[PATCH v2] serial: Add driver for LPC32xx High Speed UARTs

[Roland Stigge]

This patch adds a driver for the 3 High Speed UARTs of the LPC32xx SoC that
support up to 921600bps. These UARTs are different from the 4 "Standard" UARTs
of the LPC32xx.

Signed-off-by: Roland Stigge <stigge@xxxxxxxxx>

---
Applies to v3.5-rc1

Changes since v1:
* Remove reference to MAJOR/MINOR numbers, dynamically allocate now
* Removed tty_schedule_flip() for framing error case
* Added tty_flip_buffer_push() for rx
* Use tty_port_tty_get() and tty_kref_put() in case tty is NULL
* Updated commit description
* Fixed locking in interrupt handler
* Write baudrate change (set_termios) back to termios

Thanks to Alan Cox for reviewing!

 Documentation/devicetree/bindings/tty/serial/nxp-lpc32xx-hsuart.txt |   14 
 drivers/tty/serial/Kconfig                                          |   19 
 drivers/tty/serial/Makefile                                         |    1 
 drivers/tty/serial/lpc32xx_hs.c                                     |  823 ++++++++++
 4 files changed, 857 insertions(+)

--- /dev/null
+++ linux-2.6/Documentation/devicetree/bindings/tty/serial/nxp-lpc32xx-hsuart.txt
@@ -0,0 +1,14 @@
+* NXP LPC32xx SoC High Speed UART
+
+Required properties:
+- compatible: Should be "nxp,lpc3220-hsuart"
+- reg: Should contain registers location and length
+- interrupts: Should contain interrupt
+
+Example:
+
+	uart1: serial@40014000 {
+		compatible = "nxp,lpc3220-hsuart";
+		reg = <0x40014000 0x1000>;
+		interrupts = <26 0>;
+	};
--- linux-2.6.orig/drivers/tty/serial/Kconfig
+++ linux-2.6/drivers/tty/serial/Kconfig
@@ -704,6 +704,25 @@ config SERIAL_PNX8XXX_CONSOLE
 	  If you have a MIPS-based Philips SoC such as PNX8550 or PNX8330
 	  and you want to use serial console, say Y. Otherwise, say N.
 
+config SERIAL_HS_LPC32XX
+	tristate "LPC32XX high speed serial port support"
+	depends on ARCH_LPC32XX && OF
+	select SERIAL_CORE
+	help
+	  Support for the LPC32XX high speed serial ports (up to 900kbps).
+	  Those are UARTs completely different from the Standard UARTs on the
+	  LPC32XX SoC.
+	  Choose M or Y here to build this driver.
+
+config SERIAL_HS_LPC32XX_CONSOLE
+	bool "Enable LPC32XX high speed UART serial console"
+	depends on SERIAL_HS_LPC32XX
+	select SERIAL_CORE_CONSOLE
+	help
+	  If you would like to be able to use one of the high speed serial
+	  ports on the LPC32XX as the console, you can do so by answering
+	  Y to this option.
+
 config SERIAL_CORE
 	tristate
 
--- linux-2.6.orig/drivers/tty/serial/Makefile
+++ linux-2.6/drivers/tty/serial/Makefile
@@ -34,6 +34,7 @@ obj-$(CONFIG_SERIAL_MUX) += mux.o
 obj-$(CONFIG_SERIAL_68328) += 68328serial.o
 obj-$(CONFIG_SERIAL_MCF) += mcf.o
 obj-$(CONFIG_SERIAL_PMACZILOG) += pmac_zilog.o
+obj-$(CONFIG_SERIAL_HS_LPC32XX) += lpc32xx_hs.o
 obj-$(CONFIG_SERIAL_DZ) += dz.o
 obj-$(CONFIG_SERIAL_ZS) += zs.o
 obj-$(CONFIG_SERIAL_SH_SCI) += sh-sci.o
--- /dev/null
+++ linux-2.6/drivers/tty/serial/lpc32xx_hs.c
@@ -0,0 +1,823 @@
+/*
+ * High Speed Serial Ports on NXP LPC32xx SoC
+ *
+ * Authors: Kevin Wells <kevin.wells@xxxxxxx>
+ *          Roland Stigge <stigge@xxxxxxxxx>
+ *
+ * Copyright (C) 2010 NXP Semiconductors
+ * Copyright (C) 2012 Roland Stigge
+ *
+ * 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.
+ */
+
+#include <linux/module.h>
+#include <linux/ioport.h>
+#include <linux/init.h>
+#include <linux/console.h>
+#include <linux/sysrq.h>
+#include <linux/tty.h>
+#include <linux/tty_flip.h>
+#include <linux/serial_core.h>
+#include <linux/serial.h>
+#include <linux/platform_device.h>
+#include <linux/delay.h>
+#include <linux/nmi.h>
+#include <linux/io.h>
+#include <linux/irq.h>
+#include <linux/gpio.h>
+#include <linux/of.h>
+#include <mach/platform.h>
+#include <mach/hardware.h>
+
+/*
+ * High Speed UART register offsets
+ */
+#define LPC32XX_HSUART_FIFO(x)			((x) + 0x00)
+#define LPC32XX_HSUART_LEVEL(x)			((x) + 0x04)
+#define LPC32XX_HSUART_IIR(x)			((x) + 0x08)
+#define LPC32XX_HSUART_CTRL(x)			((x) + 0x0C)
+#define LPC32XX_HSUART_RATE(x)			((x) + 0x10)
+
+#define LPC32XX_HSU_BREAK_DATA			(1 << 10)
+#define LPC32XX_HSU_ERROR_DATA			(1 << 9)
+#define LPC32XX_HSU_RX_EMPTY			(1 << 8)
+
+#define LPC32XX_HSU_TX_LEV(n)			(((n) >> 8) & 0xFF)
+#define LPC32XX_HSU_RX_LEV(n)			((n) & 0xFF)
+
+#define LPC32XX_HSU_TX_INT_SET			(1 << 6)
+#define LPC32XX_HSU_RX_OE_INT			(1 << 5)
+#define LPC32XX_HSU_BRK_INT			(1 << 4)
+#define LPC32XX_HSU_FE_INT			(1 << 3)
+#define LPC32XX_HSU_RX_TIMEOUT_INT		(1 << 2)
+#define LPC32XX_HSU_RX_TRIG_INT			(1 << 1)
+#define LPC32XX_HSU_TX_INT			(1 << 0)
+
+#define LPC32XX_HSU_HRTS_INV			(1 << 21)
+#define LPC32XX_HSU_HRTS_TRIG_8B		(0x0 << 19)
+#define LPC32XX_HSU_HRTS_TRIG_16B		(0x1 << 19)
+#define LPC32XX_HSU_HRTS_TRIG_32B		(0x2 << 19)
+#define LPC32XX_HSU_HRTS_TRIG_48B		(0x3 << 19)
+#define LPC32XX_HSU_HRTS_EN			(1 << 18)
+#define LPC32XX_HSU_TMO_DISABLED		(0x0 << 16)
+#define LPC32XX_HSU_TMO_INACT_4B		(0x1 << 16)
+#define LPC32XX_HSU_TMO_INACT_8B		(0x2 << 16)
+#define LPC32XX_HSU_TMO_INACT_16B		(0x3 << 16)
+#define LPC32XX_HSU_HCTS_INV			(1 << 15)
+#define LPC32XX_HSU_HCTS_EN			(1 << 14)
+#define LPC32XX_HSU_OFFSET(n)			((n) << 9)
+#define LPC32XX_HSU_BREAK			(1 << 8)
+#define LPC32XX_HSU_ERR_INT_EN			(1 << 7)
+#define LPC32XX_HSU_RX_INT_EN			(1 << 6)
+#define LPC32XX_HSU_TX_INT_EN			(1 << 5)
+#define LPC32XX_HSU_RX_TL1B			(0x0 << 2)
+#define LPC32XX_HSU_RX_TL4B			(0x1 << 2)
+#define LPC32XX_HSU_RX_TL8B			(0x2 << 2)
+#define LPC32XX_HSU_RX_TL16B			(0x3 << 2)
+#define LPC32XX_HSU_RX_TL32B			(0x4 << 2)
+#define LPC32XX_HSU_RX_TL48B			(0x5 << 2)
+#define LPC32XX_HSU_TX_TLEMPTY			(0x0 << 0)
+#define LPC32XX_HSU_TX_TL0B			(0x0 << 0)
+#define LPC32XX_HSU_TX_TL4B			(0x1 << 0)
+#define LPC32XX_HSU_TX_TL8B			(0x2 << 0)
+#define LPC32XX_HSU_TX_TL16B			(0x3 << 0)
+
+#define MODNAME "lpc32xx_hsuart"
+
+struct lpc32xx_hsuart_port {
+	struct uart_port port;
+};
+
+#define FIFO_READ_LIMIT 128
+#define MAX_PORTS 3
+#define LPC32XX_TTY_NAME "ttyTX"
+static struct lpc32xx_hsuart_port lpc32xx_hs_ports[MAX_PORTS];
+
+#ifdef CONFIG_SERIAL_HS_LPC32XX_CONSOLE
+static void wait_for_xmit_empty(struct uart_port *port)
+{
+	unsigned int timeout = 10000;
+
+	do {
+		if (LPC32XX_HSU_TX_LEV(readl(LPC32XX_HSUART_LEVEL(
+							port->membase))) == 0)
+			break;
+		if (--timeout == 0)
+			break;
+		udelay(1);
+	} while (1);
+}
+
+static void wait_for_xmit_ready(struct uart_port *port)
+{
+	unsigned int timeout = 10000;
+
+	while (1) {
+		if (LPC32XX_HSU_TX_LEV(readl(LPC32XX_HSUART_LEVEL(
+							port->membase))) < 32)
+			break;
+		if (--timeout == 0)
+			break;
+		udelay(1);
+	}
+}
+
+static void lpc32xx_hsuart_console_putchar(struct uart_port *port, int ch)
+{
+	wait_for_xmit_ready(port);
+	writel((u32)ch, LPC32XX_HSUART_FIFO(port->membase));
+}
+
+static void lpc32xx_hsuart_console_write(struct console *co, const char *s,
+					 unsigned int count)
+{
+	struct lpc32xx_hsuart_port *up = &lpc32xx_hs_ports[co->index];
+	unsigned long flags;
+	int locked = 1;
+
+	touch_nmi_watchdog();
+	local_irq_save(flags);
+	if (up->port.sysrq)
+		locked = 0;
+	else if (oops_in_progress)
+		locked = spin_trylock(&up->port.lock);
+	else
+		spin_lock(&up->port.lock);
+
+	uart_console_write(&up->port, s, count, lpc32xx_hsuart_console_putchar);
+	wait_for_xmit_empty(&up->port);
+
+	if (locked)
+		spin_unlock(&up->port.lock);
+	local_irq_restore(flags);
+}
+
+static int __init lpc32xx_hsuart_console_setup(struct console *co,
+					       char *options)
+{
+	struct uart_port *port;
+	int baud = 115200;
+	int bits = 8;
+	int parity = 'n';
+	int flow = 'n';
+
+	if (co->index >= MAX_PORTS)
+		co->index = 0;
+
+	port = &lpc32xx_hs_ports[co->index].port;
+	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 lpc32xx_hsuart_reg;
+static struct console lpc32xx_hsuart_console = {
+	.name		= LPC32XX_TTY_NAME,
+	.write		= lpc32xx_hsuart_console_write,
+	.device		= uart_console_device,
+	.setup		= lpc32xx_hsuart_console_setup,
+	.flags		= CON_PRINTBUFFER,
+	.index		= -1,
+	.data		= &lpc32xx_hsuart_reg,
+};
+
+static int __init lpc32xx_hsuart_console_init(void)
+{
+	register_console(&lpc32xx_hsuart_console);
+	return 0;
+}
+console_initcall(lpc32xx_hsuart_console_init);
+
+#define LPC32XX_HSUART_CONSOLE (&lpc32xx_hsuart_console)
+#else
+#define LPC32XX_HSUART_CONSOLE NULL
+#endif
+
+static struct uart_driver lpc32xx_hs_reg = {
+	.owner		= THIS_MODULE,
+	.driver_name	= MODNAME,
+	.dev_name	= LPC32XX_TTY_NAME,
+	.nr		= MAX_PORTS,
+	.cons		= LPC32XX_HSUART_CONSOLE,
+};
+static int uarts_registered;
+
+static unsigned int __serial_get_clock_div(unsigned long uartclk,
+					   unsigned long rate)
+{
+	u32 div, goodrate, hsu_rate, l_hsu_rate, comprate;
+	u32 rate_diff;
+
+	/* Find the closest divider to get the desired clock rate */
+	div = uartclk / rate;
+	goodrate = hsu_rate = (div / 14) - 1;
+	if (hsu_rate != 0)
+		hsu_rate--;
+
+	/* Tweak divider */
+	l_hsu_rate = hsu_rate + 3;
+	rate_diff = 0xFFFFFFFF;
+
+	while (hsu_rate < l_hsu_rate) {
+		comprate = uartclk / ((hsu_rate + 1) * 14);
+		if (abs(comprate - rate) < rate_diff) {
+			goodrate = hsu_rate;
+			rate_diff = abs(comprate - rate);
+		}
+
+		hsu_rate++;
+	}
+	if (hsu_rate > 0xFF)
+		hsu_rate = 0xFF;
+
+	return goodrate;
+}
+
+static void __serial_uart_flush(struct uart_port *port)
+{
+	u32 tmp;
+	int cnt = 0;
+
+	while ((readl(LPC32XX_HSUART_LEVEL(port->membase)) > 0) &&
+	       (cnt++ < FIFO_READ_LIMIT))
+		tmp = readl(LPC32XX_HSUART_FIFO(port->membase));
+}
+
+static void __serial_lpc32xx_rx(struct uart_port *port)
+{
+	unsigned int tmp, flag;
+	struct tty_struct *tty = tty_port_tty_get(&port->state->port);
+
+	if (!tty) {
+		/* Discard data: no tty available */
+		while (!(readl(LPC32XX_HSUART_FIFO(port->membase)) &
+			 LPC32XX_HSU_RX_EMPTY))
+			;
+
+		return;
+	}
+
+	/* Read data from FIFO and push into terminal */
+	tmp = readl(LPC32XX_HSUART_FIFO(port->membase));
+	while (!(tmp & LPC32XX_HSU_RX_EMPTY)) {
+		flag = TTY_NORMAL;
+		port->icount.rx++;
+
+		if (tmp & LPC32XX_HSU_ERROR_DATA) {
+			/* Framing error */
+			writel(LPC32XX_HSU_FE_INT,
+			       LPC32XX_HSUART_IIR(port->membase));
+			port->icount.frame++;
+			flag = TTY_FRAME;
+			tty_insert_flip_char(tty, 0, TTY_FRAME);
+		}
+
+		tty_insert_flip_char(tty, (tmp & 0xFF), flag);
+
+		tmp = readl(LPC32XX_HSUART_FIFO(port->membase));
+	}
+	tty_flip_buffer_push(tty);
+	tty_kref_put(tty);
+}
+
+static void __serial_lpc32xx_tx(struct uart_port *port)
+{
+	struct circ_buf *xmit = &port->state->xmit;
+	unsigned int tmp;
+
+	if (port->x_char) {
+		writel((u32)port->x_char, LPC32XX_HSUART_FIFO(port->membase));
+		port->icount.tx++;
+		port->x_char = 0;
+		return;
+	}
+
+	if (uart_circ_empty(xmit) || uart_tx_stopped(port))
+		goto exit_tx;
+
+	/* Transfer data */
+	while (LPC32XX_HSU_TX_LEV(readl(
+		LPC32XX_HSUART_LEVEL(port->membase))) < 64) {
+		writel((u32) xmit->buf[xmit->tail],
+		       LPC32XX_HSUART_FIFO(port->membase));
+		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);
+
+exit_tx:
+	if (uart_circ_empty(xmit)) {
+		tmp = readl(LPC32XX_HSUART_CTRL(port->membase));
+		tmp &= ~LPC32XX_HSU_TX_INT_EN;
+		writel(tmp, LPC32XX_HSUART_CTRL(port->membase));
+	}
+}
+
+static irqreturn_t serial_lpc32xx_interrupt(int irq, void *dev_id)
+{
+	struct uart_port *port = dev_id;
+	struct tty_struct *tty = tty_port_tty_get(&port->state->port);
+	u32 status;
+
+	spin_lock(&port->lock);
+
+	/* Read UART status and clear latched interrupts */
+	status = readl(LPC32XX_HSUART_IIR(port->membase));
+
+	if (status & LPC32XX_HSU_BRK_INT) {
+		/* Break received */
+		writel(LPC32XX_HSU_BRK_INT, LPC32XX_HSUART_IIR(port->membase));
+		port->icount.brk++;
+		uart_handle_break(port);
+	}
+
+	/* Framing error */
+	if (status & LPC32XX_HSU_FE_INT)
+		writel(LPC32XX_HSU_FE_INT, LPC32XX_HSUART_IIR(port->membase));
+
+	if (status & LPC32XX_HSU_RX_OE_INT) {
+		/* Receive FIFO overrun */
+		writel(LPC32XX_HSU_RX_OE_INT,
+		       LPC32XX_HSUART_IIR(port->membase));
+		port->icount.overrun++;
+		if (tty) {
+			tty_insert_flip_char(tty, 0, TTY_OVERRUN);
+			tty_schedule_flip(tty);
+		}
+	}
+
+	/* Data received? */
+	if (status & (LPC32XX_HSU_RX_TIMEOUT_INT | LPC32XX_HSU_RX_TRIG_INT)) {
+		__serial_lpc32xx_rx(port);
+		if (tty)
+			tty_flip_buffer_push(tty);
+	}
+
+	/* Transmit data request? */
+	if ((status & LPC32XX_HSU_TX_INT) && (!uart_tx_stopped(port))) {
+		writel(LPC32XX_HSU_TX_INT, LPC32XX_HSUART_IIR(port->membase));
+		__serial_lpc32xx_tx(port);
+	}
+
+	spin_unlock(&port->lock);
+	tty_kref_put(tty);
+
+	return IRQ_HANDLED;
+}
+
+/* port->lock is not held.  */
+static unsigned int serial_lpc32xx_tx_empty(struct uart_port *port)
+{
+	unsigned int ret = 0;
+
+	if (LPC32XX_HSU_TX_LEV(readl(LPC32XX_HSUART_LEVEL(port->membase))) == 0)
+		ret = TIOCSER_TEMT;
+
+	return ret;
+}
+
+/* port->lock held by caller.  */
+static void serial_lpc32xx_set_mctrl(struct uart_port *port,
+				     unsigned int mctrl)
+{
+	/* No signals are supported on HS UARTs */
+}
+
+/* port->lock is held by caller and interrupts are disabled.  */
+static unsigned int serial_lpc32xx_get_mctrl(struct uart_port *port)
+{
+	/* No signals are supported on HS UARTs */
+	return TIOCM_CAR | TIOCM_DSR | TIOCM_CTS;
+}
+
+/* port->lock held by caller.  */
+static void serial_lpc32xx_stop_tx(struct uart_port *port)
+{
+	u32 tmp;
+
+	tmp = readl(LPC32XX_HSUART_CTRL(port->membase));
+	tmp &= ~LPC32XX_HSU_TX_INT_EN;
+	writel(tmp, LPC32XX_HSUART_CTRL(port->membase));
+}
+
+/* port->lock held by caller.  */
+static void serial_lpc32xx_start_tx(struct uart_port *port)
+{
+	u32 tmp;
+
+	__serial_lpc32xx_tx(port);
+	tmp = readl(LPC32XX_HSUART_CTRL(port->membase));
+	tmp |= LPC32XX_HSU_TX_INT_EN;
+	writel(tmp, LPC32XX_HSUART_CTRL(port->membase));
+}
+
+/* port->lock held by caller.  */
+static void serial_lpc32xx_stop_rx(struct uart_port *port)
+{
+	u32 tmp;
+
+	tmp = readl(LPC32XX_HSUART_CTRL(port->membase));
+	tmp &= ~(LPC32XX_HSU_RX_INT_EN | LPC32XX_HSU_ERR_INT_EN);
+	writel(tmp, LPC32XX_HSUART_CTRL(port->membase));
+
+	writel((LPC32XX_HSU_BRK_INT | LPC32XX_HSU_RX_OE_INT |
+		LPC32XX_HSU_FE_INT), LPC32XX_HSUART_IIR(port->membase));
+}
+
+/* port->lock held by caller.  */
+static void serial_lpc32xx_enable_ms(struct uart_port *port)
+{
+	/* Modem status is not supported */
+}
+
+/* port->lock is not held.  */
+static void serial_lpc32xx_break_ctl(struct uart_port *port,
+				     int break_state)
+{
+	unsigned long flags;
+	u32 tmp;
+
+	spin_lock_irqsave(&port->lock, flags);
+	tmp = readl(LPC32XX_HSUART_CTRL(port->membase));
+	if (break_state != 0)
+		tmp |= LPC32XX_HSU_BREAK;
+	else
+		tmp &= ~LPC32XX_HSU_BREAK;
+	writel(tmp, LPC32XX_HSUART_CTRL(port->membase));
+	spin_unlock_irqrestore(&port->lock, flags);
+}
+
+/* LPC3250 Errata HSUART.1: Hang workaround via loopback mode on inactivity */
+static void lpc32xx_loopback_set(resource_size_t mapbase, int state)
+{
+	int bit;
+	u32 tmp;
+
+	switch (mapbase) {
+	case LPC32XX_HS_UART1_BASE:
+		bit = 0;
+		break;
+	case LPC32XX_HS_UART2_BASE:
+		bit = 1;
+		break;
+	case LPC32XX_HS_UART7_BASE:
+		bit = 6;
+		break;
+	default:
+		WARN(1, "lpc32xx_hs: Warning: Unknown port at %08x\n", mapbase);
+		return;
+	}
+
+	tmp = readl(LPC32XX_UARTCTL_CLOOP);
+	if (state)
+		tmp |= (1 << bit);
+	else
+		tmp &= ~(1 << bit);
+	writel(tmp, LPC32XX_UARTCTL_CLOOP);
+}
+
+/* port->lock is not held.  */
+static int serial_lpc32xx_startup(struct uart_port *port)
+{
+	int retval;
+	unsigned long flags;
+	u32 tmp;
+
+	spin_lock_irqsave(&port->lock, flags);
+
+	__serial_uart_flush(port);
+
+	writel((LPC32XX_HSU_TX_INT | LPC32XX_HSU_FE_INT |
+		LPC32XX_HSU_BRK_INT | LPC32XX_HSU_RX_OE_INT),
+	       LPC32XX_HSUART_IIR(port->membase));
+
+	writel(0xFF, LPC32XX_HSUART_RATE(port->membase));
+
+	/*
+	 * Set receiver timeout, HSU offset of 20, no break, no interrupts,
+	 * and default FIFO trigger levels
+	 */
+	tmp = LPC32XX_HSU_TX_TL8B | LPC32XX_HSU_RX_TL32B |
+		LPC32XX_HSU_OFFSET(20) | LPC32XX_HSU_TMO_INACT_4B;
+	writel(tmp, LPC32XX_HSUART_CTRL(port->membase));
+
+	lpc32xx_loopback_set(port->mapbase, 0); /* get out of loopback mode */
+
+	spin_unlock_irqrestore(&port->lock, flags);
+
+	retval = request_irq(port->irq, serial_lpc32xx_interrupt,
+			     0, MODNAME, port);
+	if (!retval)
+		writel((tmp | LPC32XX_HSU_RX_INT_EN | LPC32XX_HSU_ERR_INT_EN),
+		       LPC32XX_HSUART_CTRL(port->membase));
+
+	return retval;
+}
+
+/* port->lock is not held.  */
+static void serial_lpc32xx_shutdown(struct uart_port *port)
+{
+	u32 tmp;
+	unsigned long flags;
+
+	spin_lock_irqsave(&port->lock, flags);
+
+	tmp = LPC32XX_HSU_TX_TL8B | LPC32XX_HSU_RX_TL32B |
+		LPC32XX_HSU_OFFSET(20) | LPC32XX_HSU_TMO_INACT_4B;
+	writel(tmp, LPC32XX_HSUART_CTRL(port->membase));
+
+	lpc32xx_loopback_set(port->mapbase, 1); /* go to loopback mode */
+
+	spin_unlock_irqrestore(&port->lock, flags);
+
+	free_irq(port->irq, port);
+}
+
+/* port->lock is not held.  */
+static void serial_lpc32xx_set_termios(struct uart_port *port,
+				       struct ktermios *termios,
+				       struct ktermios *old)
+{
+	unsigned long flags;
+	unsigned int baud, quot;
+	u32 tmp;
+
+	/* Always 8-bit, no parity, 1 stop bit */
+	termios->c_cflag &= ~(CSIZE | CSTOPB | PARENB | PARODD);
+	termios->c_cflag |= CS8;
+
+	termios->c_cflag &= ~(HUPCL | CMSPAR | CLOCAL | CRTSCTS);
+
+	baud = uart_get_baud_rate(port, termios, old, 0,
+				  port->uartclk / 14);
+
+	quot = __serial_get_clock_div(port->uartclk, baud);
+
+	spin_lock_irqsave(&port->lock, flags);
+
+	/* Ignore characters? */
+	tmp = readl(LPC32XX_HSUART_CTRL(port->membase));
+	if ((termios->c_cflag & CREAD) == 0)
+		tmp &= ~(LPC32XX_HSU_RX_INT_EN | LPC32XX_HSU_ERR_INT_EN);
+	else
+		tmp |= LPC32XX_HSU_RX_INT_EN | LPC32XX_HSU_ERR_INT_EN;
+	writel(tmp, LPC32XX_HSUART_CTRL(port->membase));
+
+	writel(quot, LPC32XX_HSUART_RATE(port->membase));
+
+	uart_update_timeout(port, termios->c_cflag, baud);
+
+	spin_unlock_irqrestore(&port->lock, flags);
+
+	/* Don't rewrite B0 */
+	if (tty_termios_baud_rate(termios))
+		tty_termios_encode_baud_rate(termios, baud, baud);
+}
+
+static const char *serial_lpc32xx_type(struct uart_port *port)
+{
+	return MODNAME;
+}
+
+static void serial_lpc32xx_release_port(struct uart_port *port)
+{
+	if ((port->iotype == UPIO_MEM32) && (port->mapbase)) {
+		if (port->flags & UPF_IOREMAP) {
+			iounmap(port->membase);
+			port->membase = NULL;
+		}
+
+		release_mem_region(port->mapbase, SZ_4K);
+	}
+}
+
+static int serial_lpc32xx_request_port(struct uart_port *port)
+{
+	int ret = -ENODEV;
+
+	if ((port->iotype == UPIO_MEM32) && (port->mapbase)) {
+		ret = 0;
+
+		if (!request_mem_region(port->mapbase, SZ_4K, MODNAME))
+			ret = -EBUSY;
+		else if (port->flags & UPF_IOREMAP) {
+			port->membase = ioremap(port->mapbase, SZ_4K);
+			if (!port->membase) {
+				release_mem_region(port->mapbase, SZ_4K);
+				ret = -ENOMEM;
+			}
+		}
+	}
+
+	return ret;
+}
+
+static void serial_lpc32xx_config_port(struct uart_port *port, int uflags)
+{
+	int ret;
+
+	ret = serial_lpc32xx_request_port(port);
+	if (ret < 0)
+		return;
+	port->type = PORT_UART00;
+	port->fifosize = 64;
+
+	__serial_uart_flush(port);
+
+	writel((LPC32XX_HSU_TX_INT | LPC32XX_HSU_FE_INT |
+		LPC32XX_HSU_BRK_INT | LPC32XX_HSU_RX_OE_INT),
+	       LPC32XX_HSUART_IIR(port->membase));
+
+	writel(0xFF, LPC32XX_HSUART_RATE(port->membase));
+
+	/* Set receiver timeout, HSU offset of 20, no break, no interrupts,
+	   and default FIFO trigger levels */
+	writel(LPC32XX_HSU_TX_TL8B | LPC32XX_HSU_RX_TL32B |
+	       LPC32XX_HSU_OFFSET(20) | LPC32XX_HSU_TMO_INACT_4B,
+	       LPC32XX_HSUART_CTRL(port->membase));
+}
+
+static int serial_lpc32xx_verify_port(struct uart_port *port,
+				      struct serial_struct *ser)
+{
+	int ret = 0;
+
+	if (ser->type != PORT_UART00)
+		ret = -EINVAL;
+
+	return ret;
+}
+
+static struct uart_ops serial_lpc32xx_pops = {
+	.tx_empty	= serial_lpc32xx_tx_empty,
+	.set_mctrl	= serial_lpc32xx_set_mctrl,
+	.get_mctrl	= serial_lpc32xx_get_mctrl,
+	.stop_tx	= serial_lpc32xx_stop_tx,
+	.start_tx	= serial_lpc32xx_start_tx,
+	.stop_rx	= serial_lpc32xx_stop_rx,
+	.enable_ms	= serial_lpc32xx_enable_ms,
+	.break_ctl	= serial_lpc32xx_break_ctl,
+	.startup	= serial_lpc32xx_startup,
+	.shutdown	= serial_lpc32xx_shutdown,
+	.set_termios	= serial_lpc32xx_set_termios,
+	.type		= serial_lpc32xx_type,
+	.release_port	= serial_lpc32xx_release_port,
+	.request_port	= serial_lpc32xx_request_port,
+	.config_port	= serial_lpc32xx_config_port,
+	.verify_port	= serial_lpc32xx_verify_port,
+};
+
+/*
+ * Register a set of serial devices attached to a platform device
+ */
+static int __devinit serial_hs_lpc32xx_probe(struct platform_device *pdev)
+{
+	struct lpc32xx_hsuart_port *p = &lpc32xx_hs_ports[uarts_registered];
+	int ret = 0;
+	struct resource *res;
+
+	if (uarts_registered >= MAX_PORTS) {
+		dev_err(&pdev->dev,
+			"Error: Number of possible ports exceeded (%d)!\n",
+			uarts_registered + 1);
+		return -ENXIO;
+	}
+
+	memset(p, 0, sizeof(*p));
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	if (!res) {
+		dev_err(&pdev->dev,
+			"Error getting mem resource for HS UART port %d\n",
+			uarts_registered);
+		return -ENXIO;
+	}
+	p->port.mapbase = res->start;
+	p->port.membase = NULL;
+
+	p->port.irq = platform_get_irq(pdev, 0);
+	if (p->port.irq < 0) {
+		dev_err(&pdev->dev, "Error getting irq for HS UART port %d\n",
+			uarts_registered);
+		return p->port.irq;
+	}
+
+	p->port.iotype = UPIO_MEM32;
+	p->port.uartclk = LPC32XX_MAIN_OSC_FREQ;
+	p->port.regshift = 2;
+	p->port.flags = UPF_BOOT_AUTOCONF | UPF_FIXED_PORT | UPF_IOREMAP;
+	p->port.dev = &pdev->dev;
+	p->port.ops = &serial_lpc32xx_pops;
+	p->port.line = uarts_registered++;
+	spin_lock_init(&p->port.lock);
+
+	/* send port to loopback mode by default */
+	lpc32xx_loopback_set(p->port.mapbase, 1);
+
+	ret = uart_add_one_port(&lpc32xx_hs_reg, &p->port);
+
+	platform_set_drvdata(pdev, p);
+
+	return ret;
+}
+
+/*
+ * Remove serial ports registered against a platform device.
+ */
+static int __devexit serial_hs_lpc32xx_remove(struct platform_device *pdev)
+{
+	struct lpc32xx_hsuart_port *p = platform_get_drvdata(pdev);
+
+	uart_remove_one_port(&lpc32xx_hs_reg, &p->port);
+
+	return 0;
+}
+
+
+#ifdef CONFIG_PM
+static int serial_hs_lpc32xx_suspend(struct platform_device *pdev,
+				     pm_message_t state)
+{
+	struct lpc32xx_hsuart_port *p = platform_get_drvdata(pdev);
+
+	uart_suspend_port(&lpc32xx_hs_reg, &p->port);
+
+	return 0;
+}
+
+static int serial_hs_lpc32xx_resume(struct platform_device *pdev)
+{
+	struct lpc32xx_hsuart_port *p = platform_get_drvdata(pdev);
+
+	uart_resume_port(&lpc32xx_hs_reg, &p->port);
+
+	return 0;
+}
+#else
+#define serial_hs_lpc32xx_suspend	NULL
+#define serial_hs_lpc32xx_resume	NULL
+#endif
+
+static const struct of_device_id serial_hs_lpc32xx_dt_ids[] = {
+	{ .compatible = "nxp,lpc3220-hsuart" },
+	{ /* sentinel */ }
+};
+
+MODULE_DEVICE_TABLE(of, serial_hs_lpc32xx_dt_ids);
+
+static struct platform_driver serial_hs_lpc32xx_driver = {
+	.probe		= serial_hs_lpc32xx_probe,
+	.remove		= __devexit_p(serial_hs_lpc32xx_remove),
+	.suspend	= serial_hs_lpc32xx_suspend,
+	.resume		= serial_hs_lpc32xx_resume,
+	.driver		= {
+		.name	= MODNAME,
+		.owner	= THIS_MODULE,
+		.of_match_table	= serial_hs_lpc32xx_dt_ids,
+	},
+};
+
+static int __init lpc32xx_hsuart_init(void)
+{
+	int ret;
+
+	ret = uart_register_driver(&lpc32xx_hs_reg);
+	if (ret)
+		return ret;
+
+	ret = platform_driver_register(&serial_hs_lpc32xx_driver);
+	if (ret)
+		uart_unregister_driver(&lpc32xx_hs_reg);
+
+	return ret;
+}
+
+static void __exit lpc32xx_hsuart_exit(void)
+{
+	platform_driver_unregister(&serial_hs_lpc32xx_driver);
+	uart_unregister_driver(&lpc32xx_hs_reg);
+}
+
+module_init(lpc32xx_hsuart_init);
+module_exit(lpc32xx_hsuart_exit);
+
+MODULE_AUTHOR("Kevin Wells <kevin.wells@xxxxxxx>");
+MODULE_AUTHOR("Roland Stigge <stigge@xxxxxxxxx>");
+MODULE_DESCRIPTION("NXP LPC32XX High Speed UART driver");
+MODULE_LICENSE("GPL");
--
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