[net-next-2.6.git] / drivers / serial / altera_uart.c

/*
 * altera_uart.c -- Altera UART driver
 *
 * Based on mcf.c -- Freescale ColdFire UART driver
 *
 * (C) Copyright 2003-2007, Greg Ungerer <gerg@snapgear.com>
 * (C) Copyright 2008, Thomas Chou <thomas@wytron.com.tw>
 * (C) Copyright 2010, Tobias Klauser <tklauser@distanz.ch>
 *
 * 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.
 */

#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/interrupt.h>
#include <linux/module.h>
#include <linux/console.h>
#include <linux/tty.h>
#include <linux/tty_flip.h>
#include <linux/serial.h>
#include <linux/serial_core.h>
#include <linux/platform_device.h>
#include <linux/io.h>
#include <linux/altera_uart.h>

#define DRV_NAME "altera_uart"

/*
 * Altera UART register definitions according to the Nios UART datasheet:
 * http://www.altera.com/literature/ds/ds_nios_uart.pdf
 */

#define ALTERA_UART_SIZE		32

#define ALTERA_UART_RXDATA_REG		0
#define ALTERA_UART_TXDATA_REG		4
#define ALTERA_UART_STATUS_REG		8
#define ALTERA_UART_CONTROL_REG		12
#define ALTERA_UART_DIVISOR_REG		16
#define ALTERA_UART_EOP_REG		20

#define ALTERA_UART_STATUS_PE_MSK	0x0001	/* parity error */
#define ALTERA_UART_STATUS_FE_MSK	0x0002	/* framing error */
#define ALTERA_UART_STATUS_BRK_MSK	0x0004	/* break */
#define ALTERA_UART_STATUS_ROE_MSK	0x0008	/* RX overrun error */
#define ALTERA_UART_STATUS_TOE_MSK	0x0010	/* TX overrun error */
#define ALTERA_UART_STATUS_TMT_MSK	0x0020	/* TX shift register state */
#define ALTERA_UART_STATUS_TRDY_MSK	0x0040	/* TX ready */
#define ALTERA_UART_STATUS_RRDY_MSK	0x0080	/* RX ready */
#define ALTERA_UART_STATUS_E_MSK	0x0100	/* exception condition */
#define ALTERA_UART_STATUS_DCTS_MSK	0x0400	/* CTS logic-level change */
#define ALTERA_UART_STATUS_CTS_MSK	0x0800	/* CTS logic state */
#define ALTERA_UART_STATUS_EOP_MSK	0x1000	/* EOP written/read */

						/* Enable interrupt on... */
#define ALTERA_UART_CONTROL_PE_MSK	0x0001	/* ...parity error */
#define ALTERA_UART_CONTROL_FE_MSK	0x0002	/* ...framing error */
#define ALTERA_UART_CONTROL_BRK_MSK	0x0004	/* ...break */
#define ALTERA_UART_CONTROL_ROE_MSK	0x0008	/* ...RX overrun */
#define ALTERA_UART_CONTROL_TOE_MSK	0x0010	/* ...TX overrun */
#define ALTERA_UART_CONTROL_TMT_MSK	0x0020	/* ...TX shift register empty */
#define ALTERA_UART_CONTROL_TRDY_MSK	0x0040	/* ...TX ready */
#define ALTERA_UART_CONTROL_RRDY_MSK	0x0080	/* ...RX ready */
#define ALTERA_UART_CONTROL_E_MSK	0x0100	/* ...exception*/

#define ALTERA_UART_CONTROL_TRBK_MSK	0x0200	/* TX break */
#define ALTERA_UART_CONTROL_DCTS_MSK	0x0400	/* Interrupt on CTS change */
#define ALTERA_UART_CONTROL_RTS_MSK	0x0800	/* RTS signal */
#define ALTERA_UART_CONTROL_EOP_MSK	0x1000	/* Interrupt on EOP */

/*
 * Local per-uart structure.
 */
struct altera_uart {
	struct uart_port port;
	unsigned int sigs;	/* Local copy of line sigs */
	unsigned short imr;	/* Local IMR mirror */
};

static unsigned int altera_uart_tx_empty(struct uart_port *port)
{
	return (readl(port->membase + ALTERA_UART_STATUS_REG) &
		ALTERA_UART_STATUS_TMT_MSK) ? TIOCSER_TEMT : 0;
}

static unsigned int altera_uart_get_mctrl(struct uart_port *port)
{
	struct altera_uart *pp = container_of(port, struct altera_uart, port);
	unsigned int sigs;

	sigs =
	    (readl(port->membase + ALTERA_UART_STATUS_REG) &
	     ALTERA_UART_STATUS_CTS_MSK) ? TIOCM_CTS : 0;
	sigs |= (pp->sigs & TIOCM_RTS);

	return sigs;
}

static void altera_uart_set_mctrl(struct uart_port *port, unsigned int sigs)
{
	struct altera_uart *pp = container_of(port, struct altera_uart, port);

	pp->sigs = sigs;
	if (sigs & TIOCM_RTS)
		pp->imr |= ALTERA_UART_CONTROL_RTS_MSK;
	else
		pp->imr &= ~ALTERA_UART_CONTROL_RTS_MSK;
	writel(pp->imr, port->membase + ALTERA_UART_CONTROL_REG);
}

static void altera_uart_start_tx(struct uart_port *port)
{
	struct altera_uart *pp = container_of(port, struct altera_uart, port);

	pp->imr |= ALTERA_UART_CONTROL_TRDY_MSK;
	writel(pp->imr, port->membase + ALTERA_UART_CONTROL_REG);
}

static void altera_uart_stop_tx(struct uart_port *port)
{
	struct altera_uart *pp = container_of(port, struct altera_uart, port);

	pp->imr &= ~ALTERA_UART_CONTROL_TRDY_MSK;
	writel(pp->imr, port->membase + ALTERA_UART_CONTROL_REG);
}

static void altera_uart_stop_rx(struct uart_port *port)
{
	struct altera_uart *pp = container_of(port, struct altera_uart, port);

	pp->imr &= ~ALTERA_UART_CONTROL_RRDY_MSK;
	writel(pp->imr, port->membase + ALTERA_UART_CONTROL_REG);
}

static void altera_uart_break_ctl(struct uart_port *port, int break_state)
{
	struct altera_uart *pp = container_of(port, struct altera_uart, port);
	unsigned long flags;

	spin_lock_irqsave(&port->lock, flags);
	if (break_state == -1)
		pp->imr |= ALTERA_UART_CONTROL_TRBK_MSK;
	else
		pp->imr &= ~ALTERA_UART_CONTROL_TRBK_MSK;
	writel(pp->imr, port->membase + ALTERA_UART_CONTROL_REG);
	spin_unlock_irqrestore(&port->lock, flags);
}

static void altera_uart_enable_ms(struct uart_port *port)
{
}

static void altera_uart_set_termios(struct uart_port *port,
				    struct ktermios *termios,
				    struct ktermios *old)
{
	unsigned long flags;
	unsigned int baud, baudclk;

	baud = uart_get_baud_rate(port, termios, old, 0, 4000000);
	baudclk = port->uartclk / baud;

	if (old)
		tty_termios_copy_hw(termios, old);
	tty_termios_encode_baud_rate(termios, baud, baud);

	spin_lock_irqsave(&port->lock, flags);
	writel(baudclk, port->membase + ALTERA_UART_DIVISOR_REG);
	spin_unlock_irqrestore(&port->lock, flags);
}

static void altera_uart_rx_chars(struct altera_uart *pp)
{
	struct uart_port *port = &pp->port;
	unsigned char ch, flag;
	unsigned short status;

	while ((status = readl(port->membase + ALTERA_UART_STATUS_REG)) &
	       ALTERA_UART_STATUS_RRDY_MSK) {
		ch = readl(port->membase + ALTERA_UART_RXDATA_REG);
		flag = TTY_NORMAL;
		port->icount.rx++;

		if (status & ALTERA_UART_STATUS_E_MSK) {
			writel(status, port->membase + ALTERA_UART_STATUS_REG);

			if (status & ALTERA_UART_STATUS_BRK_MSK) {
				port->icount.brk++;
				if (uart_handle_break(port))
					continue;
			} else if (status & ALTERA_UART_STATUS_PE_MSK) {
				port->icount.parity++;
			} else if (status & ALTERA_UART_STATUS_ROE_MSK) {
				port->icount.overrun++;
			} else if (status & ALTERA_UART_STATUS_FE_MSK) {
				port->icount.frame++;
			}

			status &= port->read_status_mask;

			if (status & ALTERA_UART_STATUS_BRK_MSK)
				flag = TTY_BREAK;
			else if (status & ALTERA_UART_STATUS_PE_MSK)
				flag = TTY_PARITY;
			else if (status & ALTERA_UART_STATUS_FE_MSK)
				flag = TTY_FRAME;
		}

		if (uart_handle_sysrq_char(port, ch))
			continue;
		uart_insert_char(port, status, ALTERA_UART_STATUS_ROE_MSK, ch,
				 flag);
	}

	tty_flip_buffer_push(port->state->port.tty);
}

static void altera_uart_tx_chars(struct altera_uart *pp)
{
	struct uart_port *port = &pp->port;
	struct circ_buf *xmit = &port->state->xmit;

	if (port->x_char) {
		/* Send special char - probably flow control */
		writel(port->x_char, port->membase + ALTERA_UART_TXDATA_REG);
		port->x_char = 0;
		port->icount.tx++;
		return;
	}

	while (readl(port->membase + ALTERA_UART_STATUS_REG) &
	       ALTERA_UART_STATUS_TRDY_MSK) {
		if (xmit->head == xmit->tail)
			break;
		writel(xmit->buf[xmit->tail],
		       port->membase + ALTERA_UART_TXDATA_REG);
		xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
		port->icount.tx++;
	}

	if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
		uart_write_wakeup(port);

	if (xmit->head == xmit->tail) {
		pp->imr &= ~ALTERA_UART_CONTROL_TRDY_MSK;
		writel(pp->imr, port->membase + ALTERA_UART_CONTROL_REG);
	}
}

static irqreturn_t altera_uart_interrupt(int irq, void *data)
{
	struct uart_port *port = data;
	struct altera_uart *pp = container_of(port, struct altera_uart, port);
	unsigned int isr;

	isr = readl(port->membase + ALTERA_UART_STATUS_REG) & pp->imr;

	spin_lock(&port->lock);
	if (isr & ALTERA_UART_STATUS_RRDY_MSK)
		altera_uart_rx_chars(pp);
	if (isr & ALTERA_UART_STATUS_TRDY_MSK)
		altera_uart_tx_chars(pp);
	spin_unlock(&port->lock);

	return IRQ_RETVAL(isr);
}

static void altera_uart_config_port(struct uart_port *port, int flags)
{
	port->type = PORT_ALTERA_UART;

	/* Clear mask, so no surprise interrupts. */
	writel(0, port->membase + ALTERA_UART_CONTROL_REG);
	/* Clear status register */
	writel(0, port->membase + ALTERA_UART_STATUS_REG);
}

static int altera_uart_startup(struct uart_port *port)
{
	struct altera_uart *pp = container_of(port, struct altera_uart, port);
	unsigned long flags;
	int ret;

	ret = request_irq(port->irq, altera_uart_interrupt, IRQF_DISABLED,
			DRV_NAME, port);
	if (ret) {
		pr_err(DRV_NAME ": unable to attach Altera UART %d "
		       "interrupt vector=%d\n", port->line, port->irq);
		return ret;
	}

	spin_lock_irqsave(&port->lock, flags);

	/* Enable RX interrupts now */
	pp->imr = ALTERA_UART_CONTROL_RRDY_MSK;
	writel(pp->imr, port->membase + ALTERA_UART_CONTROL_REG);

	spin_unlock_irqrestore(&port->lock, flags);

	return 0;
}

static void altera_uart_shutdown(struct uart_port *port)
{
	struct altera_uart *pp = container_of(port, struct altera_uart, port);
	unsigned long flags;

	spin_lock_irqsave(&port->lock, flags);

	/* Disable all interrupts now */
	pp->imr = 0;
	writel(pp->imr, port->membase + ALTERA_UART_CONTROL_REG);

	spin_unlock_irqrestore(&port->lock, flags);

	free_irq(port->irq, port);
}

static const char *altera_uart_type(struct uart_port *port)
{
	return (port->type == PORT_ALTERA_UART) ? "Altera UART" : NULL;
}

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

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

static int altera_uart_verify_port(struct uart_port *port,
				   struct serial_struct *ser)
{
	if ((ser->type != PORT_UNKNOWN) && (ser->type != PORT_ALTERA_UART))
		return -EINVAL;
	return 0;
}

/*
 *	Define the basic serial functions we support.
 */
static struct uart_ops altera_uart_ops = {
	.tx_empty	= altera_uart_tx_empty,
	.get_mctrl	= altera_uart_get_mctrl,
	.set_mctrl	= altera_uart_set_mctrl,
	.start_tx	= altera_uart_start_tx,
	.stop_tx	= altera_uart_stop_tx,
	.stop_rx	= altera_uart_stop_rx,
	.enable_ms	= altera_uart_enable_ms,
	.break_ctl	= altera_uart_break_ctl,
	.startup	= altera_uart_startup,
	.shutdown	= altera_uart_shutdown,
	.set_termios	= altera_uart_set_termios,
	.type		= altera_uart_type,
	.request_port	= altera_uart_request_port,
	.release_port	= altera_uart_release_port,
	.config_port	= altera_uart_config_port,
	.verify_port	= altera_uart_verify_port,
};

static struct altera_uart altera_uart_ports[CONFIG_SERIAL_ALTERA_UART_MAXPORTS];

#if defined(CONFIG_SERIAL_ALTERA_UART_CONSOLE)

int __init early_altera_uart_setup(struct altera_uart_platform_uart *platp)
{
	struct uart_port *port;
	int i;

	for (i = 0; i < CONFIG_SERIAL_ALTERA_UART_MAXPORTS && platp[i].mapbase; i++) {
		port = &altera_uart_ports[i].port;

		port->line = i;
		port->type = PORT_ALTERA_UART;
		port->mapbase = platp[i].mapbase;
		port->membase = ioremap(port->mapbase, ALTERA_UART_SIZE);
		port->iotype = SERIAL_IO_MEM;
		port->irq = platp[i].irq;
		port->uartclk = platp[i].uartclk;
		port->flags = ASYNC_BOOT_AUTOCONF;
		port->ops = &altera_uart_ops;
	}

	return 0;
}

static void altera_uart_console_putc(struct console *co, const char c)
{
	struct uart_port *port = &(altera_uart_ports + co->index)->port;
	int i;

	for (i = 0; i < 0x10000; i++) {
		if (readl(port->membase + ALTERA_UART_STATUS_REG) &
		    ALTERA_UART_STATUS_TRDY_MSK)
			break;
	}
	writel(c, port->membase + ALTERA_UART_TXDATA_REG);
	for (i = 0; i < 0x10000; i++) {
		if (readl(port->membase + ALTERA_UART_STATUS_REG) &
		    ALTERA_UART_STATUS_TRDY_MSK)
			break;
	}
}

static void altera_uart_console_write(struct console *co, const char *s,
				      unsigned int count)
{
	for (; count; count--, s++) {
		altera_uart_console_putc(co, *s);
		if (*s == '\n')
			altera_uart_console_putc(co, '\r');
	}
}

static int __init altera_uart_console_setup(struct console *co, char *options)
{
	struct uart_port *port;
	int baud = CONFIG_SERIAL_ALTERA_UART_BAUDRATE;
	int bits = 8;
	int parity = 'n';
	int flow = 'n';

	if (co->index < 0 || co->index >= CONFIG_SERIAL_ALTERA_UART_MAXPORTS)
		return -EINVAL;
	port = &altera_uart_ports[co->index].port;
	if (port->membase == 0)
		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 altera_uart_driver;

static struct console altera_uart_console = {
	.name	= "ttyS",
	.write	= altera_uart_console_write,
	.device	= uart_console_device,
	.setup	= altera_uart_console_setup,
	.flags	= CON_PRINTBUFFER,
	.index	= -1,
	.data	= &altera_uart_driver,
};

static int __init altera_uart_console_init(void)
{
	register_console(&altera_uart_console);
	return 0;
}

console_initcall(altera_uart_console_init);

#define	ALTERA_UART_CONSOLE	(&altera_uart_console)

#else

#define	ALTERA_UART_CONSOLE	NULL

#endif /* CONFIG_ALTERA_UART_CONSOLE */

/*
 *	Define the altera_uart UART driver structure.
 */
static struct uart_driver altera_uart_driver = {
	.owner		= THIS_MODULE,
	.driver_name	= DRV_NAME,
	.dev_name	= "ttyS",
	.major		= TTY_MAJOR,
	.minor		= 64,
	.nr		= CONFIG_SERIAL_ALTERA_UART_MAXPORTS,
	.cons		= ALTERA_UART_CONSOLE,
};

static int __devinit altera_uart_probe(struct platform_device *pdev)
{
	struct altera_uart_platform_uart *platp = pdev->dev.platform_data;
	struct uart_port *port;
	int i;

	for (i = 0; i < CONFIG_SERIAL_ALTERA_UART_MAXPORTS && platp[i].mapbase; i++) {
		port = &altera_uart_ports[i].port;

		port->line = i;
		port->type = PORT_ALTERA_UART;
		port->mapbase = platp[i].mapbase;
		port->membase = ioremap(port->mapbase, ALTERA_UART_SIZE);
		port->iotype = SERIAL_IO_MEM;
		port->irq = platp[i].irq;
		port->uartclk = platp[i].uartclk;
		port->ops = &altera_uart_ops;
		port->flags = ASYNC_BOOT_AUTOCONF;

		uart_add_one_port(&altera_uart_driver, port);
	}

	return 0;
}

static int altera_uart_remove(struct platform_device *pdev)
{
	struct uart_port *port;
	int i;

	for (i = 0; i < CONFIG_SERIAL_ALTERA_UART_MAXPORTS; i++) {
		port = &altera_uart_ports[i].port;
		if (port)
			uart_remove_one_port(&altera_uart_driver, port);
	}

	return 0;
}

static struct platform_driver altera_uart_platform_driver = {
	.probe	= altera_uart_probe,
	.remove	= __devexit_p(altera_uart_remove),
	.driver	= {
		.name	= DRV_NAME,
		.owner	= THIS_MODULE,
		.pm	= NULL,
	},
};

static int __init altera_uart_init(void)
{
	int rc;

	rc = uart_register_driver(&altera_uart_driver);
	if (rc)
		return rc;
	rc = platform_driver_register(&altera_uart_platform_driver);
	if (rc) {
		uart_unregister_driver(&altera_uart_driver);
		return rc;
	}
	return 0;
}

static void __exit altera_uart_exit(void)
{
	platform_driver_unregister(&altera_uart_platform_driver);
	uart_unregister_driver(&altera_uart_driver);
}

module_init(altera_uart_init);
module_exit(altera_uart_exit);

MODULE_DESCRIPTION("Altera UART driver");
MODULE_AUTHOR("Thomas Chou <thomas@wytron.com.tw>");
MODULE_LICENSE("GPL");
MODULE_ALIAS("platform:" DRV_NAME);
Commit	Line	Data
6b7d8f8b TK	1	/*
	2	* altera_uart.c -- Altera UART driver
	3	*
	4	* Based on mcf.c -- Freescale ColdFire UART driver
	5	*
	6	* (C) Copyright 2003-2007, Greg Ungerer <gerg@snapgear.com>
	7	* (C) Copyright 2008, Thomas Chou <thomas@wytron.com.tw>
	8	* (C) Copyright 2010, Tobias Klauser <tklauser@distanz.ch>
	9	*
	10	* This program is free software; you can redistribute it and/or modify
	11	* it under the terms of the GNU General Public License as published by
	12	* the Free Software Foundation; either version 2 of the License, or
	13	* (at your option) any later version.
	14	*/
	15
	16	#include <linux/kernel.h>
	17	#include <linux/init.h>
	18	#include <linux/interrupt.h>
	19	#include <linux/module.h>
	20	#include <linux/console.h>
	21	#include <linux/tty.h>
	22	#include <linux/tty_flip.h>
	23	#include <linux/serial.h>
	24	#include <linux/serial_core.h>
	25	#include <linux/platform_device.h>
	26	#include <linux/io.h>
	27	#include <linux/altera_uart.h>
	28
	29	#define DRV_NAME "altera_uart"
	30
	31	/*
	32	* Altera UART register definitions according to the Nios UART datasheet:
	33	* http://www.altera.com/literature/ds/ds_nios_uart.pdf
	34	*/
	35
	36	#define ALTERA_UART_SIZE 32
	37
	38	#define ALTERA_UART_RXDATA_REG 0
	39	#define ALTERA_UART_TXDATA_REG 4
	40	#define ALTERA_UART_STATUS_REG 8
	41	#define ALTERA_UART_CONTROL_REG 12
	42	#define ALTERA_UART_DIVISOR_REG 16
	43	#define ALTERA_UART_EOP_REG 20
	44
	45	#define ALTERA_UART_STATUS_PE_MSK 0x0001 /* parity error */
	46	#define ALTERA_UART_STATUS_FE_MSK 0x0002 /* framing error */
	47	#define ALTERA_UART_STATUS_BRK_MSK 0x0004 /* break */
	48	#define ALTERA_UART_STATUS_ROE_MSK 0x0008 /* RX overrun error */
	49	#define ALTERA_UART_STATUS_TOE_MSK 0x0010 /* TX overrun error */
	50	#define ALTERA_UART_STATUS_TMT_MSK 0x0020 /* TX shift register state */
	51	#define ALTERA_UART_STATUS_TRDY_MSK 0x0040 /* TX ready */
	52	#define ALTERA_UART_STATUS_RRDY_MSK 0x0080 /* RX ready */
	53	#define ALTERA_UART_STATUS_E_MSK 0x0100 /* exception condition */
	54	#define ALTERA_UART_STATUS_DCTS_MSK 0x0400 /* CTS logic-level change */
	55	#define ALTERA_UART_STATUS_CTS_MSK 0x0800 /* CTS logic state */
	56	#define ALTERA_UART_STATUS_EOP_MSK 0x1000 /* EOP written/read */
	57
	58	/* Enable interrupt on... */
	59	#define ALTERA_UART_CONTROL_PE_MSK 0x0001 /* ...parity error */
	60	#define ALTERA_UART_CONTROL_FE_MSK 0x0002 /* ...framing error */
	61	#define ALTERA_UART_CONTROL_BRK_MSK 0x0004 /* ...break */
	62	#define ALTERA_UART_CONTROL_ROE_MSK 0x0008 /* ...RX overrun */
	63	#define ALTERA_UART_CONTROL_TOE_MSK 0x0010 /* ...TX overrun */
	64	#define ALTERA_UART_CONTROL_TMT_MSK 0x0020 /* ...TX shift register empty */
65	#define ALTERA_UART_CONTROL_TRDY_MSK 0x0040 /* ...TX ready */
66	#define ALTERA_UART_CONTROL_RRDY_MSK 0x0080 /* ...RX ready */
67	#define ALTERA_UART_CONTROL_E_MSK 0x0100 /* ...exception*/
68
69	#define ALTERA_UART_CONTROL_TRBK_MSK 0x0200 /* TX break */
70	#define ALTERA_UART_CONTROL_DCTS_MSK 0x0400 /* Interrupt on CTS change */
71	#define ALTERA_UART_CONTROL_RTS_MSK 0x0800 /* RTS signal */
72	#define ALTERA_UART_CONTROL_EOP_MSK 0x1000 /* Interrupt on EOP */
73
74	/*
75	* Local per-uart structure.
76	*/
77	struct altera_uart {
78	struct uart_port port;
79	unsigned int sigs; /* Local copy of line sigs */
80	unsigned short imr; /* Local IMR mirror */
81	};
82
83	static unsigned int altera_uart_tx_empty(struct uart_port *port)
84	{
85	return (readl(port->membase + ALTERA_UART_STATUS_REG) &
86	ALTERA_UART_STATUS_TMT_MSK) ? TIOCSER_TEMT : 0;
87	}
88
89	static unsigned int altera_uart_get_mctrl(struct uart_port *port)
90	{
91	struct altera_uart *pp = container_of(port, struct altera_uart, port);
6b7d8f8b TK	92	unsigned int sigs;
6b7d8f8b TK	93
6b7d8f8b TK	94	sigs =
	95	(readl(port->membase + ALTERA_UART_STATUS_REG) &
	96	ALTERA_UART_STATUS_CTS_MSK) ? TIOCM_CTS : 0;
	97	sigs \|= (pp->sigs & TIOCM_RTS);
6b7d8f8b TK	98
	99	return sigs;
	100	}
	101
	102	static void altera_uart_set_mctrl(struct uart_port *port, unsigned int sigs)
	103	{
	104	struct altera_uart *pp = container_of(port, struct altera_uart, port);
6b7d8f8b	105
6b7d8f8b TK	106	pp->sigs = sigs;
	107	if (sigs & TIOCM_RTS)
	108	pp->imr \|= ALTERA_UART_CONTROL_RTS_MSK;
	109	else
	110	pp->imr &= ~ALTERA_UART_CONTROL_RTS_MSK;
	111	writel(pp->imr, port->membase + ALTERA_UART_CONTROL_REG);
6b7d8f8b TK	112	}
	113
	114	static void altera_uart_start_tx(struct uart_port *port)
	115	{
	116	struct altera_uart *pp = container_of(port, struct altera_uart, port);
6b7d8f8b	117
6b7d8f8b TK	118	pp->imr \|= ALTERA_UART_CONTROL_TRDY_MSK;
6b7d8f8b TK	119	writel(pp->imr, port->membase + ALTERA_UART_CONTROL_REG);
6b7d8f8b TK	120	}
	121
	122	static void altera_uart_stop_tx(struct uart_port *port)
	123	{
	124	struct altera_uart *pp = container_of(port, struct altera_uart, port);
6b7d8f8b	125
6b7d8f8b TK	126	pp->imr &= ~ALTERA_UART_CONTROL_TRDY_MSK;
6b7d8f8b TK	127	writel(pp->imr, port->membase + ALTERA_UART_CONTROL_REG);
6b7d8f8b TK	128	}
	129
	130	static void altera_uart_stop_rx(struct uart_port *port)
	131	{
	132	struct altera_uart *pp = container_of(port, struct altera_uart, port);
6b7d8f8b	133
6b7d8f8b TK	134	pp->imr &= ~ALTERA_UART_CONTROL_RRDY_MSK;
6b7d8f8b TK	135	writel(pp->imr, port->membase + ALTERA_UART_CONTROL_REG);
6b7d8f8b TK	136	}
	137
	138	static void altera_uart_break_ctl(struct uart_port *port, int break_state)
	139	{
	140	struct altera_uart *pp = container_of(port, struct altera_uart, port);
	141	unsigned long flags;
	142
	143	spin_lock_irqsave(&port->lock, flags);
	144	if (break_state == -1)
	145	pp->imr \|= ALTERA_UART_CONTROL_TRBK_MSK;
	146	else
	147	pp->imr &= ~ALTERA_UART_CONTROL_TRBK_MSK;
	148	writel(pp->imr, port->membase + ALTERA_UART_CONTROL_REG);
	149	spin_unlock_irqrestore(&port->lock, flags);
	150	}
	151
	152	static void altera_uart_enable_ms(struct uart_port *port)
	153	{
	154	}
	155
	156	static void altera_uart_set_termios(struct uart_port *port,
	157	struct ktermios *termios,
	158	struct ktermios *old)
	159	{
	160	unsigned long flags;
	161	unsigned int baud, baudclk;
	162
	163	baud = uart_get_baud_rate(port, termios, old, 0, 4000000);
	164	baudclk = port->uartclk / baud;
	165
	166	if (old)
	167	tty_termios_copy_hw(termios, old);
	168	tty_termios_encode_baud_rate(termios, baud, baud);
	169
	170	spin_lock_irqsave(&port->lock, flags);
	171	writel(baudclk, port->membase + ALTERA_UART_DIVISOR_REG);
	172	spin_unlock_irqrestore(&port->lock, flags);
	173	}
	174
	175	static void altera_uart_rx_chars(struct altera_uart *pp)
	176	{
	177	struct uart_port *port = &pp->port;
	178	unsigned char ch, flag;
	179	unsigned short status;
	180
	181	while ((status = readl(port->membase + ALTERA_UART_STATUS_REG)) &
	182	ALTERA_UART_STATUS_RRDY_MSK) {
	183	ch = readl(port->membase + ALTERA_UART_RXDATA_REG);
	184	flag = TTY_NORMAL;
	185	port->icount.rx++;
	186
	187	if (status & ALTERA_UART_STATUS_E_MSK) {
	188	writel(status, port->membase + ALTERA_UART_STATUS_REG);
	189
	190	if (status & ALTERA_UART_STATUS_BRK_MSK) {
	191	port->icount.brk++;
	192	if (uart_handle_break(port))
	193	continue;
	194	} else if (status & ALTERA_UART_STATUS_PE_MSK) {
	195	port->icount.parity++;
	196	} else if (status & ALTERA_UART_STATUS_ROE_MSK) {
	197	port->icount.overrun++;
	198	} else if (status & ALTERA_UART_STATUS_FE_MSK) {
	199	port->icount.frame++;
200	}
201
202	status &= port->read_status_mask;
203
204	if (status & ALTERA_UART_STATUS_BRK_MSK)
205	flag = TTY_BREAK;
206	else if (status & ALTERA_UART_STATUS_PE_MSK)
207	flag = TTY_PARITY;
208	else if (status & ALTERA_UART_STATUS_FE_MSK)
209	flag = TTY_FRAME;
210	}
211
212	if (uart_handle_sysrq_char(port, ch))
213	continue;
214	uart_insert_char(port, status, ALTERA_UART_STATUS_ROE_MSK, ch,
215	flag);
216	}
217
218	tty_flip_buffer_push(port->state->port.tty);
219	}
220
221	static void altera_uart_tx_chars(struct altera_uart *pp)
222	{
223	struct uart_port *port = &pp->port;
224	struct circ_buf *xmit = &port->state->xmit;
225
226	if (port->x_char) {
227	/* Send special char - probably flow control */
228	writel(port->x_char, port->membase + ALTERA_UART_TXDATA_REG);
229	port->x_char = 0;
230	port->icount.tx++;
231	return;
232	}
233
234	while (readl(port->membase + ALTERA_UART_STATUS_REG) &
235	ALTERA_UART_STATUS_TRDY_MSK) {
236	if (xmit->head == xmit->tail)
237	break;
238	writel(xmit->buf[xmit->tail],
239	port->membase + ALTERA_UART_TXDATA_REG);
240	xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
241	port->icount.tx++;
242	}
243
244	if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
245	uart_write_wakeup(port);
246
247	if (xmit->head == xmit->tail) {
248	pp->imr &= ~ALTERA_UART_CONTROL_TRDY_MSK;
249	writel(pp->imr, port->membase + ALTERA_UART_CONTROL_REG);
250	}
251	}
252
253	static irqreturn_t altera_uart_interrupt(int irq, void *data)
254	{
255	struct uart_port *port = data;
256	struct altera_uart *pp = container_of(port, struct altera_uart, port);
257	unsigned int isr;
258
259	isr = readl(port->membase + ALTERA_UART_STATUS_REG) & pp->imr;
d8d721f4 TK	260
d8d721f4 TK	261	spin_lock(&port->lock);
6b7d8f8b TK	262	if (isr & ALTERA_UART_STATUS_RRDY_MSK)
	263	altera_uart_rx_chars(pp);
	264	if (isr & ALTERA_UART_STATUS_TRDY_MSK)
	265	altera_uart_tx_chars(pp);
d8d721f4 TK	266	spin_unlock(&port->lock);
d8d721f4 TK	267
6b7d8f8b TK	268	return IRQ_RETVAL(isr);
	269	}
	270
	271	static void altera_uart_config_port(struct uart_port *port, int flags)
	272	{
	273	port->type = PORT_ALTERA_UART;
	274
	275	/* Clear mask, so no surprise interrupts. */
	276	writel(0, port->membase + ALTERA_UART_CONTROL_REG);
	277	/* Clear status register */
	278	writel(0, port->membase + ALTERA_UART_STATUS_REG);
	279	}
	280
	281	static int altera_uart_startup(struct uart_port *port)
	282	{
	283	struct altera_uart *pp = container_of(port, struct altera_uart, port);
	284	unsigned long flags;
	285	int ret;
	286
	287	ret = request_irq(port->irq, altera_uart_interrupt, IRQF_DISABLED,
	288	DRV_NAME, port);
	289	if (ret) {
	290	pr_err(DRV_NAME ": unable to attach Altera UART %d "
	291	"interrupt vector=%d\n", port->line, port->irq);
	292	return ret;
	293	}
	294
	295	spin_lock_irqsave(&port->lock, flags);
	296
	297	/* Enable RX interrupts now */
	298	pp->imr = ALTERA_UART_CONTROL_RRDY_MSK;
	299	writel(pp->imr, port->membase + ALTERA_UART_CONTROL_REG);
	300
	301	spin_unlock_irqrestore(&port->lock, flags);
	302
	303	return 0;
	304	}
	305
	306	static void altera_uart_shutdown(struct uart_port *port)
	307	{
	308	struct altera_uart *pp = container_of(port, struct altera_uart, port);
	309	unsigned long flags;
	310
	311	spin_lock_irqsave(&port->lock, flags);
	312
	313	/* Disable all interrupts now */
	314	pp->imr = 0;
	315	writel(pp->imr, port->membase + ALTERA_UART_CONTROL_REG);
	316
	317	spin_unlock_irqrestore(&port->lock, flags);
	318
	319	free_irq(port->irq, port);
	320	}
	321
	322	static const char altera_uart_type(struct uart_port port)
	323	{
	324	return (port->type == PORT_ALTERA_UART) ? "Altera UART" : NULL;
	325	}
	326
	327	static int altera_uart_request_port(struct uart_port *port)
	328	{
	329	/* UARTs always present */
	330	return 0;
	331	}
332
333	static void altera_uart_release_port(struct uart_port *port)
334	{
335	/* Nothing to release... */
336	}
337
338	static int altera_uart_verify_port(struct uart_port *port,
339	struct serial_struct *ser)
340	{
341	if ((ser->type != PORT_UNKNOWN) && (ser->type != PORT_ALTERA_UART))
342	return -EINVAL;
343	return 0;
344	}
345
346	/*
347	* Define the basic serial functions we support.
348	*/
349	static struct uart_ops altera_uart_ops = {
350	.tx_empty = altera_uart_tx_empty,
351	.get_mctrl = altera_uart_get_mctrl,
352	.set_mctrl = altera_uart_set_mctrl,
353	.start_tx = altera_uart_start_tx,
354	.stop_tx = altera_uart_stop_tx,
355	.stop_rx = altera_uart_stop_rx,
356	.enable_ms = altera_uart_enable_ms,
357	.break_ctl = altera_uart_break_ctl,
358	.startup = altera_uart_startup,
359	.shutdown = altera_uart_shutdown,
360	.set_termios = altera_uart_set_termios,
361	.type = altera_uart_type,
362	.request_port = altera_uart_request_port,
363	.release_port = altera_uart_release_port,
364	.config_port = altera_uart_config_port,
365	.verify_port = altera_uart_verify_port,
366	};
367
368	static struct altera_uart altera_uart_ports[CONFIG_SERIAL_ALTERA_UART_MAXPORTS];
369
370	#if defined(CONFIG_SERIAL_ALTERA_UART_CONSOLE)
371
372	int __init early_altera_uart_setup(struct altera_uart_platform_uart *platp)
373	{
374	struct uart_port *port;
375	int i;
376
377	for (i = 0; i < CONFIG_SERIAL_ALTERA_UART_MAXPORTS && platp[i].mapbase; i++) {
378	port = &altera_uart_ports[i].port;
379
380	port->line = i;
381	port->type = PORT_ALTERA_UART;
382	port->mapbase = platp[i].mapbase;
383	port->membase = ioremap(port->mapbase, ALTERA_UART_SIZE);
384	port->iotype = SERIAL_IO_MEM;
385	port->irq = platp[i].irq;
386	port->uartclk = platp[i].uartclk;
387	port->flags = ASYNC_BOOT_AUTOCONF;
388	port->ops = &altera_uart_ops;
389	}
390
391	return 0;
392	}
393
394	static void altera_uart_console_putc(struct console *co, const char c)
395	{
396	struct uart_port *port = &(altera_uart_ports + co->index)->port;
397	int i;
398
399	for (i = 0; i < 0x10000; i++) {
400	if (readl(port->membase + ALTERA_UART_STATUS_REG) &
401	ALTERA_UART_STATUS_TRDY_MSK)
402	break;
403	}
404	writel(c, port->membase + ALTERA_UART_TXDATA_REG);
405	for (i = 0; i < 0x10000; i++) {
406	if (readl(port->membase + ALTERA_UART_STATUS_REG) &
407	ALTERA_UART_STATUS_TRDY_MSK)
408	break;
409	}
410	}
411
412	static void altera_uart_console_write(struct console co, const char s,
413	unsigned int count)
414	{
415	for (; count; count--, s++) {
416	altera_uart_console_putc(co, *s);
417	if (*s == '\n')
418	altera_uart_console_putc(co, '\r');
419	}
420	}
421
422	static int __init altera_uart_console_setup(struct console co, char options)
423	{
424	struct uart_port *port;
425	int baud = CONFIG_SERIAL_ALTERA_UART_BAUDRATE;
426	int bits = 8;
427	int parity = 'n';
428	int flow = 'n';
429
430	if (co->index < 0 \|\| co->index >= CONFIG_SERIAL_ALTERA_UART_MAXPORTS)
431	return -EINVAL;
432	port = &altera_uart_ports[co->index].port;
433	if (port->membase == 0)
434	return -ENODEV;
435
436	if (options)
437	uart_parse_options(options, &baud, &parity, &bits, &flow);
438
439	return uart_set_options(port, co, baud, parity, bits, flow);
440	}
441
442	static struct uart_driver altera_uart_driver;
443
444	static struct console altera_uart_console = {
445	.name = "ttyS",
446	.write = altera_uart_console_write,
447	.device = uart_console_device,
448	.setup = altera_uart_console_setup,
449	.flags = CON_PRINTBUFFER,
450	.index = -1,
451	.data = &altera_uart_driver,
452	};
453
454	static int __init altera_uart_console_init(void)
455	{
456	register_console(&altera_uart_console);
457	return 0;
458	}
459
460	console_initcall(altera_uart_console_init);
461
462	#define ALTERA_UART_CONSOLE (&altera_uart_console)
463
464	#else
465
466	#define ALTERA_UART_CONSOLE NULL
467
468	#endif /* CONFIG_ALTERA_UART_CONSOLE */
469
470	/*
471	* Define the altera_uart UART driver structure.
472	*/
473	static struct uart_driver altera_uart_driver = {
474	.owner = THIS_MODULE,
475	.driver_name = DRV_NAME,
476	.dev_name = "ttyS",
477	.major = TTY_MAJOR,
478	.minor = 64,
479	.nr = CONFIG_SERIAL_ALTERA_UART_MAXPORTS,
480	.cons = ALTERA_UART_CONSOLE,
481	};
482
483	static int __devinit altera_uart_probe(struct platform_device *pdev)
484	{
485	struct altera_uart_platform_uart *platp = pdev->dev.platform_data;
486	struct uart_port *port;
487	int i;
488
489	for (i = 0; i < CONFIG_SERIAL_ALTERA_UART_MAXPORTS && platp[i].mapbase; i++) {
490	port = &altera_uart_ports[i].port;
491
492	port->line = i;
493	port->type = PORT_ALTERA_UART;
494	port->mapbase = platp[i].mapbase;
495	port->membase = ioremap(port->mapbase, ALTERA_UART_SIZE);
496	port->iotype = SERIAL_IO_MEM;
497	port->irq = platp[i].irq;
498	port->uartclk = platp[i].uartclk;
499	port->ops = &altera_uart_ops;
500	port->flags = ASYNC_BOOT_AUTOCONF;
501
502	uart_add_one_port(&altera_uart_driver, port);
503	}
504
505	return 0;
506	}
507
508	static int altera_uart_remove(struct platform_device *pdev)
509	{
510	struct uart_port *port;
511	int i;
512
513	for (i = 0; i < CONFIG_SERIAL_ALTERA_UART_MAXPORTS; i++) {
514	port = &altera_uart_ports[i].port;
515	if (port)
516	uart_remove_one_port(&altera_uart_driver, port);
517	}
518
519	return 0;
520	}
521
522	static struct platform_driver altera_uart_platform_driver = {
523	.probe = altera_uart_probe,
524	.remove = __devexit_p(altera_uart_remove),
525	.driver = {
526	.name = DRV_NAME,
527	.owner = THIS_MODULE,
528	.pm = NULL,
529	},
530	};
531
532	static int __init altera_uart_init(void)
533	{
534	int rc;
535
536	rc = uart_register_driver(&altera_uart_driver);
537	if (rc)
538	return rc;
539	rc = platform_driver_register(&altera_uart_platform_driver);
540	if (rc) {
541	uart_unregister_driver(&altera_uart_driver);
542	return rc;
543	}
544	return 0;
545	}
546
547	static void __exit altera_uart_exit(void)
548	{
549	platform_driver_unregister(&altera_uart_platform_driver);
550	uart_unregister_driver(&altera_uart_driver);
551	}
552
553	module_init(altera_uart_init);
554	module_exit(altera_uart_exit);
555
556	MODULE_DESCRIPTION("Altera UART driver");
557	MODULE_AUTHOR("Thomas Chou <thomas@wytron.com.tw>");
558	MODULE_LICENSE("GPL");
559	MODULE_ALIAS("platform:" DRV_NAME);