Input: cleanup ps2_command() timeout handling in libps2.
[linux-2.6] / drivers / input / serio / hp_sdc.c
1 /*
2  * HP i8042-based System Device Controller driver.
3  *
4  * Copyright (c) 2001 Brian S. Julin
5  * All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions, and the following disclaimer,
12  *    without modification.
13  * 2. The name of the author may not be used to endorse or promote products
14  *    derived from this software without specific prior written permission.
15  *
16  * Alternatively, this software may be distributed under the terms of the
17  * GNU General Public License ("GPL").
18  *
19  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
20  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22  * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE FOR
23  * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28  *
29  * References:
30  * System Device Controller Microprocessor Firmware Theory of Operation
31  *      for Part Number 1820-4784 Revision B.  Dwg No. A-1820-4784-2
32  * Helge Deller's original hilkbd.c port for PA-RISC.
33  *
34  *
35  * Driver theory of operation:
36  *
37  * hp_sdc_put does all writing to the SDC.  ISR can run on a different 
38  * CPU than hp_sdc_put, but only one CPU runs hp_sdc_put at a time 
39  * (it cannot really benefit from SMP anyway.)  A tasket fit this perfectly.
40  *
41  * All data coming back from the SDC is sent via interrupt and can be read 
42  * fully in the ISR, so there are no latency/throughput problems there.  
43  * The problem is with output, due to the slow clock speed of the SDC 
44  * compared to the CPU.  This should not be too horrible most of the time, 
45  * but if used with HIL devices that support the multibyte transfer command, 
46  * keeping outbound throughput flowing at the 6500KBps that the HIL is 
47  * capable of is more than can be done at HZ=100.
48  *
49  * Busy polling for IBF clear wastes CPU cycles and bus cycles.  hp_sdc.ibf 
50  * is set to 0 when the IBF flag in the status register has cleared.  ISR 
51  * may do this, and may also access the parts of queued transactions related 
52  * to reading data back from the SDC, but otherwise will not touch the 
53  * hp_sdc state. Whenever a register is written hp_sdc.ibf is set to 1.
54  *
55  * The i8042 write index and the values in the 4-byte input buffer
56  * starting at 0x70 are kept track of in hp_sdc.wi, and .r7[], respectively,
57  * to minimize the amount of IO needed to the SDC.  However these values 
58  * do not need to be locked since they are only ever accessed by hp_sdc_put.
59  *
60  * A timer task schedules the tasklet once per second just to make
61  * sure it doesn't freeze up and to allow for bad reads to time out.
62  */
63
64 #include <linux/hp_sdc.h>
65 #include <linux/sched.h>
66 #include <linux/errno.h>
67 #include <linux/init.h>
68 #include <linux/module.h>
69 #include <linux/ioport.h>
70 #include <linux/time.h>
71 #include <linux/slab.h>
72 #include <linux/hil.h>
73 #include <asm/io.h>
74 #include <asm/system.h>
75
76 /* Machine-specific abstraction */
77
78 #if defined(__hppa__)
79 # include <asm/parisc-device.h>
80 # define sdc_readb(p)           gsc_readb(p)
81 # define sdc_writeb(v,p)        gsc_writeb((v),(p))
82 #elif defined(__mc68000__)
83 # include <asm/uaccess.h>
84 # define sdc_readb(p)           in_8(p)
85 # define sdc_writeb(v,p)        out_8((p),(v))
86 #else
87 # error "HIL is not supported on this platform"
88 #endif
89
90 #define PREFIX "HP SDC: "
91
92 MODULE_AUTHOR("Brian S. Julin <bri@calyx.com>");
93 MODULE_DESCRIPTION("HP i8042-based SDC Driver");
94 MODULE_LICENSE("Dual BSD/GPL");
95
96 EXPORT_SYMBOL(hp_sdc_request_timer_irq);
97 EXPORT_SYMBOL(hp_sdc_request_hil_irq);
98 EXPORT_SYMBOL(hp_sdc_request_cooked_irq);
99
100 EXPORT_SYMBOL(hp_sdc_release_timer_irq);
101 EXPORT_SYMBOL(hp_sdc_release_hil_irq);
102 EXPORT_SYMBOL(hp_sdc_release_cooked_irq);
103
104 EXPORT_SYMBOL(hp_sdc_enqueue_transaction);
105 EXPORT_SYMBOL(hp_sdc_dequeue_transaction);
106
107 static hp_i8042_sdc     hp_sdc; /* All driver state is kept in here. */
108
109 /*************** primitives for use in any context *********************/
110 static inline uint8_t hp_sdc_status_in8 (void) {
111         uint8_t status;
112         unsigned long flags;
113
114         write_lock_irqsave(&hp_sdc.ibf_lock, flags);
115         status = sdc_readb(hp_sdc.status_io);
116         if (!(status & HP_SDC_STATUS_IBF)) hp_sdc.ibf = 0;
117         write_unlock_irqrestore(&hp_sdc.ibf_lock, flags);
118
119         return status;
120 }
121
122 static inline uint8_t hp_sdc_data_in8 (void) {
123         return sdc_readb(hp_sdc.data_io); 
124 }
125
126 static inline void hp_sdc_status_out8 (uint8_t val) {
127         unsigned long flags;
128
129         write_lock_irqsave(&hp_sdc.ibf_lock, flags);
130         hp_sdc.ibf = 1;
131         if ((val & 0xf0) == 0xe0) hp_sdc.wi = 0xff;
132         sdc_writeb(val, hp_sdc.status_io);
133         write_unlock_irqrestore(&hp_sdc.ibf_lock, flags);
134 }
135
136 static inline void hp_sdc_data_out8 (uint8_t val) {
137         unsigned long flags;
138
139         write_lock_irqsave(&hp_sdc.ibf_lock, flags);
140         hp_sdc.ibf = 1;
141         sdc_writeb(val, hp_sdc.data_io);
142         write_unlock_irqrestore(&hp_sdc.ibf_lock, flags);
143 }
144
145 /*      Care must be taken to only invoke hp_sdc_spin_ibf when 
146  *      absolutely needed, or in rarely invoked subroutines.  
147  *      Not only does it waste CPU cycles, it also wastes bus cycles. 
148  */
149 static inline void hp_sdc_spin_ibf(void) {
150         unsigned long flags;
151         rwlock_t *lock;
152
153         lock = &hp_sdc.ibf_lock;
154
155         read_lock_irqsave(lock, flags);
156         if (!hp_sdc.ibf) {
157                 read_unlock_irqrestore(lock, flags);
158                 return;
159         }
160         read_unlock(lock);
161         write_lock(lock);
162         while (sdc_readb(hp_sdc.status_io) & HP_SDC_STATUS_IBF) {};
163         hp_sdc.ibf = 0;
164         write_unlock_irqrestore(lock, flags);
165 }
166
167
168 /************************ Interrupt context functions ************************/
169 static void hp_sdc_take (int irq, void *dev_id, uint8_t status, uint8_t data) {
170         hp_sdc_transaction *curr;
171
172         read_lock(&hp_sdc.rtq_lock);
173         if (hp_sdc.rcurr < 0) {
174                 read_unlock(&hp_sdc.rtq_lock);
175                 return;
176         }
177         curr = hp_sdc.tq[hp_sdc.rcurr];
178         read_unlock(&hp_sdc.rtq_lock);
179
180         curr->seq[curr->idx++] = status;
181         curr->seq[curr->idx++] = data;
182         hp_sdc.rqty -= 2;
183         do_gettimeofday(&hp_sdc.rtv);
184
185         if (hp_sdc.rqty <= 0) {
186                 /* All data has been gathered. */
187                 if(curr->seq[curr->actidx] & HP_SDC_ACT_SEMAPHORE) {
188                         if (curr->act.semaphore) up(curr->act.semaphore);
189                 }
190                 if(curr->seq[curr->actidx] & HP_SDC_ACT_CALLBACK) {
191                         if (curr->act.irqhook)
192                                 curr->act.irqhook(irq, dev_id, status, data);
193                 }
194                 curr->actidx = curr->idx;
195                 curr->idx++;
196                 /* Return control of this transaction */
197                 write_lock(&hp_sdc.rtq_lock);
198                 hp_sdc.rcurr = -1; 
199                 hp_sdc.rqty = 0;
200                 write_unlock(&hp_sdc.rtq_lock);
201                 tasklet_schedule(&hp_sdc.task);
202         }
203 }
204
205 static irqreturn_t hp_sdc_isr(int irq, void *dev_id, struct pt_regs * regs) {
206         uint8_t status, data;
207
208         status = hp_sdc_status_in8();
209         /* Read data unconditionally to advance i8042. */
210         data =   hp_sdc_data_in8();
211
212         /* For now we are ignoring these until we get the SDC to behave. */
213         if (((status & 0xf1) == 0x51) && data == 0x82) {
214           return IRQ_HANDLED;
215         }
216
217         switch(status & HP_SDC_STATUS_IRQMASK) {
218               case 0: /* This case is not documented. */
219                 break;
220               case HP_SDC_STATUS_USERTIMER:
221               case HP_SDC_STATUS_PERIODIC:
222               case HP_SDC_STATUS_TIMER:
223                 read_lock(&hp_sdc.hook_lock);
224                 if (hp_sdc.timer != NULL)
225                         hp_sdc.timer(irq, dev_id, status, data);
226                 read_unlock(&hp_sdc.hook_lock);
227                 break;
228               case HP_SDC_STATUS_REG:
229                 hp_sdc_take(irq, dev_id, status, data);
230                 break;
231               case HP_SDC_STATUS_HILCMD:
232               case HP_SDC_STATUS_HILDATA:
233                 read_lock(&hp_sdc.hook_lock);
234                 if (hp_sdc.hil != NULL)
235                         hp_sdc.hil(irq, dev_id, status, data);
236                 read_unlock(&hp_sdc.hook_lock);
237                 break;
238               case HP_SDC_STATUS_PUP:
239                 read_lock(&hp_sdc.hook_lock);
240                 if (hp_sdc.pup != NULL)
241                         hp_sdc.pup(irq, dev_id, status, data);
242                 else printk(KERN_INFO PREFIX "HP SDC reports successful PUP.\n");
243                 read_unlock(&hp_sdc.hook_lock);
244                 break;
245               default:
246                 read_lock(&hp_sdc.hook_lock);
247                 if (hp_sdc.cooked != NULL)
248                         hp_sdc.cooked(irq, dev_id, status, data);
249                 read_unlock(&hp_sdc.hook_lock);
250                 break;
251         }
252         return IRQ_HANDLED;
253 }
254
255
256 static irqreturn_t hp_sdc_nmisr(int irq, void *dev_id, struct pt_regs * regs) {
257         int status;
258         
259         status = hp_sdc_status_in8();
260         printk(KERN_WARNING PREFIX "NMI !\n");
261
262 #if 0   
263         if (status & HP_SDC_NMISTATUS_FHS) {
264                 read_lock(&hp_sdc.hook_lock);
265                 if (hp_sdc.timer != NULL)
266                         hp_sdc.timer(irq, dev_id, status, 0);
267                 read_unlock(&hp_sdc.hook_lock);
268         }
269         else {
270                 /* TODO: pass this on to the HIL handler, or do SAK here? */
271                 printk(KERN_WARNING PREFIX "HIL NMI\n");
272         }
273 #endif
274         return IRQ_HANDLED;
275 }
276
277
278 /***************** Kernel (tasklet) context functions ****************/
279
280 unsigned long hp_sdc_put(void);
281
282 static void hp_sdc_tasklet(unsigned long foo) {
283
284         write_lock_irq(&hp_sdc.rtq_lock);
285         if (hp_sdc.rcurr >= 0) {
286                 struct timeval tv;
287                 do_gettimeofday(&tv);
288                 if (tv.tv_sec > hp_sdc.rtv.tv_sec) tv.tv_usec += 1000000;
289                 if (tv.tv_usec - hp_sdc.rtv.tv_usec > HP_SDC_MAX_REG_DELAY) {
290                         hp_sdc_transaction *curr;
291                         uint8_t tmp;
292
293                         curr = hp_sdc.tq[hp_sdc.rcurr];
294                         /* If this turns out to be a normal failure mode
295                          * we'll need to figure out a way to communicate
296                          * it back to the application. and be less verbose.
297                          */
298                         printk(KERN_WARNING PREFIX "read timeout (%ius)!\n",
299                                tv.tv_usec - hp_sdc.rtv.tv_usec);
300                         curr->idx += hp_sdc.rqty;
301                         hp_sdc.rqty = 0;
302                         tmp = curr->seq[curr->actidx];
303                         curr->seq[curr->actidx] |= HP_SDC_ACT_DEAD;
304                         if(tmp & HP_SDC_ACT_SEMAPHORE) {
305                                 if (curr->act.semaphore) 
306                                         up(curr->act.semaphore);
307                         }
308                         if(tmp & HP_SDC_ACT_CALLBACK) {
309                                 /* Note this means that irqhooks may be called
310                                  * in tasklet/bh context.
311                                  */
312                                 if (curr->act.irqhook) 
313                                         curr->act.irqhook(0, 0, 0, 0);
314                         }
315                         curr->actidx = curr->idx;
316                         curr->idx++;
317                         hp_sdc.rcurr = -1; 
318                 }
319         }
320         write_unlock_irq(&hp_sdc.rtq_lock);
321         hp_sdc_put();
322 }
323
324 unsigned long hp_sdc_put(void) {
325         hp_sdc_transaction *curr;
326         uint8_t act;
327         int idx, curridx;
328
329         int limit = 0;
330
331         write_lock(&hp_sdc.lock);
332
333         /* If i8042 buffers are full, we cannot do anything that
334            requires output, so we skip to the administrativa. */
335         if (hp_sdc.ibf) {
336                 hp_sdc_status_in8();
337                 if (hp_sdc.ibf) goto finish;
338         }
339
340  anew:
341         /* See if we are in the middle of a sequence. */
342         if (hp_sdc.wcurr < 0) hp_sdc.wcurr = 0;
343         read_lock_irq(&hp_sdc.rtq_lock);
344         if (hp_sdc.rcurr == hp_sdc.wcurr) hp_sdc.wcurr++;
345         read_unlock_irq(&hp_sdc.rtq_lock);
346         if (hp_sdc.wcurr >= HP_SDC_QUEUE_LEN) hp_sdc.wcurr = 0;
347         curridx = hp_sdc.wcurr;
348
349         if (hp_sdc.tq[curridx] != NULL) goto start;
350
351         while (++curridx != hp_sdc.wcurr) {
352                 if (curridx >= HP_SDC_QUEUE_LEN) {
353                         curridx = -1; /* Wrap to top */
354                         continue;
355                 }
356                 read_lock_irq(&hp_sdc.rtq_lock);
357                 if (hp_sdc.rcurr == curridx) {
358                         read_unlock_irq(&hp_sdc.rtq_lock);
359                         continue;
360                 }
361                 read_unlock_irq(&hp_sdc.rtq_lock);
362                 if (hp_sdc.tq[curridx] != NULL) break; /* Found one. */
363         }
364         if (curridx == hp_sdc.wcurr) { /* There's nothing queued to do. */
365                 curridx = -1;
366         }
367         hp_sdc.wcurr = curridx;
368
369  start:
370
371         /* Check to see if the interrupt mask needs to be set. */
372         if (hp_sdc.set_im) {
373                 hp_sdc_status_out8(hp_sdc.im | HP_SDC_CMD_SET_IM);
374                 hp_sdc.set_im = 0;
375                 goto finish;
376         }
377
378         if (hp_sdc.wcurr == -1) goto done;
379
380         curr = hp_sdc.tq[curridx];
381         idx = curr->actidx;
382
383         if (curr->actidx >= curr->endidx) {
384                 hp_sdc.tq[curridx] = NULL;
385                 /* Interleave outbound data between the transactions. */
386                 hp_sdc.wcurr++;
387                 if (hp_sdc.wcurr >= HP_SDC_QUEUE_LEN) hp_sdc.wcurr = 0;
388                 goto finish;    
389         }
390
391         act = curr->seq[idx];
392         idx++;
393
394         if (curr->idx >= curr->endidx) {
395                 if (act & HP_SDC_ACT_DEALLOC) kfree(curr);
396                 hp_sdc.tq[curridx] = NULL;
397                 /* Interleave outbound data between the transactions. */
398                 hp_sdc.wcurr++;
399                 if (hp_sdc.wcurr >= HP_SDC_QUEUE_LEN) hp_sdc.wcurr = 0;
400                 goto finish;    
401         }
402
403         while (act & HP_SDC_ACT_PRECMD) {
404                 if (curr->idx != idx) {
405                         idx++;
406                         act &= ~HP_SDC_ACT_PRECMD;
407                         break;
408                 }
409                 hp_sdc_status_out8(curr->seq[idx]);
410                 curr->idx++;
411                 /* act finished? */
412                 if ((act & HP_SDC_ACT_DURING) == HP_SDC_ACT_PRECMD)
413                   goto actdone;
414                 /* skip quantity field if data-out sequence follows. */
415                 if (act & HP_SDC_ACT_DATAOUT) curr->idx++;
416                 goto finish;
417         }
418         if (act & HP_SDC_ACT_DATAOUT) {
419                 int qty;
420
421                 qty = curr->seq[idx];
422                 idx++;
423                 if (curr->idx - idx < qty) {
424                         hp_sdc_data_out8(curr->seq[curr->idx]);
425                         curr->idx++;
426                         /* act finished? */
427                         if ((curr->idx - idx >= qty) && 
428                             ((act & HP_SDC_ACT_DURING) == HP_SDC_ACT_DATAOUT))
429                                 goto actdone;
430                         goto finish;
431                 }
432                 idx += qty;
433                 act &= ~HP_SDC_ACT_DATAOUT;
434         }
435         else while (act & HP_SDC_ACT_DATAREG) {
436                 int mask;
437                 uint8_t w7[4];
438
439                 mask = curr->seq[idx];
440                 if (idx != curr->idx) {
441                         idx++;
442                         idx += !!(mask & 1);
443                         idx += !!(mask & 2);
444                         idx += !!(mask & 4);
445                         idx += !!(mask & 8);
446                         act &= ~HP_SDC_ACT_DATAREG;
447                         break;
448                 }
449                 
450                 w7[0] = (mask & 1) ? curr->seq[++idx] : hp_sdc.r7[0];
451                 w7[1] = (mask & 2) ? curr->seq[++idx] : hp_sdc.r7[1];
452                 w7[2] = (mask & 4) ? curr->seq[++idx] : hp_sdc.r7[2];
453                 w7[3] = (mask & 8) ? curr->seq[++idx] : hp_sdc.r7[3];
454                 
455                 if (hp_sdc.wi > 0x73 || hp_sdc.wi < 0x70 ||
456                         w7[hp_sdc.wi-0x70] == hp_sdc.r7[hp_sdc.wi-0x70]) {
457                         int i = 0;
458
459                         /* Need to point the write index register */    
460                         while ((i < 4) && w7[i] == hp_sdc.r7[i]) i++;
461                         if (i < 4) {
462                                 hp_sdc_status_out8(HP_SDC_CMD_SET_D0 + i);
463                                 hp_sdc.wi = 0x70 + i;
464                                 goto finish;
465                         }
466                         idx++;
467                         if ((act & HP_SDC_ACT_DURING) == HP_SDC_ACT_DATAREG)
468                                 goto actdone;
469                         curr->idx = idx;
470                         act &= ~HP_SDC_ACT_DATAREG;
471                         break;
472                 }
473
474                 hp_sdc_data_out8(w7[hp_sdc.wi - 0x70]);
475                 hp_sdc.r7[hp_sdc.wi - 0x70] = w7[hp_sdc.wi - 0x70];
476                 hp_sdc.wi++; /* write index register autoincrements */
477                 {
478                         int i = 0;
479
480                         while ((i < 4) && w7[i] == hp_sdc.r7[i]) i++;
481                         if (i >= 4) {
482                                 curr->idx = idx + 1;
483                                 if ((act & HP_SDC_ACT_DURING) == 
484                                     HP_SDC_ACT_DATAREG)
485                                         goto actdone;
486                         }
487                 }
488                 goto finish;
489         }
490         /* We don't go any further in the command if there is a pending read,
491            because we don't want interleaved results. */
492         read_lock_irq(&hp_sdc.rtq_lock);
493         if (hp_sdc.rcurr >= 0) {
494                 read_unlock_irq(&hp_sdc.rtq_lock);
495                 goto finish;
496         }
497         read_unlock_irq(&hp_sdc.rtq_lock);
498
499
500         if (act & HP_SDC_ACT_POSTCMD) {
501                 uint8_t postcmd;
502
503                 /* curr->idx should == idx at this point. */
504                 postcmd = curr->seq[idx];
505                 curr->idx++;
506                 if (act & HP_SDC_ACT_DATAIN) {
507
508                         /* Start a new read */
509                         hp_sdc.rqty = curr->seq[curr->idx];
510                         do_gettimeofday(&hp_sdc.rtv);
511                         curr->idx++;
512                         /* Still need to lock here in case of spurious irq. */
513                         write_lock_irq(&hp_sdc.rtq_lock);
514                         hp_sdc.rcurr = curridx; 
515                         write_unlock_irq(&hp_sdc.rtq_lock);
516                         hp_sdc_status_out8(postcmd);
517                         goto finish;
518                 }
519                 hp_sdc_status_out8(postcmd);
520                 goto actdone;
521         }
522
523 actdone:
524         if (act & HP_SDC_ACT_SEMAPHORE) {
525                 up(curr->act.semaphore);
526         }
527         else if (act & HP_SDC_ACT_CALLBACK) {
528                 curr->act.irqhook(0,0,0,0);
529         }
530         if (curr->idx >= curr->endidx) { /* This transaction is over. */
531                 if (act & HP_SDC_ACT_DEALLOC) kfree(curr);
532                 hp_sdc.tq[curridx] = NULL;
533         }
534         else {
535                 curr->actidx = idx + 1;
536                 curr->idx = idx + 2;
537         }
538         /* Interleave outbound data between the transactions. */
539         hp_sdc.wcurr++;
540         if (hp_sdc.wcurr >= HP_SDC_QUEUE_LEN) hp_sdc.wcurr = 0;
541
542  finish:
543         /* If by some quirk IBF has cleared and our ISR has run to 
544            see that that has happened, do it all again. */
545         if (!hp_sdc.ibf && limit++ < 20) goto anew;
546
547  done:
548         if (hp_sdc.wcurr >= 0) tasklet_schedule(&hp_sdc.task);
549         write_unlock(&hp_sdc.lock);
550         return 0;
551 }
552
553 /******* Functions called in either user or kernel context ****/
554 int hp_sdc_enqueue_transaction(hp_sdc_transaction *this) {
555         unsigned long flags;
556         int i;
557
558         if (this == NULL) {
559                 tasklet_schedule(&hp_sdc.task);
560                 return -EINVAL;
561         };
562
563         write_lock_irqsave(&hp_sdc.lock, flags);
564
565         /* Can't have same transaction on queue twice */
566         for (i=0; i < HP_SDC_QUEUE_LEN; i++)
567                 if (hp_sdc.tq[i] == this) goto fail;
568
569         this->actidx = 0;
570         this->idx = 1;
571
572         /* Search for empty slot */
573         for (i=0; i < HP_SDC_QUEUE_LEN; i++) {
574                 if (hp_sdc.tq[i] == NULL) {
575                         hp_sdc.tq[i] = this;
576                         write_unlock_irqrestore(&hp_sdc.lock, flags);
577                         tasklet_schedule(&hp_sdc.task);
578                         return 0;
579                 }
580         }
581         write_unlock_irqrestore(&hp_sdc.lock, flags);
582         printk(KERN_WARNING PREFIX "No free slot to add transaction.\n");
583         return -EBUSY;
584
585  fail:
586         write_unlock_irqrestore(&hp_sdc.lock,flags);
587         printk(KERN_WARNING PREFIX "Transaction add failed: transaction already queued?\n");
588         return -EINVAL;
589 }
590
591 int hp_sdc_dequeue_transaction(hp_sdc_transaction *this) {
592         unsigned long flags;
593         int i;
594
595         write_lock_irqsave(&hp_sdc.lock, flags);
596
597         /* TODO: don't remove it if it's not done. */
598
599         for (i=0; i < HP_SDC_QUEUE_LEN; i++)
600                 if (hp_sdc.tq[i] == this) hp_sdc.tq[i] = NULL;
601
602         write_unlock_irqrestore(&hp_sdc.lock, flags);
603         return 0;
604 }
605
606
607
608 /********************** User context functions **************************/
609 int hp_sdc_request_timer_irq(hp_sdc_irqhook *callback) {
610
611         if (callback == NULL || hp_sdc.dev == NULL) {
612                 return -EINVAL;
613         }
614         write_lock_irq(&hp_sdc.hook_lock);
615         if (hp_sdc.timer != NULL) {
616                 write_unlock_irq(&hp_sdc.hook_lock);
617                 return -EBUSY;
618         }
619
620         hp_sdc.timer = callback;
621         /* Enable interrupts from the timers */
622         hp_sdc.im &= ~HP_SDC_IM_FH;
623         hp_sdc.im &= ~HP_SDC_IM_PT;
624         hp_sdc.im &= ~HP_SDC_IM_TIMERS;
625         hp_sdc.set_im = 1;
626         write_unlock_irq(&hp_sdc.hook_lock);
627
628         tasklet_schedule(&hp_sdc.task);
629
630         return 0;
631 }
632
633 int hp_sdc_request_hil_irq(hp_sdc_irqhook *callback) {
634
635         if (callback == NULL || hp_sdc.dev == NULL) {
636                 return -EINVAL;
637         }
638         write_lock_irq(&hp_sdc.hook_lock);
639         if (hp_sdc.hil != NULL) {
640                 write_unlock_irq(&hp_sdc.hook_lock);
641                 return -EBUSY;
642         }
643
644         hp_sdc.hil = callback;
645         hp_sdc.im &= ~(HP_SDC_IM_HIL | HP_SDC_IM_RESET);
646         hp_sdc.set_im = 1;
647         write_unlock_irq(&hp_sdc.hook_lock);
648
649         tasklet_schedule(&hp_sdc.task);
650
651         return 0;
652 }
653
654 int hp_sdc_request_cooked_irq(hp_sdc_irqhook *callback) {
655
656         if (callback == NULL || hp_sdc.dev == NULL) {
657                 return -EINVAL;
658         }
659         write_lock_irq(&hp_sdc.hook_lock);
660         if (hp_sdc.cooked != NULL) {
661                 write_unlock_irq(&hp_sdc.hook_lock);
662                 return -EBUSY;
663         }
664
665         /* Enable interrupts from the HIL MLC */
666         hp_sdc.cooked = callback;
667         hp_sdc.im &= ~(HP_SDC_IM_HIL | HP_SDC_IM_RESET);
668         hp_sdc.set_im = 1;
669         write_unlock_irq(&hp_sdc.hook_lock);
670
671         tasklet_schedule(&hp_sdc.task);
672
673         return 0;
674 }
675
676 int hp_sdc_release_timer_irq(hp_sdc_irqhook *callback) {
677
678
679         write_lock_irq(&hp_sdc.hook_lock);
680         if ((callback != hp_sdc.timer) ||
681             (hp_sdc.timer == NULL)) {
682                 write_unlock_irq(&hp_sdc.hook_lock);
683                 return -EINVAL;
684         }
685
686         /* Disable interrupts from the timers */
687         hp_sdc.timer = NULL;
688         hp_sdc.im |= HP_SDC_IM_TIMERS;
689         hp_sdc.im |= HP_SDC_IM_FH;
690         hp_sdc.im |= HP_SDC_IM_PT;
691         hp_sdc.set_im = 1;
692         write_unlock_irq(&hp_sdc.hook_lock);
693         tasklet_schedule(&hp_sdc.task);
694
695         return 0;
696 }
697
698 int hp_sdc_release_hil_irq(hp_sdc_irqhook *callback) {
699
700         write_lock_irq(&hp_sdc.hook_lock);
701         if ((callback != hp_sdc.hil) ||
702             (hp_sdc.hil == NULL)) {
703                 write_unlock_irq(&hp_sdc.hook_lock);
704                 return -EINVAL;
705         }
706
707         hp_sdc.hil = NULL;
708         /* Disable interrupts from HIL only if there is no cooked driver. */
709         if(hp_sdc.cooked == NULL) {
710                 hp_sdc.im |= (HP_SDC_IM_HIL | HP_SDC_IM_RESET);
711                 hp_sdc.set_im = 1;
712         }
713         write_unlock_irq(&hp_sdc.hook_lock);
714         tasklet_schedule(&hp_sdc.task);
715
716         return 0;
717 }
718
719 int hp_sdc_release_cooked_irq(hp_sdc_irqhook *callback) {
720
721         write_lock_irq(&hp_sdc.hook_lock);
722         if ((callback != hp_sdc.cooked) ||
723             (hp_sdc.cooked == NULL)) {
724                 write_unlock_irq(&hp_sdc.hook_lock);
725                 return -EINVAL;
726         }
727
728         hp_sdc.cooked = NULL;
729         /* Disable interrupts from HIL only if there is no raw HIL driver. */
730         if(hp_sdc.hil == NULL) {
731                 hp_sdc.im |= (HP_SDC_IM_HIL | HP_SDC_IM_RESET);
732                 hp_sdc.set_im = 1;
733         }
734         write_unlock_irq(&hp_sdc.hook_lock);
735         tasklet_schedule(&hp_sdc.task);
736
737         return 0;
738 }
739
740 /************************* Keepalive timer task *********************/
741
742 void hp_sdc_kicker (unsigned long data) {
743         tasklet_schedule(&hp_sdc.task);
744         /* Re-insert the periodic task. */
745         mod_timer(&hp_sdc.kicker, jiffies + HZ);
746 }
747
748 /************************** Module Initialization ***************************/
749
750 #if defined(__hppa__)
751
752 static struct parisc_device_id hp_sdc_tbl[] = {
753         {
754                 .hw_type =      HPHW_FIO, 
755                 .hversion_rev = HVERSION_REV_ANY_ID,
756                 .hversion =     HVERSION_ANY_ID,
757                 .sversion =     0x73, 
758          },
759         { 0, }
760 };
761
762 MODULE_DEVICE_TABLE(parisc, hp_sdc_tbl);
763
764 static int __init hp_sdc_init_hppa(struct parisc_device *d);
765
766 static struct parisc_driver hp_sdc_driver = {
767         .name =         "HP SDC",
768         .id_table =     hp_sdc_tbl,
769         .probe =        hp_sdc_init_hppa,
770 };
771
772 #endif /* __hppa__ */
773
774 static int __init hp_sdc_init(void)
775 {
776         int i;
777         char *errstr;
778         hp_sdc_transaction t_sync;
779         uint8_t ts_sync[6];
780         struct semaphore s_sync;
781
782         rwlock_init(&hp_sdc.lock);
783         rwlock_init(&hp_sdc.ibf_lock);
784         rwlock_init(&hp_sdc.rtq_lock);
785         rwlock_init(&hp_sdc.hook_lock);
786
787         hp_sdc.timer            = NULL;
788         hp_sdc.hil              = NULL;
789         hp_sdc.pup              = NULL;
790         hp_sdc.cooked           = NULL;
791         hp_sdc.im               = HP_SDC_IM_MASK;  /* Mask maskable irqs */
792         hp_sdc.set_im           = 1;
793         hp_sdc.wi               = 0xff;
794         hp_sdc.r7[0]            = 0xff;
795         hp_sdc.r7[1]            = 0xff;
796         hp_sdc.r7[2]            = 0xff;
797         hp_sdc.r7[3]            = 0xff;
798         hp_sdc.ibf              = 1;
799
800         for (i = 0; i < HP_SDC_QUEUE_LEN; i++) hp_sdc.tq[i] = NULL;
801         hp_sdc.wcurr            = -1;
802         hp_sdc.rcurr            = -1;
803         hp_sdc.rqty             = 0;
804
805         hp_sdc.dev_err = -ENODEV;
806
807         errstr = "IO not found for";
808         if (!hp_sdc.base_io) goto err0;
809
810         errstr = "IRQ not found for";
811         if (!hp_sdc.irq) goto err0;
812
813         hp_sdc.dev_err = -EBUSY;
814
815 #if defined(__hppa__)
816         errstr = "IO not available for";
817         if (request_region(hp_sdc.data_io, 2, hp_sdc_driver.name)) goto err0;
818 #endif  
819
820         errstr = "IRQ not available for";
821         if(request_irq(hp_sdc.irq, &hp_sdc_isr, 0, "HP SDC",
822                        (void *) hp_sdc.base_io)) goto err1;
823
824         errstr = "NMI not available for";
825         if (request_irq(hp_sdc.nmi, &hp_sdc_nmisr, 0, "HP SDC NMI", 
826                         (void *) hp_sdc.base_io)) goto err2;
827
828         printk(KERN_INFO PREFIX "HP SDC at 0x%p, IRQ %d (NMI IRQ %d)\n", 
829                (void *)hp_sdc.base_io, hp_sdc.irq, hp_sdc.nmi);
830
831         hp_sdc_status_in8();
832         hp_sdc_data_in8();
833
834         tasklet_init(&hp_sdc.task, hp_sdc_tasklet, 0);
835
836         /* Sync the output buffer registers, thus scheduling hp_sdc_tasklet. */
837         t_sync.actidx   = 0;
838         t_sync.idx      = 1;
839         t_sync.endidx   = 6;
840         t_sync.seq      = ts_sync;
841         ts_sync[0]      = HP_SDC_ACT_DATAREG | HP_SDC_ACT_SEMAPHORE;
842         ts_sync[1]      = 0x0f;
843         ts_sync[2] = ts_sync[3] = ts_sync[4] = ts_sync[5] = 0;
844         t_sync.act.semaphore = &s_sync;
845         init_MUTEX_LOCKED(&s_sync);
846         hp_sdc_enqueue_transaction(&t_sync);
847         down(&s_sync); /* Wait for t_sync to complete */
848
849         /* Create the keepalive task */
850         init_timer(&hp_sdc.kicker);
851         hp_sdc.kicker.expires = jiffies + HZ;
852         hp_sdc.kicker.function = &hp_sdc_kicker;
853         add_timer(&hp_sdc.kicker);
854
855         hp_sdc.dev_err = 0;
856         return 0;
857  err2:
858         free_irq(hp_sdc.irq, NULL);
859  err1:
860         release_region(hp_sdc.data_io, 2);
861  err0:
862         printk(KERN_WARNING PREFIX ": %s SDC IO=0x%p IRQ=0x%x NMI=0x%x\n", 
863                 errstr, (void *)hp_sdc.base_io, hp_sdc.irq, hp_sdc.nmi);
864         hp_sdc.dev = NULL;
865         return hp_sdc.dev_err;
866 }
867
868 #if defined(__hppa__)
869
870 static int __init hp_sdc_init_hppa(struct parisc_device *d)
871 {
872         if (!d) return 1;
873         if (hp_sdc.dev != NULL) return 1;       /* We only expect one SDC */
874
875         hp_sdc.dev              = d;
876         hp_sdc.irq              = d->irq;
877         hp_sdc.nmi              = d->aux_irq;
878         hp_sdc.base_io          = d->hpa;
879         hp_sdc.data_io          = d->hpa + 0x800;
880         hp_sdc.status_io        = d->hpa + 0x801;
881
882         return hp_sdc_init();
883 }
884
885 #endif /* __hppa__ */
886
887 #if !defined(__mc68000__) /* Link error on m68k! */
888 static void __exit hp_sdc_exit(void)
889 #else
890 static void hp_sdc_exit(void)
891 #endif
892 {
893         write_lock_irq(&hp_sdc.lock);
894
895         /* Turn off all maskable "sub-function" irq's. */
896         hp_sdc_spin_ibf();
897         sdc_writeb(HP_SDC_CMD_SET_IM | HP_SDC_IM_MASK, hp_sdc.status_io);
898
899         /* Wait until we know this has been processed by the i8042 */
900         hp_sdc_spin_ibf();
901
902         free_irq(hp_sdc.nmi, NULL);
903         free_irq(hp_sdc.irq, NULL);
904         write_unlock_irq(&hp_sdc.lock);
905
906         del_timer(&hp_sdc.kicker);
907
908         tasklet_kill(&hp_sdc.task);
909
910 /*        release_region(hp_sdc.data_io, 2); */
911
912 #if defined(__hppa__)
913         if (unregister_parisc_driver(&hp_sdc_driver)) 
914                 printk(KERN_WARNING PREFIX "Error unregistering HP SDC");
915 #endif
916 }
917
918 static int __init hp_sdc_register(void)
919 {
920         hp_sdc_transaction tq_init;
921         uint8_t tq_init_seq[5];
922         struct semaphore tq_init_sem;
923 #if defined(__mc68000__)
924         mm_segment_t fs;
925         unsigned char i;
926 #endif
927         
928         hp_sdc.dev = NULL;
929         hp_sdc.dev_err = 0;
930 #if defined(__hppa__)
931         if (register_parisc_driver(&hp_sdc_driver)) {
932                 printk(KERN_WARNING PREFIX "Error registering SDC with system bus tree.\n");
933                 return -ENODEV;
934         }
935 #elif defined(__mc68000__)
936         if (!MACH_IS_HP300)
937             return -ENODEV;
938
939         hp_sdc.irq       = 1;
940         hp_sdc.nmi       = 7;
941         hp_sdc.base_io   = (unsigned long) 0xf0428000;
942         hp_sdc.data_io   = (unsigned long) hp_sdc.base_io + 1;
943         hp_sdc.status_io = (unsigned long) hp_sdc.base_io + 3;
944         fs = get_fs();
945         set_fs(KERNEL_DS);
946         if (!get_user(i, (unsigned char *)hp_sdc.data_io))
947                 hp_sdc.dev = (void *)1;
948         set_fs(fs);
949         hp_sdc.dev_err   = hp_sdc_init();
950 #endif
951         if (hp_sdc.dev == NULL) {
952                 printk(KERN_WARNING PREFIX "No SDC found.\n");
953                 return hp_sdc.dev_err;
954         }
955
956         init_MUTEX_LOCKED(&tq_init_sem);
957
958         tq_init.actidx          = 0;
959         tq_init.idx             = 1;
960         tq_init.endidx          = 5;
961         tq_init.seq             = tq_init_seq;
962         tq_init.act.semaphore   = &tq_init_sem;
963
964         tq_init_seq[0] = 
965           HP_SDC_ACT_POSTCMD | HP_SDC_ACT_DATAIN | HP_SDC_ACT_SEMAPHORE;
966         tq_init_seq[1] = HP_SDC_CMD_READ_KCC;
967         tq_init_seq[2] = 1;
968         tq_init_seq[3] = 0;
969         tq_init_seq[4] = 0;
970
971         hp_sdc_enqueue_transaction(&tq_init);
972
973         down(&tq_init_sem);
974         up(&tq_init_sem);
975
976         if ((tq_init_seq[0] & HP_SDC_ACT_DEAD) == HP_SDC_ACT_DEAD) {
977                 printk(KERN_WARNING PREFIX "Error reading config byte.\n");
978                 hp_sdc_exit();
979                 return -ENODEV;
980         }
981         hp_sdc.r11 = tq_init_seq[4];
982         if (hp_sdc.r11 & HP_SDC_CFG_NEW) {
983                 char *str;
984                 printk(KERN_INFO PREFIX "New style SDC\n");
985                 tq_init_seq[1] = HP_SDC_CMD_READ_XTD;
986                 tq_init.actidx          = 0;
987                 tq_init.idx             = 1;
988                 down(&tq_init_sem);
989                 hp_sdc_enqueue_transaction(&tq_init);           
990                 down(&tq_init_sem);
991                 up(&tq_init_sem);
992                 if ((tq_init_seq[0] & HP_SDC_ACT_DEAD) == HP_SDC_ACT_DEAD) {
993                         printk(KERN_WARNING PREFIX "Error reading extended config byte.\n");
994                         return -ENODEV;
995                 }
996                 hp_sdc.r7e = tq_init_seq[4];
997                 HP_SDC_XTD_REV_STRINGS(hp_sdc.r7e & HP_SDC_XTD_REV, str)
998                 printk(KERN_INFO PREFIX "Revision: %s\n", str);
999                 if (hp_sdc.r7e & HP_SDC_XTD_BEEPER) {
1000                         printk(KERN_INFO PREFIX "TI SN76494 beeper present\n");
1001                 }
1002                 if (hp_sdc.r7e & HP_SDC_XTD_BBRTC) {
1003                         printk(KERN_INFO PREFIX "OKI MSM-58321 BBRTC present\n");
1004                 }
1005                 printk(KERN_INFO PREFIX "Spunking the self test register to force PUP "
1006                        "on next firmware reset.\n");
1007                 tq_init_seq[0] = HP_SDC_ACT_PRECMD | 
1008                         HP_SDC_ACT_DATAOUT | HP_SDC_ACT_SEMAPHORE;
1009                 tq_init_seq[1] = HP_SDC_CMD_SET_STR;
1010                 tq_init_seq[2] = 1;
1011                 tq_init_seq[3] = 0;
1012                 tq_init.actidx          = 0;
1013                 tq_init.idx             = 1;
1014                 tq_init.endidx          = 4;
1015                 down(&tq_init_sem);
1016                 hp_sdc_enqueue_transaction(&tq_init);           
1017                 down(&tq_init_sem);
1018                 up(&tq_init_sem);
1019         }
1020         else {
1021                 printk(KERN_INFO PREFIX "Old style SDC (1820-%s).\n", 
1022                        (hp_sdc.r11 & HP_SDC_CFG_REV) ? "3300" : "2564/3087");
1023         }
1024
1025         return 0;
1026 }
1027
1028 module_init(hp_sdc_register);
1029 module_exit(hp_sdc_exit);
1030
1031 /* Timing notes:  These measurements taken on my 64MHz 7100-LC (715/64) 
1032  *                                              cycles cycles-adj    time
1033  * between two consecutive mfctl(16)'s:              4        n/a    63ns
1034  * hp_sdc_spin_ibf when idle:                      119        115   1.7us
1035  * gsc_writeb status register:                      83         79   1.2us
1036  * IBF to clear after sending SET_IM:             6204       6006    93us
1037  * IBF to clear after sending LOAD_RT:            4467       4352    68us  
1038  * IBF to clear after sending two LOAD_RTs:      18974      18859   295us
1039  * READ_T1, read status/data, IRQ, call handler: 35564        n/a   556us
1040  * cmd to ~IBF READ_T1 2nd time right after:   5158403        n/a    81ms
1041  * between IRQ received and ~IBF for above:    2578877        n/a    40ms
1042  *
1043  * Performance stats after a run of this module configuring HIL and
1044  * receiving a few mouse events:
1045  *
1046  * status in8  282508 cycles 7128 calls
1047  * status out8   8404 cycles  341 calls
1048  * data out8     1734 cycles   78 calls
1049  * isr         174324 cycles  617 calls (includes take)
1050  * take          1241 cycles    2 calls
1051  * put        1411504 cycles 6937 calls
1052  * task       1655209 cycles 6937 calls (includes put)
1053  *
1054  */