merge linus into release branch
[linux-2.6] / drivers / serial / sunsab.c
1 /* sunsab.c: ASYNC Driver for the SIEMENS SAB82532 DUSCC.
2  *
3  * Copyright (C) 1997  Eddie C. Dost  (ecd@skynet.be)
4  * Copyright (C) 2002  David S. Miller (davem@redhat.com)
5  *
6  * Rewrote buffer handling to use CIRC(Circular Buffer) macros.
7  *   Maxim Krasnyanskiy <maxk@qualcomm.com>
8  *
9  * Fixed to use tty_get_baud_rate, and to allow for arbitrary baud
10  * rates to be programmed into the UART.  Also eliminated a lot of
11  * duplicated code in the console setup.
12  *   Theodore Ts'o <tytso@mit.edu>, 2001-Oct-12
13  *
14  * Ported to new 2.5.x UART layer.
15  *   David S. Miller <davem@redhat.com>
16  */
17
18 #include <linux/config.h>
19 #include <linux/module.h>
20 #include <linux/kernel.h>
21 #include <linux/sched.h>
22 #include <linux/errno.h>
23 #include <linux/tty.h>
24 #include <linux/tty_flip.h>
25 #include <linux/major.h>
26 #include <linux/string.h>
27 #include <linux/ptrace.h>
28 #include <linux/ioport.h>
29 #include <linux/circ_buf.h>
30 #include <linux/serial.h>
31 #include <linux/sysrq.h>
32 #include <linux/console.h>
33 #include <linux/spinlock.h>
34 #include <linux/slab.h>
35 #include <linux/delay.h>
36 #include <linux/init.h>
37
38 #include <asm/io.h>
39 #include <asm/irq.h>
40 #include <asm/oplib.h>
41 #include <asm/ebus.h>
42
43 #if defined(CONFIG_SERIAL_SUNZILOG_CONSOLE) && defined(CONFIG_MAGIC_SYSRQ)
44 #define SUPPORT_SYSRQ
45 #endif
46
47 #include <linux/serial_core.h>
48
49 #include "suncore.h"
50 #include "sunsab.h"
51
52 struct uart_sunsab_port {
53         struct uart_port                port;           /* Generic UART port    */
54         union sab82532_async_regs       __iomem *regs;  /* Chip registers       */
55         unsigned long                   irqflags;       /* IRQ state flags      */
56         int                             dsr;            /* Current DSR state    */
57         unsigned int                    cec_timeout;    /* Chip poll timeout... */
58         unsigned int                    tec_timeout;    /* likewise             */
59         unsigned char                   interrupt_mask0;/* ISR0 masking         */
60         unsigned char                   interrupt_mask1;/* ISR1 masking         */
61         unsigned char                   pvr_dtr_bit;    /* Which PVR bit is DTR */
62         unsigned char                   pvr_dsr_bit;    /* Which PVR bit is DSR */
63         int                             type;           /* SAB82532 version     */
64
65         /* Setting configuration bits while the transmitter is active
66          * can cause garbage characters to get emitted by the chip.
67          * Therefore, we cache such writes here and do the real register
68          * write the next time the transmitter becomes idle.
69          */
70         unsigned int                    cached_ebrg;
71         unsigned char                   cached_mode;
72         unsigned char                   cached_pvr;
73         unsigned char                   cached_dafo;
74 };
75
76 /*
77  * This assumes you have a 29.4912 MHz clock for your UART.
78  */
79 #define SAB_BASE_BAUD ( 29491200 / 16 )
80
81 static char *sab82532_version[16] = {
82         "V1.0", "V2.0", "V3.2", "V(0x03)",
83         "V(0x04)", "V(0x05)", "V(0x06)", "V(0x07)",
84         "V(0x08)", "V(0x09)", "V(0x0a)", "V(0x0b)",
85         "V(0x0c)", "V(0x0d)", "V(0x0e)", "V(0x0f)"
86 };
87
88 #define SAB82532_MAX_TEC_TIMEOUT 200000 /* 1 character time (at 50 baud) */
89 #define SAB82532_MAX_CEC_TIMEOUT  50000 /* 2.5 TX CLKs (at 50 baud) */
90
91 #define SAB82532_RECV_FIFO_SIZE 32      /* Standard async fifo sizes */
92 #define SAB82532_XMIT_FIFO_SIZE 32
93
94 static __inline__ void sunsab_tec_wait(struct uart_sunsab_port *up)
95 {
96         int timeout = up->tec_timeout;
97
98         while ((readb(&up->regs->r.star) & SAB82532_STAR_TEC) && --timeout)
99                 udelay(1);
100 }
101
102 static __inline__ void sunsab_cec_wait(struct uart_sunsab_port *up)
103 {
104         int timeout = up->cec_timeout;
105
106         while ((readb(&up->regs->r.star) & SAB82532_STAR_CEC) && --timeout)
107                 udelay(1);
108 }
109
110 static struct tty_struct *
111 receive_chars(struct uart_sunsab_port *up,
112               union sab82532_irq_status *stat,
113               struct pt_regs *regs)
114 {
115         struct tty_struct *tty = NULL;
116         unsigned char buf[32];
117         int saw_console_brk = 0;
118         int free_fifo = 0;
119         int count = 0;
120         int i;
121
122         if (up->port.info != NULL)              /* Unopened serial console */
123                 tty = up->port.info->tty;
124
125         /* Read number of BYTES (Character + Status) available. */
126         if (stat->sreg.isr0 & SAB82532_ISR0_RPF) {
127                 count = SAB82532_RECV_FIFO_SIZE;
128                 free_fifo++;
129         }
130
131         if (stat->sreg.isr0 & SAB82532_ISR0_TCD) {
132                 count = readb(&up->regs->r.rbcl) & (SAB82532_RECV_FIFO_SIZE - 1);
133                 free_fifo++;
134         }
135
136         /* Issue a FIFO read command in case we where idle. */
137         if (stat->sreg.isr0 & SAB82532_ISR0_TIME) {
138                 sunsab_cec_wait(up);
139                 writeb(SAB82532_CMDR_RFRD, &up->regs->w.cmdr);
140                 return tty;
141         }
142
143         if (stat->sreg.isr0 & SAB82532_ISR0_RFO)
144                 free_fifo++;
145
146         /* Read the FIFO. */
147         for (i = 0; i < count; i++)
148                 buf[i] = readb(&up->regs->r.rfifo[i]);
149
150         /* Issue Receive Message Complete command. */
151         if (free_fifo) {
152                 sunsab_cec_wait(up);
153                 writeb(SAB82532_CMDR_RMC, &up->regs->w.cmdr);
154         }
155
156         /* Count may be zero for BRK, so we check for it here */
157         if ((stat->sreg.isr1 & SAB82532_ISR1_BRK) &&
158             (up->port.line == up->port.cons->index))
159                 saw_console_brk = 1;
160
161         for (i = 0; i < count; i++) {
162                 unsigned char ch = buf[i], flag;
163
164                 if (tty == NULL) {
165                         uart_handle_sysrq_char(&up->port, ch, regs);
166                         continue;
167                 }
168
169                 flag = TTY_NORMAL;
170                 up->port.icount.rx++;
171
172                 if (unlikely(stat->sreg.isr0 & (SAB82532_ISR0_PERR |
173                                                 SAB82532_ISR0_FERR |
174                                                 SAB82532_ISR0_RFO)) ||
175                     unlikely(stat->sreg.isr1 & SAB82532_ISR1_BRK)) {
176                         /*
177                          * For statistics only
178                          */
179                         if (stat->sreg.isr1 & SAB82532_ISR1_BRK) {
180                                 stat->sreg.isr0 &= ~(SAB82532_ISR0_PERR |
181                                                      SAB82532_ISR0_FERR);
182                                 up->port.icount.brk++;
183                                 /*
184                                  * We do the SysRQ and SAK checking
185                                  * here because otherwise the break
186                                  * may get masked by ignore_status_mask
187                                  * or read_status_mask.
188                                  */
189                                 if (uart_handle_break(&up->port))
190                                         continue;
191                         } else if (stat->sreg.isr0 & SAB82532_ISR0_PERR)
192                                 up->port.icount.parity++;
193                         else if (stat->sreg.isr0 & SAB82532_ISR0_FERR)
194                                 up->port.icount.frame++;
195                         if (stat->sreg.isr0 & SAB82532_ISR0_RFO)
196                                 up->port.icount.overrun++;
197
198                         /*
199                          * Mask off conditions which should be ingored.
200                          */
201                         stat->sreg.isr0 &= (up->port.read_status_mask & 0xff);
202                         stat->sreg.isr1 &= ((up->port.read_status_mask >> 8) & 0xff);
203
204                         if (stat->sreg.isr1 & SAB82532_ISR1_BRK) {
205                                 flag = TTY_BREAK;
206                         } else if (stat->sreg.isr0 & SAB82532_ISR0_PERR)
207                                 flag = TTY_PARITY;
208                         else if (stat->sreg.isr0 & SAB82532_ISR0_FERR)
209                                 flag = TTY_FRAME;
210                 }
211
212                 if (uart_handle_sysrq_char(&up->port, ch, regs))
213                         continue;
214
215                 if ((stat->sreg.isr0 & (up->port.ignore_status_mask & 0xff)) == 0 &&
216                     (stat->sreg.isr1 & ((up->port.ignore_status_mask >> 8) & 0xff)) == 0)
217                         tty_insert_flip_char(tty, ch, flag);
218                 if (stat->sreg.isr0 & SAB82532_ISR0_RFO)
219                         tty_insert_flip_char(tty, 0, TTY_OVERRUN);
220         }
221
222         if (saw_console_brk)
223                 sun_do_break();
224
225         return tty;
226 }
227
228 static void sunsab_stop_tx(struct uart_port *);
229 static void sunsab_tx_idle(struct uart_sunsab_port *);
230
231 static void transmit_chars(struct uart_sunsab_port *up,
232                            union sab82532_irq_status *stat)
233 {
234         struct circ_buf *xmit = &up->port.info->xmit;
235         int i;
236
237         if (stat->sreg.isr1 & SAB82532_ISR1_ALLS) {
238                 up->interrupt_mask1 |= SAB82532_IMR1_ALLS;
239                 writeb(up->interrupt_mask1, &up->regs->w.imr1);
240                 set_bit(SAB82532_ALLS, &up->irqflags);
241         }
242
243 #if 0 /* bde@nwlink.com says this check causes problems */
244         if (!(stat->sreg.isr1 & SAB82532_ISR1_XPR))
245                 return;
246 #endif
247
248         if (!(readb(&up->regs->r.star) & SAB82532_STAR_XFW))
249                 return;
250
251         set_bit(SAB82532_XPR, &up->irqflags);
252         sunsab_tx_idle(up);
253
254         if (uart_circ_empty(xmit) || uart_tx_stopped(&up->port)) {
255                 up->interrupt_mask1 |= SAB82532_IMR1_XPR;
256                 writeb(up->interrupt_mask1, &up->regs->w.imr1);
257                 return;
258         }
259
260         up->interrupt_mask1 &= ~(SAB82532_IMR1_ALLS|SAB82532_IMR1_XPR);
261         writeb(up->interrupt_mask1, &up->regs->w.imr1);
262         clear_bit(SAB82532_ALLS, &up->irqflags);
263
264         /* Stuff 32 bytes into Transmit FIFO. */
265         clear_bit(SAB82532_XPR, &up->irqflags);
266         for (i = 0; i < up->port.fifosize; i++) {
267                 writeb(xmit->buf[xmit->tail],
268                        &up->regs->w.xfifo[i]);
269                 xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
270                 up->port.icount.tx++;
271                 if (uart_circ_empty(xmit))
272                         break;
273         }
274
275         /* Issue a Transmit Frame command. */
276         sunsab_cec_wait(up);
277         writeb(SAB82532_CMDR_XF, &up->regs->w.cmdr);
278
279         if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
280                 uart_write_wakeup(&up->port);
281
282         if (uart_circ_empty(xmit))
283                 sunsab_stop_tx(&up->port);
284 }
285
286 static void check_status(struct uart_sunsab_port *up,
287                          union sab82532_irq_status *stat)
288 {
289         if (stat->sreg.isr0 & SAB82532_ISR0_CDSC)
290                 uart_handle_dcd_change(&up->port,
291                                        !(readb(&up->regs->r.vstr) & SAB82532_VSTR_CD));
292
293         if (stat->sreg.isr1 & SAB82532_ISR1_CSC)
294                 uart_handle_cts_change(&up->port,
295                                        (readb(&up->regs->r.star) & SAB82532_STAR_CTS));
296
297         if ((readb(&up->regs->r.pvr) & up->pvr_dsr_bit) ^ up->dsr) {
298                 up->dsr = (readb(&up->regs->r.pvr) & up->pvr_dsr_bit) ? 0 : 1;
299                 up->port.icount.dsr++;
300         }
301
302         wake_up_interruptible(&up->port.info->delta_msr_wait);
303 }
304
305 static irqreturn_t sunsab_interrupt(int irq, void *dev_id, struct pt_regs *regs)
306 {
307         struct uart_sunsab_port *up = dev_id;
308         struct tty_struct *tty;
309         union sab82532_irq_status status;
310         unsigned long flags;
311
312         spin_lock_irqsave(&up->port.lock, flags);
313
314         status.stat = 0;
315         if (readb(&up->regs->r.gis) & SAB82532_GIS_ISA0)
316                 status.sreg.isr0 = readb(&up->regs->r.isr0);
317         if (readb(&up->regs->r.gis) & SAB82532_GIS_ISA1)
318                 status.sreg.isr1 = readb(&up->regs->r.isr1);
319
320         tty = NULL;
321         if (status.stat) {
322                 if ((status.sreg.isr0 & (SAB82532_ISR0_TCD | SAB82532_ISR0_TIME |
323                                          SAB82532_ISR0_RFO | SAB82532_ISR0_RPF)) ||
324                     (status.sreg.isr1 & SAB82532_ISR1_BRK))
325                         tty = receive_chars(up, &status, regs);
326                 if ((status.sreg.isr0 & SAB82532_ISR0_CDSC) ||
327                     (status.sreg.isr1 & SAB82532_ISR1_CSC))
328                         check_status(up, &status);
329                 if (status.sreg.isr1 & (SAB82532_ISR1_ALLS | SAB82532_ISR1_XPR))
330                         transmit_chars(up, &status);
331         }
332
333         spin_unlock(&up->port.lock);
334
335         if (tty)
336                 tty_flip_buffer_push(tty);
337
338         up++;
339
340         spin_lock(&up->port.lock);
341
342         status.stat = 0;
343         if (readb(&up->regs->r.gis) & SAB82532_GIS_ISB0)
344                 status.sreg.isr0 = readb(&up->regs->r.isr0);
345         if (readb(&up->regs->r.gis) & SAB82532_GIS_ISB1)
346                 status.sreg.isr1 = readb(&up->regs->r.isr1);
347
348         tty = NULL;
349         if (status.stat) {
350                 if ((status.sreg.isr0 & (SAB82532_ISR0_TCD | SAB82532_ISR0_TIME |
351                                          SAB82532_ISR0_RFO | SAB82532_ISR0_RPF)) ||
352                     (status.sreg.isr1 & SAB82532_ISR1_BRK))
353
354                         tty = receive_chars(up, &status, regs);
355                 if ((status.sreg.isr0 & SAB82532_ISR0_CDSC) ||
356                     (status.sreg.isr1 & (SAB82532_ISR1_BRK | SAB82532_ISR1_CSC)))
357                         check_status(up, &status);
358                 if (status.sreg.isr1 & (SAB82532_ISR1_ALLS | SAB82532_ISR1_XPR))
359                         transmit_chars(up, &status);
360         }
361
362         spin_unlock_irqrestore(&up->port.lock, flags);
363
364         if (tty)
365                 tty_flip_buffer_push(tty);
366
367         return IRQ_HANDLED;
368 }
369
370 /* port->lock is not held.  */
371 static unsigned int sunsab_tx_empty(struct uart_port *port)
372 {
373         struct uart_sunsab_port *up = (struct uart_sunsab_port *) port;
374         int ret;
375
376         /* Do not need a lock for a state test like this.  */
377         if (test_bit(SAB82532_ALLS, &up->irqflags))
378                 ret = TIOCSER_TEMT;
379         else
380                 ret = 0;
381
382         return ret;
383 }
384
385 /* port->lock held by caller.  */
386 static void sunsab_set_mctrl(struct uart_port *port, unsigned int mctrl)
387 {
388         struct uart_sunsab_port *up = (struct uart_sunsab_port *) port;
389
390         if (mctrl & TIOCM_RTS) {
391                 up->cached_mode &= ~SAB82532_MODE_FRTS;
392                 up->cached_mode |= SAB82532_MODE_RTS;
393         } else {
394                 up->cached_mode |= (SAB82532_MODE_FRTS |
395                                     SAB82532_MODE_RTS);
396         }
397         if (mctrl & TIOCM_DTR) {
398                 up->cached_pvr &= ~(up->pvr_dtr_bit);
399         } else {
400                 up->cached_pvr |= up->pvr_dtr_bit;
401         }
402
403         set_bit(SAB82532_REGS_PENDING, &up->irqflags);
404         if (test_bit(SAB82532_XPR, &up->irqflags))
405                 sunsab_tx_idle(up);
406 }
407
408 /* port->lock is held by caller and interrupts are disabled.  */
409 static unsigned int sunsab_get_mctrl(struct uart_port *port)
410 {
411         struct uart_sunsab_port *up = (struct uart_sunsab_port *) port;
412         unsigned char val;
413         unsigned int result;
414
415         result = 0;
416
417         val = readb(&up->regs->r.pvr);
418         result |= (val & up->pvr_dsr_bit) ? 0 : TIOCM_DSR;
419
420         val = readb(&up->regs->r.vstr);
421         result |= (val & SAB82532_VSTR_CD) ? 0 : TIOCM_CAR;
422
423         val = readb(&up->regs->r.star);
424         result |= (val & SAB82532_STAR_CTS) ? TIOCM_CTS : 0;
425
426         return result;
427 }
428
429 /* port->lock held by caller.  */
430 static void sunsab_stop_tx(struct uart_port *port)
431 {
432         struct uart_sunsab_port *up = (struct uart_sunsab_port *) port;
433
434         up->interrupt_mask1 |= SAB82532_IMR1_XPR;
435         writeb(up->interrupt_mask1, &up->regs->w.imr1);
436 }
437
438 /* port->lock held by caller.  */
439 static void sunsab_tx_idle(struct uart_sunsab_port *up)
440 {
441         if (test_bit(SAB82532_REGS_PENDING, &up->irqflags)) {
442                 u8 tmp;
443
444                 clear_bit(SAB82532_REGS_PENDING, &up->irqflags);
445                 writeb(up->cached_mode, &up->regs->rw.mode);
446                 writeb(up->cached_pvr, &up->regs->rw.pvr);
447                 writeb(up->cached_dafo, &up->regs->w.dafo);
448
449                 writeb(up->cached_ebrg & 0xff, &up->regs->w.bgr);
450                 tmp = readb(&up->regs->rw.ccr2);
451                 tmp &= ~0xc0;
452                 tmp |= (up->cached_ebrg >> 2) & 0xc0;
453                 writeb(tmp, &up->regs->rw.ccr2);
454         }
455 }
456
457 /* port->lock held by caller.  */
458 static void sunsab_start_tx(struct uart_port *port)
459 {
460         struct uart_sunsab_port *up = (struct uart_sunsab_port *) port;
461         struct circ_buf *xmit = &up->port.info->xmit;
462         int i;
463
464         up->interrupt_mask1 &= ~(SAB82532_IMR1_ALLS|SAB82532_IMR1_XPR);
465         writeb(up->interrupt_mask1, &up->regs->w.imr1);
466         
467         if (!test_bit(SAB82532_XPR, &up->irqflags))
468                 return;
469
470         clear_bit(SAB82532_ALLS, &up->irqflags);
471         clear_bit(SAB82532_XPR, &up->irqflags);
472
473         for (i = 0; i < up->port.fifosize; i++) {
474                 writeb(xmit->buf[xmit->tail],
475                        &up->regs->w.xfifo[i]);
476                 xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
477                 up->port.icount.tx++;
478                 if (uart_circ_empty(xmit))
479                         break;
480         }
481
482         /* Issue a Transmit Frame command.  */
483         sunsab_cec_wait(up);
484         writeb(SAB82532_CMDR_XF, &up->regs->w.cmdr);
485 }
486
487 /* port->lock is not held.  */
488 static void sunsab_send_xchar(struct uart_port *port, char ch)
489 {
490         struct uart_sunsab_port *up = (struct uart_sunsab_port *) port;
491         unsigned long flags;
492
493         spin_lock_irqsave(&up->port.lock, flags);
494
495         sunsab_tec_wait(up);
496         writeb(ch, &up->regs->w.tic);
497
498         spin_unlock_irqrestore(&up->port.lock, flags);
499 }
500
501 /* port->lock held by caller.  */
502 static void sunsab_stop_rx(struct uart_port *port)
503 {
504         struct uart_sunsab_port *up = (struct uart_sunsab_port *) port;
505
506         up->interrupt_mask0 |= SAB82532_ISR0_TCD;
507         writeb(up->interrupt_mask1, &up->regs->w.imr0);
508 }
509
510 /* port->lock held by caller.  */
511 static void sunsab_enable_ms(struct uart_port *port)
512 {
513         /* For now we always receive these interrupts.  */
514 }
515
516 /* port->lock is not held.  */
517 static void sunsab_break_ctl(struct uart_port *port, int break_state)
518 {
519         struct uart_sunsab_port *up = (struct uart_sunsab_port *) port;
520         unsigned long flags;
521         unsigned char val;
522
523         spin_lock_irqsave(&up->port.lock, flags);
524
525         val = up->cached_dafo;
526         if (break_state)
527                 val |= SAB82532_DAFO_XBRK;
528         else
529                 val &= ~SAB82532_DAFO_XBRK;
530         up->cached_dafo = val;
531
532         set_bit(SAB82532_REGS_PENDING, &up->irqflags);
533         if (test_bit(SAB82532_XPR, &up->irqflags))
534                 sunsab_tx_idle(up);
535
536         spin_unlock_irqrestore(&up->port.lock, flags);
537 }
538
539 /* port->lock is not held.  */
540 static int sunsab_startup(struct uart_port *port)
541 {
542         struct uart_sunsab_port *up = (struct uart_sunsab_port *) port;
543         unsigned long flags;
544         unsigned char tmp;
545
546         spin_lock_irqsave(&up->port.lock, flags);
547
548         /*
549          * Wait for any commands or immediate characters
550          */
551         sunsab_cec_wait(up);
552         sunsab_tec_wait(up);
553
554         /*
555          * Clear the FIFO buffers.
556          */
557         writeb(SAB82532_CMDR_RRES, &up->regs->w.cmdr);
558         sunsab_cec_wait(up);
559         writeb(SAB82532_CMDR_XRES, &up->regs->w.cmdr);
560
561         /*
562          * Clear the interrupt registers.
563          */
564         (void) readb(&up->regs->r.isr0);
565         (void) readb(&up->regs->r.isr1);
566
567         /*
568          * Now, initialize the UART 
569          */
570         writeb(0, &up->regs->w.ccr0);                           /* power-down */
571         writeb(SAB82532_CCR0_MCE | SAB82532_CCR0_SC_NRZ |
572                SAB82532_CCR0_SM_ASYNC, &up->regs->w.ccr0);
573         writeb(SAB82532_CCR1_ODS | SAB82532_CCR1_BCR | 7, &up->regs->w.ccr1);
574         writeb(SAB82532_CCR2_BDF | SAB82532_CCR2_SSEL |
575                SAB82532_CCR2_TOE, &up->regs->w.ccr2);
576         writeb(0, &up->regs->w.ccr3);
577         writeb(SAB82532_CCR4_MCK4 | SAB82532_CCR4_EBRG, &up->regs->w.ccr4);
578         up->cached_mode = (SAB82532_MODE_RTS | SAB82532_MODE_FCTS |
579                            SAB82532_MODE_RAC);
580         writeb(up->cached_mode, &up->regs->w.mode);
581         writeb(SAB82532_RFC_DPS|SAB82532_RFC_RFTH_32, &up->regs->w.rfc);
582         
583         tmp = readb(&up->regs->rw.ccr0);
584         tmp |= SAB82532_CCR0_PU;        /* power-up */
585         writeb(tmp, &up->regs->rw.ccr0);
586
587         /*
588          * Finally, enable interrupts
589          */
590         up->interrupt_mask0 = (SAB82532_IMR0_PERR | SAB82532_IMR0_FERR |
591                                SAB82532_IMR0_PLLA);
592         writeb(up->interrupt_mask0, &up->regs->w.imr0);
593         up->interrupt_mask1 = (SAB82532_IMR1_BRKT | SAB82532_IMR1_ALLS |
594                                SAB82532_IMR1_XOFF | SAB82532_IMR1_TIN |
595                                SAB82532_IMR1_CSC | SAB82532_IMR1_XON |
596                                SAB82532_IMR1_XPR);
597         writeb(up->interrupt_mask1, &up->regs->w.imr1);
598         set_bit(SAB82532_ALLS, &up->irqflags);
599         set_bit(SAB82532_XPR, &up->irqflags);
600
601         spin_unlock_irqrestore(&up->port.lock, flags);
602
603         return 0;
604 }
605
606 /* port->lock is not held.  */
607 static void sunsab_shutdown(struct uart_port *port)
608 {
609         struct uart_sunsab_port *up = (struct uart_sunsab_port *) port;
610         unsigned long flags;
611
612         spin_lock_irqsave(&up->port.lock, flags);
613
614         /* Disable Interrupts */
615         up->interrupt_mask0 = 0xff;
616         writeb(up->interrupt_mask0, &up->regs->w.imr0);
617         up->interrupt_mask1 = 0xff;
618         writeb(up->interrupt_mask1, &up->regs->w.imr1);
619
620         /* Disable break condition */
621         up->cached_dafo = readb(&up->regs->rw.dafo);
622         up->cached_dafo &= ~SAB82532_DAFO_XBRK;
623         writeb(up->cached_dafo, &up->regs->rw.dafo);
624
625         /* Disable Receiver */  
626         up->cached_mode &= ~SAB82532_MODE_RAC;
627         writeb(up->cached_mode, &up->regs->rw.mode);
628
629         /*
630          * XXX FIXME
631          *
632          * If the chip is powered down here the system hangs/crashes during
633          * reboot or shutdown.  This needs to be investigated further,
634          * similar behaviour occurs in 2.4 when the driver is configured
635          * as a module only.  One hint may be that data is sometimes
636          * transmitted at 9600 baud during shutdown (regardless of the
637          * speed the chip was configured for when the port was open).
638          */
639 #if 0
640         /* Power Down */        
641         tmp = readb(&up->regs->rw.ccr0);
642         tmp &= ~SAB82532_CCR0_PU;
643         writeb(tmp, &up->regs->rw.ccr0);
644 #endif
645
646         spin_unlock_irqrestore(&up->port.lock, flags);
647 }
648
649 /*
650  * This is used to figure out the divisor speeds.
651  *
652  * The formula is:    Baud = SAB_BASE_BAUD / ((N + 1) * (1 << M)),
653  *
654  * with               0 <= N < 64 and 0 <= M < 16
655  */
656
657 static void calc_ebrg(int baud, int *n_ret, int *m_ret)
658 {
659         int     n, m;
660
661         if (baud == 0) {
662                 *n_ret = 0;
663                 *m_ret = 0;
664                 return;
665         }
666      
667         /*
668          * We scale numbers by 10 so that we get better accuracy
669          * without having to use floating point.  Here we increment m
670          * until n is within the valid range.
671          */
672         n = (SAB_BASE_BAUD * 10) / baud;
673         m = 0;
674         while (n >= 640) {
675                 n = n / 2;
676                 m++;
677         }
678         n = (n+5) / 10;
679         /*
680          * We try very hard to avoid speeds with M == 0 since they may
681          * not work correctly for XTAL frequences above 10 MHz.
682          */
683         if ((m == 0) && ((n & 1) == 0)) {
684                 n = n / 2;
685                 m++;
686         }
687         *n_ret = n - 1;
688         *m_ret = m;
689 }
690
691 /* Internal routine, port->lock is held and local interrupts are disabled.  */
692 static void sunsab_convert_to_sab(struct uart_sunsab_port *up, unsigned int cflag,
693                                   unsigned int iflag, unsigned int baud,
694                                   unsigned int quot)
695 {
696         unsigned char dafo;
697         int bits, n, m;
698
699         /* Byte size and parity */
700         switch (cflag & CSIZE) {
701               case CS5: dafo = SAB82532_DAFO_CHL5; bits = 7; break;
702               case CS6: dafo = SAB82532_DAFO_CHL6; bits = 8; break;
703               case CS7: dafo = SAB82532_DAFO_CHL7; bits = 9; break;
704               case CS8: dafo = SAB82532_DAFO_CHL8; bits = 10; break;
705               /* Never happens, but GCC is too dumb to figure it out */
706               default:  dafo = SAB82532_DAFO_CHL5; bits = 7; break;
707         }
708
709         if (cflag & CSTOPB) {
710                 dafo |= SAB82532_DAFO_STOP;
711                 bits++;
712         }
713
714         if (cflag & PARENB) {
715                 dafo |= SAB82532_DAFO_PARE;
716                 bits++;
717         }
718
719         if (cflag & PARODD) {
720                 dafo |= SAB82532_DAFO_PAR_ODD;
721         } else {
722                 dafo |= SAB82532_DAFO_PAR_EVEN;
723         }
724         up->cached_dafo = dafo;
725
726         calc_ebrg(baud, &n, &m);
727
728         up->cached_ebrg = n | (m << 6);
729
730         up->tec_timeout = (10 * 1000000) / baud;
731         up->cec_timeout = up->tec_timeout >> 2;
732
733         /* CTS flow control flags */
734         /* We encode read_status_mask and ignore_status_mask like so:
735          *
736          * ---------------------
737          * | ... | ISR1 | ISR0 |
738          * ---------------------
739          *  ..    15   8 7    0
740          */
741
742         up->port.read_status_mask = (SAB82532_ISR0_TCD | SAB82532_ISR0_TIME |
743                                      SAB82532_ISR0_RFO | SAB82532_ISR0_RPF |
744                                      SAB82532_ISR0_CDSC);
745         up->port.read_status_mask |= (SAB82532_ISR1_CSC |
746                                       SAB82532_ISR1_ALLS |
747                                       SAB82532_ISR1_XPR) << 8;
748         if (iflag & INPCK)
749                 up->port.read_status_mask |= (SAB82532_ISR0_PERR |
750                                               SAB82532_ISR0_FERR);
751         if (iflag & (BRKINT | PARMRK))
752                 up->port.read_status_mask |= (SAB82532_ISR1_BRK << 8);
753
754         /*
755          * Characteres to ignore
756          */
757         up->port.ignore_status_mask = 0;
758         if (iflag & IGNPAR)
759                 up->port.ignore_status_mask |= (SAB82532_ISR0_PERR |
760                                                 SAB82532_ISR0_FERR);
761         if (iflag & IGNBRK) {
762                 up->port.ignore_status_mask |= (SAB82532_ISR1_BRK << 8);
763                 /*
764                  * If we're ignoring parity and break indicators,
765                  * ignore overruns too (for real raw support).
766                  */
767                 if (iflag & IGNPAR)
768                         up->port.ignore_status_mask |= SAB82532_ISR0_RFO;
769         }
770
771         /*
772          * ignore all characters if CREAD is not set
773          */
774         if ((cflag & CREAD) == 0)
775                 up->port.ignore_status_mask |= (SAB82532_ISR0_RPF |
776                                                 SAB82532_ISR0_TCD);
777
778         uart_update_timeout(&up->port, cflag,
779                             (up->port.uartclk / (16 * quot)));
780
781         /* Now schedule a register update when the chip's
782          * transmitter is idle.
783          */
784         up->cached_mode |= SAB82532_MODE_RAC;
785         set_bit(SAB82532_REGS_PENDING, &up->irqflags);
786         if (test_bit(SAB82532_XPR, &up->irqflags))
787                 sunsab_tx_idle(up);
788 }
789
790 /* port->lock is not held.  */
791 static void sunsab_set_termios(struct uart_port *port, struct termios *termios,
792                                struct termios *old)
793 {
794         struct uart_sunsab_port *up = (struct uart_sunsab_port *) port;
795         unsigned long flags;
796         unsigned int baud = uart_get_baud_rate(port, termios, old, 0, 4000000);
797         unsigned int quot = uart_get_divisor(port, baud);
798
799         spin_lock_irqsave(&up->port.lock, flags);
800         sunsab_convert_to_sab(up, termios->c_cflag, termios->c_iflag, baud, quot);
801         spin_unlock_irqrestore(&up->port.lock, flags);
802 }
803
804 static const char *sunsab_type(struct uart_port *port)
805 {
806         struct uart_sunsab_port *up = (void *)port;
807         static char buf[36];
808         
809         sprintf(buf, "SAB82532 %s", sab82532_version[up->type]);
810         return buf;
811 }
812
813 static void sunsab_release_port(struct uart_port *port)
814 {
815 }
816
817 static int sunsab_request_port(struct uart_port *port)
818 {
819         return 0;
820 }
821
822 static void sunsab_config_port(struct uart_port *port, int flags)
823 {
824 }
825
826 static int sunsab_verify_port(struct uart_port *port, struct serial_struct *ser)
827 {
828         return -EINVAL;
829 }
830
831 static struct uart_ops sunsab_pops = {
832         .tx_empty       = sunsab_tx_empty,
833         .set_mctrl      = sunsab_set_mctrl,
834         .get_mctrl      = sunsab_get_mctrl,
835         .stop_tx        = sunsab_stop_tx,
836         .start_tx       = sunsab_start_tx,
837         .send_xchar     = sunsab_send_xchar,
838         .stop_rx        = sunsab_stop_rx,
839         .enable_ms      = sunsab_enable_ms,
840         .break_ctl      = sunsab_break_ctl,
841         .startup        = sunsab_startup,
842         .shutdown       = sunsab_shutdown,
843         .set_termios    = sunsab_set_termios,
844         .type           = sunsab_type,
845         .release_port   = sunsab_release_port,
846         .request_port   = sunsab_request_port,
847         .config_port    = sunsab_config_port,
848         .verify_port    = sunsab_verify_port,
849 };
850
851 static struct uart_driver sunsab_reg = {
852         .owner                  = THIS_MODULE,
853         .driver_name            = "serial",
854         .dev_name               = "ttyS",
855         .major                  = TTY_MAJOR,
856 };
857
858 static struct uart_sunsab_port *sunsab_ports;
859 static int num_channels;
860
861 #ifdef CONFIG_SERIAL_SUNSAB_CONSOLE
862
863 static void sunsab_console_putchar(struct uart_port *port, int c)
864 {
865         struct uart_sunsab_port *up = (struct uart_sunsab_port *)port;
866         unsigned long flags;
867
868         spin_lock_irqsave(&up->port.lock, flags);
869
870         sunsab_tec_wait(up);
871         writeb(c, &up->regs->w.tic);
872
873         spin_unlock_irqrestore(&up->port.lock, flags);
874 }
875
876 static void sunsab_console_write(struct console *con, const char *s, unsigned n)
877 {
878         struct uart_sunsab_port *up = &sunsab_ports[con->index];
879
880         uart_console_write(&up->port, s, n, sunsab_console_putchar);
881         sunsab_tec_wait(up);
882 }
883
884 static int sunsab_console_setup(struct console *con, char *options)
885 {
886         struct uart_sunsab_port *up = &sunsab_ports[con->index];
887         unsigned long flags;
888         unsigned int baud, quot;
889
890         printk("Console: ttyS%d (SAB82532)\n",
891                (sunsab_reg.minor - 64) + con->index);
892
893         sunserial_console_termios(con);
894
895         switch (con->cflag & CBAUD) {
896         case B150: baud = 150; break;
897         case B300: baud = 300; break;
898         case B600: baud = 600; break;
899         case B1200: baud = 1200; break;
900         case B2400: baud = 2400; break;
901         case B4800: baud = 4800; break;
902         default: case B9600: baud = 9600; break;
903         case B19200: baud = 19200; break;
904         case B38400: baud = 38400; break;
905         case B57600: baud = 57600; break;
906         case B115200: baud = 115200; break;
907         case B230400: baud = 230400; break;
908         case B460800: baud = 460800; break;
909         };
910
911         /*
912          * Temporary fix.
913          */
914         spin_lock_init(&up->port.lock);
915
916         /*
917          * Initialize the hardware
918          */
919         sunsab_startup(&up->port);
920
921         spin_lock_irqsave(&up->port.lock, flags);
922
923         /*
924          * Finally, enable interrupts
925          */
926         up->interrupt_mask0 = SAB82532_IMR0_PERR | SAB82532_IMR0_FERR |
927                                 SAB82532_IMR0_PLLA | SAB82532_IMR0_CDSC;
928         writeb(up->interrupt_mask0, &up->regs->w.imr0);
929         up->interrupt_mask1 = SAB82532_IMR1_BRKT | SAB82532_IMR1_ALLS |
930                                 SAB82532_IMR1_XOFF | SAB82532_IMR1_TIN |
931                                 SAB82532_IMR1_CSC | SAB82532_IMR1_XON |
932                                 SAB82532_IMR1_XPR;
933         writeb(up->interrupt_mask1, &up->regs->w.imr1);
934
935         quot = uart_get_divisor(&up->port, baud);
936         sunsab_convert_to_sab(up, con->cflag, 0, baud, quot);
937         sunsab_set_mctrl(&up->port, TIOCM_DTR | TIOCM_RTS);
938
939         spin_unlock_irqrestore(&up->port.lock, flags);
940         
941         return 0;
942 }
943
944 static struct console sunsab_console = {
945         .name   =       "ttyS",
946         .write  =       sunsab_console_write,
947         .device =       uart_console_device,
948         .setup  =       sunsab_console_setup,
949         .flags  =       CON_PRINTBUFFER,
950         .index  =       -1,
951         .data   =       &sunsab_reg,
952 };
953
954 static inline struct console *SUNSAB_CONSOLE(void)
955 {
956         int i;
957
958         if (con_is_present())
959                 return NULL;
960
961         for (i = 0; i < num_channels; i++) {
962                 int this_minor = sunsab_reg.minor + i;
963
964                 if ((this_minor - 64) == (serial_console - 1))
965                         break;
966         }
967         if (i == num_channels)
968                 return NULL;
969
970         sunsab_console.index = i;
971
972         return &sunsab_console;
973 }
974 #else
975 #define SUNSAB_CONSOLE()        (NULL)
976 #define sunsab_console_init()   do { } while (0)
977 #endif
978
979 static void __init for_each_sab_edev(void (*callback)(struct linux_ebus_device *, void *), void *arg)
980 {
981         struct linux_ebus *ebus;
982         struct linux_ebus_device *edev = NULL;
983
984         for_each_ebus(ebus) {
985                 for_each_ebusdev(edev, ebus) {
986                         if (!strcmp(edev->prom_node->name, "se")) {
987                                 callback(edev, arg);
988                                 continue;
989                         } else if (!strcmp(edev->prom_node->name, "serial")) {
990                                 char *compat;
991                                 int clen;
992
993                                 /* On RIO this can be an SE, check it.  We could
994                                  * just check ebus->is_rio, but this is more portable.
995                                  */
996                                 compat = of_get_property(edev->prom_node,
997                                                          "compatible", &clen);
998                                 if (compat && clen > 0) {
999                                         if (strncmp(compat, "sab82532", 8) == 0) {
1000                                                 callback(edev, arg);
1001                                                 continue;
1002                                         }
1003                                 }
1004                         }
1005                 }
1006         }
1007 }
1008
1009 static void __init sab_count_callback(struct linux_ebus_device *edev, void *arg)
1010 {
1011         int *count_p = arg;
1012
1013         (*count_p)++;
1014 }
1015
1016 static void __init sab_attach_callback(struct linux_ebus_device *edev, void *arg)
1017 {
1018         int *instance_p = arg;
1019         struct uart_sunsab_port *up;
1020         unsigned long regs, offset;
1021         int i;
1022
1023         /* Note: ports are located in reverse order */
1024         regs = edev->resource[0].start;
1025         offset = sizeof(union sab82532_async_regs);
1026         for (i = 0; i < 2; i++) {
1027                 up = &sunsab_ports[(*instance_p * 2) + 1 - i];
1028
1029                 memset(up, 0, sizeof(*up));
1030                 up->regs = ioremap(regs + offset, sizeof(union sab82532_async_regs));
1031                 up->port.irq = edev->irqs[0];
1032                 up->port.fifosize = SAB82532_XMIT_FIFO_SIZE;
1033                 up->port.mapbase = (unsigned long)up->regs;
1034                 up->port.iotype = UPIO_MEM;
1035
1036                 writeb(SAB82532_IPC_IC_ACT_LOW, &up->regs->w.ipc);
1037
1038                 offset -= sizeof(union sab82532_async_regs);
1039         }
1040         
1041         (*instance_p)++;
1042 }
1043
1044 static int __init probe_for_sabs(void)
1045 {
1046         int this_sab = 0;
1047
1048         /* Find device instances.  */
1049         for_each_sab_edev(&sab_count_callback, &this_sab);
1050         if (!this_sab)
1051                 return -ENODEV;
1052
1053         /* Allocate tables.  */
1054         sunsab_ports = kmalloc(sizeof(struct uart_sunsab_port) * this_sab * 2,
1055                                GFP_KERNEL);
1056         if (!sunsab_ports)
1057                 return -ENOMEM;
1058
1059         num_channels = this_sab * 2;
1060
1061         this_sab = 0;
1062         for_each_sab_edev(&sab_attach_callback, &this_sab);
1063         return 0;
1064 }
1065
1066 static void __init sunsab_init_hw(void)
1067 {
1068         int i;
1069
1070         for (i = 0; i < num_channels; i++) {
1071                 struct uart_sunsab_port *up = &sunsab_ports[i];
1072
1073                 up->port.line = i;
1074                 up->port.ops = &sunsab_pops;
1075                 up->port.type = PORT_SUNSAB;
1076                 up->port.uartclk = SAB_BASE_BAUD;
1077
1078                 up->type = readb(&up->regs->r.vstr) & 0x0f;
1079                 writeb(~((1 << 1) | (1 << 2) | (1 << 4)), &up->regs->w.pcr);
1080                 writeb(0xff, &up->regs->w.pim);
1081                 if (up->port.line == 0) {
1082                         up->pvr_dsr_bit = (1 << 0);
1083                         up->pvr_dtr_bit = (1 << 1);
1084                 } else {
1085                         up->pvr_dsr_bit = (1 << 3);
1086                         up->pvr_dtr_bit = (1 << 2);
1087                 }
1088                 up->cached_pvr = (1 << 1) | (1 << 2) | (1 << 4);
1089                 writeb(up->cached_pvr, &up->regs->w.pvr);
1090                 up->cached_mode = readb(&up->regs->rw.mode);
1091                 up->cached_mode |= SAB82532_MODE_FRTS;
1092                 writeb(up->cached_mode, &up->regs->rw.mode);
1093                 up->cached_mode |= SAB82532_MODE_RTS;
1094                 writeb(up->cached_mode, &up->regs->rw.mode);
1095
1096                 up->tec_timeout = SAB82532_MAX_TEC_TIMEOUT;
1097                 up->cec_timeout = SAB82532_MAX_CEC_TIMEOUT;
1098
1099                 if (!(up->port.line & 0x01)) {
1100                         if (request_irq(up->port.irq, sunsab_interrupt,
1101                                         SA_SHIRQ, "serial(sab82532)", up)) {
1102                                 printk("sunsab%d: can't get IRQ %x\n",
1103                                        i, up->port.irq);
1104                                 continue;
1105                         }
1106                 }
1107         }
1108 }
1109
1110 static int __init sunsab_init(void)
1111 {
1112         int ret = probe_for_sabs();
1113         int i;
1114
1115         if (ret < 0)
1116                 return ret;
1117
1118         sunsab_init_hw();
1119
1120         sunsab_reg.minor = sunserial_current_minor;
1121         sunsab_reg.nr = num_channels;
1122
1123         ret = uart_register_driver(&sunsab_reg);
1124         if (ret < 0) {
1125                 int i;
1126
1127                 for (i = 0; i < num_channels; i++) {
1128                         struct uart_sunsab_port *up = &sunsab_ports[i];
1129
1130                         if (!(up->port.line & 0x01))
1131                                 free_irq(up->port.irq, up);
1132                         iounmap(up->regs);
1133                 }
1134                 kfree(sunsab_ports);
1135                 sunsab_ports = NULL;
1136
1137                 return ret;
1138         }
1139
1140         sunsab_reg.tty_driver->name_base = sunsab_reg.minor - 64;
1141
1142         sunsab_reg.cons = SUNSAB_CONSOLE();
1143
1144         sunserial_current_minor += num_channels;
1145         
1146         for (i = 0; i < num_channels; i++) {
1147                 struct uart_sunsab_port *up = &sunsab_ports[i];
1148
1149                 uart_add_one_port(&sunsab_reg, &up->port);
1150         }
1151
1152         return 0;
1153 }
1154
1155 static void __exit sunsab_exit(void)
1156 {
1157         int i;
1158
1159         for (i = 0; i < num_channels; i++) {
1160                 struct uart_sunsab_port *up = &sunsab_ports[i];
1161
1162                 uart_remove_one_port(&sunsab_reg, &up->port);
1163
1164                 if (!(up->port.line & 0x01))
1165                         free_irq(up->port.irq, up);
1166                 iounmap(up->regs);
1167         }
1168
1169         sunserial_current_minor -= num_channels;
1170         uart_unregister_driver(&sunsab_reg);
1171
1172         kfree(sunsab_ports);
1173         sunsab_ports = NULL;
1174 }
1175
1176 module_init(sunsab_init);
1177 module_exit(sunsab_exit);
1178
1179 MODULE_AUTHOR("Eddie C. Dost and David S. Miller");
1180 MODULE_DESCRIPTION("Sun SAB82532 serial port driver");
1181 MODULE_LICENSE("GPL");