MIPS: BCM63xx: Add serial driver for bcm63xx integrated UART.

Signed-off-by: Maxime Bizon <mbizon@freebox.fr>
Acked-by: Greg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

1 files changed, 890 insertions, 0 deletions

diff --git a/drivers/serial/bcm63xx_uart.c b/drivers/serial/bcm63xx_uart.c
new file mode 100644
index 00000000000..beddaa6e906
--- /dev/null
+++ b/drivers/serial/bcm63xx_uart.c
@@ -0,0 +1,890 @@
+/*
+ * This file is subject to the terms and conditions of the GNU General Public
+ * License.  See the file "COPYING" in the main directory of this archive
+ * for more details.
+ *
+ * Derived from many drivers using generic_serial interface.
+ *
+ * Copyright (C) 2008 Maxime Bizon <mbizon@freebox.fr>
+ *
+ *  Serial driver for BCM63xx integrated UART.
+ *
+ * Hardware flow control was _not_ tested since I only have RX/TX on
+ * my board.
+ */
+
+#if defined(CONFIG_SERIAL_BCM63XX_CONSOLE) && defined(CONFIG_MAGIC_SYSRQ)
+#define SUPPORT_SYSRQ
+#endif
+
+#include <linux/kernel.h>
+#include <linux/platform_device.h>
+#include <linux/init.h>
+#include <linux/delay.h>
+#include <linux/module.h>
+#include <linux/console.h>
+#include <linux/clk.h>
+#include <linux/tty.h>
+#include <linux/tty_flip.h>
+#include <linux/sysrq.h>
+#include <linux/serial.h>
+#include <linux/serial_core.h>
+
+#include <bcm63xx_clk.h>
+#include <bcm63xx_irq.h>
+#include <bcm63xx_regs.h>
+#include <bcm63xx_io.h>
+
+#define BCM63XX_NR_UARTS	1
+
+static struct uart_port ports[BCM63XX_NR_UARTS];
+
+/*
+ * rx interrupt mask / stat
+ *
+ * mask:
+ *  - rx fifo full
+ *  - rx fifo above threshold
+ *  - rx fifo not empty for too long
+ */
+#define UART_RX_INT_MASK	(UART_IR_MASK(UART_IR_RXOVER) |		\
+				UART_IR_MASK(UART_IR_RXTHRESH) |	\
+				UART_IR_MASK(UART_IR_RXTIMEOUT))
+
+#define UART_RX_INT_STAT	(UART_IR_STAT(UART_IR_RXOVER) |		\
+				UART_IR_STAT(UART_IR_RXTHRESH) |	\
+				UART_IR_STAT(UART_IR_RXTIMEOUT))
+
+/*
+ * tx interrupt mask / stat
+ *
+ * mask:
+ * - tx fifo empty
+ * - tx fifo below threshold
+ */
+#define UART_TX_INT_MASK	(UART_IR_MASK(UART_IR_TXEMPTY) |	\
+				UART_IR_MASK(UART_IR_TXTRESH))
+
+#define UART_TX_INT_STAT	(UART_IR_STAT(UART_IR_TXEMPTY) |	\
+				UART_IR_STAT(UART_IR_TXTRESH))
+
+/*
+ * external input interrupt
+ *
+ * mask: any edge on CTS, DCD
+ */
+#define UART_EXTINP_INT_MASK	(UART_EXTINP_IRMASK(UART_EXTINP_IR_CTS) | \
+				 UART_EXTINP_IRMASK(UART_EXTINP_IR_DCD))
+
+/*
+ * handy uart register accessor
+ */
+static inline unsigned int bcm_uart_readl(struct uart_port *port,
+					 unsigned int offset)
+{
+	return bcm_readl(port->membase + offset);
+}
+
+static inline void bcm_uart_writel(struct uart_port *port,
+				  unsigned int value, unsigned int offset)
+{
+	bcm_writel(value, port->membase + offset);
+}
+
+/*
+ * serial core request to check if uart tx fifo is empty
+ */
+static unsigned int bcm_uart_tx_empty(struct uart_port *port)
+{
+	unsigned int val;
+
+	val = bcm_uart_readl(port, UART_IR_REG);
+	return (val & UART_IR_STAT(UART_IR_TXEMPTY)) ? 1 : 0;
+}
+
+/*
+ * serial core request to set RTS and DTR pin state and loopback mode
+ */
+static void bcm_uart_set_mctrl(struct uart_port *port, unsigned int mctrl)
+{
+	unsigned int val;
+
+	val = bcm_uart_readl(port, UART_MCTL_REG);
+	val &= ~(UART_MCTL_DTR_MASK | UART_MCTL_RTS_MASK);
+	/* invert of written value is reflected on the pin */
+	if (!(mctrl & TIOCM_DTR))
+		val |= UART_MCTL_DTR_MASK;
+	if (!(mctrl & TIOCM_RTS))
+		val |= UART_MCTL_RTS_MASK;
+	bcm_uart_writel(port, val, UART_MCTL_REG);
+
+	val = bcm_uart_readl(port, UART_CTL_REG);
+	if (mctrl & TIOCM_LOOP)
+		val |= UART_CTL_LOOPBACK_MASK;
+	else
+		val &= ~UART_CTL_LOOPBACK_MASK;
+	bcm_uart_writel(port, val, UART_CTL_REG);
+}
+
+/*
+ * serial core request to return RI, CTS, DCD and DSR pin state
+ */
+static unsigned int bcm_uart_get_mctrl(struct uart_port *port)
+{
+	unsigned int val, mctrl;
+
+	mctrl = 0;
+	val = bcm_uart_readl(port, UART_EXTINP_REG);
+	if (val & UART_EXTINP_RI_MASK)
+		mctrl |= TIOCM_RI;
+	if (val & UART_EXTINP_CTS_MASK)
+		mctrl |= TIOCM_CTS;
+	if (val & UART_EXTINP_DCD_MASK)
+		mctrl |= TIOCM_CD;
+	if (val & UART_EXTINP_DSR_MASK)
+		mctrl |= TIOCM_DSR;
+	return mctrl;
+}
+
+/*
+ * serial core request to disable tx ASAP (used for flow control)
+ */
+static void bcm_uart_stop_tx(struct uart_port *port)
+{
+	unsigned int val;
+
+	val = bcm_uart_readl(port, UART_CTL_REG);
+	val &= ~(UART_CTL_TXEN_MASK);
+	bcm_uart_writel(port, val, UART_CTL_REG);
+
+	val = bcm_uart_readl(port, UART_IR_REG);
+	val &= ~UART_TX_INT_MASK;
+	bcm_uart_writel(port, val, UART_IR_REG);
+}
+
+/*
+ * serial core request to (re)enable tx
+ */
+static void bcm_uart_start_tx(struct uart_port *port)
+{
+	unsigned int val;
+
+	val = bcm_uart_readl(port, UART_IR_REG);
+	val |= UART_TX_INT_MASK;
+	bcm_uart_writel(port, val, UART_IR_REG);
+
+	val = bcm_uart_readl(port, UART_CTL_REG);
+	val |= UART_CTL_TXEN_MASK;
+	bcm_uart_writel(port, val, UART_CTL_REG);
+}
+
+/*
+ * serial core request to stop rx, called before port shutdown
+ */
+static void bcm_uart_stop_rx(struct uart_port *port)
+{
+	unsigned int val;
+
+	val = bcm_uart_readl(port, UART_IR_REG);
+	val &= ~UART_RX_INT_MASK;
+	bcm_uart_writel(port, val, UART_IR_REG);
+}
+
+/*
+ * serial core request to enable modem status interrupt reporting
+ */
+static void bcm_uart_enable_ms(struct uart_port *port)
+{
+	unsigned int val;
+
+	val = bcm_uart_readl(port, UART_IR_REG);
+	val |= UART_IR_MASK(UART_IR_EXTIP);
+	bcm_uart_writel(port, val, UART_IR_REG);
+}
+
+/*
+ * serial core request to start/stop emitting break char
+ */
+static void bcm_uart_break_ctl(struct uart_port *port, int ctl)
+{
+	unsigned long flags;
+	unsigned int val;
+
+	spin_lock_irqsave(&port->lock, flags);
+
+	val = bcm_uart_readl(port, UART_CTL_REG);
+	if (ctl)
+		val |= UART_CTL_XMITBRK_MASK;
+	else
+		val &= ~UART_CTL_XMITBRK_MASK;
+	bcm_uart_writel(port, val, UART_CTL_REG);
+
+	spin_unlock_irqrestore(&port->lock, flags);
+}
+
+/*
+ * return port type in string format
+ */
+static const char *bcm_uart_type(struct uart_port *port)
+{
+	return (port->type == PORT_BCM63XX) ? "bcm63xx_uart" : NULL;
+}
+
+/*
+ * read all chars in rx fifo and send them to core
+ */
+static void bcm_uart_do_rx(struct uart_port *port)
+{
+	struct tty_struct *tty;
+	unsigned int max_count;
+
+	/* limit number of char read in interrupt, should not be
+	 * higher than fifo size anyway since we're much faster than
+	 * serial port */
+	max_count = 32;
+	tty = port->info->port.tty;
+	do {
+		unsigned int iestat, c, cstat;
+		char flag;
+
+		/* get overrun/fifo empty information from ier
+		 * register */
+		iestat = bcm_uart_readl(port, UART_IR_REG);
+		if (!(iestat & UART_IR_STAT(UART_IR_RXNOTEMPTY)))
+			break;
+
+		cstat = c = bcm_uart_readl(port, UART_FIFO_REG);
+		port->icount.rx++;
+		flag = TTY_NORMAL;
+		c &= 0xff;
+
+		if (unlikely((cstat & UART_FIFO_ANYERR_MASK))) {
+			/* do stats first */
+			if (cstat & UART_FIFO_BRKDET_MASK) {
+				port->icount.brk++;
+				if (uart_handle_break(port))
+					continue;
+			}
+
+			if (cstat & UART_FIFO_PARERR_MASK)
+				port->icount.parity++;
+			if (cstat & UART_FIFO_FRAMEERR_MASK)
+				port->icount.frame++;
+
+			/* update flag wrt read_status_mask */
+			cstat &= port->read_status_mask;
+			if (cstat & UART_FIFO_BRKDET_MASK)
+				flag = TTY_BREAK;
+			if (cstat & UART_FIFO_FRAMEERR_MASK)
+				flag = TTY_FRAME;
+			if (cstat & UART_FIFO_PARERR_MASK)
+				flag = TTY_PARITY;
+		}
+
+		if (uart_handle_sysrq_char(port, c))
+			continue;
+
+		if (unlikely(iestat & UART_IR_STAT(UART_IR_RXOVER))) {
+			port->icount.overrun++;
+			tty_insert_flip_char(tty, 0, TTY_OVERRUN);
+		}
+
+		if ((cstat & port->ignore_status_mask) == 0)
+			tty_insert_flip_char(tty, c, flag);
+
+	} while (--max_count);
+
+	tty_flip_buffer_push(tty);
+}
+
+/*
+ * fill tx fifo with chars to send, stop when fifo is about to be full
+ * or when all chars have been sent.
+ */
+static void bcm_uart_do_tx(struct uart_port *port)
+{
+	struct circ_buf *xmit;
+	unsigned int val, max_count;
+
+	if (port->x_char) {
+		bcm_uart_writel(port, port->x_char, UART_FIFO_REG);
+		port->icount.tx++;
+		port->x_char = 0;
+		return;
+	}
+
+	if (uart_tx_stopped(port)) {
+		bcm_uart_stop_tx(port);
+		return;
+	}
+
+	xmit = &port->info->xmit;
+	if (uart_circ_empty(xmit))
+		goto txq_empty;
+
+	val = bcm_uart_readl(port, UART_MCTL_REG);
+	val = (val & UART_MCTL_TXFIFOFILL_MASK) >> UART_MCTL_TXFIFOFILL_SHIFT;
+	max_count = port->fifosize - val;
+
+	while (max_count--) {
+		unsigned int c;
+
+		c = xmit->buf[xmit->tail];
+		bcm_uart_writel(port, c, UART_FIFO_REG);
+		xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
+		port->icount.tx++;
+		if (uart_circ_empty(xmit))
+			break;
+	}
+
+	if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
+		uart_write_wakeup(port);
+
+	if (uart_circ_empty(xmit))
+		goto txq_empty;
+	return;
+
+txq_empty:
+	/* nothing to send, disable transmit interrupt */
+	val = bcm_uart_readl(port, UART_IR_REG);
+	val &= ~UART_TX_INT_MASK;
+	bcm_uart_writel(port, val, UART_IR_REG);
+	return;
+}
+
+/*
+ * process uart interrupt
+ */
+static irqreturn_t bcm_uart_interrupt(int irq, void *dev_id)
+{
+	struct uart_port *port;
+	unsigned int irqstat;
+
+	port = dev_id;
+	spin_lock(&port->lock);
+
+	irqstat = bcm_uart_readl(port, UART_IR_REG);
+	if (irqstat & UART_RX_INT_STAT)
+		bcm_uart_do_rx(port);
+
+	if (irqstat & UART_TX_INT_STAT)
+		bcm_uart_do_tx(port);
+
+	if (irqstat & UART_IR_MASK(UART_IR_EXTIP)) {
+		unsigned int estat;
+
+		estat = bcm_uart_readl(port, UART_EXTINP_REG);
+		if (estat & UART_EXTINP_IRSTAT(UART_EXTINP_IR_CTS))
+			uart_handle_cts_change(port,
+					       estat & UART_EXTINP_CTS_MASK);
+		if (estat & UART_EXTINP_IRSTAT(UART_EXTINP_IR_DCD))
+			uart_handle_dcd_change(port,
+					       estat & UART_EXTINP_DCD_MASK);
+	}
+
+	spin_unlock(&port->lock);
+	return IRQ_HANDLED;
+}
+
+/*
+ * enable rx & tx operation on uart
+ */
+static void bcm_uart_enable(struct uart_port *port)
+{
+	unsigned int val;
+
+	val = bcm_uart_readl(port, UART_CTL_REG);
+	val |= (UART_CTL_BRGEN_MASK | UART_CTL_TXEN_MASK | UART_CTL_RXEN_MASK);
+	bcm_uart_writel(port, val, UART_CTL_REG);
+}
+
+/*
+ * disable rx & tx operation on uart
+ */
+static void bcm_uart_disable(struct uart_port *port)
+{
+	unsigned int val;
+
+	val = bcm_uart_readl(port, UART_CTL_REG);
+	val &= ~(UART_CTL_BRGEN_MASK | UART_CTL_TXEN_MASK |
+		 UART_CTL_RXEN_MASK);
+	bcm_uart_writel(port, val, UART_CTL_REG);
+}
+
+/*
+ * clear all unread data in rx fifo and unsent data in tx fifo
+ */
+static void bcm_uart_flush(struct uart_port *port)
+{
+	unsigned int val;
+
+	/* empty rx and tx fifo */
+	val = bcm_uart_readl(port, UART_CTL_REG);
+	val |= UART_CTL_RSTRXFIFO_MASK | UART_CTL_RSTTXFIFO_MASK;
+	bcm_uart_writel(port, val, UART_CTL_REG);
+
+	/* read any pending char to make sure all irq status are
+	 * cleared */
+	(void)bcm_uart_readl(port, UART_FIFO_REG);
+}
+
+/*
+ * serial core request to initialize uart and start rx operation
+ */
+static int bcm_uart_startup(struct uart_port *port)
+{
+	unsigned int val;
+	int ret;
+
+	/* mask all irq and flush port */
+	bcm_uart_disable(port);
+	bcm_uart_writel(port, 0, UART_IR_REG);
+	bcm_uart_flush(port);
+
+	/* clear any pending external input interrupt */
+	(void)bcm_uart_readl(port, UART_EXTINP_REG);
+
+	/* set rx/tx fifo thresh to fifo half size */
+	val = bcm_uart_readl(port, UART_MCTL_REG);
+	val &= ~(UART_MCTL_RXFIFOTHRESH_MASK | UART_MCTL_TXFIFOTHRESH_MASK);
+	val |= (port->fifosize / 2) << UART_MCTL_RXFIFOTHRESH_SHIFT;
+	val |= (port->fifosize / 2) << UART_MCTL_TXFIFOTHRESH_SHIFT;
+	bcm_uart_writel(port, val, UART_MCTL_REG);
+
+	/* set rx fifo timeout to 1 char time */
+	val = bcm_uart_readl(port, UART_CTL_REG);
+	val &= ~UART_CTL_RXTMOUTCNT_MASK;
+	val |= 1 << UART_CTL_RXTMOUTCNT_SHIFT;
+	bcm_uart_writel(port, val, UART_CTL_REG);
+
+	/* report any edge on dcd and cts */
+	val = UART_EXTINP_INT_MASK;
+	val |= UART_EXTINP_DCD_NOSENSE_MASK;
+	val |= UART_EXTINP_CTS_NOSENSE_MASK;
+	bcm_uart_writel(port, val, UART_EXTINP_REG);
+
+	/* register irq and enable rx interrupts */
+	ret = request_irq(port->irq, bcm_uart_interrupt, 0,
+			  bcm_uart_type(port), port);
+	if (ret)
+		return ret;
+	bcm_uart_writel(port, UART_RX_INT_MASK, UART_IR_REG);
+	bcm_uart_enable(port);
+	return 0;
+}
+
+/*
+ * serial core request to flush & disable uart
+ */
+static void bcm_uart_shutdown(struct uart_port *port)
+{
+	unsigned long flags;
+
+	spin_lock_irqsave(&port->lock, flags);
+	bcm_uart_writel(port, 0, UART_IR_REG);
+	spin_unlock_irqrestore(&port->lock, flags);
+
+	bcm_uart_disable(port);
+	bcm_uart_flush(port);
+	free_irq(port->irq, port);
+}
+
+/*
+ * serial core request to change current uart setting
+ */
+static void bcm_uart_set_termios(struct uart_port *port,
+				 struct ktermios *new,
+				 struct ktermios *old)
+{
+	unsigned int ctl, baud, quot, ier;
+	unsigned long flags;
+
+	spin_lock_irqsave(&port->lock, flags);
+
+	/* disable uart while changing speed */
+	bcm_uart_disable(port);
+	bcm_uart_flush(port);
+
+	/* update Control register */
+	ctl = bcm_uart_readl(port, UART_CTL_REG);
+	ctl &= ~UART_CTL_BITSPERSYM_MASK;
+
+	switch (new->c_cflag & CSIZE) {
+	case CS5:
+		ctl |= (0 << UART_CTL_BITSPERSYM_SHIFT);
+		break;
+	case CS6:
+		ctl |= (1 << UART_CTL_BITSPERSYM_SHIFT);
+		break;
+	case CS7:
+		ctl |= (2 << UART_CTL_BITSPERSYM_SHIFT);
+		break;
+	default:
+		ctl |= (3 << UART_CTL_BITSPERSYM_SHIFT);
+		break;
+	}
+
+	ctl &= ~UART_CTL_STOPBITS_MASK;
+	if (new->c_cflag & CSTOPB)
+		ctl |= UART_CTL_STOPBITS_2;
+	else
+		ctl |= UART_CTL_STOPBITS_1;
+
+	ctl &= ~(UART_CTL_RXPAREN_MASK | UART_CTL_TXPAREN_MASK);
+	if (new->c_cflag & PARENB)
+		ctl |= (UART_CTL_RXPAREN_MASK | UART_CTL_TXPAREN_MASK);
+	ctl &= ~(UART_CTL_RXPAREVEN_MASK | UART_CTL_TXPAREVEN_MASK);
+	if (new->c_cflag & PARODD)
+		ctl |= (UART_CTL_RXPAREVEN_MASK | UART_CTL_TXPAREVEN_MASK);
+	bcm_uart_writel(port, ctl, UART_CTL_REG);
+
+	/* update Baudword register */
+	baud = uart_get_baud_rate(port, new, old, 0, port->uartclk / 16);
+	quot = uart_get_divisor(port, baud) - 1;
+	bcm_uart_writel(port, quot, UART_BAUD_REG);
+
+	/* update Interrupt register */
+	ier = bcm_uart_readl(port, UART_IR_REG);
+
+	ier &= ~UART_IR_MASK(UART_IR_EXTIP);
+	if (UART_ENABLE_MS(port, new->c_cflag))
+		ier |= UART_IR_MASK(UART_IR_EXTIP);
+
+	bcm_uart_writel(port, ier, UART_IR_REG);
+
+	/* update read/ignore mask */
+	port->read_status_mask = UART_FIFO_VALID_MASK;
+	if (new->c_iflag & INPCK) {
+		port->read_status_mask |= UART_FIFO_FRAMEERR_MASK;
+		port->read_status_mask |= UART_FIFO_PARERR_MASK;
+	}
+	if (new->c_iflag & (BRKINT))
+		port->read_status_mask |= UART_FIFO_BRKDET_MASK;
+
+	port->ignore_status_mask = 0;
+	if (new->c_iflag & IGNPAR)
+		port->ignore_status_mask |= UART_FIFO_PARERR_MASK;
+	if (new->c_iflag & IGNBRK)
+		port->ignore_status_mask |= UART_FIFO_BRKDET_MASK;
+	if (!(new->c_cflag & CREAD))
+		port->ignore_status_mask |= UART_FIFO_VALID_MASK;
+
+	uart_update_timeout(port, new->c_cflag, baud);
+	bcm_uart_enable(port);
+	spin_unlock_irqrestore(&port->lock, flags);
+}
+
+/*
+ * serial core request to claim uart iomem
+ */
+static int bcm_uart_request_port(struct uart_port *port)
+{
+	unsigned int size;
+
+	size = RSET_UART_SIZE;
+	if (!request_mem_region(port->mapbase, size, "bcm63xx")) {
+		dev_err(port->dev, "Memory region busy\n");
+		return -EBUSY;
+	}
+
+	port->membase = ioremap(port->mapbase, size);
+	if (!port->membase) {
+		dev_err(port->dev, "Unable to map registers\n");
+		release_mem_region(port->mapbase, size);
+		return -EBUSY;
+	}
+	return 0;
+}
+
+/*
+ * serial core request to release uart iomem
+ */
+static void bcm_uart_release_port(struct uart_port *port)
+{
+	release_mem_region(port->mapbase, RSET_UART_SIZE);
+	iounmap(port->membase);
+}
+
+/*
+ * serial core request to do any port required autoconfiguration
+ */
+static void bcm_uart_config_port(struct uart_port *port, int flags)
+{
+	if (flags & UART_CONFIG_TYPE) {
+		if (bcm_uart_request_port(port))
+			return;
+		port->type = PORT_BCM63XX;
+	}
+}
+
+/*
+ * serial core request to check that port information in serinfo are
+ * suitable
+ */
+static int bcm_uart_verify_port(struct uart_port *port,
+				struct serial_struct *serinfo)
+{
+	if (port->type != PORT_BCM63XX)
+		return -EINVAL;
+	if (port->irq != serinfo->irq)
+		return -EINVAL;
+	if (port->iotype != serinfo->io_type)
+		return -EINVAL;
+	if (port->mapbase != (unsigned long)serinfo->iomem_base)
+		return -EINVAL;
+	return 0;
+}
+
+/* serial core callbacks */
+static struct uart_ops bcm_uart_ops = {
+	.tx_empty	= bcm_uart_tx_empty,
+	.get_mctrl	= bcm_uart_get_mctrl,
+	.set_mctrl	= bcm_uart_set_mctrl,
+	.start_tx	= bcm_uart_start_tx,
+	.stop_tx	= bcm_uart_stop_tx,
+	.stop_rx	= bcm_uart_stop_rx,
+	.enable_ms	= bcm_uart_enable_ms,
+	.break_ctl	= bcm_uart_break_ctl,
+	.startup	= bcm_uart_startup,
+	.shutdown	= bcm_uart_shutdown,
+	.set_termios	= bcm_uart_set_termios,
+	.type		= bcm_uart_type,
+	.release_port	= bcm_uart_release_port,
+	.request_port	= bcm_uart_request_port,
+	.config_port	= bcm_uart_config_port,
+	.verify_port	= bcm_uart_verify_port,
+};
+
+
+
+#ifdef CONFIG_SERIAL_BCM63XX_CONSOLE
+static inline void wait_for_xmitr(struct uart_port *port)
+{
+	unsigned int tmout;
+
+	/* Wait up to 10ms for the character(s) to be sent. */
+	tmout = 10000;
+	while (--tmout) {
+		unsigned int val;
+
+		val = bcm_uart_readl(port, UART_IR_REG);
+		if (val & UART_IR_STAT(UART_IR_TXEMPTY))
+			break;
+		udelay(1);
+	}
+
+	/* Wait up to 1s for flow control if necessary */
+	if (port->flags & UPF_CONS_FLOW) {
+		tmout = 1000000;
+		while (--tmout) {
+			unsigned int val;
+
+			val = bcm_uart_readl(port, UART_EXTINP_REG);
+			if (val & UART_EXTINP_CTS_MASK)
+				break;
+			udelay(1);
+		}
+	}
+}
+
+/*
+ * output given char
+ */
+static void bcm_console_putchar(struct uart_port *port, int ch)
+{
+	wait_for_xmitr(port);
+	bcm_uart_writel(port, ch, UART_FIFO_REG);
+}
+
+/*
+ * console core request to output given string
+ */
+static void bcm_console_write(struct console *co, const char *s,
+			      unsigned int count)
+{
+	struct uart_port *port;
+	unsigned long flags;
+	int locked;
+
+	port = &ports[co->index];
+
+	local_irq_save(flags);
+	if (port->sysrq) {
+		/* bcm_uart_interrupt() already took the lock */
+		locked = 0;
+	} else if (oops_in_progress) {
+		locked = spin_trylock(&port->lock);
+	} else {
+		spin_lock(&port->lock);
+		locked = 1;
+	}
+
+	/* call helper to deal with \r\n */
+	uart_console_write(port, s, count, bcm_console_putchar);
+
+	/* and wait for char to be transmitted */
+	wait_for_xmitr(port);
+
+	if (locked)
+		spin_unlock(&port->lock);
+	local_irq_restore(flags);
+}
+
+/*
+ * console core request to setup given console, find matching uart
+ * port and setup it.
+ */
+static int bcm_console_setup(struct console *co, char *options)
+{
+	struct uart_port *port;
+	int baud = 9600;
+	int bits = 8;
+	int parity = 'n';
+	int flow = 'n';
+
+	if (co->index < 0 || co->index >= BCM63XX_NR_UARTS)
+		return -EINVAL;
+	port = &ports[co->index];
+	if (!port->membase)
+		return -ENODEV;
+	if (options)
+		uart_parse_options(options, &baud, &parity, &bits, &flow);
+
+	return uart_set_options(port, co, baud, parity, bits, flow);
+}
+
+static struct uart_driver bcm_uart_driver;
+
+static struct console bcm63xx_console = {
+	.name		= "ttyS",
+	.write		= bcm_console_write,
+	.device		= uart_console_device,
+	.setup		= bcm_console_setup,
+	.flags		= CON_PRINTBUFFER,
+	.index		= -1,
+	.data		= &bcm_uart_driver,
+};
+
+static int __init bcm63xx_console_init(void)
+{
+	register_console(&bcm63xx_console);
+	return 0;
+}
+
+console_initcall(bcm63xx_console_init);
+
+#define BCM63XX_CONSOLE	(&bcm63xx_console)
+#else
+#define BCM63XX_CONSOLE	NULL
+#endif /* CONFIG_SERIAL_BCM63XX_CONSOLE */
+
+static struct uart_driver bcm_uart_driver = {
+	.owner		= THIS_MODULE,
+	.driver_name	= "bcm63xx_uart",
+	.dev_name	= "ttyS",
+	.major		= TTY_MAJOR,
+	.minor		= 64,
+	.nr		= 1,
+	.cons		= BCM63XX_CONSOLE,
+};
+
+/*
+ * platform driver probe/remove callback
+ */
+static int __devinit bcm_uart_probe(struct platform_device *pdev)
+{
+	struct resource *res_mem, *res_irq;
+	struct uart_port *port;
+	struct clk *clk;
+	int ret;
+
+	if (pdev->id < 0 || pdev->id >= BCM63XX_NR_UARTS)
+		return -EINVAL;
+
+	if (ports[pdev->id].membase)
+		return -EBUSY;
+
+	res_mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	if (!res_mem)
+		return -ENODEV;
+
+	res_irq = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
+	if (!res_irq)
+		return -ENODEV;
+
+	clk = clk_get(&pdev->dev, "periph");
+	if (IS_ERR(clk))
+		return -ENODEV;
+
+	port = &ports[pdev->id];
+	memset(port, 0, sizeof(*port));
+	port->iotype = UPIO_MEM;
+	port->mapbase = res_mem->start;
+	port->irq = res_irq->start;
+	port->ops = &bcm_uart_ops;
+	port->flags = UPF_BOOT_AUTOCONF;
+	port->dev = &pdev->dev;
+	port->fifosize = 16;
+	port->uartclk = clk_get_rate(clk) / 2;
+	clk_put(clk);
+
+	ret = uart_add_one_port(&bcm_uart_driver, port);
+	if (ret) {
+		kfree(port);
+		return ret;
+	}
+	platform_set_drvdata(pdev, port);
+	return 0;
+}
+
+static int __devexit bcm_uart_remove(struct platform_device *pdev)
+{
+	struct uart_port *port;
+
+	port = platform_get_drvdata(pdev);
+	uart_remove_one_port(&bcm_uart_driver, port);
+	platform_set_drvdata(pdev, NULL);
+	/* mark port as free */
+	ports[pdev->id].membase = 0;
+	return 0;
+}
+
+/*
+ * platform driver stuff
+ */
+static struct platform_driver bcm_uart_platform_driver = {
+	.probe	= bcm_uart_probe,
+	.remove	= __devexit_p(bcm_uart_remove),
+	.driver	= {
+		.owner = THIS_MODULE,
+		.name  = "bcm63xx_uart",
+	},
+};
+
+static int __init bcm_uart_init(void)
+{
+	int ret;
+
+	ret = uart_register_driver(&bcm_uart_driver);
+	if (ret)
+		return ret;
+
+	ret = platform_driver_register(&bcm_uart_platform_driver);
+	if (ret)
+		uart_unregister_driver(&bcm_uart_driver);
+
+	return ret;
+}
+
+static void __exit bcm_uart_exit(void)
+{
+	platform_driver_unregister(&bcm_uart_platform_driver);
+	uart_unregister_driver(&bcm_uart_driver);
+}
+
+module_init(bcm_uart_init);
+module_exit(bcm_uart_exit);
+
+MODULE_AUTHOR("Maxime Bizon <mbizon@freebox.fr>");
+MODULE_DESCRIPTION("Broadcom 63<xx integrated uart driver");
+MODULE_LICENSE("GPL");