Root/drivers/tty/serial/68328serial.c

1/* 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@uclinux.org>
6 * Copyright (C) 1999 Vladimir Gurevich <vgurevic@cisco.com>
7 * Copyright (C) 2002-2003 David McCullough <davidm@snapgear.com>
8 * Copyright (C) 2002 Greg Ungerer <gerg@snapgear.com>
9 *
10 * VZ Support/Fixes Evan Stawnyczy <e@lineo.ca>
11 * Multiple UART support Daniel Potts <danielp@cse.unsw.edu.au>
12 * Power management support Daniel Potts <danielp@cse.unsw.edu.au>
13 * VZ Second Serial Port enable Phil Wilshire
14 * 2.4/2.5 port David McCullough
15 */
16
17#include <asm/dbg.h>
18#include <linux/module.h>
19#include <linux/errno.h>
20#include <linux/serial.h>
21#include <linux/signal.h>
22#include <linux/sched.h>
23#include <linux/timer.h>
24#include <linux/interrupt.h>
25#include <linux/tty.h>
26#include <linux/tty_flip.h>
27#include <linux/major.h>
28#include <linux/string.h>
29#include <linux/fcntl.h>
30#include <linux/mm.h>
31#include <linux/kernel.h>
32#include <linux/console.h>
33#include <linux/reboot.h>
34#include <linux/keyboard.h>
35#include <linux/init.h>
36#include <linux/pm.h>
37#include <linux/bitops.h>
38#include <linux/delay.h>
39#include <linux/gfp.h>
40
41#include <asm/io.h>
42#include <asm/irq.h>
43#include <asm/delay.h>
44#include <asm/uaccess.h>
45
46/* (es) */
47/* note: perhaps we can murge these files, so that you can just
48 * define 1 of them, and they can sort that out for themselves
49 */
50#if defined(CONFIG_M68EZ328)
51#include <asm/MC68EZ328.h>
52#else
53#if defined(CONFIG_M68VZ328)
54#include <asm/MC68VZ328.h>
55#else
56#include <asm/MC68328.h>
57#endif /* CONFIG_M68VZ328 */
58#endif /* CONFIG_M68EZ328 */
59
60/* Turn off usage of real serial interrupt code, to "support" Copilot */
61#ifdef CONFIG_XCOPILOT_BUGS
62#undef USE_INTS
63#else
64#define USE_INTS
65#endif
66
67/*
68 * I believe this is the optimal setting that reduces the number of interrupts.
69 * At high speeds the output might become a little "bursted" (use USTCNT_TXHE
70 * if that bothers you), but in most cases it will not, since we try to
71 * transmit characters every time rs_interrupt is called. Thus, quite often
72 * you'll see that a receive interrupt occures before the transmit one.
73 * -- Vladimir Gurevich
74 */
75#define USTCNT_TX_INTR_MASK (USTCNT_TXEE)
76
77/*
78 * 68328 and 68EZ328 UARTS are a little bit different. EZ328 has special
79 * "Old data interrupt" which occures whenever the data stay in the FIFO
80 * longer than 30 bits time. This allows us to use FIFO without compromising
81 * latency. '328 does not have this feature and without the real 328-based
82 * board I would assume that RXRE is the safest setting.
83 *
84 * For EZ328 I use RXHE (Half empty) interrupt to reduce the number of
85 * interrupts. RXFE (receive queue full) causes the system to lose data
86 * at least at 115200 baud
87 *
88 * If your board is busy doing other stuff, you might consider to use
89 * RXRE (data ready intrrupt) instead.
90 *
91 * The other option is to make these INTR masks run-time configurable, so
92 * that people can dynamically adapt them according to the current usage.
93 * -- Vladimir Gurevich
94 */
95
96/* (es) */
97#if defined(CONFIG_M68EZ328) || defined(CONFIG_M68VZ328)
98#define USTCNT_RX_INTR_MASK (USTCNT_RXHE | USTCNT_ODEN)
99#elif defined(CONFIG_M68328)
100#define USTCNT_RX_INTR_MASK (USTCNT_RXRE)
101#else
102#error Please, define the Rx interrupt events for your CPU
103#endif
104/* (/es) */
105
106/*
107 * This is our internal structure for each serial port's state.
108 */
109struct m68k_serial {
110    struct tty_port tport;
111    char is_cons; /* Is this our console. */
112    int magic;
113    int baud_base;
114    int port;
115    int irq;
116    int type; /* UART type */
117    int custom_divisor;
118    int x_char; /* xon/xoff character */
119    int line;
120    unsigned char *xmit_buf;
121    int xmit_head;
122    int xmit_tail;
123    int xmit_cnt;
124};
125
126#define SERIAL_MAGIC 0x5301
127
128/*
129 * Define the number of ports supported and their irqs.
130 */
131#define NR_PORTS 1
132
133static struct m68k_serial m68k_soft[NR_PORTS];
134
135static unsigned int uart_irqs[NR_PORTS] = { UART_IRQ_NUM };
136
137/* multiple ports are contiguous in memory */
138m68328_uart *uart_addr = (m68328_uart *)USTCNT_ADDR;
139
140struct tty_driver *serial_driver;
141
142static void change_speed(struct m68k_serial *info, struct tty_struct *tty);
143
144/*
145 * Setup for console. Argument comes from the boot command line.
146 */
147
148/* note: this is messy, but it works, again, perhaps defined somewhere else?*/
149#ifdef CONFIG_M68VZ328
150#define CONSOLE_BAUD_RATE 19200
151#define DEFAULT_CBAUD B19200
152#endif
153
154
155#ifndef CONSOLE_BAUD_RATE
156#define CONSOLE_BAUD_RATE 9600
157#define DEFAULT_CBAUD B9600
158#endif
159
160
161static int m68328_console_initted = 0;
162static int m68328_console_baud = CONSOLE_BAUD_RATE;
163static int m68328_console_cbaud = DEFAULT_CBAUD;
164
165
166static inline int serial_paranoia_check(struct m68k_serial *info,
167                    char *name, const char *routine)
168{
169#ifdef SERIAL_PARANOIA_CHECK
170    static const char *badmagic =
171        "Warning: bad magic number for serial struct %s in %s\n";
172    static const char *badinfo =
173        "Warning: null m68k_serial for %s in %s\n";
174
175    if (!info) {
176        printk(badinfo, name, routine);
177        return 1;
178    }
179    if (info->magic != SERIAL_MAGIC) {
180        printk(badmagic, name, routine);
181        return 1;
182    }
183#endif
184    return 0;
185}
186
187/*
188 * This is used to figure out the divisor speeds and the timeouts
189 */
190static int baud_table[] = {
191    0, 50, 75, 110, 134, 150, 200, 300, 600, 1200, 1800, 2400, 4800,
192    9600, 19200, 38400, 57600, 115200, 0 };
193
194/* Utility routines */
195static inline int get_baud(struct m68k_serial *ss)
196{
197    unsigned long result = 115200;
198    unsigned short int baud = uart_addr[ss->line].ubaud;
199    if (GET_FIELD(baud, UBAUD_PRESCALER) == 0x38) result = 38400;
200    result >>= GET_FIELD(baud, UBAUD_DIVIDE);
201
202    return result;
203}
204
205/*
206 * ------------------------------------------------------------
207 * rs_stop() and rs_start()
208 *
209 * This routines are called before setting or resetting tty->stopped.
210 * They enable or disable transmitter interrupts, as necessary.
211 * ------------------------------------------------------------
212 */
213static void rs_stop(struct tty_struct *tty)
214{
215    struct m68k_serial *info = (struct m68k_serial *)tty->driver_data;
216    m68328_uart *uart = &uart_addr[info->line];
217    unsigned long flags;
218
219    if (serial_paranoia_check(info, tty->name, "rs_stop"))
220        return;
221    
222    local_irq_save(flags);
223    uart->ustcnt &= ~USTCNT_TXEN;
224    local_irq_restore(flags);
225}
226
227static int rs_put_char(char ch)
228{
229    unsigned long flags;
230    int loops = 0;
231
232        local_irq_save(flags);
233
234    while (!(UTX & UTX_TX_AVAIL) && (loops < 1000)) {
235            loops++;
236            udelay(5);
237        }
238
239    UTX_TXDATA = ch;
240        udelay(5);
241        local_irq_restore(flags);
242        return 1;
243}
244
245static void rs_start(struct tty_struct *tty)
246{
247    struct m68k_serial *info = (struct m68k_serial *)tty->driver_data;
248    m68328_uart *uart = &uart_addr[info->line];
249    unsigned long flags;
250    
251    if (serial_paranoia_check(info, tty->name, "rs_start"))
252        return;
253    
254    local_irq_save(flags);
255    if (info->xmit_cnt && info->xmit_buf && !(uart->ustcnt & USTCNT_TXEN)) {
256#ifdef USE_INTS
257        uart->ustcnt |= USTCNT_TXEN | USTCNT_TX_INTR_MASK;
258#else
259        uart->ustcnt |= USTCNT_TXEN;
260#endif
261    }
262    local_irq_restore(flags);
263}
264
265static void receive_chars(struct m68k_serial *info, unsigned short rx)
266{
267    m68328_uart *uart = &uart_addr[info->line];
268    unsigned char ch, flag;
269
270    /*
271     * This do { } while() loop will get ALL chars out of Rx FIFO
272         */
273#ifndef CONFIG_XCOPILOT_BUGS
274    do {
275#endif
276        ch = GET_FIELD(rx, URX_RXDATA);
277    
278        if(info->is_cons) {
279            if(URX_BREAK & rx) { /* whee, break received */
280                return;
281#ifdef CONFIG_MAGIC_SYSRQ
282            } else if (ch == 0x10) { /* ^P */
283                show_state();
284                show_free_areas(0);
285                show_buffers();
286/* show_net_buffers(); */
287                return;
288            } else if (ch == 0x12) { /* ^R */
289                emergency_restart();
290                return;
291#endif /* CONFIG_MAGIC_SYSRQ */
292            }
293        }
294
295        flag = TTY_NORMAL;
296
297        if (rx & URX_PARITY_ERROR)
298            flag = TTY_PARITY;
299        else if (rx & URX_OVRUN)
300            flag = TTY_OVERRUN;
301        else if (rx & URX_FRAME_ERROR)
302            flag = TTY_FRAME;
303
304        tty_insert_flip_char(&info->tport, ch, flag);
305#ifndef CONFIG_XCOPILOT_BUGS
306    } while((rx = uart->urx.w) & URX_DATA_READY);
307#endif
308
309    tty_schedule_flip(&info->tport);
310}
311
312static void transmit_chars(struct m68k_serial *info, struct tty_struct *tty)
313{
314    m68328_uart *uart = &uart_addr[info->line];
315
316    if (info->x_char) {
317        /* Send next char */
318        uart->utx.b.txdata = info->x_char;
319        info->x_char = 0;
320        goto clear_and_return;
321    }
322
323    if ((info->xmit_cnt <= 0) || !tty || tty->stopped) {
324        /* That's peculiar... TX ints off */
325        uart->ustcnt &= ~USTCNT_TX_INTR_MASK;
326        goto clear_and_return;
327    }
328
329    /* Send char */
330    uart->utx.b.txdata = info->xmit_buf[info->xmit_tail++];
331    info->xmit_tail = info->xmit_tail & (SERIAL_XMIT_SIZE-1);
332    info->xmit_cnt--;
333
334    if(info->xmit_cnt <= 0) {
335        /* All done for now... TX ints off */
336        uart->ustcnt &= ~USTCNT_TX_INTR_MASK;
337        goto clear_and_return;
338    }
339
340clear_and_return:
341    /* Clear interrupt (should be auto)*/
342    return;
343}
344
345/*
346 * This is the serial driver's generic interrupt routine
347 */
348irqreturn_t rs_interrupt(int irq, void *dev_id)
349{
350    struct m68k_serial *info = dev_id;
351    struct tty_struct *tty = tty_port_tty_get(&info->tport);
352    m68328_uart *uart;
353    unsigned short rx;
354    unsigned short tx;
355
356    uart = &uart_addr[info->line];
357    rx = uart->urx.w;
358
359#ifdef USE_INTS
360    tx = uart->utx.w;
361
362    if (rx & URX_DATA_READY)
363        receive_chars(info, rx);
364    if (tx & UTX_TX_AVAIL)
365        transmit_chars(info, tty);
366#else
367    receive_chars(info, rx);
368#endif
369    tty_kref_put(tty);
370
371    return IRQ_HANDLED;
372}
373
374static int startup(struct m68k_serial *info, struct tty_struct *tty)
375{
376    m68328_uart *uart = &uart_addr[info->line];
377    unsigned long flags;
378    
379    if (info->tport.flags & ASYNC_INITIALIZED)
380        return 0;
381
382    if (!info->xmit_buf) {
383        info->xmit_buf = (unsigned char *) __get_free_page(GFP_KERNEL);
384        if (!info->xmit_buf)
385            return -ENOMEM;
386    }
387
388    local_irq_save(flags);
389
390    /*
391     * Clear the FIFO buffers and disable them
392     * (they will be reenabled in change_speed())
393     */
394
395    uart->ustcnt = USTCNT_UEN;
396    uart->ustcnt = USTCNT_UEN | USTCNT_RXEN | USTCNT_TXEN;
397    (void)uart->urx.w;
398
399    /*
400     * Finally, enable sequencing and interrupts
401     */
402#ifdef USE_INTS
403    uart->ustcnt = USTCNT_UEN | USTCNT_RXEN |
404                 USTCNT_RX_INTR_MASK | USTCNT_TX_INTR_MASK;
405#else
406    uart->ustcnt = USTCNT_UEN | USTCNT_RXEN | USTCNT_RX_INTR_MASK;
407#endif
408
409    if (tty)
410        clear_bit(TTY_IO_ERROR, &tty->flags);
411    info->xmit_cnt = info->xmit_head = info->xmit_tail = 0;
412
413    /*
414     * and set the speed of the serial port
415     */
416
417    change_speed(info, tty);
418
419    info->tport.flags |= ASYNC_INITIALIZED;
420    local_irq_restore(flags);
421    return 0;
422}
423
424/*
425 * This routine will shutdown a serial port; interrupts are disabled, and
426 * DTR is dropped if the hangup on close termio flag is on.
427 */
428static void shutdown(struct m68k_serial *info, struct tty_struct *tty)
429{
430    m68328_uart *uart = &uart_addr[info->line];
431    unsigned long flags;
432
433    uart->ustcnt = 0; /* All off! */
434    if (!(info->tport.flags & ASYNC_INITIALIZED))
435        return;
436
437    local_irq_save(flags);
438    
439    if (info->xmit_buf) {
440        free_page((unsigned long) info->xmit_buf);
441        info->xmit_buf = 0;
442    }
443
444    if (tty)
445        set_bit(TTY_IO_ERROR, &tty->flags);
446    
447    info->tport.flags &= ~ASYNC_INITIALIZED;
448    local_irq_restore(flags);
449}
450
451struct {
452    int divisor, prescale;
453}
454#ifndef CONFIG_M68VZ328
455 hw_baud_table[18] = {
456    {0,0}, /* 0 */
457    {0,0}, /* 50 */
458    {0,0}, /* 75 */
459    {0,0}, /* 110 */
460    {0,0}, /* 134 */
461    {0,0}, /* 150 */
462    {0,0}, /* 200 */
463    {7,0x26}, /* 300 */
464    {6,0x26}, /* 600 */
465    {5,0x26}, /* 1200 */
466    {0,0}, /* 1800 */
467    {4,0x26}, /* 2400 */
468    {3,0x26}, /* 4800 */
469    {2,0x26}, /* 9600 */
470    {1,0x26}, /* 19200 */
471    {0,0x26}, /* 38400 */
472    {1,0x38}, /* 57600 */
473    {0,0x38}, /* 115200 */
474};
475#else
476 hw_baud_table[18] = {
477                 {0,0}, /* 0 */
478                 {0,0}, /* 50 */
479                 {0,0}, /* 75 */
480                 {0,0}, /* 110 */
481                 {0,0}, /* 134 */
482                 {0,0}, /* 150 */
483                 {0,0}, /* 200 */
484                 {0,0}, /* 300 */
485                 {7,0x26}, /* 600 */
486                 {6,0x26}, /* 1200 */
487                 {0,0}, /* 1800 */
488                 {5,0x26}, /* 2400 */
489                 {4,0x26}, /* 4800 */
490                 {3,0x26}, /* 9600 */
491                 {2,0x26}, /* 19200 */
492                 {1,0x26}, /* 38400 */
493                 {0,0x26}, /* 57600 */
494                 {1,0x38}, /* 115200 */
495};
496#endif
497/* rate = 1036800 / ((65 - prescale) * (1<<divider)) */
498
499/*
500 * This routine is called to set the UART divisor registers to match
501 * the specified baud rate for a serial port.
502 */
503static void change_speed(struct m68k_serial *info, struct tty_struct *tty)
504{
505    m68328_uart *uart = &uart_addr[info->line];
506    unsigned short port;
507    unsigned short ustcnt;
508    unsigned cflag;
509    int i;
510
511    cflag = tty->termios.c_cflag;
512    if (!(port = info->port))
513        return;
514
515    ustcnt = uart->ustcnt;
516    uart->ustcnt = ustcnt & ~USTCNT_TXEN;
517
518    i = cflag & CBAUD;
519        if (i & CBAUDEX) {
520                i = (i & ~CBAUDEX) + B38400;
521        }
522
523    uart->ubaud = PUT_FIELD(UBAUD_DIVIDE, hw_baud_table[i].divisor) |
524        PUT_FIELD(UBAUD_PRESCALER, hw_baud_table[i].prescale);
525
526    ustcnt &= ~(USTCNT_PARITYEN | USTCNT_ODD_EVEN | USTCNT_STOP | USTCNT_8_7);
527    
528    if ((cflag & CSIZE) == CS8)
529        ustcnt |= USTCNT_8_7;
530        
531    if (cflag & CSTOPB)
532        ustcnt |= USTCNT_STOP;
533
534    if (cflag & PARENB)
535        ustcnt |= USTCNT_PARITYEN;
536    if (cflag & PARODD)
537        ustcnt |= USTCNT_ODD_EVEN;
538    
539#ifdef CONFIG_SERIAL_68328_RTS_CTS
540    if (cflag & CRTSCTS) {
541        uart->utx.w &= ~ UTX_NOCTS;
542    } else {
543        uart->utx.w |= UTX_NOCTS;
544    }
545#endif
546
547    ustcnt |= USTCNT_TXEN;
548    
549    uart->ustcnt = ustcnt;
550    return;
551}
552
553/*
554 * Fair output driver allows a process to speak.
555 */
556static void rs_fair_output(void)
557{
558    int left; /* Output no more than that */
559    unsigned long flags;
560    struct m68k_serial *info = &m68k_soft[0];
561    char c;
562
563    if (info == 0) return;
564    if (info->xmit_buf == 0) return;
565
566    local_irq_save(flags);
567    left = info->xmit_cnt;
568    while (left != 0) {
569        c = info->xmit_buf[info->xmit_tail];
570        info->xmit_tail = (info->xmit_tail+1) & (SERIAL_XMIT_SIZE-1);
571        info->xmit_cnt--;
572        local_irq_restore(flags);
573
574        rs_put_char(c);
575
576        local_irq_save(flags);
577        left = min(info->xmit_cnt, left-1);
578    }
579
580    /* Last character is being transmitted now (hopefully). */
581    udelay(5);
582
583    local_irq_restore(flags);
584    return;
585}
586
587/*
588 * m68k_console_print is registered for printk.
589 */
590void console_print_68328(const char *p)
591{
592    char c;
593    
594    while((c=*(p++)) != 0) {
595        if(c == '\n')
596            rs_put_char('\r');
597        rs_put_char(c);
598    }
599
600    /* Comment this if you want to have a strict interrupt-driven output */
601    rs_fair_output();
602
603    return;
604}
605
606static void rs_set_ldisc(struct tty_struct *tty)
607{
608    struct m68k_serial *info = (struct m68k_serial *)tty->driver_data;
609
610    if (serial_paranoia_check(info, tty->name, "rs_set_ldisc"))
611        return;
612
613    info->is_cons = (tty->termios.c_line == N_TTY);
614    
615    printk("ttyS%d console mode %s\n", info->line, info->is_cons ? "on" : "off");
616}
617
618static void rs_flush_chars(struct tty_struct *tty)
619{
620    struct m68k_serial *info = (struct m68k_serial *)tty->driver_data;
621    m68328_uart *uart = &uart_addr[info->line];
622    unsigned long flags;
623
624    if (serial_paranoia_check(info, tty->name, "rs_flush_chars"))
625        return;
626#ifndef USE_INTS
627    for(;;) {
628#endif
629
630    /* Enable transmitter */
631    local_irq_save(flags);
632
633    if (info->xmit_cnt <= 0 || tty->stopped || tty->hw_stopped ||
634            !info->xmit_buf) {
635        local_irq_restore(flags);
636        return;
637    }
638
639#ifdef USE_INTS
640    uart->ustcnt |= USTCNT_TXEN | USTCNT_TX_INTR_MASK;
641#else
642    uart->ustcnt |= USTCNT_TXEN;
643#endif
644
645#ifdef USE_INTS
646    if (uart->utx.w & UTX_TX_AVAIL) {
647#else
648    if (1) {
649#endif
650        /* Send char */
651        uart->utx.b.txdata = info->xmit_buf[info->xmit_tail++];
652        info->xmit_tail = info->xmit_tail & (SERIAL_XMIT_SIZE-1);
653        info->xmit_cnt--;
654    }
655
656#ifndef USE_INTS
657    while (!(uart->utx.w & UTX_TX_AVAIL)) udelay(5);
658    }
659#endif
660    local_irq_restore(flags);
661}
662
663extern void console_printn(const char * b, int count);
664
665static int rs_write(struct tty_struct * tty,
666            const unsigned char *buf, int count)
667{
668    int c, total = 0;
669    struct m68k_serial *info = (struct m68k_serial *)tty->driver_data;
670    m68328_uart *uart = &uart_addr[info->line];
671    unsigned long flags;
672
673    if (serial_paranoia_check(info, tty->name, "rs_write"))
674        return 0;
675
676    if (!tty || !info->xmit_buf)
677        return 0;
678
679    local_save_flags(flags);
680    while (1) {
681        local_irq_disable();
682        c = min_t(int, count, min(SERIAL_XMIT_SIZE - info->xmit_cnt - 1,
683                   SERIAL_XMIT_SIZE - info->xmit_head));
684        local_irq_restore(flags);
685
686        if (c <= 0)
687            break;
688
689        memcpy(info->xmit_buf + info->xmit_head, buf, c);
690
691        local_irq_disable();
692        info->xmit_head = (info->xmit_head + c) & (SERIAL_XMIT_SIZE-1);
693        info->xmit_cnt += c;
694        local_irq_restore(flags);
695        buf += c;
696        count -= c;
697        total += c;
698    }
699
700    if (info->xmit_cnt && !tty->stopped && !tty->hw_stopped) {
701        /* Enable transmitter */
702        local_irq_disable();
703#ifndef USE_INTS
704        while(info->xmit_cnt) {
705#endif
706
707        uart->ustcnt |= USTCNT_TXEN;
708#ifdef USE_INTS
709        uart->ustcnt |= USTCNT_TX_INTR_MASK;
710#else
711        while (!(uart->utx.w & UTX_TX_AVAIL)) udelay(5);
712#endif
713        if (uart->utx.w & UTX_TX_AVAIL) {
714            uart->utx.b.txdata = info->xmit_buf[info->xmit_tail++];
715            info->xmit_tail = info->xmit_tail & (SERIAL_XMIT_SIZE-1);
716            info->xmit_cnt--;
717        }
718
719#ifndef USE_INTS
720        }
721#endif
722        local_irq_restore(flags);
723    }
724
725    return total;
726}
727
728static int rs_write_room(struct tty_struct *tty)
729{
730    struct m68k_serial *info = (struct m68k_serial *)tty->driver_data;
731    int ret;
732                
733    if (serial_paranoia_check(info, tty->name, "rs_write_room"))
734        return 0;
735    ret = SERIAL_XMIT_SIZE - info->xmit_cnt - 1;
736    if (ret < 0)
737        ret = 0;
738    return ret;
739}
740
741static int rs_chars_in_buffer(struct tty_struct *tty)
742{
743    struct m68k_serial *info = (struct m68k_serial *)tty->driver_data;
744                
745    if (serial_paranoia_check(info, tty->name, "rs_chars_in_buffer"))
746        return 0;
747    return info->xmit_cnt;
748}
749
750static void rs_flush_buffer(struct tty_struct *tty)
751{
752    struct m68k_serial *info = (struct m68k_serial *)tty->driver_data;
753    unsigned long flags;
754                
755    if (serial_paranoia_check(info, tty->name, "rs_flush_buffer"))
756        return;
757    local_irq_save(flags);
758    info->xmit_cnt = info->xmit_head = info->xmit_tail = 0;
759    local_irq_restore(flags);
760    tty_wakeup(tty);
761}
762
763/*
764 * ------------------------------------------------------------
765 * rs_throttle()
766 *
767 * This routine is called by the upper-layer tty layer to signal that
768 * incoming characters should be throttled.
769 * ------------------------------------------------------------
770 */
771static void rs_throttle(struct tty_struct * tty)
772{
773    struct m68k_serial *info = (struct m68k_serial *)tty->driver_data;
774
775    if (serial_paranoia_check(info, tty->name, "rs_throttle"))
776        return;
777    
778    if (I_IXOFF(tty))
779        info->x_char = STOP_CHAR(tty);
780
781    /* Turn off RTS line (do this atomic) */
782}
783
784static void rs_unthrottle(struct tty_struct * tty)
785{
786    struct m68k_serial *info = (struct m68k_serial *)tty->driver_data;
787
788    if (serial_paranoia_check(info, tty->name, "rs_unthrottle"))
789        return;
790    
791    if (I_IXOFF(tty)) {
792        if (info->x_char)
793            info->x_char = 0;
794        else
795            info->x_char = START_CHAR(tty);
796    }
797
798    /* Assert RTS line (do this atomic) */
799}
800
801/*
802 * ------------------------------------------------------------
803 * rs_ioctl() and friends
804 * ------------------------------------------------------------
805 */
806
807static int get_serial_info(struct m68k_serial * info,
808               struct serial_struct * retinfo)
809{
810    struct serial_struct tmp;
811  
812    if (!retinfo)
813        return -EFAULT;
814    memset(&tmp, 0, sizeof(tmp));
815    tmp.type = info->type;
816    tmp.line = info->line;
817    tmp.port = info->port;
818    tmp.irq = info->irq;
819    tmp.flags = info->tport.flags;
820    tmp.baud_base = info->baud_base;
821    tmp.close_delay = info->tport.close_delay;
822    tmp.closing_wait = info->tport.closing_wait;
823    tmp.custom_divisor = info->custom_divisor;
824    if (copy_to_user(retinfo, &tmp, sizeof(*retinfo)))
825        return -EFAULT;
826
827    return 0;
828}
829
830static int set_serial_info(struct m68k_serial *info, struct tty_struct *tty,
831               struct serial_struct * new_info)
832{
833    struct tty_port *port = &info->tport;
834    struct serial_struct new_serial;
835    struct m68k_serial old_info;
836    int retval = 0;
837
838    if (!new_info)
839        return -EFAULT;
840    if (copy_from_user(&new_serial, new_info, sizeof(new_serial)))
841        return -EFAULT;
842    old_info = *info;
843
844    if (!capable(CAP_SYS_ADMIN)) {
845        if ((new_serial.baud_base != info->baud_base) ||
846            (new_serial.type != info->type) ||
847            (new_serial.close_delay != port->close_delay) ||
848            ((new_serial.flags & ~ASYNC_USR_MASK) !=
849             (port->flags & ~ASYNC_USR_MASK)))
850            return -EPERM;
851        port->flags = ((port->flags & ~ASYNC_USR_MASK) |
852                   (new_serial.flags & ASYNC_USR_MASK));
853        info->custom_divisor = new_serial.custom_divisor;
854        goto check_and_exit;
855    }
856
857    if (port->count > 1)
858        return -EBUSY;
859
860    /*
861     * OK, past this point, all the error checking has been done.
862     * At this point, we start making changes.....
863     */
864
865    info->baud_base = new_serial.baud_base;
866    port->flags = ((port->flags & ~ASYNC_FLAGS) |
867            (new_serial.flags & ASYNC_FLAGS));
868    info->type = new_serial.type;
869    port->close_delay = new_serial.close_delay;
870    port->closing_wait = new_serial.closing_wait;
871
872check_and_exit:
873    retval = startup(info, tty);
874    return retval;
875}
876
877/*
878 * get_lsr_info - get line status register info
879 *
880 * Purpose: Let user call ioctl() to get info when the UART physically
881 * is emptied. On bus types like RS485, the transmitter must
882 * release the bus after transmitting. This must be done when
883 * the transmit shift register is empty, not be done when the
884 * transmit holding register is empty. This functionality
885 * allows an RS485 driver to be written in user space.
886 */
887static int get_lsr_info(struct m68k_serial * info, unsigned int *value)
888{
889#ifdef CONFIG_SERIAL_68328_RTS_CTS
890    m68328_uart *uart = &uart_addr[info->line];
891#endif
892    unsigned char status;
893    unsigned long flags;
894
895    local_irq_save(flags);
896#ifdef CONFIG_SERIAL_68328_RTS_CTS
897    status = (uart->utx.w & UTX_CTS_STAT) ? 1 : 0;
898#else
899    status = 0;
900#endif
901    local_irq_restore(flags);
902    return put_user(status, value);
903}
904
905/*
906 * This routine sends a break character out the serial port.
907 */
908static void send_break(struct m68k_serial * info, unsigned int duration)
909{
910    m68328_uart *uart = &uart_addr[info->line];
911        unsigned long flags;
912        if (!info->port)
913                return;
914        local_irq_save(flags);
915#ifdef USE_INTS
916    uart->utx.w |= UTX_SEND_BREAK;
917    msleep_interruptible(duration);
918    uart->utx.w &= ~UTX_SEND_BREAK;
919#endif
920        local_irq_restore(flags);
921}
922
923static int rs_ioctl(struct tty_struct *tty,
924            unsigned int cmd, unsigned long arg)
925{
926    struct m68k_serial * info = (struct m68k_serial *)tty->driver_data;
927    int retval;
928
929    if (serial_paranoia_check(info, tty->name, "rs_ioctl"))
930        return -ENODEV;
931
932    if ((cmd != TIOCGSERIAL) && (cmd != TIOCSSERIAL) &&
933        (cmd != TIOCSERCONFIG) && (cmd != TIOCSERGWILD) &&
934        (cmd != TIOCSERSWILD) && (cmd != TIOCSERGSTRUCT)) {
935        if (tty->flags & (1 << TTY_IO_ERROR))
936            return -EIO;
937    }
938    
939    switch (cmd) {
940        case TCSBRK: /* SVID version: non-zero arg --> no break */
941            retval = tty_check_change(tty);
942            if (retval)
943                return retval;
944            tty_wait_until_sent(tty, 0);
945            if (!arg)
946                send_break(info, 250); /* 1/4 second */
947            return 0;
948        case TCSBRKP: /* support for POSIX tcsendbreak() */
949            retval = tty_check_change(tty);
950            if (retval)
951                return retval;
952            tty_wait_until_sent(tty, 0);
953            send_break(info, arg ? arg*(100) : 250);
954            return 0;
955        case TIOCGSERIAL:
956            return get_serial_info(info,
957                       (struct serial_struct *) arg);
958        case TIOCSSERIAL:
959            return set_serial_info(info, tty,
960                           (struct serial_struct *) arg);
961        case TIOCSERGETLSR: /* Get line status register */
962            return get_lsr_info(info, (unsigned int *) arg);
963        case TIOCSERGSTRUCT:
964            if (copy_to_user((struct m68k_serial *) arg,
965                    info, sizeof(struct m68k_serial)))
966                return -EFAULT;
967            return 0;
968        default:
969            return -ENOIOCTLCMD;
970        }
971    return 0;
972}
973
974static void rs_set_termios(struct tty_struct *tty, struct ktermios *old_termios)
975{
976    struct m68k_serial *info = (struct m68k_serial *)tty->driver_data;
977
978    change_speed(info, tty);
979
980    if ((old_termios->c_cflag & CRTSCTS) &&
981        !(tty->termios.c_cflag & CRTSCTS)) {
982        tty->hw_stopped = 0;
983        rs_start(tty);
984    }
985    
986}
987
988/*
989 * ------------------------------------------------------------
990 * rs_close()
991 *
992 * This routine is called when the serial port gets closed. First, we
993 * wait for the last remaining data to be sent. Then, we unlink its
994 * S structure from the interrupt chain if necessary, and we free
995 * that IRQ if nothing is left in the chain.
996 * ------------------------------------------------------------
997 */
998static void rs_close(struct tty_struct *tty, struct file * filp)
999{
1000    struct m68k_serial * info = (struct m68k_serial *)tty->driver_data;
1001    struct tty_port *port = &info->tport;
1002    m68328_uart *uart = &uart_addr[info->line];
1003    unsigned long flags;
1004
1005    if (serial_paranoia_check(info, tty->name, "rs_close"))
1006        return;
1007    
1008    local_irq_save(flags);
1009    
1010    if (tty_hung_up_p(filp)) {
1011        local_irq_restore(flags);
1012        return;
1013    }
1014    
1015    if ((tty->count == 1) && (port->count != 1)) {
1016        /*
1017         * Uh, oh. tty->count is 1, which means that the tty
1018         * structure will be freed. Info->count should always
1019         * be one in these conditions. If it's greater than
1020         * one, we've got real problems, since it means the
1021         * serial port won't be shutdown.
1022         */
1023        printk("rs_close: bad serial port count; tty->count is 1, "
1024               "port->count is %d\n", port->count);
1025        port->count = 1;
1026    }
1027    if (--port->count < 0) {
1028        printk("rs_close: bad serial port count for ttyS%d: %d\n",
1029               info->line, port->count);
1030        port->count = 0;
1031    }
1032    if (port->count) {
1033        local_irq_restore(flags);
1034        return;
1035    }
1036    port->flags |= ASYNC_CLOSING;
1037    /*
1038     * Now we wait for the transmit buffer to clear; and we notify
1039     * the line discipline to only process XON/XOFF characters.
1040     */
1041    tty->closing = 1;
1042    if (port->closing_wait != ASYNC_CLOSING_WAIT_NONE)
1043        tty_wait_until_sent(tty, port->closing_wait);
1044    /*
1045     * At this point we stop accepting input. To do this, we
1046     * disable the receive line status interrupts, and tell the
1047     * interrupt driver to stop checking the data ready bit in the
1048     * line status register.
1049     */
1050
1051    uart->ustcnt &= ~USTCNT_RXEN;
1052    uart->ustcnt &= ~(USTCNT_RXEN | USTCNT_RX_INTR_MASK);
1053
1054    shutdown(info, tty);
1055    rs_flush_buffer(tty);
1056        
1057    tty_ldisc_flush(tty);
1058    tty->closing = 0;
1059    tty_port_tty_set(&info->tport, NULL);
1060#warning "This is not and has never been valid so fix it"
1061#if 0
1062    if (tty->ldisc.num != ldiscs[N_TTY].num) {
1063        if (tty->ldisc.close)
1064            (tty->ldisc.close)(tty);
1065        tty->ldisc = ldiscs[N_TTY];
1066        tty->termios.c_line = N_TTY;
1067        if (tty->ldisc.open)
1068            (tty->ldisc.open)(tty);
1069    }
1070#endif
1071    if (port->blocked_open) {
1072        if (port->close_delay)
1073            msleep_interruptible(jiffies_to_msecs(port->close_delay));
1074        wake_up_interruptible(&port->open_wait);
1075    }
1076    port->flags &= ~(ASYNC_NORMAL_ACTIVE|ASYNC_CLOSING);
1077    wake_up_interruptible(&port->close_wait);
1078    local_irq_restore(flags);
1079}
1080
1081/*
1082 * rs_hangup() --- called by tty_hangup() when a hangup is signaled.
1083 */
1084void rs_hangup(struct tty_struct *tty)
1085{
1086    struct m68k_serial * info = (struct m68k_serial *)tty->driver_data;
1087    
1088    if (serial_paranoia_check(info, tty->name, "rs_hangup"))
1089        return;
1090    
1091    rs_flush_buffer(tty);
1092    shutdown(info, tty);
1093    info->tport.count = 0;
1094    info->tport.flags &= ~ASYNC_NORMAL_ACTIVE;
1095    tty_port_tty_set(&info->tport, NULL);
1096    wake_up_interruptible(&info->tport.open_wait);
1097}
1098
1099/*
1100 * This routine is called whenever a serial port is opened. It
1101 * enables interrupts for a serial port, linking in its S structure into
1102 * the IRQ chain. It also performs the serial-specific
1103 * initialization for the tty structure.
1104 */
1105int rs_open(struct tty_struct *tty, struct file * filp)
1106{
1107    struct m68k_serial *info;
1108    int retval;
1109
1110    info = &m68k_soft[tty->index];
1111
1112    if (serial_paranoia_check(info, tty->name, "rs_open"))
1113        return -ENODEV;
1114
1115    info->tport.count++;
1116    tty->driver_data = info;
1117    tty_port_tty_set(&info->tport, tty);
1118
1119    /*
1120     * Start up serial port
1121     */
1122    retval = startup(info, tty);
1123    if (retval)
1124        return retval;
1125
1126    return tty_port_block_til_ready(&info->tport, tty, filp);
1127}
1128
1129/* Finally, routines used to initialize the serial driver. */
1130
1131static void show_serial_version(void)
1132{
1133    printk("MC68328 serial driver version 1.00\n");
1134}
1135
1136static const struct tty_operations rs_ops = {
1137    .open = rs_open,
1138    .close = rs_close,
1139    .write = rs_write,
1140    .flush_chars = rs_flush_chars,
1141    .write_room = rs_write_room,
1142    .chars_in_buffer = rs_chars_in_buffer,
1143    .flush_buffer = rs_flush_buffer,
1144    .ioctl = rs_ioctl,
1145    .throttle = rs_throttle,
1146    .unthrottle = rs_unthrottle,
1147    .set_termios = rs_set_termios,
1148    .stop = rs_stop,
1149    .start = rs_start,
1150    .hangup = rs_hangup,
1151    .set_ldisc = rs_set_ldisc,
1152};
1153
1154static const struct tty_port_operations rs_port_ops = {
1155};
1156
1157/* rs_init inits the driver */
1158static int __init
1159rs68328_init(void)
1160{
1161    unsigned long flags;
1162    int i;
1163    struct m68k_serial *info;
1164
1165    serial_driver = alloc_tty_driver(NR_PORTS);
1166    if (!serial_driver)
1167        return -ENOMEM;
1168
1169    show_serial_version();
1170
1171    /* Initialize the tty_driver structure */
1172    /* SPARC: Not all of this is exactly right for us. */
1173    
1174    serial_driver->name = "ttyS";
1175    serial_driver->major = TTY_MAJOR;
1176    serial_driver->minor_start = 64;
1177    serial_driver->type = TTY_DRIVER_TYPE_SERIAL;
1178    serial_driver->subtype = SERIAL_TYPE_NORMAL;
1179    serial_driver->init_termios = tty_std_termios;
1180    serial_driver->init_termios.c_cflag =
1181            m68328_console_cbaud | CS8 | CREAD | HUPCL | CLOCAL;
1182    serial_driver->flags = TTY_DRIVER_REAL_RAW;
1183    tty_set_operations(serial_driver, &rs_ops);
1184
1185    local_irq_save(flags);
1186
1187    for(i=0;i<NR_PORTS;i++) {
1188
1189        info = &m68k_soft[i];
1190        tty_port_init(&info->tport);
1191        info->tport.ops = &rs_port_ops;
1192        info->magic = SERIAL_MAGIC;
1193        info->port = (int) &uart_addr[i];
1194        info->irq = uart_irqs[i];
1195        info->custom_divisor = 16;
1196        info->x_char = 0;
1197        info->line = i;
1198        info->is_cons = 1; /* Means shortcuts work */
1199        
1200        printk("%s%d at 0x%08x (irq = %d)", serial_driver->name, info->line,
1201           info->port, info->irq);
1202        printk(" is a builtin MC68328 UART\n");
1203        
1204#ifdef CONFIG_M68VZ328
1205        if (i > 0 )
1206            PJSEL &= 0xCF; /* PSW enable second port output */
1207#endif
1208
1209        if (request_irq(uart_irqs[i],
1210                rs_interrupt,
1211                0,
1212                "M68328_UART", info))
1213                panic("Unable to attach 68328 serial interrupt\n");
1214
1215        tty_port_link_device(&info->tport, serial_driver, i);
1216    }
1217    local_irq_restore(flags);
1218
1219    if (tty_register_driver(serial_driver)) {
1220        put_tty_driver(serial_driver);
1221        for (i = 0; i < NR_PORTS; i++)
1222            tty_port_destroy(&m68k_soft[i].tport);
1223        printk(KERN_ERR "Couldn't register serial driver\n");
1224        return -ENOMEM;
1225    }
1226
1227    return 0;
1228}
1229
1230module_init(rs68328_init);
1231
1232
1233
1234static void m68328_set_baud(void)
1235{
1236    unsigned short ustcnt;
1237    int i;
1238
1239    ustcnt = USTCNT;
1240    USTCNT = ustcnt & ~USTCNT_TXEN;
1241
1242again:
1243    for (i = 0; i < ARRAY_SIZE(baud_table); i++)
1244        if (baud_table[i] == m68328_console_baud)
1245            break;
1246    if (i >= ARRAY_SIZE(baud_table)) {
1247        m68328_console_baud = 9600;
1248        goto again;
1249    }
1250
1251    UBAUD = PUT_FIELD(UBAUD_DIVIDE, hw_baud_table[i].divisor) |
1252        PUT_FIELD(UBAUD_PRESCALER, hw_baud_table[i].prescale);
1253    ustcnt &= ~(USTCNT_PARITYEN | USTCNT_ODD_EVEN | USTCNT_STOP | USTCNT_8_7);
1254    ustcnt |= USTCNT_8_7;
1255    ustcnt |= USTCNT_TXEN;
1256    USTCNT = ustcnt;
1257    m68328_console_initted = 1;
1258    return;
1259}
1260
1261
1262int m68328_console_setup(struct console *cp, char *arg)
1263{
1264    int i, n = CONSOLE_BAUD_RATE;
1265
1266    if (!cp)
1267        return(-1);
1268
1269    if (arg)
1270        n = simple_strtoul(arg,NULL,0);
1271
1272    for (i = 0; i < ARRAY_SIZE(baud_table); i++)
1273        if (baud_table[i] == n)
1274            break;
1275    if (i < ARRAY_SIZE(baud_table)) {
1276        m68328_console_baud = n;
1277        m68328_console_cbaud = 0;
1278        if (i > 15) {
1279            m68328_console_cbaud |= CBAUDEX;
1280            i -= 15;
1281        }
1282        m68328_console_cbaud |= i;
1283    }
1284
1285    m68328_set_baud(); /* make sure baud rate changes */
1286    return(0);
1287}
1288
1289
1290static struct tty_driver *m68328_console_device(struct console *c, int *index)
1291{
1292    *index = c->index;
1293    return serial_driver;
1294}
1295
1296
1297void m68328_console_write (struct console *co, const char *str,
1298               unsigned int count)
1299{
1300    if (!m68328_console_initted)
1301        m68328_set_baud();
1302    while (count--) {
1303        if (*str == '\n')
1304           rs_put_char('\r');
1305        rs_put_char( *str++ );
1306    }
1307}
1308
1309
1310static struct console m68328_driver = {
1311    .name = "ttyS",
1312    .write = m68328_console_write,
1313    .device = m68328_console_device,
1314    .setup = m68328_console_setup,
1315    .flags = CON_PRINTBUFFER,
1316    .index = -1,
1317};
1318
1319
1320static int __init m68328_console_init(void)
1321{
1322    register_console(&m68328_driver);
1323    return 0;
1324}
1325
1326console_initcall(m68328_console_init);
1327

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