drivers/tty/serial/amba-pl010.c - kernel/msm-4.19 - Gitiles

 /*
  *  Driver for AMBA serial ports
  *
  *  Based on drivers/char/serial.c, by Linus Torvalds, Theodore Ts'o.
  *
  *  Copyright 1999 ARM Limited
  *  Copyright (C) 2000 Deep Blue Solutions Ltd.
  *
  * 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, write to the Free Software
  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  *
  * This is a generic driver for ARM AMBA-type serial ports.  They
  * have a lot of 16550-like features, but are not register compatible.
  * Note that although they do have CTS, DCD and DSR inputs, they do
  * not have an RI input, nor do they have DTR or RTS outputs.  If
  * required, these have to be supplied via some other means (eg, GPIO)
  * and hooked into this driver.
  */

 #if defined(CONFIG_SERIAL_AMBA_PL010_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/device.h>
 #include <linux/tty.h>
 #include <linux/tty_flip.h>
 #include <linux/serial_core.h>
 #include <linux/serial.h>
 #include <linux/amba/bus.h>
 #include <linux/amba/serial.h>
 #include <linux/clk.h>
 #include <linux/slab.h>
 #include <linux/io.h>

 #define UART_NR		8

 #define SERIAL_AMBA_MAJOR	204
 #define SERIAL_AMBA_MINOR	16
 #define SERIAL_AMBA_NR		UART_NR

 #define AMBA_ISR_PASS_LIMIT	256

 #define UART_RX_DATA(s)		(((s) & UART01x_FR_RXFE) == 0)
 #define UART_TX_READY(s)	(((s) & UART01x_FR_TXFF) == 0)

 #define UART_DUMMY_RSR_RX	256
 #define UART_PORT_SIZE		64

 /*
  * We wrap our port structure around the generic uart_port.
  */
 struct uart_amba_port {
 	struct uart_port	port;
 	struct clk		*clk;
 	struct amba_device	*dev;
 	struct amba_pl010_data	*data;
 	unsigned int		old_status;
 };

 static void pl010_stop_tx(struct uart_port *port)
 {
 	struct uart_amba_port *uap =
 		container_of(port, struct uart_amba_port, port);
 	unsigned int cr;

 	cr = readb(uap->port.membase + UART010_CR);
 	cr &= ~UART010_CR_TIE;
 	writel(cr, uap->port.membase + UART010_CR);
 }

 static void pl010_start_tx(struct uart_port *port)
 {
 	struct uart_amba_port *uap =
 		container_of(port, struct uart_amba_port, port);
 	unsigned int cr;

 	cr = readb(uap->port.membase + UART010_CR);
 	cr |= UART010_CR_TIE;
 	writel(cr, uap->port.membase + UART010_CR);
 }

 static void pl010_stop_rx(struct uart_port *port)
 {
 	struct uart_amba_port *uap =
 		container_of(port, struct uart_amba_port, port);
 	unsigned int cr;

 	cr = readb(uap->port.membase + UART010_CR);
 	cr &= ~(UART010_CR_RIE | UART010_CR_RTIE);
 	writel(cr, uap->port.membase + UART010_CR);
 }

 static void pl010_disable_ms(struct uart_port *port)
 {
 	struct uart_amba_port *uap = (struct uart_amba_port *)port;
 	unsigned int cr;

 	cr = readb(uap->port.membase + UART010_CR);
 	cr &= ~UART010_CR_MSIE;
 	writel(cr, uap->port.membase + UART010_CR);
 }

 static void pl010_enable_ms(struct uart_port *port)
 {
 	struct uart_amba_port *uap =
 		container_of(port, struct uart_amba_port, port);
 	unsigned int cr;

 	cr = readb(uap->port.membase + UART010_CR);
 	cr |= UART010_CR_MSIE;
 	writel(cr, uap->port.membase + UART010_CR);
 }

 static void pl010_rx_chars(struct uart_amba_port *uap)
 {
 	unsigned int status, ch, flag, rsr, max_count = 256;

 	status = readb(uap->port.membase + UART01x_FR);
 	while (UART_RX_DATA(status) && max_count--) {
 		ch = readb(uap->port.membase + UART01x_DR);
 		flag = TTY_NORMAL;

 		uap->port.icount.rx++;

 		/*
 		 * Note that the error handling code is
 		 * out of the main execution path
 		 */
 		rsr = readb(uap->port.membase + UART01x_RSR) | UART_DUMMY_RSR_RX;
 		if (unlikely(rsr & UART01x_RSR_ANY)) {
 			writel(0, uap->port.membase + UART01x_ECR);

 			if (rsr & UART01x_RSR_BE) {
 				rsr &= ~(UART01x_RSR_FE | UART01x_RSR_PE);
 				uap->port.icount.brk++;
 				if (uart_handle_break(&uap->port))
 					goto ignore_char;
 			} else if (rsr & UART01x_RSR_PE)
 				uap->port.icount.parity++;
 			else if (rsr & UART01x_RSR_FE)
 				uap->port.icount.frame++;
 			if (rsr & UART01x_RSR_OE)
 				uap->port.icount.overrun++;

 			rsr &= uap->port.read_status_mask;

 			if (rsr & UART01x_RSR_BE)
 				flag = TTY_BREAK;
 			else if (rsr & UART01x_RSR_PE)
 				flag = TTY_PARITY;
 			else if (rsr & UART01x_RSR_FE)
 				flag = TTY_FRAME;
 		}

 		if (uart_handle_sysrq_char(&uap->port, ch))
 			goto ignore_char;

 		uart_insert_char(&uap->port, rsr, UART01x_RSR_OE, ch, flag);

 	ignore_char:
 		status = readb(uap->port.membase + UART01x_FR);
 	}
 	spin_unlock(&uap->port.lock);
 	tty_flip_buffer_push(&uap->port.state->port);
 	spin_lock(&uap->port.lock);
 }

 static void pl010_tx_chars(struct uart_amba_port *uap)
 {
 	struct circ_buf *xmit = &uap->port.state->xmit;
 	int count;

 	if (uap->port.x_char) {
 		writel(uap->port.x_char, uap->port.membase + UART01x_DR);
 		uap->port.icount.tx++;
 		uap->port.x_char = 0;
 		return;
 	}
 	if (uart_circ_empty(xmit) || uart_tx_stopped(&uap->port)) {
 		pl010_stop_tx(&uap->port);
 		return;
 	}

 	count = uap->port.fifosize >> 1;
 	do {
 		writel(xmit->buf[xmit->tail], uap->port.membase + UART01x_DR);
 		xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
 		uap->port.icount.tx++;
 		if (uart_circ_empty(xmit))
 			break;
 	} while (--count > 0);

 	if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
 		uart_write_wakeup(&uap->port);

 	if (uart_circ_empty(xmit))
 		pl010_stop_tx(&uap->port);
 }

 static void pl010_modem_status(struct uart_amba_port *uap)
 {
 	unsigned int status, delta;

 	writel(0, uap->port.membase + UART010_ICR);

 	status = readb(uap->port.membase + UART01x_FR) & UART01x_FR_MODEM_ANY;

 	delta = status ^ uap->old_status;
 	uap->old_status = status;

 	if (!delta)
 		return;

 	if (delta & UART01x_FR_DCD)
 		uart_handle_dcd_change(&uap->port, status & UART01x_FR_DCD);

 	if (delta & UART01x_FR_DSR)
 		uap->port.icount.dsr++;

 	if (delta & UART01x_FR_CTS)
 		uart_handle_cts_change(&uap->port, status & UART01x_FR_CTS);

 	wake_up_interruptible(&uap->port.state->port.delta_msr_wait);
 }

 static irqreturn_t pl010_int(int irq, void *dev_id)
 {
 	struct uart_amba_port *uap = dev_id;
 	unsigned int status, pass_counter = AMBA_ISR_PASS_LIMIT;
 	int handled = 0;

 	spin_lock(&uap->port.lock);

 	status = readb(uap->port.membase + UART010_IIR);
 	if (status) {
 		do {
 			if (status & (UART010_IIR_RTIS | UART010_IIR_RIS))
 				pl010_rx_chars(uap);
 			if (status & UART010_IIR_MIS)
 				pl010_modem_status(uap);
 			if (status & UART010_IIR_TIS)
 				pl010_tx_chars(uap);

 			if (pass_counter-- == 0)
 				break;

 			status = readb(uap->port.membase + UART010_IIR);
 		} while (status & (UART010_IIR_RTIS | UART010_IIR_RIS |
 				   UART010_IIR_TIS));
 		handled = 1;
 	}

 	spin_unlock(&uap->port.lock);

 	return IRQ_RETVAL(handled);
 }

 static unsigned int pl010_tx_empty(struct uart_port *port)
 {
 	struct uart_amba_port *uap =
 		container_of(port, struct uart_amba_port, port);
 	unsigned int status = readb(uap->port.membase + UART01x_FR);
 	return status & UART01x_FR_BUSY ? 0 : TIOCSER_TEMT;
 }

 static unsigned int pl010_get_mctrl(struct uart_port *port)
 {
 	struct uart_amba_port *uap =
 		container_of(port, struct uart_amba_port, port);
 	unsigned int result = 0;
 	unsigned int status;

 	status = readb(uap->port.membase + UART01x_FR);
 	if (status & UART01x_FR_DCD)
 		result |= TIOCM_CAR;
 	if (status & UART01x_FR_DSR)
 		result |= TIOCM_DSR;
 	if (status & UART01x_FR_CTS)
 		result |= TIOCM_CTS;

 	return result;
 }

 static void pl010_set_mctrl(struct uart_port *port, unsigned int mctrl)
 {
 	struct uart_amba_port *uap =
 		container_of(port, struct uart_amba_port, port);

 	if (uap->data)
 		uap->data->set_mctrl(uap->dev, uap->port.membase, mctrl);
 }

 static void pl010_break_ctl(struct uart_port *port, int break_state)
 {
 	struct uart_amba_port *uap =
 		container_of(port, struct uart_amba_port, port);
 	unsigned long flags;
 	unsigned int lcr_h;

 	spin_lock_irqsave(&uap->port.lock, flags);
 	lcr_h = readb(uap->port.membase + UART010_LCRH);
 	if (break_state == -1)
 		lcr_h |= UART01x_LCRH_BRK;
 	else
 		lcr_h &= ~UART01x_LCRH_BRK;
 	writel(lcr_h, uap->port.membase + UART010_LCRH);
 	spin_unlock_irqrestore(&uap->port.lock, flags);
 }

 static int pl010_startup(struct uart_port *port)
 {
 	struct uart_amba_port *uap =
 		container_of(port, struct uart_amba_port, port);
 	int retval;

 	/*
 	 * Try to enable the clock producer.
 	 */
 	retval = clk_prepare_enable(uap->clk);
 	if (retval)
 		goto out;

 	uap->port.uartclk = clk_get_rate(uap->clk);

 	/*
 	 * Allocate the IRQ
 	 */
 	retval = request_irq(uap->port.irq, pl010_int, 0, "uart-pl010", uap);
 	if (retval)
 		goto clk_dis;

 	/*
 	 * initialise the old status of the modem signals
 	 */
 	uap->old_status = readb(uap->port.membase + UART01x_FR) & UART01x_FR_MODEM_ANY;

 	/*
 	 * Finally, enable interrupts
 	 */
 	writel(UART01x_CR_UARTEN | UART010_CR_RIE | UART010_CR_RTIE,
 	       uap->port.membase + UART010_CR);

 	return 0;

  clk_dis:
 	clk_disable_unprepare(uap->clk);
  out:
 	return retval;
 }

 static void pl010_shutdown(struct uart_port *port)
 {
 	struct uart_amba_port *uap =
 		container_of(port, struct uart_amba_port, port);

 	/*
 	 * Free the interrupt
 	 */
 	free_irq(uap->port.irq, uap);

 	/*
 	 * disable all interrupts, disable the port
 	 */
 	writel(0, uap->port.membase + UART010_CR);

 	/* disable break condition and fifos */
 	writel(readb(uap->port.membase + UART010_LCRH) &
 		~(UART01x_LCRH_BRK | UART01x_LCRH_FEN),
 	       uap->port.membase + UART010_LCRH);

 	/*
 	 * Shut down the clock producer
 	 */
 	clk_disable_unprepare(uap->clk);
 }

 static void
 pl010_set_termios(struct uart_port *port, struct ktermios *termios,
 		     struct ktermios *old)
 {
 	struct uart_amba_port *uap =
 		container_of(port, struct uart_amba_port, port);
 	unsigned int lcr_h, old_cr;
 	unsigned long flags;
 	unsigned int baud, quot;

 	/*
 	 * Ask the core to calculate the divisor for us.
 	 */
 	baud = uart_get_baud_rate(port, termios, old, 0, uap->port.uartclk/16);
 	quot = uart_get_divisor(port, baud);

 	switch (termios->c_cflag & CSIZE) {
 	case CS5:
 		lcr_h = UART01x_LCRH_WLEN_5;
 		break;
 	case CS6:
 		lcr_h = UART01x_LCRH_WLEN_6;
 		break;
 	case CS7:
 		lcr_h = UART01x_LCRH_WLEN_7;
 		break;
 	default: // CS8
 		lcr_h = UART01x_LCRH_WLEN_8;
 		break;
 	}
 	if (termios->c_cflag & CSTOPB)
 		lcr_h |= UART01x_LCRH_STP2;
 	if (termios->c_cflag & PARENB) {
 		lcr_h |= UART01x_LCRH_PEN;
 		if (!(termios->c_cflag & PARODD))
 			lcr_h |= UART01x_LCRH_EPS;
 	}
 	if (uap->port.fifosize > 1)
 		lcr_h |= UART01x_LCRH_FEN;

 	spin_lock_irqsave(&uap->port.lock, flags);

 	/*
 	 * Update the per-port timeout.
 	 */
 	uart_update_timeout(port, termios->c_cflag, baud);

 	uap->port.read_status_mask = UART01x_RSR_OE;
 	if (termios->c_iflag & INPCK)
 		uap->port.read_status_mask |= UART01x_RSR_FE | UART01x_RSR_PE;
 	if (termios->c_iflag & (IGNBRK | BRKINT | PARMRK))
 		uap->port.read_status_mask |= UART01x_RSR_BE;

 	/*
 	 * Characters to ignore
 	 */
 	uap->port.ignore_status_mask = 0;
 	if (termios->c_iflag & IGNPAR)
 		uap->port.ignore_status_mask |= UART01x_RSR_FE | UART01x_RSR_PE;
 	if (termios->c_iflag & IGNBRK) {
 		uap->port.ignore_status_mask |= UART01x_RSR_BE;
 		/*
 		 * If we're ignoring parity and break indicators,
 		 * ignore overruns too (for real raw support).
 		 */
 		if (termios->c_iflag & IGNPAR)
 			uap->port.ignore_status_mask |= UART01x_RSR_OE;
 	}

 	/*
 	 * Ignore all characters if CREAD is not set.
 	 */
 	if ((termios->c_cflag & CREAD) == 0)
 		uap->port.ignore_status_mask |= UART_DUMMY_RSR_RX;

 	/* first, disable everything */
 	old_cr = readb(uap->port.membase + UART010_CR) & ~UART010_CR_MSIE;

 	if (UART_ENABLE_MS(port, termios->c_cflag))
 		old_cr |= UART010_CR_MSIE;

 	writel(0, uap->port.membase + UART010_CR);

 	/* Set baud rate */
 	quot -= 1;
 	writel((quot & 0xf00) >> 8, uap->port.membase + UART010_LCRM);
 	writel(quot & 0xff, uap->port.membase + UART010_LCRL);

 	/*
 	 * ----------v----------v----------v----------v-----
 	 * NOTE: MUST BE WRITTEN AFTER UARTLCR_M & UARTLCR_L
 	 * ----------^----------^----------^----------^-----
 	 */
 	writel(lcr_h, uap->port.membase + UART010_LCRH);
 	writel(old_cr, uap->port.membase + UART010_CR);

 	spin_unlock_irqrestore(&uap->port.lock, flags);
 }

 static void pl010_set_ldisc(struct uart_port *port, struct ktermios *termios)
 {
 	if (termios->c_line == N_PPS) {
 		port->flags |= UPF_HARDPPS_CD;
 		spin_lock_irq(&port->lock);
 		pl010_enable_ms(port);
 		spin_unlock_irq(&port->lock);
 	} else {
 		port->flags &= ~UPF_HARDPPS_CD;
 		if (!UART_ENABLE_MS(port, termios->c_cflag)) {
 			spin_lock_irq(&port->lock);
 			pl010_disable_ms(port);
 			spin_unlock_irq(&port->lock);
 		}
 	}
 }

 static const char *pl010_type(struct uart_port *port)
 {
 	return port->type == PORT_AMBA ? "AMBA" : NULL;
 }

 /*
  * Release the memory region(s) being used by 'port'
  */
 static void pl010_release_port(struct uart_port *port)
 {
 	release_mem_region(port->mapbase, UART_PORT_SIZE);
 }

 /*
  * Request the memory region(s) being used by 'port'
  */
 static int pl010_request_port(struct uart_port *port)
 {
 	return request_mem_region(port->mapbase, UART_PORT_SIZE, "uart-pl010")
 			!= NULL ? 0 : -EBUSY;
 }

 /*
  * Configure/autoconfigure the port.
  */
 static void pl010_config_port(struct uart_port *port, int flags)
 {
 	if (flags & UART_CONFIG_TYPE) {
 		port->type = PORT_AMBA;
 		pl010_request_port(port);
 	}
 }

 /*
  * verify the new serial_struct (for TIOCSSERIAL).
  */
 static int pl010_verify_port(struct uart_port *port, struct serial_struct *ser)
 {
 	int ret = 0;
 	if (ser->type != PORT_UNKNOWN && ser->type != PORT_AMBA)
 		ret = -EINVAL;
 	if (ser->irq < 0 || ser->irq >= nr_irqs)
 		ret = -EINVAL;
 	if (ser->baud_base < 9600)
 		ret = -EINVAL;
 	return ret;
 }

 static const struct uart_ops amba_pl010_pops = {
 	.tx_empty	= pl010_tx_empty,
 	.set_mctrl	= pl010_set_mctrl,
 	.get_mctrl	= pl010_get_mctrl,
 	.stop_tx	= pl010_stop_tx,
 	.start_tx	= pl010_start_tx,
 	.stop_rx	= pl010_stop_rx,
 	.enable_ms	= pl010_enable_ms,
 	.break_ctl	= pl010_break_ctl,
 	.startup	= pl010_startup,
 	.shutdown	= pl010_shutdown,
 	.set_termios	= pl010_set_termios,
 	.set_ldisc	= pl010_set_ldisc,
 	.type		= pl010_type,
 	.release_port	= pl010_release_port,
 	.request_port	= pl010_request_port,
 	.config_port	= pl010_config_port,
 	.verify_port	= pl010_verify_port,
 };

 static struct uart_amba_port *amba_ports[UART_NR];

 #ifdef CONFIG_SERIAL_AMBA_PL010_CONSOLE

 static void pl010_console_putchar(struct uart_port *port, int ch)
 {
 	struct uart_amba_port *uap =
 		container_of(port, struct uart_amba_port, port);
 	unsigned int status;

 	do {
 		status = readb(uap->port.membase + UART01x_FR);
 		barrier();
 	} while (!UART_TX_READY(status));
 	writel(ch, uap->port.membase + UART01x_DR);
 }

 static void
 pl010_console_write(struct console *co, const char *s, unsigned int count)
 {
 	struct uart_amba_port *uap = amba_ports[co->index];
 	unsigned int status, old_cr;

 	clk_enable(uap->clk);

 	/*
 	 *	First save the CR then disable the interrupts
 	 */
 	old_cr = readb(uap->port.membase + UART010_CR);
 	writel(UART01x_CR_UARTEN, uap->port.membase + UART010_CR);

 	uart_console_write(&uap->port, s, count, pl010_console_putchar);

 	/*
 	 *	Finally, wait for transmitter to become empty
 	 *	and restore the TCR
 	 */
 	do {
 		status = readb(uap->port.membase + UART01x_FR);
 		barrier();
 	} while (status & UART01x_FR_BUSY);
 	writel(old_cr, uap->port.membase + UART010_CR);

 	clk_disable(uap->clk);
 }

 static void __init
 pl010_console_get_options(struct uart_amba_port *uap, int *baud,
 			     int *parity, int *bits)
 {
 	if (readb(uap->port.membase + UART010_CR) & UART01x_CR_UARTEN) {
 		unsigned int lcr_h, quot;
 		lcr_h = readb(uap->port.membase + UART010_LCRH);

 		*parity = 'n';
 		if (lcr_h & UART01x_LCRH_PEN) {
 			if (lcr_h & UART01x_LCRH_EPS)
 				*parity = 'e';
 			else
 				*parity = 'o';
 		}

 		if ((lcr_h & 0x60) == UART01x_LCRH_WLEN_7)
 			*bits = 7;
 		else
 			*bits = 8;

 		quot = readb(uap->port.membase + UART010_LCRL) |
 		       readb(uap->port.membase + UART010_LCRM) << 8;
 		*baud = uap->port.uartclk / (16 * (quot + 1));
 	}
 }

 static int __init pl010_console_setup(struct console *co, char *options)
 {
 	struct uart_amba_port *uap;
 	int baud = 38400;
 	int bits = 8;
 	int parity = 'n';
 	int flow = 'n';
 	int ret;

 	/*
 	 * 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 >= UART_NR)
 		co->index = 0;
 	uap = amba_ports[co->index];
 	if (!uap)
 		return -ENODEV;

 	ret = clk_prepare(uap->clk);
 	if (ret)
 		return ret;

 	uap->port.uartclk = clk_get_rate(uap->clk);

 	if (options)
 		uart_parse_options(options, &baud, &parity, &bits, &flow);
 	else
 		pl010_console_get_options(uap, &baud, &parity, &bits);

 	return uart_set_options(&uap->port, co, baud, parity, bits, flow);
 }

 static struct uart_driver amba_reg;
 static struct console amba_console = {
 	.name		= "ttyAM",
 	.write		= pl010_console_write,
 	.device		= uart_console_device,
 	.setup		= pl010_console_setup,
 	.flags		= CON_PRINTBUFFER,
 	.index		= -1,
 	.data		= &amba_reg,
 };

 #define AMBA_CONSOLE	&amba_console
 #else
 #define AMBA_CONSOLE	NULL
 #endif

 static struct uart_driver amba_reg = {
 	.owner			= THIS_MODULE,
 	.driver_name		= "ttyAM",
 	.dev_name		= "ttyAM",
 	.major			= SERIAL_AMBA_MAJOR,
 	.minor			= SERIAL_AMBA_MINOR,
 	.nr			= UART_NR,
 	.cons			= AMBA_CONSOLE,
 };

 static int pl010_probe(struct amba_device *dev, const struct amba_id *id)
 {
 	struct uart_amba_port *uap;
 	void __iomem *base;
 	int i, ret;

 	for (i = 0; i < ARRAY_SIZE(amba_ports); i++)
 		if (amba_ports[i] == NULL)
 			break;

 	if (i == ARRAY_SIZE(amba_ports))
 		return -EBUSY;

 	uap = devm_kzalloc(&dev->dev, sizeof(struct uart_amba_port),
 			   GFP_KERNEL);
 	if (!uap)
 		return -ENOMEM;

 	base = devm_ioremap(&dev->dev, dev->res.start,
 			    resource_size(&dev->res));
 	if (!base)
 		return -ENOMEM;

 	uap->clk = devm_clk_get(&dev->dev, NULL);
 	if (IS_ERR(uap->clk))
 		return PTR_ERR(uap->clk);

 	uap->port.dev = &dev->dev;
 	uap->port.mapbase = dev->res.start;
 	uap->port.membase = base;
 	uap->port.iotype = UPIO_MEM;
 	uap->port.irq = dev->irq[0];
 	uap->port.fifosize = 16;
 	uap->port.ops = &amba_pl010_pops;
 	uap->port.flags = UPF_BOOT_AUTOCONF;
 	uap->port.line = i;
 	uap->dev = dev;
 	uap->data = dev_get_platdata(&dev->dev);

 	amba_ports[i] = uap;

 	amba_set_drvdata(dev, uap);
 	ret = uart_add_one_port(&amba_reg, &uap->port);
 	if (ret)
 		amba_ports[i] = NULL;

 	return ret;
 }

 static int pl010_remove(struct amba_device *dev)
 {
 	struct uart_amba_port *uap = amba_get_drvdata(dev);
 	int i;

 	uart_remove_one_port(&amba_reg, &uap->port);

 	for (i = 0; i < ARRAY_SIZE(amba_ports); i++)
 		if (amba_ports[i] == uap)
 			amba_ports[i] = NULL;

 	return 0;
 }

 #ifdef CONFIG_PM_SLEEP
 static int pl010_suspend(struct device *dev)
 {
 	struct uart_amba_port *uap = dev_get_drvdata(dev);

 	if (uap)
 		uart_suspend_port(&amba_reg, &uap->port);

 	return 0;
 }

 static int pl010_resume(struct device *dev)
 {
 	struct uart_amba_port *uap = dev_get_drvdata(dev);

 	if (uap)
 		uart_resume_port(&amba_reg, &uap->port);

 	return 0;
 }
 #endif

 static SIMPLE_DEV_PM_OPS(pl010_dev_pm_ops, pl010_suspend, pl010_resume);

 static struct amba_id pl010_ids[] = {
 	{
 		.id	= 0x00041010,
 		.mask	= 0x000fffff,
 	},
 	{ 0, 0 },
 };

 MODULE_DEVICE_TABLE(amba, pl010_ids);

 static struct amba_driver pl010_driver = {
 	.drv = {
 		.name	= "uart-pl010",
 		.pm	= &pl010_dev_pm_ops,
 	},
 	.id_table	= pl010_ids,
 	.probe		= pl010_probe,
 	.remove		= pl010_remove,
 };

 static int __init pl010_init(void)
 {
 	int ret;

 	printk(KERN_INFO "Serial: AMBA driver\n");

 	ret = uart_register_driver(&amba_reg);
 	if (ret == 0) {
 		ret = amba_driver_register(&pl010_driver);
 		if (ret)
 			uart_unregister_driver(&amba_reg);
 	}
 	return ret;
 }

 static void __exit pl010_exit(void)
 {
 	amba_driver_unregister(&pl010_driver);
 	uart_unregister_driver(&amba_reg);
 }

 module_init(pl010_init);
 module_exit(pl010_exit);

 MODULE_AUTHOR("ARM Ltd/Deep Blue Solutions Ltd");
 MODULE_DESCRIPTION("ARM AMBA serial port driver");
 MODULE_LICENSE("GPL");
	/*
	* Driver for AMBA serial ports
	*
	* Based on drivers/char/serial.c, by Linus Torvalds, Theodore Ts'o.
	*
	* Copyright 1999 ARM Limited
	* Copyright (C) 2000 Deep Blue Solutions Ltd.
	*
	* 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, write to the Free Software
	* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
	*
	* This is a generic driver for ARM AMBA-type serial ports. They
	* have a lot of 16550-like features, but are not register compatible.
	* Note that although they do have CTS, DCD and DSR inputs, they do
	* not have an RI input, nor do they have DTR or RTS outputs. If
	* required, these have to be supplied via some other means (eg, GPIO)
	* and hooked into this driver.
	*/

	#if defined(CONFIG_SERIAL_AMBA_PL010_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/device.h>
	#include <linux/tty.h>
	#include <linux/tty_flip.h>
	#include <linux/serial_core.h>
	#include <linux/serial.h>
	#include <linux/amba/bus.h>
	#include <linux/amba/serial.h>
	#include <linux/clk.h>
	#include <linux/slab.h>
	#include <linux/io.h>

	#define UART_NR 8

	#define SERIAL_AMBA_MAJOR 204
	#define SERIAL_AMBA_MINOR 16
	#define SERIAL_AMBA_NR UART_NR

	#define AMBA_ISR_PASS_LIMIT 256

	#define UART_RX_DATA(s) (((s) & UART01x_FR_RXFE) == 0)
	#define UART_TX_READY(s) (((s) & UART01x_FR_TXFF) == 0)

	#define UART_DUMMY_RSR_RX 256
	#define UART_PORT_SIZE 64

	/*
	* We wrap our port structure around the generic uart_port.
	*/
	struct uart_amba_port {
	struct uart_port port;
	struct clk *clk;
	struct amba_device *dev;
	struct amba_pl010_data *data;
	unsigned int old_status;
	};

	static void pl010_stop_tx(struct uart_port *port)
	{
	struct uart_amba_port *uap =
	container_of(port, struct uart_amba_port, port);
	unsigned int cr;

	cr = readb(uap->port.membase + UART010_CR);
	cr &= ~UART010_CR_TIE;
	writel(cr, uap->port.membase + UART010_CR);
	}

	static void pl010_start_tx(struct uart_port *port)
	{
	struct uart_amba_port *uap =
	container_of(port, struct uart_amba_port, port);
	unsigned int cr;

	cr = readb(uap->port.membase + UART010_CR);
	cr \|= UART010_CR_TIE;
	writel(cr, uap->port.membase + UART010_CR);
	}

	static void pl010_stop_rx(struct uart_port *port)
	{
	struct uart_amba_port *uap =
	container_of(port, struct uart_amba_port, port);
	unsigned int cr;

	cr = readb(uap->port.membase + UART010_CR);
	cr &= ~(UART010_CR_RIE \| UART010_CR_RTIE);
	writel(cr, uap->port.membase + UART010_CR);
	}

	static void pl010_disable_ms(struct uart_port *port)
	{
	struct uart_amba_port uap = (struct uart_amba_port )port;
	unsigned int cr;

	cr = readb(uap->port.membase + UART010_CR);
	cr &= ~UART010_CR_MSIE;
	writel(cr, uap->port.membase + UART010_CR);
	}

	static void pl010_enable_ms(struct uart_port *port)
	{
	struct uart_amba_port *uap =
	container_of(port, struct uart_amba_port, port);
	unsigned int cr;

	cr = readb(uap->port.membase + UART010_CR);
	cr \|= UART010_CR_MSIE;
	writel(cr, uap->port.membase + UART010_CR);
	}

	static void pl010_rx_chars(struct uart_amba_port *uap)
	{
	unsigned int status, ch, flag, rsr, max_count = 256;

	status = readb(uap->port.membase + UART01x_FR);
	while (UART_RX_DATA(status) && max_count--) {
	ch = readb(uap->port.membase + UART01x_DR);
	flag = TTY_NORMAL;

	uap->port.icount.rx++;

	/*
	* Note that the error handling code is
	* out of the main execution path
	*/
	rsr = readb(uap->port.membase + UART01x_RSR) \| UART_DUMMY_RSR_RX;
	if (unlikely(rsr & UART01x_RSR_ANY)) {
	writel(0, uap->port.membase + UART01x_ECR);

	if (rsr & UART01x_RSR_BE) {
	rsr &= ~(UART01x_RSR_FE \| UART01x_RSR_PE);
	uap->port.icount.brk++;
	if (uart_handle_break(&uap->port))
	goto ignore_char;
	} else if (rsr & UART01x_RSR_PE)
	uap->port.icount.parity++;
	else if (rsr & UART01x_RSR_FE)
	uap->port.icount.frame++;
	if (rsr & UART01x_RSR_OE)
	uap->port.icount.overrun++;

	rsr &= uap->port.read_status_mask;

	if (rsr & UART01x_RSR_BE)
	flag = TTY_BREAK;
	else if (rsr & UART01x_RSR_PE)
	flag = TTY_PARITY;
	else if (rsr & UART01x_RSR_FE)
	flag = TTY_FRAME;
	}

	if (uart_handle_sysrq_char(&uap->port, ch))
	goto ignore_char;

	uart_insert_char(&uap->port, rsr, UART01x_RSR_OE, ch, flag);

	ignore_char:
	status = readb(uap->port.membase + UART01x_FR);
	}
	spin_unlock(&uap->port.lock);
	tty_flip_buffer_push(&uap->port.state->port);
	spin_lock(&uap->port.lock);
	}

	static void pl010_tx_chars(struct uart_amba_port *uap)
	{
	struct circ_buf *xmit = &uap->port.state->xmit;
	int count;

	if (uap->port.x_char) {
	writel(uap->port.x_char, uap->port.membase + UART01x_DR);
	uap->port.icount.tx++;
	uap->port.x_char = 0;
	return;
	}
	if (uart_circ_empty(xmit) \|\| uart_tx_stopped(&uap->port)) {
	pl010_stop_tx(&uap->port);
	return;
	}

	count = uap->port.fifosize >> 1;
	do {
	writel(xmit->buf[xmit->tail], uap->port.membase + UART01x_DR);
	xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
	uap->port.icount.tx++;
	if (uart_circ_empty(xmit))
	break;
	} while (--count > 0);

	if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
	uart_write_wakeup(&uap->port);

	if (uart_circ_empty(xmit))
	pl010_stop_tx(&uap->port);
	}

	static void pl010_modem_status(struct uart_amba_port *uap)
	{
	unsigned int status, delta;

	writel(0, uap->port.membase + UART010_ICR);

	status = readb(uap->port.membase + UART01x_FR) & UART01x_FR_MODEM_ANY;

	delta = status ^ uap->old_status;
	uap->old_status = status;

	if (!delta)
	return;

	if (delta & UART01x_FR_DCD)
	uart_handle_dcd_change(&uap->port, status & UART01x_FR_DCD);

	if (delta & UART01x_FR_DSR)
	uap->port.icount.dsr++;

	if (delta & UART01x_FR_CTS)
	uart_handle_cts_change(&uap->port, status & UART01x_FR_CTS);

	wake_up_interruptible(&uap->port.state->port.delta_msr_wait);
	}

	static irqreturn_t pl010_int(int irq, void *dev_id)
	{
	struct uart_amba_port *uap = dev_id;
	unsigned int status, pass_counter = AMBA_ISR_PASS_LIMIT;
	int handled = 0;

	spin_lock(&uap->port.lock);

	status = readb(uap->port.membase + UART010_IIR);
	if (status) {
	do {
	if (status & (UART010_IIR_RTIS \| UART010_IIR_RIS))
	pl010_rx_chars(uap);
	if (status & UART010_IIR_MIS)
	pl010_modem_status(uap);
	if (status & UART010_IIR_TIS)
	pl010_tx_chars(uap);

	if (pass_counter-- == 0)
	break;

	status = readb(uap->port.membase + UART010_IIR);
	} while (status & (UART010_IIR_RTIS \| UART010_IIR_RIS \|
	UART010_IIR_TIS));
	handled = 1;
	}

	spin_unlock(&uap->port.lock);

	return IRQ_RETVAL(handled);
	}

	static unsigned int pl010_tx_empty(struct uart_port *port)
	{
	struct uart_amba_port *uap =
	container_of(port, struct uart_amba_port, port);
	unsigned int status = readb(uap->port.membase + UART01x_FR);
	return status & UART01x_FR_BUSY ? 0 : TIOCSER_TEMT;
	}

	static unsigned int pl010_get_mctrl(struct uart_port *port)
	{
	struct uart_amba_port *uap =
	container_of(port, struct uart_amba_port, port);
	unsigned int result = 0;
	unsigned int status;

	status = readb(uap->port.membase + UART01x_FR);
	if (status & UART01x_FR_DCD)
	result \|= TIOCM_CAR;
	if (status & UART01x_FR_DSR)
	result \|= TIOCM_DSR;
	if (status & UART01x_FR_CTS)
	result \|= TIOCM_CTS;

	return result;
	}

	static void pl010_set_mctrl(struct uart_port *port, unsigned int mctrl)
	{
	struct uart_amba_port *uap =
	container_of(port, struct uart_amba_port, port);

	if (uap->data)
	uap->data->set_mctrl(uap->dev, uap->port.membase, mctrl);
	}

	static void pl010_break_ctl(struct uart_port *port, int break_state)
	{
	struct uart_amba_port *uap =
	container_of(port, struct uart_amba_port, port);
	unsigned long flags;
	unsigned int lcr_h;

	spin_lock_irqsave(&uap->port.lock, flags);
	lcr_h = readb(uap->port.membase + UART010_LCRH);
	if (break_state == -1)
	lcr_h \|= UART01x_LCRH_BRK;
	else
	lcr_h &= ~UART01x_LCRH_BRK;
	writel(lcr_h, uap->port.membase + UART010_LCRH);
	spin_unlock_irqrestore(&uap->port.lock, flags);
	}

	static int pl010_startup(struct uart_port *port)
	{
	struct uart_amba_port *uap =
	container_of(port, struct uart_amba_port, port);
	int retval;

	/*
	* Try to enable the clock producer.
	*/
	retval = clk_prepare_enable(uap->clk);
	if (retval)
	goto out;

	uap->port.uartclk = clk_get_rate(uap->clk);

	/*
	* Allocate the IRQ
	*/
	retval = request_irq(uap->port.irq, pl010_int, 0, "uart-pl010", uap);
	if (retval)
	goto clk_dis;

	/*
	* initialise the old status of the modem signals
	*/
	uap->old_status = readb(uap->port.membase + UART01x_FR) & UART01x_FR_MODEM_ANY;

	/*
	* Finally, enable interrupts
	*/
	writel(UART01x_CR_UARTEN \| UART010_CR_RIE \| UART010_CR_RTIE,
	uap->port.membase + UART010_CR);

	return 0;

	clk_dis:
	clk_disable_unprepare(uap->clk);
	out:
	return retval;
	}

	static void pl010_shutdown(struct uart_port *port)
	{
	struct uart_amba_port *uap =
	container_of(port, struct uart_amba_port, port);

	/*
	* Free the interrupt
	*/
	free_irq(uap->port.irq, uap);

	/*
	* disable all interrupts, disable the port
	*/
	writel(0, uap->port.membase + UART010_CR);

	/* disable break condition and fifos */
	writel(readb(uap->port.membase + UART010_LCRH) &
	~(UART01x_LCRH_BRK \| UART01x_LCRH_FEN),
	uap->port.membase + UART010_LCRH);

	/*
	* Shut down the clock producer
	*/
	clk_disable_unprepare(uap->clk);
	}

	static void
	pl010_set_termios(struct uart_port port, struct ktermios termios,
	struct ktermios *old)
	{
	struct uart_amba_port *uap =
	container_of(port, struct uart_amba_port, port);
	unsigned int lcr_h, old_cr;
	unsigned long flags;
	unsigned int baud, quot;

	/*
	* Ask the core to calculate the divisor for us.
	*/
	baud = uart_get_baud_rate(port, termios, old, 0, uap->port.uartclk/16);
	quot = uart_get_divisor(port, baud);

	switch (termios->c_cflag & CSIZE) {
	case CS5:
	lcr_h = UART01x_LCRH_WLEN_5;
	break;
	case CS6:
	lcr_h = UART01x_LCRH_WLEN_6;
	break;
	case CS7:
	lcr_h = UART01x_LCRH_WLEN_7;
	break;
	default: // CS8
	lcr_h = UART01x_LCRH_WLEN_8;
	break;
	}
	if (termios->c_cflag & CSTOPB)
	lcr_h \|= UART01x_LCRH_STP2;
	if (termios->c_cflag & PARENB) {
	lcr_h \|= UART01x_LCRH_PEN;
	if (!(termios->c_cflag & PARODD))
	lcr_h \|= UART01x_LCRH_EPS;
	}
	if (uap->port.fifosize > 1)
	lcr_h \|= UART01x_LCRH_FEN;

	spin_lock_irqsave(&uap->port.lock, flags);

	/*
	* Update the per-port timeout.
	*/
	uart_update_timeout(port, termios->c_cflag, baud);

	uap->port.read_status_mask = UART01x_RSR_OE;
	if (termios->c_iflag & INPCK)
	uap->port.read_status_mask \|= UART01x_RSR_FE \| UART01x_RSR_PE;
	if (termios->c_iflag & (IGNBRK \| BRKINT \| PARMRK))
	uap->port.read_status_mask \|= UART01x_RSR_BE;

	/*
	* Characters to ignore
	*/
	uap->port.ignore_status_mask = 0;
	if (termios->c_iflag & IGNPAR)
	uap->port.ignore_status_mask \|= UART01x_RSR_FE \| UART01x_RSR_PE;
	if (termios->c_iflag & IGNBRK) {
	uap->port.ignore_status_mask \|= UART01x_RSR_BE;
	/*
	* If we're ignoring parity and break indicators,
	* ignore overruns too (for real raw support).
	*/
	if (termios->c_iflag & IGNPAR)
	uap->port.ignore_status_mask \|= UART01x_RSR_OE;
	}

	/*
	* Ignore all characters if CREAD is not set.
	*/
	if ((termios->c_cflag & CREAD) == 0)
	uap->port.ignore_status_mask \|= UART_DUMMY_RSR_RX;

	/* first, disable everything */
	old_cr = readb(uap->port.membase + UART010_CR) & ~UART010_CR_MSIE;

	if (UART_ENABLE_MS(port, termios->c_cflag))
	old_cr \|= UART010_CR_MSIE;

	writel(0, uap->port.membase + UART010_CR);

	/* Set baud rate */
	quot -= 1;
	writel((quot & 0xf00) >> 8, uap->port.membase + UART010_LCRM);
	writel(quot & 0xff, uap->port.membase + UART010_LCRL);

	/*
	* ----------v----------v----------v----------v-----
	* NOTE: MUST BE WRITTEN AFTER UARTLCR_M & UARTLCR_L
	* ----------^----------^----------^----------^-----
	*/
	writel(lcr_h, uap->port.membase + UART010_LCRH);
	writel(old_cr, uap->port.membase + UART010_CR);

	spin_unlock_irqrestore(&uap->port.lock, flags);
	}

	static void pl010_set_ldisc(struct uart_port port, struct ktermios termios)
	{
	if (termios->c_line == N_PPS) {
	port->flags \|= UPF_HARDPPS_CD;
	spin_lock_irq(&port->lock);
	pl010_enable_ms(port);
	spin_unlock_irq(&port->lock);
	} else {
	port->flags &= ~UPF_HARDPPS_CD;
	if (!UART_ENABLE_MS(port, termios->c_cflag)) {
	spin_lock_irq(&port->lock);
	pl010_disable_ms(port);
	spin_unlock_irq(&port->lock);
	}
	}
	}

	static const char pl010_type(struct uart_port port)
	{
	return port->type == PORT_AMBA ? "AMBA" : NULL;
	}

	/*
	* Release the memory region(s) being used by 'port'
	*/
	static void pl010_release_port(struct uart_port *port)
	{
	release_mem_region(port->mapbase, UART_PORT_SIZE);
	}

	/*
	* Request the memory region(s) being used by 'port'
	*/
	static int pl010_request_port(struct uart_port *port)
	{
	return request_mem_region(port->mapbase, UART_PORT_SIZE, "uart-pl010")
	!= NULL ? 0 : -EBUSY;
	}

	/*
	* Configure/autoconfigure the port.
	*/
	static void pl010_config_port(struct uart_port *port, int flags)
	{
	if (flags & UART_CONFIG_TYPE) {
	port->type = PORT_AMBA;
	pl010_request_port(port);
	}
	}

	/*
	* verify the new serial_struct (for TIOCSSERIAL).
	*/
	static int pl010_verify_port(struct uart_port port, struct serial_struct ser)
	{
	int ret = 0;
	if (ser->type != PORT_UNKNOWN && ser->type != PORT_AMBA)
	ret = -EINVAL;
	if (ser->irq < 0 \|\| ser->irq >= nr_irqs)
	ret = -EINVAL;
	if (ser->baud_base < 9600)
	ret = -EINVAL;
	return ret;
	}

	static const struct uart_ops amba_pl010_pops = {
	.tx_empty = pl010_tx_empty,
	.set_mctrl = pl010_set_mctrl,
	.get_mctrl = pl010_get_mctrl,
	.stop_tx = pl010_stop_tx,
	.start_tx = pl010_start_tx,
	.stop_rx = pl010_stop_rx,
	.enable_ms = pl010_enable_ms,
	.break_ctl = pl010_break_ctl,
	.startup = pl010_startup,
	.shutdown = pl010_shutdown,
	.set_termios = pl010_set_termios,
	.set_ldisc = pl010_set_ldisc,
	.type = pl010_type,
	.release_port = pl010_release_port,
	.request_port = pl010_request_port,
	.config_port = pl010_config_port,
	.verify_port = pl010_verify_port,
	};

	static struct uart_amba_port *amba_ports[UART_NR];

	#ifdef CONFIG_SERIAL_AMBA_PL010_CONSOLE

	static void pl010_console_putchar(struct uart_port *port, int ch)
	{
	struct uart_amba_port *uap =
	container_of(port, struct uart_amba_port, port);
	unsigned int status;

	do {
	status = readb(uap->port.membase + UART01x_FR);
	barrier();
	} while (!UART_TX_READY(status));
	writel(ch, uap->port.membase + UART01x_DR);
	}

	static void
	pl010_console_write(struct console co, const char s, unsigned int count)
	{
	struct uart_amba_port *uap = amba_ports[co->index];
	unsigned int status, old_cr;

	clk_enable(uap->clk);

	/*
	* First save the CR then disable the interrupts
	*/
	old_cr = readb(uap->port.membase + UART010_CR);
	writel(UART01x_CR_UARTEN, uap->port.membase + UART010_CR);

	uart_console_write(&uap->port, s, count, pl010_console_putchar);

	/*
	* Finally, wait for transmitter to become empty
	* and restore the TCR
	*/
	do {
	status = readb(uap->port.membase + UART01x_FR);
	barrier();
	} while (status & UART01x_FR_BUSY);
	writel(old_cr, uap->port.membase + UART010_CR);

	clk_disable(uap->clk);
	}

	static void __init
	pl010_console_get_options(struct uart_amba_port uap, int baud,
	int parity, int bits)
	{
	if (readb(uap->port.membase + UART010_CR) & UART01x_CR_UARTEN) {
	unsigned int lcr_h, quot;
	lcr_h = readb(uap->port.membase + UART010_LCRH);

	*parity = 'n';
	if (lcr_h & UART01x_LCRH_PEN) {
	if (lcr_h & UART01x_LCRH_EPS)
	*parity = 'e';
	else
	*parity = 'o';
	}

	if ((lcr_h & 0x60) == UART01x_LCRH_WLEN_7)
	*bits = 7;
	else
	*bits = 8;

	quot = readb(uap->port.membase + UART010_LCRL) \|
	readb(uap->port.membase + UART010_LCRM) << 8;
	baud = uap->port.uartclk / (16 (quot + 1));
	}
	}

	static int __init pl010_console_setup(struct console co, char options)
	{
	struct uart_amba_port *uap;
	int baud = 38400;
	int bits = 8;
	int parity = 'n';
	int flow = 'n';
	int ret;

	/*
	* 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 >= UART_NR)
	co->index = 0;
	uap = amba_ports[co->index];
	if (!uap)
	return -ENODEV;

	ret = clk_prepare(uap->clk);
	if (ret)
	return ret;

	uap->port.uartclk = clk_get_rate(uap->clk);

	if (options)
	uart_parse_options(options, &baud, &parity, &bits, &flow);
	else
	pl010_console_get_options(uap, &baud, &parity, &bits);

	return uart_set_options(&uap->port, co, baud, parity, bits, flow);
	}

	static struct uart_driver amba_reg;
	static struct console amba_console = {
	.name = "ttyAM",
	.write = pl010_console_write,
	.device = uart_console_device,
	.setup = pl010_console_setup,
	.flags = CON_PRINTBUFFER,
	.index = -1,
	.data = &amba_reg,
	};

	#define AMBA_CONSOLE &amba_console
	#else
	#define AMBA_CONSOLE NULL
	#endif

	static struct uart_driver amba_reg = {
	.owner = THIS_MODULE,
	.driver_name = "ttyAM",
	.dev_name = "ttyAM",
	.major = SERIAL_AMBA_MAJOR,
	.minor = SERIAL_AMBA_MINOR,
	.nr = UART_NR,
	.cons = AMBA_CONSOLE,
	};

	static int pl010_probe(struct amba_device dev, const struct amba_id id)
	{
	struct uart_amba_port *uap;
	void __iomem *base;
	int i, ret;

	for (i = 0; i < ARRAY_SIZE(amba_ports); i++)
	if (amba_ports[i] == NULL)
	break;

	if (i == ARRAY_SIZE(amba_ports))
	return -EBUSY;

	uap = devm_kzalloc(&dev->dev, sizeof(struct uart_amba_port),
	GFP_KERNEL);
	if (!uap)
	return -ENOMEM;

	base = devm_ioremap(&dev->dev, dev->res.start,
	resource_size(&dev->res));
	if (!base)
	return -ENOMEM;

	uap->clk = devm_clk_get(&dev->dev, NULL);
	if (IS_ERR(uap->clk))
	return PTR_ERR(uap->clk);

	uap->port.dev = &dev->dev;
	uap->port.mapbase = dev->res.start;
	uap->port.membase = base;
	uap->port.iotype = UPIO_MEM;
	uap->port.irq = dev->irq[0];
	uap->port.fifosize = 16;
	uap->port.ops = &amba_pl010_pops;
	uap->port.flags = UPF_BOOT_AUTOCONF;
	uap->port.line = i;
	uap->dev = dev;
	uap->data = dev_get_platdata(&dev->dev);

	amba_ports[i] = uap;

	amba_set_drvdata(dev, uap);
	ret = uart_add_one_port(&amba_reg, &uap->port);
	if (ret)
	amba_ports[i] = NULL;

	return ret;
	}

	static int pl010_remove(struct amba_device *dev)
	{
	struct uart_amba_port *uap = amba_get_drvdata(dev);
	int i;

	uart_remove_one_port(&amba_reg, &uap->port);

	for (i = 0; i < ARRAY_SIZE(amba_ports); i++)
	if (amba_ports[i] == uap)
	amba_ports[i] = NULL;

	return 0;
	}

	#ifdef CONFIG_PM_SLEEP
	static int pl010_suspend(struct device *dev)
	{
	struct uart_amba_port *uap = dev_get_drvdata(dev);

	if (uap)
	uart_suspend_port(&amba_reg, &uap->port);

	return 0;
	}

	static int pl010_resume(struct device *dev)
	{
	struct uart_amba_port *uap = dev_get_drvdata(dev);

	if (uap)
	uart_resume_port(&amba_reg, &uap->port);

	return 0;
	}
	#endif

	static SIMPLE_DEV_PM_OPS(pl010_dev_pm_ops, pl010_suspend, pl010_resume);

	static struct amba_id pl010_ids[] = {
	{
	.id = 0x00041010,
	.mask = 0x000fffff,
	},
	{ 0, 0 },
	};

	MODULE_DEVICE_TABLE(amba, pl010_ids);

	static struct amba_driver pl010_driver = {
	.drv = {
	.name = "uart-pl010",
	.pm = &pl010_dev_pm_ops,
	},
	.id_table = pl010_ids,
	.probe = pl010_probe,
	.remove = pl010_remove,
	};

	static int __init pl010_init(void)
	{
	int ret;

	printk(KERN_INFO "Serial: AMBA driver\n");

	ret = uart_register_driver(&amba_reg);
	if (ret == 0) {
	ret = amba_driver_register(&pl010_driver);
	if (ret)
	uart_unregister_driver(&amba_reg);
	}
	return ret;
	}

	static void __exit pl010_exit(void)
	{
	amba_driver_unregister(&pl010_driver);
	uart_unregister_driver(&amba_reg);
	}

	module_init(pl010_init);
	module_exit(pl010_exit);

	MODULE_AUTHOR("ARM Ltd/Deep Blue Solutions Ltd");
	MODULE_DESCRIPTION("ARM AMBA serial port driver");
	MODULE_LICENSE("GPL");