[linux-block.git] / drivers / 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/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/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 void grlib_apbuart_configure(void);

static int __init apbuart_console_init(void)
{
	grlib_apbuart_configure();
	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 __devinit apbuart_probe(struct of_device *op,
				   const struct of_device_id *match)
{
	int i = -1;
	struct uart_port *port = NULL;

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

	port = &grlib_apbuart_ports[i];
	port->dev = &op->dev;

	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 __initdata apbuart_match[] = {
	{
	 .name = "GAISLER_APBUART",
	 },
	{},
};

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


static void grlib_apbuart_configure(void)
{
	static int enum_done;
	struct device_node *np, *rp;
	struct uart_port *port = NULL;
	const u32 *prop;
	int freq_khz;
	int v = 0, d = 0;
	unsigned int addr;
	int irq, line;
	struct amba_prom_registers *regs;

	if (enum_done)
		return;

	/* Get bus frequency */
	rp = of_find_node_by_name(NULL, "/");
	rp = of_get_next_child(rp, NULL);
	prop = of_get_property(rp, "clock-frequency", NULL);
	freq_khz = *prop;

	line = 0;
	for_each_matching_node(np, apbuart_match) {

		int *vendor = (int *) of_get_property(np, "vendor", NULL);
		int *device = (int *) of_get_property(np, "device", NULL);
		int *irqs = (int *) of_get_property(np, "interrupts", NULL);
		regs = (struct amba_prom_registers *)
		    of_get_property(np, "reg", NULL);

		if (vendor)
			v = *vendor;
		if (device)
			d = *device;

		if (!irqs || !regs)
			return;

		grlib_apbuart_nodes[line] = np;

		addr = regs->phys_addr;
		irq = *irqs;

		port = &grlib_apbuart_ports[line];

		port->mapbase = addr;
		port->membase = ioremap(addr, sizeof(struct grlib_apbuart_regs_map));
		port->irq = irq;
		port->iotype = UPIO_MEM;
		port->ops = &grlib_apbuart_ops;
		port->flags = UPF_BOOT_AUTOCONF;
		port->line = line;
		port->uartclk = freq_khz * 1000;
		port->fifosize = apbuart_scan_fifo_size((struct uart_port *) port, line);
		line++;

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

	}

	enum_done = 1;

	grlib_apbuart_driver.nr = grlib_apbuart_port_nr = line;
}

static int __init grlib_apbuart_init(void)
{
	int ret;

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

	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 = of_register_driver(&grlib_apbuart_of_driver, &of_platform_bus_type);

	if (ret) {
		printk(KERN_ERR
		       "%s: of_register_platform_driver 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);

}

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>
	19	#include <linux/ioport.h>
	20	#include <linux/init.h>
	21	#include <linux/serial.h>
	22	#include <linux/console.h>
	23	#include <linux/sysrq.h>
	24	#include <linux/kthread.h>
	25	#include <linux/device.h>
	26	#include <linux/of.h>
	27	#include <linux/of_device.h>
	28	#include <linux/platform_device.h>
	29	#include <linux/io.h>
	30	#include <linux/serial_core.h>
	31	#include <asm/irq.h>
d4ac42a5 KG	32
	33	#include "apbuart.h"
	34
	35	#define SERIAL_APBUART_MAJOR TTY_MAJOR
	36	#define SERIAL_APBUART_MINOR 64
	37	#define UART_DUMMY_RSR_RX 0x8000 /* for ignore all read */
	38
	39	static void apbuart_tx_chars(struct uart_port *port);
	40
	41	static void apbuart_stop_tx(struct uart_port *port)
	42	{
	43	unsigned int cr;
	44
	45	cr = UART_GET_CTRL(port);
	46	cr &= ~UART_CTRL_TI;
	47	UART_PUT_CTRL(port, cr);
	48	}
	49
	50	static void apbuart_start_tx(struct uart_port *port)
	51	{
	52	unsigned int cr;
	53
	54	cr = UART_GET_CTRL(port);
	55	cr \|= UART_CTRL_TI;
	56	UART_PUT_CTRL(port, cr);
	57
	58	if (UART_GET_STATUS(port) & UART_STATUS_THE)
	59	apbuart_tx_chars(port);
	60	}
	61
	62	static void apbuart_stop_rx(struct uart_port *port)
	63	{
	64	unsigned int cr;
	65
	66	cr = UART_GET_CTRL(port);
	67	cr &= ~(UART_CTRL_RI);
	68	UART_PUT_CTRL(port, cr);
	69	}
	70
	71	static void apbuart_enable_ms(struct uart_port *port)
	72	{
	73	/* No modem status change interrupts for APBUART */
	74	}
	75
	76	static void apbuart_rx_chars(struct uart_port *port)
	77	{
	78	struct tty_struct *tty = port->state->port.tty;
	79	unsigned int status, ch, rsr, flag;
	80	unsigned int max_chars = port->fifosize;
	81
	82	status = UART_GET_STATUS(port);
	83
	84	while (UART_RX_DATA(status) && (max_chars--)) {
	85
	86	ch = UART_GET_CHAR(port);
	87	flag = TTY_NORMAL;
	88
	89	port->icount.rx++;
	90
	91	rsr = UART_GET_STATUS(port) \| UART_DUMMY_RSR_RX;
	92	UART_PUT_STATUS(port, 0);
	93	if (rsr & UART_STATUS_ERR) {
	94
	95	if (rsr & UART_STATUS_BR) {
96	rsr &= ~(UART_STATUS_FE \| UART_STATUS_PE);
97	port->icount.brk++;
98	if (uart_handle_break(port))
99	goto ignore_char;
100	} else if (rsr & UART_STATUS_PE) {
101	port->icount.parity++;
102	} else if (rsr & UART_STATUS_FE) {
103	port->icount.frame++;
104	}
105	if (rsr & UART_STATUS_OE)
106	port->icount.overrun++;
107
108	rsr &= port->read_status_mask;
109
110	if (rsr & UART_STATUS_PE)
111	flag = TTY_PARITY;
112	else if (rsr & UART_STATUS_FE)
113	flag = TTY_FRAME;
114	}
115
116	if (uart_handle_sysrq_char(port, ch))
117	goto ignore_char;
118
119	uart_insert_char(port, rsr, UART_STATUS_OE, ch, flag);
120
121
122	ignore_char:
123	status = UART_GET_STATUS(port);
124	}
125
126	tty_flip_buffer_push(tty);
127	}
128
129	static void apbuart_tx_chars(struct uart_port *port)
130	{
131	struct circ_buf *xmit = &port->state->xmit;
132	int count;
133
134	if (port->x_char) {
135	UART_PUT_CHAR(port, port->x_char);
136	port->icount.tx++;
137	port->x_char = 0;
138	return;
139	}
140
141	if (uart_circ_empty(xmit) \|\| uart_tx_stopped(port)) {
142	apbuart_stop_tx(port);
143	return;
144	}
145
146	/* amba: fill FIFO */
147	count = port->fifosize >> 1;
148	do {
149	UART_PUT_CHAR(port, xmit->buf[xmit->tail]);
150	xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
151	port->icount.tx++;
152	if (uart_circ_empty(xmit))
153	break;
154	} while (--count > 0);
155
156	if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
157	uart_write_wakeup(port);
158
159	if (uart_circ_empty(xmit))
160	apbuart_stop_tx(port);
161	}
162
163	static irqreturn_t apbuart_int(int irq, void *dev_id)
164	{
165	struct uart_port *port = dev_id;
166	unsigned int status;
167
168	spin_lock(&port->lock);
169
170	status = UART_GET_STATUS(port);
171	if (status & UART_STATUS_DR)
172	apbuart_rx_chars(port);
173	if (status & UART_STATUS_THE)
174	apbuart_tx_chars(port);
175
176	spin_unlock(&port->lock);
177
178	return IRQ_HANDLED;
179	}
180
181	static unsigned int apbuart_tx_empty(struct uart_port *port)
182	{
183	unsigned int status = UART_GET_STATUS(port);
184	return status & UART_STATUS_THE ? TIOCSER_TEMT : 0;
185	}
186
187	static unsigned int apbuart_get_mctrl(struct uart_port *port)
188	{
189	/* The GRLIB APBUART handles flow control in hardware */
190	return TIOCM_CAR \| TIOCM_DSR \| TIOCM_CTS;
191	}
192
193	static void apbuart_set_mctrl(struct uart_port *port, unsigned int mctrl)
194	{
195	/* The GRLIB APBUART handles flow control in hardware */
196	}
197
198	static void apbuart_break_ctl(struct uart_port *port, int break_state)
199	{
200	/* We don't support sending break */
201	}
202
203	static int apbuart_startup(struct uart_port *port)
204	{
205	int retval;
206	unsigned int cr;
207
208	/* Allocate the IRQ */
209	retval = request_irq(port->irq, apbuart_int, 0, "apbuart", port);
210	if (retval)
211	return retval;
212
213	/* Finally, enable interrupts */
214	cr = UART_GET_CTRL(port);
215	UART_PUT_CTRL(port,
216	cr \| UART_CTRL_RE \| UART_CTRL_TE \|
217	UART_CTRL_RI \| UART_CTRL_TI);
218
219	return 0;
220	}
221
222	static void apbuart_shutdown(struct uart_port *port)
223	{
224	unsigned int cr;
225
226	/* disable all interrupts, disable the port */
227	cr = UART_GET_CTRL(port);
228	UART_PUT_CTRL(port,
229	cr & ~(UART_CTRL_RE \| UART_CTRL_TE \|
230	UART_CTRL_RI \| UART_CTRL_TI));
231
232	/* Free the interrupt */
233	free_irq(port->irq, port);
234	}
235
236	static void apbuart_set_termios(struct uart_port *port,
237	struct ktermios termios, struct ktermios old)
238	{
239	unsigned int cr;
240	unsigned long flags;
241	unsigned int baud, quot;
242
243	/* Ask the core to calculate the divisor for us. */
244	baud = uart_get_baud_rate(port, termios, old, 0, port->uartclk / 16);
245	if (baud == 0)
246	panic("invalid baudrate %i\n", port->uartclk / 16);
247
248	/* uart_get_divisor calc a 16 uart freq, apbuart is 8 */
249	quot = (uart_get_divisor(port, baud)) * 2;
250	cr = UART_GET_CTRL(port);
251	cr &= ~(UART_CTRL_PE \| UART_CTRL_PS);
252
253	if (termios->c_cflag & PARENB) {
254	cr \|= UART_CTRL_PE;
255	if ((termios->c_cflag & PARODD))
256	cr \|= UART_CTRL_PS;
257	}
258
259	/* Enable flow control. */
260	if (termios->c_cflag & CRTSCTS)
261	cr \|= UART_CTRL_FL;
262
263	spin_lock_irqsave(&port->lock, flags);
264
265	/* Update the per-port timeout. */
266	uart_update_timeout(port, termios->c_cflag, baud);
267
268	port->read_status_mask = UART_STATUS_OE;
269	if (termios->c_iflag & INPCK)
270	port->read_status_mask \|= UART_STATUS_FE \| UART_STATUS_PE;
271
272	/* Characters to ignore */
273	port->ignore_status_mask = 0;
274	if (termios->c_iflag & IGNPAR)
275	port->ignore_status_mask \|= UART_STATUS_FE \| UART_STATUS_PE;
276
277	/* Ignore all characters if CREAD is not set. */
278	if ((termios->c_cflag & CREAD) == 0)
279	port->ignore_status_mask \|= UART_DUMMY_RSR_RX;
280
281	/* Set baud rate */
282	quot -= 1;
283	UART_PUT_SCAL(port, quot);
284	UART_PUT_CTRL(port, cr);
285
286	spin_unlock_irqrestore(&port->lock, flags);
287	}
288
289	static const char apbuart_type(struct uart_port port)
290	{
291	return port->type == PORT_APBUART ? "GRLIB/APBUART" : NULL;
292	}
293
294	static void apbuart_release_port(struct uart_port *port)
295	{
296	release_mem_region(port->mapbase, 0x100);
297	}
298
299	static int apbuart_request_port(struct uart_port *port)
300	{
301	return request_mem_region(port->mapbase, 0x100, "grlib-apbuart")
302	!= NULL ? 0 : -EBUSY;
303	return 0;
304	}
305
306	/* Configure/autoconfigure the port */
307	static void apbuart_config_port(struct uart_port *port, int flags)
308	{
309	if (flags & UART_CONFIG_TYPE) {
310	port->type = PORT_APBUART;
311	apbuart_request_port(port);
312	}
313	}
314
315	/* Verify the new serial_struct (for TIOCSSERIAL) */
316	static int apbuart_verify_port(struct uart_port *port,
317	struct serial_struct *ser)
318	{
319	int ret = 0;
320	if (ser->type != PORT_UNKNOWN && ser->type != PORT_APBUART)
321	ret = -EINVAL;
322	if (ser->irq < 0 \|\| ser->irq >= NR_IRQS)
323	ret = -EINVAL;
324	if (ser->baud_base < 9600)
325	ret = -EINVAL;
326	return ret;
327	}
328
329	static struct uart_ops grlib_apbuart_ops = {
330	.tx_empty = apbuart_tx_empty,
331	.set_mctrl = apbuart_set_mctrl,
332	.get_mctrl = apbuart_get_mctrl,
333	.stop_tx = apbuart_stop_tx,
334	.start_tx = apbuart_start_tx,
335	.stop_rx = apbuart_stop_rx,
336	.enable_ms = apbuart_enable_ms,
337	.break_ctl = apbuart_break_ctl,
338	.startup = apbuart_startup,
339	.shutdown = apbuart_shutdown,
340	.set_termios = apbuart_set_termios,
341	.type = apbuart_type,
342	.release_port = apbuart_release_port,
343	.request_port = apbuart_request_port,
344	.config_port = apbuart_config_port,
345	.verify_port = apbuart_verify_port,
346	};
347
348	static struct uart_port grlib_apbuart_ports[UART_NR];
349	static struct device_node *grlib_apbuart_nodes[UART_NR];
350
351	static int apbuart_scan_fifo_size(struct uart_port *port, int portnumber)
352	{
353	int ctrl, loop = 0;
354	int status;
355	int fifosize;
356	unsigned long flags;
357
358	ctrl = UART_GET_CTRL(port);
359
360	/*
361	* Enable the transceiver and wait for it to be ready to send data.
362	* Clear interrupts so that this process will not be externally
363	* interrupted in the middle (which can cause the transceiver to
364	* drain prematurely).
365	*/
366
367	local_irq_save(flags);
368
369	UART_PUT_CTRL(port, ctrl \| UART_CTRL_TE);
370
371	while (!UART_TX_READY(UART_GET_STATUS(port)))
372	loop++;
373
374	/*
375	* Disable the transceiver so data isn't actually sent during the
376	* actual test.
377	*/
378
379	UART_PUT_CTRL(port, ctrl & ~(UART_CTRL_TE));
380
381	fifosize = 1;
382	UART_PUT_CHAR(port, 0);
383
384	/*
385	* So long as transmitting a character increments the tranceivier FIFO
386	* length the FIFO must be at least that big. These bytes will
387	* automatically drain off of the FIFO.
388	*/
389
390	status = UART_GET_STATUS(port);
391	while (((status >> 20) & 0x3F) == fifosize) {
392	fifosize++;
393	UART_PUT_CHAR(port, 0);
394	status = UART_GET_STATUS(port);
395	}
396
397	fifosize--;
398
399	UART_PUT_CTRL(port, ctrl);
400	local_irq_restore(flags);
401
402	if (fifosize == 0)
403	fifosize = 1;
404
405	return fifosize;
406	}
407
408	static void apbuart_flush_fifo(struct uart_port *port)
409	{
410	int i;
411
412	for (i = 0; i < port->fifosize; i++)
413	UART_GET_CHAR(port);
414	}
415
416
417	/* ======================================================================== */
418	/* Console driver, if enabled */
419	/* ======================================================================== */
420
421	#ifdef CONFIG_SERIAL_GRLIB_GAISLER_APBUART_CONSOLE
422
423	static void apbuart_console_putchar(struct uart_port *port, int ch)
424	{
425	unsigned int status;
426	do {
427	status = UART_GET_STATUS(port);
428	} while (!UART_TX_READY(status));
429	UART_PUT_CHAR(port, ch);
430	}
431
432	static void
433	apbuart_console_write(struct console co, const char s, unsigned int count)
434	{
435	struct uart_port *port = &grlib_apbuart_ports[co->index];
436	unsigned int status, old_cr, new_cr;
437
438	/* First save the CR then disable the interrupts */
439	old_cr = UART_GET_CTRL(port);
440	new_cr = old_cr & ~(UART_CTRL_RI \| UART_CTRL_TI);
441	UART_PUT_CTRL(port, new_cr);
442
443	uart_console_write(port, s, count, apbuart_console_putchar);
444
445	/*
446	* Finally, wait for transmitter to become empty
447	* and restore the TCR
448	*/
449	do {
450	status = UART_GET_STATUS(port);
451	} while (!UART_TX_READY(status));
452	UART_PUT_CTRL(port, old_cr);
453	}
454
455	static void __init
456	apbuart_console_get_options(struct uart_port port, int baud,
457	int parity, int bits)
458	{
459	if (UART_GET_CTRL(port) & (UART_CTRL_RE \| UART_CTRL_TE)) {
460
461	unsigned int quot, status;
462	status = UART_GET_STATUS(port);
463
464	*parity = 'n';
465	if (status & UART_CTRL_PE) {
466	if ((status & UART_CTRL_PS) == 0)
467	*parity = 'e';
468	else
469	*parity = 'o';
470	}
471
472	*bits = 8;
473	quot = UART_GET_SCAL(port) / 8;
474	baud = port->uartclk / (16 (quot + 1));
475	}
476	}
477
478	static int __init apbuart_console_setup(struct console co, char options)
479	{
480	struct uart_port *port;
481	int baud = 38400;
482	int bits = 8;
483	int parity = 'n';
484	int flow = 'n';
485
486	pr_debug("apbuart_console_setup co=%p, co->index=%i, options=%s\n",
487	co, co->index, options);
488
489	/*
490	* Check whether an invalid uart number has been specified, and
491	* if so, search for the first available port that does have
492	* console support.
493	*/
494	if (co->index >= grlib_apbuart_port_nr)
495	co->index = 0;
496
497	port = &grlib_apbuart_ports[co->index];
498
499	spin_lock_init(&port->lock);
500
501	if (options)
502	uart_parse_options(options, &baud, &parity, &bits, &flow);
503	else
504	apbuart_console_get_options(port, &baud, &parity, &bits);
505
506	return uart_set_options(port, co, baud, parity, bits, flow);
507	}
508
509	static struct uart_driver grlib_apbuart_driver;
510
511	static struct console grlib_apbuart_console = {
512	.name = "ttyS",
513	.write = apbuart_console_write,
514	.device = uart_console_device,
515	.setup = apbuart_console_setup,
516	.flags = CON_PRINTBUFFER,
517	.index = -1,
518	.data = &grlib_apbuart_driver,
519	};
520
521
522	static void grlib_apbuart_configure(void);
523
524	static int __init apbuart_console_init(void)
525	{
526	grlib_apbuart_configure();
527	register_console(&grlib_apbuart_console);
528	return 0;
529	}
530
531	console_initcall(apbuart_console_init);
532
533	#define APBUART_CONSOLE (&grlib_apbuart_console)
534	#else
535	#define APBUART_CONSOLE NULL
536	#endif
537
538	static struct uart_driver grlib_apbuart_driver = {
539	.owner = THIS_MODULE,
540	.driver_name = "serial",
541	.dev_name = "ttyS",
542	.major = SERIAL_APBUART_MAJOR,
543	.minor = SERIAL_APBUART_MINOR,
544	.nr = UART_NR,
545	.cons = APBUART_CONSOLE,
546	};
547
548
549	/* ======================================================================== */
550	/* OF Platform Driver */
551	/* ======================================================================== */
552
553	static int __devinit apbuart_probe(struct of_device *op,
554	const struct of_device_id *match)
555	{
556	int i = -1;
557	struct uart_port *port = NULL;
558
559	i = 0;
560	for (i = 0; i < grlib_apbuart_port_nr; i++) {
561	if (op->node == grlib_apbuart_nodes[i])
562	break;
563	}
564
565	port = &grlib_apbuart_ports[i];
566	port->dev = &op->dev;
567
568	uart_add_one_port(&grlib_apbuart_driver, (struct uart_port *) port);
569
570	apbuart_flush_fifo((struct uart_port *) port);
571
384a17b2 DM	572	printk(KERN_INFO "grlib-apbuart at 0x%llx, irq %d\n",
384a17b2 DM	573	(unsigned long long) port->mapbase, port->irq);
d4ac42a5 KG	574	return 0;
	575
	576	}
	577
	578	static struct of_device_id __initdata apbuart_match[] = {
	579	{
	580	.name = "GAISLER_APBUART",
	581	},
	582	{},
	583	};
	584
	585	static struct of_platform_driver grlib_apbuart_of_driver = {
	586	.match_table = apbuart_match,
	587	.probe = apbuart_probe,
	588	.driver = {
	589	.owner = THIS_MODULE,
	590	.name = "grlib-apbuart",
	591	},
	592	};
	593
	594
	595	static void grlib_apbuart_configure(void)
	596	{
	597	static int enum_done;
d1350098	598	struct device_node np, rp;
d4ac42a5	599	struct uart_port *port = NULL;
d1350098	600	const u32 *prop;
d4ac42a5 KG	601	int freq_khz;
	602	int v = 0, d = 0;
	603	unsigned int addr;
	604	int irq, line;
	605	struct amba_prom_registers *regs;
	606
	607	if (enum_done)
	608	return;
	609
	610	/* Get bus frequency */
d1350098 DM	611	rp = of_find_node_by_name(NULL, "/");
	612	rp = of_get_next_child(rp, NULL);
	613	prop = of_get_property(rp, "clock-frequency", NULL);
	614	freq_khz = *prop;
d4ac42a5 KG	615
	616	line = 0;
	617	for_each_matching_node(np, apbuart_match) {
	618
	619	int vendor = (int ) of_get_property(np, "vendor", NULL);
	620	int device = (int ) of_get_property(np, "device", NULL);
	621	int irqs = (int ) of_get_property(np, "interrupts", NULL);
	622	regs = (struct amba_prom_registers *)
	623	of_get_property(np, "reg", NULL);
	624
	625	if (vendor)
	626	v = *vendor;
	627	if (device)
	628	d = *device;
	629
	630	if (!irqs \|\| !regs)
	631	return;
	632
	633	grlib_apbuart_nodes[line] = np;
	634
	635	addr = regs->phys_addr;
	636	irq = *irqs;
	637
	638	port = &grlib_apbuart_ports[line];
	639
	640	port->mapbase = addr;
	641	port->membase = ioremap(addr, sizeof(struct grlib_apbuart_regs_map));
	642	port->irq = irq;
	643	port->iotype = UPIO_MEM;
	644	port->ops = &grlib_apbuart_ops;
	645	port->flags = UPF_BOOT_AUTOCONF;
	646	port->line = line;
	647	port->uartclk = freq_khz * 1000;
	648	port->fifosize = apbuart_scan_fifo_size((struct uart_port *) port, line);
	649	line++;
	650
	651	/* We support maximum UART_NR uarts ... */
	652	if (line == UART_NR)
	653	break;
	654
	655	}
	656
	657	enum_done = 1;
	658
	659	grlib_apbuart_driver.nr = grlib_apbuart_port_nr = line;
	660	}
	661
	662	static int __init grlib_apbuart_init(void)
	663	{
	664	int ret;
	665
	666	/* Find all APBUARTS in device the tree and initialize their ports */
	667	grlib_apbuart_configure();
	668
	669	printk(KERN_INFO "Serial: GRLIB APBUART driver\n");
	670
	671	ret = uart_register_driver(&grlib_apbuart_driver);
	672
	673	if (ret) {
	674	printk(KERN_ERR "%s: uart_register_driver failed (%i)\n",
	675	__FILE__, ret);
	676	return ret;
	677	}
	678
679	ret = of_register_driver(&grlib_apbuart_of_driver, &of_platform_bus_type);
680
681	if (ret) {
682	printk(KERN_ERR
683	"%s: of_register_platform_driver failed (%i)\n",
684	__FILE__, ret);
685	uart_unregister_driver(&grlib_apbuart_driver);
686	return ret;
687	}
688
689	return ret;
690	}
691
692	static void __exit grlib_apbuart_exit(void)
693	{
694	int i;
695
696	for (i = 0; i < grlib_apbuart_port_nr; i++)
697	uart_remove_one_port(&grlib_apbuart_driver,
698	&grlib_apbuart_ports[i]);
699
700	uart_unregister_driver(&grlib_apbuart_driver);
701
702	}
703
704	module_init(grlib_apbuart_init);
705	module_exit(grlib_apbuart_exit);
706
707	MODULE_AUTHOR("Aeroflex Gaisler AB");
708	MODULE_DESCRIPTION("GRLIB APBUART serial driver");
709	MODULE_VERSION("2.1");
710	MODULE_LICENSE("GPL");