uart00.c

IXP425 平台下嵌入式LINUX的串口的驱动程序

/*
 *  linux/drivers/char/serial_uart00.c
 *
 *  Driver for UART00 serial ports
 *
 *  Based on drivers/char/serial_amba.c, by ARM Limited & 
 *                                          Deep Blue Solutions Ltd.
 *  Copyright 2001 Altera Corporation
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 *
 *  $Id: uart00.c,v 1.3.2.5 2002/10/24 09:53:26 rmk Exp $
 *
 */
#include <linux/config.h>
#include <linux/module.h>

#include <linux/errno.h>
#include <linux/signal.h>
#include <linux/sched.h>
#include <linux/interrupt.h>
#include <linux/tty.h>
#include <linux/tty_flip.h>
#include <linux/major.h>
#include <linux/string.h>
#include <linux/fcntl.h>
#include <linux/ptrace.h>
#include <linux/ioport.h>
#include <linux/mm.h>
#include <linux/slab.h>
#include <linux/init.h>
#include <linux/circ_buf.h>
#include <linux/serial.h>
#include <linux/console.h>
#include <linux/sysrq.h>

#include <asm/system.h>
#include <asm/io.h>
#include <asm/irq.h>
#include <asm/uaccess.h>
#include <asm/bitops.h>
#include <asm/sizes.h>

#if defined(CONFIG_SERIAL_UART00_CONSOLE) && defined(CONFIG_MAGIC_SYSRQ)
#define SUPPORT_SYSRQ
#endif

#include <linux/serial_core.h>
#include <asm/arch/excalibur.h>
#define UART00_TYPE (volatile unsigned int*)
#include <asm/arch/uart00.h>
#include <asm/arch/int_ctrl00.h>

#undef DEBUG
#define UART_NR		2

#define SERIAL_UART00_NAME	"ttyUA"
#define SERIAL_UART00_MAJOR	204
#define SERIAL_UART00_MINOR	16      /* Temporary - will change in future */
#define SERIAL_UART00_NR	UART_NR
#define UART_PORT_SIZE 0x50

#define CALLOUT_UART00_NAME	"cuaua"
#define CALLOUT_UART00_MAJOR	205
#define CALLOUT_UART00_MINOR	16      /* Temporary - will change in future */
#define CALLOUT_UART00_NR	UART_NR



static struct tty_driver normal, callout;
static struct tty_struct *uart00_table[UART_NR];
static struct termios *uart00_termios[UART_NR], *uart00_termios_locked[UART_NR];
//static struct uart_state uart00_state[UART_NR];
static struct console uart00_console;

#define UART00_ISR_PASS_LIMIT	256

/*
 * Access macros for the UART00 UARTs
 */
#define UART_GET_INT_STATUS(p)	inl(UART_ISR((p)->membase))
#define UART_PUT_IES(p, c)      outl(c,UART_IES((p)->membase))
#define UART_GET_IES(p)         inl(UART_IES((p)->membase))
#define UART_PUT_IEC(p, c)      outl(c,UART_IEC((p)->membase))
#define UART_GET_IEC(p)         inl(UART_IEC((p)->membase))
#define UART_PUT_CHAR(p, c)     outl(c,UART_TD((p)->membase))
#define UART_GET_CHAR(p)        inl(UART_RD((p)->membase))
#define UART_GET_RSR(p)         inl(UART_RSR((p)->membase))
#define UART_GET_RDS(p)         inl(UART_RDS((p)->membase))
#define UART_GET_MSR(p)         inl(UART_MSR((p)->membase))
#define UART_GET_MCR(p)         inl(UART_MCR((p)->membase))
#define UART_PUT_MCR(p, c)      outl(c,UART_MCR((p)->membase))
#define UART_GET_MC(p)          inl(UART_MC((p)->membase))
#define UART_PUT_MC(p, c)       outl(c,UART_MC((p)->membase))
#define UART_GET_TSR(p)         inl(UART_TSR((p)->membase))
#define UART_GET_DIV_HI(p)	inl(UART_DIV_HI((p)->membase))
#define UART_PUT_DIV_HI(p,c)	outl(c,UART_DIV_HI((p)->membase))
#define UART_GET_DIV_LO(p)	inl(UART_DIV_LO((p)->membase))
#define UART_PUT_DIV_LO(p,c)	outl(c,UART_DIV_LO((p)->membase))
#define UART_RX_DATA(s)		((s) & UART_RSR_RX_LEVEL_MSK)
#define UART_TX_READY(s)	(((s) & UART_TSR_TX_LEVEL_MSK) < 15)
//#define UART_TX_EMPTY(p)	((UART_GET_FR(p) & UART00_UARTFR_TMSK) == 0)

static void uart00_stop_tx(struct uart_port *port, u_int from_tty)
{

	UART_PUT_IEC(port, UART_IEC_TIE_MSK);
}

static void uart00_stop_rx(struct uart_port *port)
{

	UART_PUT_IEC(port, UART_IEC_RE_MSK);
}

static void uart00_enable_ms(struct uart_port *port)
{

	UART_PUT_IES(port, UART_IES_ME_MSK);
}

static void
uart00_rx_chars(struct uart_info *info, struct pt_regs *regs)
{
	struct tty_struct *tty = info->tty;
	unsigned int status, ch, rds, flg, ignored = 0;
	struct uart_port *port = info->port;
	

	status = UART_GET_RSR(port);
	while (UART_RX_DATA(status)) {

		/* 
		 * We need to read rds before reading the 
		 * character from the fifo
		 */
		rds = UART_GET_RDS(port);
		ch = UART_GET_CHAR(port);
		port->icount.rx++;

		if (tty->flip.count >= TTY_FLIPBUF_SIZE)
			goto ignore_char;

		flg = TTY_NORMAL;

		/*
		 * Note that the error handling code is
		 * out of the main execution path
		 */
		if (rds & (UART_RDS_BI_MSK |UART_RDS_FE_MSK|
			   UART_RDS_PE_MSK |UART_RDS_PE_MSK))
			goto handle_error;
		if (uart_handle_sysrq_char(info, ch, regs))
			goto ignore_char;

	error_return:
		*tty->flip.flag_buf_ptr++ = flg;
		*tty->flip.char_buf_ptr++ = ch;
		tty->flip.count++;
	ignore_char:
		status = UART_GET_RSR(port);
	}
out:
	tty_flip_buffer_push(tty);
	return;

handle_error:
	if (rds & UART_RDS_BI_MSK) {
		status &= ~(UART_RDS_FE_MSK | UART_RDS_PE_MSK);
		port->icount.brk++;

#ifdef SUPPORT_SYSRQ
		if (uart_handle_break(info, &uart00_console))
			goto ignore_char;
#endif
	} else if (rds & UART_RDS_PE_MSK)
		port->icount.parity++;
	else if (rds & UART_RDS_PE_MSK)
		port->icount.frame++;
	if (rds & UART_RDS_OE_MSK)
		port->icount.overrun++;

	if (rds & port->ignore_status_mask) {
		if (++ignored > 100)
			goto out;
		goto ignore_char;
	}
	rds &= port->read_status_mask;

	if (rds & UART_RDS_BI_MSK)
		flg = TTY_BREAK;
	else if (rds & UART_RDS_PE_MSK)
		flg = TTY_PARITY;
	else if (rds & UART_RDS_FE_MSK)
		flg = TTY_FRAME;

	if (status & UART_RDS_OE_MSK) {
		/*
		 * CHECK: does overrun affect the current character?
		 * ASSUMPTION: it does not.
		 */
		*tty->flip.flag_buf_ptr++ = flg;
		*tty->flip.char_buf_ptr++ = ch;
		tty->flip.count++;
		if (tty->flip.count >= TTY_FLIPBUF_SIZE)
			goto ignore_char;
		ch = 0;
		flg = TTY_OVERRUN;
	}
#ifdef SUPPORT_SYSRQ
	info->sysrq = 0;
#endif
	goto error_return;
}

static void uart00_tx_chars(struct uart_info *info)
{
	int count;
	struct uart_port *port=info->port;

	if (port->x_char) {
		while((UART_GET_TSR(port)& UART_TSR_TX_LEVEL_MSK)==15);
		UART_PUT_CHAR(port, port->x_char);
		port->icount.tx++;
		port->x_char = 0;
		
		return;
	}
	if (info->xmit.head == info->xmit.tail
	    || info->tty->stopped
	    || info->tty->hw_stopped) {
		uart00_stop_tx(info->port, 0);
		return;
	}

	count = port->fifosize >> 1;
	do {
		while((UART_GET_TSR(port)& UART_TSR_TX_LEVEL_MSK)==15);
		UART_PUT_CHAR(port, info->xmit.buf[info->xmit.tail]);
		info->xmit.tail = (info->xmit.tail + 1) & (UART_XMIT_SIZE - 1);
		port->icount.tx++;
		if (info->xmit.head == info->xmit.tail)
			break;
	} while (--count > 0);

	if (CIRC_CNT(info->xmit.head,
		     info->xmit.tail,
		     UART_XMIT_SIZE) < WAKEUP_CHARS)
		uart_event(info, EVT_WRITE_WAKEUP);

	if (info->xmit.head == info->xmit.tail)
		uart00_stop_tx(info->port, 0);
}

static void uart00_start_tx(struct uart_port *port, u_int nonempty, u_int from_tty)
{
	struct uart_info *info=(struct uart_info*)(port->iobase);

	UART_PUT_IES(port,UART_IES_TIE_MSK );		
	uart00_tx_chars(info);
}

static void uart00_modem_status(struct uart_info *info)
{
	unsigned int status;
	struct uart_icount *icount = &info->port->icount;


	status = UART_GET_MSR(info->port);

	if (!status & (UART_MSR_DCTS_MSK | UART_MSR_DDSR_MSK | 
		       UART_MSR_TERI_MSK | UART_MSR_DDCD_MSK))
		return;

	if (status & UART_MSR_DDCD_MSK) {
		icount->dcd++;
#ifdef CONFIG_HARD_PPS
		if ((info->flags & ASYNC_HARDPPS_CD) &&
		    (status & UART_MSR_DCD_MSK))
			hardpps();
#endif
		if (info->flags & ASYNC_CHECK_CD) {
			if (status & UART_MSR_DCD_MSK)
				wake_up_interruptible(&info->open_wait);
			else if (!((info->flags & ASYNC_CALLOUT_ACTIVE) &&
				   (info->flags & ASYNC_CALLOUT_NOHUP))) {
				if (info->tty)
					tty_hangup(info->tty);
			}
		}
	}

	if (status & UART_MSR_DDSR_MSK)
		icount->dsr++;

	if (status & UART_MSR_DCTS_MSK) {
		icount->cts++;

		if (info->flags & ASYNC_CTS_FLOW) {
			status &= UART_MSR_CTS_MSK;

			if (info->tty->hw_stopped) {
				if (status) {
					info->tty->hw_stopped = 0;
					info->ops->start_tx(info->port, 1, 0);
					uart_event(info, EVT_WRITE_WAKEUP);
				}
			} else {
				if (!status) {
					info->tty->hw_stopped = 1;
					info->ops->stop_tx(info->port, 0);
				}
			}
		}
	}
	wake_up_interruptible(&info->delta_msr_wait);

}

static void uart00_int(int irq, void *dev_id, struct pt_regs *regs)
{
	struct uart_info *info = dev_id;
	unsigned int status, pass_counter = 0;

	status = UART_GET_INT_STATUS(info->port);
	do {

		if (status & UART_ISR_RI_MSK)
			uart00_rx_chars(info, regs);
		if (status & (UART_ISR_TI_MSK | UART_ISR_TII_MSK))
			uart00_tx_chars(info);
		if (status & UART_ISR_MI_MSK)
			uart00_modem_status(info);
		if (pass_counter++ > UART00_ISR_PASS_LIMIT)
			break;

		status = UART_GET_INT_STATUS(info->port);
	} while (status);
}

static u_int uart00_tx_empty(struct uart_port *port)
{
	return UART_GET_TSR(port) & UART_TSR_TX_LEVEL_MSK? 0 : TIOCSER_TEMT;
}

static u_int uart00_get_mctrl(struct uart_port *port)
{
	unsigned int result = 0;
	unsigned int status;

	status = UART_GET_MSR(port);
	if (status & UART_MSR_DCD_MSK)
		result |= TIOCM_CAR;
	if (status & UART_MSR_DSR_MSK)
		result |= TIOCM_DSR;
	if (status & UART_MSR_CTS_MSK)
		result |= TIOCM_CTS;
	if (status & UART_MSR_RI_MSK)
		result |= TIOCM_RI;

	return result;
}

static void uart00_set_mctrl_null(struct uart_port *port, u_int mctrl)
{
}

static void uart00_break_ctl(struct uart_port *port, int break_state)
{
	unsigned int mcr;

	mcr = UART_GET_MCR(port);