[net-next-2.6.git] / drivers / 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/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.tty);
}

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, IRQF_DISABLED,
			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)

int __init early_altera_jtaguart_setup(struct altera_jtaguart_platform_uart
				       *platp)
{
	struct uart_port *port;
	int i;

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

		port->line = i;
		port->type = PORT_ALTERA_JTAGUART;
		port->mapbase = platp[i].mapbase;
		port->membase = ioremap(port->mapbase, ALTERA_JTAGUART_SIZE);
		port->iotype = SERIAL_IO_MEM;
		port->irq = platp[i].irq;
		port->flags = ASYNC_BOOT_AUTOCONF;
		port->ops = &altera_jtaguart_ops;
	}

	return 0;
}

#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 == 0)
		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 __devinit altera_jtaguart_probe(struct platform_device *pdev)
{
	struct altera_jtaguart_platform_uart *platp = pdev->dev.platform_data;
	struct uart_port *port;
	int i;

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

		port->line = i;
		port->type = PORT_ALTERA_JTAGUART;
		port->mapbase = platp[i].mapbase;
		port->membase = ioremap(port->mapbase, ALTERA_JTAGUART_SIZE);
		port->iotype = SERIAL_IO_MEM;
		port->irq = platp[i].irq;
		port->ops = &altera_jtaguart_ops;
		port->flags = ASYNC_BOOT_AUTOCONF;

		uart_add_one_port(&altera_jtaguart_driver, port);
	}

	return 0;
}

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

	for (i = 0; i < ALTERA_JTAGUART_MAXPORTS; i++) {
		port = &altera_jtaguart_ports[i].port;
		if (port)
			uart_remove_one_port(&altera_jtaguart_driver, port);
	}

	return 0;
}

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

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