[linux-2.6-block.git] / drivers / tty / serial / apbuart.c

/*
 *  Driver for GRLIB serial ports (APBUART)
 *
 *  Based on linux/drivers/serial/amba.c
 *
 *  Copyright (C) 2000 Deep Blue Solutions Ltd.
 *  Copyright (C) 2003 Konrad Eisele <eiselekd@web.de>
 *  Copyright (C) 2006 Daniel Hellstrom <daniel@gaisler.com>, Aeroflex Gaisler AB
 *  Copyright (C) 2008 Gilead Kutnick <kutnickg@zin-tech.com>
 *  Copyright (C) 2009 Kristoffer Glembo <kristoffer@gaisler.com>, Aeroflex Gaisler AB
 */

#if defined(CONFIG_SERIAL_GRLIB_GAISLER_APBUART_CONSOLE) && defined(CONFIG_MAGIC_SYSRQ)
#define SUPPORT_SYSRQ
#endif

#include <linux/module.h>
#include <linux/tty.h>
#include <linux/tty_flip.h>
#include <linux/ioport.h>
#include <linux/init.h>
#include <linux/serial.h>
#include <linux/console.h>
#include <linux/sysrq.h>
#include <linux/kthread.h>
#include <linux/device.h>
#include <linux/of.h>
#include <linux/of_device.h>
#include <linux/of_platform.h>
#include <linux/of_irq.h>
#include <linux/platform_device.h>
#include <linux/io.h>
#include <linux/serial_core.h>
#include <asm/irq.h>

#include "apbuart.h"

#define SERIAL_APBUART_MAJOR	TTY_MAJOR
#define SERIAL_APBUART_MINOR	64
#define UART_DUMMY_RSR_RX	0x8000	/* for ignore all read */

static void apbuart_tx_chars(struct uart_port *port);

static void apbuart_stop_tx(struct uart_port *port)
{
	unsigned int cr;

	cr = UART_GET_CTRL(port);
	cr &= ~UART_CTRL_TI;
	UART_PUT_CTRL(port, cr);
}

static void apbuart_start_tx(struct uart_port *port)
{
	unsigned int cr;

	cr = UART_GET_CTRL(port);
	cr |= UART_CTRL_TI;
	UART_PUT_CTRL(port, cr);

	if (UART_GET_STATUS(port) & UART_STATUS_THE)
		apbuart_tx_chars(port);
}

static void apbuart_stop_rx(struct uart_port *port)
{
	unsigned int cr;

	cr = UART_GET_CTRL(port);
	cr &= ~(UART_CTRL_RI);
	UART_PUT_CTRL(port, cr);
}

static void apbuart_enable_ms(struct uart_port *port)
{
	/* No modem status change interrupts for APBUART */
}

static void apbuart_rx_chars(struct uart_port *port)
{
	struct tty_struct *tty = port->state->port.tty;
	unsigned int status, ch, rsr, flag;
	unsigned int max_chars = port->fifosize;

	status = UART_GET_STATUS(port);

	while (UART_RX_DATA(status) && (max_chars--)) {

		ch = UART_GET_CHAR(port);
		flag = TTY_NORMAL;

		port->icount.rx++;

		rsr = UART_GET_STATUS(port) | UART_DUMMY_RSR_RX;
		UART_PUT_STATUS(port, 0);
		if (rsr & UART_STATUS_ERR) {

			if (rsr & UART_STATUS_BR) {
				rsr &= ~(UART_STATUS_FE | UART_STATUS_PE);
				port->icount.brk++;
				if (uart_handle_break(port))
					goto ignore_char;
			} else if (rsr & UART_STATUS_PE) {
				port->icount.parity++;
			} else if (rsr & UART_STATUS_FE) {
				port->icount.frame++;
			}
			if (rsr & UART_STATUS_OE)
				port->icount.overrun++;

			rsr &= port->read_status_mask;

			if (rsr & UART_STATUS_PE)
				flag = TTY_PARITY;
			else if (rsr & UART_STATUS_FE)
				flag = TTY_FRAME;
		}

		if (uart_handle_sysrq_char(port, ch))
			goto ignore_char;

		uart_insert_char(port, rsr, UART_STATUS_OE, ch, flag);


	      ignore_char:
		status = UART_GET_STATUS(port);
	}

	tty_flip_buffer_push(tty);
}

static void apbuart_tx_chars(struct uart_port *port)
{
	struct circ_buf *xmit = &port->state->xmit;
	int count;

	if (port->x_char) {
		UART_PUT_CHAR(port, port->x_char);
		port->icount.tx++;
		port->x_char = 0;
		return;
	}

	if (uart_circ_empty(xmit) || uart_tx_stopped(port)) {
		apbuart_stop_tx(port);
		return;
	}

	/* amba: fill FIFO */
	count = port->fifosize >> 1;
	do {
		UART_PUT_CHAR(port, xmit->buf[xmit->tail]);
		xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
		port->icount.tx++;
		if (uart_circ_empty(xmit))
			break;
	} while (--count > 0);

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

	if (uart_circ_empty(xmit))
		apbuart_stop_tx(port);
}

static irqreturn_t apbuart_int(int irq, void *dev_id)
{
	struct uart_port *port = dev_id;
	unsigned int status;

	spin_lock(&port->lock);

	status = UART_GET_STATUS(port);
	if (status & UART_STATUS_DR)
		apbuart_rx_chars(port);
	if (status & UART_STATUS_THE)
		apbuart_tx_chars(port);

	spin_unlock(&port->lock);

	return IRQ_HANDLED;
}

static unsigned int apbuart_tx_empty(struct uart_port *port)
{
	unsigned int status = UART_GET_STATUS(port);
	return status & UART_STATUS_THE ? TIOCSER_TEMT : 0;
}

static unsigned int apbuart_get_mctrl(struct uart_port *port)
{
	/* The GRLIB APBUART handles flow control in hardware */
	return TIOCM_CAR | TIOCM_DSR | TIOCM_CTS;
}

static void apbuart_set_mctrl(struct uart_port *port, unsigned int mctrl)
{
	/* The GRLIB APBUART handles flow control in hardware */
}

static void apbuart_break_ctl(struct uart_port *port, int break_state)
{
	/* We don't support sending break */
}

static int apbuart_startup(struct uart_port *port)
{
	int retval;
	unsigned int cr;

	/* Allocate the IRQ */
	retval = request_irq(port->irq, apbuart_int, 0, "apbuart", port);
	if (retval)
		return retval;

	/* Finally, enable interrupts */
	cr = UART_GET_CTRL(port);
	UART_PUT_CTRL(port,
		      cr | UART_CTRL_RE | UART_CTRL_TE |
		      UART_CTRL_RI | UART_CTRL_TI);

	return 0;
}

static void apbuart_shutdown(struct uart_port *port)
{
	unsigned int cr;

	/* disable all interrupts, disable the port */
	cr = UART_GET_CTRL(port);
	UART_PUT_CTRL(port,
		      cr & ~(UART_CTRL_RE | UART_CTRL_TE |
			     UART_CTRL_RI | UART_CTRL_TI));

	/* Free the interrupt */
	free_irq(port->irq, port);
}

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

	/* Ask the core to calculate the divisor for us. */
	baud = uart_get_baud_rate(port, termios, old, 0, port->uartclk / 16);
	if (baud == 0)
		panic("invalid baudrate %i\n", port->uartclk / 16);

	/* uart_get_divisor calc a *16 uart freq, apbuart is *8 */
	quot = (uart_get_divisor(port, baud)) * 2;
	cr = UART_GET_CTRL(port);
	cr &= ~(UART_CTRL_PE | UART_CTRL_PS);

	if (termios->c_cflag & PARENB) {
		cr |= UART_CTRL_PE;
		if ((termios->c_cflag & PARODD))
			cr |= UART_CTRL_PS;
	}

	/* Enable flow control. */
	if (termios->c_cflag & CRTSCTS)
		cr |= UART_CTRL_FL;

	spin_lock_irqsave(&port->lock, flags);

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

	port->read_status_mask = UART_STATUS_OE;
	if (termios->c_iflag & INPCK)
		port->read_status_mask |= UART_STATUS_FE | UART_STATUS_PE;

	/* Characters to ignore */
	port->ignore_status_mask = 0;
	if (termios->c_iflag & IGNPAR)
		port->ignore_status_mask |= UART_STATUS_FE | UART_STATUS_PE;

	/* Ignore all characters if CREAD is not set. */
	if ((termios->c_cflag & CREAD) == 0)
		port->ignore_status_mask |= UART_DUMMY_RSR_RX;

	/* Set baud rate */
	quot -= 1;
	UART_PUT_SCAL(port, quot);
	UART_PUT_CTRL(port, cr);

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

static const char *apbuart_type(struct uart_port *port)
{
	return port->type == PORT_APBUART ? "GRLIB/APBUART" : NULL;
}

static void apbuart_release_port(struct uart_port *port)
{
	release_mem_region(port->mapbase, 0x100);
}

static int apbuart_request_port(struct uart_port *port)
{
	return request_mem_region(port->mapbase, 0x100, "grlib-apbuart")
	    != NULL ? 0 : -EBUSY;
	return 0;
}

/* Configure/autoconfigure the port */
static void apbuart_config_port(struct uart_port *port, int flags)
{
	if (flags & UART_CONFIG_TYPE) {
		port->type = PORT_APBUART;
		apbuart_request_port(port);
	}
}

/* Verify the new serial_struct (for TIOCSSERIAL) */
static int apbuart_verify_port(struct uart_port *port,
			       struct serial_struct *ser)
{
	int ret = 0;
	if (ser->type != PORT_UNKNOWN && ser->type != PORT_APBUART)
		ret = -EINVAL;
	if (ser->irq < 0 || ser->irq >= NR_IRQS)
		ret = -EINVAL;
	if (ser->baud_base < 9600)
		ret = -EINVAL;
	return ret;
}

static struct uart_ops grlib_apbuart_ops = {
	.tx_empty = apbuart_tx_empty,
	.set_mctrl = apbuart_set_mctrl,
	.get_mctrl = apbuart_get_mctrl,
	.stop_tx = apbuart_stop_tx,
	.start_tx = apbuart_start_tx,
	.stop_rx = apbuart_stop_rx,
	.enable_ms = apbuart_enable_ms,
	.break_ctl = apbuart_break_ctl,
	.startup = apbuart_startup,
	.shutdown = apbuart_shutdown,
	.set_termios = apbuart_set_termios,
	.type = apbuart_type,
	.release_port = apbuart_release_port,
	.request_port = apbuart_request_port,
	.config_port = apbuart_config_port,
	.verify_port = apbuart_verify_port,
};

static struct uart_port grlib_apbuart_ports[UART_NR];
static struct device_node *grlib_apbuart_nodes[UART_NR];

static int apbuart_scan_fifo_size(struct uart_port *port, int portnumber)
{
	int ctrl, loop = 0;
	int status;
	int fifosize;
	unsigned long flags;

	ctrl = UART_GET_CTRL(port);

	/*
	 * Enable the transceiver and wait for it to be ready to send data.
	 * Clear interrupts so that this process will not be externally
	 * interrupted in the middle (which can cause the transceiver to
	 * drain prematurely).
	 */

	local_irq_save(flags);

	UART_PUT_CTRL(port, ctrl | UART_CTRL_TE);

	while (!UART_TX_READY(UART_GET_STATUS(port)))
		loop++;

	/*
	 * Disable the transceiver so data isn't actually sent during the
	 * actual test.
	 */

	UART_PUT_CTRL(port, ctrl & ~(UART_CTRL_TE));

	fifosize = 1;
	UART_PUT_CHAR(port, 0);

	/*
	 * So long as transmitting a character increments the tranceivier FIFO
	 * length the FIFO must be at least that big. These bytes will
	 * automatically drain off of the FIFO.
	 */

	status = UART_GET_STATUS(port);
	while (((status >> 20) & 0x3F) == fifosize) {
		fifosize++;
		UART_PUT_CHAR(port, 0);
		status = UART_GET_STATUS(port);
	}

	fifosize--;

	UART_PUT_CTRL(port, ctrl);
	local_irq_restore(flags);

	if (fifosize == 0)
		fifosize = 1;

	return fifosize;
}

static void apbuart_flush_fifo(struct uart_port *port)
{
	int i;

	for (i = 0; i < port->fifosize; i++)
		UART_GET_CHAR(port);
}


/* ======================================================================== */
/* Console driver, if enabled                                               */
/* ======================================================================== */

#ifdef CONFIG_SERIAL_GRLIB_GAISLER_APBUART_CONSOLE

static void apbuart_console_putchar(struct uart_port *port, int ch)
{
	unsigned int status;
	do {
		status = UART_GET_STATUS(port);
	} while (!UART_TX_READY(status));
	UART_PUT_CHAR(port, ch);
}

static void
apbuart_console_write(struct console *co, const char *s, unsigned int count)
{
	struct uart_port *port = &grlib_apbuart_ports[co->index];
	unsigned int status, old_cr, new_cr;

	/* First save the CR then disable the interrupts */
	old_cr = UART_GET_CTRL(port);
	new_cr = old_cr & ~(UART_CTRL_RI | UART_CTRL_TI);
	UART_PUT_CTRL(port, new_cr);

	uart_console_write(port, s, count, apbuart_console_putchar);

	/*
	 *      Finally, wait for transmitter to become empty
	 *      and restore the TCR
	 */
	do {
		status = UART_GET_STATUS(port);
	} while (!UART_TX_READY(status));
	UART_PUT_CTRL(port, old_cr);
}

static void __init
apbuart_console_get_options(struct uart_port *port, int *baud,
			    int *parity, int *bits)
{
	if (UART_GET_CTRL(port) & (UART_CTRL_RE | UART_CTRL_TE)) {

		unsigned int quot, status;
		status = UART_GET_STATUS(port);

		*parity = 'n';
		if (status & UART_CTRL_PE) {
			if ((status & UART_CTRL_PS) == 0)
				*parity = 'e';
			else
				*parity = 'o';
		}

		*bits = 8;
		quot = UART_GET_SCAL(port) / 8;
		*baud = port->uartclk / (16 * (quot + 1));
	}
}

static int __init apbuart_console_setup(struct console *co, char *options)
{
	struct uart_port *port;
	int baud = 38400;
	int bits = 8;
	int parity = 'n';
	int flow = 'n';

	pr_debug("apbuart_console_setup co=%p, co->index=%i, options=%s\n",
		 co, co->index, options);

	/*
	 * Check whether an invalid uart number has been specified, and
	 * if so, search for the first available port that does have
	 * console support.
	 */
	if (co->index >= grlib_apbuart_port_nr)
		co->index = 0;

	port = &grlib_apbuart_ports[co->index];

	spin_lock_init(&port->lock);

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

	return uart_set_options(port, co, baud, parity, bits, flow);
}

static struct uart_driver grlib_apbuart_driver;

static struct console grlib_apbuart_console = {
	.name = "ttyS",
	.write = apbuart_console_write,
	.device = uart_console_device,
	.setup = apbuart_console_setup,
	.flags = CON_PRINTBUFFER,
	.index = -1,
	.data = &grlib_apbuart_driver,
};


static int grlib_apbuart_configure(void);

static int __init apbuart_console_init(void)
{
	if (grlib_apbuart_configure())
		return -ENODEV;
	register_console(&grlib_apbuart_console);
	return 0;
}

console_initcall(apbuart_console_init);

#define APBUART_CONSOLE	(&grlib_apbuart_console)
#else
#define APBUART_CONSOLE	NULL
#endif

static struct uart_driver grlib_apbuart_driver = {
	.owner = THIS_MODULE,
	.driver_name = "serial",
	.dev_name = "ttyS",
	.major = SERIAL_APBUART_MAJOR,
	.minor = SERIAL_APBUART_MINOR,
	.nr = UART_NR,
	.cons = APBUART_CONSOLE,
};


/* ======================================================================== */
/* OF Platform Driver                                                       */
/* ======================================================================== */

static int apbuart_probe(struct platform_device *op)
{
	int i;
	struct uart_port *port = NULL;

	for (i = 0; i < grlib_apbuart_port_nr; i++) {
		if (op->dev.of_node == grlib_apbuart_nodes[i])
			break;
	}

	port = &grlib_apbuart_ports[i];
	port->dev = &op->dev;
	port->irq = op->archdata.irqs[0];

	uart_add_one_port(&grlib_apbuart_driver, (struct uart_port *) port);

	apbuart_flush_fifo((struct uart_port *) port);

	printk(KERN_INFO "grlib-apbuart at 0x%llx, irq %d\n",
	       (unsigned long long) port->mapbase, port->irq);
	return 0;
}

static struct of_device_id apbuart_match[] = {
	{
	 .name = "GAISLER_APBUART",
	 },
	{
	 .name = "01_00c",
	 },
	{},
};

static struct platform_driver grlib_apbuart_of_driver = {
	.probe = apbuart_probe,
	.driver = {
		.owner = THIS_MODULE,
		.name = "grlib-apbuart",
		.of_match_table = apbuart_match,
	},
};


static int __init grlib_apbuart_configure(void)
{
	struct device_node *np;
	int line = 0;

	for_each_matching_node(np, apbuart_match) {
		const int *ampopts;
		const u32 *freq_hz;
		const struct amba_prom_registers *regs;
		struct uart_port *port;
		unsigned long addr;

		ampopts = of_get_property(np, "ampopts", NULL);
		if (ampopts && (*ampopts == 0))
			continue; /* Ignore if used by another OS instance */
		regs = of_get_property(np, "reg", NULL);
		/* Frequency of APB Bus is frequency of UART */
		freq_hz = of_get_property(np, "freq", NULL);

		if (!regs || !freq_hz || (*freq_hz == 0))
			continue;

		grlib_apbuart_nodes[line] = np;

		addr = regs->phys_addr;

		port = &grlib_apbuart_ports[line];

		port->mapbase = addr;
		port->membase = ioremap(addr, sizeof(struct grlib_apbuart_regs_map));
		port->irq = 0;
		port->iotype = UPIO_MEM;
		port->ops = &grlib_apbuart_ops;
		port->flags = UPF_BOOT_AUTOCONF;
		port->line = line;
		port->uartclk = *freq_hz;
		port->fifosize = apbuart_scan_fifo_size((struct uart_port *) port, line);
		line++;

		/* We support maximum UART_NR uarts ... */
		if (line == UART_NR)
			break;
	}

	grlib_apbuart_driver.nr = grlib_apbuart_port_nr = line;
	return line ? 0 : -ENODEV;
}

static int __init grlib_apbuart_init(void)
{
	int ret;

	/* Find all APBUARTS in device the tree and initialize their ports */
	ret = grlib_apbuart_configure();
	if (ret)
		return ret;

	printk(KERN_INFO "Serial: GRLIB APBUART driver\n");

	ret = uart_register_driver(&grlib_apbuart_driver);

	if (ret) {
		printk(KERN_ERR "%s: uart_register_driver failed (%i)\n",
		       __FILE__, ret);
		return ret;
	}

	ret = platform_driver_register(&grlib_apbuart_of_driver);
	if (ret) {
		printk(KERN_ERR
		       "%s: platform_driver_register failed (%i)\n",
		       __FILE__, ret);
		uart_unregister_driver(&grlib_apbuart_driver);
		return ret;
	}

	return ret;
}

static void __exit grlib_apbuart_exit(void)
{
	int i;

	for (i = 0; i < grlib_apbuart_port_nr; i++)
		uart_remove_one_port(&grlib_apbuart_driver,
				     &grlib_apbuart_ports[i]);

	uart_unregister_driver(&grlib_apbuart_driver);
	platform_driver_unregister(&grlib_apbuart_of_driver);
}

module_init(grlib_apbuart_init);
module_exit(grlib_apbuart_exit);

MODULE_AUTHOR("Aeroflex Gaisler AB");
MODULE_DESCRIPTION("GRLIB APBUART serial driver");
MODULE_VERSION("2.1");
MODULE_LICENSE("GPL");
Commit	Line	Data
d4ac42a5 KG	1	/*
	2	* Driver for GRLIB serial ports (APBUART)
	3	*
	4	* Based on linux/drivers/serial/amba.c
	5	*
	6	* Copyright (C) 2000 Deep Blue Solutions Ltd.
	7	* Copyright (C) 2003 Konrad Eisele <eiselekd@web.de>
	8	* Copyright (C) 2006 Daniel Hellstrom <daniel@gaisler.com>, Aeroflex Gaisler AB
	9	* Copyright (C) 2008 Gilead Kutnick <kutnickg@zin-tech.com>
	10	* Copyright (C) 2009 Kristoffer Glembo <kristoffer@gaisler.com>, Aeroflex Gaisler AB
	11	*/
	12
	13	#if defined(CONFIG_SERIAL_GRLIB_GAISLER_APBUART_CONSOLE) && defined(CONFIG_MAGIC_SYSRQ)
	14	#define SUPPORT_SYSRQ
	15	#endif
	16
	17	#include <linux/module.h>
	18	#include <linux/tty.h>
ee160a38	19	#include <linux/tty_flip.h>
d4ac42a5 KG	20	#include <linux/ioport.h>
	21	#include <linux/init.h>
	22	#include <linux/serial.h>
	23	#include <linux/console.h>
	24	#include <linux/sysrq.h>
	25	#include <linux/kthread.h>
	26	#include <linux/device.h>
	27	#include <linux/of.h>
	28	#include <linux/of_device.h>
ddaf1b27	29	#include <linux/of_platform.h>
f28f3313	30	#include <linux/of_irq.h>
d4ac42a5 KG	31	#include <linux/platform_device.h>
	32	#include <linux/io.h>
	33	#include <linux/serial_core.h>
	34	#include <asm/irq.h>
d4ac42a5 KG	35
	36	#include "apbuart.h"
	37
	38	#define SERIAL_APBUART_MAJOR TTY_MAJOR
	39	#define SERIAL_APBUART_MINOR 64
	40	#define UART_DUMMY_RSR_RX 0x8000 /* for ignore all read */
	41
	42	static void apbuart_tx_chars(struct uart_port *port);
	43
	44	static void apbuart_stop_tx(struct uart_port *port)
	45	{
	46	unsigned int cr;
	47
	48	cr = UART_GET_CTRL(port);
	49	cr &= ~UART_CTRL_TI;
	50	UART_PUT_CTRL(port, cr);
	51	}
	52
	53	static void apbuart_start_tx(struct uart_port *port)
	54	{
	55	unsigned int cr;
	56
	57	cr = UART_GET_CTRL(port);
	58	cr \|= UART_CTRL_TI;
	59	UART_PUT_CTRL(port, cr);
	60
	61	if (UART_GET_STATUS(port) & UART_STATUS_THE)
	62	apbuart_tx_chars(port);
	63	}
	64
	65	static void apbuart_stop_rx(struct uart_port *port)
	66	{
	67	unsigned int cr;
	68
	69	cr = UART_GET_CTRL(port);
	70	cr &= ~(UART_CTRL_RI);
	71	UART_PUT_CTRL(port, cr);
	72	}
	73
	74	static void apbuart_enable_ms(struct uart_port *port)
	75	{
	76	/* No modem status change interrupts for APBUART */
	77	}
	78
	79	static void apbuart_rx_chars(struct uart_port *port)
	80	{
	81	struct tty_struct *tty = port->state->port.tty;
	82	unsigned int status, ch, rsr, flag;
	83	unsigned int max_chars = port->fifosize;
	84
	85	status = UART_GET_STATUS(port);
	86
	87	while (UART_RX_DATA(status) && (max_chars--)) {
	88
	89	ch = UART_GET_CHAR(port);
	90	flag = TTY_NORMAL;
	91
	92	port->icount.rx++;
	93
	94	rsr = UART_GET_STATUS(port) \| UART_DUMMY_RSR_RX;
	95	UART_PUT_STATUS(port, 0);
	96	if (rsr & UART_STATUS_ERR) {
	97
	98	if (rsr & UART_STATUS_BR) {
99	rsr &= ~(UART_STATUS_FE \| UART_STATUS_PE);
100	port->icount.brk++;
101	if (uart_handle_break(port))
102	goto ignore_char;
103	} else if (rsr & UART_STATUS_PE) {
104	port->icount.parity++;
105	} else if (rsr & UART_STATUS_FE) {
106	port->icount.frame++;
107	}
108	if (rsr & UART_STATUS_OE)
109	port->icount.overrun++;
110
111	rsr &= port->read_status_mask;
112
113	if (rsr & UART_STATUS_PE)
114	flag = TTY_PARITY;
115	else if (rsr & UART_STATUS_FE)
116	flag = TTY_FRAME;
117	}
118
119	if (uart_handle_sysrq_char(port, ch))
120	goto ignore_char;
121
122	uart_insert_char(port, rsr, UART_STATUS_OE, ch, flag);
123
124
125	ignore_char:
126	status = UART_GET_STATUS(port);
127	}
128
129	tty_flip_buffer_push(tty);
130	}
131
132	static void apbuart_tx_chars(struct uart_port *port)
133	{
134	struct circ_buf *xmit = &port->state->xmit;
135	int count;
136
137	if (port->x_char) {
138	UART_PUT_CHAR(port, port->x_char);
139	port->icount.tx++;
140	port->x_char = 0;
141	return;
142	}
143
144	if (uart_circ_empty(xmit) \|\| uart_tx_stopped(port)) {
145	apbuart_stop_tx(port);
146	return;
147	}
148
149	/* amba: fill FIFO */
150	count = port->fifosize >> 1;
151	do {
152	UART_PUT_CHAR(port, xmit->buf[xmit->tail]);
153	xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
154	port->icount.tx++;
155	if (uart_circ_empty(xmit))
156	break;
157	} while (--count > 0);
158
159	if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
160	uart_write_wakeup(port);
161
162	if (uart_circ_empty(xmit))
163	apbuart_stop_tx(port);
164	}
165
166	static irqreturn_t apbuart_int(int irq, void *dev_id)
167	{
168	struct uart_port *port = dev_id;
169	unsigned int status;
170
171	spin_lock(&port->lock);
172
173	status = UART_GET_STATUS(port);
174	if (status & UART_STATUS_DR)
175	apbuart_rx_chars(port);
176	if (status & UART_STATUS_THE)
177	apbuart_tx_chars(port);
178
179	spin_unlock(&port->lock);
180
181	return IRQ_HANDLED;
182	}
183
184	static unsigned int apbuart_tx_empty(struct uart_port *port)
185	{
186	unsigned int status = UART_GET_STATUS(port);
187	return status & UART_STATUS_THE ? TIOCSER_TEMT : 0;
188	}
189
190	static unsigned int apbuart_get_mctrl(struct uart_port *port)
191	{
192	/* The GRLIB APBUART handles flow control in hardware */
193	return TIOCM_CAR \| TIOCM_DSR \| TIOCM_CTS;
194	}
195
196	static void apbuart_set_mctrl(struct uart_port *port, unsigned int mctrl)
197	{
198	/* The GRLIB APBUART handles flow control in hardware */
199	}
200
201	static void apbuart_break_ctl(struct uart_port *port, int break_state)
202	{
203	/* We don't support sending break */
204	}
205
206	static int apbuart_startup(struct uart_port *port)
207	{
208	int retval;
209	unsigned int cr;
210
211	/* Allocate the IRQ */
212	retval = request_irq(port->irq, apbuart_int, 0, "apbuart", port);
213	if (retval)
214	return retval;
215
216	/* Finally, enable interrupts */
217	cr = UART_GET_CTRL(port);
218	UART_PUT_CTRL(port,
219	cr \| UART_CTRL_RE \| UART_CTRL_TE \|
220	UART_CTRL_RI \| UART_CTRL_TI);
221
222	return 0;
223	}
224
225	static void apbuart_shutdown(struct uart_port *port)
226	{
227	unsigned int cr;
228
229	/* disable all interrupts, disable the port */
230	cr = UART_GET_CTRL(port);
231	UART_PUT_CTRL(port,
232	cr & ~(UART_CTRL_RE \| UART_CTRL_TE \|
233	UART_CTRL_RI \| UART_CTRL_TI));
234
235	/* Free the interrupt */
236	free_irq(port->irq, port);
237	}
238
239	static void apbuart_set_termios(struct uart_port *port,
240	struct ktermios termios, struct ktermios old)
241	{
242	unsigned int cr;
243	unsigned long flags;
244	unsigned int baud, quot;
245
246	/* Ask the core to calculate the divisor for us. */
247	baud = uart_get_baud_rate(port, termios, old, 0, port->uartclk / 16);
248	if (baud == 0)
249	panic("invalid baudrate %i\n", port->uartclk / 16);
250
251	/* uart_get_divisor calc a 16 uart freq, apbuart is 8 */
252	quot = (uart_get_divisor(port, baud)) * 2;
253	cr = UART_GET_CTRL(port);
254	cr &= ~(UART_CTRL_PE \| UART_CTRL_PS);
255
256	if (termios->c_cflag & PARENB) {
257	cr \|= UART_CTRL_PE;
258	if ((termios->c_cflag & PARODD))
259	cr \|= UART_CTRL_PS;
260	}
261
262	/* Enable flow control. */
263	if (termios->c_cflag & CRTSCTS)
264	cr \|= UART_CTRL_FL;
265
266	spin_lock_irqsave(&port->lock, flags);
267
268	/* Update the per-port timeout. */
269	uart_update_timeout(port, termios->c_cflag, baud);
270
271	port->read_status_mask = UART_STATUS_OE;
272	if (termios->c_iflag & INPCK)
273	port->read_status_mask \|= UART_STATUS_FE \| UART_STATUS_PE;
274
275	/* Characters to ignore */
276	port->ignore_status_mask = 0;
277	if (termios->c_iflag & IGNPAR)
278	port->ignore_status_mask \|= UART_STATUS_FE \| UART_STATUS_PE;
279
280	/* Ignore all characters if CREAD is not set. */
281	if ((termios->c_cflag & CREAD) == 0)
282	port->ignore_status_mask \|= UART_DUMMY_RSR_RX;
283
284	/* Set baud rate */
285	quot -= 1;
286	UART_PUT_SCAL(port, quot);
287	UART_PUT_CTRL(port, cr);
288
289	spin_unlock_irqrestore(&port->lock, flags);
290	}
291
292	static const char apbuart_type(struct uart_port port)
293	{
294	return port->type == PORT_APBUART ? "GRLIB/APBUART" : NULL;
295	}
296
297	static void apbuart_release_port(struct uart_port *port)
298	{
299	release_mem_region(port->mapbase, 0x100);
300	}
301
302	static int apbuart_request_port(struct uart_port *port)
303	{
304	return request_mem_region(port->mapbase, 0x100, "grlib-apbuart")
305	!= NULL ? 0 : -EBUSY;
306	return 0;
307	}
308
309	/* Configure/autoconfigure the port */
310	static void apbuart_config_port(struct uart_port *port, int flags)
311	{
312	if (flags & UART_CONFIG_TYPE) {
313	port->type = PORT_APBUART;
314	apbuart_request_port(port);
315	}
316	}
317
318	/* Verify the new serial_struct (for TIOCSSERIAL) */
319	static int apbuart_verify_port(struct uart_port *port,
320	struct serial_struct *ser)
321	{
322	int ret = 0;
323	if (ser->type != PORT_UNKNOWN && ser->type != PORT_APBUART)
324	ret = -EINVAL;
325	if (ser->irq < 0 \|\| ser->irq >= NR_IRQS)
326	ret = -EINVAL;
327	if (ser->baud_base < 9600)
328	ret = -EINVAL;
329	return ret;
330	}
331
332	static struct uart_ops grlib_apbuart_ops = {
333	.tx_empty = apbuart_tx_empty,
334	.set_mctrl = apbuart_set_mctrl,
335	.get_mctrl = apbuart_get_mctrl,
336	.stop_tx = apbuart_stop_tx,
337	.start_tx = apbuart_start_tx,
338	.stop_rx = apbuart_stop_rx,
339	.enable_ms = apbuart_enable_ms,
340	.break_ctl = apbuart_break_ctl,
341	.startup = apbuart_startup,
342	.shutdown = apbuart_shutdown,
343	.set_termios = apbuart_set_termios,
344	.type = apbuart_type,
345	.release_port = apbuart_release_port,
346	.request_port = apbuart_request_port,
347	.config_port = apbuart_config_port,
348	.verify_port = apbuart_verify_port,
349	};
350
351	static struct uart_port grlib_apbuart_ports[UART_NR];
352	static struct device_node *grlib_apbuart_nodes[UART_NR];
353
354	static int apbuart_scan_fifo_size(struct uart_port *port, int portnumber)
355	{
356	int ctrl, loop = 0;
357	int status;
358	int fifosize;
359	unsigned long flags;
360
361	ctrl = UART_GET_CTRL(port);
362
363	/*
364	* Enable the transceiver and wait for it to be ready to send data.
365	* Clear interrupts so that this process will not be externally
366	* interrupted in the middle (which can cause the transceiver to
367	* drain prematurely).
368	*/
369
370	local_irq_save(flags);
371
372	UART_PUT_CTRL(port, ctrl \| UART_CTRL_TE);
373
374	while (!UART_TX_READY(UART_GET_STATUS(port)))
375	loop++;
376
377	/*
378	* Disable the transceiver so data isn't actually sent during the
379	* actual test.
380	*/
381
382	UART_PUT_CTRL(port, ctrl & ~(UART_CTRL_TE));
383
384	fifosize = 1;
385	UART_PUT_CHAR(port, 0);
386
387	/*
388	* So long as transmitting a character increments the tranceivier FIFO
389	* length the FIFO must be at least that big. These bytes will
390	* automatically drain off of the FIFO.
391	*/
392
393	status = UART_GET_STATUS(port);
394	while (((status >> 20) & 0x3F) == fifosize) {
395	fifosize++;
396	UART_PUT_CHAR(port, 0);
397	status = UART_GET_STATUS(port);
398	}
399
400	fifosize--;
401
402	UART_PUT_CTRL(port, ctrl);
403	local_irq_restore(flags);
404
405	if (fifosize == 0)
406	fifosize = 1;
407
408	return fifosize;
409	}
410
411	static void apbuart_flush_fifo(struct uart_port *port)
412	{
413	int i;
414
415	for (i = 0; i < port->fifosize; i++)
416	UART_GET_CHAR(port);
417	}
418
419
420	/* ======================================================================== */
421	/* Console driver, if enabled */
422	/* ======================================================================== */
423
424	#ifdef CONFIG_SERIAL_GRLIB_GAISLER_APBUART_CONSOLE
425
426	static void apbuart_console_putchar(struct uart_port *port, int ch)
427	{
428	unsigned int status;
429	do {
430	status = UART_GET_STATUS(port);
431	} while (!UART_TX_READY(status));
432	UART_PUT_CHAR(port, ch);
433	}
434
435	static void
436	apbuart_console_write(struct console co, const char s, unsigned int count)
437	{
438	struct uart_port *port = &grlib_apbuart_ports[co->index];
439	unsigned int status, old_cr, new_cr;
440
441	/* First save the CR then disable the interrupts */
442	old_cr = UART_GET_CTRL(port);
443	new_cr = old_cr & ~(UART_CTRL_RI \| UART_CTRL_TI);
444	UART_PUT_CTRL(port, new_cr);
445
446	uart_console_write(port, s, count, apbuart_console_putchar);
447
448	/*
449	* Finally, wait for transmitter to become empty
450	* and restore the TCR
451	*/
452	do {
453	status = UART_GET_STATUS(port);
454	} while (!UART_TX_READY(status));
455	UART_PUT_CTRL(port, old_cr);
456	}
457
458	static void __init
459	apbuart_console_get_options(struct uart_port port, int baud,
460	int parity, int bits)
461	{
462	if (UART_GET_CTRL(port) & (UART_CTRL_RE \| UART_CTRL_TE)) {
463
464	unsigned int quot, status;
465	status = UART_GET_STATUS(port);
466
467	*parity = 'n';
468	if (status & UART_CTRL_PE) {
469	if ((status & UART_CTRL_PS) == 0)
470	*parity = 'e';
471	else
472	*parity = 'o';
473	}
474
475	*bits = 8;
476	quot = UART_GET_SCAL(port) / 8;
477	baud = port->uartclk / (16 (quot + 1));
478	}
479	}
480
481	static int __init apbuart_console_setup(struct console co, char options)
482	{
483	struct uart_port *port;
484	int baud = 38400;
485	int bits = 8;
486	int parity = 'n';
487	int flow = 'n';
488
489	pr_debug("apbuart_console_setup co=%p, co->index=%i, options=%s\n",
490	co, co->index, options);
491
492	/*
493	* Check whether an invalid uart number has been specified, and
494	* if so, search for the first available port that does have
495	* console support.
496	*/
497	if (co->index >= grlib_apbuart_port_nr)
498	co->index = 0;
499
500	port = &grlib_apbuart_ports[co->index];
501
502	spin_lock_init(&port->lock);
503
504	if (options)
505	uart_parse_options(options, &baud, &parity, &bits, &flow);
506	else
507	apbuart_console_get_options(port, &baud, &parity, &bits);
508
509	return uart_set_options(port, co, baud, parity, bits, flow);
510	}
511
512	static struct uart_driver grlib_apbuart_driver;
513
514	static struct console grlib_apbuart_console = {
515	.name = "ttyS",
516	.write = apbuart_console_write,
517	.device = uart_console_device,
518	.setup = apbuart_console_setup,
519	.flags = CON_PRINTBUFFER,
520	.index = -1,
521	.data = &grlib_apbuart_driver,
522	};
523
524
568389c2	525	static int grlib_apbuart_configure(void);
d4ac42a5 KG	526
	527	static int __init apbuart_console_init(void)
	528	{
568389c2 TG	529	if (grlib_apbuart_configure())
568389c2 TG	530	return -ENODEV;
d4ac42a5 KG	531	register_console(&grlib_apbuart_console);
	532	return 0;
	533	}
	534
	535	console_initcall(apbuart_console_init);
	536
	537	#define APBUART_CONSOLE (&grlib_apbuart_console)
	538	#else
	539	#define APBUART_CONSOLE NULL
	540	#endif
	541
	542	static struct uart_driver grlib_apbuart_driver = {
	543	.owner = THIS_MODULE,
	544	.driver_name = "serial",
	545	.dev_name = "ttyS",
	546	.major = SERIAL_APBUART_MAJOR,
	547	.minor = SERIAL_APBUART_MINOR,
	548	.nr = UART_NR,
	549	.cons = APBUART_CONSOLE,
	550	};
	551
	552
	553	/* ======================================================================== */
	554	/* OF Platform Driver */
	555	/* ======================================================================== */
	556
9671f099	557	static int apbuart_probe(struct platform_device *op)
d4ac42a5	558	{
10544f12	559	int i;
d4ac42a5 KG	560	struct uart_port *port = NULL;
d4ac42a5 KG	561
d4ac42a5	562	for (i = 0; i < grlib_apbuart_port_nr; i++) {
61c7a080	563	if (op->dev.of_node == grlib_apbuart_nodes[i])
d4ac42a5 KG	564	break;
	565	}
	566
	567	port = &grlib_apbuart_ports[i];
	568	port->dev = &op->dev;
10544f12	569	port->irq = op->archdata.irqs[0];
d4ac42a5 KG	570
	571	uart_add_one_port(&grlib_apbuart_driver, (struct uart_port *) port);
	572
	573	apbuart_flush_fifo((struct uart_port *) port);
	574
384a17b2 DM	575	printk(KERN_INFO "grlib-apbuart at 0x%llx, irq %d\n",
384a17b2 DM	576	(unsigned long long) port->mapbase, port->irq);
d4ac42a5	577	return 0;
d4ac42a5 KG	578	}
d4ac42a5 KG	579
ab17da5c	580	static struct of_device_id apbuart_match[] = {
d4ac42a5 KG	581	{
	582	.name = "GAISLER_APBUART",
	583	},
d89ddf0d DH	584	{
	585	.name = "01_00c",
	586	},
d4ac42a5 KG	587	{},
	588	};
	589
793218df	590	static struct platform_driver grlib_apbuart_of_driver = {
d4ac42a5 KG	591	.probe = apbuart_probe,
d4ac42a5 KG	592	.driver = {
4018294b GL	593	.owner = THIS_MODULE,
	594	.name = "grlib-apbuart",
	595	.of_match_table = apbuart_match,
	596	},
d4ac42a5 KG	597	};
	598
	599
ab17da5c	600	static int __init grlib_apbuart_configure(void)
d4ac42a5	601	{
c897dcf6 DH	602	struct device_node *np;
c897dcf6 DH	603	int line = 0;
d4ac42a5	604
d4ac42a5	605	for_each_matching_node(np, apbuart_match) {
10544f12	606	const int *ampopts;
c897dcf6	607	const u32 *freq_hz;
35c64e5d TG	608	const struct amba_prom_registers *regs;
	609	struct uart_port *port;
	610	unsigned long addr;
d4ac42a5	611
56b85f32	612	ampopts = of_get_property(np, "ampopts", NULL);
f28f3313 DH	613	if (ampopts && (*ampopts == 0))
f28f3313 DH	614	continue; /* Ignore if used by another OS instance */
35c64e5d	615	regs = of_get_property(np, "reg", NULL);
c897dcf6 DH	616	/* Frequency of APB Bus is frequency of UART */
c897dcf6 DH	617	freq_hz = of_get_property(np, "freq", NULL);
d4ac42a5	618
c897dcf6	619	if (!regs \|\| !freq_hz \|\| (*freq_hz == 0))
56b85f32	620	continue;
d4ac42a5 KG	621
	622	grlib_apbuart_nodes[line] = np;
	623
	624	addr = regs->phys_addr;
d4ac42a5 KG	625
	626	port = &grlib_apbuart_ports[line];
	627
	628	port->mapbase = addr;
	629	port->membase = ioremap(addr, sizeof(struct grlib_apbuart_regs_map));
10544f12	630	port->irq = 0;
d4ac42a5 KG	631	port->iotype = UPIO_MEM;
	632	port->ops = &grlib_apbuart_ops;
	633	port->flags = UPF_BOOT_AUTOCONF;
	634	port->line = line;
c897dcf6	635	port->uartclk = *freq_hz;
d4ac42a5 KG	636	port->fifosize = apbuart_scan_fifo_size((struct uart_port *) port, line);
	637	line++;
	638
	639	/* We support maximum UART_NR uarts ... */
	640	if (line == UART_NR)
	641	break;
d4ac42a5 KG	642	}
d4ac42a5 KG	643
d4ac42a5	644	grlib_apbuart_driver.nr = grlib_apbuart_port_nr = line;
35c64e5d	645	return line ? 0 : -ENODEV;
d4ac42a5 KG	646	}
	647
	648	static int __init grlib_apbuart_init(void)
	649	{
	650	int ret;
	651
	652	/* Find all APBUARTS in device the tree and initialize their ports */
35c64e5d TG	653	ret = grlib_apbuart_configure();
	654	if (ret)
	655	return ret;
d4ac42a5 KG	656
	657	printk(KERN_INFO "Serial: GRLIB APBUART driver\n");
	658
	659	ret = uart_register_driver(&grlib_apbuart_driver);
	660
	661	if (ret) {
	662	printk(KERN_ERR "%s: uart_register_driver failed (%i)\n",
	663	__FILE__, ret);
	664	return ret;
	665	}
	666
793218df	667	ret = platform_driver_register(&grlib_apbuart_of_driver);
d4ac42a5 KG	668	if (ret) {
d4ac42a5 KG	669	printk(KERN_ERR
793218df	670	"%s: platform_driver_register failed (%i)\n",
d4ac42a5 KG	671	__FILE__, ret);
	672	uart_unregister_driver(&grlib_apbuart_driver);
	673	return ret;
	674	}
	675
	676	return ret;
	677	}
	678
	679	static void __exit grlib_apbuart_exit(void)
	680	{
	681	int i;
	682
	683	for (i = 0; i < grlib_apbuart_port_nr; i++)
	684	uart_remove_one_port(&grlib_apbuart_driver,
	685	&grlib_apbuart_ports[i]);
	686
	687	uart_unregister_driver(&grlib_apbuart_driver);
793218df	688	platform_driver_unregister(&grlib_apbuart_of_driver);
d4ac42a5 KG	689	}
	690
	691	module_init(grlib_apbuart_init);
	692	module_exit(grlib_apbuart_exit);
	693
	694	MODULE_AUTHOR("Aeroflex Gaisler AB");
	695	MODULE_DESCRIPTION("GRLIB APBUART serial driver");
	696	MODULE_VERSION("2.1");
	697	MODULE_LICENSE("GPL");