sh-sci.c

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/* $Id: sh-sci.c,v 1.40 2000/04/15 06:57:29 gniibe Exp $
 *
 *  linux/drivers/char/sh-sci.c
 *
 *  SuperH on-chip serial module support.  (SCI with no FIFO / with FIFO)
 *  Copyright (C) 1999, 2000  Niibe Yutaka
 *  Copyright (C) 2000  Sugioka Toshinobu
 *  Modified to support multiple serial ports. Stuart Menefy (May 2000).
 *
 * TTY code is based on sx.c (Specialix SX driver) by:
 *
 *   (C) 1998 [e-mail]
 *
 */

#include <linux/config.h>
#include <linux/module.h>
#include <linux/errno.h>
#include <linux/signal.h>
#include <linux/sched.h>
#include <linux/timer.h>
#include <linux/interrupt.h>
#include <linux/tty.h>
#include <linux/tty_flip.h>
#include <linux/serial.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/malloc.h>
#include <linux/init.h>
#include <linux/delay.h>
#ifdef CONFIG_SERIAL_CONSOLE
#include <linux/console.h>
#endif

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

#include <linux/generic_serial.h>

#ifdef CONFIG_DEBUG_KERNEL_WITH_GDB_STUB
#include <asm/sh_bios.h>
#endif

#include "sh-sci.h"

#ifdef CONFIG_SERIAL_CONSOLE
static struct console sercons;
static struct sci_port* sercons_port=0;
static int sercons_baud;
#endif

/* Function prototypes */
static void sci_init_pins_sci(struct sci_port* port, unsigned int cflag);
#ifndef SCI_ONLY
static void sci_init_pins_scif(struct sci_port* port, unsigned int cflag);
#if defined(__sh3__)
static void sci_init_pins_irda(struct sci_port* port, unsigned int cflag);
#endif
#endif
static void sci_disable_tx_interrupts(void *ptr);
static void sci_enable_tx_interrupts(void *ptr);
static void sci_disable_rx_interrupts(void *ptr);
static void sci_enable_rx_interrupts(void *ptr);
static int  sci_get_CD(void *ptr);
static void sci_shutdown_port(void *ptr);
static int sci_set_real_termios(void *ptr);
static void sci_hungup(void *ptr);
static void sci_close(void *ptr);
static int sci_chars_in_buffer(void *ptr);
static int sci_init_drivers(void);

static struct tty_driver sci_driver, sci_callout_driver;

static struct sci_port sci_ports[SCI_NPORTS] = SCI_INIT;
static struct tty_struct *sci_table[SCI_NPORTS] = { NULL, };
static struct termios *sci_termios[SCI_NPORTS];
static struct termios *sci_termios_locked[SCI_NPORTS];

int sci_refcount;
int sci_debug = 0;

#ifdef MODULE
MODULE_PARM(sci_debug, "i");
#endif

#define dprintk(x...) do { if (sci_debug) printk(x); } while(0)

static void put_char(struct sci_port *port, char c)
{
	unsigned long flags;
	unsigned short status;

	save_and_cli(flags);

	do
		status = sci_in(port, SCxSR);
	while (!(status & SCxSR_TDxE(port)));
  
	sci_out(port, SCxTDR, c);
	sci_in(port, SCxSR);            /* Dummy read */
	sci_out(port, SCxSR, SCxSR_TDxE_CLEAR(port));

	restore_flags(flags);
}

#ifdef CONFIG_DEBUG_KERNEL_WITH_GDB_STUB

static void handle_error(struct sci_port *port)
{				/* Clear error flags */
	sci_out(port, SCxSR, SCxSR_ERROR_CLEAR(port));
}

static int get_char(struct sci_port *port)
{
	unsigned long flags;
	unsigned short status;
	int c;

	save_and_cli(flags);
        do {
		status = sci_in(port, SCxSR);
		if (status & SCxSR_ERRORS(port)) {
			handle_error(port);
			continue;
		}
	} while (!(status & SCxSR_RDxF(port)));
	c = sci_in(port, SCxRDR);
	sci_in(port, SCxSR);            /* Dummy read */
	sci_out(port, SCxSR, SCxSR_RDxF_CLEAR(port));
	restore_flags(flags);

	return c;
}

/* Taken from sh-stub.c of GDB 4.18 */
static const char hexchars[] = "0123456789abcdef";

static __inline__ char highhex(int  x)
{
	return hexchars[(x >> 4) & 0xf];
}

static __inline__ char lowhex(int  x)
{
	return hexchars[x & 0xf];
}

#endif

/*
 * Send the packet in buffer.  The host gets one chance to read it.
 * This routine does not wait for a positive acknowledge.
 */

static void put_string(struct sci_port *port,
				  const char *buffer, int count)
{
	int i;
	const unsigned char *p = buffer;
#ifdef CONFIG_DEBUG_KERNEL_WITH_GDB_STUB
	int checksum;

    	/* This call only does a trap the first time it is
	 * called, and so is safe to do here unconditionally
	 */
	if (sh_bios_in_gdb_mode()) {
	    /*  $<packet info>#<checksum>. */
	    do {
		unsigned char c;
		put_char(port, '$');
		put_char(port, 'O'); /* 'O'utput to console */
		checksum = 'O';

		for (i=0; i<count; i++) { /* Don't use run length encoding */
			int h, l;

			c = *p++;
			h = highhex(c);
			l = lowhex(c);
			put_char(port, h);
			put_char(port, l);
			checksum += h + l;
		}
		put_char(port, '#');
		put_char(port, highhex(checksum));
		put_char(port, lowhex(checksum));
	    } while  (get_char(port) != '+');
	} else
#endif
	for (i=0; i<count; i++) {
		if (*p == 10)
			put_char(port, '\r');
		put_char(port, *p++);
	}
}



static struct real_driver sci_real_driver = {
	sci_disable_tx_interrupts,
	sci_enable_tx_interrupts,
	sci_disable_rx_interrupts,
	sci_enable_rx_interrupts,
	sci_get_CD,
	sci_shutdown_port,
	sci_set_real_termios,
	sci_chars_in_buffer,
	sci_close,
	sci_hungup,
	NULL
};

#if defined(SCI_ONLY) || defined(SCI_AND_SCIF)
static void sci_init_pins_sci(struct sci_port* port, unsigned int cflag)
{
}
#endif

#if defined(SCIF_ONLY) || defined(SCI_AND_SCIF)
#if defined(__sh3__)
/* For SH7707, SH7709, SH7709A, SH7729 */
static void sci_init_pins_scif(struct sci_port* port, unsigned int cflag)
{
	unsigned int fcr_val = 0;

	{
		unsigned short data;

		/* We need to set SCPCR to enable RTS/CTS */
		data = ctrl_inw(SCPCR);
		/* Clear out SCP7MD1,0, SCP6MD1,0, SCP4MD1,0*/
		ctrl_outw(data&0x0fcf, SCPCR);
	}
	if (cflag & CRTSCTS)
		fcr_val |= SCFCR_MCE;
	else {
		unsigned short data;

		/* We need to set SCPCR to enable RTS/CTS */
		data = ctrl_inw(SCPCR);
		/* Clear out SCP7MD1,0, SCP4MD1,0,
		   Set SCP6MD1,0 = {01} (output)  */
		ctrl_outw((data&0x0fcf)|0x1000, SCPCR);

		data = ctrl_inb(SCPDR);
		/* Set /RTS2 (bit6) = 0 */
		ctrl_outb(data&0xbf, SCPDR);
	}
	sci_out(port, SCFCR, fcr_val);
}

static void sci_init_pins_irda(struct sci_port* port, unsigned int cflag)
{
	unsigned int fcr_val = 0;

	if (cflag & CRTSCTS)
		fcr_val |= SCFCR_MCE;

	sci_out(port, SCFCR, fcr_val);
}

#else

/* For SH7750 */
static void sci_init_pins_scif(struct sci_port* port, unsigned int cflag)
{
	unsigned int fcr_val = 0;

	if (cflag & CRTSCTS) {
		fcr_val |= SCFCR_MCE;
	} else {
		ctrl_outw(0x0080, SCSPTR2); /* Set RTS = 1 */
	}
	sci_out(port, SCFCR, fcr_val);
}

#endif
#endif /* SCIF_ONLY || SCI_AND_SCIF */

static void sci_setsignals(struct sci_port *port, int dtr, int rts)
{
	/* This routine is used for seting signals of: DTR, DCD, CTS/RTS */
	/* We use SCIF's hardware for CTS/RTS, so don't need any for that. */
	/* If you have signals for DTR and DCD, please implement here. */
	;
}

static int sci_getsignals(struct sci_port *port)
{
	/* This routine is used for geting signals of: DTR, DCD, DSR, RI,
	   and CTS/RTS */

	return TIOCM_DTR|TIOCM_RTS|TIOCM_DSR;
/*
	(((o_stat & OP_DTR)?TIOCM_DTR:0) |
	 ((o_stat & OP_RTS)?TIOCM_RTS:0) |
	 ((i_stat & IP_CTS)?TIOCM_CTS:0) |
	 ((i_stat & IP_DCD)?TIOCM_CAR:0) |
	 ((i_stat & IP_DSR)?TIOCM_DSR:0) |
	 ((i_stat & IP_RI) ?TIOCM_RNG:0)
*/
}

static void sci_set_baud(struct sci_port *port, int baud)
{
	int t;

	switch (baud) {
	case 0:
		t = -1;
		break;
	case 2400:
		t = BPS_2400;
		break;
	case 4800:
		t = BPS_4800;
		break;
	case 9600:
		t = BPS_9600;
		break;
	case 19200:
		t = BPS_19200;
		break;
	case 38400:
		t = BPS_38400;
		break;
	case 57600:
		t = BPS_57600;
		break;
	default:
		printk(KERN_INFO "sci: unsupported baud rate: %d, using 115200 instead.\n", baud);
	case 115200:
		t = BPS_115200;
		break;
	}

	if (t > 0) {
		sci_setsignals (port, 1, -1);
		if(t >= 256) {
			sci_out(port, SCSMR, (sci_in(port, SCSMR) & ~3) | 1);
			t >>= 2;
		} else {
			sci_out(port, SCSMR, sci_in(port, SCSMR) & ~3);
		}
		sci_out(port, SCBRR, t);
		udelay((1000000+(baud-1)) / baud); /* Wait one bit interval */
	} else {
		sci_setsignals (port, 0, -1);
	}
}

static void sci_set_termios_cflag(struct sci_port *port, int cflag, int baud)
{
	unsigned int status;
	unsigned int smr_val;

	do
		status = sci_in(port, SCxSR);
	while (!(status & SCxSR_TEND(port)));

	sci_out(port, SCSCR, 0x00);	/* TE=0, RE=0, CKE1=0 */

	if (port->type == PORT_SCIF) {
		sci_out(port, SCFCR, SCFCR_RFRST | SCFCR_TFRST);
	}

	smr_val = sci_in(port, SCSMR) & 3;
	if ((cflag & CSIZE) == CS7)
		smr_val |= 0x40;
	if (cflag & PARENB)
		smr_val |= 0x20;
	if (cflag & PARODD)
		smr_val |= 0x10;
	if (cflag & CSTOPB)
		smr_val |= 0x08;
	sci_out(port, SCSMR, smr_val);
	sci_set_baud(port, baud);

	port->init_pins(port, cflag);
	sci_out(port, SCSCR, SCSCR_INIT(port));
}

static int sci_set_real_termios(void *ptr)
{
	struct sci_port *port = ptr;

	if (port->old_cflag != port->gs.tty->termios->c_cflag) {
		port->old_cflag = port->gs.tty->termios->c_cflag;
		sci_set_termios_cflag(port, port->old_cflag, port->gs.baud);
		sci_enable_rx_interrupts(port);
	}

	/* Tell line discipline whether we will do input cooking */
	if (I_OTHER(port->gs.tty))
		clear_bit(TTY_HW_COOK_IN, &port->gs.tty->flags);
	else
		set_bit(TTY_HW_COOK_IN, &port->gs.tty->flags);

/* Tell line discipline whether we will do output cooking.
 * If OPOST is set and no other output flags are set then we can do output
 * processing.  Even if only *one* other flag in the O_OTHER group is set
 * we do cooking in software.
 */
	if (O_OPOST(port->gs.tty) && !O_OTHER(port->gs.tty))
		set_bit(TTY_HW_COOK_OUT, &port->gs.tty->flags);
	else
		clear_bit(TTY_HW_COOK_OUT, &port->gs.tty->flags);

	return 0;
}

/* ********************************************************************** *
 *                   the interrupt related routines                       *
 * ********************************************************************** */

/*
 * This routine is used by the interrupt handler to schedule
 * processing in the software interrupt portion of the driver.
 */