blackfin: serial driver

This patch implements the driver necessary use the Analog Devices Blackfin
processor's Serial Port.
Signed-off-by: Bryan Wu <bryan.wu@analog.com>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Cc: Russell King <rmk+lkml@arm.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

drivers/serial/Kconfig

@@ -508,6 +508,100 @@ config SERIAL_SA1100_CONSOLE
 	  your boot loader (lilo or loadlin) about how to pass options to the
 	  kernel at boot time.)
 
+config SERIAL_BFIN
+	tristate "Blackfin serial port support"
+	depends on BFIN
+	select SERIAL_CORE
+	select SERIAL_BFIN_UART0 if (BF531 || BF532 || BF533 || BF561)
+	help
+	  Add support for the built-in UARTs on the Blackfin.
+
+	  To compile this driver as a module, choose M here: the
+	  module will be called bfin_5xx.
+
+config SERIAL_BFIN_CONSOLE
+	bool "Console on Blackfin serial port"
+	depends on SERIAL_BFIN
+	select SERIAL_CORE_CONSOLE
+
+choice
+	prompt "UART Mode"
+	depends on SERIAL_BFIN
+	default SERIAL_BFIN_DMA
+	help
+	  This driver supports the built-in serial ports of the Blackfin family
+	  of CPUs
+
+config SERIAL_BFIN_DMA
+	bool "DMA mode"
+	depends on DMA_UNCACHED_1M
+	help
+	  This driver works under DMA mode. If this option is selected, the
+	  blackfin simple dma driver is also enabled.
+
+config SERIAL_BFIN_PIO
+	bool "PIO mode"
+	help
+	  This driver works under PIO mode.
+
+endchoice
+
+config SERIAL_BFIN_UART0
+	bool "Enable UART0"
+	depends on SERIAL_BFIN
+	help
+	  Enable UART0
+
+config BFIN_UART0_CTSRTS
+	bool "Enable UART0 hardware flow control"
+	depends on SERIAL_BFIN_UART0
+	help
+	  Enable hardware flow control in the driver. Using GPIO emulate the CTS/RTS
+	  signal.
+
+config UART0_CTS_PIN
+	int "UART0 CTS pin"
+	depends on BFIN_UART0_CTSRTS
+	default 23
+	help
+	  The default pin is GPIO_GP7.
+	  Refer to ./include/asm-blackfin/gpio.h to see the GPIO map.
+
+config UART0_RTS_PIN
+	int "UART0 RTS pin"
+	depends on BFIN_UART0_CTSRTS
+	default 22
+	help
+	  The default pin is GPIO_GP6.
+	  Refer to ./include/asm-blackfin/gpio.h to see the GPIO map.
+
+config SERIAL_BFIN_UART1
+	bool "Enable UART1"
+	depends on SERIAL_BFIN && (BF534 || BF536 || BF537)
+	help
+	  Enable UART1
+
+config BFIN_UART1_CTSRTS
+	bool "Enable UART1 hardware flow control"
+	depends on SERIAL_BFIN_UART1
+	help
+	  Enable hardware flow control in the driver. Using GPIO emulate the CTS/RTS
+	  signal.
+
+config UART1_CTS_PIN
+	int "UART1 CTS pin"
+	depends on BFIN_UART1_CTSRTS
+	default -1
+	help
+	  Refer to ./include/asm-blackfin/gpio.h to see the GPIO map.
+
+config UART1_RTS_PIN
+	int "UART1 RTS pin"
+	depends on BFIN_UART1_CTSRTS
+	default -1
+	help
+	  Refer to ./include/asm-blackfin/gpio.h to see the GPIO map.
+
 config SERIAL_IMX
 	bool "IMX serial port support"
 	depends on ARM && ARCH_IMX

drivers/serial/Makefile

@@ -27,6 +27,7 @@ obj-$(CONFIG_SERIAL_CLPS711X) += clps711x.o
 obj-$(CONFIG_SERIAL_PXA) += pxa.o
 obj-$(CONFIG_SERIAL_PNX8XXX) += pnx8xxx_uart.o
 obj-$(CONFIG_SERIAL_SA1100) += sa1100.o
+obj-$(CONFIG_SERIAL_BFIN) += bfin_5xx.o
 obj-$(CONFIG_SERIAL_S3C2410) += s3c2410.o
 obj-$(CONFIG_SERIAL_SUNCORE) += suncore.o
 obj-$(CONFIG_SERIAL_SUNHV) += sunhv.o

drivers/serial/bfin_5xx.c

+/*
+ * File:         drivers/serial/bfin_5xx.c
+ * Based on:     Based on drivers/serial/sa1100.c
+ * Author:       Aubrey Li <aubrey.li@analog.com>
+ *
+ * Created:
+ * Description:  Driver for blackfin 5xx serial ports
+ *
+ * Rev:          $Id: bfin_5xx.c,v 1.19 2006/09/24 02:33:53 aubrey Exp $
+ *
+ * Modified:
+ *               Copyright 2006 Analog Devices Inc.
+ *
+ * Bugs:         Enter bugs at http://blackfin.uclinux.org/
+ *
+ * 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.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, see the file COPYING, or write
+ * to the Free Software Foundation, Inc.,
+ * 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
+ */
+
+#if defined(CONFIG_SERIAL_BFIN_CONSOLE) && defined(CONFIG_MAGIC_SYSRQ)
+#define SUPPORT_SYSRQ
+#endif
+
+#include <linux/module.h>
+#include <linux/ioport.h>
+#include <linux/init.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 <asm/gpio.h>
+#include <asm/mach/bfin_serial_5xx.h>
+
+#ifdef CONFIG_SERIAL_BFIN_DMA
+#include <linux/dma-mapping.h>
+#include <asm/io.h>
+#include <asm/irq.h>
+#include <asm/cacheflush.h>
+#endif
+
+/* UART name and device definitions */
+#define BFIN_SERIAL_NAME	"ttyBF"
+#define BFIN_SERIAL_MAJOR	204
+#define BFIN_SERIAL_MINOR	64
+
+/*
+ * Setup for console. Argument comes from the menuconfig
+ */
+#define DMA_RX_XCOUNT		512
+#define DMA_RX_YCOUNT		(PAGE_SIZE / DMA_RX_XCOUNT)
+
+#define DMA_RX_FLUSH_JIFFIES	5
+
+#ifdef CONFIG_SERIAL_BFIN_DMA
+static void bfin_serial_dma_tx_chars(struct bfin_serial_port *uart);
+#else
+static void bfin_serial_do_work(struct work_struct *work);
+static void bfin_serial_tx_chars(struct bfin_serial_port *uart);
+static void local_put_char(struct bfin_serial_port *uart, char ch);
+#endif
+
+static void bfin_serial_mctrl_check(struct bfin_serial_port *uart);
+
+/*
+ * interrupts are disabled on entry
+ */
+static void bfin_serial_stop_tx(struct uart_port *port)
+{
+	struct bfin_serial_port *uart = (struct bfin_serial_port *)port;
+
+#ifdef CONFIG_SERIAL_BFIN_DMA
+	disable_dma(uart->tx_dma_channel);
+#else
+	unsigned short ier;
+
+	ier = UART_GET_IER(uart);
+	ier &= ~ETBEI;
+	UART_PUT_IER(uart, ier);
+#endif
+}
+
+/*
+ * port is locked and interrupts are disabled
+ */
+static void bfin_serial_start_tx(struct uart_port *port)
+{
+	struct bfin_serial_port *uart = (struct bfin_serial_port *)port;
+
+#ifdef CONFIG_SERIAL_BFIN_DMA
+	bfin_serial_dma_tx_chars(uart);
+#else
+	unsigned short ier;
+	ier = UART_GET_IER(uart);
+	ier |= ETBEI;
+	UART_PUT_IER(uart, ier);
+	bfin_serial_tx_chars(uart);
+#endif
+}
+
+/*
+ * Interrupts are enabled
+ */
+static void bfin_serial_stop_rx(struct uart_port *port)
+{
+	struct bfin_serial_port *uart = (struct bfin_serial_port *)port;
+	unsigned short ier;
+
+	ier = UART_GET_IER(uart);
+	ier &= ~ERBFI;
+	UART_PUT_IER(uart, ier);
+}
+
+/*
+ * Set the modem control timer to fire immediately.
+ */
+static void bfin_serial_enable_ms(struct uart_port *port)
+{
+}
+
+#ifdef CONFIG_SERIAL_BFIN_PIO
+static void local_put_char(struct bfin_serial_port *uart, char ch)
+{
+	unsigned short status;
+	int flags = 0;
+
+	spin_lock_irqsave(&uart->port.lock, flags);
+
+	do {
+		status = UART_GET_LSR(uart);
+	} while (!(status & THRE));
+
+	UART_PUT_CHAR(uart, ch);
+	SSYNC();
+
+	spin_unlock_irqrestore(&uart->port.lock, flags);
+}
+
+static void bfin_serial_rx_chars(struct bfin_serial_port *uart)
+{
+	struct tty_struct *tty = uart->port.info?uart->port.info->tty:0;
+	unsigned int status, ch, flg;
+#ifdef BF533_FAMILY
+	static int in_break = 0;
+#endif
+
+	status = UART_GET_LSR(uart);
+ 	ch = UART_GET_CHAR(uart);
+ 	uart->port.icount.rx++;
+
+#ifdef BF533_FAMILY
+	/* The BF533 family of processors have a nice misbehavior where
+	 * they continuously generate characters for a "single" break.
+	 * We have to basically ignore this flood until the "next" valid
+	 * character comes across.  All other Blackfin families operate
+	 * properly though.
+	 */
+	if (in_break) {
+		if (ch != 0) {
+			in_break = 0;
+			ch = UART_GET_CHAR(uart);
+		}
+		return;
+	}
+#endif
+
+	if (status & BI) {
+#ifdef BF533_FAMILY
+		in_break = 1;
+#endif
+		uart->port.icount.brk++;
+		if (uart_handle_break(&uart->port))
+			goto ignore_char;
+		flg = TTY_BREAK;
+	} else if (status & PE) {
+		flg = TTY_PARITY;
+		uart->port.icount.parity++;
+	} else if (status & OE) {
+		flg = TTY_OVERRUN;
+		uart->port.icount.overrun++;
+	} else if (status & FE) {
+		flg = TTY_FRAME;
+		uart->port.icount.frame++;
+	} else
+		flg = TTY_NORMAL;
+
+	if (uart_handle_sysrq_char(&uart->port, ch))
+		goto ignore_char;
+	if (tty)
+		uart_insert_char(&uart->port, status, 2, ch, flg);
+
+ignore_char:
+	if (tty)
+		tty_flip_buffer_push(tty);
+}
+
+static void bfin_serial_tx_chars(struct bfin_serial_port *uart)
+{
+	struct circ_buf *xmit = &uart->port.info->xmit;
+
+	if (uart->port.x_char) {
+		UART_PUT_CHAR(uart, uart->port.x_char);
+		uart->port.icount.tx++;
+		uart->port.x_char = 0;
+		return;
+	}
+	/*
+	 * Check the modem control lines before
+	 * transmitting anything.
+	 */
+	bfin_serial_mctrl_check(uart);
+
+	if (uart_circ_empty(xmit) || uart_tx_stopped(&uart->port)) {
+		bfin_serial_stop_tx(&uart->port);
+		return;
+	}
+
+	local_put_char(uart, xmit->buf[xmit->tail]);
+	xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
+	uart->port.icount.tx++;
+
+	if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
+		uart_write_wakeup(&uart->port);
+
+	if (uart_circ_empty(xmit))
+		bfin_serial_stop_tx(&uart->port);
+}
+
+static irqreturn_t bfin_serial_int(int irq, void *dev_id)
+{
+	struct bfin_serial_port *uart = dev_id;
+	unsigned short status;
+
+	spin_lock(&uart->port.lock);
+	status = UART_GET_IIR(uart);
+	do {
+		if ((status & IIR_STATUS) == IIR_TX_READY)
+			bfin_serial_tx_chars(uart);
+		if ((status & IIR_STATUS) == IIR_RX_READY)
+			bfin_serial_rx_chars(uart);
+		status = UART_GET_IIR(uart);
+	} while (status & (IIR_TX_READY | IIR_RX_READY));
+	spin_unlock(&uart->port.lock);
+	return IRQ_HANDLED;
+}
+
+static void bfin_serial_do_work(struct work_struct *work)
+{
+	struct bfin_serial_port *uart = container_of(work, struct bfin_serial_port, cts_workqueue);
+
+	bfin_serial_mctrl_check(uart);
+}
+
+#endif
+
+#ifdef CONFIG_SERIAL_BFIN_DMA
+static void bfin_serial_dma_tx_chars(struct bfin_serial_port *uart)
+{
+	struct circ_buf *xmit = &uart->port.info->xmit;
+	unsigned short ier;
+	int flags = 0;
+
+	if (!uart->tx_done)
+		return;
+
+	uart->tx_done = 0;
+
+	if (uart->port.x_char) {
+		UART_PUT_CHAR(uart, uart->port.x_char);
+		uart->port.icount.tx++;
+		uart->port.x_char = 0;
+		uart->tx_done = 1;
+		return;
+	}
+	/*
+	 * Check the modem control lines before
+	 * transmitting anything.
+	 */
+	bfin_serial_mctrl_check(uart);
+
+	if (uart_circ_empty(xmit) || uart_tx_stopped(&uart->port)) {
+		bfin_serial_stop_tx(&uart->port);
+		uart->tx_done = 1;
+		return;
+	}
+
+	spin_lock_irqsave(&uart->port.lock, flags);
+	uart->tx_count = CIRC_CNT(xmit->head, xmit->tail, UART_XMIT_SIZE);
+	if (uart->tx_count > (UART_XMIT_SIZE - xmit->tail))
+		uart->tx_count = UART_XMIT_SIZE - xmit->tail;
+	blackfin_dcache_flush_range((unsigned long)(xmit->buf+xmit->tail),
+					(unsigned long)(xmit->buf+xmit->tail+uart->tx_count));
+	set_dma_config(uart->tx_dma_channel,
+		set_bfin_dma_config(DIR_READ, DMA_FLOW_STOP,
+			INTR_ON_BUF,
+			DIMENSION_LINEAR,
+			DATA_SIZE_8));
+	set_dma_start_addr(uart->tx_dma_channel, (unsigned long)(xmit->buf+xmit->tail));
+	set_dma_x_count(uart->tx_dma_channel, uart->tx_count);
+	set_dma_x_modify(uart->tx_dma_channel, 1);
+	enable_dma(uart->tx_dma_channel);
+	ier = UART_GET_IER(uart);
+	ier |= ETBEI;
+	UART_PUT_IER(uart, ier);
+	spin_unlock_irqrestore(&uart->port.lock, flags);
+}
+
+static void bfin_serial_dma_rx_chars(struct bfin_serial_port * uart)
+{
+	struct tty_struct *tty = uart->port.info->tty;
+	int i, flg, status;
+
+	status = UART_GET_LSR(uart);
+	uart->port.icount.rx += CIRC_CNT(uart->rx_dma_buf.head, uart->rx_dma_buf.tail, UART_XMIT_SIZE);;
+
+	if (status & BI) {
+		uart->port.icount.brk++;
+		if (uart_handle_break(&uart->port))
+			goto dma_ignore_char;
+		flg = TTY_BREAK;
+	} else if (status & PE) {
+		flg = TTY_PARITY;
+		uart->port.icount.parity++;
+	} else if (status & OE) {
+		flg = TTY_OVERRUN;
+		uart->port.icount.overrun++;
+	} else if (status & FE) {
+		flg = TTY_FRAME;
+		uart->port.icount.frame++;
+	} else
+		flg = TTY_NORMAL;
+
+	for (i = uart->rx_dma_buf.head; i < uart->rx_dma_buf.tail; i++) {
+		if (uart_handle_sysrq_char(&uart->port, uart->rx_dma_buf.buf[i]))
+			goto dma_ignore_char;
+		uart_insert_char(&uart->port, status, 2, uart->rx_dma_buf.buf[i], flg);
+	}
+dma_ignore_char:
+	tty_flip_buffer_push(tty);
+}
+
+void bfin_serial_rx_dma_timeout(struct bfin_serial_port *uart)
+{
+	int x_pos, pos;
+	int flags = 0;
+
+	bfin_serial_dma_tx_chars(uart);
+
+	spin_lock_irqsave(&uart->port.lock, flags);
+	x_pos = DMA_RX_XCOUNT - get_dma_curr_xcount(uart->rx_dma_channel);
+	if (x_pos == DMA_RX_XCOUNT)
+		x_pos = 0;
+
+	pos = uart->rx_dma_nrows * DMA_RX_XCOUNT + x_pos;
+
+	if (pos>uart->rx_dma_buf.tail) {
+		uart->rx_dma_buf.tail = pos;
+		bfin_serial_dma_rx_chars(uart);
+		uart->rx_dma_buf.head = uart->rx_dma_buf.tail;
+	}
+	spin_unlock_irqrestore(&uart->port.lock, flags);
+	uart->rx_dma_timer.expires = jiffies + DMA_RX_FLUSH_JIFFIES;
+	add_timer(&(uart->rx_dma_timer));
+}
+
+static irqreturn_t bfin_serial_dma_tx_int(int irq, void *dev_id)
+{
+	struct bfin_serial_port *uart = dev_id;
+	struct circ_buf *xmit = &uart->port.info->xmit;
+	unsigned short ier;
+
+	spin_lock(&uart->port.lock);
+	if (!(get_dma_curr_irqstat(uart->tx_dma_channel)&DMA_RUN)) {
+		clear_dma_irqstat(uart->tx_dma_channel);
+		disable_dma(uart->tx_dma_channel);
+		ier = UART_GET_IER(uart);
+		ier &= ~ETBEI;
+		UART_PUT_IER(uart, ier);
+		xmit->tail = (xmit->tail+uart->tx_count) &(UART_XMIT_SIZE -1);
+		uart->port.icount.tx+=uart->tx_count;
+
+		if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
+			uart_write_wakeup(&uart->port);
+
+		if (uart_circ_empty(xmit))
+			bfin_serial_stop_tx(&uart->port);
+		uart->tx_done = 1;
+	}
+
+	spin_unlock(&uart->port.lock);
+	return IRQ_HANDLED;
+}
+
+static irqreturn_t bfin_serial_dma_rx_int(int irq, void *dev_id)
+{
+	struct bfin_serial_port *uart = dev_id;
+	unsigned short irqstat;
+
+	uart->rx_dma_nrows++;
+	if (uart->rx_dma_nrows == DMA_RX_YCOUNT) {
+		uart->rx_dma_nrows = 0;
+		uart->rx_dma_buf.tail = DMA_RX_XCOUNT*DMA_RX_YCOUNT;
+		bfin_serial_dma_rx_chars(uart);
+		uart->rx_dma_buf.head = uart->rx_dma_buf.tail = 0;
+	}
+	spin_lock(&uart->port.lock);
+	irqstat = get_dma_curr_irqstat(uart->rx_dma_channel);
+	clear_dma_irqstat(uart->rx_dma_channel);
+
+	spin_unlock(&uart->port.lock);
+	return IRQ_HANDLED;
+}
+#endif
+
+/*
+ * Return TIOCSER_TEMT when transmitter is not busy.
+ */
+static unsigned int bfin_serial_tx_empty(struct uart_port *port)
+{
+	struct bfin_serial_port *uart = (struct bfin_serial_port *)port;
+	unsigned short lsr;
+
+	lsr = UART_GET_LSR(uart);
+	if (lsr & TEMT)
+		return TIOCSER_TEMT;
+	else
+		return 0;
+}
+
+static unsigned int bfin_serial_get_mctrl(struct uart_port *port)
+{
+#ifdef CONFIG_SERIAL_BFIN_CTSRTS
+	struct bfin_serial_port *uart = (struct bfin_serial_port *)port;
+	if (uart->cts_pin < 0)
+		return TIOCM_CTS | TIOCM_DSR | TIOCM_CAR;
+
+	if (gpio_get_value(uart->cts_pin))
+		return TIOCM_DSR | TIOCM_CAR;
+	else
+#endif
+		return TIOCM_CTS | TIOCM_DSR | TIOCM_CAR;
+}
+
+static void bfin_serial_set_mctrl(struct uart_port *port, unsigned int mctrl)
+{
+#ifdef CONFIG_SERIAL_BFIN_CTSRTS
+	struct bfin_serial_port *uart = (struct bfin_serial_port *)port;
+	if (uart->rts_pin < 0)
+		return;
+
+	if (mctrl & TIOCM_RTS)
+		gpio_set_value(uart->rts_pin, 0);
+	else
+		gpio_set_value(uart->rts_pin, 1);
+#endif
+}
+
+/*
+ * Handle any change of modem status signal since we were last called.
+ */
+static void bfin_serial_mctrl_check(struct bfin_serial_port *uart)
+{
+#ifdef CONFIG_SERIAL_BFIN_CTSRTS
+	unsigned int status;
+# ifdef CONFIG_SERIAL_BFIN_DMA
+	struct uart_info *info = uart->port.info;
+	struct tty_struct *tty = info->tty;
+
+	status = bfin_serial_get_mctrl(&uart->port);
+	if (!(status & TIOCM_CTS)) {
+		tty->hw_stopped = 1;
+	} else {
+		tty->hw_stopped = 0;
+	}
+# else
+	status = bfin_serial_get_mctrl(&uart->port);
+	uart_handle_cts_change(&uart->port, status & TIOCM_CTS);
+	if (!(status & TIOCM_CTS))
+		schedule_work(&uart->cts_workqueue);
+# endif
+#endif
+}
+
+/*
+ * Interrupts are always disabled.
+ */
+static void bfin_serial_break_ctl(struct uart_port *port, int break_state)
+{
+}
+
+static int bfin_serial_startup(struct uart_port *port)
+{
+	struct bfin_serial_port *uart = (struct bfin_serial_port *)port;
+
+#ifdef CONFIG_SERIAL_BFIN_DMA
+	dma_addr_t dma_handle;
+
+	if (request_dma(uart->rx_dma_channel, "BFIN_UART_RX") < 0) {
+		printk(KERN_NOTICE "Unable to attach Blackfin UART RX DMA channel\n");
+		return -EBUSY;
+	}
+
+	if (request_dma(uart->tx_dma_channel, "BFIN_UART_TX") < 0) {
+		printk(KERN_NOTICE "Unable to attach Blackfin UART TX DMA channel\n");
+		free_dma(uart->rx_dma_channel);
+		return -EBUSY;
+	}
+
+	set_dma_callback(uart->rx_dma_channel, bfin_serial_dma_rx_int, uart);
+	set_dma_callback(uart->tx_dma_channel, bfin_serial_dma_tx_int, uart);
+
+	uart->rx_dma_buf.buf = (unsigned char *)dma_alloc_coherent(NULL, PAGE_SIZE, &dma_handle, GFP_DMA);
+	uart->rx_dma_buf.head = 0;
+	uart->rx_dma_buf.tail = 0;
+	uart->rx_dma_nrows = 0;
+
+	set_dma_config(uart->rx_dma_channel,
+		set_bfin_dma_config(DIR_WRITE, DMA_FLOW_AUTO,
+				INTR_ON_ROW, DIMENSION_2D,
+				DATA_SIZE_8));
+	set_dma_x_count(uart->rx_dma_channel, DMA_RX_XCOUNT);
+	set_dma_x_modify(uart->rx_dma_channel, 1);
+	set_dma_y_count(uart->rx_dma_channel, DMA_RX_YCOUNT);
+	set_dma_y_modify(uart->rx_dma_channel, 1);
+	set_dma_start_addr(uart->rx_dma_channel, (unsigned long)uart->rx_dma_buf.buf);
+	enable_dma(uart->rx_dma_channel);
+
+	uart->rx_dma_timer.data = (unsigned long)(uart);
+	uart->rx_dma_timer.function = (void *)bfin_serial_rx_dma_timeout;
+	uart->rx_dma_timer.expires = jiffies + DMA_RX_FLUSH_JIFFIES;
+	add_timer(&(uart->rx_dma_timer));
+#else
+	if (request_irq
+	    (uart->port.irq, bfin_serial_int, IRQF_DISABLED,
+	     "BFIN_UART_RX", uart)) {
+		printk(KERN_NOTICE "Unable to attach BlackFin UART RX interrupt\n");
+		return -EBUSY;
+	}
+
+	if (request_irq
+	    (uart->port.irq+1, bfin_serial_int, IRQF_DISABLED,
+	     "BFIN_UART_TX", uart)) {
+		printk(KERN_NOTICE "Unable to attach BlackFin UART TX interrupt\n");
+		free_irq(uart->port.irq, uart);
+		return -EBUSY;
+	}
+#endif
+	UART_PUT_IER(uart, UART_GET_IER(uart) | ERBFI);
+	return 0;
+}
+
+static void bfin_serial_shutdown(struct uart_port *port)
+{
+	struct bfin_serial_port *uart = (struct bfin_serial_port *)port;
+
+#ifdef CONFIG_SERIAL_BFIN_DMA
+	disable_dma(uart->tx_dma_channel);
+	free_dma(uart->tx_dma_channel);
+	disable_dma(uart->rx_dma_channel);
+	free_dma(uart->rx_dma_channel);
+	del_timer(&(uart->rx_dma_timer));
+#else
+	free_irq(uart->port.irq, uart);
+	free_irq(uart->port.irq+1, uart);
+#endif
+}
+
+static void
+bfin_serial_set_termios(struct uart_port *port, struct ktermios *termios,
+		   struct ktermios *old)
+{
+	struct bfin_serial_port *uart = (struct bfin_serial_port *)port;
+	unsigned long flags;
+	unsigned int baud, quot;
+	unsigned short val, ier, lsr, lcr = 0;
+
+	switch (termios->c_cflag & CSIZE) {
+	case CS8:
+		lcr = WLS(8);
+		break;
+	case CS7:
+		lcr = WLS(7);
+		break;
+	case CS6:
+		lcr = WLS(6);
+		break;
+	case CS5:
+		lcr = WLS(5);
+		break;
+	default:
+		printk(KERN_ERR "%s: word lengh not supported\n",
+			__FUNCTION__);
+	}
+
+	if (termios->c_cflag & CSTOPB)
+		lcr |= STB;
+	if (termios->c_cflag & PARENB) {
+		lcr |= PEN;
+		if (!(termios->c_cflag & PARODD))
+			lcr |= EPS;
+	}
+
+	/* These controls are not implemented for this port */
+	termios->c_iflag |= INPCK | BRKINT | PARMRK;
+	termios->c_iflag &= ~(IGNPAR | IGNBRK);
+
+	/* These controls are not implemented for this port */
+	termios->c_iflag |= INPCK | BRKINT | PARMRK;
+	termios->c_iflag &= ~(IGNPAR | IGNBRK);
+
+	baud = uart_get_baud_rate(port, termios, old, 0, port->uartclk/16);
+	quot = uart_get_divisor(port, baud);
+	spin_lock_irqsave(&uart->port.lock, flags);
+
+	do {
+		lsr = UART_GET_LSR(uart);
+	} while (!(lsr & TEMT));
+
+	/* Disable UART */
+	ier = UART_GET_IER(uart);
+	UART_PUT_IER(uart, 0);
+
+	/* Set DLAB in LCR to Access DLL and DLH */
+	val = UART_GET_LCR(uart);
+	val |= DLAB;
+	UART_PUT_LCR(uart, val);
+	SSYNC();
+
+	UART_PUT_DLL(uart, quot & 0xFF);
+	SSYNC();
+	UART_PUT_DLH(uart, (quot >> 8) & 0xFF);
+	SSYNC();
+
+	/* Clear DLAB in LCR to Access THR RBR IER */
+	val = UART_GET_LCR(uart);
+	val &= ~DLAB;
+	UART_PUT_LCR(uart, val);
+	SSYNC();
+
+	UART_PUT_LCR(uart, lcr);
+
+	/* Enable UART */
+	UART_PUT_IER(uart, ier);
+
+	val = UART_GET_GCTL(uart);
+	val |= UCEN;
+	UART_PUT_GCTL(uart, val);
+
+	spin_unlock_irqrestore(&uart->port.lock, flags);
+}
+
+static const char *bfin_serial_type(struct uart_port *port)
+{
+	struct bfin_serial_port *uart = (struct bfin_serial_port *)port;
+
+	return uart->port.type == PORT_BFIN ? "BFIN-UART" : NULL;
+}
+
+/*
+ * Release the memory region(s) being used by 'port'.
+ */
+static void bfin_serial_release_port(struct uart_port *port)
+{
+}
+
+/*
+ * Request the memory region(s) being used by 'port'.
+ */
+static int bfin_serial_request_port(struct uart_port *port)
+{
+	return 0;
+}
+
+/*
+ * Configure/autoconfigure the port.
+ */
+static void bfin_serial_config_port(struct uart_port *port, int flags)
+{
+	struct bfin_serial_port *uart = (struct bfin_serial_port *)port;
+
+	if (flags & UART_CONFIG_TYPE &&
+	    bfin_serial_request_port(&uart->port) == 0)
+		uart->port.type = PORT_BFIN;
+}
+
+/*
+ * Verify the new serial_struct (for TIOCSSERIAL).
+ * The only change we allow are to the flags and type, and
+ * even then only between PORT_BFIN and PORT_UNKNOWN
+ */
+static int
+bfin_serial_verify_port(struct uart_port *port, struct serial_struct *ser)
+{
+	return 0;
+}
+
+static struct uart_ops bfin_serial_pops = {
+	.tx_empty	= bfin_serial_tx_empty,
+	.set_mctrl	= bfin_serial_set_mctrl,
+	.get_mctrl	= bfin_serial_get_mctrl,
+	.stop_tx	= bfin_serial_stop_tx,
+	.start_tx	= bfin_serial_start_tx,
+	.stop_rx	= bfin_serial_stop_rx,
+	.enable_ms	= bfin_serial_enable_ms,
+	.break_ctl	= bfin_serial_break_ctl,
+	.startup	= bfin_serial_startup,
+	.shutdown	= bfin_serial_shutdown,
+	.set_termios	= bfin_serial_set_termios,
+	.type		= bfin_serial_type,
+	.release_port	= bfin_serial_release_port,
+	.request_port	= bfin_serial_request_port,
+	.config_port	= bfin_serial_config_port,
+	.verify_port	= bfin_serial_verify_port,
+};
+
+static void __init bfin_serial_init_ports(void)
+{
+	static int first = 1;
+	int i;
+
+	if (!first)
+		return;
+	first = 0;
+
+	for (i = 0; i < nr_ports; i++) {
+		bfin_serial_ports[i].port.uartclk   = get_sclk();
+		bfin_serial_ports[i].port.ops       = &bfin_serial_pops;
+		bfin_serial_ports[i].port.line      = i;
+		bfin_serial_ports[i].port.iotype    = UPIO_MEM;
+		bfin_serial_ports[i].port.membase   =
+			(void __iomem *)bfin_serial_resource[i].uart_base_addr;
+		bfin_serial_ports[i].port.mapbase   =
+			bfin_serial_resource[i].uart_base_addr;
+		bfin_serial_ports[i].port.irq       =
+			bfin_serial_resource[i].uart_irq;
+		bfin_serial_ports[i].port.flags     = UPF_BOOT_AUTOCONF;
+#ifdef CONFIG_SERIAL_BFIN_DMA
+		bfin_serial_ports[i].tx_done	    = 1;
+		bfin_serial_ports[i].tx_count	    = 0;
+		bfin_serial_ports[i].tx_dma_channel =
+			bfin_serial_resource[i].uart_tx_dma_channel;
+		bfin_serial_ports[i].rx_dma_channel =
+			bfin_serial_resource[i].uart_rx_dma_channel;
+		init_timer(&(bfin_serial_ports[i].rx_dma_timer));
+#else
+		INIT_WORK(&bfin_serial_ports[i].cts_workqueue, bfin_serial_do_work);
+#endif
+#ifdef CONFIG_SERIAL_BFIN_CTSRTS
+		bfin_serial_ports[i].cts_pin	    =
+			bfin_serial_resource[i].uart_cts_pin;
+		bfin_serial_ports[i].rts_pin	    =
+			bfin_serial_resource[i].uart_rts_pin;
+#endif
+		bfin_serial_hw_init(&bfin_serial_ports[i]);
+
+	}
+}
+
+#ifdef CONFIG_SERIAL_BFIN_CONSOLE
+static void bfin_serial_console_putchar(struct uart_port *port, int ch)
+{
+	struct bfin_serial_port *uart = (struct bfin_serial_port *)port;
+	while (!(UART_GET_LSR(uart)))
+		barrier();
+	UART_PUT_CHAR(uart, ch);
+	SSYNC();
+}
+
+/*
+ * Interrupts are disabled on entering
+ */
+static void
+bfin_serial_console_write(struct console *co, const char *s, unsigned int count)
+{
+	struct bfin_serial_port *uart = &bfin_serial_ports[co->index];
+	int flags = 0;
+
+	spin_lock_irqsave(&uart->port.lock, flags);
+	uart_console_write(&uart->port, s, count, bfin_serial_console_putchar);
+	spin_unlock_irqrestore(&uart->port.lock, flags);
+
+}
+
+/*
+ * If the port was already initialised (eg, by a boot loader),
+ * try to determine the current setup.
+ */
+static void __init
+bfin_serial_console_get_options(struct bfin_serial_port *uart, int *baud,
+			   int *parity, int *bits)
+{
+	unsigned short status;
+
+	status = UART_GET_IER(uart) & (ERBFI | ETBEI);
+	if (status == (ERBFI | ETBEI)) {
+		/* ok, the port was enabled */
+		unsigned short lcr, val;
+		unsigned short dlh, dll;
+
+		lcr = UART_GET_LCR(uart);
+
+		*parity = 'n';
+		if (lcr & PEN) {
+			if (lcr & EPS)
+				*parity = 'e';
+			else
+				*parity = 'o';
+		}
+		switch (lcr & 0x03) {
+			case 0:	*bits = 5; break;
+			case 1:	*bits = 6; break;
+			case 2:	*bits = 7; break;
+			case 3:	*bits = 8; break;
+		}
+		/* Set DLAB in LCR to Access DLL and DLH */
+		val = UART_GET_LCR(uart);
+		val |= DLAB;
+		UART_PUT_LCR(uart, val);
+
+		dll = UART_GET_DLL(uart);
+		dlh = UART_GET_DLH(uart);
+
+		/* Clear DLAB in LCR to Access THR RBR IER */
+		val = UART_GET_LCR(uart);
+		val &= ~DLAB;
+		UART_PUT_LCR(uart, val);
+
+		*baud = get_sclk() / (16*(dll | dlh << 8));
+	}
+	pr_debug("%s:baud = %d, parity = %c, bits= %d\n", __FUNCTION__, *baud, *parity, *bits);
+}
+
+static int __init
+bfin_serial_console_setup(struct console *co, char *options)
+{
+	struct bfin_serial_port *uart;
+	int baud = 57600;
+	int bits = 8;
+	int parity = 'n';
+#ifdef CONFIG_SERIAL_BFIN_CTSRTS
+	int flow = 'r';
+#else
+	int flow = 'n';
+#endif
+
+	/*
+	 * 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 == -1 || co->index >= nr_ports)
+		co->index = 0;
+	uart = &bfin_serial_ports[co->index];
+
+	if (options)
+		uart_parse_options(options, &baud, &parity, &bits, &flow);
+	else
+		bfin_serial_console_get_options(uart, &baud, &parity, &bits);
+
+	return uart_set_options(&uart->port, co, baud, parity, bits, flow);
+}
+
+static struct uart_driver bfin_serial_reg;
+static struct console bfin_serial_console = {
+	.name		= BFIN_SERIAL_NAME,
+	.write		= bfin_serial_console_write,
+	.device		= uart_console_device,
+	.setup		= bfin_serial_console_setup,
+	.flags		= CON_PRINTBUFFER,
+	.index		= -1,
+	.data		= &bfin_serial_reg,
+};
+
+static int __init bfin_serial_rs_console_init(void)
+{
+	bfin_serial_init_ports();
+	register_console(&bfin_serial_console);
+	return 0;
+}
+console_initcall(bfin_serial_rs_console_init);
+
+#define BFIN_SERIAL_CONSOLE	&bfin_serial_console
+#else
+#define BFIN_SERIAL_CONSOLE	NULL
+#endif
+
+static struct uart_driver bfin_serial_reg = {
+	.owner			= THIS_MODULE,
+	.driver_name		= "bfin-uart",
+	.dev_name		= BFIN_SERIAL_NAME,
+	.major			= BFIN_SERIAL_MAJOR,
+	.minor			= BFIN_SERIAL_MINOR,
+	.nr			= NR_PORTS,
+	.cons			= BFIN_SERIAL_CONSOLE,
+};
+
+static int bfin_serial_suspend(struct platform_device *dev, pm_message_t state)
+{
+	struct bfin_serial_port *uart = platform_get_drvdata(dev);
+
+	if (uart)
+		uart_suspend_port(&bfin_serial_reg, &uart->port);
+
+	return 0;
+}
+
+static int bfin_serial_resume(struct platform_device *dev)
+{
+	struct bfin_serial_port *uart = platform_get_drvdata(dev);
+
+	if (uart)
+		uart_resume_port(&bfin_serial_reg, &uart->port);
+
+	return 0;
+}
+
+static int bfin_serial_probe(struct platform_device *dev)
+{
+	struct resource *res = dev->resource;
+	int i;
+
+	for (i = 0; i < dev->num_resources; i++, res++)
+		if (res->flags & IORESOURCE_MEM)
+			break;
+
+	if (i < dev->num_resources) {
+		for (i = 0; i < nr_ports; i++, res++) {
+			if (bfin_serial_ports[i].port.mapbase != res->start)
+				continue;
+			bfin_serial_ports[i].port.dev = &dev->dev;
+			uart_add_one_port(&bfin_serial_reg, &bfin_serial_ports[i].port);
+			platform_set_drvdata(dev, &bfin_serial_ports[i]);
+		}
+	}
+
+	return 0;
+}
+
+static int bfin_serial_remove(struct platform_device *pdev)
+{
+	struct bfin_serial_port *uart = platform_get_drvdata(pdev);
+
+
+#ifdef CONFIG_SERIAL_BFIN_CTSRTS
+	gpio_free(uart->cts_pin);
+	gpio_free(uart->rts_pin);
+#endif
+
+	platform_set_drvdata(pdev, NULL);
+
+	if (uart)
+		uart_remove_one_port(&bfin_serial_reg, &uart->port);
+
+	return 0;
+}
+
+static struct platform_driver bfin_serial_driver = {
+	.probe		= bfin_serial_probe,
+	.remove		= bfin_serial_remove,
+	.suspend	= bfin_serial_suspend,
+	.resume		= bfin_serial_resume,
+	.driver		= {
+		.name	= "bfin-uart",
+	},
+};
+
+static int __init bfin_serial_init(void)
+{
+	int ret;
+
+	pr_info("Serial: Blackfin serial driver\n");
+
+	bfin_serial_init_ports();
+
+	ret = uart_register_driver(&bfin_serial_reg);
+	if (ret == 0) {
+		ret = platform_driver_register(&bfin_serial_driver);
+		if (ret) {
+			pr_debug("uart register failed\n");
+			uart_unregister_driver(&bfin_serial_reg);
+		}
+	}
+	return ret;
+}
+
+static void __exit bfin_serial_exit(void)
+{
+	platform_driver_unregister(&bfin_serial_driver);
+	uart_unregister_driver(&bfin_serial_reg);
+}
+
+module_init(bfin_serial_init);
+module_exit(bfin_serial_exit);
+
+MODULE_AUTHOR("Aubrey.Li <aubrey.li@analog.com>");
+MODULE_DESCRIPTION("Blackfin generic serial port driver");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS_CHARDEV_MAJOR(BFIN_SERIAL_MAJOR);

include/linux/serial_core.h

@@ -136,6 +136,9 @@
 /* Xilinx uartlite */
 #define PORT_UARTLITE	74
 
+/* Blackfin bf5xx */
+#define PORT_BFIN	75
+
 #ifdef __KERNEL__
 
 #include <linux/compiler.h>