1 files changed, 825 insertions, 0 deletions

diff --git a/drivers/tty/serial/amba-pl010.c b/drivers/tty/serial/amba-pl010.c
new file mode 100644
index 000000000..af27fb8ec
--- /dev/null
+++ b/drivers/tty/serial/amba-pl010.c
@@ -0,0 +1,825 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ *  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 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.
+ */
+
+#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_port *port)
+{
+	unsigned int status, ch, flag, rsr, max_count = 256;
+
+	status = readb(port->membase + UART01x_FR);
+	while (UART_RX_DATA(status) && max_count--) {
+		ch = readb(port->membase + UART01x_DR);
+		flag = TTY_NORMAL;
+
+		port->icount.rx++;
+
+		/*
+		 * Note that the error handling code is
+		 * out of the main execution path
+		 */
+		rsr = readb(port->membase + UART01x_RSR) | UART_DUMMY_RSR_RX;
+		if (unlikely(rsr & UART01x_RSR_ANY)) {
+			writel(0, port->membase + UART01x_ECR);
+
+			if (rsr & UART01x_RSR_BE) {
+				rsr &= ~(UART01x_RSR_FE | UART01x_RSR_PE);
+				port->icount.brk++;
+				if (uart_handle_break(port))
+					goto ignore_char;
+			} else if (rsr & UART01x_RSR_PE)
+				port->icount.parity++;
+			else if (rsr & UART01x_RSR_FE)
+				port->icount.frame++;
+			if (rsr & UART01x_RSR_OE)
+				port->icount.overrun++;
+
+			rsr &= 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(port, ch))
+			goto ignore_char;
+
+		uart_insert_char(port, rsr, UART01x_RSR_OE, ch, flag);
+
+	ignore_char:
+		status = readb(port->membase + UART01x_FR);
+	}
+	tty_flip_buffer_push(&port->state->port);
+}
+
+static void pl010_tx_chars(struct uart_port *port)
+{
+	struct circ_buf *xmit = &port->state->xmit;
+	int count;
+
+	if (port->x_char) {
+		writel(port->x_char, port->membase + UART01x_DR);
+		port->icount.tx++;
+		port->x_char = 0;
+		return;
+	}
+	if (uart_circ_empty(xmit) || uart_tx_stopped(port)) {
+		pl010_stop_tx(port);
+		return;
+	}
+
+	count = port->fifosize >> 1;
+	do {
+		writel(xmit->buf[xmit->tail], port->membase + UART01x_DR);
+		xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
+		port->icount.tx++;
+		if (uart_circ_empty(xmit))
+			break;
+	} while (--count > 0);
+
+	if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
+		uart_write_wakeup(port);
+
+	if (uart_circ_empty(xmit))
+		pl010_stop_tx(port);
+}
+
+static void pl010_modem_status(struct uart_amba_port *uap)
+{
+	struct uart_port *port = &uap->port;
+	unsigned int status, delta;
+
+	writel(0, port->membase + UART010_ICR);
+
+	status = readb(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(port, status & UART01x_FR_DCD);
+
+	if (delta & UART01x_FR_DSR)
+		port->icount.dsr++;
+
+	if (delta & UART01x_FR_CTS)
+		uart_handle_cts_change(port, status & UART01x_FR_CTS);
+
+	wake_up_interruptible(&port->state->port.delta_msr_wait);
+}
+
+static irqreturn_t pl010_int(int irq, void *dev_id)
+{
+	struct uart_amba_port *uap = dev_id;
+	struct uart_port *port = &uap->port;
+	unsigned int status, pass_counter = AMBA_ISR_PASS_LIMIT;
+	int handled = 0;
+
+	spin_lock(&port->lock);
+
+	status = readb(port->membase + UART010_IIR);
+	if (status) {
+		do {
+			if (status & (UART010_IIR_RTIS | UART010_IIR_RIS))
+				pl010_rx_chars(port);
+			if (status & UART010_IIR_MIS)
+				pl010_modem_status(uap);
+			if (status & UART010_IIR_TIS)
+				pl010_tx_chars(port);
+
+			if (pass_counter-- == 0)
+				break;
+
+			status = readb(port->membase + UART010_IIR);
+		} while (status & (UART010_IIR_RTIS | UART010_IIR_RIS |
+				   UART010_IIR_TIS));
+		handled = 1;
+	}
+
+	spin_unlock(&port->lock);
+
+	return IRQ_RETVAL(handled);
+}
+
+static unsigned int pl010_tx_empty(struct uart_port *port)
+{
+	unsigned int status = readb(port->membase + UART01x_FR);
+
+	return status & UART01x_FR_BUSY ? 0 : TIOCSER_TEMT;
+}
+
+static unsigned int pl010_get_mctrl(struct uart_port *port)
+{
+	unsigned int result = 0;
+	unsigned int status;
+
+	status = readb(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, port->membase, mctrl);
+}
+
+static void pl010_break_ctl(struct uart_port *port, int break_state)
+{
+	unsigned long flags;
+	unsigned int lcr_h;
+
+	spin_lock_irqsave(&port->lock, flags);
+	lcr_h = readb(port->membase + UART010_LCRH);
+	if (break_state == -1)
+		lcr_h |= UART01x_LCRH_BRK;
+	else
+		lcr_h &= ~UART01x_LCRH_BRK;
+	writel(lcr_h, port->membase + UART010_LCRH);
+	spin_unlock_irqrestore(&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;
+
+	port->uartclk = clk_get_rate(uap->clk);
+
+	/*
+	 * Allocate the IRQ
+	 */
+	retval = request_irq(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(port->membase + UART01x_FR) & UART01x_FR_MODEM_ANY;
+
+	/*
+	 * Finally, enable interrupts
+	 */
+	writel(UART01x_CR_UARTEN | UART010_CR_RIE | UART010_CR_RTIE,
+	       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(port->irq, uap);
+
+	/*
+	 * disable all interrupts, disable the port
+	 */
+	writel(0, port->membase + UART010_CR);
+
+	/* disable break condition and fifos */
+	writel(readb(port->membase + UART010_LCRH) &
+		~(UART01x_LCRH_BRK | UART01x_LCRH_FEN),
+	       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,
+		  const struct ktermios *old)
+{
+	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, 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 (port->fifosize > 1)
+		lcr_h |= UART01x_LCRH_FEN;
+
+	spin_lock_irqsave(&port->lock, flags);
+
+	/*
+	 * Update the per-port timeout.
+	 */
+	uart_update_timeout(port, termios->c_cflag, baud);
+
+	port->read_status_mask = UART01x_RSR_OE;
+	if (termios->c_iflag & INPCK)
+		port->read_status_mask |= UART01x_RSR_FE | UART01x_RSR_PE;
+	if (termios->c_iflag & (IGNBRK | BRKINT | PARMRK))
+		port->read_status_mask |= UART01x_RSR_BE;
+
+	/*
+	 * Characters to ignore
+	 */
+	port->ignore_status_mask = 0;
+	if (termios->c_iflag & IGNPAR)
+		port->ignore_status_mask |= UART01x_RSR_FE | UART01x_RSR_PE;
+	if (termios->c_iflag & IGNBRK) {
+		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)
+			port->ignore_status_mask |= UART01x_RSR_OE;
+	}
+
+	/*
+	 * Ignore all characters if CREAD is not set.
+	 */
+	if ((termios->c_cflag & CREAD) == 0)
+		port->ignore_status_mask |= UART_DUMMY_RSR_RX;
+
+	old_cr = readb(port->membase + UART010_CR) & ~UART010_CR_MSIE;
+
+	if (UART_ENABLE_MS(port, termios->c_cflag))
+		old_cr |= UART010_CR_MSIE;
+
+	/* Set baud rate */
+	quot -= 1;
+	writel((quot & 0xf00) >> 8, port->membase + UART010_LCRM);
+	writel(quot & 0xff, port->membase + UART010_LCRL);
+
+	/*
+	 * ----------v----------v----------v----------v-----
+	 * NOTE: MUST BE WRITTEN AFTER UARTLCR_M & UARTLCR_L
+	 * ----------^----------^----------^----------^-----
+	 */
+	writel(lcr_h, port->membase + UART010_LCRH);
+	writel(old_cr, port->membase + UART010_CR);
+
+	spin_unlock_irqrestore(&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, unsigned char ch)
+{
+	unsigned int status;
+
+	do {
+		status = readb(port->membase + UART01x_FR);
+		barrier();
+	} while (!UART_TX_READY(status));
+	writel(ch, 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];
+	struct uart_port *port = &uap->port;
+	unsigned int status, old_cr;
+
+	clk_enable(uap->clk);
+
+	/*
+	 *	First save the CR then disable the interrupts
+	 */
+	old_cr = readb(port->membase + UART010_CR);
+	writel(UART01x_CR_UARTEN, port->membase + UART010_CR);
+
+	uart_console_write(port, s, count, pl010_console_putchar);
+
+	/*
+	 *	Finally, wait for transmitter to become empty
+	 *	and restore the TCR
+	 */
+	do {
+		status = readb(port->membase + UART01x_FR);
+		barrier();
+	} while (status & UART01x_FR_BUSY);
+	writel(old_cr, 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 DEFINE_MUTEX(amba_reg_lock);
+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.has_sysrq = IS_ENABLED(CONFIG_SERIAL_AMBA_PL010_CONSOLE);
+	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);
+
+	mutex_lock(&amba_reg_lock);
+	if (!amba_reg.state) {
+		ret = uart_register_driver(&amba_reg);
+		if (ret < 0) {
+			mutex_unlock(&amba_reg_lock);
+			dev_err(uap->port.dev,
+				"Failed to register AMBA-PL010 driver\n");
+			return ret;
+		}
+	}
+	mutex_unlock(&amba_reg_lock);
+
+	ret = uart_add_one_port(&amba_reg, &uap->port);
+	if (ret)
+		amba_ports[i] = NULL;
+
+	return ret;
+}
+
+static void pl010_remove(struct amba_device *dev)
+{
+	struct uart_amba_port *uap = amba_get_drvdata(dev);
+	int i;
+	bool busy = false;
+
+	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;
+		else if (amba_ports[i])
+			busy = true;
+
+	if (!busy)
+		uart_unregister_driver(&amba_reg);
+}
+
+#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 const 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)
+{
+	printk(KERN_INFO "Serial: AMBA driver\n");
+
+	return  amba_driver_register(&pl010_driver);
+}
+
+static void __exit pl010_exit(void)
+{
+	amba_driver_unregister(&pl010_driver);
+}
+
+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");