* [PATCH] serial/arc-uart: Add new driver
2012-10-25 6:30 [PATCH v4] serial/arc-uart: Add New Driver Vineet.Gupta1
@ 2012-10-25 6:30 ` Vineet.Gupta1
2012-10-25 18:36 ` Greg KH
2012-10-25 18:36 ` [PATCH v4] serial/arc-uart: Add New Driver Greg KH
1 sibling, 1 reply; 6+ messages in thread
From: Vineet.Gupta1 @ 2012-10-25 6:30 UTC (permalink / raw)
To: alan, gregkh; +Cc: arc-linux-dev, linux-serial, linux-kernel, Vineet Gupta
From: Vineet Gupta <vgupta@synopsys.com>
Driver for non-standard on-chip UART, instantiated in the ARC (Synopsys)
FPGA Boards such as ARCAngel4/ML50x
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
---
drivers/tty/serial/Kconfig | 25 ++
drivers/tty/serial/Makefile | 1 +
drivers/tty/serial/arc_uart.c | 747 ++++++++++++++++++++++++++++++++++++++
include/uapi/linux/serial_core.h | 2 +
4 files changed, 775 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..efee7fe 100644
--- a/drivers/tty/serial/Kconfig
+++ b/drivers/tty/serial/Kconfig
@@ -1423,4 +1423,29 @@ config SERIAL_EFM32_UART_CONSOLE
depends on SERIAL_EFM32_UART=y
select SERIAL_CORE_CONSOLE
+config SERIAL_ARC
+ bool "ARC UART driver support"
+ select SERIAL_CORE
+ default y
+ help
+ Driver for on-chip UART for ARC(Synopsys) for the legacy
+ FPGA Boards (ML50x/ARCAngel4)
+
+config SERIAL_ARC_CONSOLE
+ bool
+ select SERIAL_CORE_CONSOLE
+ depends on SERIAL_ARC=y
+ default y
+ help
+ Enable system Console on ARC UART
+
+config SERIAL_ARC_NR_PORTS
+ int 'Number of ports'
+ range 1 3
+ default 1
+ depends on SERIAL_ARC
+ 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..9215bf4
--- /dev/null
+++ b/drivers/tty/serial/arc_uart.c
@@ -0,0 +1,747 @@
+/*
+ * 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 1
+#define R_ID2 2
+#define R_ID3 3
+#define R_DATA 4
+#define R_STS 5
+#define R_BAUDL 6
+#define R_BAUDH 7
+
+/* 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) ((unsigned int *)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,
+#endif
+};
+
+static void arc_serial_stop_rx(struct uart_port *port)
+{
+ struct arc_uart_port *uart = (struct arc_uart_port *)port;
+
+ 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;
+}
+
+/*
+ * 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;
+
+ /*
+ * 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;
+}
+
+/*
+ * 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;
+}
+
+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);
+}
+
+#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;
+}
+#endif
+
+
+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");
+
+ ret = uart_register_driver(&arc_uart_driver);
+ if (ret)
+ return ret;
+
+ ret = platform_driver_register(&arc_platform_driver);
+ if (ret) {
+ pr_debug("uart register failed\n");
+ uart_unregister_driver(&arc_uart_driver);
+ }
+
+ return ret;
+}
+
+static void __exit arc_serial_exit(void)
+{
+ platform_driver_unregister(&arc_platform_driver);
+ uart_unregister_driver(&arc_uart_driver);
+}
+
+module_init(arc_serial_init);
+module_exit(arc_serial_exit);
+
+MODULE_LICENSE("GPL");
+MODULE_ALIAS("plat-arcfpga/uart");
+MODULE_AUTHOR("Vineet Gupta");
+MODULE_DESCRIPTION("ARC(Synopsys) On-Chip(fpga) serial driver");
diff --git a/include/uapi/linux/serial_core.h b/include/uapi/linux/serial_core.h
index 7e1ab20..ebcc73f 100644
--- a/include/uapi/linux/serial_core.h
+++ b/include/uapi/linux/serial_core.h
@@ -215,5 +215,7 @@
/* Energy Micro efm32 SoC */
#define PORT_EFMUART 100
+/* ARC (Synopsys) on-chip UART */
+#define PORT_ARC 101
#endif /* _UAPILINUX_SERIAL_CORE_H */
--
1.7.4.1
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