +
> 4 files changed, 780 insertions(+), 0 deletions(-)
> create mode 100644 drivers/tty/serial/arc_uart.c
>
> diff --git a/drivers/tty/serial/Kconfig b/drivers/tty/serial/Kconfig
> index 2a53be5..b176801 100644
> --- a/drivers/tty/serial/Kconfig
> +++ b/drivers/tty/serial/Kconfig
> @@ -1423,4 +1423,27 @@ config SERIAL_EFM32_UART_CONSOLE
> depends on SERIAL_EFM32_UART=y
> select SERIAL_CORE_CONSOLE
>
> +config SERIAL_ARC
> + tristate "ARC UART driver support"
> + select SERIAL_CORE
> + help
> + Driver for on-chip UART for ARC(Synopsys) for the legacy
> + FPGA Boards (ML50x/ARCAngel4)
> +
> +config SERIAL_ARC_CONSOLE
> + bool "Console on ARC UART"
> + depends on SERIAL_ARC=y
> + select SERIAL_CORE_CONSOLE
> + help
> + Enable system Console on ARC UART
> +
> +config SERIAL_ARC_NR_PORTS
> + int "Number of ARC UART ports"
> + depends on SERIAL_ARC
> + range 1 3
> + default "1"
> + help
> + Set this to the number of serial ports you want the driver
> + to support.
> +
> endmenu
> diff --git a/drivers/tty/serial/Makefile b/drivers/tty/serial/Makefile
> index 4f694da..df1b998 100644
> --- a/drivers/tty/serial/Makefile
> +++ b/drivers/tty/serial/Makefile
> @@ -82,3 +82,4 @@ obj-$(CONFIG_SERIAL_XILINX_PS_UART) += xilinx_uartps.o
> obj-$(CONFIG_SERIAL_SIRFSOC) += sirfsoc_uart.o
> obj-$(CONFIG_SERIAL_AR933X) += ar933x_uart.o
> obj-$(CONFIG_SERIAL_EFM32_UART) += efm32-uart.o
> +obj-$(CONFIG_SERIAL_ARC) += arc_uart.o
> diff --git a/drivers/tty/serial/arc_uart.c b/drivers/tty/serial/arc_uart.c
> new file mode 100644
> index 0000000..c12efae
> --- /dev/null
> +++ b/drivers/tty/serial/arc_uart.c
> @@ -0,0 +1,754 @@
> +/*
> + * ARC On-Chip(fpga) UART Driver
> + *
> + * Copyright (C) 2010-2012 Synopsys, Inc. (www.synopsys.com)
> + *
> + * This program is free software; you can redistribute it and/or modify
> + * it under the terms of the GNU General Public License version 2 as
> + * published by the Free Software Foundation.
> + *
> + * vineetg: July 10th 2012
> + * -Decoupled the driver from arch/arc
> + * +Using platform_get_resource() for irq/membase (thx to bfin_uart.c)
> + * +Using early_platform_xxx() for early console (thx to mach-shmobile/xxx)
> + *
> + * Vineetg: Aug 21st 2010
> + * -Is uart_tx_stopped() not done in tty write path as it has already been
> + * taken care of, in serial core
> + *
> + * Vineetg: Aug 18th 2010
> + * -New Serial Core based ARC UART driver
> + * -Derived largely from blackfin driver albiet with some major tweaks
> + *
> + * TODO:
> + * -check if sysreq works
> + */
> +
> +#if defined(CONFIG_SERIAL_ARC_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/tty.h>
> +#include <linux/tty_flip.h>
> +#include <linux/serial_core.h>
> +#include <linux/io.h>
> +
> +/*************************************
> + * ARC UART Hardware Specs
> + ************************************/
> +#define ARC_UART_TX_FIFO_SIZE 1
> +
> +/*
> + * UART Register set (this is not a Standards Compliant IP)
> + * Also each reg is Word aligned, but only 8 bits wide
> + */
> +#define R_ID0 0
> +#define R_ID1 4
> +#define R_ID2 8
> +#define R_ID3 12
> +#define R_DATA 16
> +#define R_STS 20
> +#define R_BAUDL 24
> +#define R_BAUDH 28
> +
> +/* Bits for UART Status Reg (R/W) */
> +#define RXIENB 0x04 /* Receive Interrupt Enable */
> +#define TXIENB 0x40 /* Transmit Interrupt Enable */
> +
> +#define RXEMPTY 0x20 /* Receive FIFO Empty: No char receivede */
> +#define TXEMPTY 0x80 /* Transmit FIFO Empty, thus char can be written into */
> +
> +#define RXFULL 0x08 /* Receive FIFO full */
> +#define RXFULL1 0x10 /* Receive FIFO has space for 1 char (tot space=4) */
> +
> +#define RXFERR 0x01 /* Frame Error: Stop Bit not detected */
> +#define RXOERR 0x02 /* OverFlow Err: Char recv but RXFULL still set */
> +
> +/* Uart bit fiddling helpers: lowest level */
> +#define RBASE(uart, reg) (uart->port.membase + reg)
> +#define UART_REG_SET(u, r, v) writeb((v), RBASE(u, r))
> +#define UART_REG_GET(u, r) readb(RBASE(u, r))
> +
> +#define UART_REG_OR(u, r, v) UART_REG_SET(u, r, UART_REG_GET(u, r) | (v))
> +#define UART_REG_CLR(u, r, v) UART_REG_SET(u, r, UART_REG_GET(u, r) & ~(v))
> +
> +/* Uart bit fiddling helpers: API level */
> +#define UART_SET_DATA(uart, val) UART_REG_SET(uart, R_DATA, val)
> +#define UART_GET_DATA(uart) UART_REG_GET(uart, R_DATA)
> +
> +#define UART_SET_BAUDH(uart, val) UART_REG_SET(uart, R_BAUDH, val)
> +#define UART_SET_BAUDL(uart, val) UART_REG_SET(uart, R_BAUDL, val)
> +
> +#define UART_CLR_STATUS(uart, val) UART_REG_CLR(uart, R_STS, val)
> +#define UART_GET_STATUS(uart) UART_REG_GET(uart, R_STS)
> +
> +#define UART_ALL_IRQ_DISABLE(uart) UART_REG_CLR(uart, R_STS, RXIENB|TXIENB)
> +#define UART_RX_IRQ_DISABLE(uart) UART_REG_CLR(uart, R_STS, RXIENB)
> +#define UART_TX_IRQ_DISABLE(uart) UART_REG_CLR(uart, R_STS, TXIENB)
> +
> +#define UART_ALL_IRQ_ENABLE(uart) UART_REG_OR(uart, R_STS, RXIENB|TXIENB)
> +#define UART_RX_IRQ_ENABLE(uart) UART_REG_OR(uart, R_STS, RXIENB)
> +#define UART_TX_IRQ_ENABLE(uart) UART_REG_OR(uart, R_STS, TXIENB)
> +
> +#define ARC_SERIAL_DEV_NAME "ttyARC"
> +
> +struct arc_uart_port {
> + struct uart_port port;
> + unsigned long baud;
> + int is_emulated; /* H/w vs. Instruction Set Simulator */
> +};
> +
> +static struct arc_uart_port arc_uart_ports[CONFIG_SERIAL_ARC_NR_PORTS];
> +
> +#ifdef CONFIG_SERIAL_ARC_CONSOLE
> +static struct console arc_console;
> +#endif
> +
> +#define DRIVER_NAME "arc-uart"
> +
> +static struct uart_driver arc_uart_driver = {
> + .owner = THIS_MODULE,
> + .driver_name = DRIVER_NAME,
> + .dev_name = ARC_SERIAL_DEV_NAME,
> + .major = 0,
> + .minor = 0,
> + .nr = CONFIG_SERIAL_ARC_NR_PORTS,
> +#ifdef CONFIG_SERIAL_ARC_CONSOLE
> + .cons = &arc_console,
> +#else
> + .cons = NULL,
else branch isn't necessary. The structure is declared static and
everything is initialized to zero unless overwritten by code.
> +#endif
> +};
> +
> +static void arc_serial_stop_rx(struct uart_port *port)
> +{
> + struct arc_uart_port *uart = (struct arc_uart_port *)port;
I would suggest using container_of() here. It's very unlikely to happen,
but if another field is added before struct uart_port member in your
structure, this will break.
> + UART_RX_IRQ_DISABLE(uart);
> +}
> +
> +static void arc_serial_stop_tx(struct uart_port *port)
> +{
> + struct arc_uart_port *uart = (struct arc_uart_port *)port;
> +
> + while (!(UART_GET_STATUS(uart) & TXEMPTY))
> + cpu_relax();
> +
> + UART_TX_IRQ_DISABLE(uart);
> +}
> +
> +/*
> + * Return TIOCSER_TEMT when transmitter is not busy.
> + */
> +static unsigned int arc_serial_tx_empty(struct uart_port *port)
> +{
> + struct arc_uart_port *uart = (struct arc_uart_port *)port;
> + unsigned int stat;
> +
> + stat = UART_GET_STATUS(uart);
> + if (stat & TXEMPTY)
> + return TIOCSER_TEMT;
> + else
> + return 0;
else is unnecessary you can convert this into:
if (stat & TXEMPTY)
return TIOCSER_TEMT;
return 0;
> +}
> +
> +/*
> + * Driver internal routine, used by both tty(serial core) as well as tx-isr
> + * -Called under spinlock in either cases
> + * -also tty->stopped / tty->hw_stopped has already been checked
> + * = by uart_start( ) before calling us
> + * = tx_ist checks that too before calling
> + */
> +static void arc_serial_tx_chars(struct arc_uart_port *uart)
> +{
> + struct circ_buf *xmit = &uart->port.state->xmit;
> + int sent = 0;
> + unsigned char ch;
> +
> + if (unlikely(uart->port.x_char)) {
> + UART_SET_DATA(uart, uart->port.x_char);
> + uart->port.icount.tx++;
> + uart->port.x_char = 0;
> + sent = 1;
> + } else if (xmit->tail != xmit->head) { /* TODO: uart_circ_empty */
> + ch = xmit->buf[xmit->tail];
> + xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
> + uart->port.icount.tx++;
> + while (!(UART_GET_STATUS(uart) & TXEMPTY))
> + cpu_relax();
> + UART_SET_DATA(uart, ch);
> + sent = 1;
> + }
> +
> + /*
> + * If num chars in xmit buffer are too few, ask tty layer for more.
> + * By Hard ISR to schedule processing in software interrupt part
> + */
> + if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
> + uart_write_wakeup(&uart->port);
> +
> + if (sent)
> + UART_TX_IRQ_ENABLE(uart);
> +}
> +
> +/*
> + * port is locked and interrupts are disabled
> + * uart_start( ) calls us under the port spinlock irqsave
> + */
> +static void arc_serial_start_tx(struct uart_port *port)
> +{
> + struct arc_uart_port *uart = (struct arc_uart_port *)port;
> +
> + arc_serial_tx_chars(uart);
> +}
> +
> +static void arc_serial_rx_chars(struct arc_uart_port *uart)
> +{
> + struct tty_struct *tty = tty_port_tty_get(&uart->port.state->port);
> + unsigned int status, ch, flg = 0;
> +
> + if (!tty)
> + return;
can this really happen ? why would you receive characters while tty is
NULL ?
> + /*
> + * UART has 4 deep RX-FIFO. Driver's recongnition of this fact
> + * is very subtle. Here's how ...
> + * Upon getting a RX-Intr, such that RX-EMPTY=0, meaning data available,
> + * driver reads the DATA Reg and keeps doing that in a loop, until
> + * RX-EMPTY=1. Multiple chars being avail, with a single Interrupt,
> + * before RX-EMPTY=0, implies some sort of buffering going on in the
> + * controller, which is indeed the Rx-FIFO.
> + */
> + while (!((status = UART_GET_STATUS(uart)) & RXEMPTY)) {
> +
> + ch = UART_GET_DATA(uart);
> + uart->port.icount.rx++;
> +
> + if (unlikely(status & (RXOERR | RXFERR))) {
> + if (status & RXOERR) {
> + uart->port.icount.overrun++;
> + flg = TTY_OVERRUN;
> + UART_CLR_STATUS(uart, RXOERR);
> + }
> +
> + if (status & RXFERR) {
> + uart->port.icount.frame++;
> + flg = TTY_FRAME;
> + UART_CLR_STATUS(uart, RXFERR);
> + }
> + } else
> + flg = TTY_NORMAL;
> +
> + if (unlikely(uart_handle_sysrq_char(&uart->port, ch)))
> + goto done;
> +
> + uart_insert_char(&uart->port, status, RXOERR, ch, flg);
> +
> +done:
> + tty_flip_buffer_push(tty);
> + }
> +
> + tty_kref_put(tty);
> +}
> +
> +/*
> + * A note on the Interrupt handling state machine of this driver
> + *
> + * kernel printk writes funnel thru the console driver framework and in order
> + * to keep things simple as well as efficient, it writes to UART in polled
> + * mode, in one shot, and exits.
> + *
> + * OTOH, Userland output (via tty layer), uses interrupt based writes as there
> + * can be undeterministic delay between char writes.
> + *
> + * Thus Rx-interrupts are always enabled, while tx-interrupts are by default
> + * disabled.
> + *
> + * When tty has some data to send out, serial core calls driver's start_tx
> + * which
> + * -checks-if-tty-buffer-has-char-to-send
> + * -writes-data-to-uart
> + * -enable-tx-intr
> + *
> + * Once data bits are pushed out, controller raises the Tx-room-avail-Interrupt.
> + * The first thing Tx ISR does is disable further Tx interrupts (as this could
> + * be the last char to send, before settling down into the quiet polled mode).
> + * It then calls the exact routine used by tty layer write to send out any
> + * more char in tty buffer. In case of sending, it re-enables Tx-intr. In case
> + * of no data, it remains disabled.
> + * This is how the transmit state machine is dynamically switched on/off
> + */
> +
> +static irqreturn_t arc_serial_isr(int irq, void *dev_id)
> +{
> + struct arc_uart_port *uart = dev_id;
> + unsigned int status;
> +
> + status = UART_GET_STATUS(uart);
> +
> + /*
> + * Single IRQ for both Rx (data available) Tx (room available) Interrupt
> + * notifications from the UART Controller.
> + * To demultiplex between the two, we check the relevant bits
> + */
> + if ((status & RXIENB) && !(status & RXEMPTY)) {
> +
> + /* already in ISR, no need of xx_irqsave */
> + spin_lock(&uart->port.lock);
> + arc_serial_rx_chars(uart);
> + spin_unlock(&uart->port.lock);
> + }
> +
> + if ((status & TXIENB) && (status & TXEMPTY)) {
> +
> + /* Unconditionally disable further Tx-Interrupts.
> + * will be enabled by tx_chars() if needed.
> + */
> + UART_TX_IRQ_DISABLE(uart);
> +
> + spin_lock(&uart->port.lock);
> +
> + if (!uart_tx_stopped(&uart->port))
> + arc_serial_tx_chars(uart);
> +
> + spin_unlock(&uart->port.lock);
> + }
> +
> + return IRQ_HANDLED;
> +}
> +
> +static unsigned int arc_serial_get_mctrl(struct uart_port *port)
> +{
> + /*
> + * Pretend we have a Modem status reg and following bits are
> + * always set, to satify the serial core state machine
> + * (DSR) Data Set Ready
> + * (CTS) Clear To Send
> + * (CAR) Carrier Detect
> + */
> + return TIOCM_CTS | TIOCM_DSR | TIOCM_CAR;
> +}
> +
> +static void arc_serial_set_mctrl(struct uart_port *port, unsigned int mctrl)
> +{
> + /* MCR not present */
> +}
> +
> +/* Enable Modem Status Interrupts */
> +
> +static void arc_serial_enable_ms(struct uart_port *port)
> +{
> + /* MSR not present */
> +}
> +
> +static void arc_serial_break_ctl(struct uart_port *port, int break_state)
> +{
> + /* ARC UART doesn't support sending Break signal */
> +}
> +
> +static int arc_serial_startup(struct uart_port *port)
> +{
> + struct arc_uart_port *uart = (struct arc_uart_port *)port;
> +
> + /* Before we hook up the ISR, Disable all UART Interrupts */
> + UART_ALL_IRQ_DISABLE(uart);
> +
> + if (request_irq(uart->port.irq, arc_serial_isr, 0, "arc uart rx-tx",
> + uart)) {
> + pr_warn("Unable to attach ARC UART interrupt\n");
> + return -EBUSY;
> + }
> +
> + UART_RX_IRQ_ENABLE(uart); /* Only Rx IRQ enabled to begin with */
> +
> + return 0;
> +}
> +
> +/* This is not really needed */
> +static void arc_serial_shutdown(struct uart_port *port)
> +{
> + struct arc_uart_port *uart = (struct arc_uart_port *)port;
> + free_irq(uart->port.irq, uart);
> +}
> +
> +static void
> +arc_serial_set_termios(struct uart_port *port, struct ktermios *new,
> + struct ktermios *old)
> +{
> + struct arc_uart_port *uart = (struct arc_uart_port *)port;
> + unsigned int baud, uartl, uarth, hw_val;
> + unsigned long flags;
> +
> + /*
> + * Use the generic handler so that any specially encoded baud rates
> + * such as SPD_xx flags or "%B0" can be handled
> + * Max Baud I suppose will not be more than current 115K * 4
> + * Formula for ARC UART is: hw-val = ((CLK/(BAUD*4)) -1)
> + * spread over two 8-bit registers
> + */
> + baud = uart_get_baud_rate(port, new, old, 0, 460800);
> +
> + hw_val = port->uartclk / (uart->baud * 4) - 1;
> + uartl = hw_val & 0xFF;
> + uarth = (hw_val >> 8) & 0xFF;
> +
> + /*
> + * UART ISS(Instruction Set simulator) emulation has a subtle bug:
> + * A existing value of Baudh = 0 is used as a indication to startup
> + * it's internal state machine.
> + * Thus if baudh is set to 0, 2 times, it chokes.
> + * This happens with BAUD=115200 and the formaula above
> + * Until that is fixed, when running on ISS, we will set baudh to !0
> + */
> + if (uart->is_emulated)
> + uarth = 1;
> +
> + spin_lock_irqsave(&port->lock, flags);
> +
> + UART_ALL_IRQ_DISABLE(uart);
> +
> + UART_SET_BAUDL(uart, uartl);
> + UART_SET_BAUDH(uart, uarth);
> +
> + UART_RX_IRQ_ENABLE(uart);
> +
> + /*
> + * UART doesn't support Parity/Hardware Flow Control;
> + * Only supports 8N1 character size
> + */
> + new->c_cflag &= ~(CMSPAR|CRTSCTS|CSIZE);
> + new->c_cflag |= CS8;
> +
> + if (old)
> + tty_termios_copy_hw(new, old);
> +
> + /* Don't rewrite B0 */
> + if (tty_termios_baud_rate(new))
> + tty_termios_encode_baud_rate(new, baud, baud);
> +
> + uart_update_timeout(port, new->c_cflag, baud);
> +
> + spin_unlock_irqrestore(&port->lock, flags);
> +}
> +
> +static const char *arc_serial_type(struct uart_port *port)
> +{
> + struct arc_uart_port *uart = (struct arc_uart_port *)port;
> +
> + return uart->port.type == PORT_ARC ? DRIVER_NAME : NULL;
> +}
> +
> +/*
> + * Release the memory region(s) being used by 'port'.
> + */
> +static void arc_serial_release_port(struct uart_port *port)
> +{
> +}
> +
> +/*
> + * Request the memory region(s) being used by 'port'.
> + */
> +static int arc_serial_request_port(struct uart_port *port)
> +{
> + return 0;
> +}
> +
> +/*
> + * Verify the new serial_struct (for TIOCSSERIAL).
> + */
> +static int
> +arc_serial_verify_port(struct uart_port *port, struct serial_struct *ser)
> +{
> + return 0;
> +}
why all these empty functions with wrong comments above them ??
> +/*
> + * Configure/autoconfigure the port.
> + */
> +static void arc_serial_config_port(struct uart_port *port, int flags)
> +{
> + struct arc_uart_port *uart = (struct arc_uart_port *)port;
> +
> + if (flags & UART_CONFIG_TYPE &&
> + arc_serial_request_port(&uart->port) == 0)
> + uart->port.type = PORT_ARC;
> +}
> +
> +#if defined(CONFIG_CONSOLE_POLL) || defined(CONFIG_SERIAL_ARC_CONSOLE)
> +
> +static void arc_serial_poll_putchar(struct uart_port *port, unsigned char chr)
> +{
> + struct arc_uart_port *uart = (struct arc_uart_port *)port;
> +
> + while (!(UART_GET_STATUS(uart) & TXEMPTY))
> + cpu_relax();
> +
> + UART_SET_DATA(uart, chr);
> +}
> +#endif
> +
> +#ifdef CONFIG_CONSOLE_POLL
> +static int arc_serial_poll_getchar(struct uart_port *port)
> +{
> + struct arc_uart_port *uart = (struct arc_uart_port *)port;
> + unsigned char chr;
> +
> + while (!(UART_GET_STATUS(uart) & RXEMPTY))
> + cpu_relax();
> +
> + chr = UART_GET_DATA(uart);
> + return chr;
> +}
> +#endif
> +
> +static struct uart_ops arc_serial_pops = {
> + .tx_empty = arc_serial_tx_empty,
> + .set_mctrl = arc_serial_set_mctrl,
> + .get_mctrl = arc_serial_get_mctrl,
> + .stop_tx = arc_serial_stop_tx,
> + .start_tx = arc_serial_start_tx,
> + .stop_rx = arc_serial_stop_rx,
> + .enable_ms = arc_serial_enable_ms,
> + .break_ctl = arc_serial_break_ctl,
> + .startup = arc_serial_startup,
> + .shutdown = arc_serial_shutdown,
> + .set_termios = arc_serial_set_termios,
> + .type = arc_serial_type,
> + .release_port = arc_serial_release_port,
> + .request_port = arc_serial_request_port,
> + .config_port = arc_serial_config_port,
> + .verify_port = arc_serial_verify_port,
> +#ifdef CONFIG_CONSOLE_POLL
> + .poll_put_char = arc_serial_poll_putchar,
> + .poll_get_char = arc_serial_poll_getchar,
> +#endif
> +};
> +
> +static int __devinit
> +arc_uart_init_one(struct platform_device *pdev, struct arc_uart_port *uart)
> +{
> + struct resource *res, *res2;
> + unsigned long *plat_data;
> +
> + if (pdev->id < 0 || pdev->id >= CONFIG_SERIAL_ARC_NR_PORTS) {
> + dev_err(&pdev->dev, "Wrong uart platform device id.\n");
> + return -ENOENT;
> + }
> +
> + plat_data = ((unsigned long *)(pdev->dev.platform_data));
> + uart->baud = plat_data[0];
> +
> + res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> + if (!res)
> + return -ENODEV;
> +
> + res2 = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
> + if (!res2)
> + return -ENODEV;
> +
> + uart->port.mapbase = res->start;
> + uart->port.membase = ioremap_nocache(res->start, resource_size(res));
> + if (!uart->port.membase)
> + /* No point of pr_err since UART itself is hosed here */
> + return -ENXIO;
> +
> + uart->port.irq = res2->start;
> + uart->port.dev = &pdev->dev;
> + uart->port.iotype = UPIO_MEM;
> + uart->port.flags = UPF_BOOT_AUTOCONF;
> + uart->port.line = pdev->id;
> + uart->port.ops = &arc_serial_pops;
> +
> + uart->port.uartclk = plat_data[1];
> + uart->port.fifosize = ARC_UART_TX_FIFO_SIZE;
> +
> + /*
> + * uart_insert_char( ) uses it in decideding whether to ignore a
> + * char or not. Explicitly setting it here, removes the subtelty
> + */
> + uart->port.ignore_status_mask = 0;
> +
> + /* Real Hardware vs. emulated to work around a bug */
> + uart->is_emulated = !!plat_data[2];
> +
> + return 0;
> +}
> +
> +#ifdef CONFIG_SERIAL_ARC_CONSOLE
> +
> +static int __devinit arc_serial_console_setup(struct console *co, char *options)
> +{
> + struct uart_port *port;
> + int baud = 115200;
> + int bits = 8;
> + int parity = 'n';
> + int flow = 'n';
> +
> + if (co->index < 0 || co->index >= CONFIG_SERIAL_ARC_NR_PORTS)
> + return -ENODEV;
> +
> + /*
> + * The uart port backing the console (e.g. ttyARC1) might not have been
> + * init yet. If so, defer the console setup to after the port.
> + */
> + port = &arc_uart_ports[co->index].port;
> + if (!port->membase)
> + return -ENODEV;
> +
> + if (options)
> + uart_parse_options(options, &baud, &parity, &bits, &flow);
> +
> + /*
> + * Serial core will call port->ops->set_termios( )
> + * which will set the baud reg
> + */
> + return uart_set_options(port, co, baud, parity, bits, flow);
> +}
> +
> +static void arc_serial_console_putchar(struct uart_port *port, int ch)
> +{
> + arc_serial_poll_putchar(port, (unsigned char)ch);
> +}
> +
> +/*
> + * Interrupts are disabled on entering
> + */
> +static void arc_serial_console_write(struct console *co, const char *s,
> + unsigned int count)
> +{
> + struct uart_port *port = &arc_uart_ports[co->index].port;
> + unsigned long flags;
> +
> + spin_lock_irqsave(&port->lock, flags);
> + uart_console_write(port, s, count, arc_serial_console_putchar);
> + spin_unlock_irqrestore(&port->lock, flags);
> +}
> +
> +static struct console arc_console = {
> + .name = ARC_SERIAL_DEV_NAME,
> + .write = arc_serial_console_write,
> + .device = uart_console_device,
> + .setup = arc_serial_console_setup,
> + .flags = CON_PRINTBUFFER,
> + .index = -1,
> + .data = &arc_uart_driver
> +};
> +
> +static __init void early_serial_write(struct console *con, const char *s,
> + unsigned int n)
> +{
> + struct uart_port *port = &arc_uart_ports[con->index].port;
> + unsigned int i;
> +
> + for (i = 0; i < n; i++, s++) {
> + if (*s == '\n')
> + arc_serial_poll_putchar(port, '\r');
> + arc_serial_poll_putchar(port, *s);
> + }
> +}
> +
> +static struct __initdata console arc_early_serial_console = {
> + .name = "early_ARCuart",
> + .write = early_serial_write,
> + .flags = CON_PRINTBUFFER | CON_BOOT,
> + .index = -1
> +};
> +
> +static int __devinit arc_serial_probe_earlyprintk(struct platform_device *pdev)
> +{
> + arc_early_serial_console.index = pdev->id;
> +
> + arc_uart_init_one(pdev, &arc_uart_ports[pdev->id]);
> +
> + arc_serial_console_setup(&arc_early_serial_console, NULL);
> +
> + register_console(&arc_early_serial_console);
> + return 0;
> +}
> +#else
> +static int __devinit arc_serial_probe_earlyprintk(struct platform_device *pdev)
> +{
> + return -ENODEV;
> +}
> +#endif /* CONFIG_SERIAL_ARC_CONSOLE */
> +
> +static int __devinit arc_serial_probe(struct platform_device *pdev)
> +{
> + struct arc_uart_port *uart;
> + int rc;
> +
> + if (is_early_platform_device(pdev))
> + return arc_serial_probe_earlyprintk(pdev);
> +
> + uart = &arc_uart_ports[pdev->id];
> + rc = arc_uart_init_one(pdev, uart);
> + if (rc)
> + return rc;
> +
> + return uart_add_one_port(&arc_uart_driver, &uart->port);
> +}
> +
> +static int __devexit arc_serial_remove(struct platform_device *pdev)
> +{
> + /* This will never be called */
> + return 0;
> +}
> +
> +static struct platform_driver arc_platform_driver = {
> + .probe = arc_serial_probe,
> + .remove = __devexit_p(arc_serial_remove),
> + .driver = {
> + .name = DRIVER_NAME,
> + .owner = THIS_MODULE,
> + },
> +};
> +
> +#ifdef CONFIG_SERIAL_ARC_CONSOLE
> +/*
> + * Register an early platform driver of "earlyprintk" class.
> + * ARCH platform code installs the driver and probes the early devices
> + * The installation could rely on user specifying earlyprintk=xyx in cmd line
> + * or it could be done independently, for all "earlyprintk" class drivers.
> + * [see arch/arc/plat-arcfpga/platform.c]
> + */
> +early_platform_init("earlyprintk", &arc_platform_driver);
> +
> +#endif /* CONFIG_SERIAL_ARC_CONSOLE */
> +
> +static int __init arc_serial_init(void)
> +{
> + int ret;
> +
> + pr_info("Serial: ARC serial driver: platform register\n");
please remove this line, it's just useless IMHO.
--
balbi
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