1 files changed, 937 insertions, 0 deletions

diff --git a/drivers/tty/serial/bfin_sport_uart.c b/drivers/tty/serial/bfin_sport_uart.c
new file mode 100644
index 00000000000..4f229703328
--- /dev/null
+++ b/drivers/tty/serial/bfin_sport_uart.c
@@ -0,0 +1,937 @@
+/*
+ * Blackfin On-Chip Sport Emulated UART Driver
+ *
+ * Copyright 2006-2009 Analog Devices Inc.
+ *
+ * Enter bugs at http://blackfin.uclinux.org/
+ *
+ * Licensed under the GPL-2 or later.
+ */
+
+/*
+ * This driver and the hardware supported are in term of EE-191 of ADI.
+ * http://www.analog.com/static/imported-files/application_notes/EE191.pdf 
+ * This application note describe how to implement a UART on a Sharc DSP,
+ * but this driver is implemented on Blackfin Processor.
+ * Transmit Frame Sync is not used by this driver to transfer data out.
+ */
+
+/* #define DEBUG */
+
+#define DRV_NAME "bfin-sport-uart"
+#define DEVICE_NAME	"ttySS"
+#define pr_fmt(fmt) DRV_NAME ": " fmt
+
+#include <linux/module.h>
+#include <linux/ioport.h>
+#include <linux/io.h>
+#include <linux/init.h>
+#include <linux/console.h>
+#include <linux/sysrq.h>
+#include <linux/slab.h>
+#include <linux/platform_device.h>
+#include <linux/tty.h>
+#include <linux/tty_flip.h>
+#include <linux/serial_core.h>
+
+#include <asm/bfin_sport.h>
+#include <asm/delay.h>
+#include <asm/portmux.h>
+
+#include "bfin_sport_uart.h"
+
+struct sport_uart_port {
+	struct uart_port	port;
+	int			err_irq;
+	unsigned short		csize;
+	unsigned short		rxmask;
+	unsigned short		txmask1;
+	unsigned short		txmask2;
+	unsigned char		stopb;
+/*	unsigned char		parib; */
+#ifdef CONFIG_SERIAL_BFIN_SPORT_CTSRTS
+	int cts_pin;
+	int rts_pin;
+#endif
+};
+
+static int sport_uart_tx_chars(struct sport_uart_port *up);
+static void sport_stop_tx(struct uart_port *port);
+
+static inline void tx_one_byte(struct sport_uart_port *up, unsigned int value)
+{
+	pr_debug("%s value:%x, mask1=0x%x, mask2=0x%x\n", __func__, value,
+		up->txmask1, up->txmask2);
+
+	/* Place Start and Stop bits */
+	__asm__ __volatile__ (
+		"%[val] <<= 1;"
+		"%[val] = %[val] & %[mask1];"
+		"%[val] = %[val] | %[mask2];"
+		: [val]"+d"(value)
+		: [mask1]"d"(up->txmask1), [mask2]"d"(up->txmask2)
+		: "ASTAT"
+	);
+	pr_debug("%s value:%x\n", __func__, value);
+
+	SPORT_PUT_TX(up, value);
+}
+
+static inline unsigned char rx_one_byte(struct sport_uart_port *up)
+{
+	unsigned int value;
+	unsigned char extract;
+	u32 tmp_mask1, tmp_mask2, tmp_shift, tmp;
+
+	if ((up->csize + up->stopb) > 7)
+		value = SPORT_GET_RX32(up);
+	else
+		value = SPORT_GET_RX(up);
+
+	pr_debug("%s value:%x, cs=%d, mask=0x%x\n", __func__, value,
+		up->csize, up->rxmask);
+
+	/* Extract data */
+	__asm__ __volatile__ (
+		"%[extr] = 0;"
+		"%[mask1] = %[rxmask];"
+		"%[mask2] = 0x0200(Z);"
+		"%[shift] = 0;"
+		"LSETUP(.Lloop_s, .Lloop_e) LC0 = %[lc];"
+		".Lloop_s:"
+		"%[tmp] = extract(%[val], %[mask1].L)(Z);"
+		"%[tmp] <<= %[shift];"
+		"%[extr] = %[extr] | %[tmp];"
+		"%[mask1] = %[mask1] - %[mask2];"
+		".Lloop_e:"
+		"%[shift] += 1;"
+		: [extr]"=&d"(extract), [shift]"=&d"(tmp_shift), [tmp]"=&d"(tmp),
+		  [mask1]"=&d"(tmp_mask1), [mask2]"=&d"(tmp_mask2)
+		: [val]"d"(value), [rxmask]"d"(up->rxmask), [lc]"a"(up->csize)
+		: "ASTAT", "LB0", "LC0", "LT0"
+	);
+
+	pr_debug("	extract:%x\n", extract);
+	return extract;
+}
+
+static int sport_uart_setup(struct sport_uart_port *up, int size, int baud_rate)
+{
+	int tclkdiv, rclkdiv;
+	unsigned int sclk = get_sclk();
+
+	/* Set TCR1 and TCR2, TFSR is not enabled for uart */
+	SPORT_PUT_TCR1(up, (LATFS | ITFS | TFSR | TLSBIT | ITCLK));
+	SPORT_PUT_TCR2(up, size + 1);
+	pr_debug("%s TCR1:%x, TCR2:%x\n", __func__, SPORT_GET_TCR1(up), SPORT_GET_TCR2(up));
+
+	/* Set RCR1 and RCR2 */
+	SPORT_PUT_RCR1(up, (RCKFE | LARFS | LRFS | RFSR | IRCLK));
+	SPORT_PUT_RCR2(up, (size + 1) * 2 - 1);
+	pr_debug("%s RCR1:%x, RCR2:%x\n", __func__, SPORT_GET_RCR1(up), SPORT_GET_RCR2(up));
+
+	tclkdiv = sclk / (2 * baud_rate) - 1;
+	/* The actual uart baud rate of devices vary between +/-2%. The sport
+	 * RX sample rate should be faster than the double of the worst case,
+	 * otherwise, wrong data are received. So, set sport RX clock to be
+	 * 3% faster.
+	 */
+	rclkdiv = sclk / (2 * baud_rate * 2 * 97 / 100) - 1;
+	SPORT_PUT_TCLKDIV(up, tclkdiv);
+	SPORT_PUT_RCLKDIV(up, rclkdiv);
+	SSYNC();
+	pr_debug("%s sclk:%d, baud_rate:%d, tclkdiv:%d, rclkdiv:%d\n",
+			__func__, sclk, baud_rate, tclkdiv, rclkdiv);
+
+	return 0;
+}
+
+static irqreturn_t sport_uart_rx_irq(int irq, void *dev_id)
+{
+	struct sport_uart_port *up = dev_id;
+	struct tty_port *port = &up->port.state->port;
+	unsigned int ch;
+
+	spin_lock(&up->port.lock);
+
+	while (SPORT_GET_STAT(up) & RXNE) {
+		ch = rx_one_byte(up);
+		up->port.icount.rx++;
+
+		if (!uart_handle_sysrq_char(&up->port, ch))
+			tty_insert_flip_char(port, ch, TTY_NORMAL);
+	}
+
+	spin_unlock(&up->port.lock);
+
+	/* XXX this won't deadlock with lowlat? */
+	tty_flip_buffer_push(port);
+
+	return IRQ_HANDLED;
+}
+
+static irqreturn_t sport_uart_tx_irq(int irq, void *dev_id)
+{
+	struct sport_uart_port *up = dev_id;
+
+	spin_lock(&up->port.lock);
+	sport_uart_tx_chars(up);
+	spin_unlock(&up->port.lock);
+
+	return IRQ_HANDLED;
+}
+
+static irqreturn_t sport_uart_err_irq(int irq, void *dev_id)
+{
+	struct sport_uart_port *up = dev_id;
+	unsigned int stat = SPORT_GET_STAT(up);
+
+	spin_lock(&up->port.lock);
+
+	/* Overflow in RX FIFO */
+	if (stat & ROVF) {
+		up->port.icount.overrun++;
+		tty_insert_flip_char(&up->port.state->port, 0, TTY_OVERRUN);
+		SPORT_PUT_STAT(up, ROVF); /* Clear ROVF bit */
+	}
+	/* These should not happen */
+	if (stat & (TOVF | TUVF | RUVF)) {
+		pr_err("SPORT Error:%s %s %s\n",
+		       (stat & TOVF) ? "TX overflow" : "",
+		       (stat & TUVF) ? "TX underflow" : "",
+		       (stat & RUVF) ? "RX underflow" : "");
+		SPORT_PUT_TCR1(up, SPORT_GET_TCR1(up) & ~TSPEN);
+		SPORT_PUT_RCR1(up, SPORT_GET_RCR1(up) & ~RSPEN);
+	}
+	SSYNC();
+
+	spin_unlock(&up->port.lock);
+	/* XXX we don't push the overrun bit to TTY? */
+
+	return IRQ_HANDLED;
+}
+
+#ifdef CONFIG_SERIAL_BFIN_SPORT_CTSRTS
+static unsigned int sport_get_mctrl(struct uart_port *port)
+{
+	struct sport_uart_port *up = (struct sport_uart_port *)port;
+	if (up->cts_pin < 0)
+		return TIOCM_CTS | TIOCM_DSR | TIOCM_CAR;
+
+	/* CTS PIN is negative assertive. */
+	if (SPORT_UART_GET_CTS(up))
+		return TIOCM_CTS | TIOCM_DSR | TIOCM_CAR;
+	else
+		return TIOCM_DSR | TIOCM_CAR;
+}
+
+static void sport_set_mctrl(struct uart_port *port, unsigned int mctrl)
+{
+	struct sport_uart_port *up = (struct sport_uart_port *)port;
+	if (up->rts_pin < 0)
+		return;
+
+	/* RTS PIN is negative assertive. */
+	if (mctrl & TIOCM_RTS)
+		SPORT_UART_ENABLE_RTS(up);
+	else
+		SPORT_UART_DISABLE_RTS(up);
+}
+
+/*
+ * Handle any change of modem status signal.
+ */
+static irqreturn_t sport_mctrl_cts_int(int irq, void *dev_id)
+{
+	struct sport_uart_port *up = (struct sport_uart_port *)dev_id;
+	unsigned int status;
+
+	status = sport_get_mctrl(&up->port);
+	uart_handle_cts_change(&up->port, status & TIOCM_CTS);
+
+	return IRQ_HANDLED;
+}
+#else
+static unsigned int sport_get_mctrl(struct uart_port *port)
+{
+	pr_debug("%s enter\n", __func__);
+	return TIOCM_CTS | TIOCM_CD | TIOCM_DSR;
+}
+
+static void sport_set_mctrl(struct uart_port *port, unsigned int mctrl)
+{
+	pr_debug("%s enter\n", __func__);
+}
+#endif
+
+/* Reqeust IRQ, Setup clock */
+static int sport_startup(struct uart_port *port)
+{
+	struct sport_uart_port *up = (struct sport_uart_port *)port;
+	int ret;
+
+	pr_debug("%s enter\n", __func__);
+	ret = request_irq(up->port.irq, sport_uart_rx_irq, 0,
+		"SPORT_UART_RX", up);
+	if (ret) {
+		dev_err(port->dev, "unable to request SPORT RX interrupt\n");
+		return ret;
+	}
+
+	ret = request_irq(up->port.irq+1, sport_uart_tx_irq, 0,
+		"SPORT_UART_TX", up);
+	if (ret) {
+		dev_err(port->dev, "unable to request SPORT TX interrupt\n");
+		goto fail1;
+	}
+
+	ret = request_irq(up->err_irq, sport_uart_err_irq, 0,
+		"SPORT_UART_STATUS", up);
+	if (ret) {
+		dev_err(port->dev, "unable to request SPORT status interrupt\n");
+		goto fail2;
+	}
+
+#ifdef CONFIG_SERIAL_BFIN_SPORT_CTSRTS
+	if (up->cts_pin >= 0) {
+		if (request_irq(gpio_to_irq(up->cts_pin),
+			sport_mctrl_cts_int,
+			IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING |
+			0, "BFIN_SPORT_UART_CTS", up)) {
+			up->cts_pin = -1;
+			dev_info(port->dev, "Unable to attach BlackFin UART over SPORT CTS interrupt. So, disable it.\n");
+		}
+	}
+	if (up->rts_pin >= 0) {
+		if (gpio_request(up->rts_pin, DRV_NAME)) {
+			dev_info(port->dev, "fail to request RTS PIN at GPIO_%d\n", up->rts_pin);
+			up->rts_pin = -1;
+		} else
+			gpio_direction_output(up->rts_pin, 0);
+	}
+#endif
+
+	return 0;
+ fail2:
+	free_irq(up->port.irq+1, up);
+ fail1:
+	free_irq(up->port.irq, up);
+
+	return ret;
+}
+
+/*
+ * sport_uart_tx_chars
+ *
+ * ret 1 means need to enable sport.
+ * ret 0 means do nothing.
+ */
+static int sport_uart_tx_chars(struct sport_uart_port *up)
+{
+	struct circ_buf *xmit = &up->port.state->xmit;
+
+	if (SPORT_GET_STAT(up) & TXF)
+		return 0;
+
+	if (up->port.x_char) {
+		tx_one_byte(up, up->port.x_char);
+		up->port.icount.tx++;
+		up->port.x_char = 0;
+		return 1;
+	}
+
+	if (uart_circ_empty(xmit) || uart_tx_stopped(&up->port)) {
+		/* The waiting loop to stop SPORT TX from TX interrupt is
+		 * too long. This may block SPORT RX interrupts and cause
+		 * RX FIFO overflow. So, do stop sport TX only after the last
+		 * char in TX FIFO is moved into the shift register.
+		 */
+		if (SPORT_GET_STAT(up) & TXHRE)
+			sport_stop_tx(&up->port);
+		return 0;
+	}
+
+	while(!(SPORT_GET_STAT(up) & TXF) && !uart_circ_empty(xmit)) {
+		tx_one_byte(up, xmit->buf[xmit->tail]);
+		xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE -1);
+		up->port.icount.tx++;
+	}
+
+	if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
+		uart_write_wakeup(&up->port);
+
+	return 1;
+}
+
+static unsigned int sport_tx_empty(struct uart_port *port)
+{
+	struct sport_uart_port *up = (struct sport_uart_port *)port;
+	unsigned int stat;
+
+	stat = SPORT_GET_STAT(up);
+	pr_debug("%s stat:%04x\n", __func__, stat);
+	if (stat & TXHRE) {
+		return TIOCSER_TEMT;
+	} else
+		return 0;
+}
+
+static void sport_stop_tx(struct uart_port *port)
+{
+	struct sport_uart_port *up = (struct sport_uart_port *)port;
+
+	pr_debug("%s enter\n", __func__);
+
+	if (!(SPORT_GET_TCR1(up) & TSPEN))
+		return;
+
+	/* Although the hold register is empty, last byte is still in shift
+	 * register and not sent out yet. So, put a dummy data into TX FIFO.
+	 * Then, sport tx stops when last byte is shift out and the dummy
+	 * data is moved into the shift register.
+	 */
+	SPORT_PUT_TX(up, 0xffff);
+	while (!(SPORT_GET_STAT(up) & TXHRE))
+		cpu_relax();
+
+	SPORT_PUT_TCR1(up, (SPORT_GET_TCR1(up) & ~TSPEN));
+	SSYNC();
+
+	return;
+}
+
+static void sport_start_tx(struct uart_port *port)
+{
+	struct sport_uart_port *up = (struct sport_uart_port *)port;
+
+	pr_debug("%s enter\n", __func__);
+
+	/* Write data into SPORT FIFO before enable SPROT to transmit */
+	if (sport_uart_tx_chars(up)) {
+		/* Enable transmit, then an interrupt will generated */
+		SPORT_PUT_TCR1(up, (SPORT_GET_TCR1(up) | TSPEN));
+		SSYNC();
+	}
+
+	pr_debug("%s exit\n", __func__);
+}
+
+static void sport_stop_rx(struct uart_port *port)
+{
+	struct sport_uart_port *up = (struct sport_uart_port *)port;
+
+	pr_debug("%s enter\n", __func__);
+	/* Disable sport to stop rx */
+	SPORT_PUT_RCR1(up, (SPORT_GET_RCR1(up) & ~RSPEN));
+	SSYNC();
+}
+
+static void sport_enable_ms(struct uart_port *port)
+{
+	pr_debug("%s enter\n", __func__);
+}
+
+static void sport_break_ctl(struct uart_port *port, int break_state)
+{
+	pr_debug("%s enter\n", __func__);
+}
+
+static void sport_shutdown(struct uart_port *port)
+{
+	struct sport_uart_port *up = (struct sport_uart_port *)port;
+
+	dev_dbg(port->dev, "%s enter\n", __func__);
+
+	/* Disable sport */
+	SPORT_PUT_TCR1(up, (SPORT_GET_TCR1(up) & ~TSPEN));
+	SPORT_PUT_RCR1(up, (SPORT_GET_RCR1(up) & ~RSPEN));
+	SSYNC();
+
+	free_irq(up->port.irq, up);
+	free_irq(up->port.irq+1, up);
+	free_irq(up->err_irq, up);
+#ifdef CONFIG_SERIAL_BFIN_SPORT_CTSRTS
+	if (up->cts_pin >= 0)
+		free_irq(gpio_to_irq(up->cts_pin), up);
+	if (up->rts_pin >= 0)
+		gpio_free(up->rts_pin);
+#endif
+}
+
+static const char *sport_type(struct uart_port *port)
+{
+	struct sport_uart_port *up = (struct sport_uart_port *)port;
+
+	pr_debug("%s enter\n", __func__);
+	return up->port.type == PORT_BFIN_SPORT ? "BFIN-SPORT-UART" : NULL;
+}
+
+static void sport_release_port(struct uart_port *port)
+{
+	pr_debug("%s enter\n", __func__);
+}
+
+static int sport_request_port(struct uart_port *port)
+{
+	pr_debug("%s enter\n", __func__);
+	return 0;
+}
+
+static void sport_config_port(struct uart_port *port, int flags)
+{
+	struct sport_uart_port *up = (struct sport_uart_port *)port;
+
+	pr_debug("%s enter\n", __func__);
+	up->port.type = PORT_BFIN_SPORT;
+}
+
+static int sport_verify_port(struct uart_port *port, struct serial_struct *ser)
+{
+	pr_debug("%s enter\n", __func__);
+	return 0;
+}
+
+static void sport_set_termios(struct uart_port *port,
+		struct ktermios *termios, struct ktermios *old)
+{
+	struct sport_uart_port *up = (struct sport_uart_port *)port;
+	unsigned long flags;
+	int i;
+
+	pr_debug("%s enter, c_cflag:%08x\n", __func__, termios->c_cflag);
+
+	switch (termios->c_cflag & CSIZE) {
+	case CS8:
+		up->csize = 8;
+		break;
+	case CS7:
+		up->csize = 7;
+		break;
+	case CS6:
+		up->csize = 6;
+		break;
+	case CS5:
+		up->csize = 5;
+		break;
+	default:
+		pr_warning("requested word length not supported\n");
+	}
+
+	if (termios->c_cflag & CSTOPB) {
+		up->stopb = 1;
+	}
+	if (termios->c_cflag & PARENB) {
+		pr_warning("PAREN bits is not supported yet\n");
+		/* up->parib = 1; */
+	}
+
+	spin_lock_irqsave(&up->port.lock, flags);
+
+	port->read_status_mask = 0;
+
+	/*
+	 * Characters to ignore
+	 */
+	port->ignore_status_mask = 0;
+
+	/* RX extract mask */
+	up->rxmask = 0x01 | (((up->csize + up->stopb) * 2 - 1) << 0x8);
+	/* TX masks, 8 bit data and 1 bit stop for example:
+	 * mask1 = b#0111111110
+	 * mask2 = b#1000000000
+	 */
+	for (i = 0, up->txmask1 = 0; i < up->csize; i++)
+		up->txmask1 |= (1<<i);
+	up->txmask2 = (1<<i);
+	if (up->stopb) {
+		++i;
+		up->txmask2 |= (1<<i);
+	}
+	up->txmask1 <<= 1;
+	up->txmask2 <<= 1;
+	/* uart baud rate */
+	port->uartclk = uart_get_baud_rate(port, termios, old, 0, get_sclk()/16);
+
+	/* Disable UART */
+	SPORT_PUT_TCR1(up, SPORT_GET_TCR1(up) & ~TSPEN);
+	SPORT_PUT_RCR1(up, SPORT_GET_RCR1(up) & ~RSPEN);
+
+	sport_uart_setup(up, up->csize + up->stopb, port->uartclk);
+
+	/* driver TX line high after config, one dummy data is
+	 * necessary to stop sport after shift one byte
+	 */
+	SPORT_PUT_TX(up, 0xffff);
+	SPORT_PUT_TX(up, 0xffff);
+	SPORT_PUT_TCR1(up, (SPORT_GET_TCR1(up) | TSPEN));
+	SSYNC();
+	while (!(SPORT_GET_STAT(up) & TXHRE))
+		cpu_relax();
+	SPORT_PUT_TCR1(up, SPORT_GET_TCR1(up) & ~TSPEN);
+	SSYNC();
+
+	/* Port speed changed, update the per-port timeout. */
+	uart_update_timeout(port, termios->c_cflag, port->uartclk);
+
+	/* Enable sport rx */
+	SPORT_PUT_RCR1(up, SPORT_GET_RCR1(up) | RSPEN);
+	SSYNC();
+
+	spin_unlock_irqrestore(&up->port.lock, flags);
+}
+
+struct uart_ops sport_uart_ops = {
+	.tx_empty	= sport_tx_empty,
+	.set_mctrl	= sport_set_mctrl,
+	.get_mctrl	= sport_get_mctrl,
+	.stop_tx	= sport_stop_tx,
+	.start_tx	= sport_start_tx,
+	.stop_rx	= sport_stop_rx,
+	.enable_ms	= sport_enable_ms,
+	.break_ctl	= sport_break_ctl,
+	.startup	= sport_startup,
+	.shutdown	= sport_shutdown,
+	.set_termios	= sport_set_termios,
+	.type		= sport_type,
+	.release_port	= sport_release_port,
+	.request_port	= sport_request_port,
+	.config_port	= sport_config_port,
+	.verify_port	= sport_verify_port,
+};
+
+#define BFIN_SPORT_UART_MAX_PORTS 4
+
+static struct sport_uart_port *bfin_sport_uart_ports[BFIN_SPORT_UART_MAX_PORTS];
+
+#ifdef CONFIG_SERIAL_BFIN_SPORT_CONSOLE
+#define CLASS_BFIN_SPORT_CONSOLE	"bfin-sport-console"
+
+static int __init
+sport_uart_console_setup(struct console *co, char *options)
+{
+	struct sport_uart_port *up;
+	int baud = 57600;
+	int bits = 8;
+	int parity = 'n';
+# ifdef CONFIG_SERIAL_BFIN_SPORT_CTSRTS
+	int flow = 'r';
+# else
+	int flow = 'n';
+# endif
+
+	/* Check whether an invalid uart number has been specified */
+	if (co->index < 0 || co->index >= BFIN_SPORT_UART_MAX_PORTS)
+		return -ENODEV;
+
+	up = bfin_sport_uart_ports[co->index];
+	if (!up)
+		return -ENODEV;
+
+	if (options)
+		uart_parse_options(options, &baud, &parity, &bits, &flow);
+
+	return uart_set_options(&up->port, co, baud, parity, bits, flow);
+}
+
+static void sport_uart_console_putchar(struct uart_port *port, int ch)
+{
+	struct sport_uart_port *up = (struct sport_uart_port *)port;
+
+	while (SPORT_GET_STAT(up) & TXF)
+		barrier();
+
+	tx_one_byte(up, ch);
+}
+
+/*
+ * Interrupts are disabled on entering
+ */
+static void
+sport_uart_console_write(struct console *co, const char *s, unsigned int count)
+{
+	struct sport_uart_port *up = bfin_sport_uart_ports[co->index];
+	unsigned long flags;
+
+	spin_lock_irqsave(&up->port.lock, flags);
+
+	if (SPORT_GET_TCR1(up) & TSPEN)
+		uart_console_write(&up->port, s, count, sport_uart_console_putchar);
+	else {
+		/* dummy data to start sport */
+		while (SPORT_GET_STAT(up) & TXF)
+			barrier();
+		SPORT_PUT_TX(up, 0xffff);
+		/* Enable transmit, then an interrupt will generated */
+		SPORT_PUT_TCR1(up, (SPORT_GET_TCR1(up) | TSPEN));
+		SSYNC();
+
+		uart_console_write(&up->port, s, count, sport_uart_console_putchar);
+
+		/* Although the hold register is empty, last byte is still in shift
+		 * register and not sent out yet. So, put a dummy data into TX FIFO.
+		 * Then, sport tx stops when last byte is shift out and the dummy
+		 * data is moved into the shift register.
+		 */
+		while (SPORT_GET_STAT(up) & TXF)
+			barrier();
+		SPORT_PUT_TX(up, 0xffff);
+		while (!(SPORT_GET_STAT(up) & TXHRE))
+			barrier();
+
+		/* Stop sport tx transfer */
+		SPORT_PUT_TCR1(up, (SPORT_GET_TCR1(up) & ~TSPEN));
+		SSYNC();
+	}
+
+	spin_unlock_irqrestore(&up->port.lock, flags);
+}
+
+static struct uart_driver sport_uart_reg;
+
+static struct console sport_uart_console = {
+	.name		= DEVICE_NAME,
+	.write		= sport_uart_console_write,
+	.device		= uart_console_device,
+	.setup		= sport_uart_console_setup,
+	.flags		= CON_PRINTBUFFER,
+	.index		= -1,
+	.data		= &sport_uart_reg,
+};
+
+#define SPORT_UART_CONSOLE	(&sport_uart_console)
+#else
+#define SPORT_UART_CONSOLE	NULL
+#endif /* CONFIG_SERIAL_BFIN_SPORT_CONSOLE */
+
+
+static struct uart_driver sport_uart_reg = {
+	.owner		= THIS_MODULE,
+	.driver_name	= DRV_NAME,
+	.dev_name	= DEVICE_NAME,
+	.major		= 204,
+	.minor		= 84,
+	.nr		= BFIN_SPORT_UART_MAX_PORTS,
+	.cons		= SPORT_UART_CONSOLE,
+};
+
+#ifdef CONFIG_PM
+static int sport_uart_suspend(struct device *dev)
+{
+	struct sport_uart_port *sport = dev_get_drvdata(dev);
+
+	dev_dbg(dev, "%s enter\n", __func__);
+	if (sport)
+		uart_suspend_port(&sport_uart_reg, &sport->port);
+
+	return 0;
+}
+
+static int sport_uart_resume(struct device *dev)
+{
+	struct sport_uart_port *sport = dev_get_drvdata(dev);
+
+	dev_dbg(dev, "%s enter\n", __func__);
+	if (sport)
+		uart_resume_port(&sport_uart_reg, &sport->port);
+
+	return 0;
+}
+
+static struct dev_pm_ops bfin_sport_uart_dev_pm_ops = {
+	.suspend	= sport_uart_suspend,
+	.resume		= sport_uart_resume,
+};
+#endif
+
+static int sport_uart_probe(struct platform_device *pdev)
+{
+	struct resource *res;
+	struct sport_uart_port *sport;
+	int ret = 0;
+
+	dev_dbg(&pdev->dev, "%s enter\n", __func__);
+
+	if (pdev->id < 0 || pdev->id >= BFIN_SPORT_UART_MAX_PORTS) {
+		dev_err(&pdev->dev, "Wrong sport uart platform device id.\n");
+		return -ENOENT;
+	}
+
+	if (bfin_sport_uart_ports[pdev->id] == NULL) {
+		bfin_sport_uart_ports[pdev->id] =
+			kzalloc(sizeof(struct sport_uart_port), GFP_KERNEL);
+		sport = bfin_sport_uart_ports[pdev->id];
+		if (!sport) {
+			dev_err(&pdev->dev,
+				"Fail to malloc sport_uart_port\n");
+			return -ENOMEM;
+		}
+
+		ret = peripheral_request_list(dev_get_platdata(&pdev->dev),
+						DRV_NAME);
+		if (ret) {
+			dev_err(&pdev->dev,
+				"Fail to request SPORT peripherals\n");
+			goto out_error_free_mem;
+		}
+
+		spin_lock_init(&sport->port.lock);
+		sport->port.fifosize  = SPORT_TX_FIFO_SIZE,
+		sport->port.ops       = &sport_uart_ops;
+		sport->port.line      = pdev->id;
+		sport->port.iotype    = UPIO_MEM;
+		sport->port.flags     = UPF_BOOT_AUTOCONF;
+
+		res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+		if (res == NULL) {
+			dev_err(&pdev->dev, "Cannot get IORESOURCE_MEM\n");
+			ret = -ENOENT;
+			goto out_error_free_peripherals;
+		}
+
+		sport->port.membase = ioremap(res->start, resource_size(res));
+		if (!sport->port.membase) {
+			dev_err(&pdev->dev, "Cannot map sport IO\n");
+			ret = -ENXIO;
+			goto out_error_free_peripherals;
+		}
+		sport->port.mapbase = res->start;
+
+		sport->port.irq = platform_get_irq(pdev, 0);
+		if ((int)sport->port.irq < 0) {
+			dev_err(&pdev->dev, "No sport RX/TX IRQ specified\n");
+			ret = -ENOENT;
+			goto out_error_unmap;
+		}
+
+		sport->err_irq = platform_get_irq(pdev, 1);
+		if (sport->err_irq < 0) {
+			dev_err(&pdev->dev, "No sport status IRQ specified\n");
+			ret = -ENOENT;
+			goto out_error_unmap;
+		}
+#ifdef CONFIG_SERIAL_BFIN_SPORT_CTSRTS
+		res = platform_get_resource(pdev, IORESOURCE_IO, 0);
+		if (res == NULL)
+			sport->cts_pin = -1;
+		else {
+			sport->cts_pin = res->start;
+			sport->port.flags |= ASYNC_CTS_FLOW;
+		}
+
+		res = platform_get_resource(pdev, IORESOURCE_IO, 1);
+		if (res == NULL)
+			sport->rts_pin = -1;
+		else
+			sport->rts_pin = res->start;
+#endif
+	}
+
+#ifdef CONFIG_SERIAL_BFIN_SPORT_CONSOLE
+	if (!is_early_platform_device(pdev)) {
+#endif
+		sport = bfin_sport_uart_ports[pdev->id];
+		sport->port.dev = &pdev->dev;
+		dev_set_drvdata(&pdev->dev, sport);
+		ret = uart_add_one_port(&sport_uart_reg, &sport->port);
+#ifdef CONFIG_SERIAL_BFIN_SPORT_CONSOLE
+	}
+#endif
+	if (!ret)
+		return 0;
+
+	if (sport) {
+out_error_unmap:
+		iounmap(sport->port.membase);
+out_error_free_peripherals:
+		peripheral_free_list(dev_get_platdata(&pdev->dev));
+out_error_free_mem:
+		kfree(sport);
+		bfin_sport_uart_ports[pdev->id] = NULL;
+	}
+
+	return ret;
+}
+
+static int sport_uart_remove(struct platform_device *pdev)
+{
+	struct sport_uart_port *sport = platform_get_drvdata(pdev);
+
+	dev_dbg(&pdev->dev, "%s enter\n", __func__);
+	dev_set_drvdata(&pdev->dev, NULL);
+
+	if (sport) {
+		uart_remove_one_port(&sport_uart_reg, &sport->port);
+		iounmap(sport->port.membase);
+		peripheral_free_list(dev_get_platdata(&pdev->dev));
+		kfree(sport);
+		bfin_sport_uart_ports[pdev->id] = NULL;
+	}
+
+	return 0;
+}
+
+static struct platform_driver sport_uart_driver = {
+	.probe		= sport_uart_probe,
+	.remove		= sport_uart_remove,
+	.driver		= {
+		.name	= DRV_NAME,
+#ifdef CONFIG_PM
+		.pm	= &bfin_sport_uart_dev_pm_ops,
+#endif
+	},
+};
+
+#ifdef CONFIG_SERIAL_BFIN_SPORT_CONSOLE
+static struct early_platform_driver early_sport_uart_driver __initdata = {
+	.class_str = CLASS_BFIN_SPORT_CONSOLE,
+	.pdrv = &sport_uart_driver,
+	.requested_id = EARLY_PLATFORM_ID_UNSET,
+};
+
+static int __init sport_uart_rs_console_init(void)
+{
+	early_platform_driver_register(&early_sport_uart_driver, DRV_NAME);
+
+	early_platform_driver_probe(CLASS_BFIN_SPORT_CONSOLE,
+		BFIN_SPORT_UART_MAX_PORTS, 0);
+
+	register_console(&sport_uart_console);
+
+	return 0;
+}
+console_initcall(sport_uart_rs_console_init);
+#endif
+
+static int __init sport_uart_init(void)
+{
+	int ret;
+
+	pr_info("Blackfin uart over sport driver\n");
+
+	ret = uart_register_driver(&sport_uart_reg);
+	if (ret) {
+		pr_err("failed to register %s:%d\n",
+				sport_uart_reg.driver_name, ret);
+		return ret;
+	}
+
+	ret = platform_driver_register(&sport_uart_driver);
+	if (ret) {
+		pr_err("failed to register sport uart driver:%d\n", ret);
+		uart_unregister_driver(&sport_uart_reg);
+	}
+
+	return ret;
+}
+module_init(sport_uart_init);
+
+static void __exit sport_uart_exit(void)
+{
+	platform_driver_unregister(&sport_uart_driver);
+	uart_unregister_driver(&sport_uart_reg);
+}
+module_exit(sport_uart_exit);
+
+MODULE_AUTHOR("Sonic Zhang, Roy Huang");
+MODULE_DESCRIPTION("Blackfin serial over SPORT driver");
+MODULE_LICENSE("GPL");