[deliverable/linux.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/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 __devinit apbuart_probe(struct platform_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->dev.of_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",
	 },
	{
	 .name = "01_00c",
	 },
	{},
};

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


static int grlib_apbuart_configure(void)
{
	struct device_node *np, *rp;
	const u32 *prop;
	int freq_khz, line = 0;

	/* Get bus frequency */
	rp = of_find_node_by_path("/");
	if (!rp)
		return -ENODEV;
	rp = of_get_next_child(rp, NULL);
	if (!rp)
		return -ENODEV;
	prop = of_get_property(rp, "clock-frequency", NULL);
	if (!prop)
		return -ENODEV;
	freq_khz = *prop;

	for_each_matching_node(np, apbuart_match) {
		const int *irqs, *ampopts;
		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 */

		irqs = of_get_property(np, "interrupts", NULL);
		regs = of_get_property(np, "reg", NULL);

		if (!irqs || !regs)
			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 = *irqs;
		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;
	}

	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 = of_register_platform_driver(&grlib_apbuart_of_driver);
	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);
	of_unregister_platform_driver(&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>
	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>
ddaf1b27	28	#include <linux/of_platform.h>
f28f3313	29	#include <linux/of_irq.h>
d4ac42a5 KG	30	#include <linux/platform_device.h>
	31	#include <linux/io.h>
	32	#include <linux/serial_core.h>
	33	#include <asm/irq.h>
d4ac42a5 KG	34
	35	#include "apbuart.h"
	36
	37	#define SERIAL_APBUART_MAJOR TTY_MAJOR
	38	#define SERIAL_APBUART_MINOR 64
	39	#define UART_DUMMY_RSR_RX 0x8000 /* for ignore all read */
	40
	41	static void apbuart_tx_chars(struct uart_port *port);
	42
	43	static void apbuart_stop_tx(struct uart_port *port)
	44	{
	45	unsigned int cr;
	46
	47	cr = UART_GET_CTRL(port);
	48	cr &= ~UART_CTRL_TI;
	49	UART_PUT_CTRL(port, cr);
	50	}
	51
	52	static void apbuart_start_tx(struct uart_port *port)
	53	{
	54	unsigned int cr;
	55
	56	cr = UART_GET_CTRL(port);
	57	cr \|= UART_CTRL_TI;
	58	UART_PUT_CTRL(port, cr);
	59
	60	if (UART_GET_STATUS(port) & UART_STATUS_THE)
	61	apbuart_tx_chars(port);
	62	}
	63
	64	static void apbuart_stop_rx(struct uart_port *port)
	65	{
	66	unsigned int cr;
	67
	68	cr = UART_GET_CTRL(port);
	69	cr &= ~(UART_CTRL_RI);
	70	UART_PUT_CTRL(port, cr);
	71	}
	72
	73	static void apbuart_enable_ms(struct uart_port *port)
	74	{
	75	/* No modem status change interrupts for APBUART */
	76	}
	77
	78	static void apbuart_rx_chars(struct uart_port *port)
	79	{
	80	struct tty_struct *tty = port->state->port.tty;
	81	unsigned int status, ch, rsr, flag;
	82	unsigned int max_chars = port->fifosize;
	83
	84	status = UART_GET_STATUS(port);
	85
	86	while (UART_RX_DATA(status) && (max_chars--)) {
	87
	88	ch = UART_GET_CHAR(port);
	89	flag = TTY_NORMAL;
	90
	91	port->icount.rx++;
	92
	93	rsr = UART_GET_STATUS(port) \| UART_DUMMY_RSR_RX;
	94	UART_PUT_STATUS(port, 0);
	95	if (rsr & UART_STATUS_ERR) {
	96
	97	if (rsr & UART_STATUS_BR) {
98	rsr &= ~(UART_STATUS_FE \| UART_STATUS_PE);
99	port->icount.brk++;
100	if (uart_handle_break(port))
101	goto ignore_char;
102	} else if (rsr & UART_STATUS_PE) {
103	port->icount.parity++;
104	} else if (rsr & UART_STATUS_FE) {
105	port->icount.frame++;
106	}
107	if (rsr & UART_STATUS_OE)
108	port->icount.overrun++;
109
110	rsr &= port->read_status_mask;
111
112	if (rsr & UART_STATUS_PE)
113	flag = TTY_PARITY;
114	else if (rsr & UART_STATUS_FE)
115	flag = TTY_FRAME;
116	}
117
118	if (uart_handle_sysrq_char(port, ch))
119	goto ignore_char;
120
121	uart_insert_char(port, rsr, UART_STATUS_OE, ch, flag);
122
123
124	ignore_char:
125	status = UART_GET_STATUS(port);
126	}
127
128	tty_flip_buffer_push(tty);
129	}
130
131	static void apbuart_tx_chars(struct uart_port *port)
132	{
133	struct circ_buf *xmit = &port->state->xmit;
134	int count;
135
136	if (port->x_char) {
137	UART_PUT_CHAR(port, port->x_char);
138	port->icount.tx++;
139	port->x_char = 0;
140	return;
141	}
142
143	if (uart_circ_empty(xmit) \|\| uart_tx_stopped(port)) {
144	apbuart_stop_tx(port);
145	return;
146	}
147
148	/* amba: fill FIFO */
149	count = port->fifosize >> 1;
150	do {
151	UART_PUT_CHAR(port, xmit->buf[xmit->tail]);
152	xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
153	port->icount.tx++;
154	if (uart_circ_empty(xmit))
155	break;
156	} while (--count > 0);
157
158	if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
159	uart_write_wakeup(port);
160
161	if (uart_circ_empty(xmit))
162	apbuart_stop_tx(port);
163	}
164
165	static irqreturn_t apbuart_int(int irq, void *dev_id)
166	{
167	struct uart_port *port = dev_id;
168	unsigned int status;
169
170	spin_lock(&port->lock);
171
172	status = UART_GET_STATUS(port);
173	if (status & UART_STATUS_DR)
174	apbuart_rx_chars(port);
175	if (status & UART_STATUS_THE)
176	apbuart_tx_chars(port);
177
178	spin_unlock(&port->lock);
179
180	return IRQ_HANDLED;
181	}
182
183	static unsigned int apbuart_tx_empty(struct uart_port *port)
184	{
185	unsigned int status = UART_GET_STATUS(port);
186	return status & UART_STATUS_THE ? TIOCSER_TEMT : 0;
187	}
188
189	static unsigned int apbuart_get_mctrl(struct uart_port *port)
190	{
191	/* The GRLIB APBUART handles flow control in hardware */
192	return TIOCM_CAR \| TIOCM_DSR \| TIOCM_CTS;
193	}
194
195	static void apbuart_set_mctrl(struct uart_port *port, unsigned int mctrl)
196	{
197	/* The GRLIB APBUART handles flow control in hardware */
198	}
199
200	static void apbuart_break_ctl(struct uart_port *port, int break_state)
201	{
202	/* We don't support sending break */
203	}
204
205	static int apbuart_startup(struct uart_port *port)
206	{
207	int retval;
208	unsigned int cr;
209
210	/* Allocate the IRQ */
211	retval = request_irq(port->irq, apbuart_int, 0, "apbuart", port);
212	if (retval)
213	return retval;
214
215	/* Finally, enable interrupts */
216	cr = UART_GET_CTRL(port);
217	UART_PUT_CTRL(port,
218	cr \| UART_CTRL_RE \| UART_CTRL_TE \|
219	UART_CTRL_RI \| UART_CTRL_TI);
220
221	return 0;
222	}
223
224	static void apbuart_shutdown(struct uart_port *port)
225	{
226	unsigned int cr;
227
228	/* disable all interrupts, disable the port */
229	cr = UART_GET_CTRL(port);
230	UART_PUT_CTRL(port,
231	cr & ~(UART_CTRL_RE \| UART_CTRL_TE \|
232	UART_CTRL_RI \| UART_CTRL_TI));
233
234	/* Free the interrupt */
235	free_irq(port->irq, port);
236	}
237
238	static void apbuart_set_termios(struct uart_port *port,
239	struct ktermios termios, struct ktermios old)
240	{
241	unsigned int cr;
242	unsigned long flags;
243	unsigned int baud, quot;
244
245	/* Ask the core to calculate the divisor for us. */
246	baud = uart_get_baud_rate(port, termios, old, 0, port->uartclk / 16);
247	if (baud == 0)
248	panic("invalid baudrate %i\n", port->uartclk / 16);
249
250	/* uart_get_divisor calc a 16 uart freq, apbuart is 8 */
251	quot = (uart_get_divisor(port, baud)) * 2;
252	cr = UART_GET_CTRL(port);
253	cr &= ~(UART_CTRL_PE \| UART_CTRL_PS);
254
255	if (termios->c_cflag & PARENB) {
256	cr \|= UART_CTRL_PE;
257	if ((termios->c_cflag & PARODD))
258	cr \|= UART_CTRL_PS;
259	}
260
261	/* Enable flow control. */
262	if (termios->c_cflag & CRTSCTS)
263	cr \|= UART_CTRL_FL;
264
265	spin_lock_irqsave(&port->lock, flags);
266
267	/* Update the per-port timeout. */
268	uart_update_timeout(port, termios->c_cflag, baud);
269
270	port->read_status_mask = UART_STATUS_OE;
271	if (termios->c_iflag & INPCK)
272	port->read_status_mask \|= UART_STATUS_FE \| UART_STATUS_PE;
273
274	/* Characters to ignore */
275	port->ignore_status_mask = 0;
276	if (termios->c_iflag & IGNPAR)
277	port->ignore_status_mask \|= UART_STATUS_FE \| UART_STATUS_PE;
278
279	/* Ignore all characters if CREAD is not set. */
280	if ((termios->c_cflag & CREAD) == 0)
281	port->ignore_status_mask \|= UART_DUMMY_RSR_RX;
282
283	/* Set baud rate */
284	quot -= 1;
285	UART_PUT_SCAL(port, quot);
286	UART_PUT_CTRL(port, cr);
287
288	spin_unlock_irqrestore(&port->lock, flags);
289	}
290
291	static const char apbuart_type(struct uart_port port)
292	{
293	return port->type == PORT_APBUART ? "GRLIB/APBUART" : NULL;
294	}
295
296	static void apbuart_release_port(struct uart_port *port)
297	{
298	release_mem_region(port->mapbase, 0x100);
299	}
300
301	static int apbuart_request_port(struct uart_port *port)
302	{
303	return request_mem_region(port->mapbase, 0x100, "grlib-apbuart")
304	!= NULL ? 0 : -EBUSY;
305	return 0;
306	}
307
308	/* Configure/autoconfigure the port */
309	static void apbuart_config_port(struct uart_port *port, int flags)
310	{
311	if (flags & UART_CONFIG_TYPE) {
312	port->type = PORT_APBUART;
313	apbuart_request_port(port);
314	}
315	}
316
317	/* Verify the new serial_struct (for TIOCSSERIAL) */
318	static int apbuart_verify_port(struct uart_port *port,
319	struct serial_struct *ser)
320	{
321	int ret = 0;
322	if (ser->type != PORT_UNKNOWN && ser->type != PORT_APBUART)
323	ret = -EINVAL;
324	if (ser->irq < 0 \|\| ser->irq >= NR_IRQS)
325	ret = -EINVAL;
326	if (ser->baud_base < 9600)
327	ret = -EINVAL;
328	return ret;
329	}
330
331	static struct uart_ops grlib_apbuart_ops = {
332	.tx_empty = apbuart_tx_empty,
333	.set_mctrl = apbuart_set_mctrl,
334	.get_mctrl = apbuart_get_mctrl,
335	.stop_tx = apbuart_stop_tx,
336	.start_tx = apbuart_start_tx,
337	.stop_rx = apbuart_stop_rx,
338	.enable_ms = apbuart_enable_ms,
339	.break_ctl = apbuart_break_ctl,
340	.startup = apbuart_startup,
341	.shutdown = apbuart_shutdown,
342	.set_termios = apbuart_set_termios,
343	.type = apbuart_type,
344	.release_port = apbuart_release_port,
345	.request_port = apbuart_request_port,
346	.config_port = apbuart_config_port,
347	.verify_port = apbuart_verify_port,
348	};
349
350	static struct uart_port grlib_apbuart_ports[UART_NR];
351	static struct device_node *grlib_apbuart_nodes[UART_NR];
352
353	static int apbuart_scan_fifo_size(struct uart_port *port, int portnumber)
354	{
355	int ctrl, loop = 0;
356	int status;
357	int fifosize;
358	unsigned long flags;
359
360	ctrl = UART_GET_CTRL(port);
361
362	/*
363	* Enable the transceiver and wait for it to be ready to send data.
364	* Clear interrupts so that this process will not be externally
365	* interrupted in the middle (which can cause the transceiver to
366	* drain prematurely).
367	*/
368
369	local_irq_save(flags);
370
371	UART_PUT_CTRL(port, ctrl \| UART_CTRL_TE);
372
373	while (!UART_TX_READY(UART_GET_STATUS(port)))
374	loop++;
375
376	/*
377	* Disable the transceiver so data isn't actually sent during the
378	* actual test.
379	*/
380
381	UART_PUT_CTRL(port, ctrl & ~(UART_CTRL_TE));
382
383	fifosize = 1;
384	UART_PUT_CHAR(port, 0);
385
386	/*
387	* So long as transmitting a character increments the tranceivier FIFO
388	* length the FIFO must be at least that big. These bytes will
389	* automatically drain off of the FIFO.
390	*/
391
392	status = UART_GET_STATUS(port);
393	while (((status >> 20) & 0x3F) == fifosize) {
394	fifosize++;
395	UART_PUT_CHAR(port, 0);
396	status = UART_GET_STATUS(port);
397	}
398
399	fifosize--;
400
401	UART_PUT_CTRL(port, ctrl);
402	local_irq_restore(flags);
403
404	if (fifosize == 0)
405	fifosize = 1;
406
407	return fifosize;
408	}
409
410	static void apbuart_flush_fifo(struct uart_port *port)
411	{
412	int i;
413
414	for (i = 0; i < port->fifosize; i++)
415	UART_GET_CHAR(port);
416	}
417
418
419	/* ======================================================================== */
420	/* Console driver, if enabled */
421	/* ======================================================================== */
422
423	#ifdef CONFIG_SERIAL_GRLIB_GAISLER_APBUART_CONSOLE
424
425	static void apbuart_console_putchar(struct uart_port *port, int ch)
426	{
427	unsigned int status;
428	do {
429	status = UART_GET_STATUS(port);
430	} while (!UART_TX_READY(status));
431	UART_PUT_CHAR(port, ch);
432	}
433
434	static void
435	apbuart_console_write(struct console co, const char s, unsigned int count)
436	{
437	struct uart_port *port = &grlib_apbuart_ports[co->index];
438	unsigned int status, old_cr, new_cr;
439
440	/* First save the CR then disable the interrupts */
441	old_cr = UART_GET_CTRL(port);
442	new_cr = old_cr & ~(UART_CTRL_RI \| UART_CTRL_TI);
443	UART_PUT_CTRL(port, new_cr);
444
445	uart_console_write(port, s, count, apbuart_console_putchar);
446
447	/*
448	* Finally, wait for transmitter to become empty
449	* and restore the TCR
450	*/
451	do {
452	status = UART_GET_STATUS(port);
453	} while (!UART_TX_READY(status));
454	UART_PUT_CTRL(port, old_cr);
455	}
456
457	static void __init
458	apbuart_console_get_options(struct uart_port port, int baud,
459	int parity, int bits)
460	{
461	if (UART_GET_CTRL(port) & (UART_CTRL_RE \| UART_CTRL_TE)) {
462
463	unsigned int quot, status;
464	status = UART_GET_STATUS(port);
465
466	*parity = 'n';
467	if (status & UART_CTRL_PE) {
468	if ((status & UART_CTRL_PS) == 0)
469	*parity = 'e';
470	else
471	*parity = 'o';
472	}
473
474	*bits = 8;
475	quot = UART_GET_SCAL(port) / 8;
476	baud = port->uartclk / (16 (quot + 1));
477	}
478	}
479
480	static int __init apbuart_console_setup(struct console co, char options)
481	{
482	struct uart_port *port;
483	int baud = 38400;
484	int bits = 8;
485	int parity = 'n';
486	int flow = 'n';
487
488	pr_debug("apbuart_console_setup co=%p, co->index=%i, options=%s\n",
489	co, co->index, options);
490
491	/*
492	* Check whether an invalid uart number has been specified, and
493	* if so, search for the first available port that does have
494	* console support.
495	*/
496	if (co->index >= grlib_apbuart_port_nr)
497	co->index = 0;
498
499	port = &grlib_apbuart_ports[co->index];
500
501	spin_lock_init(&port->lock);
502
503	if (options)
504	uart_parse_options(options, &baud, &parity, &bits, &flow);
505	else
506	apbuart_console_get_options(port, &baud, &parity, &bits);
507
508	return uart_set_options(port, co, baud, parity, bits, flow);
509	}
510
511	static struct uart_driver grlib_apbuart_driver;
512
513	static struct console grlib_apbuart_console = {
514	.name = "ttyS",
515	.write = apbuart_console_write,
516	.device = uart_console_device,
517	.setup = apbuart_console_setup,
518	.flags = CON_PRINTBUFFER,
519	.index = -1,
520	.data = &grlib_apbuart_driver,
521	};
522
523
568389c2	524	static int grlib_apbuart_configure(void);
d4ac42a5 KG	525
	526	static int __init apbuart_console_init(void)
	527	{
568389c2 TG	528	if (grlib_apbuart_configure())
568389c2 TG	529	return -ENODEV;
d4ac42a5 KG	530	register_console(&grlib_apbuart_console);
	531	return 0;
	532	}
	533
	534	console_initcall(apbuart_console_init);
	535
	536	#define APBUART_CONSOLE (&grlib_apbuart_console)
	537	#else
	538	#define APBUART_CONSOLE NULL
	539	#endif
	540
	541	static struct uart_driver grlib_apbuart_driver = {
	542	.owner = THIS_MODULE,
	543	.driver_name = "serial",
	544	.dev_name = "ttyS",
	545	.major = SERIAL_APBUART_MAJOR,
	546	.minor = SERIAL_APBUART_MINOR,
	547	.nr = UART_NR,
	548	.cons = APBUART_CONSOLE,
	549	};
	550
	551
	552	/* ======================================================================== */
	553	/* OF Platform Driver */
	554	/* ======================================================================== */
	555
2dc11581	556	static int __devinit apbuart_probe(struct platform_device *op,
d4ac42a5 KG	557	const struct of_device_id *match)
	558	{
	559	int i = -1;
	560	struct uart_port *port = NULL;
	561
	562	i = 0;
	563	for (i = 0; i < grlib_apbuart_port_nr; i++) {
61c7a080	564	if (op->dev.of_node == grlib_apbuart_nodes[i])
d4ac42a5 KG	565	break;
	566	}
	567
	568	port = &grlib_apbuart_ports[i];
	569	port->dev = &op->dev;
	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	}
	579
	580	static struct of_device_id __initdata apbuart_match[] = {
	581	{
	582	.name = "GAISLER_APBUART",
	583	},
d89ddf0d DH	584	{
	585	.name = "01_00c",
	586	},
d4ac42a5 KG	587	{},
	588	};
	589
	590	static struct of_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
35c64e5d	600	static int grlib_apbuart_configure(void)
d4ac42a5	601	{
d1350098	602	struct device_node np, rp;
d1350098	603	const u32 *prop;
35c64e5d	604	int freq_khz, line = 0;
d4ac42a5 KG	605
d4ac42a5 KG	606	/* Get bus frequency */
4edd5ad0	607	rp = of_find_node_by_path("/");
35c64e5d TG	608	if (!rp)
35c64e5d TG	609	return -ENODEV;
d1350098	610	rp = of_get_next_child(rp, NULL);
35c64e5d TG	611	if (!rp)
35c64e5d TG	612	return -ENODEV;
d1350098	613	prop = of_get_property(rp, "clock-frequency", NULL);
35c64e5d TG	614	if (!prop)
35c64e5d TG	615	return -ENODEV;
d1350098	616	freq_khz = *prop;
d4ac42a5	617
d4ac42a5	618	for_each_matching_node(np, apbuart_match) {
56b85f32	619	const int irqs, ampopts;
35c64e5d TG	620	const struct amba_prom_registers *regs;
	621	struct uart_port *port;
	622	unsigned long addr;
d4ac42a5	623
56b85f32	624	ampopts = of_get_property(np, "ampopts", NULL);
f28f3313 DH	625	if (ampopts && (*ampopts == 0))
f28f3313 DH	626	continue; /* Ignore if used by another OS instance */
56b85f32 LT	627
56b85f32 LT	628	irqs = of_get_property(np, "interrupts", NULL);
35c64e5d	629	regs = of_get_property(np, "reg", NULL);
d4ac42a5 KG	630
d4ac42a5 KG	631	if (!irqs \|\| !regs)
56b85f32	632	continue;
d4ac42a5 KG	633
	634	grlib_apbuart_nodes[line] = np;
	635
	636	addr = regs->phys_addr;
d4ac42a5 KG	637
	638	port = &grlib_apbuart_ports[line];
	639
	640	port->mapbase = addr;
	641	port->membase = ioremap(addr, sizeof(struct grlib_apbuart_regs_map));
35c64e5d	642	port->irq = *irqs;
d4ac42a5 KG	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;
d4ac42a5 KG	654	}
d4ac42a5 KG	655
d4ac42a5	656	grlib_apbuart_driver.nr = grlib_apbuart_port_nr = line;
35c64e5d	657	return line ? 0 : -ENODEV;
d4ac42a5 KG	658	}
	659
	660	static int __init grlib_apbuart_init(void)
	661	{
	662	int ret;
	663
	664	/* Find all APBUARTS in device the tree and initialize their ports */
35c64e5d TG	665	ret = grlib_apbuart_configure();
	666	if (ret)
	667	return ret;
d4ac42a5 KG	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
ddaf1b27	679	ret = of_register_platform_driver(&grlib_apbuart_of_driver);
d4ac42a5 KG	680	if (ret) {
	681	printk(KERN_ERR
	682	"%s: of_register_platform_driver failed (%i)\n",
	683	__FILE__, ret);
	684	uart_unregister_driver(&grlib_apbuart_driver);
	685	return ret;
	686	}
	687
	688	return ret;
	689	}
	690
	691	static void __exit grlib_apbuart_exit(void)
	692	{
	693	int i;
	694
	695	for (i = 0; i < grlib_apbuart_port_nr; i++)
	696	uart_remove_one_port(&grlib_apbuart_driver,
	697	&grlib_apbuart_ports[i]);
	698
	699	uart_unregister_driver(&grlib_apbuart_driver);
ddaf1b27	700	of_unregister_platform_driver(&grlib_apbuart_of_driver);
d4ac42a5 KG	701	}
	702
	703	module_init(grlib_apbuart_init);
	704	module_exit(grlib_apbuart_exit);
	705
	706	MODULE_AUTHOR("Aeroflex Gaisler AB");
	707	MODULE_DESCRIPTION("GRLIB APBUART serial driver");
	708	MODULE_VERSION("2.1");
	709	MODULE_LICENSE("GPL");