[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)
{
	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);
	}

	spin_unlock(&port->lock);
	tty_flip_buffer_push(&port->state->port);
	spin_lock(&port->lock);
}

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	{
d4ac42a5 KG	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
78d34d75	128	spin_unlock(&port->lock);
2e124b4a	129	tty_flip_buffer_push(&port->state->port);
78d34d75	130	spin_lock(&port->lock);
d4ac42a5 KG	131	}
	132
	133	static void apbuart_tx_chars(struct uart_port *port)
	134	{
	135	struct circ_buf *xmit = &port->state->xmit;
	136	int count;
	137
	138	if (port->x_char) {
	139	UART_PUT_CHAR(port, port->x_char);
	140	port->icount.tx++;
	141	port->x_char = 0;
	142	return;
	143	}
	144
	145	if (uart_circ_empty(xmit) \|\| uart_tx_stopped(port)) {
	146	apbuart_stop_tx(port);
	147	return;
	148	}
	149
	150	/* amba: fill FIFO */
	151	count = port->fifosize >> 1;
	152	do {
	153	UART_PUT_CHAR(port, xmit->buf[xmit->tail]);
	154	xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
	155	port->icount.tx++;
	156	if (uart_circ_empty(xmit))
	157	break;
	158	} while (--count > 0);
	159
	160	if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
	161	uart_write_wakeup(port);
	162
	163	if (uart_circ_empty(xmit))
	164	apbuart_stop_tx(port);
	165	}
	166
	167	static irqreturn_t apbuart_int(int irq, void *dev_id)
	168	{
	169	struct uart_port *port = dev_id;
	170	unsigned int status;
	171
	172	spin_lock(&port->lock);
	173
	174	status = UART_GET_STATUS(port);
	175	if (status & UART_STATUS_DR)
	176	apbuart_rx_chars(port);
	177	if (status & UART_STATUS_THE)
	178	apbuart_tx_chars(port);
	179
	180	spin_unlock(&port->lock);
	181
	182	return IRQ_HANDLED;
	183	}
	184
	185	static unsigned int apbuart_tx_empty(struct uart_port *port)
	186	{
	187	unsigned int status = UART_GET_STATUS(port);
	188	return status & UART_STATUS_THE ? TIOCSER_TEMT : 0;
	189	}
	190
	191	static unsigned int apbuart_get_mctrl(struct uart_port *port)
	192	{
	193	/* The GRLIB APBUART handles flow control in hardware */
	194	return TIOCM_CAR \| TIOCM_DSR \| TIOCM_CTS;
195	}
196
197	static void apbuart_set_mctrl(struct uart_port *port, unsigned int mctrl)
198	{
199	/* The GRLIB APBUART handles flow control in hardware */
200	}
201
202	static void apbuart_break_ctl(struct uart_port *port, int break_state)
203	{
204	/* We don't support sending break */
205	}
206
207	static int apbuart_startup(struct uart_port *port)
208	{
209	int retval;
210	unsigned int cr;
211
212	/* Allocate the IRQ */
213	retval = request_irq(port->irq, apbuart_int, 0, "apbuart", port);
214	if (retval)
215	return retval;
216
217	/* Finally, enable interrupts */
218	cr = UART_GET_CTRL(port);
219	UART_PUT_CTRL(port,
220	cr \| UART_CTRL_RE \| UART_CTRL_TE \|
221	UART_CTRL_RI \| UART_CTRL_TI);
222
223	return 0;
224	}
225
226	static void apbuart_shutdown(struct uart_port *port)
227	{
228	unsigned int cr;
229
230	/* disable all interrupts, disable the port */
231	cr = UART_GET_CTRL(port);
232	UART_PUT_CTRL(port,
233	cr & ~(UART_CTRL_RE \| UART_CTRL_TE \|
234	UART_CTRL_RI \| UART_CTRL_TI));
235
236	/* Free the interrupt */
237	free_irq(port->irq, port);
238	}
239
240	static void apbuart_set_termios(struct uart_port *port,
241	struct ktermios termios, struct ktermios old)
242	{
243	unsigned int cr;
244	unsigned long flags;
245	unsigned int baud, quot;
246
247	/* Ask the core to calculate the divisor for us. */
248	baud = uart_get_baud_rate(port, termios, old, 0, port->uartclk / 16);
249	if (baud == 0)
250	panic("invalid baudrate %i\n", port->uartclk / 16);
251
252	/* uart_get_divisor calc a 16 uart freq, apbuart is 8 */
253	quot = (uart_get_divisor(port, baud)) * 2;
254	cr = UART_GET_CTRL(port);
255	cr &= ~(UART_CTRL_PE \| UART_CTRL_PS);
256
257	if (termios->c_cflag & PARENB) {
258	cr \|= UART_CTRL_PE;
259	if ((termios->c_cflag & PARODD))
260	cr \|= UART_CTRL_PS;
261	}
262
263	/* Enable flow control. */
264	if (termios->c_cflag & CRTSCTS)
265	cr \|= UART_CTRL_FL;
266
267	spin_lock_irqsave(&port->lock, flags);
268
269	/* Update the per-port timeout. */
270	uart_update_timeout(port, termios->c_cflag, baud);
271
272	port->read_status_mask = UART_STATUS_OE;
273	if (termios->c_iflag & INPCK)
274	port->read_status_mask \|= UART_STATUS_FE \| UART_STATUS_PE;
275
276	/* Characters to ignore */
277	port->ignore_status_mask = 0;
278	if (termios->c_iflag & IGNPAR)
279	port->ignore_status_mask \|= UART_STATUS_FE \| UART_STATUS_PE;
280
281	/* Ignore all characters if CREAD is not set. */
282	if ((termios->c_cflag & CREAD) == 0)
283	port->ignore_status_mask \|= UART_DUMMY_RSR_RX;
284
285	/* Set baud rate */
286	quot -= 1;
287	UART_PUT_SCAL(port, quot);
288	UART_PUT_CTRL(port, cr);
289
290	spin_unlock_irqrestore(&port->lock, flags);
291	}
292
293	static const char apbuart_type(struct uart_port port)
294	{
295	return port->type == PORT_APBUART ? "GRLIB/APBUART" : NULL;
296	}
297
298	static void apbuart_release_port(struct uart_port *port)
299	{
300	release_mem_region(port->mapbase, 0x100);
301	}
302
303	static int apbuart_request_port(struct uart_port *port)
304	{
305	return request_mem_region(port->mapbase, 0x100, "grlib-apbuart")
306	!= NULL ? 0 : -EBUSY;
307	return 0;
308	}
309
310	/* Configure/autoconfigure the port */
311	static void apbuart_config_port(struct uart_port *port, int flags)
312	{
313	if (flags & UART_CONFIG_TYPE) {
314	port->type = PORT_APBUART;
315	apbuart_request_port(port);
316	}
317	}
318
319	/* Verify the new serial_struct (for TIOCSSERIAL) */
320	static int apbuart_verify_port(struct uart_port *port,
321	struct serial_struct *ser)
322	{
323	int ret = 0;
324	if (ser->type != PORT_UNKNOWN && ser->type != PORT_APBUART)
325	ret = -EINVAL;
326	if (ser->irq < 0 \|\| ser->irq >= NR_IRQS)
327	ret = -EINVAL;
328	if (ser->baud_base < 9600)
329	ret = -EINVAL;
330	return ret;
331	}
332
333	static struct uart_ops grlib_apbuart_ops = {
334	.tx_empty = apbuart_tx_empty,
335	.set_mctrl = apbuart_set_mctrl,
336	.get_mctrl = apbuart_get_mctrl,
337	.stop_tx = apbuart_stop_tx,
338	.start_tx = apbuart_start_tx,
339	.stop_rx = apbuart_stop_rx,
340	.enable_ms = apbuart_enable_ms,
341	.break_ctl = apbuart_break_ctl,
342	.startup = apbuart_startup,
343	.shutdown = apbuart_shutdown,
344	.set_termios = apbuart_set_termios,
345	.type = apbuart_type,
346	.release_port = apbuart_release_port,
347	.request_port = apbuart_request_port,
348	.config_port = apbuart_config_port,
349	.verify_port = apbuart_verify_port,
350	};
351
352	static struct uart_port grlib_apbuart_ports[UART_NR];
353	static struct device_node *grlib_apbuart_nodes[UART_NR];
354
355	static int apbuart_scan_fifo_size(struct uart_port *port, int portnumber)
356	{
357	int ctrl, loop = 0;
358	int status;
359	int fifosize;
360	unsigned long flags;
361
362	ctrl = UART_GET_CTRL(port);
363
364	/*
365	* Enable the transceiver and wait for it to be ready to send data.
366	* Clear interrupts so that this process will not be externally
367	* interrupted in the middle (which can cause the transceiver to
368	* drain prematurely).
369	*/
370
371	local_irq_save(flags);
372
373	UART_PUT_CTRL(port, ctrl \| UART_CTRL_TE);
374
375	while (!UART_TX_READY(UART_GET_STATUS(port)))
376	loop++;
377
378	/*
379	* Disable the transceiver so data isn't actually sent during the
380	* actual test.
381	*/
382
383	UART_PUT_CTRL(port, ctrl & ~(UART_CTRL_TE));
384
385	fifosize = 1;
386	UART_PUT_CHAR(port, 0);
387
388	/*
389	* So long as transmitting a character increments the tranceivier FIFO
390	* length the FIFO must be at least that big. These bytes will
391	* automatically drain off of the FIFO.
392	*/
393
394	status = UART_GET_STATUS(port);
395	while (((status >> 20) & 0x3F) == fifosize) {
396	fifosize++;
397	UART_PUT_CHAR(port, 0);
398	status = UART_GET_STATUS(port);
399	}
400
401	fifosize--;
402
403	UART_PUT_CTRL(port, ctrl);
404	local_irq_restore(flags);
405
406	if (fifosize == 0)
407	fifosize = 1;
408
409	return fifosize;
410	}
411
412	static void apbuart_flush_fifo(struct uart_port *port)
413	{
414	int i;
415
416	for (i = 0; i < port->fifosize; i++)
417	UART_GET_CHAR(port);
418	}
419
420
421	/* ======================================================================== */
422	/* Console driver, if enabled */
423	/* ======================================================================== */
424
425	#ifdef CONFIG_SERIAL_GRLIB_GAISLER_APBUART_CONSOLE
426
427	static void apbuart_console_putchar(struct uart_port *port, int ch)
428	{
429	unsigned int status;
430	do {
431	status = UART_GET_STATUS(port);
432	} while (!UART_TX_READY(status));
433	UART_PUT_CHAR(port, ch);
434	}
435
436	static void
437	apbuart_console_write(struct console co, const char s, unsigned int count)
438	{
439	struct uart_port *port = &grlib_apbuart_ports[co->index];
440	unsigned int status, old_cr, new_cr;
441
442	/* First save the CR then disable the interrupts */
443	old_cr = UART_GET_CTRL(port);
444	new_cr = old_cr & ~(UART_CTRL_RI \| UART_CTRL_TI);
445	UART_PUT_CTRL(port, new_cr);
446
447	uart_console_write(port, s, count, apbuart_console_putchar);
448
449	/*
450	* Finally, wait for transmitter to become empty
451	* and restore the TCR
452	*/
453	do {
454	status = UART_GET_STATUS(port);
455	} while (!UART_TX_READY(status));
456	UART_PUT_CTRL(port, old_cr);
457	}
458
459	static void __init
460	apbuart_console_get_options(struct uart_port port, int baud,
461	int parity, int bits)
462	{
463	if (UART_GET_CTRL(port) & (UART_CTRL_RE \| UART_CTRL_TE)) {
464
465	unsigned int quot, status;
466	status = UART_GET_STATUS(port);
467
468	*parity = 'n';
469	if (status & UART_CTRL_PE) {
470	if ((status & UART_CTRL_PS) == 0)
471	*parity = 'e';
472	else
473	*parity = 'o';
474	}
475
476	*bits = 8;
477	quot = UART_GET_SCAL(port) / 8;
478	baud = port->uartclk / (16 (quot + 1));
479	}
480	}
481
482	static int __init apbuart_console_setup(struct console co, char options)
483	{
484	struct uart_port *port;
485	int baud = 38400;
486	int bits = 8;
487	int parity = 'n';
488	int flow = 'n';
489
490	pr_debug("apbuart_console_setup co=%p, co->index=%i, options=%s\n",
491	co, co->index, options);
492
493	/*
494	* Check whether an invalid uart number has been specified, and
495	* if so, search for the first available port that does have
496	* console support.
497	*/
498	if (co->index >= grlib_apbuart_port_nr)
499	co->index = 0;
500
501	port = &grlib_apbuart_ports[co->index];
502
503	spin_lock_init(&port->lock);
504
505	if (options)
506	uart_parse_options(options, &baud, &parity, &bits, &flow);
507	else
508	apbuart_console_get_options(port, &baud, &parity, &bits);
509
510	return uart_set_options(port, co, baud, parity, bits, flow);
511	}
512
513	static struct uart_driver grlib_apbuart_driver;
514
515	static struct console grlib_apbuart_console = {
516	.name = "ttyS",
517	.write = apbuart_console_write,
518	.device = uart_console_device,
519	.setup = apbuart_console_setup,
520	.flags = CON_PRINTBUFFER,
521	.index = -1,
522	.data = &grlib_apbuart_driver,
523	};
524
525
568389c2	526	static int grlib_apbuart_configure(void);
d4ac42a5 KG	527
	528	static int __init apbuart_console_init(void)
	529	{
568389c2 TG	530	if (grlib_apbuart_configure())
568389c2 TG	531	return -ENODEV;
d4ac42a5 KG	532	register_console(&grlib_apbuart_console);
	533	return 0;
	534	}
	535
	536	console_initcall(apbuart_console_init);
	537
	538	#define APBUART_CONSOLE (&grlib_apbuart_console)
	539	#else
	540	#define APBUART_CONSOLE NULL
	541	#endif
	542
	543	static struct uart_driver grlib_apbuart_driver = {
	544	.owner = THIS_MODULE,
	545	.driver_name = "serial",
	546	.dev_name = "ttyS",
	547	.major = SERIAL_APBUART_MAJOR,
	548	.minor = SERIAL_APBUART_MINOR,
	549	.nr = UART_NR,
	550	.cons = APBUART_CONSOLE,
	551	};
	552
	553
	554	/* ======================================================================== */
	555	/* OF Platform Driver */
	556	/* ======================================================================== */
	557
9671f099	558	static int apbuart_probe(struct platform_device *op)
d4ac42a5	559	{
10544f12	560	int i;
d4ac42a5 KG	561	struct uart_port *port = NULL;
d4ac42a5 KG	562
d4ac42a5	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;
10544f12	570	port->irq = op->archdata.irqs[0];
d4ac42a5 KG	571
	572	uart_add_one_port(&grlib_apbuart_driver, (struct uart_port *) port);
	573
	574	apbuart_flush_fifo((struct uart_port *) port);
	575
384a17b2 DM	576	printk(KERN_INFO "grlib-apbuart at 0x%llx, irq %d\n",
384a17b2 DM	577	(unsigned long long) port->mapbase, port->irq);
d4ac42a5	578	return 0;
d4ac42a5 KG	579	}
d4ac42a5 KG	580
ab17da5c	581	static struct of_device_id apbuart_match[] = {
d4ac42a5 KG	582	{
	583	.name = "GAISLER_APBUART",
	584	},
d89ddf0d DH	585	{
	586	.name = "01_00c",
	587	},
d4ac42a5 KG	588	{},
	589	};
	590
793218df	591	static struct platform_driver grlib_apbuart_of_driver = {
d4ac42a5 KG	592	.probe = apbuart_probe,
d4ac42a5 KG	593	.driver = {
4018294b GL	594	.owner = THIS_MODULE,
	595	.name = "grlib-apbuart",
	596	.of_match_table = apbuart_match,
	597	},
d4ac42a5 KG	598	};
	599
	600
ab17da5c	601	static int __init grlib_apbuart_configure(void)
d4ac42a5	602	{
c897dcf6 DH	603	struct device_node *np;
c897dcf6 DH	604	int line = 0;
d4ac42a5	605
d4ac42a5	606	for_each_matching_node(np, apbuart_match) {
10544f12	607	const int *ampopts;
c897dcf6	608	const u32 *freq_hz;
35c64e5d TG	609	const struct amba_prom_registers *regs;
	610	struct uart_port *port;
	611	unsigned long addr;
d4ac42a5	612
56b85f32	613	ampopts = of_get_property(np, "ampopts", NULL);
f28f3313 DH	614	if (ampopts && (*ampopts == 0))
f28f3313 DH	615	continue; /* Ignore if used by another OS instance */
35c64e5d	616	regs = of_get_property(np, "reg", NULL);
c897dcf6 DH	617	/* Frequency of APB Bus is frequency of UART */
c897dcf6 DH	618	freq_hz = of_get_property(np, "freq", NULL);
d4ac42a5	619
c897dcf6	620	if (!regs \|\| !freq_hz \|\| (*freq_hz == 0))
56b85f32	621	continue;
d4ac42a5 KG	622
	623	grlib_apbuart_nodes[line] = np;
	624
	625	addr = regs->phys_addr;
d4ac42a5 KG	626
	627	port = &grlib_apbuart_ports[line];
	628
	629	port->mapbase = addr;
	630	port->membase = ioremap(addr, sizeof(struct grlib_apbuart_regs_map));
10544f12	631	port->irq = 0;
d4ac42a5 KG	632	port->iotype = UPIO_MEM;
	633	port->ops = &grlib_apbuart_ops;
	634	port->flags = UPF_BOOT_AUTOCONF;
	635	port->line = line;
c897dcf6	636	port->uartclk = *freq_hz;
d4ac42a5 KG	637	port->fifosize = apbuart_scan_fifo_size((struct uart_port *) port, line);
	638	line++;
	639
	640	/* We support maximum UART_NR uarts ... */
	641	if (line == UART_NR)
	642	break;
d4ac42a5 KG	643	}
d4ac42a5 KG	644
d4ac42a5	645	grlib_apbuart_driver.nr = grlib_apbuart_port_nr = line;
35c64e5d	646	return line ? 0 : -ENODEV;
d4ac42a5 KG	647	}
	648
	649	static int __init grlib_apbuart_init(void)
	650	{
	651	int ret;
	652
	653	/* Find all APBUARTS in device the tree and initialize their ports */
35c64e5d TG	654	ret = grlib_apbuart_configure();
	655	if (ret)
	656	return ret;
d4ac42a5 KG	657
	658	printk(KERN_INFO "Serial: GRLIB APBUART driver\n");
	659
	660	ret = uart_register_driver(&grlib_apbuart_driver);
	661
	662	if (ret) {
	663	printk(KERN_ERR "%s: uart_register_driver failed (%i)\n",
	664	__FILE__, ret);
	665	return ret;
	666	}
	667
793218df	668	ret = platform_driver_register(&grlib_apbuart_of_driver);
d4ac42a5 KG	669	if (ret) {
d4ac42a5 KG	670	printk(KERN_ERR
793218df	671	"%s: platform_driver_register failed (%i)\n",
d4ac42a5 KG	672	__FILE__, ret);
	673	uart_unregister_driver(&grlib_apbuart_driver);
	674	return ret;
	675	}
	676
	677	return ret;
	678	}
	679
	680	static void __exit grlib_apbuart_exit(void)
	681	{
	682	int i;
	683
	684	for (i = 0; i < grlib_apbuart_port_nr; i++)
	685	uart_remove_one_port(&grlib_apbuart_driver,
	686	&grlib_apbuart_ports[i]);
	687
	688	uart_unregister_driver(&grlib_apbuart_driver);
793218df	689	platform_driver_unregister(&grlib_apbuart_of_driver);
d4ac42a5 KG	690	}
	691
	692	module_init(grlib_apbuart_init);
	693	module_exit(grlib_apbuart_exit);
	694
	695	MODULE_AUTHOR("Aeroflex Gaisler AB");
	696	MODULE_DESCRIPTION("GRLIB APBUART serial driver");
	697	MODULE_VERSION("2.1");
	698	MODULE_LICENSE("GPL");