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[/] [or1k/] [trunk/] [uclinux/] [uClinux-2.0.x/] [drivers/] [char/] [68328serial.c] - Blame information for rev 1765

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/* 68328serial.c: Serial port driver for 68328 microcontroller
 *
 * Copyright (C) 1995       David S. Miller    <davem@caip.rutgers.edu>
 * Copyright (C) 1998       Kenneth Albanowski <kjahds@kjahds.com>
 * Copyright (C) 1998, 1999 D. Jeff Dionne     <jeff@rt-control.com>
 * Copyright (C) 1999       Vladimir Gurevich  <vgurevic@cisco.com>
 *
 */
 
#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/config.h>
#include <linux/major.h>
#include <linux/string.h>
#include <linux/fcntl.h>
#include <linux/mm.h>
#include <linux/kernel.h>
 
#include <asm/io.h>
#include <asm/irq.h>
#include <asm/system.h>
#include <asm/segment.h>
#include <asm/bitops.h>
#include <asm/delay.h>
 
#include "68328serial.h"
 
 
/* Turn off usage of real serial interrupt code, to "support" Copilot */
#ifdef CONFIG_XCOPILOT_BUGS
#undef USE_INTS
#else
#define USE_INTS
#endif
 
static struct m68k_serial m68k_soft;
 
struct tty_struct m68k_ttys;
struct m68k_serial *m68k_consinfo = 0;
 
#define M68K_CLOCK (16667000) /* FIXME: 16MHz is likely wrong */
 
DECLARE_TASK_QUEUE(tq_serial);
 
struct tty_driver serial_driver, callout_driver;
static int serial_refcount;
 
/* serial subtype definitions */
#define SERIAL_TYPE_NORMAL      1
#define SERIAL_TYPE_CALLOUT     2
 
/* number of characters left in xmit buffer before we ask for more */
#define WAKEUP_CHARS 256
 
/* Debugging... DEBUG_INTR is bad to use when one of the zs
 * lines is your console ;(
 */
#undef SERIAL_DEBUG_INTR
#undef SERIAL_DEBUG_OPEN
#undef SERIAL_DEBUG_FLOW
 
#define RS_ISR_PASS_LIMIT 256
 
#define _INLINE_ inline
 
static void change_speed(struct m68k_serial *info);
 
static struct tty_struct *serial_table[2];
static struct termios *serial_termios[2];
static struct termios *serial_termios_locked[2];
 
#ifndef MIN
#define MIN(a,b)        ((a) < (b) ? (a) : (b))
#endif
 
/*
 * tmp_buf is used as a temporary buffer by serial_write.  We need to
 * lock it in case the memcpy_fromfs blocks while swapping in a page,
 * and some other program tries to do a serial write at the same time.
 * Since the lock will only come under contention when the system is
 * swapping and available memory is low, it makes sense to share one
 * buffer across all the serial ports, since it significantly saves
 * memory if large numbers of serial ports are open.
 */
static unsigned char tmp_buf[SERIAL_XMIT_SIZE]; /* This is cheating */
static struct semaphore tmp_buf_sem = MUTEX;
 
static inline int serial_paranoia_check(struct m68k_serial *info,
                                        dev_t device, const char *routine)
{
#ifdef SERIAL_PARANOIA_CHECK
        static const char *badmagic =
                "Warning: bad magic number for serial struct (%d, %d) in %s\n";
        static const char *badinfo =
                "Warning: null m68k_serial for (%d, %d) in %s\n";
 
        if (!info) {
                printk(badinfo, MAJOR(device), MINOR(device), routine);
                return 1;
        }
        if (info->magic != SERIAL_MAGIC) {
                printk(badmagic, MAJOR(device), MINOR(device), routine);
                return 1;
        }
#endif
        return 0;
}
 
/*
 * This is used to figure out the divisor speeds and the timeouts
 */
static int baud_table[] = {
        0, 50, 75, 110, 134, 150, 200, 300, 600, 1200, 1800, 2400, 4800,
        9600, 19200, 38400, 57600, 115200, 0 };
 
/* Sets or clears DTR/RTS on the requested line */
static inline void m68k_rtsdtr(struct m68k_serial *ss, int set)
{
        if (set) {
                /* set the RTS/CTS line */
        } else {
                /* clear it */
        }
        return;
}
 
/* Utility routines */
static inline int get_baud(struct m68k_serial *ss)
{
        unsigned long result = 115200;
        unsigned short int baud = UBAUD;
        if (GET_FIELD(baud, UBAUD_PRESCALER) == 0x38) result = 38400;
        result >>= GET_FIELD(baud, UBAUD_DIVIDE);
 
        return result;
}
 
/*
 * ------------------------------------------------------------
 * rs_stop() and rs_start()
 *
 * This routines are called before setting or resetting tty->stopped.
 * They enable or disable transmitter interrupts, as necessary.
 * ------------------------------------------------------------
 */
static void rs_stop(struct tty_struct *tty)
{
        struct m68k_serial *info = (struct m68k_serial *)tty->driver_data;
        unsigned long flags;
 
        if (serial_paranoia_check(info, tty->device, "rs_stop"))
                return;
 
        save_flags(flags); cli();
        USTCNT &= ~USTCNT_TXEN;
        restore_flags(flags);
}
 
static void rs_put_char(char ch)
{
        int flags, loops = 0;
 
        save_flags(flags); cli();
 
        while (!(UTX & UTX_TX_AVAIL) && (loops < 1000)) {
                loops++;
                udelay(5);
        }
 
        UTX_TXDATA = ch;
        udelay(5);
        restore_flags(flags);
}
 
static void rs_start(struct tty_struct *tty)
{
        struct m68k_serial *info = (struct m68k_serial *)tty->driver_data;
        unsigned long flags;
 
        if (serial_paranoia_check(info, tty->device, "rs_start"))
                return;
 
        save_flags(flags); cli();
        if (info->xmit_cnt && info->xmit_buf && !(USTCNT & USTCNT_TXEN)) {
#ifdef USE_INTS
                USTCNT |= USTCNT_TXEN | USTCNT_TX_INTR_MASK;
#else
                USTCNT |= USTCNT_TXEN;
#endif
        }
        restore_flags(flags);
}
 
/* Drop into either the boot monitor or kadb upon receiving a break
 * from keyboard/console input.
 */
static void batten_down_hatches(void)
{
        /* Drop into the debugger */
}
 
static _INLINE_ void status_handle(struct m68k_serial *info, unsigned short status)
{
#if 0
        if(status & DCD) {
                if((info->tty->termios->c_cflag & CRTSCTS) &&
                   ((info->curregs[3] & AUTO_ENAB)==0)) {
                        info->curregs[3] |= AUTO_ENAB;
                        info->pendregs[3] |= AUTO_ENAB;
                        write_zsreg(info->m68k_channel, 3, info->curregs[3]);
                }
        } else {
                if((info->curregs[3] & AUTO_ENAB)) {
                        info->curregs[3] &= ~AUTO_ENAB;
                        info->pendregs[3] &= ~AUTO_ENAB;
                        write_zsreg(info->m68k_channel, 3, info->curregs[3]);
                }
        }
#endif
        /* If this is console input and this is a
         * 'break asserted' status change interrupt
         * see if we can drop into the debugger
         */
        if((status & URX_BREAK) && info->break_abort)
                batten_down_hatches();
        return;
}
 
/*
 * This routine is used by the interrupt handler to schedule
 * processing in the software interrupt portion of the driver.
 */
static _INLINE_ void rs_sched_event(struct m68k_serial *info,
                                    int event)
{
        info->event |= 1 << event;
        queue_task_irq_off(&info->tqueue, &tq_serial);
        mark_bh(SERIAL_BH);
}
 
static _INLINE_ void receive_chars(struct m68k_serial *info, struct pt_regs *regs, unsigned short rx)
{
        struct tty_struct *tty = info->tty;
        unsigned char ch;
 
        /*
         * This do { } while() loop will get ALL chars out of Rx FIFO
         */
#ifndef CONFIG_XCOPILOT_BUGS
        do {
#endif  
                ch = GET_FIELD(rx, URX_RXDATA);
 
                if(info->is_cons) {
                        if(URX_BREAK & rx) { /* whee, break received */
                                status_handle(info, rx);
                                return;
                        } else if (ch == 0x10) { /* ^P */
                                show_state();
                                show_free_areas();
                                show_buffers();
                                show_net_buffers();
                                return;
                        } else if (ch == 0x12) { /* ^R */
                                hard_reset_now();
                                return;
                        }
                        /* It is a 'keyboard interrupt' ;-) */
                        wake_up(&keypress_wait);
                }
 
                if(!tty)
                        goto clear_and_exit;
 
                /*
                 * Make sure that we do not overflow the buffer
                 */
                if (tty->flip.count >= TTY_FLIPBUF_SIZE) {
                        queue_task_irq_off(&tty->flip.tqueue, &tq_timer);
                        return;
                }
 
                if(rx & URX_PARITY_ERROR) {
                        *tty->flip.flag_buf_ptr++ = TTY_PARITY;
                        status_handle(info, rx);
                } else if(rx & URX_OVRUN) {
                        *tty->flip.flag_buf_ptr++ = TTY_OVERRUN;
                        status_handle(info, rx);
                } else if(rx & URX_FRAME_ERROR) {
                        *tty->flip.flag_buf_ptr++ = TTY_FRAME;
                        status_handle(info, rx);
                } else {
                        *tty->flip.flag_buf_ptr++ = 0; /* XXX */
                }
                *tty->flip.char_buf_ptr++ = ch;
                tty->flip.count++;
 
#ifndef CONFIG_XCOPILOT_BUGS
        } while((rx = URX) & URX_DATA_READY);
#endif
 
        queue_task_irq_off(&tty->flip.tqueue, &tq_timer);
 
clear_and_exit:
        return;
}
 
static _INLINE_ void transmit_chars(struct m68k_serial *info)
{
        if (info->x_char) {
                /* Send next char */
                UTX_TXDATA = info->x_char;
                info->x_char = 0;
                goto clear_and_return;
        }
 
        if((info->xmit_cnt <= 0) || info->tty->stopped) {
                /* That's peculiar... TX ints off */
                USTCNT &= ~USTCNT_TX_INTR_MASK;
                goto clear_and_return;
        }
 
        /* Send char */
        UTX_TXDATA = info->xmit_buf[info->xmit_tail++];
        info->xmit_tail = info->xmit_tail & (SERIAL_XMIT_SIZE-1);
        info->xmit_cnt--;
 
        if (info->xmit_cnt < WAKEUP_CHARS)
                rs_sched_event(info, RS_EVENT_WRITE_WAKEUP);
 
        if(info->xmit_cnt <= 0) {
                /* All done for now... TX ints off */
                USTCNT &= ~USTCNT_TX_INTR_MASK;
                goto clear_and_return;
        }
 
clear_and_return:
        /* Clear interrupt (should be auto)*/
        return;
}
 
/*
 * This is the serial driver's generic interrupt routine
 */
void rs_interrupt(int irq, void *dev_id, struct pt_regs * regs)
{
        struct m68k_serial * info = &m68k_soft;
        unsigned short rx = URX;
#ifdef USE_INTS
        unsigned short tx = UTX;
 
        if (rx & URX_DATA_READY) receive_chars(info, regs, rx);
        if (tx & UTX_TX_AVAIL)   transmit_chars(info);
#else
        receive_chars(info, regs, rx);
#endif
        return;
}
 
/*
 * This routine is used to handle the "bottom half" processing for the
 * serial driver, known also the "software interrupt" processing.
 * This processing is done at the kernel interrupt level, after the
 * rs_interrupt() has returned, BUT WITH INTERRUPTS TURNED ON.  This
 * is where time-consuming activities which can not be done in the
 * interrupt driver proper are done; the interrupt driver schedules
 * them using rs_sched_event(), and they get done here.
 */
static void do_serial_bh(void)
{
        run_task_queue(&tq_serial);
}
 
static void do_softint(void *private_)
{
        struct m68k_serial      *info = (struct m68k_serial *) private_;
        struct tty_struct       *tty;
 
        tty = info->tty;
        if (!tty)
                return;
 
        if (clear_bit(RS_EVENT_WRITE_WAKEUP, &info->event)) {
                if ((tty->flags & (1 << TTY_DO_WRITE_WAKEUP)) &&
                    tty->ldisc.write_wakeup)
                        (tty->ldisc.write_wakeup)(tty);
                wake_up_interruptible(&tty->write_wait);
        }
}
 
/*
 * This routine is called from the scheduler tqueue when the interrupt
 * routine has signalled that a hangup has occurred.  The path of
 * hangup processing is:
 *
 *      serial interrupt routine -> (scheduler tqueue) ->
 *      do_serial_hangup() -> tty->hangup() -> rs_hangup()
 *
 */
static void do_serial_hangup(void *private_)
{
        struct m68k_serial      *info = (struct m68k_serial *) private_;
        struct tty_struct       *tty;
 
        tty = info->tty;
        if (!tty)
                return;
 
        tty_hangup(tty);
}
 
 
/*
 * This subroutine is called when the RS_TIMER goes off.  It is used
 * by the serial driver to handle ports that do not have an interrupt
 * 68328 does, we had better never get here.
 */
 
static void rs_timer(void)
{
        panic("rs_timer called\n");
        return;
}
 
static int startup(struct m68k_serial * info)
{
        unsigned long flags;
 
        if (info->flags & S_INITIALIZED)
                return 0;
 
        if (!info->xmit_buf) {
                info->xmit_buf = (unsigned char *) get_free_page(GFP_KERNEL);
                if (!info->xmit_buf)
                        return -ENOMEM;
        }
 
        save_flags(flags); cli();
 
        /*
         * Clear the FIFO buffers and disable them
         * (they will be reenabled in change_speed())
         */
 
        USTCNT = USTCNT_UEN;
        info->xmit_fifo_size = 1;
        USTCNT = USTCNT_UEN | USTCNT_RXEN | USTCNT_TXEN;
        (void)URX;
 
        /*
         * Finally, enable sequencing and interrupts
         */
#ifdef USE_INTS
        USTCNT = USTCNT_UEN | USTCNT_RXEN |
                 USTCNT_RX_INTR_MASK | USTCNT_TX_INTR_MASK;
#else
        USTCNT = USTCNT_UEN | USTCNT_RXEN | USTCNT_RX_INTR_MASK;
#endif
 
        if (info->tty)
                clear_bit(TTY_IO_ERROR, &info->tty->flags);
        info->xmit_cnt = info->xmit_head = info->xmit_tail = 0;
 
        /*
         * and set the speed of the serial port
         */
 
        change_speed(info);
 
        info->flags |= S_INITIALIZED;
        restore_flags(flags);
        return 0;
}
 
/*
 * This routine will shutdown a serial port; interrupts are disabled, and
 * DTR is dropped if the hangup on close termio flag is on.
 */
static void shutdown(struct m68k_serial * info)
{
        unsigned long   flags;
 
        USTCNT = 0; /* All off! */
        if (!(info->flags & S_INITIALIZED))
                return;
 
        save_flags(flags); cli(); /* Disable interrupts */
 
        if (info->xmit_buf) {
                free_page((unsigned long) info->xmit_buf);
                info->xmit_buf = 0;
        }
 
        if (info->tty)
                set_bit(TTY_IO_ERROR, &info->tty->flags);
 
        info->flags &= ~S_INITIALIZED;
        restore_flags(flags);
}
 
struct {
        int divisor, prescale;
} hw_baud_table[18] = {
        {0,0}, /* 0 */
        {0,0}, /* 50 */
        {0,0}, /* 75 */
        {0,0}, /* 110 */
        {0,0}, /* 134 */
        {0,0}, /* 150 */
        {0,0}, /* 200 */
        {7,0x26}, /* 300 */
        {6,0x26}, /* 600 */
        {5,0x26}, /* 1200 */
        {0,0}, /* 1800 */
        {4,0x26}, /* 2400 */
        {3,0x26}, /* 4800 */
        {2,0x26}, /* 9600 */
        {1,0x26}, /* 19200 */
        {0,0x26}, /* 38400 */
        {1,0x38}, /* 57600 */
        {0,0x38}, /* 115200 */
};
/* rate = 1036800 / ((65 - prescale) * (1<<divider)) */
 
/*
 * This routine is called to set the UART divisor registers to match
 * the specified baud rate for a serial port.
 */
static void change_speed(struct m68k_serial *info)
{
        unsigned short port;
        unsigned short ustcnt;
        unsigned cflag;
        int     i;
 
        if (!info->tty || !info->tty->termios)
                return;
        cflag = info->tty->termios->c_cflag;
        if (!(port = info->port))
                return;
 
        ustcnt = USTCNT;
        USTCNT = ustcnt & ~USTCNT_TXEN;
 
        i = cflag & CBAUD;
        if (i & CBAUDEX) {
                i = (i & ~CBAUDEX) + B38400;
        }
 
        info->baud = baud_table[i];
        UBAUD = PUT_FIELD(UBAUD_DIVIDE,    hw_baud_table[i].divisor) |
                PUT_FIELD(UBAUD_PRESCALER, hw_baud_table[i].prescale);
 
        ustcnt &= ~(USTCNT_PARITYEN | USTCNT_ODD_EVEN | USTCNT_STOP | USTCNT_8_7);
 
        if ((cflag & CSIZE) == CS8)
                ustcnt |= USTCNT_8_7;
 
        if (cflag & CSTOPB)
                ustcnt |= USTCNT_STOP;
 
        if (cflag & PARENB)
                ustcnt |= USTCNT_PARITYEN;
        if (cflag & PARODD)
                ustcnt |= USTCNT_ODD_EVEN;
 
#ifdef CONFIG_68328_SERIAL_RTS_CTS
        if (cflag & CRTSCTS) {
                UTX &= ~ UTX_NOCTS;
        } else {
                UTX |= UTX_NOCTS;
        }
#endif
 
        ustcnt |= USTCNT_TXEN;
 
        USTCNT = ustcnt;
        return;
}
 
/*
 * Fair output driver allows a process to speak.
 */
static void rs_fair_output(void)
{
        int left;               /* Output no more than that */
        unsigned long flags;
        struct m68k_serial *info = &m68k_soft;
        char c;
 
        if (info == 0) return;
        if (info->xmit_buf == 0) return;
 
        save_flags(flags);  cli();
        left = info->xmit_cnt;
        while (left != 0) {
                c = info->xmit_buf[info->xmit_tail];
                info->xmit_tail = (info->xmit_tail+1) & (SERIAL_XMIT_SIZE-1);
                info->xmit_cnt--;
                restore_flags(flags);
 
                rs_put_char(c);
 
                save_flags(flags);  cli();
                left = MIN(info->xmit_cnt, left-1);
        }
 
        /* Last character is being transmitted now (hopefully). */
        udelay(5);
 
        restore_flags(flags);
        return;
}
 
/*
 * m68k_console_print is registered for printk.
 */
void console_print_68328(const char *p)
{
        char c;
 
        while((c=*(p++)) != 0) {
                if(c == '\n')
                        rs_put_char('\r');
                rs_put_char(c);
        }
 
        /* Comment this if you want to have a strict interrupt-driven output */
        rs_fair_output();
 
        return;
}
 
static void rs_set_ldisc(struct tty_struct *tty)
{
        struct m68k_serial *info = (struct m68k_serial *)tty->driver_data;
 
        if (serial_paranoia_check(info, tty->device, "rs_set_ldisc"))
                return;
 
        info->is_cons = (tty->termios->c_line == N_TTY);
 
        printk("ttyS%d console mode %s\n", info->line, info->is_cons ? "on" : "off");
}
 
static void rs_flush_chars(struct tty_struct *tty)
{
        struct m68k_serial *info = (struct m68k_serial *)tty->driver_data;
        unsigned long flags;
 
        if (serial_paranoia_check(info, tty->device, "rs_flush_chars"))
                return;
#ifndef USE_INTS
        for(;;) {
#endif
        if (info->xmit_cnt <= 0 || tty->stopped || tty->hw_stopped ||
            !info->xmit_buf)
                return;
 
        /* Enable transmitter */
        save_flags(flags); cli();
 
#ifdef USE_INTS
        USTCNT |= USTCNT_TXEN | USTCNT_TX_INTR_MASK;
#else
        USTCNT |= USTCNT_TXEN;
#endif
 
#ifdef USE_INTS
        if (UTX & UTX_TX_AVAIL) {
#else
        if (1) {
#endif
                /* Send char */
                UTX_TXDATA = info->xmit_buf[info->xmit_tail++];
                info->xmit_tail = info->xmit_tail & (SERIAL_XMIT_SIZE-1);
                info->xmit_cnt--;
        }
 
#ifndef USE_INTS
        while (!(UTX & UTX_TX_AVAIL)) udelay(5);
        }
#endif
        restore_flags(flags);
}
 
extern void console_printn(const char * b, int count);
 
static int rs_write(struct tty_struct * tty, int from_user,
                    const unsigned char *buf, int count)
{
        int     c, total = 0;
        struct m68k_serial *info = (struct m68k_serial *)tty->driver_data;
        unsigned long flags;
 
        if (serial_paranoia_check(info, tty->device, "rs_write"))
                return 0;
 
        if (!tty || !info->xmit_buf)
                return 0;
 
        save_flags(flags);
        while (1) {
                cli();
                c = MIN(count, MIN(SERIAL_XMIT_SIZE - info->xmit_cnt - 1,
                                   SERIAL_XMIT_SIZE - info->xmit_head));
                if (c <= 0)
                        break;
 
                if (from_user) {
                        down(&tmp_buf_sem);
                        memcpy_fromfs(tmp_buf, buf, c);
                        c = MIN(c, MIN(SERIAL_XMIT_SIZE - info->xmit_cnt - 1,
                                       SERIAL_XMIT_SIZE - info->xmit_head));
                        memcpy(info->xmit_buf + info->xmit_head, tmp_buf, c);
                        up(&tmp_buf_sem);
                } else
                        memcpy(info->xmit_buf + info->xmit_head, buf, c);
                info->xmit_head = (info->xmit_head + c) & (SERIAL_XMIT_SIZE-1);
                info->xmit_cnt += c;
                restore_flags(flags);
                buf += c;
                count -= c;
                total += c;
        }
 
        if (info->xmit_cnt && !tty->stopped && !tty->hw_stopped) {
                /* Enable transmitter */
                cli();
#ifndef USE_INTS
                while(info->xmit_cnt) {
#endif
 
                USTCNT |= USTCNT_TXEN;
#ifdef USE_INTS
                USTCNT |= USTCNT_TX_INTR_MASK;
#else
                while (!(UTX & UTX_TX_AVAIL)) udelay(5);
#endif
                if (UTX & UTX_TX_AVAIL) {
                        UTX_TXDATA = info->xmit_buf[info->xmit_tail++];
                        info->xmit_tail = info->xmit_tail & (SERIAL_XMIT_SIZE-1);
                        info->xmit_cnt--;
                }
 
#ifndef USE_INTS
                }
#endif
                restore_flags(flags);
        }
        restore_flags(flags);
        return total;
}
 
static int rs_write_room(struct tty_struct *tty)
{
        struct m68k_serial *info = (struct m68k_serial *)tty->driver_data;
        int     ret;
 
        if (serial_paranoia_check(info, tty->device, "rs_write_room"))
                return 0;
        ret = SERIAL_XMIT_SIZE - info->xmit_cnt - 1;
        if (ret < 0)
                ret = 0;
        return ret;
}
 
static int rs_chars_in_buffer(struct tty_struct *tty)
{
        struct m68k_serial *info = (struct m68k_serial *)tty->driver_data;
 
        if (serial_paranoia_check(info, tty->device, "rs_chars_in_buffer"))
                return 0;
        return info->xmit_cnt;
}
 
static void rs_flush_buffer(struct tty_struct *tty)
{
        struct m68k_serial *info = (struct m68k_serial *)tty->driver_data;
 
        if (serial_paranoia_check(info, tty->device, "rs_flush_buffer"))
                return;
        cli();
        info->xmit_cnt = info->xmit_head = info->xmit_tail = 0;
        sti();
        wake_up_interruptible(&tty->write_wait);
        if ((tty->flags & (1 << TTY_DO_WRITE_WAKEUP)) &&
            tty->ldisc.write_wakeup)
                (tty->ldisc.write_wakeup)(tty);
}
 
/*
 * ------------------------------------------------------------
 * rs_throttle()
 *
 * This routine is called by the upper-layer tty layer to signal that
 * incoming characters should be throttled.
 * ------------------------------------------------------------
 */
static void rs_throttle(struct tty_struct * tty)
{
        struct m68k_serial *info = (struct m68k_serial *)tty->driver_data;
 
        if (serial_paranoia_check(info, tty->device, "rs_throttle"))
                return;
 
        if (I_IXOFF(tty))
                info->x_char = STOP_CHAR(tty);
 
        /* Turn off RTS line (do this atomic) */
}
 
static void rs_unthrottle(struct tty_struct * tty)
{
        struct m68k_serial *info = (struct m68k_serial *)tty->driver_data;
 
        if (serial_paranoia_check(info, tty->device, "rs_unthrottle"))
                return;
 
        if (I_IXOFF(tty)) {
                if (info->x_char)
                        info->x_char = 0;
                else
                        info->x_char = START_CHAR(tty);
        }
 
        /* Assert RTS line (do this atomic) */
}
 
/*
 * ------------------------------------------------------------
 * rs_ioctl() and friends
 * ------------------------------------------------------------
 */
 
static int get_serial_info(struct m68k_serial * info,
                           struct serial_struct * retinfo)
{
        struct serial_struct tmp;
 
        if (!retinfo)
                return -EFAULT;
        memset(&tmp, 0, sizeof(tmp));
        tmp.type = info->type;
        tmp.line = info->line;
        tmp.port = info->port;
        tmp.irq = info->irq;
        tmp.flags = info->flags;
        tmp.baud_base = info->baud_base;
        tmp.close_delay = info->close_delay;
        tmp.closing_wait = info->closing_wait;
        tmp.custom_divisor = info->custom_divisor;
        memcpy_tofs(retinfo,&tmp,sizeof(*retinfo));
        return 0;
}
 
static int set_serial_info(struct m68k_serial * info,
                           struct serial_struct * new_info)
{
        struct serial_struct new_serial;
        struct m68k_serial old_info;
        int                     retval = 0;
 
        if (!new_info)
                return -EFAULT;
        memcpy_fromfs(&new_serial,new_info,sizeof(new_serial));
        old_info = *info;
 
        if (!suser()) {
                if ((new_serial.baud_base != info->baud_base) ||
                    (new_serial.type != info->type) ||
                    (new_serial.close_delay != info->close_delay) ||
                    ((new_serial.flags & ~S_USR_MASK) !=
                     (info->flags & ~S_USR_MASK)))
                        return -EPERM;
                info->flags = ((info->flags & ~S_USR_MASK) |
                               (new_serial.flags & S_USR_MASK));
                info->custom_divisor = new_serial.custom_divisor;
                goto check_and_exit;
        }
 
        if (info->count > 1)
                return -EBUSY;
 
        /*
         * OK, past this point, all the error checking has been done.
         * At this point, we start making changes.....
         */
 
        info->baud_base = new_serial.baud_base;
        info->flags = ((info->flags & ~S_FLAGS) |
                        (new_serial.flags & S_FLAGS));
        info->type = new_serial.type;
        info->close_delay = new_serial.close_delay;
        info->closing_wait = new_serial.closing_wait;
 
check_and_exit:
        retval = startup(info);
        return retval;
}
 
/*
 * get_lsr_info - get line status register info
 *
 * Purpose: Let user call ioctl() to get info when the UART physically
 *          is emptied.  On bus types like RS485, the transmitter must
 *          release the bus after transmitting. This must be done when
 *          the transmit shift register is empty, not be done when the
 *          transmit holding register is empty.  This functionality
 *          allows an RS485 driver to be written in user space.
 */
static int get_lsr_info(struct m68k_serial * info, unsigned int *value)
{
        unsigned char status;
 
        cli();
#ifdef CONFIG_68328_SERIAL_RTS_CTS
        status = (UTX & UTX_CTS_STAT) ? 1 : 0;
#else
        status = 0;
#endif
        sti();
        put_user(status,value);
        return 0;
}
 
/*
 * This routine sends a break character out the serial port.
 */
static void send_break( struct m68k_serial * info, int duration)
{
        if (!info->port)
                return;
        current->state = TASK_INTERRUPTIBLE;
        current->timeout = jiffies + duration;
        cli();
#ifdef USE_INTS
        UTX |= UTX_SEND_BREAK;
        schedule();
        UTX &= ~UTX_SEND_BREAK;
#endif
        sti();
}
 
static int rs_ioctl(struct tty_struct *tty, struct file * file,
                    unsigned int cmd, unsigned long arg)
{
        int error;
        struct m68k_serial * info = (struct m68k_serial *)tty->driver_data;
        int retval;
 
        if (serial_paranoia_check(info, tty->device, "rs_ioctl"))
                return -ENODEV;
 
        if ((cmd != TIOCGSERIAL) && (cmd != TIOCSSERIAL) &&
            (cmd != TIOCSERCONFIG) && (cmd != TIOCSERGWILD)  &&
            (cmd != TIOCSERSWILD) && (cmd != TIOCSERGSTRUCT)) {
                if (tty->flags & (1 << TTY_IO_ERROR))
                    return -EIO;
        }
 
        switch (cmd) {
                case TCSBRK:    /* SVID version: non-zero arg --> no break */
                        retval = tty_check_change(tty);
                        if (retval)
                                return retval;
                        tty_wait_until_sent(tty, 0);
                        if (!arg)
                                send_break(info, HZ/4); /* 1/4 second */
                        return 0;
                case TCSBRKP:   /* support for POSIX tcsendbreak() */
                        retval = tty_check_change(tty);
                        if (retval)
                                return retval;
                        tty_wait_until_sent(tty, 0);
                        send_break(info, arg ? arg*(HZ/10) : HZ/4);
                        return 0;
                case TIOCGSOFTCAR:
                        error = verify_area(VERIFY_WRITE, (void *) arg,sizeof(long));
                        if (error)
                                return error;
                        put_fs_long(C_CLOCAL(tty) ? 1 : 0,
                                    (unsigned long *) arg);
                        return 0;
                case TIOCSSOFTCAR:
                        arg = get_fs_long((unsigned long *) arg);
                        tty->termios->c_cflag =
                                ((tty->termios->c_cflag & ~CLOCAL) |
                                 (arg ? CLOCAL : 0));
                        return 0;
                case TIOCGSERIAL:
                        error = verify_area(VERIFY_WRITE, (void *) arg,
                                                sizeof(struct serial_struct));
                        if (error)
                                return error;
                        return get_serial_info(info,
                                               (struct serial_struct *) arg);
                case TIOCSSERIAL:
                        return set_serial_info(info,
                                               (struct serial_struct *) arg);
                case TIOCSERGETLSR: /* Get line status register */
                        error = verify_area(VERIFY_WRITE, (void *) arg,
                                sizeof(unsigned int));
                        if (error)
                                return error;
                        else
                            return get_lsr_info(info, (unsigned int *) arg);
 
                case TIOCSERGSTRUCT:
                        error = verify_area(VERIFY_WRITE, (void *) arg,
                                                sizeof(struct m68k_serial));
                        if (error)
                                return error;
                        memcpy_tofs((struct m68k_serial *) arg,
                                    info, sizeof(struct m68k_serial));
                        return 0;
 
                default:
                        return -ENOIOCTLCMD;
                }
        return 0;
}
 
static void rs_set_termios(struct tty_struct *tty, struct termios *old_termios)
{
        struct m68k_serial *info = (struct m68k_serial *)tty->driver_data;
 
        if (tty->termios->c_cflag == old_termios->c_cflag)
                return;
 
        change_speed(info);
 
        if ((old_termios->c_cflag & CRTSCTS) &&
            !(tty->termios->c_cflag & CRTSCTS)) {
                tty->hw_stopped = 0;
                rs_start(tty);
        }
 
}
 
/*
 * ------------------------------------------------------------
 * rs_close()
 *
 * This routine is called when the serial port gets closed.  First, we
 * wait for the last remaining data to be sent.  Then, we unlink its
 * S structure from the interrupt chain if necessary, and we free
 * that IRQ if nothing is left in the chain.
 * ------------------------------------------------------------
 */
static void rs_close(struct tty_struct *tty, struct file * filp)
{
        struct m68k_serial * info = (struct m68k_serial *)tty->driver_data;
        unsigned long flags;
 
        if (!info || serial_paranoia_check(info, tty->device, "rs_close"))
                return;
 
        save_flags(flags); cli();
 
        if (tty_hung_up_p(filp)) {
                restore_flags(flags);
                return;
        }
 
        if ((tty->count == 1) && (info->count != 1)) {
                /*
                 * Uh, oh.  tty->count is 1, which means that the tty
                 * structure will be freed.  Info->count should always
                 * be one in these conditions.  If it's greater than
                 * one, we've got real problems, since it means the
                 * serial port won't be shutdown.
                 */
                printk("rs_close: bad serial port count; tty->count is 1, "
                       "info->count is %d\n", info->count);
                info->count = 1;
        }
        if (--info->count < 0) {
                printk("rs_close: bad serial port count for ttyS%d: %d\n",
                       info->line, info->count);
                info->count = 0;
        }
        if (info->count) {
                restore_flags(flags);
                return;
        }
        info->flags |= S_CLOSING;
        /*
         * Save the termios structure, since this port may have
         * separate termios for callout and dialin.
         */
        if (info->flags & S_NORMAL_ACTIVE)
                info->normal_termios = *tty->termios;
        if (info->flags & S_CALLOUT_ACTIVE)
                info->callout_termios = *tty->termios;
        /*
         * Now we wait for the transmit buffer to clear; and we notify
         * the line discipline to only process XON/XOFF characters.
         */
        tty->closing = 1;
        if (info->closing_wait != S_CLOSING_WAIT_NONE)
                tty_wait_until_sent(tty, info->closing_wait);
        /*
         * At this point we stop accepting input.  To do this, we
         * disable the receive line status interrupts, and tell the
         * interrupt driver to stop checking the data ready bit in the
         * line status register.
         */
 
        USTCNT &= ~USTCNT_RXEN;
        USTCNT &= ~(USTCNT_RXEN | USTCNT_RX_INTR_MASK);
 
        shutdown(info);
        if (tty->driver.flush_buffer)
                tty->driver.flush_buffer(tty);
        if (tty->ldisc.flush_buffer)
                tty->ldisc.flush_buffer(tty);
        tty->closing = 0;
        info->event = 0;
        info->tty = 0;
        if (tty->ldisc.num != ldiscs[N_TTY].num) {
                if (tty->ldisc.close)
                        (tty->ldisc.close)(tty);
                tty->ldisc = ldiscs[N_TTY];
                tty->termios->c_line = N_TTY;
                if (tty->ldisc.open)
                        (tty->ldisc.open)(tty);
        }
        if (info->blocked_open) {
                if (info->close_delay) {
                        current->state = TASK_INTERRUPTIBLE;
                        current->timeout = jiffies + info->close_delay;
                        schedule();
                }
                wake_up_interruptible(&info->open_wait);
        }
        info->flags &= ~(S_NORMAL_ACTIVE|S_CALLOUT_ACTIVE|
                         S_CLOSING);
        wake_up_interruptible(&info->close_wait);
        restore_flags(flags);
}
 
/*
 * rs_hangup() --- called by tty_hangup() when a hangup is signaled.
 */
void rs_hangup(struct tty_struct *tty)
{
        struct m68k_serial * info = (struct m68k_serial *)tty->driver_data;
 
        if (serial_paranoia_check(info, tty->device, "rs_hangup"))
                return;
 
        rs_flush_buffer(tty);
        shutdown(info);
        info->event = 0;
        info->count = 0;
        info->flags &= ~(S_NORMAL_ACTIVE|S_CALLOUT_ACTIVE);
        info->tty = 0;
        wake_up_interruptible(&info->open_wait);
}
 
/*
 * ------------------------------------------------------------
 * rs_open() and friends
 * ------------------------------------------------------------
 */
static int block_til_ready(struct tty_struct *tty, struct file * filp,
                           struct m68k_serial *info)
{
        struct wait_queue wait = { current, NULL };
        int             retval;
        int             do_clocal = 0;
 
        /*
         * If the device is in the middle of being closed, then block
         * until it's done, and then try again.
         */
        if (info->flags & S_CLOSING) {
                interruptible_sleep_on(&info->close_wait);
#ifdef SERIAL_DO_RESTART
                if (info->flags & S_HUP_NOTIFY)
                        return -EAGAIN;
                else
                        return -ERESTARTSYS;
#else
                return -EAGAIN;
#endif
        }
 
        /*
         * If this is a callout device, then just make sure the normal
         * device isn't being used.
         */
        if (tty->driver.subtype == SERIAL_TYPE_CALLOUT) {
                if (info->flags & S_NORMAL_ACTIVE)
                        return -EBUSY;
                if ((info->flags & S_CALLOUT_ACTIVE) &&
                    (info->flags & S_SESSION_LOCKOUT) &&
                    (info->session != current->session))
                    return -EBUSY;
                if ((info->flags & S_CALLOUT_ACTIVE) &&
                    (info->flags & S_PGRP_LOCKOUT) &&
                    (info->pgrp != current->pgrp))
                    return -EBUSY;
                info->flags |= S_CALLOUT_ACTIVE;
                return 0;
        }
 
        /*
         * If non-blocking mode is set, or the port is not enabled,
         * then make the check up front and then exit.
         */
        if ((filp->f_flags & O_NONBLOCK) ||
            (tty->flags & (1 << TTY_IO_ERROR))) {
                if (info->flags & S_CALLOUT_ACTIVE)
                        return -EBUSY;
                info->flags |= S_NORMAL_ACTIVE;
                return 0;
        }
 
        if (info->flags & S_CALLOUT_ACTIVE) {
                if (info->normal_termios.c_cflag & CLOCAL)
                        do_clocal = 1;
        } else {
                if (tty->termios->c_cflag & CLOCAL)
                        do_clocal = 1;
        }
 
        /*
         * Block waiting for the carrier detect and the line to become
         * free (i.e., not in use by the callout).  While we are in
         * this loop, info->count is dropped by one, so that
         * rs_close() knows when to free things.  We restore it upon
         * exit, either normal or abnormal.
         */
        retval = 0;
        add_wait_queue(&info->open_wait, &wait);
 
        info->count--;
        info->blocked_open++;
        while (1) {
                cli();
                if (!(info->flags & S_CALLOUT_ACTIVE))
                        m68k_rtsdtr(info, 1);
                sti();
                current->state = TASK_INTERRUPTIBLE;
                if (tty_hung_up_p(filp) ||
                    !(info->flags & S_INITIALIZED)) {
#ifdef SERIAL_DO_RESTART
                        if (info->flags & S_HUP_NOTIFY)
                                retval = -EAGAIN;
                        else
                                retval = -ERESTARTSYS;
#else
                        retval = -EAGAIN;
#endif
                        break;
                }
                if (!(info->flags & S_CALLOUT_ACTIVE) &&
                    !(info->flags & S_CLOSING) && do_clocal)
                        break;
                if (current->signal & ~current->blocked) {
                        retval = -ERESTARTSYS;
                        break;
                }
                schedule();
        }
        current->state = TASK_RUNNING;
        remove_wait_queue(&info->open_wait, &wait);
        if (!tty_hung_up_p(filp))
                info->count++;
        info->blocked_open--;
 
        if (retval)
                return retval;
        info->flags |= S_NORMAL_ACTIVE;
        return 0;
}
 
/*
 * This routine is called whenever a serial port is opened.  It
 * enables interrupts for a serial port, linking in its S structure into
 * the IRQ chain.   It also performs the serial-specific
 * initialization for the tty structure.
 */
int rs_open(struct tty_struct *tty, struct file * filp)
{
        struct m68k_serial      *info;
        int                     retval, line;
 
        line = MINOR(tty->device) - tty->driver.minor_start;
 
        if (line != 0) /* we have exactly one */
                return -ENODEV;
 
        info = &m68k_soft;
 
        if (serial_paranoia_check(info, tty->device, "rs_open"))
                return -ENODEV;
 
        info->count++;
        tty->driver_data = info;
        info->tty = tty;
 
        /*
         * Start up serial port
         */
        retval = startup(info);
        if (retval)
                return retval;
 
        retval = block_til_ready(tty, filp, info);
        if (retval) {
                return retval;
        }
 
        if ((info->count == 1) && (info->flags & S_SPLIT_TERMIOS)) {
                if (tty->driver.subtype == SERIAL_TYPE_NORMAL)
                        *tty->termios = info->normal_termios;
                else
                        *tty->termios = info->callout_termios;
                change_speed(info);
        }
 
        info->session = current->session;
        info->pgrp = current->pgrp;
 
        return 0;
}
 
/* Finally, routines used to initialize the serial driver. */
 
static void show_serial_version(void)
{
        printk("MC68328 serial driver version 1.00\n");
}
 
extern void register_console(void (*proc)(const char *));
 
volatile int test_done;
 
/* rs_init inits the driver */
int rs68328_init(void)
{
        int flags;
        struct m68k_serial *info;
 
        /* Setup base handler, and timer table. */
        init_bh(SERIAL_BH, do_serial_bh);
        timer_table[RS_TIMER].fn = rs_timer;
        timer_table[RS_TIMER].expires = 0;
 
        show_serial_version();
 
        /* Initialize the tty_driver structure */
        /* SPARC: Not all of this is exactly right for us. */
 
        memset(&serial_driver, 0, sizeof(struct tty_driver));
        serial_driver.magic = TTY_DRIVER_MAGIC;
        serial_driver.name = "ttyS";
        serial_driver.major = TTY_MAJOR;
        serial_driver.minor_start = 64;
        serial_driver.num = 1;
        serial_driver.type = TTY_DRIVER_TYPE_SERIAL;
        serial_driver.subtype = SERIAL_TYPE_NORMAL;
        serial_driver.init_termios = tty_std_termios;
 
 
        serial_driver.init_termios.c_cflag =
#if   defined(CONFIG_PILOT)
                B9600 | CS8 | CREAD | HUPCL | CLOCAL;
#elif defined(CONFIG_UCSIMM)
                B9600 | CS8 | CREAD | HUPCL | CLOCAL;
#elif defined(CONFIG_M68EZ328ADS)
                B115200 | CS8 | CREAD | HUPCL | CLOCAL;
#elif defined(CONFIG_ALMA_ANS)
                B115200 | CS8 | CREAD | HUPCL | CLOCAL;
#else 
#error  Please, define the default console settings for your board
#endif
 
        serial_driver.flags = TTY_DRIVER_REAL_RAW;
        serial_driver.refcount = &serial_refcount;
        serial_driver.table = serial_table;
        serial_driver.termios = serial_termios;
        serial_driver.termios_locked = serial_termios_locked;
 
        serial_driver.open = rs_open;
        serial_driver.close = rs_close;
        serial_driver.write = rs_write;
        serial_driver.flush_chars = rs_flush_chars;
        serial_driver.write_room = rs_write_room;
        serial_driver.chars_in_buffer = rs_chars_in_buffer;
        serial_driver.flush_buffer = rs_flush_buffer;
        serial_driver.ioctl = rs_ioctl;
        serial_driver.throttle = rs_throttle;
        serial_driver.unthrottle = rs_unthrottle;
        serial_driver.set_termios = rs_set_termios;
        serial_driver.stop = rs_stop;
        serial_driver.start = rs_start;
        serial_driver.hangup = rs_hangup;
        serial_driver.set_ldisc = rs_set_ldisc;
 
        /*
         * The callout device is just like normal device except for
         * major number and the subtype code.
         */
        callout_driver = serial_driver;
        callout_driver.name = "cua";
        callout_driver.major = TTYAUX_MAJOR;
        callout_driver.subtype = SERIAL_TYPE_CALLOUT;
 
        if (tty_register_driver(&serial_driver))
                panic("Couldn't register serial driver\n");
        if (tty_register_driver(&callout_driver))
                panic("Couldn't register callout driver\n");
 
        save_flags(flags); cli();
 
        info = &m68k_soft;
        info->magic = SERIAL_MAGIC;
        info->port = 0xfffff900;
        info->tty = 0;
        info->irq = 0x40;
        info->custom_divisor = 16;
        info->close_delay = 50;
        info->closing_wait = 3000;
        info->x_char = 0;
        info->event = 0;
        info->count = 0;
        info->blocked_open = 0;
        info->tqueue.routine = do_softint;
        info->tqueue.data = info;
        info->tqueue_hangup.routine = do_serial_hangup;
        info->tqueue_hangup.data = info;
        info->callout_termios =callout_driver.init_termios;
        info->normal_termios = serial_driver.init_termios;
        info->open_wait = 0;
        info->close_wait = 0;
        info->line = 0;
        info->is_cons = 1; /* Means shortcuts work */
 
        printk("%s%d at 0x%08x (irq = %d)", serial_driver.name, info->line,
               info->port, info->irq);
                printk(" is a builtin MC68328 UART\n");
 
        if (request_irq(IRQ_MACHSPEC | UART_IRQ_NUM,
                        rs_interrupt,
                        IRQ_FLG_STD,
                        "M68328_UART", NULL))
                panic("Unable to attach 68328 serial interrupt\n");
        restore_flags(flags);
        return 0;
}
 
/*
 * register_serial and unregister_serial allows for serial ports to be
 * configured at run-time, to support PCMCIA modems.
 */
/* SPARC: Unused at this time, just here to make things link. */
int register_serial(struct serial_struct *req)
{
        return -1;
}
 
void unregister_serial(int line)
{
        return;
}
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[/] [or1k/] [trunk/] [uclinux/] [uClinux-2.0.x/] [drivers/] [char/] [68328serial.c] - Blame information for rev 1765

Line No.	Rev	Author	Line
1	199	simons	`/* 68328serial.c: Serial port driver for 68328 microcontroller`
2			`*`
3			`* Copyright (C) 1995 David S. Miller <davem@caip.rutgers.edu>`
4			`* Copyright (C) 1998 Kenneth Albanowski <kjahds@kjahds.com>`
5			`* Copyright (C) 1998, 1999 D. Jeff Dionne <jeff@rt-control.com>`
6			`* Copyright (C) 1999 Vladimir Gurevich <vgurevic@cisco.com>`
7			`*`
8			`*/`
9
10			`#include <linux/errno.h>`
11			`#include <linux/signal.h>`
12			`#include <linux/sched.h>`
13			`#include <linux/timer.h>`
14			`#include <linux/interrupt.h>`
15			`#include <linux/tty.h>`
16			`#include <linux/tty_flip.h>`
17			`#include <linux/config.h>`
18			`#include <linux/major.h>`
19			`#include <linux/string.h>`
20			`#include <linux/fcntl.h>`
21			`#include <linux/mm.h>`
22			`#include <linux/kernel.h>`
23
24			`#include <asm/io.h>`
25			`#include <asm/irq.h>`
26			`#include <asm/system.h>`
27			`#include <asm/segment.h>`
28			`#include <asm/bitops.h>`
29			`#include <asm/delay.h>`
30
31			`#include "68328serial.h"`
32
33
34			`/* Turn off usage of real serial interrupt code, to "support" Copilot */`
35			`#ifdef CONFIG_XCOPILOT_BUGS`
36			`#undef USE_INTS`
37			`#else`
38			`#define USE_INTS`
39			`#endif`
40