sunsu.c

来自「Linux Kernel 2.6.9 for OMAP1710」· C语言 代码 · 共 1,741 行 · 第 1/3 页

/* $Id: su.c,v 1.55 2002/01/08 16:00:16 davem Exp $
 * su.c: Small serial driver for keyboard/mouse interface on sparc32/PCI
 *
 * Copyright (C) 1997  Eddie C. Dost  ([e-mail])
 * Copyright (C) 1998-1999  Pete Zaitcev   ([e-mail])
 *
 * This is mainly a variation of 8250.c, credits go to authors mentioned
 * therein.  In fact this driver should be merged into the generic 8250.c
 * infrastructure perhaps using a 8250_sparc.c module.
 *
 * Fixed to use tty_get_baud_rate().
 *   Theodore Ts'o <[e-mail]>, 2001-Oct-12
 *
 * Converted to new 2.5.x UART layer.
 *   David S. Miller ([e-mail]), 2002-Jul-29
 */

#include <linux/config.h>
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/sched.h>
#include <linux/spinlock.h>
#include <linux/errno.h>
#include <linux/tty.h>
#include <linux/tty_flip.h>
#include <linux/major.h>
#include <linux/string.h>
#include <linux/ptrace.h>
#include <linux/ioport.h>
#include <linux/circ_buf.h>
#include <linux/serial.h>
#include <linux/sysrq.h>
#include <linux/console.h>
#ifdef CONFIG_SERIO
#include <linux/serio.h>
#endif
#include <linux/serial_reg.h>
#include <linux/init.h>
#include <linux/delay.h>

#include <asm/io.h>
#include <asm/irq.h>
#include <asm/oplib.h>
#include <asm/ebus.h>
#ifdef CONFIG_SPARC64
#include <asm/isa.h>
#endif

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

#include <linux/serial_core.h>

#include "suncore.h"

/* We are on a NS PC87303 clocked with 24.0 MHz, which results
 * in a UART clock of 1.8462 MHz.
 */
#define SU_BASE_BAUD	(1846200 / 16)

enum su_type { SU_PORT_NONE, SU_PORT_MS, SU_PORT_KBD, SU_PORT_PORT };
static char *su_typev[] = { "su(???)", "su(mouse)", "su(kbd)", "su(serial)" };

/*
 * Here we define the default xmit fifo size used for each type of UART.
 */
static const struct serial_uart_config uart_config[PORT_MAX_8250+1] = {
	{ "unknown",	1,	0 },
	{ "8250",	1,	0 },
	{ "16450",	1,	0 },
	{ "16550",	1,	0 },
	{ "16550A",	16,	UART_CLEAR_FIFO | UART_USE_FIFO },
	{ "Cirrus",	1, 	0 },
	{ "ST16650",	1,	UART_CLEAR_FIFO | UART_STARTECH },
	{ "ST16650V2",	32,	UART_CLEAR_FIFO | UART_USE_FIFO | UART_STARTECH },
	{ "TI16750",	64,	UART_CLEAR_FIFO | UART_USE_FIFO },
	{ "Startech",	1,	0 },
	{ "16C950/954",	128,	UART_CLEAR_FIFO | UART_USE_FIFO },
	{ "ST16654",	64,	UART_CLEAR_FIFO | UART_USE_FIFO | UART_STARTECH },
	{ "XR16850",	128,	UART_CLEAR_FIFO | UART_USE_FIFO | UART_STARTECH },
	{ "RSA",	2048,	UART_CLEAR_FIFO | UART_USE_FIFO }
};

struct uart_sunsu_port {
	struct uart_port	port;
	unsigned char		acr;
	unsigned char		ier;
	unsigned short		rev;
	unsigned char		lcr;
	unsigned int		lsr_break_flag;
	unsigned int		cflag;

	/* Probing information.  */
	enum su_type		su_type;
	unsigned int		type_probed;	/* XXX Stupid */
	int			port_node;
	unsigned int		irq;

#ifdef CONFIG_SERIO
	struct serio		*serio;
	int			serio_open;
#endif
};

#define _INLINE_

static _INLINE_ unsigned int serial_in(struct uart_sunsu_port *up, int offset)
{
	offset <<= up->port.regshift;

	switch (up->port.iotype) {
	case SERIAL_IO_HUB6:
		outb(up->port.hub6 - 1 + offset, up->port.iobase);
		return inb(up->port.iobase + 1);

	case SERIAL_IO_MEM:
		return readb(up->port.membase + offset);

	default:
		return inb(up->port.iobase + offset);
	}
}

static _INLINE_ void
serial_out(struct uart_sunsu_port *up, int offset, int value)
{
#ifndef CONFIG_SPARC64
	/*
	 * MrCoffee has weird schematics: IRQ4 & P10(?) pins of SuperIO are
	 * connected with a gate then go to SlavIO. When IRQ4 goes tristated
	 * gate outputs a logical one. Since we use level triggered interrupts
	 * we have lockup and watchdog reset. We cannot mask IRQ because
	 * keyboard shares IRQ with us (Word has it as Bob Smelik's design).
	 * This problem is similar to what Alpha people suffer, see serial.c.
	 */
	if (offset == UART_MCR)
		value |= UART_MCR_OUT2;
#endif
	offset <<= up->port.regshift;

	switch (up->port.iotype) {
	case SERIAL_IO_HUB6:
		outb(up->port.hub6 - 1 + offset, up->port.iobase);
		outb(value, up->port.iobase + 1);
		break;

	case SERIAL_IO_MEM:
		writeb(value, up->port.membase + offset);
		break;

	default:
		outb(value, up->port.iobase + offset);
	}
}

/*
 * We used to support using pause I/O for certain machines.  We
 * haven't supported this for a while, but just in case it's badly
 * needed for certain old 386 machines, I've left these #define's
 * in....
 */
#define serial_inp(up, offset)		serial_in(up, offset)
#define serial_outp(up, offset, value)	serial_out(up, offset, value)


/*
 * For the 16C950
 */
static void serial_icr_write(struct uart_sunsu_port *up, int offset, int value)
{
	serial_out(up, UART_SCR, offset);
	serial_out(up, UART_ICR, value);
}

#if 0 /* Unused currently */
static unsigned int serial_icr_read(struct uart_sunsu_port *up, int offset)
{
	unsigned int value;

	serial_icr_write(up, UART_ACR, up->acr | UART_ACR_ICRRD);
	serial_out(up, UART_SCR, offset);
	value = serial_in(up, UART_ICR);
	serial_icr_write(up, UART_ACR, up->acr);

	return value;
}
#endif

#ifdef CONFIG_SERIAL_8250_RSA
/*
 * Attempts to turn on the RSA FIFO.  Returns zero on failure.
 * We set the port uart clock rate if we succeed.
 */
static int __enable_rsa(struct uart_sunsu_port *up)
{
	unsigned char mode;
	int result;

	mode = serial_inp(up, UART_RSA_MSR);
	result = mode & UART_RSA_MSR_FIFO;

	if (!result) {
		serial_outp(up, UART_RSA_MSR, mode | UART_RSA_MSR_FIFO);
		mode = serial_inp(up, UART_RSA_MSR);
		result = mode & UART_RSA_MSR_FIFO;
	}

	if (result)
		up->port.uartclk = SERIAL_RSA_BAUD_BASE * 16;

	return result;
}

static void enable_rsa(struct uart_sunsu_port *up)
{
	if (up->port.type == PORT_RSA) {
		if (up->port.uartclk != SERIAL_RSA_BAUD_BASE * 16) {
			spin_lock_irq(&up->port.lock);
			__enable_rsa(up);
			spin_unlock_irq(&up->port.lock);
		}
		if (up->port.uartclk == SERIAL_RSA_BAUD_BASE * 16)
			serial_outp(up, UART_RSA_FRR, 0);
	}
}

/*
 * Attempts to turn off the RSA FIFO.  Returns zero on failure.
 * It is unknown why interrupts were disabled in here.  However,
 * the caller is expected to preserve this behaviour by grabbing
 * the spinlock before calling this function.
 */
static void disable_rsa(struct uart_sunsu_port *up)
{
	unsigned char mode;
	int result;

	if (up->port.type == PORT_RSA &&
	    up->port.uartclk == SERIAL_RSA_BAUD_BASE * 16) {
		spin_lock_irq(&up->port.lock);

		mode = serial_inp(up, UART_RSA_MSR);
		result = !(mode & UART_RSA_MSR_FIFO);

		if (!result) {
			serial_outp(up, UART_RSA_MSR, mode & ~UART_RSA_MSR_FIFO);
			mode = serial_inp(up, UART_RSA_MSR);
			result = !(mode & UART_RSA_MSR_FIFO);
		}

		if (result)
			up->port.uartclk = SERIAL_RSA_BAUD_BASE_LO * 16;
		spin_unlock_irq(&up->port.lock);
	}
}
#endif /* CONFIG_SERIAL_8250_RSA */

static void sunsu_stop_tx(struct uart_port *port, unsigned int tty_stop)
{
	struct uart_sunsu_port *up = (struct uart_sunsu_port *) port;

	if (up->ier & UART_IER_THRI) {
		up->ier &= ~UART_IER_THRI;
		serial_out(up, UART_IER, up->ier);
	}
	if (up->port.type == PORT_16C950 && tty_stop) {
		up->acr |= UART_ACR_TXDIS;
		serial_icr_write(up, UART_ACR, up->acr);
	}
}

static void sunsu_start_tx(struct uart_port *port, unsigned int tty_start)
{
	struct uart_sunsu_port *up = (struct uart_sunsu_port *) port;

	if (!(up->ier & UART_IER_THRI)) {
		up->ier |= UART_IER_THRI;
		serial_out(up, UART_IER, up->ier);
	}
	/*
	 * We only do this from uart_start
	 */
	if (tty_start && up->port.type == PORT_16C950) {
		up->acr &= ~UART_ACR_TXDIS;
		serial_icr_write(up, UART_ACR, up->acr);
	}
}

static void sunsu_stop_rx(struct uart_port *port)
{
	struct uart_sunsu_port *up = (struct uart_sunsu_port *) port;
	unsigned long flags;

	spin_lock_irqsave(&up->port.lock, flags);
	up->ier &= ~UART_IER_RLSI;
	up->port.read_status_mask &= ~UART_LSR_DR;
	serial_out(up, UART_IER, up->ier);
	spin_unlock_irqrestore(&up->port.lock, flags);
}

static void sunsu_enable_ms(struct uart_port *port)
{
	struct uart_sunsu_port *up = (struct uart_sunsu_port *) port;
	unsigned long flags;

	spin_lock_irqsave(&up->port.lock, flags);
	up->ier |= UART_IER_MSI;
	serial_out(up, UART_IER, up->ier);
	spin_unlock_irqrestore(&up->port.lock, flags);
}

static _INLINE_ struct tty_struct *
receive_chars(struct uart_sunsu_port *up, unsigned char *status, struct pt_regs *regs)
{
	struct tty_struct *tty = up->port.info->tty;
	unsigned char ch;
	int max_count = 256;
	int saw_console_brk = 0;

	do {
		if (unlikely(tty->flip.count >= TTY_FLIPBUF_SIZE)) {
			tty->flip.work.func((void *)tty);
			if (tty->flip.count >= TTY_FLIPBUF_SIZE)
				return tty; // if TTY_DONT_FLIP is set
		}
		ch = serial_inp(up, UART_RX);
		*tty->flip.char_buf_ptr = ch;
		*tty->flip.flag_buf_ptr = TTY_NORMAL;
		up->port.icount.rx++;

		if (unlikely(*status & (UART_LSR_BI | UART_LSR_PE |
				       UART_LSR_FE | UART_LSR_OE))) {
			/*
			 * For statistics only
			 */
			if (*status & UART_LSR_BI) {
				*status &= ~(UART_LSR_FE | UART_LSR_PE);
				up->port.icount.brk++;
				if (up->port.cons != NULL &&
				    up->port.line == up->port.cons->index)
					saw_console_brk = 1;
				/*
				 * We do the SysRQ and SAK checking
				 * here because otherwise the break
				 * may get masked by ignore_status_mask
				 * or read_status_mask.
				 */
				if (uart_handle_break(&up->port))
					goto ignore_char;
			} else if (*status & UART_LSR_PE)
				up->port.icount.parity++;
			else if (*status & UART_LSR_FE)
				up->port.icount.frame++;
			if (*status & UART_LSR_OE)
				up->port.icount.overrun++;

			/*
			 * Mask off conditions which should be ingored.
			 */
			*status &= up->port.read_status_mask;

			if (up->port.cons != NULL &&
			    up->port.line == up->port.cons->index) {
				/* Recover the break flag from console xmit */
				*status |= up->lsr_break_flag;
				up->lsr_break_flag = 0;
			}

			if (*status & UART_LSR_BI) {
				*tty->flip.flag_buf_ptr = TTY_BREAK;
			} else if (*status & UART_LSR_PE)
				*tty->flip.flag_buf_ptr = TTY_PARITY;
			else if (*status & UART_LSR_FE)
				*tty->flip.flag_buf_ptr = TTY_FRAME;
		}
		if (uart_handle_sysrq_char(&up->port, ch, regs))
			goto ignore_char;
		if ((*status & up->port.ignore_status_mask) == 0) {
			tty->flip.flag_buf_ptr++;
			tty->flip.char_buf_ptr++;
			tty->flip.count++;
		}
		if ((*status & UART_LSR_OE) &&
		    tty->flip.count < TTY_FLIPBUF_SIZE) {
			/*
			 * Overrun is special, since it's reported
			 * immediately, and doesn't affect the current
			 * character.
			 */
			*tty->flip.flag_buf_ptr = TTY_OVERRUN;
			tty->flip.flag_buf_ptr++;
			tty->flip.char_buf_ptr++;
			tty->flip.count++;
		}
	ignore_char:
		*status = serial_inp(up, UART_LSR);
	} while ((*status & UART_LSR_DR) && (max_count-- > 0));

	if (saw_console_brk)
		sun_do_break();

	return tty;
}

static _INLINE_ void transmit_chars(struct uart_sunsu_port *up)
{
	struct circ_buf *xmit = &up->port.info->xmit;
	int count;

	if (up->port.x_char) {
		serial_outp(up, UART_TX, up->port.x_char);
		up->port.icount.tx++;
		up->port.x_char = 0;
		return;
	}
	if (uart_circ_empty(xmit) || uart_tx_stopped(&up->port)) {
		sunsu_stop_tx(&up->port, 0);
		return;
	}

	count = up->port.fifosize;
	do {
		serial_out(up, UART_TX, xmit->buf[xmit->tail]);
		xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
		up->port.icount.tx++;
		if (uart_circ_empty(xmit))
			break;
	} while (--count > 0);

	if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
		uart_write_wakeup(&up->port);

	if (uart_circ_empty(xmit))
		sunsu_stop_tx(&up->port, 0);
}

static _INLINE_ void check_modem_status(struct uart_sunsu_port *up)
{
	int status;

	status = serial_in(up, UART_MSR);

	if ((status & UART_MSR_ANY_DELTA) == 0)
		return;

	if (status & UART_MSR_TERI)
		up->port.icount.rng++;
	if (status & UART_MSR_DDSR)
		up->port.icount.dsr++;
	if (status & UART_MSR_DDCD)
		uart_handle_dcd_change(&up->port, status & UART_MSR_DCD);
	if (status & UART_MSR_DCTS)
		uart_handle_cts_change(&up->port, status & UART_MSR_CTS);

	wake_up_interruptible(&up->port.info->delta_msr_wait);
}

static irqreturn_t sunsu_serial_interrupt(int irq, void *dev_id, struct pt_regs *regs)
{
	struct uart_sunsu_port *up = dev_id;
	unsigned long flags;
	unsigned char status;

	spin_lock_irqsave(&up->port.lock, flags);

	do {
		struct tty_struct *tty;

		status = serial_inp(up, UART_LSR);
		tty = NULL;
		if (status & UART_LSR_DR)
			tty = receive_chars(up, &status, regs);
		check_modem_status(up);
		if (status & UART_LSR_THRE)
			transmit_chars(up);

		spin_unlock_irqrestore(&up->port.lock, flags);

		if (tty)
			tty_flip_buffer_push(tty);

		spin_lock_irqsave(&up->port.lock, flags);

	} while (!(serial_in(up, UART_IIR) & UART_IIR_NO_INT));

	spin_unlock_irqrestore(&up->port.lock, flags);

	return IRQ_HANDLED;
}

/* Separate interrupt handling path for keyboard/mouse ports.  */

static void
sunsu_change_speed(struct uart_port *port, unsigned int cflag,
		   unsigned int iflag, unsigned int quot);

static void sunsu_change_mouse_baud(struct uart_sunsu_port *up)
{
	unsigned int cur_cflag = up->cflag;
	int quot, new_baud;

	up->cflag &= ~CBAUD;
	up->cflag |= suncore_mouse_baud_cflag_next(cur_cflag, &new_baud);

	quot = up->port.uartclk / (16 * new_baud);

	spin_unlock(&up->port.lock);

	sunsu_change_speed(&up->port, up->cflag, 0, quot);

	spin_lock(&up->port.lock);
}

static void receive_kbd_ms_chars(struct uart_sunsu_port *up, struct pt_regs *regs, int is_break)
{
	do {
		unsigned char ch = serial_inp(up, UART_RX);

		/* Stop-A is handled by drivers/char/keyboard.c now. */
		if (up->su_type == SU_PORT_KBD) {
#ifdef CONFIG_SERIO
			serio_interrupt(up->serio, ch, 0, regs);
#endif
		} else if (up->su_type == SU_PORT_MS) {
			int ret = suncore_mouse_baud_detection(ch, is_break);

			switch (ret) {
			case 2:
				sunsu_change_mouse_baud(up);
				/* fallthru */
			case 1:
				break;

			case 0:
#ifdef CONFIG_SERIO
				serio_interrupt(up->serio, ch, 0, regs);
#endif
				break;
			};
		}
	} while (serial_in(up, UART_LSR) & UART_LSR_DR);
}

static irqreturn_t sunsu_kbd_ms_interrupt(int irq, void *dev_id, struct pt_regs *regs)
{
	struct uart_sunsu_port *up = dev_id;

	if (!(serial_in(up, UART_IIR) & UART_IIR_NO_INT)) {
		unsigned char status = serial_inp(up, UART_LSR);

		if ((status & UART_LSR_DR) || (status & UART_LSR_BI))
			receive_kbd_ms_chars(up, regs,
					     (status & UART_LSR_BI) != 0);
	}

	return IRQ_HANDLED;
}

static unsigned int sunsu_tx_empty(struct uart_port *port)
{
	struct uart_sunsu_port *up = (struct uart_sunsu_port *) port;
	unsigned long flags;
	unsigned int ret;

	spin_lock_irqsave(&up->port.lock, flags);
	ret = serial_in(up, UART_LSR) & UART_LSR_TEMT ? TIOCSER_TEMT : 0;
	spin_unlock_irqrestore(&up->port.lock, flags);

	return ret;
}

static unsigned int sunsu_get_mctrl(struct uart_port *port)
{
	struct uart_sunsu_port *up = (struct uart_sunsu_port *) port;
	unsigned long flags;
	unsigned char status;
	unsigned int ret;

	spin_lock_irqsave(&up->port.lock, flags);
	status = serial_in(up, UART_MSR);