[deliverable/linux.git] / drivers / serial / uartlite.c

/*
 * uartlite.c: Serial driver for Xilinx uartlite serial controller
 *
 * Copyright (C) 2006 Peter Korsgaard <jacmet@sunsite.dk>
 * Copyright (C) 2007 Secret Lab Technologies Ltd.
 *
 * This file is licensed under the terms of the GNU General Public License
 * version 2.  This program is licensed "as is" without any warranty of any
 * kind, whether express or implied.
 */

#include <linux/platform_device.h>
#include <linux/module.h>
#include <linux/console.h>
#include <linux/serial.h>
#include <linux/serial_core.h>
#include <linux/tty.h>
#include <linux/delay.h>
#include <linux/interrupt.h>
#include <asm/io.h>
#if defined(CONFIG_OF)
#include <linux/of_device.h>
#include <linux/of_platform.h>
#endif

#define ULITE_NAME		"ttyUL"
#define ULITE_MAJOR		204
#define ULITE_MINOR		187
#define ULITE_NR_UARTS		4

/* ---------------------------------------------------------------------
 * Register definitions
 *
 * For register details see datasheet:
 * http://www.xilinx.com/bvdocs/ipcenter/data_sheet/opb_uartlite.pdf
 */

#define ULITE_RX		0x00
#define ULITE_TX		0x04
#define ULITE_STATUS		0x08
#define ULITE_CONTROL		0x0c

#define ULITE_REGION		16

#define ULITE_STATUS_RXVALID	0x01
#define ULITE_STATUS_RXFULL	0x02
#define ULITE_STATUS_TXEMPTY	0x04
#define ULITE_STATUS_TXFULL	0x08
#define ULITE_STATUS_IE		0x10
#define ULITE_STATUS_OVERRUN	0x20
#define ULITE_STATUS_FRAME	0x40
#define ULITE_STATUS_PARITY	0x80

#define ULITE_CONTROL_RST_TX	0x01
#define ULITE_CONTROL_RST_RX	0x02
#define ULITE_CONTROL_IE	0x10


static struct uart_port ulite_ports[ULITE_NR_UARTS];

/* ---------------------------------------------------------------------
 * Core UART driver operations
 */

static int ulite_receive(struct uart_port *port, int stat)
{
	struct tty_struct *tty = port->info->tty;
	unsigned char ch = 0;
	char flag = TTY_NORMAL;

	if ((stat & (ULITE_STATUS_RXVALID | ULITE_STATUS_OVERRUN
		     | ULITE_STATUS_FRAME)) == 0)
		return 0;

	/* stats */
	if (stat & ULITE_STATUS_RXVALID) {
		port->icount.rx++;
		ch = in_be32((void*)port->membase + ULITE_RX);

		if (stat & ULITE_STATUS_PARITY)
			port->icount.parity++;
	}

	if (stat & ULITE_STATUS_OVERRUN)
		port->icount.overrun++;

	if (stat & ULITE_STATUS_FRAME)
		port->icount.frame++;


	/* drop byte with parity error if IGNPAR specificed */
	if (stat & port->ignore_status_mask & ULITE_STATUS_PARITY)
		stat &= ~ULITE_STATUS_RXVALID;

	stat &= port->read_status_mask;

	if (stat & ULITE_STATUS_PARITY)
		flag = TTY_PARITY;


	stat &= ~port->ignore_status_mask;

	if (stat & ULITE_STATUS_RXVALID)
		tty_insert_flip_char(tty, ch, flag);

	if (stat & ULITE_STATUS_FRAME)
		tty_insert_flip_char(tty, 0, TTY_FRAME);

	if (stat & ULITE_STATUS_OVERRUN)
		tty_insert_flip_char(tty, 0, TTY_OVERRUN);

	return 1;
}

static int ulite_transmit(struct uart_port *port, int stat)
{
	struct circ_buf *xmit  = &port->info->xmit;

	if (stat & ULITE_STATUS_TXFULL)
		return 0;

	if (port->x_char) {
		out_be32((void*)port->membase + ULITE_TX, port->x_char);
		port->x_char = 0;
		port->icount.tx++;
		return 1;
	}

	if (uart_circ_empty(xmit) || uart_tx_stopped(port))
		return 0;

	out_be32((void*)port->membase + ULITE_TX, xmit->buf[xmit->tail]);
	xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE-1);
	port->icount.tx++;

	/* wake up */
	if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
		uart_write_wakeup(port);

	return 1;
}

static irqreturn_t ulite_isr(int irq, void *dev_id)
{
	struct uart_port *port = (struct uart_port *)dev_id;
	int busy;

	do {
		int stat = in_be32((void*)port->membase + ULITE_STATUS);
		busy  = ulite_receive(port, stat);
		busy |= ulite_transmit(port, stat);
	} while (busy);

	tty_flip_buffer_push(port->info->tty);

	return IRQ_HANDLED;
}

static unsigned int ulite_tx_empty(struct uart_port *port)
{
	unsigned long flags;
	unsigned int ret;

	spin_lock_irqsave(&port->lock, flags);
	ret = in_be32((void*)port->membase + ULITE_STATUS);
	spin_unlock_irqrestore(&port->lock, flags);

	return ret & ULITE_STATUS_TXEMPTY ? TIOCSER_TEMT : 0;
}

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

static void ulite_set_mctrl(struct uart_port *port, unsigned int mctrl)
{
	/* N/A */
}

static void ulite_stop_tx(struct uart_port *port)
{
	/* N/A */
}

static void ulite_start_tx(struct uart_port *port)
{
	ulite_transmit(port, in_be32((void*)port->membase + ULITE_STATUS));
}

static void ulite_stop_rx(struct uart_port *port)
{
	/* don't forward any more data (like !CREAD) */
	port->ignore_status_mask = ULITE_STATUS_RXVALID | ULITE_STATUS_PARITY
		| ULITE_STATUS_FRAME | ULITE_STATUS_OVERRUN;
}

static void ulite_enable_ms(struct uart_port *port)
{
	/* N/A */
}

static void ulite_break_ctl(struct uart_port *port, int ctl)
{
	/* N/A */
}

static int ulite_startup(struct uart_port *port)
{
	int ret;

	ret = request_irq(port->irq, ulite_isr,
			  IRQF_DISABLED | IRQF_SAMPLE_RANDOM, "uartlite", port);
	if (ret)
		return ret;

	out_be32((void*)port->membase + ULITE_CONTROL,
	         ULITE_CONTROL_RST_RX | ULITE_CONTROL_RST_TX);
	out_be32((void*)port->membase + ULITE_CONTROL, ULITE_CONTROL_IE);

	return 0;
}

static void ulite_shutdown(struct uart_port *port)
{
	out_be32((void*)port->membase + ULITE_CONTROL, 0);
	in_be32((void*)port->membase + ULITE_CONTROL); /* dummy */
	free_irq(port->irq, port);
}

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

	spin_lock_irqsave(&port->lock, flags);

	port->read_status_mask = ULITE_STATUS_RXVALID | ULITE_STATUS_OVERRUN
		| ULITE_STATUS_TXFULL;

	if (termios->c_iflag & INPCK)
		port->read_status_mask |=
			ULITE_STATUS_PARITY | ULITE_STATUS_FRAME;

	port->ignore_status_mask = 0;
	if (termios->c_iflag & IGNPAR)
		port->ignore_status_mask |= ULITE_STATUS_PARITY
			| ULITE_STATUS_FRAME | ULITE_STATUS_OVERRUN;

	/* ignore all characters if CREAD is not set */
	if ((termios->c_cflag & CREAD) == 0)
		port->ignore_status_mask |=
			ULITE_STATUS_RXVALID | ULITE_STATUS_PARITY
			| ULITE_STATUS_FRAME | ULITE_STATUS_OVERRUN;

	/* update timeout */
	baud = uart_get_baud_rate(port, termios, old, 0, 460800);
	uart_update_timeout(port, termios->c_cflag, baud);

	spin_unlock_irqrestore(&port->lock, flags);
}

static const char *ulite_type(struct uart_port *port)
{
	return port->type == PORT_UARTLITE ? "uartlite" : NULL;
}

static void ulite_release_port(struct uart_port *port)
{
	release_mem_region(port->mapbase, ULITE_REGION);
	iounmap(port->membase);
	port->membase = NULL;
}

static int ulite_request_port(struct uart_port *port)
{
	if (!request_mem_region(port->mapbase, ULITE_REGION, "uartlite")) {
		dev_err(port->dev, "Memory region busy\n");
		return -EBUSY;
	}

	port->membase = ioremap(port->mapbase, ULITE_REGION);
	if (!port->membase) {
		dev_err(port->dev, "Unable to map registers\n");
		release_mem_region(port->mapbase, ULITE_REGION);
		return -EBUSY;
	}

	return 0;
}

static void ulite_config_port(struct uart_port *port, int flags)
{
	if (!ulite_request_port(port))
		port->type = PORT_UARTLITE;
}

static int ulite_verify_port(struct uart_port *port, struct serial_struct *ser)
{
	/* we don't want the core code to modify any port params */
	return -EINVAL;
}

static struct uart_ops ulite_ops = {
	.tx_empty	= ulite_tx_empty,
	.set_mctrl	= ulite_set_mctrl,
	.get_mctrl	= ulite_get_mctrl,
	.stop_tx	= ulite_stop_tx,
	.start_tx	= ulite_start_tx,
	.stop_rx	= ulite_stop_rx,
	.enable_ms	= ulite_enable_ms,
	.break_ctl	= ulite_break_ctl,
	.startup	= ulite_startup,
	.shutdown	= ulite_shutdown,
	.set_termios	= ulite_set_termios,
	.type		= ulite_type,
	.release_port	= ulite_release_port,
	.request_port	= ulite_request_port,
	.config_port	= ulite_config_port,
	.verify_port	= ulite_verify_port
};

/* ---------------------------------------------------------------------
 * Console driver operations
 */

#ifdef CONFIG_SERIAL_UARTLITE_CONSOLE
static void ulite_console_wait_tx(struct uart_port *port)
{
	int i;

	/* wait up to 10ms for the character(s) to be sent */
	for (i = 0; i < 10000; i++) {
		if (in_be32((void*)port->membase + ULITE_STATUS) & ULITE_STATUS_TXEMPTY)
			break;
		udelay(1);
	}
}

static void ulite_console_putchar(struct uart_port *port, int ch)
{
	ulite_console_wait_tx(port);
	out_be32((void*)port->membase + ULITE_TX, ch);
}

static void ulite_console_write(struct console *co, const char *s,
				unsigned int count)
{
	struct uart_port *port = &ulite_ports[co->index];
	unsigned long flags;
	unsigned int ier;
	int locked = 1;

	if (oops_in_progress) {
		locked = spin_trylock_irqsave(&port->lock, flags);
	} else
		spin_lock_irqsave(&port->lock, flags);

	/* save and disable interrupt */
	ier = in_be32((void*)port->membase + ULITE_STATUS) & ULITE_STATUS_IE;
	out_be32((void*)port->membase + ULITE_CONTROL, 0);

	uart_console_write(port, s, count, ulite_console_putchar);

	ulite_console_wait_tx(port);

	/* restore interrupt state */
	if (ier)
		out_be32((void*)port->membase + ULITE_CONTROL, ULITE_CONTROL_IE);

	if (locked)
		spin_unlock_irqrestore(&port->lock, flags);
}

#if defined(CONFIG_OF)
static inline void __init ulite_console_of_find_device(int id)
{
	struct device_node *np;
	struct resource res;
	const unsigned int *of_id;
	int rc;

	for_each_compatible_node(np, NULL, "xilinx,uartlite") {
		of_id = of_get_property(np, "port-number", NULL);
		if ((!of_id) || (*of_id != id))
			continue;

		rc = of_address_to_resource(np, 0, &res);
		if (rc)
			continue;

		ulite_ports[id].mapbase = res.start;
		return;
	}
}
#else /* CONFIG_OF */
static inline void __init ulite_console_of_find_device(int id) { /* do nothing */ }
#endif /* CONFIG_OF */

static int __init ulite_console_setup(struct console *co, char *options)
{
	struct uart_port *port;
	int baud = 9600;
	int bits = 8;
	int parity = 'n';
	int flow = 'n';

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

	port = &ulite_ports[co->index];

	/* Check if it is an OF device */
	if (!port->mapbase)
		ulite_console_of_find_device(co->index);

	/* Do we have a device now? */
	if (!port->mapbase) {
		pr_debug("console on ttyUL%i not present\n", co->index);
		return -ENODEV;
	}

	/* not initialized yet? */
	if (!port->membase) {
		if (ulite_request_port(port))
			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 ulite_uart_driver;

static struct console ulite_console = {
	.name	= ULITE_NAME,
	.write	= ulite_console_write,
	.device	= uart_console_device,
	.setup	= ulite_console_setup,
	.flags	= CON_PRINTBUFFER,
	.index	= -1, /* Specified on the cmdline (e.g. console=ttyUL0 ) */
	.data	= &ulite_uart_driver,
};

static int __init ulite_console_init(void)
{
	register_console(&ulite_console);
	return 0;
}

console_initcall(ulite_console_init);

#endif /* CONFIG_SERIAL_UARTLITE_CONSOLE */

static struct uart_driver ulite_uart_driver = {
	.owner		= THIS_MODULE,
	.driver_name	= "uartlite",
	.dev_name	= ULITE_NAME,
	.major		= ULITE_MAJOR,
	.minor		= ULITE_MINOR,
	.nr		= ULITE_NR_UARTS,
#ifdef CONFIG_SERIAL_UARTLITE_CONSOLE
	.cons		= &ulite_console,
#endif
};

/* ---------------------------------------------------------------------
 * Port assignment functions (mapping devices to uart_port structures)
 */

/** ulite_assign: register a uartlite device with the driver
 *
 * @dev: pointer to device structure
 * @id: requested id number.  Pass -1 for automatic port assignment
 * @base: base address of uartlite registers
 * @irq: irq number for uartlite
 *
 * Returns: 0 on success, <0 otherwise
 */
static int __devinit ulite_assign(struct device *dev, int id, u32 base, int irq)
{
	struct uart_port *port;
	int rc;

	/* if id = -1; then scan for a free id and use that */
	if (id < 0) {
		for (id = 0; id < ULITE_NR_UARTS; id++)
			if (ulite_ports[id].mapbase == 0)
				break;
	}
	if (id < 0 || id >= ULITE_NR_UARTS) {
		dev_err(dev, "%s%i too large\n", ULITE_NAME, id);
		return -EINVAL;
	}

	if ((ulite_ports[id].mapbase) && (ulite_ports[id].mapbase != base)) {
		dev_err(dev, "cannot assign to %s%i; it is already in use\n",
			ULITE_NAME, id);
		return -EBUSY;
	}

	port = &ulite_ports[id];

	spin_lock_init(&port->lock);
	port->fifosize = 16;
	port->regshift = 2;
	port->iotype = UPIO_MEM;
	port->iobase = 1; /* mark port in use */
	port->mapbase = base;
	port->membase = NULL;
	port->ops = &ulite_ops;
	port->irq = irq;
	port->flags = UPF_BOOT_AUTOCONF;
	port->dev = dev;
	port->type = PORT_UNKNOWN;
	port->line = id;

	dev_set_drvdata(dev, port);

	/* Register the port */
	rc = uart_add_one_port(&ulite_uart_driver, port);
	if (rc) {
		dev_err(dev, "uart_add_one_port() failed; err=%i\n", rc);
		port->mapbase = 0;
		dev_set_drvdata(dev, NULL);
		return rc;
	}

	return 0;
}

/** ulite_release: register a uartlite device with the driver
 *
 * @dev: pointer to device structure
 */
static int __devinit ulite_release(struct device *dev)
{
	struct uart_port *port = dev_get_drvdata(dev);
	int rc = 0;

	if (port) {
		rc = uart_remove_one_port(&ulite_uart_driver, port);
		dev_set_drvdata(dev, NULL);
		port->mapbase = 0;
	}

	return rc;
}

/* ---------------------------------------------------------------------
 * Platform bus binding
 */

static int __devinit ulite_probe(struct platform_device *pdev)
{
	struct resource *res, *res2;

	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
	if (!res)
		return -ENODEV;

	res2 = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
	if (!res2)
		return -ENODEV;

	return ulite_assign(&pdev->dev, pdev->id, res->start, res2->start);
}

static int ulite_remove(struct platform_device *pdev)
{
	return ulite_release(&pdev->dev);
}

static struct platform_driver ulite_platform_driver = {
	.probe	= ulite_probe,
	.remove	= ulite_remove,
	.driver	= {
		   .owner = THIS_MODULE,
		   .name  = "uartlite",
		   },
};

/* ---------------------------------------------------------------------
 * OF bus bindings
 */
#if defined(CONFIG_OF)
static int __devinit
ulite_of_probe(struct of_device *op, const struct of_device_id *match)
{
	struct resource res;
	const unsigned int *id;
	int irq, rc;

	dev_dbg(&op->dev, "%s(%p, %p)\n", __FUNCTION__, op, match);

	rc = of_address_to_resource(op->node, 0, &res);
	if (rc) {
		dev_err(&op->dev, "invalide address\n");
		return rc;
	}

	irq = irq_of_parse_and_map(op->node, 0);

	id = of_get_property(op->node, "port-number", NULL);

	return ulite_assign(&op->dev, id ? *id : -1, res.start, irq);
}

static int __devexit ulite_of_remove(struct of_device *op)
{
	return ulite_release(&op->dev);
}

/* Match table for of_platform binding */
static struct of_device_id __devinit ulite_of_match[] = {
	{ .type = "serial", .compatible = "xilinx,uartlite", },
	{},
};
MODULE_DEVICE_TABLE(of, ulite_of_match);

static struct of_platform_driver ulite_of_driver = {
	.owner = THIS_MODULE,
	.name = "uartlite",
	.match_table = ulite_of_match,
	.probe = ulite_of_probe,
	.remove = __devexit_p(ulite_of_remove),
	.driver = {
		.name = "uartlite",
	},
};

/* Registration helpers to keep the number of #ifdefs to a minimum */
static inline int __init ulite_of_register(void)
{
	pr_debug("uartlite: calling of_register_platform_driver()\n");
	return of_register_platform_driver(&ulite_of_driver);
}

static inline void __exit ulite_of_unregister(void)
{
	of_unregister_platform_driver(&ulite_of_driver);
}
#else /* CONFIG_OF */
/* CONFIG_OF not enabled; do nothing helpers */
static inline int __init ulite_of_register(void) { return 0; }
static inline void __exit ulite_of_unregister(void) { }
#endif /* CONFIG_OF */

/* ---------------------------------------------------------------------
 * Module setup/teardown
 */

int __init ulite_init(void)
{
	int ret;

	pr_debug("uartlite: calling uart_register_driver()\n");
	ret = uart_register_driver(&ulite_uart_driver);
	if (ret)
		goto err_uart;

	ret = ulite_of_register();
	if (ret)
		goto err_of;

	pr_debug("uartlite: calling platform_driver_register()\n");
	ret = platform_driver_register(&ulite_platform_driver);
	if (ret)
		goto err_plat;

	return 0;

err_plat:
	ulite_of_unregister();
err_of:
	uart_unregister_driver(&ulite_uart_driver);
err_uart:
	printk(KERN_ERR "registering uartlite driver failed: err=%i", ret);
	return ret;
}

void __exit ulite_exit(void)
{
	platform_driver_unregister(&ulite_platform_driver);
	ulite_of_unregister();
	uart_unregister_driver(&ulite_uart_driver);
}

module_init(ulite_init);
module_exit(ulite_exit);

MODULE_AUTHOR("Peter Korsgaard <jacmet@sunsite.dk>");
MODULE_DESCRIPTION("Xilinx uartlite serial driver");
MODULE_LICENSE("GPL");
Commit	Line	Data
238b8721 PK	1	/*
	2	* uartlite.c: Serial driver for Xilinx uartlite serial controller
	3	*
852e1ea7 GL	4	* Copyright (C) 2006 Peter Korsgaard <jacmet@sunsite.dk>
852e1ea7 GL	5	* Copyright (C) 2007 Secret Lab Technologies Ltd.
238b8721 PK	6	*
	7	* This file is licensed under the terms of the GNU General Public License
	8	* version 2. This program is licensed "as is" without any warranty of any
	9	* kind, whether express or implied.
	10	*/
	11
	12	#include <linux/platform_device.h>
	13	#include <linux/module.h>
	14	#include <linux/console.h>
	15	#include <linux/serial.h>
	16	#include <linux/serial_core.h>
	17	#include <linux/tty.h>
	18	#include <linux/delay.h>
	19	#include <linux/interrupt.h>
	20	#include <asm/io.h>
852e1ea7 GL	21	#if defined(CONFIG_OF)
	22	#include <linux/of_device.h>
	23	#include <linux/of_platform.h>
	24	#endif
238b8721	25
00775828	26	#define ULITE_NAME "ttyUL"
238b8721 PK	27	#define ULITE_MAJOR 204
	28	#define ULITE_MINOR 187
	29	#define ULITE_NR_UARTS 4
	30
435706b3 GL	31	/* ---------------------------------------------------------------------
	32	* Register definitions
	33	*
	34	* For register details see datasheet:
	35	* http://www.xilinx.com/bvdocs/ipcenter/data_sheet/opb_uartlite.pdf
	36	*/
	37
238b8721 PK	38	#define ULITE_RX 0x00
	39	#define ULITE_TX 0x04
	40	#define ULITE_STATUS 0x08
	41	#define ULITE_CONTROL 0x0c
	42
	43	#define ULITE_REGION 16
	44
	45	#define ULITE_STATUS_RXVALID 0x01
	46	#define ULITE_STATUS_RXFULL 0x02
	47	#define ULITE_STATUS_TXEMPTY 0x04
	48	#define ULITE_STATUS_TXFULL 0x08
	49	#define ULITE_STATUS_IE 0x10
	50	#define ULITE_STATUS_OVERRUN 0x20
	51	#define ULITE_STATUS_FRAME 0x40
	52	#define ULITE_STATUS_PARITY 0x80
	53
	54	#define ULITE_CONTROL_RST_TX 0x01
	55	#define ULITE_CONTROL_RST_RX 0x02
	56	#define ULITE_CONTROL_IE 0x10
	57
	58
483c79db	59	static struct uart_port ulite_ports[ULITE_NR_UARTS];
238b8721	60
435706b3 GL	61	/* ---------------------------------------------------------------------
	62	* Core UART driver operations
	63	*/
	64
238b8721 PK	65	static int ulite_receive(struct uart_port *port, int stat)
	66	{
	67	struct tty_struct *tty = port->info->tty;
	68	unsigned char ch = 0;
	69	char flag = TTY_NORMAL;
	70
	71	if ((stat & (ULITE_STATUS_RXVALID \| ULITE_STATUS_OVERRUN
	72	\| ULITE_STATUS_FRAME)) == 0)
	73	return 0;
	74
	75	/* stats */
	76	if (stat & ULITE_STATUS_RXVALID) {
	77	port->icount.rx++;
a15da8ef	78	ch = in_be32((void*)port->membase + ULITE_RX);
238b8721 PK	79
	80	if (stat & ULITE_STATUS_PARITY)
	81	port->icount.parity++;
	82	}
	83
	84	if (stat & ULITE_STATUS_OVERRUN)
	85	port->icount.overrun++;
	86
	87	if (stat & ULITE_STATUS_FRAME)
	88	port->icount.frame++;
	89
	90
	91	/* drop byte with parity error if IGNPAR specificed */
	92	if (stat & port->ignore_status_mask & ULITE_STATUS_PARITY)
	93	stat &= ~ULITE_STATUS_RXVALID;
	94
	95	stat &= port->read_status_mask;
	96
	97	if (stat & ULITE_STATUS_PARITY)
	98	flag = TTY_PARITY;
	99
	100
	101	stat &= ~port->ignore_status_mask;
	102
	103	if (stat & ULITE_STATUS_RXVALID)
	104	tty_insert_flip_char(tty, ch, flag);
	105
	106	if (stat & ULITE_STATUS_FRAME)
	107	tty_insert_flip_char(tty, 0, TTY_FRAME);
	108
	109	if (stat & ULITE_STATUS_OVERRUN)
	110	tty_insert_flip_char(tty, 0, TTY_OVERRUN);
	111
	112	return 1;
	113	}
	114
	115	static int ulite_transmit(struct uart_port *port, int stat)
	116	{
	117	struct circ_buf *xmit = &port->info->xmit;
	118
	119	if (stat & ULITE_STATUS_TXFULL)
	120	return 0;
	121
	122	if (port->x_char) {
a15da8ef	123	out_be32((void*)port->membase + ULITE_TX, port->x_char);
238b8721 PK	124	port->x_char = 0;
	125	port->icount.tx++;
	126	return 1;
	127	}
	128
	129	if (uart_circ_empty(xmit) \|\| uart_tx_stopped(port))
	130	return 0;
	131
a15da8ef	132	out_be32((void*)port->membase + ULITE_TX, xmit->buf[xmit->tail]);
238b8721 PK	133	xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE-1);
	134	port->icount.tx++;
	135
	136	/* wake up */
	137	if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
	138	uart_write_wakeup(port);
	139
	140	return 1;
	141	}
	142
	143	static irqreturn_t ulite_isr(int irq, void *dev_id)
	144	{
	145	struct uart_port port = (struct uart_port )dev_id;
	146	int busy;
	147
	148	do {
a15da8ef	149	int stat = in_be32((void*)port->membase + ULITE_STATUS);
238b8721 PK	150	busy = ulite_receive(port, stat);
	151	busy \|= ulite_transmit(port, stat);
	152	} while (busy);
	153
	154	tty_flip_buffer_push(port->info->tty);
	155
	156	return IRQ_HANDLED;
	157	}
	158
	159	static unsigned int ulite_tx_empty(struct uart_port *port)
	160	{
	161	unsigned long flags;
	162	unsigned int ret;
	163
	164	spin_lock_irqsave(&port->lock, flags);
a15da8ef	165	ret = in_be32((void*)port->membase + ULITE_STATUS);
238b8721 PK	166	spin_unlock_irqrestore(&port->lock, flags);
	167
	168	return ret & ULITE_STATUS_TXEMPTY ? TIOCSER_TEMT : 0;
	169	}
	170
	171	static unsigned int ulite_get_mctrl(struct uart_port *port)
	172	{
	173	return TIOCM_CTS \| TIOCM_DSR \| TIOCM_CAR;
	174	}
	175
	176	static void ulite_set_mctrl(struct uart_port *port, unsigned int mctrl)
	177	{
	178	/* N/A */
	179	}
	180
	181	static void ulite_stop_tx(struct uart_port *port)
	182	{
	183	/* N/A */
	184	}
	185
	186	static void ulite_start_tx(struct uart_port *port)
	187	{
a15da8ef	188	ulite_transmit(port, in_be32((void*)port->membase + ULITE_STATUS));
238b8721 PK	189	}
	190
	191	static void ulite_stop_rx(struct uart_port *port)
	192	{
	193	/* don't forward any more data (like !CREAD) */
	194	port->ignore_status_mask = ULITE_STATUS_RXVALID \| ULITE_STATUS_PARITY
	195	\| ULITE_STATUS_FRAME \| ULITE_STATUS_OVERRUN;
	196	}
	197
	198	static void ulite_enable_ms(struct uart_port *port)
	199	{
	200	/* N/A */
	201	}
	202
	203	static void ulite_break_ctl(struct uart_port *port, int ctl)
	204	{
	205	/* N/A */
	206	}
	207
	208	static int ulite_startup(struct uart_port *port)
	209	{
	210	int ret;
	211
	212	ret = request_irq(port->irq, ulite_isr,
	213	IRQF_DISABLED \| IRQF_SAMPLE_RANDOM, "uartlite", port);
	214	if (ret)
	215	return ret;
	216
a15da8ef GL	217	out_be32((void*)port->membase + ULITE_CONTROL,
	218	ULITE_CONTROL_RST_RX \| ULITE_CONTROL_RST_TX);
	219	out_be32((void*)port->membase + ULITE_CONTROL, ULITE_CONTROL_IE);
238b8721 PK	220
	221	return 0;
	222	}
	223
	224	static void ulite_shutdown(struct uart_port *port)
	225	{
a15da8ef GL	226	out_be32((void*)port->membase + ULITE_CONTROL, 0);
a15da8ef GL	227	in_be32((void)port->membase + ULITE_CONTROL); / dummy */
238b8721 PK	228	free_irq(port->irq, port);
	229	}
	230
606d099c AC	231	static void ulite_set_termios(struct uart_port port, struct ktermios termios,
606d099c AC	232	struct ktermios *old)
238b8721 PK	233	{
	234	unsigned long flags;
	235	unsigned int baud;
	236
	237	spin_lock_irqsave(&port->lock, flags);
	238
	239	port->read_status_mask = ULITE_STATUS_RXVALID \| ULITE_STATUS_OVERRUN
	240	\| ULITE_STATUS_TXFULL;
	241
	242	if (termios->c_iflag & INPCK)
	243	port->read_status_mask \|=
	244	ULITE_STATUS_PARITY \| ULITE_STATUS_FRAME;
	245
	246	port->ignore_status_mask = 0;
	247	if (termios->c_iflag & IGNPAR)
	248	port->ignore_status_mask \|= ULITE_STATUS_PARITY
	249	\| ULITE_STATUS_FRAME \| ULITE_STATUS_OVERRUN;
	250
	251	/* ignore all characters if CREAD is not set */
	252	if ((termios->c_cflag & CREAD) == 0)
	253	port->ignore_status_mask \|=
	254	ULITE_STATUS_RXVALID \| ULITE_STATUS_PARITY
	255	\| ULITE_STATUS_FRAME \| ULITE_STATUS_OVERRUN;
	256
	257	/* update timeout */
	258	baud = uart_get_baud_rate(port, termios, old, 0, 460800);
	259	uart_update_timeout(port, termios->c_cflag, baud);
	260
	261	spin_unlock_irqrestore(&port->lock, flags);
	262	}
	263
	264	static const char ulite_type(struct uart_port port)
	265	{
	266	return port->type == PORT_UARTLITE ? "uartlite" : NULL;
	267	}
	268
	269	static void ulite_release_port(struct uart_port *port)
	270	{
	271	release_mem_region(port->mapbase, ULITE_REGION);
	272	iounmap(port->membase);
b81831c6	273	port->membase = NULL;
238b8721 PK	274	}
	275
	276	static int ulite_request_port(struct uart_port *port)
	277	{
	278	if (!request_mem_region(port->mapbase, ULITE_REGION, "uartlite")) {
	279	dev_err(port->dev, "Memory region busy\n");
	280	return -EBUSY;
	281	}
	282
	283	port->membase = ioremap(port->mapbase, ULITE_REGION);
	284	if (!port->membase) {
	285	dev_err(port->dev, "Unable to map registers\n");
	286	release_mem_region(port->mapbase, ULITE_REGION);
	287	return -EBUSY;
	288	}
	289
	290	return 0;
	291	}
	292
	293	static void ulite_config_port(struct uart_port *port, int flags)
	294	{
e21654a7 PK	295	if (!ulite_request_port(port))
e21654a7 PK	296	port->type = PORT_UARTLITE;
238b8721 PK	297	}
	298
	299	static int ulite_verify_port(struct uart_port port, struct serial_struct ser)
	300	{
	301	/* we don't want the core code to modify any port params */
	302	return -EINVAL;
	303	}
	304
	305	static struct uart_ops ulite_ops = {
	306	.tx_empty = ulite_tx_empty,
	307	.set_mctrl = ulite_set_mctrl,
	308	.get_mctrl = ulite_get_mctrl,
	309	.stop_tx = ulite_stop_tx,
	310	.start_tx = ulite_start_tx,
	311	.stop_rx = ulite_stop_rx,
	312	.enable_ms = ulite_enable_ms,
	313	.break_ctl = ulite_break_ctl,
	314	.startup = ulite_startup,
	315	.shutdown = ulite_shutdown,
	316	.set_termios = ulite_set_termios,
	317	.type = ulite_type,
	318	.release_port = ulite_release_port,
	319	.request_port = ulite_request_port,
	320	.config_port = ulite_config_port,
	321	.verify_port = ulite_verify_port
	322	};
	323
435706b3 GL	324	/* ---------------------------------------------------------------------
	325	* Console driver operations
	326	*/
	327
238b8721 PK	328	#ifdef CONFIG_SERIAL_UARTLITE_CONSOLE
	329	static void ulite_console_wait_tx(struct uart_port *port)
	330	{
	331	int i;
	332
	333	/* wait up to 10ms for the character(s) to be sent */
	334	for (i = 0; i < 10000; i++) {
a15da8ef	335	if (in_be32((void*)port->membase + ULITE_STATUS) & ULITE_STATUS_TXEMPTY)
238b8721 PK	336	break;
	337	udelay(1);
	338	}
	339	}
	340
	341	static void ulite_console_putchar(struct uart_port *port, int ch)
	342	{
	343	ulite_console_wait_tx(port);
a15da8ef	344	out_be32((void*)port->membase + ULITE_TX, ch);
238b8721 PK	345	}
	346
	347	static void ulite_console_write(struct console co, const char s,
	348	unsigned int count)
	349	{
483c79db	350	struct uart_port *port = &ulite_ports[co->index];
238b8721 PK	351	unsigned long flags;
	352	unsigned int ier;
	353	int locked = 1;
	354
	355	if (oops_in_progress) {
	356	locked = spin_trylock_irqsave(&port->lock, flags);
	357	} else
	358	spin_lock_irqsave(&port->lock, flags);
	359
	360	/* save and disable interrupt */
a15da8ef GL	361	ier = in_be32((void*)port->membase + ULITE_STATUS) & ULITE_STATUS_IE;
a15da8ef GL	362	out_be32((void*)port->membase + ULITE_CONTROL, 0);
238b8721 PK	363
	364	uart_console_write(port, s, count, ulite_console_putchar);
	365
	366	ulite_console_wait_tx(port);
	367
	368	/* restore interrupt state */
	369	if (ier)
a15da8ef	370	out_be32((void*)port->membase + ULITE_CONTROL, ULITE_CONTROL_IE);
238b8721 PK	371
	372	if (locked)
	373	spin_unlock_irqrestore(&port->lock, flags);
	374	}
	375
fb4e6e66 GL	376	#if defined(CONFIG_OF)
	377	static inline void __init ulite_console_of_find_device(int id)
	378	{
	379	struct device_node *np;
	380	struct resource res;
	381	const unsigned int *of_id;
	382	int rc;
	383
	384	for_each_compatible_node(np, NULL, "xilinx,uartlite") {
	385	of_id = of_get_property(np, "port-number", NULL);
	386	if ((!of_id) \|\| (*of_id != id))
	387	continue;
	388
	389	rc = of_address_to_resource(np, 0, &res);
	390	if (rc)
	391	continue;
	392
	393	ulite_ports[id].mapbase = res.start;
	394	return;
	395	}
	396	}
	397	#else /* CONFIG_OF */
	398	static inline void __init ulite_console_of_find_device(int id) { /* do nothing */ }
	399	#endif /* CONFIG_OF */
	400
238b8721 PK	401	static int __init ulite_console_setup(struct console co, char options)
	402	{
	403	struct uart_port *port;
	404	int baud = 9600;
	405	int bits = 8;
	406	int parity = 'n';
	407	int flow = 'n';
	408
	409	if (co->index < 0 \|\| co->index >= ULITE_NR_UARTS)
	410	return -EINVAL;
	411
483c79db	412	port = &ulite_ports[co->index];
238b8721	413
fb4e6e66 GL	414	/* Check if it is an OF device */
	415	if (!port->mapbase)
	416	ulite_console_of_find_device(co->index);
	417
	418	/* Do we have a device now? */
	419	if (!port->mapbase) {
	420	pr_debug("console on ttyUL%i not present\n", co->index);
	421	return -ENODEV;
	422	}
	423
238b8721	424	/* not initialized yet? */
852e1ea7	425	if (!port->membase) {
fb4e6e66 GL	426	if (ulite_request_port(port))
fb4e6e66 GL	427	return -ENODEV;
852e1ea7	428	}
238b8721 PK	429
	430	if (options)
	431	uart_parse_options(options, &baud, &parity, &bits, &flow);
	432
	433	return uart_set_options(port, co, baud, parity, bits, flow);
	434	}
	435
	436	static struct uart_driver ulite_uart_driver;
	437
	438	static struct console ulite_console = {
00775828	439	.name = ULITE_NAME,
238b8721 PK	440	.write = ulite_console_write,
	441	.device = uart_console_device,
	442	.setup = ulite_console_setup,
	443	.flags = CON_PRINTBUFFER,
	444	.index = -1, /* Specified on the cmdline (e.g. console=ttyUL0 ) */
	445	.data = &ulite_uart_driver,
	446	};
	447
	448	static int __init ulite_console_init(void)
	449	{
	450	register_console(&ulite_console);
	451	return 0;
	452	}
	453
	454	console_initcall(ulite_console_init);
	455
	456	#endif /* CONFIG_SERIAL_UARTLITE_CONSOLE */
	457
	458	static struct uart_driver ulite_uart_driver = {
	459	.owner = THIS_MODULE,
	460	.driver_name = "uartlite",
00775828	461	.dev_name = ULITE_NAME,
238b8721 PK	462	.major = ULITE_MAJOR,
	463	.minor = ULITE_MINOR,
	464	.nr = ULITE_NR_UARTS,
	465	#ifdef CONFIG_SERIAL_UARTLITE_CONSOLE
	466	.cons = &ulite_console,
	467	#endif
	468	};
	469
435706b3 GL	470	/* ---------------------------------------------------------------------
	471	* Port assignment functions (mapping devices to uart_port structures)
	472	*/
	473
	474	/** ulite_assign: register a uartlite device with the driver
	475	*
	476	* @dev: pointer to device structure
	477	* @id: requested id number. Pass -1 for automatic port assignment
	478	* @base: base address of uartlite registers
	479	* @irq: irq number for uartlite
	480	*
	481	* Returns: 0 on success, <0 otherwise
	482	*/
8fa7b610	483	static int __devinit ulite_assign(struct device *dev, int id, u32 base, int irq)
238b8721	484	{
238b8721	485	struct uart_port *port;
8fa7b610	486	int rc;
238b8721	487
8fa7b610 GL	488	/* if id = -1; then scan for a free id and use that */
	489	if (id < 0) {
	490	for (id = 0; id < ULITE_NR_UARTS; id++)
	491	if (ulite_ports[id].mapbase == 0)
	492	break;
	493	}
	494	if (id < 0 \|\| id >= ULITE_NR_UARTS) {
	495	dev_err(dev, "%s%i too large\n", ULITE_NAME, id);
238b8721	496	return -EINVAL;
8fa7b610	497	}
238b8721	498
fb4e6e66	499	if ((ulite_ports[id].mapbase) && (ulite_ports[id].mapbase != base)) {
8fa7b610 GL	500	dev_err(dev, "cannot assign to %s%i; it is already in use\n",
8fa7b610 GL	501	ULITE_NAME, id);
238b8721	502	return -EBUSY;
8fa7b610	503	}
238b8721	504
8fa7b610	505	port = &ulite_ports[id];
238b8721	506
8fa7b610 GL	507	spin_lock_init(&port->lock);
	508	port->fifosize = 16;
	509	port->regshift = 2;
	510	port->iotype = UPIO_MEM;
	511	port->iobase = 1; /* mark port in use */
	512	port->mapbase = base;
	513	port->membase = NULL;
	514	port->ops = &ulite_ops;
	515	port->irq = irq;
	516	port->flags = UPF_BOOT_AUTOCONF;
	517	port->dev = dev;
	518	port->type = PORT_UNKNOWN;
	519	port->line = id;
	520
	521	dev_set_drvdata(dev, port);
	522
	523	/* Register the port */
	524	rc = uart_add_one_port(&ulite_uart_driver, port);
	525	if (rc) {
	526	dev_err(dev, "uart_add_one_port() failed; err=%i\n", rc);
	527	port->mapbase = 0;
	528	dev_set_drvdata(dev, NULL);
	529	return rc;
	530	}
238b8721	531
8fa7b610 GL	532	return 0;
8fa7b610 GL	533	}
238b8721	534
435706b3 GL	535	/** ulite_release: register a uartlite device with the driver
	536	*
	537	* @dev: pointer to device structure
	538	*/
8fa7b610 GL	539	static int __devinit ulite_release(struct device *dev)
	540	{
	541	struct uart_port *port = dev_get_drvdata(dev);
	542	int rc = 0;
238b8721	543
8fa7b610 GL	544	if (port) {
	545	rc = uart_remove_one_port(&ulite_uart_driver, port);
	546	dev_set_drvdata(dev, NULL);
	547	port->mapbase = 0;
	548	}
238b8721	549
8fa7b610	550	return rc;
238b8721 PK	551	}
238b8721 PK	552
435706b3 GL	553	/* ---------------------------------------------------------------------
	554	* Platform bus binding
	555	*/
	556
8fa7b610	557	static int __devinit ulite_probe(struct platform_device *pdev)
238b8721	558	{
8fa7b610	559	struct resource res, res2;
238b8721	560
8fa7b610 GL	561	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
	562	if (!res)
	563	return -ENODEV;
238b8721	564
8fa7b610 GL	565	res2 = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
	566	if (!res2)
	567	return -ENODEV;
238b8721	568
8fa7b610 GL	569	return ulite_assign(&pdev->dev, pdev->id, res->start, res2->start);
8fa7b610 GL	570	}
238b8721	571
8fa7b610 GL	572	static int ulite_remove(struct platform_device *pdev)
	573	{
	574	return ulite_release(&pdev->dev);
238b8721 PK	575	}
	576
	577	static struct platform_driver ulite_platform_driver = {
	578	.probe = ulite_probe,
	579	.remove = ulite_remove,
	580	.driver = {
	581	.owner = THIS_MODULE,
	582	.name = "uartlite",
	583	},
	584	};
	585
852e1ea7 GL	586	/* ---------------------------------------------------------------------
	587	* OF bus bindings
	588	*/
	589	#if defined(CONFIG_OF)
	590	static int __devinit
	591	ulite_of_probe(struct of_device op, const struct of_device_id match)
	592	{
	593	struct resource res;
	594	const unsigned int *id;
	595	int irq, rc;
	596
	597	dev_dbg(&op->dev, "%s(%p, %p)\n", __FUNCTION__, op, match);
	598
	599	rc = of_address_to_resource(op->node, 0, &res);
	600	if (rc) {
	601	dev_err(&op->dev, "invalide address\n");
	602	return rc;
	603	}
	604
	605	irq = irq_of_parse_and_map(op->node, 0);
	606
	607	id = of_get_property(op->node, "port-number", NULL);
	608
	609	return ulite_assign(&op->dev, id ? *id : -1, res.start, irq);
	610	}
	611
	612	static int __devexit ulite_of_remove(struct of_device *op)
	613	{
	614	return ulite_release(&op->dev);
	615	}
	616
	617	/* Match table for of_platform binding */
	618	static struct of_device_id __devinit ulite_of_match[] = {
	619	{ .type = "serial", .compatible = "xilinx,uartlite", },
	620	{},
	621	};
	622	MODULE_DEVICE_TABLE(of, ulite_of_match);
	623
	624	static struct of_platform_driver ulite_of_driver = {
	625	.owner = THIS_MODULE,
	626	.name = "uartlite",
	627	.match_table = ulite_of_match,
	628	.probe = ulite_of_probe,
	629	.remove = __devexit_p(ulite_of_remove),
	630	.driver = {
	631	.name = "uartlite",
	632	},
	633	};
	634
	635	/* Registration helpers to keep the number of #ifdefs to a minimum */
	636	static inline int __init ulite_of_register(void)
	637	{
	638	pr_debug("uartlite: calling of_register_platform_driver()\n");
	639	return of_register_platform_driver(&ulite_of_driver);
	640	}
	641
	642	static inline void __exit ulite_of_unregister(void)
	643	{
	644	of_unregister_platform_driver(&ulite_of_driver);
	645	}
	646	#else /* CONFIG_OF */
	647	/* CONFIG_OF not enabled; do nothing helpers */
	648	static inline int __init ulite_of_register(void) { return 0; }
	649	static inline void __exit ulite_of_unregister(void) { }
650	#endif /* CONFIG_OF */
651
435706b3 GL	652	/* ---------------------------------------------------------------------
	653	* Module setup/teardown
	654	*/
	655
238b8721 PK	656	int __init ulite_init(void)
	657	{
	658	int ret;
	659
852e1ea7	660	pr_debug("uartlite: calling uart_register_driver()\n");
238b8721 PK	661	ret = uart_register_driver(&ulite_uart_driver);
238b8721 PK	662	if (ret)
852e1ea7 GL	663	goto err_uart;
	664
	665	ret = ulite_of_register();
	666	if (ret)
	667	goto err_of;
238b8721	668
852e1ea7	669	pr_debug("uartlite: calling platform_driver_register()\n");
238b8721 PK	670	ret = platform_driver_register(&ulite_platform_driver);
238b8721 PK	671	if (ret)
852e1ea7 GL	672	goto err_plat;
	673
	674	return 0;
238b8721	675
852e1ea7 GL	676	err_plat:
	677	ulite_of_unregister();
	678	err_of:
	679	uart_unregister_driver(&ulite_uart_driver);
	680	err_uart:
	681	printk(KERN_ERR "registering uartlite driver failed: err=%i", ret);
238b8721 PK	682	return ret;
	683	}
	684
	685	void __exit ulite_exit(void)
	686	{
	687	platform_driver_unregister(&ulite_platform_driver);
852e1ea7	688	ulite_of_unregister();
238b8721 PK	689	uart_unregister_driver(&ulite_uart_driver);
	690	}
	691
	692	module_init(ulite_init);
	693	module_exit(ulite_exit);
	694
	695	MODULE_AUTHOR("Peter Korsgaard <jacmet@sunsite.dk>");
	696	MODULE_DESCRIPTION("Xilinx uartlite serial driver");
	697	MODULE_LICENSE("GPL");