[deliverable/linux.git] / drivers / tty / serial / ar933x_uart.c

/*
 *  Atheros AR933X SoC built-in UART driver
 *
 *  Copyright (C) 2011 Gabor Juhos <juhosg@openwrt.org>
 *
 *  Based on drivers/char/serial.c, by Linus Torvalds, Theodore Ts'o.
 *
 *  This program is free software; you can redistribute it and/or modify it
 *  under the terms of the GNU General Public License version 2 as published
 *  by the Free Software Foundation.
 */

#include <linux/module.h>
#include <linux/ioport.h>
#include <linux/init.h>
#include <linux/console.h>
#include <linux/sysrq.h>
#include <linux/delay.h>
#include <linux/platform_device.h>
#include <linux/tty.h>
#include <linux/tty_flip.h>
#include <linux/serial_core.h>
#include <linux/serial.h>
#include <linux/slab.h>
#include <linux/io.h>
#include <linux/irq.h>
#include <linux/clk.h>

#include <asm/div64.h>

#include <asm/mach-ath79/ar933x_uart.h>

#define DRIVER_NAME "ar933x-uart"

#define AR933X_UART_MAX_SCALE	0xff
#define AR933X_UART_MAX_STEP	0xffff

#define AR933X_UART_MIN_BAUD	300
#define AR933X_UART_MAX_BAUD	3000000

#define AR933X_DUMMY_STATUS_RD	0x01

static struct uart_driver ar933x_uart_driver;

struct ar933x_uart_port {
	struct uart_port	port;
	unsigned int		ier;	/* shadow Interrupt Enable Register */
	unsigned int		min_baud;
	unsigned int		max_baud;
	struct clk		*clk;
};

static inline bool ar933x_uart_console_enabled(void)
{
	return config_enabled(CONFIG_SERIAL_AR933X_CONSOLE);
}

static inline unsigned int ar933x_uart_read(struct ar933x_uart_port *up,
					    int offset)
{
	return readl(up->port.membase + offset);
}

static inline void ar933x_uart_write(struct ar933x_uart_port *up,
				     int offset, unsigned int value)
{
	writel(value, up->port.membase + offset);
}

static inline void ar933x_uart_rmw(struct ar933x_uart_port *up,
				  unsigned int offset,
				  unsigned int mask,
				  unsigned int val)
{
	unsigned int t;

	t = ar933x_uart_read(up, offset);
	t &= ~mask;
	t |= val;
	ar933x_uart_write(up, offset, t);
}

static inline void ar933x_uart_rmw_set(struct ar933x_uart_port *up,
				       unsigned int offset,
				       unsigned int val)
{
	ar933x_uart_rmw(up, offset, 0, val);
}

static inline void ar933x_uart_rmw_clear(struct ar933x_uart_port *up,
					 unsigned int offset,
					 unsigned int val)
{
	ar933x_uart_rmw(up, offset, val, 0);
}

static inline void ar933x_uart_start_tx_interrupt(struct ar933x_uart_port *up)
{
	up->ier |= AR933X_UART_INT_TX_EMPTY;
	ar933x_uart_write(up, AR933X_UART_INT_EN_REG, up->ier);
}

static inline void ar933x_uart_stop_tx_interrupt(struct ar933x_uart_port *up)
{
	up->ier &= ~AR933X_UART_INT_TX_EMPTY;
	ar933x_uart_write(up, AR933X_UART_INT_EN_REG, up->ier);
}

static inline void ar933x_uart_putc(struct ar933x_uart_port *up, int ch)
{
	unsigned int rdata;

	rdata = ch & AR933X_UART_DATA_TX_RX_MASK;
	rdata |= AR933X_UART_DATA_TX_CSR;
	ar933x_uart_write(up, AR933X_UART_DATA_REG, rdata);
}

static unsigned int ar933x_uart_tx_empty(struct uart_port *port)
{
	struct ar933x_uart_port *up = (struct ar933x_uart_port *) port;
	unsigned long flags;
	unsigned int rdata;

	spin_lock_irqsave(&up->port.lock, flags);
	rdata = ar933x_uart_read(up, AR933X_UART_DATA_REG);
	spin_unlock_irqrestore(&up->port.lock, flags);

	return (rdata & AR933X_UART_DATA_TX_CSR) ? 0 : TIOCSER_TEMT;
}

static unsigned int ar933x_uart_get_mctrl(struct uart_port *port)
{
	return TIOCM_CAR;
}

static void ar933x_uart_set_mctrl(struct uart_port *port, unsigned int mctrl)
{
}

static void ar933x_uart_start_tx(struct uart_port *port)
{
	struct ar933x_uart_port *up = (struct ar933x_uart_port *) port;

	ar933x_uart_start_tx_interrupt(up);
}

static void ar933x_uart_stop_tx(struct uart_port *port)
{
	struct ar933x_uart_port *up = (struct ar933x_uart_port *) port;

	ar933x_uart_stop_tx_interrupt(up);
}

static void ar933x_uart_stop_rx(struct uart_port *port)
{
	struct ar933x_uart_port *up = (struct ar933x_uart_port *) port;

	up->ier &= ~AR933X_UART_INT_RX_VALID;
	ar933x_uart_write(up, AR933X_UART_INT_EN_REG, up->ier);
}

static void ar933x_uart_break_ctl(struct uart_port *port, int break_state)
{
	struct ar933x_uart_port *up = (struct ar933x_uart_port *) port;
	unsigned long flags;

	spin_lock_irqsave(&up->port.lock, flags);
	if (break_state == -1)
		ar933x_uart_rmw_set(up, AR933X_UART_CS_REG,
				    AR933X_UART_CS_TX_BREAK);
	else
		ar933x_uart_rmw_clear(up, AR933X_UART_CS_REG,
				      AR933X_UART_CS_TX_BREAK);
	spin_unlock_irqrestore(&up->port.lock, flags);
}

static void ar933x_uart_enable_ms(struct uart_port *port)
{
}

/*
 * baudrate = (clk / (scale + 1)) * (step * (1 / 2^17))
 */
static unsigned long ar933x_uart_get_baud(unsigned int clk,
					  unsigned int scale,
					  unsigned int step)
{
	u64 t;
	u32 div;

	div = (2 << 16) * (scale + 1);
	t = clk;
	t *= step;
	t += (div / 2);
	do_div(t, div);

	return t;
}

static void ar933x_uart_get_scale_step(unsigned int clk,
				       unsigned int baud,
				       unsigned int *scale,
				       unsigned int *step)
{
	unsigned int tscale;
	long min_diff;

	*scale = 0;
	*step = 0;

	min_diff = baud;
	for (tscale = 0; tscale < AR933X_UART_MAX_SCALE; tscale++) {
		u64 tstep;
		int diff;

		tstep = baud * (tscale + 1);
		tstep *= (2 << 16);
		do_div(tstep, clk);

		if (tstep > AR933X_UART_MAX_STEP)
			break;

		diff = abs(ar933x_uart_get_baud(clk, tscale, tstep) - baud);
		if (diff < min_diff) {
			min_diff = diff;
			*scale = tscale;
			*step = tstep;
		}
	}
}

static void ar933x_uart_set_termios(struct uart_port *port,
				    struct ktermios *new,
				    struct ktermios *old)
{
	struct ar933x_uart_port *up = (struct ar933x_uart_port *) port;
	unsigned int cs;
	unsigned long flags;
	unsigned int baud, scale, step;

	/* Only CS8 is supported */
	new->c_cflag &= ~CSIZE;
	new->c_cflag |= CS8;

	/* Only one stop bit is supported */
	new->c_cflag &= ~CSTOPB;

	cs = 0;
	if (new->c_cflag & PARENB) {
		if (!(new->c_cflag & PARODD))
			cs |= AR933X_UART_CS_PARITY_EVEN;
		else
			cs |= AR933X_UART_CS_PARITY_ODD;
	} else {
		cs |= AR933X_UART_CS_PARITY_NONE;
	}

	/* Mark/space parity is not supported */
	new->c_cflag &= ~CMSPAR;

	baud = uart_get_baud_rate(port, new, old, up->min_baud, up->max_baud);
	ar933x_uart_get_scale_step(port->uartclk, baud, &scale, &step);

	/*
	 * Ok, we're now changing the port state. Do it with
	 * interrupts disabled.
	 */
	spin_lock_irqsave(&up->port.lock, flags);

	/* disable the UART */
	ar933x_uart_rmw_clear(up, AR933X_UART_CS_REG,
		      AR933X_UART_CS_IF_MODE_M << AR933X_UART_CS_IF_MODE_S);

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

	up->port.ignore_status_mask = 0;

	/* ignore all characters if CREAD is not set */
	if ((new->c_cflag & CREAD) == 0)
		up->port.ignore_status_mask |= AR933X_DUMMY_STATUS_RD;

	ar933x_uart_write(up, AR933X_UART_CLOCK_REG,
			  scale << AR933X_UART_CLOCK_SCALE_S | step);

	/* setup configuration register */
	ar933x_uart_rmw(up, AR933X_UART_CS_REG, AR933X_UART_CS_PARITY_M, cs);

	/* enable host interrupt */
	ar933x_uart_rmw_set(up, AR933X_UART_CS_REG,
			    AR933X_UART_CS_HOST_INT_EN);

	/* reenable the UART */
	ar933x_uart_rmw(up, AR933X_UART_CS_REG,
			AR933X_UART_CS_IF_MODE_M << AR933X_UART_CS_IF_MODE_S,
			AR933X_UART_CS_IF_MODE_DCE << AR933X_UART_CS_IF_MODE_S);

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

	if (tty_termios_baud_rate(new))
		tty_termios_encode_baud_rate(new, baud, baud);
}

static void ar933x_uart_rx_chars(struct ar933x_uart_port *up)
{
	struct tty_port *port = &up->port.state->port;
	int max_count = 256;

	do {
		unsigned int rdata;
		unsigned char ch;

		rdata = ar933x_uart_read(up, AR933X_UART_DATA_REG);
		if ((rdata & AR933X_UART_DATA_RX_CSR) == 0)
			break;

		/* remove the character from the FIFO */
		ar933x_uart_write(up, AR933X_UART_DATA_REG,
				  AR933X_UART_DATA_RX_CSR);

		up->port.icount.rx++;
		ch = rdata & AR933X_UART_DATA_TX_RX_MASK;

		if (uart_handle_sysrq_char(&up->port, ch))
			continue;

		if ((up->port.ignore_status_mask & AR933X_DUMMY_STATUS_RD) == 0)
			tty_insert_flip_char(port, ch, TTY_NORMAL);
	} while (max_count-- > 0);

	spin_unlock(&up->port.lock);
	tty_flip_buffer_push(port);
	spin_lock(&up->port.lock);
}

static void ar933x_uart_tx_chars(struct ar933x_uart_port *up)
{
	struct circ_buf *xmit = &up->port.state->xmit;
	int count;

	if (uart_tx_stopped(&up->port))
		return;

	count = up->port.fifosize;
	do {
		unsigned int rdata;

		rdata = ar933x_uart_read(up, AR933X_UART_DATA_REG);
		if ((rdata & AR933X_UART_DATA_TX_CSR) == 0)
			break;

		if (up->port.x_char) {
			ar933x_uart_putc(up, up->port.x_char);
			up->port.icount.tx++;
			up->port.x_char = 0;
			continue;
		}

		if (uart_circ_empty(xmit))
			break;

		ar933x_uart_putc(up, xmit->buf[xmit->tail]);

		xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
		up->port.icount.tx++;
	} while (--count > 0);

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

	if (!uart_circ_empty(xmit))
		ar933x_uart_start_tx_interrupt(up);
}

static irqreturn_t ar933x_uart_interrupt(int irq, void *dev_id)
{
	struct ar933x_uart_port *up = dev_id;
	unsigned int status;

	status = ar933x_uart_read(up, AR933X_UART_CS_REG);
	if ((status & AR933X_UART_CS_HOST_INT) == 0)
		return IRQ_NONE;

	spin_lock(&up->port.lock);

	status = ar933x_uart_read(up, AR933X_UART_INT_REG);
	status &= ar933x_uart_read(up, AR933X_UART_INT_EN_REG);

	if (status & AR933X_UART_INT_RX_VALID) {
		ar933x_uart_write(up, AR933X_UART_INT_REG,
				  AR933X_UART_INT_RX_VALID);
		ar933x_uart_rx_chars(up);
	}

	if (status & AR933X_UART_INT_TX_EMPTY) {
		ar933x_uart_write(up, AR933X_UART_INT_REG,
				  AR933X_UART_INT_TX_EMPTY);
		ar933x_uart_stop_tx_interrupt(up);
		ar933x_uart_tx_chars(up);
	}

	spin_unlock(&up->port.lock);

	return IRQ_HANDLED;
}

static int ar933x_uart_startup(struct uart_port *port)
{
	struct ar933x_uart_port *up = (struct ar933x_uart_port *) port;
	unsigned long flags;
	int ret;

	ret = request_irq(up->port.irq, ar933x_uart_interrupt,
			  up->port.irqflags, dev_name(up->port.dev), up);
	if (ret)
		return ret;

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

	/* Enable HOST interrupts */
	ar933x_uart_rmw_set(up, AR933X_UART_CS_REG,
			    AR933X_UART_CS_HOST_INT_EN);

	/* Enable RX interrupts */
	up->ier = AR933X_UART_INT_RX_VALID;
	ar933x_uart_write(up, AR933X_UART_INT_EN_REG, up->ier);

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

	return 0;
}

static void ar933x_uart_shutdown(struct uart_port *port)
{
	struct ar933x_uart_port *up = (struct ar933x_uart_port *) port;

	/* Disable all interrupts */
	up->ier = 0;
	ar933x_uart_write(up, AR933X_UART_INT_EN_REG, up->ier);

	/* Disable break condition */
	ar933x_uart_rmw_clear(up, AR933X_UART_CS_REG,
			      AR933X_UART_CS_TX_BREAK);

	free_irq(up->port.irq, up);
}

static const char *ar933x_uart_type(struct uart_port *port)
{
	return (port->type == PORT_AR933X) ? "AR933X UART" : NULL;
}

static void ar933x_uart_release_port(struct uart_port *port)
{
	/* Nothing to release ... */
}

static int ar933x_uart_request_port(struct uart_port *port)
{
	/* UARTs always present */
	return 0;
}

static void ar933x_uart_config_port(struct uart_port *port, int flags)
{
	if (flags & UART_CONFIG_TYPE)
		port->type = PORT_AR933X;
}

static int ar933x_uart_verify_port(struct uart_port *port,
				   struct serial_struct *ser)
{
	struct ar933x_uart_port *up = (struct ar933x_uart_port *) port;

	if (ser->type != PORT_UNKNOWN &&
	    ser->type != PORT_AR933X)
		return -EINVAL;

	if (ser->irq < 0 || ser->irq >= NR_IRQS)
		return -EINVAL;

	if (ser->baud_base < up->min_baud ||
	    ser->baud_base > up->max_baud)
		return -EINVAL;

	return 0;
}

static struct uart_ops ar933x_uart_ops = {
	.tx_empty	= ar933x_uart_tx_empty,
	.set_mctrl	= ar933x_uart_set_mctrl,
	.get_mctrl	= ar933x_uart_get_mctrl,
	.stop_tx	= ar933x_uart_stop_tx,
	.start_tx	= ar933x_uart_start_tx,
	.stop_rx	= ar933x_uart_stop_rx,
	.enable_ms	= ar933x_uart_enable_ms,
	.break_ctl	= ar933x_uart_break_ctl,
	.startup	= ar933x_uart_startup,
	.shutdown	= ar933x_uart_shutdown,
	.set_termios	= ar933x_uart_set_termios,
	.type		= ar933x_uart_type,
	.release_port	= ar933x_uart_release_port,
	.request_port	= ar933x_uart_request_port,
	.config_port	= ar933x_uart_config_port,
	.verify_port	= ar933x_uart_verify_port,
};

static struct ar933x_uart_port *
ar933x_console_ports[CONFIG_SERIAL_AR933X_NR_UARTS];

static void ar933x_uart_wait_xmitr(struct ar933x_uart_port *up)
{
	unsigned int status;
	unsigned int timeout = 60000;

	/* Wait up to 60ms for the character(s) to be sent. */
	do {
		status = ar933x_uart_read(up, AR933X_UART_DATA_REG);
		if (--timeout == 0)
			break;
		udelay(1);
	} while ((status & AR933X_UART_DATA_TX_CSR) == 0);
}

static void ar933x_uart_console_putchar(struct uart_port *port, int ch)
{
	struct ar933x_uart_port *up = (struct ar933x_uart_port *) port;

	ar933x_uart_wait_xmitr(up);
	ar933x_uart_putc(up, ch);
}

static void ar933x_uart_console_write(struct console *co, const char *s,
				      unsigned int count)
{
	struct ar933x_uart_port *up = ar933x_console_ports[co->index];
	unsigned long flags;
	unsigned int int_en;
	int locked = 1;

	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);

	/*
	 * First save the IER then disable the interrupts
	 */
	int_en = ar933x_uart_read(up, AR933X_UART_INT_EN_REG);
	ar933x_uart_write(up, AR933X_UART_INT_EN_REG, 0);

	uart_console_write(&up->port, s, count, ar933x_uart_console_putchar);

	/*
	 * Finally, wait for transmitter to become empty
	 * and restore the IER
	 */
	ar933x_uart_wait_xmitr(up);
	ar933x_uart_write(up, AR933X_UART_INT_EN_REG, int_en);

	ar933x_uart_write(up, AR933X_UART_INT_REG, AR933X_UART_INT_ALLINTS);

	if (locked)
		spin_unlock(&up->port.lock);

	local_irq_restore(flags);
}

static int ar933x_uart_console_setup(struct console *co, char *options)
{
	struct ar933x_uart_port *up;
	int baud = 115200;
	int bits = 8;
	int parity = 'n';
	int flow = 'n';

	if (co->index < 0 || co->index >= CONFIG_SERIAL_AR933X_NR_UARTS)
		return -EINVAL;

	up = ar933x_console_ports[co->index];
	if (!up)
		return -ENODEV;

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

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

static struct console ar933x_uart_console = {
	.name		= "ttyATH",
	.write		= ar933x_uart_console_write,
	.device		= uart_console_device,
	.setup		= ar933x_uart_console_setup,
	.flags		= CON_PRINTBUFFER,
	.index		= -1,
	.data		= &ar933x_uart_driver,
};

static void ar933x_uart_add_console_port(struct ar933x_uart_port *up)
{
	if (!ar933x_uart_console_enabled())
		return;

	ar933x_console_ports[up->port.line] = up;
}

static struct uart_driver ar933x_uart_driver = {
	.owner		= THIS_MODULE,
	.driver_name	= DRIVER_NAME,
	.dev_name	= "ttyATH",
	.nr		= CONFIG_SERIAL_AR933X_NR_UARTS,
	.cons		= NULL, /* filled in runtime */
};

static int ar933x_uart_probe(struct platform_device *pdev)
{
	struct ar933x_uart_port *up;
	struct uart_port *port;
	struct resource *mem_res;
	struct resource *irq_res;
	unsigned int baud;
	int id;
	int ret;

	id = pdev->id;
	if (id == -1)
		id = 0;

	if (id > CONFIG_SERIAL_AR933X_NR_UARTS)
		return -EINVAL;

	irq_res = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
	if (!irq_res) {
		dev_err(&pdev->dev, "no IRQ resource\n");
		return -EINVAL;
	}

	up = devm_kzalloc(&pdev->dev, sizeof(struct ar933x_uart_port),
			  GFP_KERNEL);
	if (!up)
		return -ENOMEM;

	up->clk = devm_clk_get(&pdev->dev, "uart");
	if (IS_ERR(up->clk)) {
		dev_err(&pdev->dev, "unable to get UART clock\n");
		return PTR_ERR(up->clk);
	}

	port = &up->port;

	mem_res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
	port->membase = devm_ioremap_resource(&pdev->dev, mem_res);
	if (IS_ERR(port->membase))
		return PTR_ERR(port->membase);

	ret = clk_prepare_enable(up->clk);
	if (ret)
		return ret;

	port->uartclk = clk_get_rate(up->clk);
	if (!port->uartclk) {
		ret = -EINVAL;
		goto err_disable_clk;
	}

	port->mapbase = mem_res->start;
	port->line = id;
	port->irq = irq_res->start;
	port->dev = &pdev->dev;
	port->type = PORT_AR933X;
	port->iotype = UPIO_MEM32;

	port->regshift = 2;
	port->fifosize = AR933X_UART_FIFO_SIZE;
	port->ops = &ar933x_uart_ops;

	baud = ar933x_uart_get_baud(port->uartclk, AR933X_UART_MAX_SCALE, 1);
	up->min_baud = max_t(unsigned int, baud, AR933X_UART_MIN_BAUD);

	baud = ar933x_uart_get_baud(port->uartclk, 0, AR933X_UART_MAX_STEP);
	up->max_baud = min_t(unsigned int, baud, AR933X_UART_MAX_BAUD);

	ar933x_uart_add_console_port(up);

	ret = uart_add_one_port(&ar933x_uart_driver, &up->port);
	if (ret)
		goto err_disable_clk;

	platform_set_drvdata(pdev, up);
	return 0;

err_disable_clk:
	clk_disable_unprepare(up->clk);
	return ret;
}

static int ar933x_uart_remove(struct platform_device *pdev)
{
	struct ar933x_uart_port *up;

	up = platform_get_drvdata(pdev);

	if (up) {
		uart_remove_one_port(&ar933x_uart_driver, &up->port);
		clk_disable_unprepare(up->clk);
	}

	return 0;
}

static struct platform_driver ar933x_uart_platform_driver = {
	.probe		= ar933x_uart_probe,
	.remove		= ar933x_uart_remove,
	.driver		= {
		.name		= DRIVER_NAME,
		.owner		= THIS_MODULE,
	},
};

static int __init ar933x_uart_init(void)
{
	int ret;

	if (ar933x_uart_console_enabled())
		ar933x_uart_driver.cons = &ar933x_uart_console;

	ret = uart_register_driver(&ar933x_uart_driver);
	if (ret)
		goto err_out;

	ret = platform_driver_register(&ar933x_uart_platform_driver);
	if (ret)
		goto err_unregister_uart_driver;

	return 0;

err_unregister_uart_driver:
	uart_unregister_driver(&ar933x_uart_driver);
err_out:
	return ret;
}

static void __exit ar933x_uart_exit(void)
{
	platform_driver_unregister(&ar933x_uart_platform_driver);
	uart_unregister_driver(&ar933x_uart_driver);
}

module_init(ar933x_uart_init);
module_exit(ar933x_uart_exit);

MODULE_DESCRIPTION("Atheros AR933X UART driver");
MODULE_AUTHOR("Gabor Juhos <juhosg@openwrt.org>");
MODULE_LICENSE("GPL v2");
MODULE_ALIAS("platform:" DRIVER_NAME);
Commit	Line	Data
d57f341b GJ	1	/*
	2	* Atheros AR933X SoC built-in UART driver
	3	*
	4	* Copyright (C) 2011 Gabor Juhos <juhosg@openwrt.org>
	5	*
	6	* Based on drivers/char/serial.c, by Linus Torvalds, Theodore Ts'o.
	7	*
	8	* This program is free software; you can redistribute it and/or modify it
	9	* under the terms of the GNU General Public License version 2 as published
	10	* by the Free Software Foundation.
	11	*/
	12
	13	#include <linux/module.h>
	14	#include <linux/ioport.h>
	15	#include <linux/init.h>
	16	#include <linux/console.h>
	17	#include <linux/sysrq.h>
	18	#include <linux/delay.h>
	19	#include <linux/platform_device.h>
	20	#include <linux/tty.h>
	21	#include <linux/tty_flip.h>
	22	#include <linux/serial_core.h>
	23	#include <linux/serial.h>
	24	#include <linux/slab.h>
	25	#include <linux/io.h>
	26	#include <linux/irq.h>
15ef17f6	27	#include <linux/clk.h>
d57f341b	28
2dff8ad9 GJ	29	#include <asm/div64.h>
2dff8ad9 GJ	30
d57f341b	31	#include <asm/mach-ath79/ar933x_uart.h>
d57f341b GJ	32
	33	#define DRIVER_NAME "ar933x-uart"
	34
2dff8ad9 GJ	35	#define AR933X_UART_MAX_SCALE 0xff
	36	#define AR933X_UART_MAX_STEP 0xffff
	37
	38	#define AR933X_UART_MIN_BAUD 300
	39	#define AR933X_UART_MAX_BAUD 3000000
	40
d57f341b GJ	41	#define AR933X_DUMMY_STATUS_RD 0x01
	42
	43	static struct uart_driver ar933x_uart_driver;
	44
	45	struct ar933x_uart_port {
	46	struct uart_port port;
	47	unsigned int ier; /* shadow Interrupt Enable Register */
2dff8ad9 GJ	48	unsigned int min_baud;
2dff8ad9 GJ	49	unsigned int max_baud;
15ef17f6	50	struct clk *clk;
d57f341b GJ	51	};
d57f341b GJ	52
12415535 GJ	53	static inline bool ar933x_uart_console_enabled(void)
	54	{
	55	return config_enabled(CONFIG_SERIAL_AR933X_CONSOLE);
	56	}
	57
d57f341b GJ	58	static inline unsigned int ar933x_uart_read(struct ar933x_uart_port *up,
	59	int offset)
	60	{
	61	return readl(up->port.membase + offset);
	62	}
	63
	64	static inline void ar933x_uart_write(struct ar933x_uart_port *up,
	65	int offset, unsigned int value)
	66	{
	67	writel(value, up->port.membase + offset);
	68	}
	69
	70	static inline void ar933x_uart_rmw(struct ar933x_uart_port *up,
	71	unsigned int offset,
	72	unsigned int mask,
	73	unsigned int val)
	74	{
	75	unsigned int t;
	76
	77	t = ar933x_uart_read(up, offset);
	78	t &= ~mask;
	79	t \|= val;
	80	ar933x_uart_write(up, offset, t);
	81	}
	82
	83	static inline void ar933x_uart_rmw_set(struct ar933x_uart_port *up,
	84	unsigned int offset,
	85	unsigned int val)
	86	{
	87	ar933x_uart_rmw(up, offset, 0, val);
	88	}
	89
	90	static inline void ar933x_uart_rmw_clear(struct ar933x_uart_port *up,
	91	unsigned int offset,
	92	unsigned int val)
	93	{
	94	ar933x_uart_rmw(up, offset, val, 0);
	95	}
	96
	97	static inline void ar933x_uart_start_tx_interrupt(struct ar933x_uart_port *up)
	98	{
	99	up->ier \|= AR933X_UART_INT_TX_EMPTY;
	100	ar933x_uart_write(up, AR933X_UART_INT_EN_REG, up->ier);
	101	}
	102
	103	static inline void ar933x_uart_stop_tx_interrupt(struct ar933x_uart_port *up)
	104	{
	105	up->ier &= ~AR933X_UART_INT_TX_EMPTY;
	106	ar933x_uart_write(up, AR933X_UART_INT_EN_REG, up->ier);
	107	}
	108
	109	static inline void ar933x_uart_putc(struct ar933x_uart_port *up, int ch)
	110	{
	111	unsigned int rdata;
	112
	113	rdata = ch & AR933X_UART_DATA_TX_RX_MASK;
	114	rdata \|= AR933X_UART_DATA_TX_CSR;
	115	ar933x_uart_write(up, AR933X_UART_DATA_REG, rdata);
	116	}
	117
	118	static unsigned int ar933x_uart_tx_empty(struct uart_port *port)
	119	{
	120	struct ar933x_uart_port up = (struct ar933x_uart_port ) port;
	121	unsigned long flags;
122	unsigned int rdata;
123
124	spin_lock_irqsave(&up->port.lock, flags);
125	rdata = ar933x_uart_read(up, AR933X_UART_DATA_REG);
126	spin_unlock_irqrestore(&up->port.lock, flags);
127
128	return (rdata & AR933X_UART_DATA_TX_CSR) ? 0 : TIOCSER_TEMT;
129	}
130
131	static unsigned int ar933x_uart_get_mctrl(struct uart_port *port)
132	{
133	return TIOCM_CAR;
134	}
135
136	static void ar933x_uart_set_mctrl(struct uart_port *port, unsigned int mctrl)
137	{
138	}
139
140	static void ar933x_uart_start_tx(struct uart_port *port)
141	{
142	struct ar933x_uart_port up = (struct ar933x_uart_port ) port;
143
144	ar933x_uart_start_tx_interrupt(up);
145	}
146
147	static void ar933x_uart_stop_tx(struct uart_port *port)
148	{
149	struct ar933x_uart_port up = (struct ar933x_uart_port ) port;
150
151	ar933x_uart_stop_tx_interrupt(up);
152	}
153
154	static void ar933x_uart_stop_rx(struct uart_port *port)
155	{
156	struct ar933x_uart_port up = (struct ar933x_uart_port ) port;
157
158	up->ier &= ~AR933X_UART_INT_RX_VALID;
159	ar933x_uart_write(up, AR933X_UART_INT_EN_REG, up->ier);
160	}
161
162	static void ar933x_uart_break_ctl(struct uart_port *port, int break_state)
163	{
164	struct ar933x_uart_port up = (struct ar933x_uart_port ) port;
165	unsigned long flags;
166
167	spin_lock_irqsave(&up->port.lock, flags);
168	if (break_state == -1)
169	ar933x_uart_rmw_set(up, AR933X_UART_CS_REG,
170	AR933X_UART_CS_TX_BREAK);
171	else
172	ar933x_uart_rmw_clear(up, AR933X_UART_CS_REG,
173	AR933X_UART_CS_TX_BREAK);
174	spin_unlock_irqrestore(&up->port.lock, flags);
175	}
176
177	static void ar933x_uart_enable_ms(struct uart_port *port)
178	{
179	}
180
2dff8ad9 GJ	181	/*
	182	* baudrate = (clk / (scale + 1)) * (step * (1 / 2^17))
	183	*/
	184	static unsigned long ar933x_uart_get_baud(unsigned int clk,
	185	unsigned int scale,
	186	unsigned int step)
	187	{
	188	u64 t;
	189	u32 div;
	190
	191	div = (2 << 16) * (scale + 1);
	192	t = clk;
	193	t *= step;
	194	t += (div / 2);
	195	do_div(t, div);
	196
	197	return t;
	198	}
	199
	200	static void ar933x_uart_get_scale_step(unsigned int clk,
	201	unsigned int baud,
	202	unsigned int *scale,
	203	unsigned int *step)
	204	{
	205	unsigned int tscale;
	206	long min_diff;
	207
	208	*scale = 0;
	209	*step = 0;
	210
	211	min_diff = baud;
	212	for (tscale = 0; tscale < AR933X_UART_MAX_SCALE; tscale++) {
	213	u64 tstep;
	214	int diff;
	215
	216	tstep = baud * (tscale + 1);
	217	tstep *= (2 << 16);
	218	do_div(tstep, clk);
	219
	220	if (tstep > AR933X_UART_MAX_STEP)
	221	break;
	222
	223	diff = abs(ar933x_uart_get_baud(clk, tscale, tstep) - baud);
	224	if (diff < min_diff) {
	225	min_diff = diff;
	226	*scale = tscale;
	227	*step = tstep;
	228	}
	229	}
	230	}
	231
d57f341b GJ	232	static void ar933x_uart_set_termios(struct uart_port *port,
	233	struct ktermios *new,
	234	struct ktermios *old)
	235	{
	236	struct ar933x_uart_port up = (struct ar933x_uart_port ) port;
	237	unsigned int cs;
	238	unsigned long flags;
2dff8ad9	239	unsigned int baud, scale, step;
d57f341b GJ	240
	241	/* Only CS8 is supported */
	242	new->c_cflag &= ~CSIZE;
	243	new->c_cflag \|= CS8;
	244
	245	/* Only one stop bit is supported */
	246	new->c_cflag &= ~CSTOPB;
	247
	248	cs = 0;
	249	if (new->c_cflag & PARENB) {
	250	if (!(new->c_cflag & PARODD))
	251	cs \|= AR933X_UART_CS_PARITY_EVEN;
	252	else
	253	cs \|= AR933X_UART_CS_PARITY_ODD;
	254	} else {
	255	cs \|= AR933X_UART_CS_PARITY_NONE;
	256	}
	257
	258	/* Mark/space parity is not supported */
	259	new->c_cflag &= ~CMSPAR;
	260
2dff8ad9 GJ	261	baud = uart_get_baud_rate(port, new, old, up->min_baud, up->max_baud);
2dff8ad9 GJ	262	ar933x_uart_get_scale_step(port->uartclk, baud, &scale, &step);
d57f341b GJ	263
	264	/*
	265	* Ok, we're now changing the port state. Do it with
	266	* interrupts disabled.
	267	*/
	268	spin_lock_irqsave(&up->port.lock, flags);
	269
2dff8ad9 GJ	270	/* disable the UART */
	271	ar933x_uart_rmw_clear(up, AR933X_UART_CS_REG,
	272	AR933X_UART_CS_IF_MODE_M << AR933X_UART_CS_IF_MODE_S);
	273
d57f341b GJ	274	/* Update the per-port timeout. */
	275	uart_update_timeout(port, new->c_cflag, baud);
	276
	277	up->port.ignore_status_mask = 0;
	278
	279	/* ignore all characters if CREAD is not set */
	280	if ((new->c_cflag & CREAD) == 0)
	281	up->port.ignore_status_mask \|= AR933X_DUMMY_STATUS_RD;
	282
	283	ar933x_uart_write(up, AR933X_UART_CLOCK_REG,
2dff8ad9	284	scale << AR933X_UART_CLOCK_SCALE_S \| step);
d57f341b GJ	285
	286	/* setup configuration register */
	287	ar933x_uart_rmw(up, AR933X_UART_CS_REG, AR933X_UART_CS_PARITY_M, cs);
	288
	289	/* enable host interrupt */
	290	ar933x_uart_rmw_set(up, AR933X_UART_CS_REG,
	291	AR933X_UART_CS_HOST_INT_EN);
	292
2dff8ad9 GJ	293	/* reenable the UART */
	294	ar933x_uart_rmw(up, AR933X_UART_CS_REG,
	295	AR933X_UART_CS_IF_MODE_M << AR933X_UART_CS_IF_MODE_S,
	296	AR933X_UART_CS_IF_MODE_DCE << AR933X_UART_CS_IF_MODE_S);
	297
d57f341b GJ	298	spin_unlock_irqrestore(&up->port.lock, flags);
	299
	300	if (tty_termios_baud_rate(new))
	301	tty_termios_encode_baud_rate(new, baud, baud);
	302	}
	303
	304	static void ar933x_uart_rx_chars(struct ar933x_uart_port *up)
	305	{
92a19f9c	306	struct tty_port *port = &up->port.state->port;
d57f341b GJ	307	int max_count = 256;
d57f341b GJ	308
d57f341b GJ	309	do {
	310	unsigned int rdata;
	311	unsigned char ch;
	312
	313	rdata = ar933x_uart_read(up, AR933X_UART_DATA_REG);
	314	if ((rdata & AR933X_UART_DATA_RX_CSR) == 0)
	315	break;
	316
	317	/* remove the character from the FIFO */
	318	ar933x_uart_write(up, AR933X_UART_DATA_REG,
	319	AR933X_UART_DATA_RX_CSR);
	320
d57f341b GJ	321	up->port.icount.rx++;
	322	ch = rdata & AR933X_UART_DATA_TX_RX_MASK;
	323
	324	if (uart_handle_sysrq_char(&up->port, ch))
	325	continue;
	326
	327	if ((up->port.ignore_status_mask & AR933X_DUMMY_STATUS_RD) == 0)
92a19f9c	328	tty_insert_flip_char(port, ch, TTY_NORMAL);
d57f341b GJ	329	} while (max_count-- > 0);
d57f341b GJ	330
b16c8e3e	331	spin_unlock(&up->port.lock);
2e124b4a	332	tty_flip_buffer_push(port);
b16c8e3e	333	spin_lock(&up->port.lock);
d57f341b GJ	334	}
	335
	336	static void ar933x_uart_tx_chars(struct ar933x_uart_port *up)
	337	{
	338	struct circ_buf *xmit = &up->port.state->xmit;
	339	int count;
	340
	341	if (uart_tx_stopped(&up->port))
	342	return;
	343
	344	count = up->port.fifosize;
	345	do {
	346	unsigned int rdata;
	347
	348	rdata = ar933x_uart_read(up, AR933X_UART_DATA_REG);
	349	if ((rdata & AR933X_UART_DATA_TX_CSR) == 0)
	350	break;
	351
	352	if (up->port.x_char) {
	353	ar933x_uart_putc(up, up->port.x_char);
	354	up->port.icount.tx++;
	355	up->port.x_char = 0;
	356	continue;
	357	}
	358
	359	if (uart_circ_empty(xmit))
	360	break;
	361
	362	ar933x_uart_putc(up, xmit->buf[xmit->tail]);
	363
	364	xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
	365	up->port.icount.tx++;
	366	} while (--count > 0);
	367
	368	if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
	369	uart_write_wakeup(&up->port);
	370
	371	if (!uart_circ_empty(xmit))
	372	ar933x_uart_start_tx_interrupt(up);
	373	}
	374
	375	static irqreturn_t ar933x_uart_interrupt(int irq, void *dev_id)
	376	{
	377	struct ar933x_uart_port *up = dev_id;
	378	unsigned int status;
	379
	380	status = ar933x_uart_read(up, AR933X_UART_CS_REG);
	381	if ((status & AR933X_UART_CS_HOST_INT) == 0)
	382	return IRQ_NONE;
	383
	384	spin_lock(&up->port.lock);
	385
	386	status = ar933x_uart_read(up, AR933X_UART_INT_REG);
	387	status &= ar933x_uart_read(up, AR933X_UART_INT_EN_REG);
	388
	389	if (status & AR933X_UART_INT_RX_VALID) {
	390	ar933x_uart_write(up, AR933X_UART_INT_REG,
	391	AR933X_UART_INT_RX_VALID);
	392	ar933x_uart_rx_chars(up);
	393	}
	394
	395	if (status & AR933X_UART_INT_TX_EMPTY) {
	396	ar933x_uart_write(up, AR933X_UART_INT_REG,
	397	AR933X_UART_INT_TX_EMPTY);
398	ar933x_uart_stop_tx_interrupt(up);
399	ar933x_uart_tx_chars(up);
400	}
401
402	spin_unlock(&up->port.lock);
403
404	return IRQ_HANDLED;
405	}
406
407	static int ar933x_uart_startup(struct uart_port *port)
408	{
409	struct ar933x_uart_port up = (struct ar933x_uart_port ) port;
410	unsigned long flags;
411	int ret;
412
413	ret = request_irq(up->port.irq, ar933x_uart_interrupt,
414	up->port.irqflags, dev_name(up->port.dev), up);
415	if (ret)
416	return ret;
417
418	spin_lock_irqsave(&up->port.lock, flags);
419
420	/* Enable HOST interrupts */
421	ar933x_uart_rmw_set(up, AR933X_UART_CS_REG,
422	AR933X_UART_CS_HOST_INT_EN);
423
424	/* Enable RX interrupts */
425	up->ier = AR933X_UART_INT_RX_VALID;
426	ar933x_uart_write(up, AR933X_UART_INT_EN_REG, up->ier);
427
428	spin_unlock_irqrestore(&up->port.lock, flags);
429
430	return 0;
431	}
432
433	static void ar933x_uart_shutdown(struct uart_port *port)
434	{
435	struct ar933x_uart_port up = (struct ar933x_uart_port ) port;
436
437	/* Disable all interrupts */
438	up->ier = 0;
439	ar933x_uart_write(up, AR933X_UART_INT_EN_REG, up->ier);
440
441	/* Disable break condition */
442	ar933x_uart_rmw_clear(up, AR933X_UART_CS_REG,
443	AR933X_UART_CS_TX_BREAK);
444
445	free_irq(up->port.irq, up);
446	}
447
448	static const char ar933x_uart_type(struct uart_port port)
449	{
450	return (port->type == PORT_AR933X) ? "AR933X UART" : NULL;
451	}
452
453	static void ar933x_uart_release_port(struct uart_port *port)
454	{
455	/* Nothing to release ... */
456	}
457
458	static int ar933x_uart_request_port(struct uart_port *port)
459	{
460	/* UARTs always present */
461	return 0;
462	}
463
464	static void ar933x_uart_config_port(struct uart_port *port, int flags)
465	{
466	if (flags & UART_CONFIG_TYPE)
467	port->type = PORT_AR933X;
468	}
469
470	static int ar933x_uart_verify_port(struct uart_port *port,
471	struct serial_struct *ser)
472	{
2dff8ad9 GJ	473	struct ar933x_uart_port up = (struct ar933x_uart_port ) port;
2dff8ad9 GJ	474
d57f341b GJ	475	if (ser->type != PORT_UNKNOWN &&
	476	ser->type != PORT_AR933X)
	477	return -EINVAL;
	478
	479	if (ser->irq < 0 \|\| ser->irq >= NR_IRQS)
	480	return -EINVAL;
	481
2dff8ad9 GJ	482	if (ser->baud_base < up->min_baud \|\|
2dff8ad9 GJ	483	ser->baud_base > up->max_baud)
d57f341b GJ	484	return -EINVAL;
	485
	486	return 0;
	487	}
	488
	489	static struct uart_ops ar933x_uart_ops = {
	490	.tx_empty = ar933x_uart_tx_empty,
	491	.set_mctrl = ar933x_uart_set_mctrl,
	492	.get_mctrl = ar933x_uart_get_mctrl,
	493	.stop_tx = ar933x_uart_stop_tx,
	494	.start_tx = ar933x_uart_start_tx,
	495	.stop_rx = ar933x_uart_stop_rx,
	496	.enable_ms = ar933x_uart_enable_ms,
	497	.break_ctl = ar933x_uart_break_ctl,
	498	.startup = ar933x_uart_startup,
	499	.shutdown = ar933x_uart_shutdown,
	500	.set_termios = ar933x_uart_set_termios,
	501	.type = ar933x_uart_type,
	502	.release_port = ar933x_uart_release_port,
	503	.request_port = ar933x_uart_request_port,
	504	.config_port = ar933x_uart_config_port,
	505	.verify_port = ar933x_uart_verify_port,
	506	};
	507
d57f341b GJ	508	static struct ar933x_uart_port *
	509	ar933x_console_ports[CONFIG_SERIAL_AR933X_NR_UARTS];
	510
	511	static void ar933x_uart_wait_xmitr(struct ar933x_uart_port *up)
	512	{
	513	unsigned int status;
	514	unsigned int timeout = 60000;
	515
	516	/* Wait up to 60ms for the character(s) to be sent. */
	517	do {
	518	status = ar933x_uart_read(up, AR933X_UART_DATA_REG);
	519	if (--timeout == 0)
	520	break;
	521	udelay(1);
	522	} while ((status & AR933X_UART_DATA_TX_CSR) == 0);
	523	}
	524
	525	static void ar933x_uart_console_putchar(struct uart_port *port, int ch)
	526	{
	527	struct ar933x_uart_port up = (struct ar933x_uart_port ) port;
	528
	529	ar933x_uart_wait_xmitr(up);
	530	ar933x_uart_putc(up, ch);
	531	}
	532
	533	static void ar933x_uart_console_write(struct console co, const char s,
	534	unsigned int count)
	535	{
	536	struct ar933x_uart_port *up = ar933x_console_ports[co->index];
	537	unsigned long flags;
	538	unsigned int int_en;
	539	int locked = 1;
	540
	541	local_irq_save(flags);
	542
	543	if (up->port.sysrq)
	544	locked = 0;
	545	else if (oops_in_progress)
	546	locked = spin_trylock(&up->port.lock);
	547	else
	548	spin_lock(&up->port.lock);
	549
	550	/*
	551	* First save the IER then disable the interrupts
	552	*/
	553	int_en = ar933x_uart_read(up, AR933X_UART_INT_EN_REG);
	554	ar933x_uart_write(up, AR933X_UART_INT_EN_REG, 0);
	555
	556	uart_console_write(&up->port, s, count, ar933x_uart_console_putchar);
	557
	558	/*
	559	* Finally, wait for transmitter to become empty
	560	* and restore the IER
	561	*/
	562	ar933x_uart_wait_xmitr(up);
	563	ar933x_uart_write(up, AR933X_UART_INT_EN_REG, int_en);
	564
	565	ar933x_uart_write(up, AR933X_UART_INT_REG, AR933X_UART_INT_ALLINTS);
	566
	567	if (locked)
	568	spin_unlock(&up->port.lock);
	569
	570	local_irq_restore(flags);
	571	}
572
573	static int ar933x_uart_console_setup(struct console co, char options)
574	{
575	struct ar933x_uart_port *up;
576	int baud = 115200;
577	int bits = 8;
578	int parity = 'n';
579	int flow = 'n';
580
581	if (co->index < 0 \|\| co->index >= CONFIG_SERIAL_AR933X_NR_UARTS)
582	return -EINVAL;
583
584	up = ar933x_console_ports[co->index];
585	if (!up)
586	return -ENODEV;
587
588	if (options)
589	uart_parse_options(options, &baud, &parity, &bits, &flow);
590
591	return uart_set_options(&up->port, co, baud, parity, bits, flow);
592	}
593
594	static struct console ar933x_uart_console = {
595	.name = "ttyATH",
596	.write = ar933x_uart_console_write,
597	.device = uart_console_device,
598	.setup = ar933x_uart_console_setup,
599	.flags = CON_PRINTBUFFER,
600	.index = -1,
601	.data = &ar933x_uart_driver,
602	};
603
604	static void ar933x_uart_add_console_port(struct ar933x_uart_port *up)
605	{
12415535 GJ	606	if (!ar933x_uart_console_enabled())
	607	return;
	608
d57f341b GJ	609	ar933x_console_ports[up->port.line] = up;
	610	}
	611
d57f341b GJ	612	static struct uart_driver ar933x_uart_driver = {
	613	.owner = THIS_MODULE,
	614	.driver_name = DRIVER_NAME,
	615	.dev_name = "ttyATH",
	616	.nr = CONFIG_SERIAL_AR933X_NR_UARTS,
12415535	617	.cons = NULL, /* filled in runtime */
d57f341b GJ	618	};
d57f341b GJ	619
9671f099	620	static int ar933x_uart_probe(struct platform_device *pdev)
d57f341b	621	{
d57f341b GJ	622	struct ar933x_uart_port *up;
	623	struct uart_port *port;
	624	struct resource *mem_res;
	625	struct resource *irq_res;
2dff8ad9	626	unsigned int baud;
d57f341b GJ	627	int id;
	628	int ret;
	629
d57f341b GJ	630	id = pdev->id;
	631	if (id == -1)
	632	id = 0;
	633
	634	if (id > CONFIG_SERIAL_AR933X_NR_UARTS)
	635	return -EINVAL;
	636
d57f341b GJ	637	irq_res = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
	638	if (!irq_res) {
	639	dev_err(&pdev->dev, "no IRQ resource\n");
	640	return -EINVAL;
	641	}
	642
a324e4de GJ	643	up = devm_kzalloc(&pdev->dev, sizeof(struct ar933x_uart_port),
a324e4de GJ	644	GFP_KERNEL);
d57f341b GJ	645	if (!up)
	646	return -ENOMEM;
	647
15ef17f6 GJ	648	up->clk = devm_clk_get(&pdev->dev, "uart");
	649	if (IS_ERR(up->clk)) {
	650	dev_err(&pdev->dev, "unable to get UART clock\n");
	651	return PTR_ERR(up->clk);
	652	}
	653
d57f341b	654	port = &up->port;
d57f341b	655
071eb0ff	656	mem_res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
a324e4de GJ	657	port->membase = devm_ioremap_resource(&pdev->dev, mem_res);
	658	if (IS_ERR(port->membase))
	659	return PTR_ERR(port->membase);
d57f341b	660
15ef17f6 GJ	661	ret = clk_prepare_enable(up->clk);
	662	if (ret)
	663	return ret;
	664
	665	port->uartclk = clk_get_rate(up->clk);
	666	if (!port->uartclk) {
	667	ret = -EINVAL;
	668	goto err_disable_clk;
	669	}
	670
a324e4de	671	port->mapbase = mem_res->start;
d57f341b GJ	672	port->line = id;
	673	port->irq = irq_res->start;
	674	port->dev = &pdev->dev;
	675	port->type = PORT_AR933X;
	676	port->iotype = UPIO_MEM32;
d57f341b GJ	677
	678	port->regshift = 2;
	679	port->fifosize = AR933X_UART_FIFO_SIZE;
	680	port->ops = &ar933x_uart_ops;
	681
2dff8ad9 GJ	682	baud = ar933x_uart_get_baud(port->uartclk, AR933X_UART_MAX_SCALE, 1);
	683	up->min_baud = max_t(unsigned int, baud, AR933X_UART_MIN_BAUD);
	684
	685	baud = ar933x_uart_get_baud(port->uartclk, 0, AR933X_UART_MAX_STEP);
	686	up->max_baud = min_t(unsigned int, baud, AR933X_UART_MAX_BAUD);
	687
d57f341b GJ	688	ar933x_uart_add_console_port(up);
	689
	690	ret = uart_add_one_port(&ar933x_uart_driver, &up->port);
	691	if (ret)
15ef17f6	692	goto err_disable_clk;
d57f341b GJ	693
	694	platform_set_drvdata(pdev, up);
	695	return 0;
15ef17f6 GJ	696
	697	err_disable_clk:
	698	clk_disable_unprepare(up->clk);
	699	return ret;
d57f341b GJ	700	}
d57f341b GJ	701
ae8d8a14	702	static int ar933x_uart_remove(struct platform_device *pdev)
d57f341b GJ	703	{
	704	struct ar933x_uart_port *up;
	705
	706	up = platform_get_drvdata(pdev);
d57f341b	707
15ef17f6	708	if (up) {
d57f341b	709	uart_remove_one_port(&ar933x_uart_driver, &up->port);
15ef17f6 GJ	710	clk_disable_unprepare(up->clk);
15ef17f6 GJ	711	}
d57f341b GJ	712
	713	return 0;
	714	}
	715
	716	static struct platform_driver ar933x_uart_platform_driver = {
	717	.probe = ar933x_uart_probe,
2d47b716	718	.remove = ar933x_uart_remove,
d57f341b GJ	719	.driver = {
	720	.name = DRIVER_NAME,
	721	.owner = THIS_MODULE,
	722	},
	723	};
	724
	725	static int __init ar933x_uart_init(void)
	726	{
	727	int ret;
	728
12415535 GJ	729	if (ar933x_uart_console_enabled())
	730	ar933x_uart_driver.cons = &ar933x_uart_console;
	731
d57f341b GJ	732	ret = uart_register_driver(&ar933x_uart_driver);
	733	if (ret)
	734	goto err_out;
	735
	736	ret = platform_driver_register(&ar933x_uart_platform_driver);
	737	if (ret)
	738	goto err_unregister_uart_driver;
	739
	740	return 0;
	741
	742	err_unregister_uart_driver:
	743	uart_unregister_driver(&ar933x_uart_driver);
	744	err_out:
	745	return ret;
	746	}
	747
	748	static void __exit ar933x_uart_exit(void)
	749	{
	750	platform_driver_unregister(&ar933x_uart_platform_driver);
	751	uart_unregister_driver(&ar933x_uart_driver);
	752	}
	753
	754	module_init(ar933x_uart_init);
	755	module_exit(ar933x_uart_exit);
	756
	757	MODULE_DESCRIPTION("Atheros AR933X UART driver");
	758	MODULE_AUTHOR("Gabor Juhos <juhosg@openwrt.org>");
	759	MODULE_LICENSE("GPL v2");
	760	MODULE_ALIAS("platform:" DRIVER_NAME);