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

/*
 * altera_jtaguart.c -- Altera JTAG 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/of.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_jtaguart.h>

#define DRV_NAME "altera_jtaguart"

/*
 * Altera JTAG UART register definitions according to the Altera JTAG UART
 * datasheet: http://www.altera.com/literature/hb/nios2/n2cpu_nii51009.pdf
 */

#define ALTERA_JTAGUART_SIZE			8

#define ALTERA_JTAGUART_DATA_REG		0

#define ALTERA_JTAGUART_DATA_DATA_MSK		0x000000FF
#define ALTERA_JTAGUART_DATA_RVALID_MSK		0x00008000
#define ALTERA_JTAGUART_DATA_RAVAIL_MSK		0xFFFF0000
#define ALTERA_JTAGUART_DATA_RAVAIL_OFF		16

#define ALTERA_JTAGUART_CONTROL_REG		4

#define ALTERA_JTAGUART_CONTROL_RE_MSK		0x00000001
#define ALTERA_JTAGUART_CONTROL_WE_MSK		0x00000002
#define ALTERA_JTAGUART_CONTROL_RI_MSK		0x00000100
#define ALTERA_JTAGUART_CONTROL_RI_OFF		8
#define ALTERA_JTAGUART_CONTROL_WI_MSK		0x00000200
#define ALTERA_JTAGUART_CONTROL_AC_MSK		0x00000400
#define ALTERA_JTAGUART_CONTROL_WSPACE_MSK	0xFFFF0000
#define ALTERA_JTAGUART_CONTROL_WSPACE_OFF	16

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

static unsigned int altera_jtaguart_tx_empty(struct uart_port *port)
{
	return (readl(port->membase + ALTERA_JTAGUART_CONTROL_REG) &
		ALTERA_JTAGUART_CONTROL_WSPACE_MSK) ? TIOCSER_TEMT : 0;
}

static unsigned int altera_jtaguart_get_mctrl(struct uart_port *port)
{
	return TIOCM_CAR | TIOCM_DSR | TIOCM_CTS;
}

static void altera_jtaguart_set_mctrl(struct uart_port *port, unsigned int sigs)
{
}

static void altera_jtaguart_start_tx(struct uart_port *port)
{
	struct altera_jtaguart *pp =
	    container_of(port, struct altera_jtaguart, port);

	pp->imr |= ALTERA_JTAGUART_CONTROL_WE_MSK;
	writel(pp->imr, port->membase + ALTERA_JTAGUART_CONTROL_REG);
}

static void altera_jtaguart_stop_tx(struct uart_port *port)
{
	struct altera_jtaguart *pp =
	    container_of(port, struct altera_jtaguart, port);

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

static void altera_jtaguart_stop_rx(struct uart_port *port)
{
	struct altera_jtaguart *pp =
	    container_of(port, struct altera_jtaguart, port);

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

static void altera_jtaguart_break_ctl(struct uart_port *port, int break_state)
{
}

static void altera_jtaguart_enable_ms(struct uart_port *port)
{
}

static void altera_jtaguart_set_termios(struct uart_port *port,
					struct ktermios *termios,
					struct ktermios *old)
{
	/* Just copy the old termios settings back */
	if (old)
		tty_termios_copy_hw(termios, old);
}

static void altera_jtaguart_rx_chars(struct altera_jtaguart *pp)
{
	struct uart_port *port = &pp->port;
	unsigned char ch, flag;
	unsigned long status;

	while ((status = readl(port->membase + ALTERA_JTAGUART_DATA_REG)) &
	       ALTERA_JTAGUART_DATA_RVALID_MSK) {
		ch = status & ALTERA_JTAGUART_DATA_DATA_MSK;
		flag = TTY_NORMAL;
		port->icount.rx++;

		if (uart_handle_sysrq_char(port, ch))
			continue;
		uart_insert_char(port, 0, 0, ch, flag);
	}

	tty_flip_buffer_push(&port->state->port);
}

static void altera_jtaguart_tx_chars(struct altera_jtaguart *pp)
{
	struct uart_port *port = &pp->port;
	struct circ_buf *xmit = &port->state->xmit;
	unsigned int pending, count;

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

	pending = uart_circ_chars_pending(xmit);
	if (pending > 0) {
		count = (readl(port->membase + ALTERA_JTAGUART_CONTROL_REG) &
				ALTERA_JTAGUART_CONTROL_WSPACE_MSK) >>
			ALTERA_JTAGUART_CONTROL_WSPACE_OFF;
		if (count > pending)
			count = pending;
		if (count > 0) {
			pending -= count;
			while (count--) {
				writel(xmit->buf[xmit->tail],
				       port->membase + ALTERA_JTAGUART_DATA_REG);
				xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
				port->icount.tx++;
			}
			if (pending < WAKEUP_CHARS)
				uart_write_wakeup(port);
		}
	}

	if (pending == 0) {
		pp->imr &= ~ALTERA_JTAGUART_CONTROL_WE_MSK;
		writel(pp->imr, port->membase + ALTERA_JTAGUART_CONTROL_REG);
	}
}

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

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

	spin_lock(&port->lock);

	if (isr & ALTERA_JTAGUART_CONTROL_RE_MSK)
		altera_jtaguart_rx_chars(pp);
	if (isr & ALTERA_JTAGUART_CONTROL_WE_MSK)
		altera_jtaguart_tx_chars(pp);

	spin_unlock(&port->lock);

	return IRQ_RETVAL(isr);
}

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

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

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

	ret = request_irq(port->irq, altera_jtaguart_interrupt, 0,
			DRV_NAME, port);
	if (ret) {
		pr_err(DRV_NAME ": unable to attach Altera JTAG 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_JTAGUART_CONTROL_RE_MSK;
	writel(pp->imr, port->membase + ALTERA_JTAGUART_CONTROL_REG);

	spin_unlock_irqrestore(&port->lock, flags);

	return 0;
}

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

	spin_lock_irqsave(&port->lock, flags);

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

	spin_unlock_irqrestore(&port->lock, flags);

	free_irq(port->irq, port);
}

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

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

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

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

/*
 *	Define the basic serial functions we support.
 */
static struct uart_ops altera_jtaguart_ops = {
	.tx_empty	= altera_jtaguart_tx_empty,
	.get_mctrl	= altera_jtaguart_get_mctrl,
	.set_mctrl	= altera_jtaguart_set_mctrl,
	.start_tx	= altera_jtaguart_start_tx,
	.stop_tx	= altera_jtaguart_stop_tx,
	.stop_rx	= altera_jtaguart_stop_rx,
	.enable_ms	= altera_jtaguart_enable_ms,
	.break_ctl	= altera_jtaguart_break_ctl,
	.startup	= altera_jtaguart_startup,
	.shutdown	= altera_jtaguart_shutdown,
	.set_termios	= altera_jtaguart_set_termios,
	.type		= altera_jtaguart_type,
	.request_port	= altera_jtaguart_request_port,
	.release_port	= altera_jtaguart_release_port,
	.config_port	= altera_jtaguart_config_port,
	.verify_port	= altera_jtaguart_verify_port,
};

#define ALTERA_JTAGUART_MAXPORTS 1
static struct altera_jtaguart altera_jtaguart_ports[ALTERA_JTAGUART_MAXPORTS];

#if defined(CONFIG_SERIAL_ALTERA_JTAGUART_CONSOLE)

#if defined(CONFIG_SERIAL_ALTERA_JTAGUART_CONSOLE_BYPASS)
static void altera_jtaguart_console_putc(struct console *co, const char c)
{
	struct uart_port *port = &(altera_jtaguart_ports + co->index)->port;
	unsigned long status;
	unsigned long flags;

	spin_lock_irqsave(&port->lock, flags);
	while (((status = readl(port->membase + ALTERA_JTAGUART_CONTROL_REG)) &
		ALTERA_JTAGUART_CONTROL_WSPACE_MSK) == 0) {
		if ((status & ALTERA_JTAGUART_CONTROL_AC_MSK) == 0) {
			spin_unlock_irqrestore(&port->lock, flags);
			return;	/* no connection activity */
		}
		spin_unlock_irqrestore(&port->lock, flags);
		cpu_relax();
		spin_lock_irqsave(&port->lock, flags);
	}
	writel(c, port->membase + ALTERA_JTAGUART_DATA_REG);
	spin_unlock_irqrestore(&port->lock, flags);
}
#else
static void altera_jtaguart_console_putc(struct console *co, const char c)
{
	struct uart_port *port = &(altera_jtaguart_ports + co->index)->port;
	unsigned long flags;

	spin_lock_irqsave(&port->lock, flags);
	while ((readl(port->membase + ALTERA_JTAGUART_CONTROL_REG) &
		ALTERA_JTAGUART_CONTROL_WSPACE_MSK) == 0) {
		spin_unlock_irqrestore(&port->lock, flags);
		cpu_relax();
		spin_lock_irqsave(&port->lock, flags);
	}
	writel(c, port->membase + ALTERA_JTAGUART_DATA_REG);
	spin_unlock_irqrestore(&port->lock, flags);
}
#endif

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

static int __init altera_jtaguart_console_setup(struct console *co,
						char *options)
{
	struct uart_port *port;

	if (co->index < 0 || co->index >= ALTERA_JTAGUART_MAXPORTS)
		return -EINVAL;
	port = &altera_jtaguart_ports[co->index].port;
	if (port->membase == NULL)
		return -ENODEV;
	return 0;
}

static struct uart_driver altera_jtaguart_driver;

static struct console altera_jtaguart_console = {
	.name	= "ttyJ",
	.write	= altera_jtaguart_console_write,
	.device	= uart_console_device,
	.setup	= altera_jtaguart_console_setup,
	.flags	= CON_PRINTBUFFER,
	.index	= -1,
	.data	= &altera_jtaguart_driver,
};

static int __init altera_jtaguart_console_init(void)
{
	register_console(&altera_jtaguart_console);
	return 0;
}

console_initcall(altera_jtaguart_console_init);

#define	ALTERA_JTAGUART_CONSOLE	(&altera_jtaguart_console)

#else

#define	ALTERA_JTAGUART_CONSOLE	NULL

#endif /* CONFIG_ALTERA_JTAGUART_CONSOLE */

static struct uart_driver altera_jtaguart_driver = {
	.owner		= THIS_MODULE,
	.driver_name	= "altera_jtaguart",
	.dev_name	= "ttyJ",
	.major		= ALTERA_JTAGUART_MAJOR,
	.minor		= ALTERA_JTAGUART_MINOR,
	.nr		= ALTERA_JTAGUART_MAXPORTS,
	.cons		= ALTERA_JTAGUART_CONSOLE,
};

static int altera_jtaguart_probe(struct platform_device *pdev)
{
	struct altera_jtaguart_platform_uart *platp = pdev->dev.platform_data;
	struct uart_port *port;
	struct resource *res_irq, *res_mem;
	int i = pdev->id;

	/* -1 emphasizes that the platform must have one port, no .N suffix */
	if (i == -1)
		i = 0;

	if (i >= ALTERA_JTAGUART_MAXPORTS)
		return -EINVAL;

	port = &altera_jtaguart_ports[i].port;

	res_mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
	if (res_mem)
		port->mapbase = res_mem->start;
	else if (platp)
		port->mapbase = platp->mapbase;
	else
		return -ENODEV;

	res_irq = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
	if (res_irq)
		port->irq = res_irq->start;
	else if (platp)
		port->irq = platp->irq;
	else
		return -ENODEV;

	port->membase = ioremap(port->mapbase, ALTERA_JTAGUART_SIZE);
	if (!port->membase)
		return -ENOMEM;

	port->line = i;
	port->type = PORT_ALTERA_JTAGUART;
	port->iotype = SERIAL_IO_MEM;
	port->ops = &altera_jtaguart_ops;
	port->flags = UPF_BOOT_AUTOCONF;

	uart_add_one_port(&altera_jtaguart_driver, port);

	return 0;
}

static int altera_jtaguart_remove(struct platform_device *pdev)
{
	struct uart_port *port;
	int i = pdev->id;

	if (i == -1)
		i = 0;

	port = &altera_jtaguart_ports[i].port;
	uart_remove_one_port(&altera_jtaguart_driver, port);

	return 0;
}

#ifdef CONFIG_OF
static struct of_device_id altera_jtaguart_match[] = {
	{ .compatible = "ALTR,juart-1.0", },
	{},
};
MODULE_DEVICE_TABLE(of, altera_jtaguart_match);
#endif /* CONFIG_OF */

static struct platform_driver altera_jtaguart_platform_driver = {
	.probe	= altera_jtaguart_probe,
	.remove	= altera_jtaguart_remove,
	.driver	= {
		.name		= DRV_NAME,
		.owner		= THIS_MODULE,
		.of_match_table	= of_match_ptr(altera_jtaguart_match),
	},
};

static int __init altera_jtaguart_init(void)
{
	int rc;

	rc = uart_register_driver(&altera_jtaguart_driver);
	if (rc)
		return rc;
	rc = platform_driver_register(&altera_jtaguart_platform_driver);
	if (rc) {
		uart_unregister_driver(&altera_jtaguart_driver);
		return rc;
	}
	return 0;
}

static void __exit altera_jtaguart_exit(void)
{
	platform_driver_unregister(&altera_jtaguart_platform_driver);
	uart_unregister_driver(&altera_jtaguart_driver);
}

module_init(altera_jtaguart_init);
module_exit(altera_jtaguart_exit);

MODULE_DESCRIPTION("Altera JTAG UART driver");
MODULE_AUTHOR("Thomas Chou <thomas@wytron.com.tw>");
MODULE_LICENSE("GPL");
MODULE_ALIAS("platform:" DRV_NAME);
Commit	Line	Data
5bcd6010 TK	1	/*
	2	* altera_jtaguart.c -- Altera JTAG 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>
6b3754d6	21	#include <linux/of.h>
5bcd6010 TK	22	#include <linux/tty.h>
	23	#include <linux/tty_flip.h>
	24	#include <linux/serial.h>
	25	#include <linux/serial_core.h>
	26	#include <linux/platform_device.h>
	27	#include <linux/io.h>
	28	#include <linux/altera_jtaguart.h>
	29
	30	#define DRV_NAME "altera_jtaguart"
	31
	32	/*
	33	* Altera JTAG UART register definitions according to the Altera JTAG UART
	34	* datasheet: http://www.altera.com/literature/hb/nios2/n2cpu_nii51009.pdf
	35	*/
	36
	37	#define ALTERA_JTAGUART_SIZE 8
	38
	39	#define ALTERA_JTAGUART_DATA_REG 0
	40
	41	#define ALTERA_JTAGUART_DATA_DATA_MSK 0x000000FF
	42	#define ALTERA_JTAGUART_DATA_RVALID_MSK 0x00008000
	43	#define ALTERA_JTAGUART_DATA_RAVAIL_MSK 0xFFFF0000
	44	#define ALTERA_JTAGUART_DATA_RAVAIL_OFF 16
	45
	46	#define ALTERA_JTAGUART_CONTROL_REG 4
	47
	48	#define ALTERA_JTAGUART_CONTROL_RE_MSK 0x00000001
	49	#define ALTERA_JTAGUART_CONTROL_WE_MSK 0x00000002
	50	#define ALTERA_JTAGUART_CONTROL_RI_MSK 0x00000100
	51	#define ALTERA_JTAGUART_CONTROL_RI_OFF 8
	52	#define ALTERA_JTAGUART_CONTROL_WI_MSK 0x00000200
	53	#define ALTERA_JTAGUART_CONTROL_AC_MSK 0x00000400
	54	#define ALTERA_JTAGUART_CONTROL_WSPACE_MSK 0xFFFF0000
	55	#define ALTERA_JTAGUART_CONTROL_WSPACE_OFF 16
	56
	57	/*
	58	* Local per-uart structure.
	59	*/
	60	struct altera_jtaguart {
	61	struct uart_port port;
	62	unsigned int sigs; /* Local copy of line sigs */
	63	unsigned long imr; /* Local IMR mirror */
	64	};
	65
	66	static unsigned int altera_jtaguart_tx_empty(struct uart_port *port)
	67	{
	68	return (readl(port->membase + ALTERA_JTAGUART_CONTROL_REG) &
	69	ALTERA_JTAGUART_CONTROL_WSPACE_MSK) ? TIOCSER_TEMT : 0;
	70	}
	71
	72	static unsigned int altera_jtaguart_get_mctrl(struct uart_port *port)
	73	{
	74	return TIOCM_CAR \| TIOCM_DSR \| TIOCM_CTS;
	75	}
	76
	77	static void altera_jtaguart_set_mctrl(struct uart_port *port, unsigned int sigs)
	78	{
	79	}
	80
	81	static void altera_jtaguart_start_tx(struct uart_port *port)
	82	{
	83	struct altera_jtaguart *pp =
	84	container_of(port, struct altera_jtaguart, port);
	85
86	pp->imr \|= ALTERA_JTAGUART_CONTROL_WE_MSK;
87	writel(pp->imr, port->membase + ALTERA_JTAGUART_CONTROL_REG);
88	}
89
90	static void altera_jtaguart_stop_tx(struct uart_port *port)
91	{
92	struct altera_jtaguart *pp =
93	container_of(port, struct altera_jtaguart, port);
94
95	pp->imr &= ~ALTERA_JTAGUART_CONTROL_WE_MSK;
96	writel(pp->imr, port->membase + ALTERA_JTAGUART_CONTROL_REG);
97	}
98
99	static void altera_jtaguart_stop_rx(struct uart_port *port)
100	{
101	struct altera_jtaguart *pp =
102	container_of(port, struct altera_jtaguart, port);
103
104	pp->imr &= ~ALTERA_JTAGUART_CONTROL_RE_MSK;
105	writel(pp->imr, port->membase + ALTERA_JTAGUART_CONTROL_REG);
106	}
107
108	static void altera_jtaguart_break_ctl(struct uart_port *port, int break_state)
109	{
110	}
111
112	static void altera_jtaguart_enable_ms(struct uart_port *port)
113	{
114	}
115
116	static void altera_jtaguart_set_termios(struct uart_port *port,
117	struct ktermios *termios,
118	struct ktermios *old)
119	{
120	/* Just copy the old termios settings back */
121	if (old)
122	tty_termios_copy_hw(termios, old);
123	}
124
125	static void altera_jtaguart_rx_chars(struct altera_jtaguart *pp)
126	{
127	struct uart_port *port = &pp->port;
128	unsigned char ch, flag;
129	unsigned long status;
130
131	while ((status = readl(port->membase + ALTERA_JTAGUART_DATA_REG)) &
132	ALTERA_JTAGUART_DATA_RVALID_MSK) {
133	ch = status & ALTERA_JTAGUART_DATA_DATA_MSK;
134	flag = TTY_NORMAL;
135	port->icount.rx++;
136
137	if (uart_handle_sysrq_char(port, ch))
138	continue;
139	uart_insert_char(port, 0, 0, ch, flag);
140	}
141
2e124b4a	142	tty_flip_buffer_push(&port->state->port);
5bcd6010 TK	143	}
	144
	145	static void altera_jtaguart_tx_chars(struct altera_jtaguart *pp)
	146	{
	147	struct uart_port *port = &pp->port;
	148	struct circ_buf *xmit = &port->state->xmit;
	149	unsigned int pending, count;
	150
	151	if (port->x_char) {
	152	/* Send special char - probably flow control */
	153	writel(port->x_char, port->membase + ALTERA_JTAGUART_DATA_REG);
	154	port->x_char = 0;
	155	port->icount.tx++;
	156	return;
	157	}
	158
	159	pending = uart_circ_chars_pending(xmit);
	160	if (pending > 0) {
	161	count = (readl(port->membase + ALTERA_JTAGUART_CONTROL_REG) &
	162	ALTERA_JTAGUART_CONTROL_WSPACE_MSK) >>
	163	ALTERA_JTAGUART_CONTROL_WSPACE_OFF;
	164	if (count > pending)
	165	count = pending;
	166	if (count > 0) {
	167	pending -= count;
	168	while (count--) {
	169	writel(xmit->buf[xmit->tail],
	170	port->membase + ALTERA_JTAGUART_DATA_REG);
	171	xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
	172	port->icount.tx++;
	173	}
	174	if (pending < WAKEUP_CHARS)
	175	uart_write_wakeup(port);
	176	}
	177	}
	178
	179	if (pending == 0) {
	180	pp->imr &= ~ALTERA_JTAGUART_CONTROL_WE_MSK;
	181	writel(pp->imr, port->membase + ALTERA_JTAGUART_CONTROL_REG);
	182	}
	183	}
	184
	185	static irqreturn_t altera_jtaguart_interrupt(int irq, void *data)
	186	{
	187	struct uart_port *port = data;
	188	struct altera_jtaguart *pp =
	189	container_of(port, struct altera_jtaguart, port);
	190	unsigned int isr;
	191
	192	isr = (readl(port->membase + ALTERA_JTAGUART_CONTROL_REG) >>
	193	ALTERA_JTAGUART_CONTROL_RI_OFF) & pp->imr;
	194
	195	spin_lock(&port->lock);
	196
	197	if (isr & ALTERA_JTAGUART_CONTROL_RE_MSK)
	198	altera_jtaguart_rx_chars(pp);
	199	if (isr & ALTERA_JTAGUART_CONTROL_WE_MSK)
	200	altera_jtaguart_tx_chars(pp);
	201
	202	spin_unlock(&port->lock);
	203
	204	return IRQ_RETVAL(isr);
	205	}
	206
207	static void altera_jtaguart_config_port(struct uart_port *port, int flags)
208	{
209	port->type = PORT_ALTERA_JTAGUART;
210
211	/* Clear mask, so no surprise interrupts. */
212	writel(0, port->membase + ALTERA_JTAGUART_CONTROL_REG);
213	}
214
215	static int altera_jtaguart_startup(struct uart_port *port)
216	{
217	struct altera_jtaguart *pp =
218	container_of(port, struct altera_jtaguart, port);
219	unsigned long flags;
220	int ret;
221
9cfb5c05	222	ret = request_irq(port->irq, altera_jtaguart_interrupt, 0,
5bcd6010 TK	223	DRV_NAME, port);
	224	if (ret) {
	225	pr_err(DRV_NAME ": unable to attach Altera JTAG UART %d "
	226	"interrupt vector=%d\n", port->line, port->irq);
	227	return ret;
	228	}
	229
	230	spin_lock_irqsave(&port->lock, flags);
	231
	232	/* Enable RX interrupts now */
	233	pp->imr = ALTERA_JTAGUART_CONTROL_RE_MSK;
	234	writel(pp->imr, port->membase + ALTERA_JTAGUART_CONTROL_REG);
	235
	236	spin_unlock_irqrestore(&port->lock, flags);
	237
	238	return 0;
	239	}
	240
	241	static void altera_jtaguart_shutdown(struct uart_port *port)
	242	{
	243	struct altera_jtaguart *pp =
	244	container_of(port, struct altera_jtaguart, port);
	245	unsigned long flags;
	246
	247	spin_lock_irqsave(&port->lock, flags);
	248
	249	/* Disable all interrupts now */
	250	pp->imr = 0;
	251	writel(pp->imr, port->membase + ALTERA_JTAGUART_CONTROL_REG);
	252
	253	spin_unlock_irqrestore(&port->lock, flags);
	254
	255	free_irq(port->irq, port);
	256	}
	257
	258	static const char altera_jtaguart_type(struct uart_port port)
	259	{
	260	return (port->type == PORT_ALTERA_JTAGUART) ? "Altera JTAG UART" : NULL;
	261	}
	262
	263	static int altera_jtaguart_request_port(struct uart_port *port)
	264	{
	265	/* UARTs always present */
	266	return 0;
	267	}
	268
	269	static void altera_jtaguart_release_port(struct uart_port *port)
	270	{
	271	/* Nothing to release... */
	272	}
	273
	274	static int altera_jtaguart_verify_port(struct uart_port *port,
	275	struct serial_struct *ser)
	276	{
	277	if (ser->type != PORT_UNKNOWN && ser->type != PORT_ALTERA_JTAGUART)
	278	return -EINVAL;
	279	return 0;
	280	}
	281
	282	/*
	283	* Define the basic serial functions we support.
	284	*/
	285	static struct uart_ops altera_jtaguart_ops = {
	286	.tx_empty = altera_jtaguart_tx_empty,
287	.get_mctrl = altera_jtaguart_get_mctrl,
288	.set_mctrl = altera_jtaguart_set_mctrl,
289	.start_tx = altera_jtaguart_start_tx,
290	.stop_tx = altera_jtaguart_stop_tx,
291	.stop_rx = altera_jtaguart_stop_rx,
292	.enable_ms = altera_jtaguart_enable_ms,
293	.break_ctl = altera_jtaguart_break_ctl,
294	.startup = altera_jtaguart_startup,
295	.shutdown = altera_jtaguart_shutdown,
296	.set_termios = altera_jtaguart_set_termios,
297	.type = altera_jtaguart_type,
298	.request_port = altera_jtaguart_request_port,
299	.release_port = altera_jtaguart_release_port,
300	.config_port = altera_jtaguart_config_port,
301	.verify_port = altera_jtaguart_verify_port,
302	};
303
304	#define ALTERA_JTAGUART_MAXPORTS 1
305	static struct altera_jtaguart altera_jtaguart_ports[ALTERA_JTAGUART_MAXPORTS];
306
307	#if defined(CONFIG_SERIAL_ALTERA_JTAGUART_CONSOLE)
308
5bcd6010 TK	309	#if defined(CONFIG_SERIAL_ALTERA_JTAGUART_CONSOLE_BYPASS)
	310	static void altera_jtaguart_console_putc(struct console *co, const char c)
	311	{
	312	struct uart_port *port = &(altera_jtaguart_ports + co->index)->port;
	313	unsigned long status;
	314	unsigned long flags;
	315
	316	spin_lock_irqsave(&port->lock, flags);
	317	while (((status = readl(port->membase + ALTERA_JTAGUART_CONTROL_REG)) &
	318	ALTERA_JTAGUART_CONTROL_WSPACE_MSK) == 0) {
	319	if ((status & ALTERA_JTAGUART_CONTROL_AC_MSK) == 0) {
	320	spin_unlock_irqrestore(&port->lock, flags);
	321	return; /* no connection activity */
	322	}
	323	spin_unlock_irqrestore(&port->lock, flags);
	324	cpu_relax();
	325	spin_lock_irqsave(&port->lock, flags);
	326	}
	327	writel(c, port->membase + ALTERA_JTAGUART_DATA_REG);
	328	spin_unlock_irqrestore(&port->lock, flags);
	329	}
	330	#else
	331	static void altera_jtaguart_console_putc(struct console *co, const char c)
	332	{
	333	struct uart_port *port = &(altera_jtaguart_ports + co->index)->port;
	334	unsigned long flags;
	335
	336	spin_lock_irqsave(&port->lock, flags);
	337	while ((readl(port->membase + ALTERA_JTAGUART_CONTROL_REG) &
	338	ALTERA_JTAGUART_CONTROL_WSPACE_MSK) == 0) {
	339	spin_unlock_irqrestore(&port->lock, flags);
	340	cpu_relax();
	341	spin_lock_irqsave(&port->lock, flags);
	342	}
	343	writel(c, port->membase + ALTERA_JTAGUART_DATA_REG);
	344	spin_unlock_irqrestore(&port->lock, flags);
	345	}
	346	#endif
	347
	348	static void altera_jtaguart_console_write(struct console co, const char s,
	349	unsigned int count)
	350	{
	351	for (; count; count--, s++) {
	352	altera_jtaguart_console_putc(co, *s);
	353	if (*s == '\n')
	354	altera_jtaguart_console_putc(co, '\r');
	355	}
	356	}
	357
	358	static int __init altera_jtaguart_console_setup(struct console *co,
	359	char *options)
	360	{
	361	struct uart_port *port;
	362
	363	if (co->index < 0 \|\| co->index >= ALTERA_JTAGUART_MAXPORTS)
	364	return -EINVAL;
	365	port = &altera_jtaguart_ports[co->index].port;
2314a0f6	366	if (port->membase == NULL)
5bcd6010 TK	367	return -ENODEV;
	368	return 0;
	369	}
	370
	371	static struct uart_driver altera_jtaguart_driver;
	372
	373	static struct console altera_jtaguart_console = {
	374	.name = "ttyJ",
	375	.write = altera_jtaguart_console_write,
	376	.device = uart_console_device,
	377	.setup = altera_jtaguart_console_setup,
	378	.flags = CON_PRINTBUFFER,
	379	.index = -1,
	380	.data = &altera_jtaguart_driver,
	381	};
	382
	383	static int __init altera_jtaguart_console_init(void)
	384	{
	385	register_console(&altera_jtaguart_console);
	386	return 0;
	387	}
	388
	389	console_initcall(altera_jtaguart_console_init);
	390
	391	#define ALTERA_JTAGUART_CONSOLE (&altera_jtaguart_console)
	392
	393	#else
	394
	395	#define ALTERA_JTAGUART_CONSOLE NULL
	396
	397	#endif /* CONFIG_ALTERA_JTAGUART_CONSOLE */
	398
	399	static struct uart_driver altera_jtaguart_driver = {
	400	.owner = THIS_MODULE,
	401	.driver_name = "altera_jtaguart",
	402	.dev_name = "ttyJ",
	403	.major = ALTERA_JTAGUART_MAJOR,
	404	.minor = ALTERA_JTAGUART_MINOR,
	405	.nr = ALTERA_JTAGUART_MAXPORTS,
	406	.cons = ALTERA_JTAGUART_CONSOLE,
	407	};
	408
9671f099	409	static int altera_jtaguart_probe(struct platform_device *pdev)
5bcd6010 TK	410	{
	411	struct altera_jtaguart_platform_uart *platp = pdev->dev.platform_data;
	412	struct uart_port *port;
72af4762 TK	413	struct resource res_irq, res_mem;
72af4762 TK	414	int i = pdev->id;
5bcd6010	415
72af4762 TK	416	/* -1 emphasizes that the platform must have one port, no .N suffix */
	417	if (i == -1)
	418	i = 0;
5bcd6010	419
72af4762 TK	420	if (i >= ALTERA_JTAGUART_MAXPORTS)
72af4762 TK	421	return -EINVAL;
5bcd6010	422
72af4762 TK	423	port = &altera_jtaguart_ports[i].port;
	424
	425	res_mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
	426	if (res_mem)
	427	port->mapbase = res_mem->start;
	428	else if (platp)
	429	port->mapbase = platp->mapbase;
	430	else
	431	return -ENODEV;
	432
	433	res_irq = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
	434	if (res_irq)
	435	port->irq = res_irq->start;
	436	else if (platp)
	437	port->irq = platp->irq;
	438	else
	439	return -ENODEV;
	440
	441	port->membase = ioremap(port->mapbase, ALTERA_JTAGUART_SIZE);
	442	if (!port->membase)
	443	return -ENOMEM;
	444
	445	port->line = i;
	446	port->type = PORT_ALTERA_JTAGUART;
	447	port->iotype = SERIAL_IO_MEM;
	448	port->ops = &altera_jtaguart_ops;
44ed76b7	449	port->flags = UPF_BOOT_AUTOCONF;
72af4762 TK	450
72af4762 TK	451	uart_add_one_port(&altera_jtaguart_driver, port);
5bcd6010 TK	452
	453	return 0;
	454	}
	455
ae8d8a14	456	static int altera_jtaguart_remove(struct platform_device *pdev)
5bcd6010 TK	457	{
5bcd6010 TK	458	struct uart_port *port;
72af4762	459	int i = pdev->id;
5bcd6010	460
72af4762 TK	461	if (i == -1)
	462	i = 0;
	463
	464	port = &altera_jtaguart_ports[i].port;
	465	uart_remove_one_port(&altera_jtaguart_driver, port);
5bcd6010 TK	466
	467	return 0;
	468	}
	469
9f15444f TK	470	#ifdef CONFIG_OF
	471	static struct of_device_id altera_jtaguart_match[] = {
	472	{ .compatible = "ALTR,juart-1.0", },
	473	{},
	474	};
	475	MODULE_DEVICE_TABLE(of, altera_jtaguart_match);
9f15444f TK	476	#endif /* CONFIG_OF */
9f15444f TK	477
5bcd6010 TK	478	static struct platform_driver altera_jtaguart_platform_driver = {
5bcd6010 TK	479	.probe = altera_jtaguart_probe,
2d47b716	480	.remove = altera_jtaguart_remove,
5bcd6010	481	.driver = {
9f15444f TK	482	.name = DRV_NAME,
9f15444f TK	483	.owner = THIS_MODULE,
85888069	484	.of_match_table = of_match_ptr(altera_jtaguart_match),
5bcd6010 TK	485	},
	486	};
	487
	488	static int __init altera_jtaguart_init(void)
	489	{
	490	int rc;
	491
	492	rc = uart_register_driver(&altera_jtaguart_driver);
	493	if (rc)
	494	return rc;
	495	rc = platform_driver_register(&altera_jtaguart_platform_driver);
	496	if (rc) {
	497	uart_unregister_driver(&altera_jtaguart_driver);
	498	return rc;
	499	}
	500	return 0;
	501	}
	502
	503	static void __exit altera_jtaguart_exit(void)
	504	{
	505	platform_driver_unregister(&altera_jtaguart_platform_driver);
	506	uart_unregister_driver(&altera_jtaguart_driver);
	507	}
	508
	509	module_init(altera_jtaguart_init);
	510	module_exit(altera_jtaguart_exit);
	511
	512	MODULE_DESCRIPTION("Altera JTAG UART driver");
	513	MODULE_AUTHOR("Thomas Chou <thomas@wytron.com.tw>");
	514	MODULE_LICENSE("GPL");
	515	MODULE_ALIAS("platform:" DRV_NAME);