Merge ../scsi-misc-2.6
[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, 2006  David S. Miller (davem@davemloft.net)
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@davemloft.net>
16  */
17
18 #include <linux/module.h>
19 #include <linux/kernel.h>
20 #include <linux/sched.h>
21 #include <linux/errno.h>
22 #include <linux/tty.h>
23 #include <linux/tty_flip.h>
24 #include <linux/major.h>
25 #include <linux/string.h>
26 #include <linux/ptrace.h>
27 #include <linux/ioport.h>
28 #include <linux/circ_buf.h>
29 #include <linux/serial.h>
30 #include <linux/sysrq.h>
31 #include <linux/console.h>
32 #include <linux/spinlock.h>
33 #include <linux/slab.h>
34 #include <linux/delay.h>
35 #include <linux/init.h>
36
37 #include <asm/io.h>
38 #include <asm/irq.h>
39 #include <asm/prom.h>
40 #include <asm/of_device.h>
41
42 #if defined(CONFIG_SERIAL_SUNZILOG_CONSOLE) && defined(CONFIG_MAGIC_SYSRQ)
43 #define SUPPORT_SYSRQ
44 #endif
45
46 #include <linux/serial_core.h>
47
48 #include "suncore.h"
49 #include "sunsab.h"
50
51 struct uart_sunsab_port {
52         struct uart_port                port;           /* Generic UART port    */
53         union sab82532_async_regs       __iomem *regs;  /* Chip registers       */
54         unsigned long                   irqflags;       /* IRQ state flags      */
55         int                             dsr;            /* Current DSR state    */
56         unsigned int                    cec_timeout;    /* Chip poll timeout... */
57         unsigned int                    tec_timeout;    /* likewise             */
58         unsigned char                   interrupt_mask0;/* ISR0 masking         */
59         unsigned char                   interrupt_mask1;/* ISR1 masking         */
60         unsigned char                   pvr_dtr_bit;    /* Which PVR bit is DTR */
61         unsigned char                   pvr_dsr_bit;    /* Which PVR bit is DSR */
62         int                             type;           /* SAB82532 version     */
63
64         /* Setting configuration bits while the transmitter is active
65          * can cause garbage characters to get emitted by the chip.
66          * Therefore, we cache such writes here and do the real register
67          * write the next time the transmitter becomes idle.
68          */
69         unsigned int                    cached_ebrg;
70         unsigned char                   cached_mode;
71         unsigned char                   cached_pvr;
72         unsigned char                   cached_dafo;
73 };
74
75 /*
76  * This assumes you have a 29.4912 MHz clock for your UART.
77  */
78 #define SAB_BASE_BAUD ( 29491200 / 16 )
79
80 static char *sab82532_version[16] = {
81         "V1.0", "V2.0", "V3.2", "V(0x03)",
82         "V(0x04)", "V(0x05)", "V(0x06)", "V(0x07)",
83         "V(0x08)", "V(0x09)", "V(0x0a)", "V(0x0b)",
84         "V(0x0c)", "V(0x0d)", "V(0x0e)", "V(0x0f)"
85 };
86
87 #define SAB82532_MAX_TEC_TIMEOUT 200000 /* 1 character time (at 50 baud) */
88 #define SAB82532_MAX_CEC_TIMEOUT  50000 /* 2.5 TX CLKs (at 50 baud) */
89
90 #define SAB82532_RECV_FIFO_SIZE 32      /* Standard async fifo sizes */
91 #define SAB82532_XMIT_FIFO_SIZE 32
92
93 static __inline__ void sunsab_tec_wait(struct uart_sunsab_port *up)
94 {
95         int timeout = up->tec_timeout;
96
97         while ((readb(&up->regs->r.star) & SAB82532_STAR_TEC) && --timeout)
98                 udelay(1);
99 }
100
101 static __inline__ void sunsab_cec_wait(struct uart_sunsab_port *up)
102 {
103         int timeout = up->cec_timeout;
104
105         while ((readb(&up->regs->r.star) & SAB82532_STAR_CEC) && --timeout)
106                 udelay(1);
107 }
108
109 static struct tty_struct *
110 receive_chars(struct uart_sunsab_port *up,
111               union sab82532_irq_status *stat,
112               struct pt_regs *regs)
113 {
114         struct tty_struct *tty = NULL;
115         unsigned char buf[32];
116         int saw_console_brk = 0;
117         int free_fifo = 0;
118         int count = 0;
119         int i;
120
121         if (up->port.info != NULL)              /* Unopened serial console */
122                 tty = up->port.info->tty;
123
124         /* Read number of BYTES (Character + Status) available. */
125         if (stat->sreg.isr0 & SAB82532_ISR0_RPF) {
126                 count = SAB82532_RECV_FIFO_SIZE;
127                 free_fifo++;
128         }
129
130         if (stat->sreg.isr0 & SAB82532_ISR0_TCD) {
131                 count = readb(&up->regs->r.rbcl) & (SAB82532_RECV_FIFO_SIZE - 1);
132                 free_fifo++;
133         }
134
135         /* Issue a FIFO read command in case we where idle. */
136         if (stat->sreg.isr0 & SAB82532_ISR0_TIME) {
137                 sunsab_cec_wait(up);
138                 writeb(SAB82532_CMDR_RFRD, &up->regs->w.cmdr);
139                 return tty;
140         }
141
142         if (stat->sreg.isr0 & SAB82532_ISR0_RFO)
143                 free_fifo++;
144
145         /* Read the FIFO. */
146         for (i = 0; i < count; i++)
147                 buf[i] = readb(&up->regs->r.rfifo[i]);
148
149         /* Issue Receive Message Complete command. */
150         if (free_fifo) {
151                 sunsab_cec_wait(up);
152                 writeb(SAB82532_CMDR_RMC, &up->regs->w.cmdr);
153         }
154
155         /* Count may be zero for BRK, so we check for it here */
156         if ((stat->sreg.isr1 & SAB82532_ISR1_BRK) &&
157             (up->port.line == up->port.cons->index))
158                 saw_console_brk = 1;
159
160         for (i = 0; i < count; i++) {
161                 unsigned char ch = buf[i], flag;
162
163                 if (tty == NULL) {
164                         uart_handle_sysrq_char(&up->port, ch, regs);
165                         continue;
166                 }
167
168                 flag = TTY_NORMAL;
169                 up->port.icount.rx++;
170
171                 if (unlikely(stat->sreg.isr0 & (SAB82532_ISR0_PERR |
172                                                 SAB82532_ISR0_FERR |
173                                                 SAB82532_ISR0_RFO)) ||
174                     unlikely(stat->sreg.isr1 & SAB82532_ISR1_BRK)) {
175                         /*
176                          * For statistics only
177                          */
178                         if (stat->sreg.isr1 & SAB82532_ISR1_BRK) {
179                                 stat->sreg.isr0 &= ~(SAB82532_ISR0_PERR |
180                                                      SAB82532_ISR0_FERR);
181                                 up->port.icount.brk++;
182                                 /*
183                                  * We do the SysRQ and SAK checking
184                                  * here because otherwise the break
185                                  * may get masked by ignore_status_mask
186                                  * or read_status_mask.
187                                  */
188                                 if (uart_handle_break(&up->port))
189                                         continue;
190                         } else if (stat->sreg.isr0 & SAB82532_ISR0_PERR)
191                                 up->port.icount.parity++;
192                         else if (stat->sreg.isr0 & SAB82532_ISR0_FERR)
193                                 up->port.icount.frame++;
194                         if (stat->sreg.isr0 & SAB82532_ISR0_RFO)
195                                 up->port.icount.overrun++;
196
197                         /*
198                          * Mask off conditions which should be ingored.
199                          */
200                         stat->sreg.isr0 &= (up->port.read_status_mask & 0xff);
201                         stat->sreg.isr1 &= ((up->port.read_status_mask >> 8) & 0xff);
202
203                         if (stat->sreg.isr1 & SAB82532_ISR1_BRK) {
204                                 flag = TTY_BREAK;
205                         } else if (stat->sreg.isr0 & SAB82532_ISR0_PERR)
206                                 flag = TTY_PARITY;
207                         else if (stat->sreg.isr0 & SAB82532_ISR0_FERR)
208                                 flag = TTY_FRAME;
209                 }
210
211                 if (uart_handle_sysrq_char(&up->port, ch, regs))
212                         continue;
213
214                 if ((stat->sreg.isr0 & (up->port.ignore_status_mask & 0xff)) == 0 &&
215                     (stat->sreg.isr1 & ((up->port.ignore_status_mask >> 8) & 0xff)) == 0)
216                         tty_insert_flip_char(tty, ch, flag);
217                 if (stat->sreg.isr0 & SAB82532_ISR0_RFO)
218                         tty_insert_flip_char(tty, 0, TTY_OVERRUN);
219         }
220
221         if (saw_console_brk)
222                 sun_do_break();
223
224         return tty;
225 }
226
227 static void sunsab_stop_tx(struct uart_port *);
228 static void sunsab_tx_idle(struct uart_sunsab_port *);
229
230 static void transmit_chars(struct uart_sunsab_port *up,
231                            union sab82532_irq_status *stat)
232 {
233         struct circ_buf *xmit = &up->port.info->xmit;
234         int i;
235
236         if (stat->sreg.isr1 & SAB82532_ISR1_ALLS) {
237                 up->interrupt_mask1 |= SAB82532_IMR1_ALLS;
238                 writeb(up->interrupt_mask1, &up->regs->w.imr1);
239                 set_bit(SAB82532_ALLS, &up->irqflags);
240         }
241
242 #if 0 /* bde@nwlink.com says this check causes problems */
243         if (!(stat->sreg.isr1 & SAB82532_ISR1_XPR))
244                 return;
245 #endif
246
247         if (!(readb(&up->regs->r.star) & SAB82532_STAR_XFW))
248                 return;
249
250         set_bit(SAB82532_XPR, &up->irqflags);
251         sunsab_tx_idle(up);
252
253         if (uart_circ_empty(xmit) || uart_tx_stopped(&up->port)) {
254                 up->interrupt_mask1 |= SAB82532_IMR1_XPR;
255                 writeb(up->interrupt_mask1, &up->regs->w.imr1);
256                 return;
257         }
258
259         up->interrupt_mask1 &= ~(SAB82532_IMR1_ALLS|SAB82532_IMR1_XPR);
260         writeb(up->interrupt_mask1, &up->regs->w.imr1);
261         clear_bit(SAB82532_ALLS, &up->irqflags);
262
263         /* Stuff 32 bytes into Transmit FIFO. */
264         clear_bit(SAB82532_XPR, &up->irqflags);
265         for (i = 0; i < up->port.fifosize; i++) {
266                 writeb(xmit->buf[xmit->tail],
267                        &up->regs->w.xfifo[i]);
268                 xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
269                 up->port.icount.tx++;
270                 if (uart_circ_empty(xmit))
271                         break;
272         }
273
274         /* Issue a Transmit Frame command. */
275         sunsab_cec_wait(up);
276         writeb(SAB82532_CMDR_XF, &up->regs->w.cmdr);
277
278         if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
279                 uart_write_wakeup(&up->port);
280
281         if (uart_circ_empty(xmit))
282                 sunsab_stop_tx(&up->port);
283 }
284
285 static void check_status(struct uart_sunsab_port *up,
286                          union sab82532_irq_status *stat)
287 {
288         if (stat->sreg.isr0 & SAB82532_ISR0_CDSC)
289                 uart_handle_dcd_change(&up->port,
290                                        !(readb(&up->regs->r.vstr) & SAB82532_VSTR_CD));
291
292         if (stat->sreg.isr1 & SAB82532_ISR1_CSC)
293                 uart_handle_cts_change(&up->port,
294                                        (readb(&up->regs->r.star) & SAB82532_STAR_CTS));
295
296         if ((readb(&up->regs->r.pvr) & up->pvr_dsr_bit) ^ up->dsr) {
297                 up->dsr = (readb(&up->regs->r.pvr) & up->pvr_dsr_bit) ? 0 : 1;
298                 up->port.icount.dsr++;
299         }
300
301         wake_up_interruptible(&up->port.info->delta_msr_wait);
302 }
303
304 static irqreturn_t sunsab_interrupt(int irq, void *dev_id, struct pt_regs *regs)
305 {
306         struct uart_sunsab_port *up = dev_id;
307         struct tty_struct *tty;
308         union sab82532_irq_status status;
309         unsigned long flags;
310
311         spin_lock_irqsave(&up->port.lock, flags);
312
313         status.stat = 0;
314         if (readb(&up->regs->r.gis) & SAB82532_GIS_ISA0)
315                 status.sreg.isr0 = readb(&up->regs->r.isr0);
316         if (readb(&up->regs->r.gis) & SAB82532_GIS_ISA1)
317                 status.sreg.isr1 = readb(&up->regs->r.isr1);
318
319         tty = NULL;
320         if (status.stat) {
321                 if ((status.sreg.isr0 & (SAB82532_ISR0_TCD | SAB82532_ISR0_TIME |
322                                          SAB82532_ISR0_RFO | SAB82532_ISR0_RPF)) ||
323                     (status.sreg.isr1 & SAB82532_ISR1_BRK))
324                         tty = receive_chars(up, &status, regs);
325                 if ((status.sreg.isr0 & SAB82532_ISR0_CDSC) ||
326                     (status.sreg.isr1 & SAB82532_ISR1_CSC))
327                         check_status(up, &status);
328                 if (status.sreg.isr1 & (SAB82532_ISR1_ALLS | SAB82532_ISR1_XPR))
329                         transmit_chars(up, &status);
330         }
331
332         spin_unlock(&up->port.lock);
333
334         if (tty)
335                 tty_flip_buffer_push(tty);
336
337         up++;
338
339         spin_lock(&up->port.lock);
340
341         status.stat = 0;
342         if (readb(&up->regs->r.gis) & SAB82532_GIS_ISB0)
343                 status.sreg.isr0 = readb(&up->regs->r.isr0);
344         if (readb(&up->regs->r.gis) & SAB82532_GIS_ISB1)
345                 status.sreg.isr1 = readb(&up->regs->r.isr1);
346
347         tty = NULL;
348         if (status.stat) {
349                 if ((status.sreg.isr0 & (SAB82532_ISR0_TCD | SAB82532_ISR0_TIME |
350                                          SAB82532_ISR0_RFO | SAB82532_ISR0_RPF)) ||
351                     (status.sreg.isr1 & SAB82532_ISR1_BRK))
352
353                         tty = receive_chars(up, &status, regs);
354                 if ((status.sreg.isr0 & SAB82532_ISR0_CDSC) ||
355                     (status.sreg.isr1 & (SAB82532_ISR1_BRK | SAB82532_ISR1_CSC)))
356                         check_status(up, &status);
357                 if (status.sreg.isr1 & (SAB82532_ISR1_ALLS | SAB82532_ISR1_XPR))
358                         transmit_chars(up, &status);
359         }
360
361         spin_unlock_irqrestore(&up->port.lock, flags);
362
363         if (tty)
364                 tty_flip_buffer_push(tty);
365
366         return IRQ_HANDLED;
367 }
368
369 /* port->lock is not held.  */
370 static unsigned int sunsab_tx_empty(struct uart_port *port)
371 {
372         struct uart_sunsab_port *up = (struct uart_sunsab_port *) port;
373         int ret;
374
375         /* Do not need a lock for a state test like this.  */
376         if (test_bit(SAB82532_ALLS, &up->irqflags))
377                 ret = TIOCSER_TEMT;
378         else
379                 ret = 0;
380
381         return ret;
382 }
383
384 /* port->lock held by caller.  */
385 static void sunsab_set_mctrl(struct uart_port *port, unsigned int mctrl)
386 {
387         struct uart_sunsab_port *up = (struct uart_sunsab_port *) port;
388
389         if (mctrl & TIOCM_RTS) {
390                 up->cached_mode &= ~SAB82532_MODE_FRTS;
391                 up->cached_mode |= SAB82532_MODE_RTS;
392         } else {
393                 up->cached_mode |= (SAB82532_MODE_FRTS |
394                                     SAB82532_MODE_RTS);
395         }
396         if (mctrl & TIOCM_DTR) {
397                 up->cached_pvr &= ~(up->pvr_dtr_bit);
398         } else {
399                 up->cached_pvr |= up->pvr_dtr_bit;
400         }
401
402         set_bit(SAB82532_REGS_PENDING, &up->irqflags);
403         if (test_bit(SAB82532_XPR, &up->irqflags))
404                 sunsab_tx_idle(up);
405 }
406
407 /* port->lock is held by caller and interrupts are disabled.  */
408 static unsigned int sunsab_get_mctrl(struct uart_port *port)
409 {
410         struct uart_sunsab_port *up = (struct uart_sunsab_port *) port;
411         unsigned char val;
412         unsigned int result;
413
414         result = 0;
415
416         val = readb(&up->regs->r.pvr);
417         result |= (val & up->pvr_dsr_bit) ? 0 : TIOCM_DSR;
418
419         val = readb(&up->regs->r.vstr);
420         result |= (val & SAB82532_VSTR_CD) ? 0 : TIOCM_CAR;
421
422         val = readb(&up->regs->r.star);
423         result |= (val & SAB82532_STAR_CTS) ? TIOCM_CTS : 0;
424
425         return result;
426 }
427
428 /* port->lock held by caller.  */
429 static void sunsab_stop_tx(struct uart_port *port)
430 {
431         struct uart_sunsab_port *up = (struct uart_sunsab_port *) port;
432
433         up->interrupt_mask1 |= SAB82532_IMR1_XPR;
434         writeb(up->interrupt_mask1, &up->regs->w.imr1);
435 }
436
437 /* port->lock held by caller.  */
438 static void sunsab_tx_idle(struct uart_sunsab_port *up)
439 {
440         if (test_bit(SAB82532_REGS_PENDING, &up->irqflags)) {
441                 u8 tmp;
442
443                 clear_bit(SAB82532_REGS_PENDING, &up->irqflags);
444                 writeb(up->cached_mode, &up->regs->rw.mode);
445                 writeb(up->cached_pvr, &up->regs->rw.pvr);
446                 writeb(up->cached_dafo, &up->regs->w.dafo);
447
448                 writeb(up->cached_ebrg & 0xff, &up->regs->w.bgr);
449                 tmp = readb(&up->regs->rw.ccr2);
450                 tmp &= ~0xc0;
451                 tmp |= (up->cached_ebrg >> 2) & 0xc0;
452                 writeb(tmp, &up->regs->rw.ccr2);
453         }
454 }
455
456 /* port->lock held by caller.  */
457 static void sunsab_start_tx(struct uart_port *port)
458 {
459         struct uart_sunsab_port *up = (struct uart_sunsab_port *) port;
460         struct circ_buf *xmit = &up->port.info->xmit;
461         int i;
462
463         up->interrupt_mask1 &= ~(SAB82532_IMR1_ALLS|SAB82532_IMR1_XPR);
464         writeb(up->interrupt_mask1, &up->regs->w.imr1);
465         
466         if (!test_bit(SAB82532_XPR, &up->irqflags))
467                 return;
468
469         clear_bit(SAB82532_ALLS, &up->irqflags);
470         clear_bit(SAB82532_XPR, &up->irqflags);
471
472         for (i = 0; i < up->port.fifosize; i++) {
473                 writeb(xmit->buf[xmit->tail],
474                        &up->regs->w.xfifo[i]);
475                 xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
476                 up->port.icount.tx++;
477                 if (uart_circ_empty(xmit))
478                         break;
479         }
480
481         /* Issue a Transmit Frame command.  */
482         sunsab_cec_wait(up);
483         writeb(SAB82532_CMDR_XF, &up->regs->w.cmdr);
484 }
485
486 /* port->lock is not held.  */
487 static void sunsab_send_xchar(struct uart_port *port, char ch)
488 {
489         struct uart_sunsab_port *up = (struct uart_sunsab_port *) port;
490         unsigned long flags;
491
492         spin_lock_irqsave(&up->port.lock, flags);
493
494         sunsab_tec_wait(up);
495         writeb(ch, &up->regs->w.tic);
496
497         spin_unlock_irqrestore(&up->port.lock, flags);
498 }
499
500 /* port->lock held by caller.  */
501 static void sunsab_stop_rx(struct uart_port *port)
502 {
503         struct uart_sunsab_port *up = (struct uart_sunsab_port *) port;
504
505         up->interrupt_mask0 |= SAB82532_ISR0_TCD;
506         writeb(up->interrupt_mask1, &up->regs->w.imr0);
507 }
508
509 /* port->lock held by caller.  */
510 static void sunsab_enable_ms(struct uart_port *port)
511 {
512         /* For now we always receive these interrupts.  */
513 }
514
515 /* port->lock is not held.  */
516 static void sunsab_break_ctl(struct uart_port *port, int break_state)
517 {
518         struct uart_sunsab_port *up = (struct uart_sunsab_port *) port;
519         unsigned long flags;
520         unsigned char val;
521
522         spin_lock_irqsave(&up->port.lock, flags);
523
524         val = up->cached_dafo;
525         if (break_state)
526                 val |= SAB82532_DAFO_XBRK;
527         else
528                 val &= ~SAB82532_DAFO_XBRK;
529         up->cached_dafo = val;
530
531         set_bit(SAB82532_REGS_PENDING, &up->irqflags);
532         if (test_bit(SAB82532_XPR, &up->irqflags))
533                 sunsab_tx_idle(up);
534
535         spin_unlock_irqrestore(&up->port.lock, flags);
536 }
537
538 /* port->lock is not held.  */
539 static int sunsab_startup(struct uart_port *port)
540 {
541         struct uart_sunsab_port *up = (struct uart_sunsab_port *) port;
542         unsigned long flags;
543         unsigned char tmp;
544
545         spin_lock_irqsave(&up->port.lock, flags);
546
547         /*
548          * Wait for any commands or immediate characters
549          */
550         sunsab_cec_wait(up);
551         sunsab_tec_wait(up);
552
553         /*
554          * Clear the FIFO buffers.
555          */
556         writeb(SAB82532_CMDR_RRES, &up->regs->w.cmdr);
557         sunsab_cec_wait(up);
558         writeb(SAB82532_CMDR_XRES, &up->regs->w.cmdr);
559
560         /*
561          * Clear the interrupt registers.
562          */
563         (void) readb(&up->regs->r.isr0);
564         (void) readb(&up->regs->r.isr1);
565
566         /*
567          * Now, initialize the UART 
568          */
569         writeb(0, &up->regs->w.ccr0);                           /* power-down */
570         writeb(SAB82532_CCR0_MCE | SAB82532_CCR0_SC_NRZ |
571                SAB82532_CCR0_SM_ASYNC, &up->regs->w.ccr0);
572         writeb(SAB82532_CCR1_ODS | SAB82532_CCR1_BCR | 7, &up->regs->w.ccr1);
573         writeb(SAB82532_CCR2_BDF | SAB82532_CCR2_SSEL |
574                SAB82532_CCR2_TOE, &up->regs->w.ccr2);
575         writeb(0, &up->regs->w.ccr3);
576         writeb(SAB82532_CCR4_MCK4 | SAB82532_CCR4_EBRG, &up->regs->w.ccr4);
577         up->cached_mode = (SAB82532_MODE_RTS | SAB82532_MODE_FCTS |
578                            SAB82532_MODE_RAC);
579         writeb(up->cached_mode, &up->regs->w.mode);
580         writeb(SAB82532_RFC_DPS|SAB82532_RFC_RFTH_32, &up->regs->w.rfc);
581         
582         tmp = readb(&up->regs->rw.ccr0);
583         tmp |= SAB82532_CCR0_PU;        /* power-up */
584         writeb(tmp, &up->regs->rw.ccr0);
585
586         /*
587          * Finally, enable interrupts
588          */
589         up->interrupt_mask0 = (SAB82532_IMR0_PERR | SAB82532_IMR0_FERR |
590                                SAB82532_IMR0_PLLA);
591         writeb(up->interrupt_mask0, &up->regs->w.imr0);
592         up->interrupt_mask1 = (SAB82532_IMR1_BRKT | SAB82532_IMR1_ALLS |
593                                SAB82532_IMR1_XOFF | SAB82532_IMR1_TIN |
594                                SAB82532_IMR1_CSC | SAB82532_IMR1_XON |
595                                SAB82532_IMR1_XPR);
596         writeb(up->interrupt_mask1, &up->regs->w.imr1);
597         set_bit(SAB82532_ALLS, &up->irqflags);
598         set_bit(SAB82532_XPR, &up->irqflags);
599
600         spin_unlock_irqrestore(&up->port.lock, flags);
601
602         return 0;
603 }
604
605 /* port->lock is not held.  */
606 static void sunsab_shutdown(struct uart_port *port)
607 {
608         struct uart_sunsab_port *up = (struct uart_sunsab_port *) port;
609         unsigned long flags;
610
611         spin_lock_irqsave(&up->port.lock, flags);
612
613         /* Disable Interrupts */
614         up->interrupt_mask0 = 0xff;
615         writeb(up->interrupt_mask0, &up->regs->w.imr0);
616         up->interrupt_mask1 = 0xff;
617         writeb(up->interrupt_mask1, &up->regs->w.imr1);
618
619         /* Disable break condition */
620         up->cached_dafo = readb(&up->regs->rw.dafo);
621         up->cached_dafo &= ~SAB82532_DAFO_XBRK;
622         writeb(up->cached_dafo, &up->regs->rw.dafo);
623
624         /* Disable Receiver */  
625         up->cached_mode &= ~SAB82532_MODE_RAC;
626         writeb(up->cached_mode, &up->regs->rw.mode);
627
628         /*
629          * XXX FIXME
630          *
631          * If the chip is powered down here the system hangs/crashes during
632          * reboot or shutdown.  This needs to be investigated further,
633          * similar behaviour occurs in 2.4 when the driver is configured
634          * as a module only.  One hint may be that data is sometimes
635          * transmitted at 9600 baud during shutdown (regardless of the
636          * speed the chip was configured for when the port was open).
637          */
638 #if 0
639         /* Power Down */        
640         tmp = readb(&up->regs->rw.ccr0);
641         tmp &= ~SAB82532_CCR0_PU;
642         writeb(tmp, &up->regs->rw.ccr0);
643 #endif
644
645         spin_unlock_irqrestore(&up->port.lock, flags);
646 }
647
648 /*
649  * This is used to figure out the divisor speeds.
650  *
651  * The formula is:    Baud = SAB_BASE_BAUD / ((N + 1) * (1 << M)),
652  *
653  * with               0 <= N < 64 and 0 <= M < 16
654  */
655
656 static void calc_ebrg(int baud, int *n_ret, int *m_ret)
657 {
658         int     n, m;
659
660         if (baud == 0) {
661                 *n_ret = 0;
662                 *m_ret = 0;
663                 return;
664         }
665      
666         /*
667          * We scale numbers by 10 so that we get better accuracy
668          * without having to use floating point.  Here we increment m
669          * until n is within the valid range.
670          */
671         n = (SAB_BASE_BAUD * 10) / baud;
672         m = 0;
673         while (n >= 640) {
674                 n = n / 2;
675                 m++;
676         }
677         n = (n+5) / 10;
678         /*
679          * We try very hard to avoid speeds with M == 0 since they may
680          * not work correctly for XTAL frequences above 10 MHz.
681          */
682         if ((m == 0) && ((n & 1) == 0)) {
683                 n = n / 2;
684                 m++;
685         }
686         *n_ret = n - 1;
687         *m_ret = m;
688 }
689
690 /* Internal routine, port->lock is held and local interrupts are disabled.  */
691 static void sunsab_convert_to_sab(struct uart_sunsab_port *up, unsigned int cflag,
692                                   unsigned int iflag, unsigned int baud,
693                                   unsigned int quot)
694 {
695         unsigned char dafo;
696         int bits, n, m;
697
698         /* Byte size and parity */
699         switch (cflag & CSIZE) {
700               case CS5: dafo = SAB82532_DAFO_CHL5; bits = 7; break;
701               case CS6: dafo = SAB82532_DAFO_CHL6; bits = 8; break;
702               case CS7: dafo = SAB82532_DAFO_CHL7; bits = 9; break;
703               case CS8: dafo = SAB82532_DAFO_CHL8; bits = 10; break;
704               /* Never happens, but GCC is too dumb to figure it out */
705               default:  dafo = SAB82532_DAFO_CHL5; bits = 7; break;
706         }
707
708         if (cflag & CSTOPB) {
709                 dafo |= SAB82532_DAFO_STOP;
710                 bits++;
711         }
712
713         if (cflag & PARENB) {
714                 dafo |= SAB82532_DAFO_PARE;
715                 bits++;
716         }
717
718         if (cflag & PARODD) {
719                 dafo |= SAB82532_DAFO_PAR_ODD;
720         } else {
721                 dafo |= SAB82532_DAFO_PAR_EVEN;
722         }
723         up->cached_dafo = dafo;
724
725         calc_ebrg(baud, &n, &m);
726
727         up->cached_ebrg = n | (m << 6);
728
729         up->tec_timeout = (10 * 1000000) / baud;
730         up->cec_timeout = up->tec_timeout >> 2;
731
732         /* CTS flow control flags */
733         /* We encode read_status_mask and ignore_status_mask like so:
734          *
735          * ---------------------
736          * | ... | ISR1 | ISR0 |
737          * ---------------------
738          *  ..    15   8 7    0
739          */
740
741         up->port.read_status_mask = (SAB82532_ISR0_TCD | SAB82532_ISR0_TIME |
742                                      SAB82532_ISR0_RFO | SAB82532_ISR0_RPF |
743                                      SAB82532_ISR0_CDSC);
744         up->port.read_status_mask |= (SAB82532_ISR1_CSC |
745                                       SAB82532_ISR1_ALLS |
746                                       SAB82532_ISR1_XPR) << 8;
747         if (iflag & INPCK)
748                 up->port.read_status_mask |= (SAB82532_ISR0_PERR |
749                                               SAB82532_ISR0_FERR);
750         if (iflag & (BRKINT | PARMRK))
751                 up->port.read_status_mask |= (SAB82532_ISR1_BRK << 8);
752
753         /*
754          * Characteres to ignore
755          */
756         up->port.ignore_status_mask = 0;
757         if (iflag & IGNPAR)
758                 up->port.ignore_status_mask |= (SAB82532_ISR0_PERR |
759                                                 SAB82532_ISR0_FERR);
760         if (iflag & IGNBRK) {
761                 up->port.ignore_status_mask |= (SAB82532_ISR1_BRK << 8);
762                 /*
763                  * If we're ignoring parity and break indicators,
764                  * ignore overruns too (for real raw support).
765                  */
766                 if (iflag & IGNPAR)
767                         up->port.ignore_status_mask |= SAB82532_ISR0_RFO;
768         }
769
770         /*
771          * ignore all characters if CREAD is not set
772          */
773         if ((cflag & CREAD) == 0)
774                 up->port.ignore_status_mask |= (SAB82532_ISR0_RPF |
775                                                 SAB82532_ISR0_TCD);
776
777         uart_update_timeout(&up->port, cflag,
778                             (up->port.uartclk / (16 * quot)));
779
780         /* Now schedule a register update when the chip's
781          * transmitter is idle.
782          */
783         up->cached_mode |= SAB82532_MODE_RAC;
784         set_bit(SAB82532_REGS_PENDING, &up->irqflags);
785         if (test_bit(SAB82532_XPR, &up->irqflags))
786                 sunsab_tx_idle(up);
787 }
788
789 /* port->lock is not held.  */
790 static void sunsab_set_termios(struct uart_port *port, struct termios *termios,
791                                struct termios *old)
792 {
793         struct uart_sunsab_port *up = (struct uart_sunsab_port *) port;
794         unsigned long flags;
795         unsigned int baud = uart_get_baud_rate(port, termios, old, 0, 4000000);
796         unsigned int quot = uart_get_divisor(port, baud);
797
798         spin_lock_irqsave(&up->port.lock, flags);
799         sunsab_convert_to_sab(up, termios->c_cflag, termios->c_iflag, baud, quot);
800         spin_unlock_irqrestore(&up->port.lock, flags);
801 }
802
803 static const char *sunsab_type(struct uart_port *port)
804 {
805         struct uart_sunsab_port *up = (void *)port;
806         static char buf[36];
807         
808         sprintf(buf, "SAB82532 %s", sab82532_version[up->type]);
809         return buf;
810 }
811
812 static void sunsab_release_port(struct uart_port *port)
813 {
814 }
815
816 static int sunsab_request_port(struct uart_port *port)
817 {
818         return 0;
819 }
820
821 static void sunsab_config_port(struct uart_port *port, int flags)
822 {
823 }
824
825 static int sunsab_verify_port(struct uart_port *port, struct serial_struct *ser)
826 {
827         return -EINVAL;
828 }
829
830 static struct uart_ops sunsab_pops = {
831         .tx_empty       = sunsab_tx_empty,
832         .set_mctrl      = sunsab_set_mctrl,
833         .get_mctrl      = sunsab_get_mctrl,
834         .stop_tx        = sunsab_stop_tx,
835         .start_tx       = sunsab_start_tx,
836         .send_xchar     = sunsab_send_xchar,
837         .stop_rx        = sunsab_stop_rx,
838         .enable_ms      = sunsab_enable_ms,
839         .break_ctl      = sunsab_break_ctl,
840         .startup        = sunsab_startup,
841         .shutdown       = sunsab_shutdown,
842         .set_termios    = sunsab_set_termios,
843         .type           = sunsab_type,
844         .release_port   = sunsab_release_port,
845         .request_port   = sunsab_request_port,
846         .config_port    = sunsab_config_port,
847         .verify_port    = sunsab_verify_port,
848 };
849
850 static struct uart_driver sunsab_reg = {
851         .owner                  = THIS_MODULE,
852         .driver_name            = "serial",
853         .dev_name               = "ttyS",
854         .major                  = TTY_MAJOR,
855 };
856
857 static struct uart_sunsab_port *sunsab_ports;
858 static int num_channels;
859
860 #ifdef CONFIG_SERIAL_SUNSAB_CONSOLE
861
862 static void sunsab_console_putchar(struct uart_port *port, int c)
863 {
864         struct uart_sunsab_port *up = (struct uart_sunsab_port *)port;
865         unsigned long flags;
866
867         spin_lock_irqsave(&up->port.lock, flags);
868
869         sunsab_tec_wait(up);
870         writeb(c, &up->regs->w.tic);
871
872         spin_unlock_irqrestore(&up->port.lock, flags);
873 }
874
875 static void sunsab_console_write(struct console *con, const char *s, unsigned n)
876 {
877         struct uart_sunsab_port *up = &sunsab_ports[con->index];
878
879         uart_console_write(&up->port, s, n, sunsab_console_putchar);
880         sunsab_tec_wait(up);
881 }
882
883 static int sunsab_console_setup(struct console *con, char *options)
884 {
885         struct uart_sunsab_port *up = &sunsab_ports[con->index];
886         unsigned long flags;
887         unsigned int baud, quot;
888
889         printk("Console: ttyS%d (SAB82532)\n",
890                (sunsab_reg.minor - 64) + con->index);
891
892         sunserial_console_termios(con);
893
894         switch (con->cflag & CBAUD) {
895         case B150: baud = 150; break;
896         case B300: baud = 300; break;
897         case B600: baud = 600; break;
898         case B1200: baud = 1200; break;
899         case B2400: baud = 2400; break;
900         case B4800: baud = 4800; break;
901         default: case B9600: baud = 9600; break;
902         case B19200: baud = 19200; break;
903         case B38400: baud = 38400; break;
904         case B57600: baud = 57600; break;
905         case B115200: baud = 115200; break;
906         case B230400: baud = 230400; break;
907         case B460800: baud = 460800; break;
908         };
909
910         /*
911          * Temporary fix.
912          */
913         spin_lock_init(&up->port.lock);
914
915         /*
916          * Initialize the hardware
917          */
918         sunsab_startup(&up->port);
919
920         spin_lock_irqsave(&up->port.lock, flags);
921
922         /*
923          * Finally, enable interrupts
924          */
925         up->interrupt_mask0 = SAB82532_IMR0_PERR | SAB82532_IMR0_FERR |
926                                 SAB82532_IMR0_PLLA | SAB82532_IMR0_CDSC;
927         writeb(up->interrupt_mask0, &up->regs->w.imr0);
928         up->interrupt_mask1 = SAB82532_IMR1_BRKT | SAB82532_IMR1_ALLS |
929                                 SAB82532_IMR1_XOFF | SAB82532_IMR1_TIN |
930                                 SAB82532_IMR1_CSC | SAB82532_IMR1_XON |
931                                 SAB82532_IMR1_XPR;
932         writeb(up->interrupt_mask1, &up->regs->w.imr1);
933
934         quot = uart_get_divisor(&up->port, baud);
935         sunsab_convert_to_sab(up, con->cflag, 0, baud, quot);
936         sunsab_set_mctrl(&up->port, TIOCM_DTR | TIOCM_RTS);
937
938         spin_unlock_irqrestore(&up->port.lock, flags);
939         
940         return 0;
941 }
942
943 static struct console sunsab_console = {
944         .name   =       "ttyS",
945         .write  =       sunsab_console_write,
946         .device =       uart_console_device,
947         .setup  =       sunsab_console_setup,
948         .flags  =       CON_PRINTBUFFER,
949         .index  =       -1,
950         .data   =       &sunsab_reg,
951 };
952
953 static inline struct console *SUNSAB_CONSOLE(void)
954 {
955         int i;
956
957         if (con_is_present())
958                 return NULL;
959
960         for (i = 0; i < num_channels; i++) {
961                 int this_minor = sunsab_reg.minor + i;
962
963                 if ((this_minor - 64) == (serial_console - 1))
964                         break;
965         }
966         if (i == num_channels)
967                 return NULL;
968
969         sunsab_console.index = i;
970
971         return &sunsab_console;
972 }
973 #else
974 #define SUNSAB_CONSOLE()        (NULL)
975 #define sunsab_console_init()   do { } while (0)
976 #endif
977
978 static int __devinit sunsab_init_one(struct uart_sunsab_port *up,
979                                      struct of_device *op,
980                                      unsigned long offset,
981                                      int line)
982 {
983         up->port.line = line;
984         up->port.dev = &op->dev;
985
986         up->port.mapbase = op->resource[0].start + offset;
987         up->port.membase = of_ioremap(&op->resource[0], offset,
988                                       sizeof(union sab82532_async_regs),
989                                       "sab");
990         if (!up->port.membase)
991                 return -ENOMEM;
992         up->regs = (union sab82532_async_regs __iomem *) up->port.membase;
993
994         up->port.irq = op->irqs[0];
995
996         up->port.fifosize = SAB82532_XMIT_FIFO_SIZE;
997         up->port.iotype = UPIO_MEM;
998
999         writeb(SAB82532_IPC_IC_ACT_LOW, &up->regs->w.ipc);
1000
1001         up->port.ops = &sunsab_pops;
1002         up->port.type = PORT_SUNSAB;
1003         up->port.uartclk = SAB_BASE_BAUD;
1004
1005         up->type = readb(&up->regs->r.vstr) & 0x0f;
1006         writeb(~((1 << 1) | (1 << 2) | (1 << 4)), &up->regs->w.pcr);
1007         writeb(0xff, &up->regs->w.pim);
1008         if ((up->port.line & 0x1) == 0) {
1009                 up->pvr_dsr_bit = (1 << 0);
1010                 up->pvr_dtr_bit = (1 << 1);
1011         } else {
1012                 up->pvr_dsr_bit = (1 << 3);
1013                 up->pvr_dtr_bit = (1 << 2);
1014         }
1015         up->cached_pvr = (1 << 1) | (1 << 2) | (1 << 4);
1016         writeb(up->cached_pvr, &up->regs->w.pvr);
1017         up->cached_mode = readb(&up->regs->rw.mode);
1018         up->cached_mode |= SAB82532_MODE_FRTS;
1019         writeb(up->cached_mode, &up->regs->rw.mode);
1020         up->cached_mode |= SAB82532_MODE_RTS;
1021         writeb(up->cached_mode, &up->regs->rw.mode);
1022
1023         up->tec_timeout = SAB82532_MAX_TEC_TIMEOUT;
1024         up->cec_timeout = SAB82532_MAX_CEC_TIMEOUT;
1025
1026         if (!(up->port.line & 0x01)) {
1027                 int err;
1028
1029                 err = request_irq(up->port.irq, sunsab_interrupt,
1030                                   IRQF_SHARED, "sab", up);
1031                 if (err) {
1032                         of_iounmap(up->port.membase,
1033                                    sizeof(union sab82532_async_regs));
1034                         return err;
1035                 }
1036         }
1037
1038         return 0;
1039 }
1040
1041 static int __devinit sab_probe(struct of_device *op, const struct of_device_id *match)
1042 {
1043         static int inst;
1044         struct uart_sunsab_port *up;
1045         int err;
1046
1047         up = &sunsab_ports[inst * 2];
1048
1049         err = sunsab_init_one(&up[0], op,
1050                               sizeof(union sab82532_async_regs),
1051                               (inst * 2) + 0);
1052         if (err)
1053                 return err;
1054
1055         err = sunsab_init_one(&up[0], op, 0,
1056                               (inst * 2) + 1);
1057         if (err) {
1058                 of_iounmap(up[0].port.membase,
1059                            sizeof(union sab82532_async_regs));
1060                 free_irq(up[0].port.irq, &up[0]);
1061                 return err;
1062         }
1063
1064         uart_add_one_port(&sunsab_reg, &up[0].port);
1065         uart_add_one_port(&sunsab_reg, &up[1].port);
1066
1067         dev_set_drvdata(&op->dev, &up[0]);
1068
1069         inst++;
1070
1071         return 0;
1072 }
1073
1074 static void __devexit sab_remove_one(struct uart_sunsab_port *up)
1075 {
1076         uart_remove_one_port(&sunsab_reg, &up->port);
1077         if (!(up->port.line & 1))
1078                 free_irq(up->port.irq, up);
1079         of_iounmap(up->port.membase,
1080                    sizeof(union sab82532_async_regs));
1081 }
1082
1083 static int __devexit sab_remove(struct of_device *op)
1084 {
1085         struct uart_sunsab_port *up = dev_get_drvdata(&op->dev);
1086
1087         sab_remove_one(&up[0]);
1088         sab_remove_one(&up[1]);
1089
1090         dev_set_drvdata(&op->dev, NULL);
1091
1092         return 0;
1093 }
1094
1095 static struct of_device_id sab_match[] = {
1096         {
1097                 .name = "se",
1098         },
1099         {
1100                 .name = "serial",
1101                 .compatible = "sab82532",
1102         },
1103         {},
1104 };
1105 MODULE_DEVICE_TABLE(of, sab_match);
1106
1107 static struct of_platform_driver sab_driver = {
1108         .name           = "sab",
1109         .match_table    = sab_match,
1110         .probe          = sab_probe,
1111         .remove         = __devexit_p(sab_remove),
1112 };
1113
1114 static int __init sunsab_init(void)
1115 {
1116         struct device_node *dp;
1117         int err;
1118
1119         num_channels = 0;
1120         for_each_node_by_name(dp, "su")
1121                 num_channels += 2;
1122         for_each_node_by_name(dp, "serial") {
1123                 if (of_device_is_compatible(dp, "sab82532"))
1124                         num_channels += 2;
1125         }
1126
1127         if (num_channels) {
1128                 sunsab_ports = kzalloc(sizeof(struct uart_sunsab_port) *
1129                                        num_channels, GFP_KERNEL);
1130                 if (!sunsab_ports)
1131                         return -ENOMEM;
1132
1133                 sunsab_reg.minor = sunserial_current_minor;
1134                 sunsab_reg.nr = num_channels;
1135
1136                 err = uart_register_driver(&sunsab_reg);
1137                 if (err) {
1138                         kfree(sunsab_ports);
1139                         sunsab_ports = NULL;
1140
1141                         return err;
1142                 }
1143
1144                 sunsab_reg.tty_driver->name_base = sunsab_reg.minor - 64;
1145                 sunsab_reg.cons = SUNSAB_CONSOLE();
1146                 sunserial_current_minor += num_channels;
1147         }
1148
1149         return of_register_driver(&sab_driver, &of_bus_type);
1150 }
1151
1152 static void __exit sunsab_exit(void)
1153 {
1154         of_unregister_driver(&sab_driver);
1155         if (num_channels) {
1156                 sunserial_current_minor -= num_channels;
1157                 uart_unregister_driver(&sunsab_reg);
1158         }
1159
1160         kfree(sunsab_ports);
1161         sunsab_ports = NULL;
1162 }
1163
1164 module_init(sunsab_init);
1165 module_exit(sunsab_exit);
1166
1167 MODULE_AUTHOR("Eddie C. Dost and David S. Miller");
1168 MODULE_DESCRIPTION("Sun SAB82532 serial port driver");
1169 MODULE_LICENSE("GPL");