Merge branch 'timers-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel...
[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/errno.h>
66 #include <linux/init.h>
67 #include <linux/module.h>
68 #include <linux/ioport.h>
69 #include <linux/time.h>
70 #include <linux/semaphore.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_enqueue_transaction);
106 EXPORT_SYMBOL(hp_sdc_dequeue_transaction);
107
108 static unsigned int hp_sdc_disabled;
109 module_param_named(no_hpsdc, hp_sdc_disabled, bool, 0);
110 MODULE_PARM_DESC(no_hpsdc, "Do not enable HP SDC driver.");
111
112 static hp_i8042_sdc     hp_sdc; /* All driver state is kept in here. */
113
114 /*************** primitives for use in any context *********************/
115 static inline uint8_t hp_sdc_status_in8(void)
116 {
117         uint8_t status;
118         unsigned long flags;
119
120         write_lock_irqsave(&hp_sdc.ibf_lock, flags);
121         status = sdc_readb(hp_sdc.status_io);
122         if (!(status & HP_SDC_STATUS_IBF))
123                 hp_sdc.ibf = 0;
124         write_unlock_irqrestore(&hp_sdc.ibf_lock, flags);
125
126         return status;
127 }
128
129 static inline uint8_t hp_sdc_data_in8(void)
130 {
131         return sdc_readb(hp_sdc.data_io);
132 }
133
134 static inline void hp_sdc_status_out8(uint8_t val)
135 {
136         unsigned long flags;
137
138         write_lock_irqsave(&hp_sdc.ibf_lock, flags);
139         hp_sdc.ibf = 1;
140         if ((val & 0xf0) == 0xe0)
141                 hp_sdc.wi = 0xff;
142         sdc_writeb(val, hp_sdc.status_io);
143         write_unlock_irqrestore(&hp_sdc.ibf_lock, flags);
144 }
145
146 static inline void hp_sdc_data_out8(uint8_t val)
147 {
148         unsigned long flags;
149
150         write_lock_irqsave(&hp_sdc.ibf_lock, flags);
151         hp_sdc.ibf = 1;
152         sdc_writeb(val, hp_sdc.data_io);
153         write_unlock_irqrestore(&hp_sdc.ibf_lock, flags);
154 }
155
156 /*      Care must be taken to only invoke hp_sdc_spin_ibf when
157  *      absolutely needed, or in rarely invoked subroutines.
158  *      Not only does it waste CPU cycles, it also wastes bus cycles.
159  */
160 static inline void hp_sdc_spin_ibf(void)
161 {
162         unsigned long flags;
163         rwlock_t *lock;
164
165         lock = &hp_sdc.ibf_lock;
166
167         read_lock_irqsave(lock, flags);
168         if (!hp_sdc.ibf) {
169                 read_unlock_irqrestore(lock, flags);
170                 return;
171         }
172         read_unlock(lock);
173         write_lock(lock);
174         while (sdc_readb(hp_sdc.status_io) & HP_SDC_STATUS_IBF)
175                 { }
176         hp_sdc.ibf = 0;
177         write_unlock_irqrestore(lock, flags);
178 }
179
180
181 /************************ Interrupt context functions ************************/
182 static void hp_sdc_take(int irq, void *dev_id, uint8_t status, uint8_t data)
183 {
184         hp_sdc_transaction *curr;
185
186         read_lock(&hp_sdc.rtq_lock);
187         if (hp_sdc.rcurr < 0) {
188                 read_unlock(&hp_sdc.rtq_lock);
189                 return;
190         }
191         curr = hp_sdc.tq[hp_sdc.rcurr];
192         read_unlock(&hp_sdc.rtq_lock);
193
194         curr->seq[curr->idx++] = status;
195         curr->seq[curr->idx++] = data;
196         hp_sdc.rqty -= 2;
197         do_gettimeofday(&hp_sdc.rtv);
198
199         if (hp_sdc.rqty <= 0) {
200                 /* All data has been gathered. */
201                 if (curr->seq[curr->actidx] & HP_SDC_ACT_SEMAPHORE)
202                         if (curr->act.semaphore)
203                                 up(curr->act.semaphore);
204
205                 if (curr->seq[curr->actidx] & HP_SDC_ACT_CALLBACK)
206                         if (curr->act.irqhook)
207                                 curr->act.irqhook(irq, dev_id, status, data);
208
209                 curr->actidx = curr->idx;
210                 curr->idx++;
211                 /* Return control of this transaction */
212                 write_lock(&hp_sdc.rtq_lock);
213                 hp_sdc.rcurr = -1;
214                 hp_sdc.rqty = 0;
215                 write_unlock(&hp_sdc.rtq_lock);
216                 tasklet_schedule(&hp_sdc.task);
217         }
218 }
219
220 static irqreturn_t hp_sdc_isr(int irq, void *dev_id)
221 {
222         uint8_t status, data;
223
224         status = hp_sdc_status_in8();
225         /* Read data unconditionally to advance i8042. */
226         data =   hp_sdc_data_in8();
227
228         /* For now we are ignoring these until we get the SDC to behave. */
229         if (((status & 0xf1) == 0x51) && data == 0x82)
230                 return IRQ_HANDLED;
231
232         switch (status & HP_SDC_STATUS_IRQMASK) {
233         case 0: /* This case is not documented. */
234                 break;
235
236         case HP_SDC_STATUS_USERTIMER:
237         case HP_SDC_STATUS_PERIODIC:
238         case HP_SDC_STATUS_TIMER:
239                 read_lock(&hp_sdc.hook_lock);
240                 if (hp_sdc.timer != NULL)
241                         hp_sdc.timer(irq, dev_id, status, data);
242                 read_unlock(&hp_sdc.hook_lock);
243                 break;
244
245         case HP_SDC_STATUS_REG:
246                 hp_sdc_take(irq, dev_id, status, data);
247                 break;
248
249         case HP_SDC_STATUS_HILCMD:
250         case HP_SDC_STATUS_HILDATA:
251                 read_lock(&hp_sdc.hook_lock);
252                 if (hp_sdc.hil != NULL)
253                         hp_sdc.hil(irq, dev_id, status, data);
254                 read_unlock(&hp_sdc.hook_lock);
255                 break;
256
257         case HP_SDC_STATUS_PUP:
258                 read_lock(&hp_sdc.hook_lock);
259                 if (hp_sdc.pup != NULL)
260                         hp_sdc.pup(irq, dev_id, status, data);
261                 else
262                         printk(KERN_INFO PREFIX "HP SDC reports successful PUP.\n");
263                 read_unlock(&hp_sdc.hook_lock);
264                 break;
265
266         default:
267                 read_lock(&hp_sdc.hook_lock);
268                 if (hp_sdc.cooked != NULL)
269                         hp_sdc.cooked(irq, dev_id, status, data);
270                 read_unlock(&hp_sdc.hook_lock);
271                 break;
272         }
273
274         return IRQ_HANDLED;
275 }
276
277
278 static irqreturn_t hp_sdc_nmisr(int irq, void *dev_id)
279 {
280         int status;
281
282         status = hp_sdc_status_in8();
283         printk(KERN_WARNING PREFIX "NMI !\n");
284
285 #if 0
286         if (status & HP_SDC_NMISTATUS_FHS) {
287                 read_lock(&hp_sdc.hook_lock);
288                 if (hp_sdc.timer != NULL)
289                         hp_sdc.timer(irq, dev_id, status, 0);
290                 read_unlock(&hp_sdc.hook_lock);
291         } else {
292                 /* TODO: pass this on to the HIL handler, or do SAK here? */
293                 printk(KERN_WARNING PREFIX "HIL NMI\n");
294         }
295 #endif
296
297         return IRQ_HANDLED;
298 }
299
300
301 /***************** Kernel (tasklet) context functions ****************/
302
303 unsigned long hp_sdc_put(void);
304
305 static void hp_sdc_tasklet(unsigned long foo)
306 {
307         write_lock_irq(&hp_sdc.rtq_lock);
308
309         if (hp_sdc.rcurr >= 0) {
310                 struct timeval tv;
311
312                 do_gettimeofday(&tv);
313                 if (tv.tv_sec > hp_sdc.rtv.tv_sec)
314                         tv.tv_usec += USEC_PER_SEC;
315
316                 if (tv.tv_usec - hp_sdc.rtv.tv_usec > HP_SDC_MAX_REG_DELAY) {
317                         hp_sdc_transaction *curr;
318                         uint8_t tmp;
319
320                         curr = hp_sdc.tq[hp_sdc.rcurr];
321                         /* If this turns out to be a normal failure mode
322                          * we'll need to figure out a way to communicate
323                          * it back to the application. and be less verbose.
324                          */
325                         printk(KERN_WARNING PREFIX "read timeout (%ius)!\n",
326                                tv.tv_usec - hp_sdc.rtv.tv_usec);
327                         curr->idx += hp_sdc.rqty;
328                         hp_sdc.rqty = 0;
329                         tmp = curr->seq[curr->actidx];
330                         curr->seq[curr->actidx] |= HP_SDC_ACT_DEAD;
331                         if (tmp & HP_SDC_ACT_SEMAPHORE)
332                                 if (curr->act.semaphore)
333                                         up(curr->act.semaphore);
334
335                         if (tmp & HP_SDC_ACT_CALLBACK) {
336                                 /* Note this means that irqhooks may be called
337                                  * in tasklet/bh context.
338                                  */
339                                 if (curr->act.irqhook)
340                                         curr->act.irqhook(0, NULL, 0, 0);
341                         }
342
343                         curr->actidx = curr->idx;
344                         curr->idx++;
345                         hp_sdc.rcurr = -1;
346                 }
347         }
348         write_unlock_irq(&hp_sdc.rtq_lock);
349         hp_sdc_put();
350 }
351
352 unsigned long hp_sdc_put(void)
353 {
354         hp_sdc_transaction *curr;
355         uint8_t act;
356         int idx, curridx;
357
358         int limit = 0;
359
360         write_lock(&hp_sdc.lock);
361
362         /* If i8042 buffers are full, we cannot do anything that
363            requires output, so we skip to the administrativa. */
364         if (hp_sdc.ibf) {
365                 hp_sdc_status_in8();
366                 if (hp_sdc.ibf)
367                         goto finish;
368         }
369
370  anew:
371         /* See if we are in the middle of a sequence. */
372         if (hp_sdc.wcurr < 0)
373                 hp_sdc.wcurr = 0;
374         read_lock_irq(&hp_sdc.rtq_lock);
375         if (hp_sdc.rcurr == hp_sdc.wcurr)
376                 hp_sdc.wcurr++;
377         read_unlock_irq(&hp_sdc.rtq_lock);
378         if (hp_sdc.wcurr >= HP_SDC_QUEUE_LEN)
379                 hp_sdc.wcurr = 0;
380         curridx = hp_sdc.wcurr;
381
382         if (hp_sdc.tq[curridx] != NULL)
383                 goto start;
384
385         while (++curridx != hp_sdc.wcurr) {
386                 if (curridx >= HP_SDC_QUEUE_LEN) {
387                         curridx = -1; /* Wrap to top */
388                         continue;
389                 }
390                 read_lock_irq(&hp_sdc.rtq_lock);
391                 if (hp_sdc.rcurr == curridx) {
392                         read_unlock_irq(&hp_sdc.rtq_lock);
393                         continue;
394                 }
395                 read_unlock_irq(&hp_sdc.rtq_lock);
396                 if (hp_sdc.tq[curridx] != NULL)
397                         break; /* Found one. */
398         }
399         if (curridx == hp_sdc.wcurr) { /* There's nothing queued to do. */
400                 curridx = -1;
401         }
402         hp_sdc.wcurr = curridx;
403
404  start:
405
406         /* Check to see if the interrupt mask needs to be set. */
407         if (hp_sdc.set_im) {
408                 hp_sdc_status_out8(hp_sdc.im | HP_SDC_CMD_SET_IM);
409                 hp_sdc.set_im = 0;
410                 goto finish;
411         }
412
413         if (hp_sdc.wcurr == -1)
414                 goto done;
415
416         curr = hp_sdc.tq[curridx];
417         idx = curr->actidx;
418
419         if (curr->actidx >= curr->endidx) {
420                 hp_sdc.tq[curridx] = NULL;
421                 /* Interleave outbound data between the transactions. */
422                 hp_sdc.wcurr++;
423                 if (hp_sdc.wcurr >= HP_SDC_QUEUE_LEN)
424                         hp_sdc.wcurr = 0;
425                 goto finish;
426         }
427
428         act = curr->seq[idx];
429         idx++;
430
431         if (curr->idx >= curr->endidx) {
432                 if (act & HP_SDC_ACT_DEALLOC)
433                         kfree(curr);
434                 hp_sdc.tq[curridx] = NULL;
435                 /* Interleave outbound data between the transactions. */
436                 hp_sdc.wcurr++;
437                 if (hp_sdc.wcurr >= HP_SDC_QUEUE_LEN)
438                         hp_sdc.wcurr = 0;
439                 goto finish;
440         }
441
442         while (act & HP_SDC_ACT_PRECMD) {
443                 if (curr->idx != idx) {
444                         idx++;
445                         act &= ~HP_SDC_ACT_PRECMD;
446                         break;
447                 }
448                 hp_sdc_status_out8(curr->seq[idx]);
449                 curr->idx++;
450                 /* act finished? */
451                 if ((act & HP_SDC_ACT_DURING) == HP_SDC_ACT_PRECMD)
452                         goto actdone;
453                 /* skip quantity field if data-out sequence follows. */
454                 if (act & HP_SDC_ACT_DATAOUT)
455                         curr->idx++;
456                 goto finish;
457         }
458         if (act & HP_SDC_ACT_DATAOUT) {
459                 int qty;
460
461                 qty = curr->seq[idx];
462                 idx++;
463                 if (curr->idx - idx < qty) {
464                         hp_sdc_data_out8(curr->seq[curr->idx]);
465                         curr->idx++;
466                         /* act finished? */
467                         if (curr->idx - idx >= qty &&
468                             (act & HP_SDC_ACT_DURING) == HP_SDC_ACT_DATAOUT)
469                                 goto actdone;
470                         goto finish;
471                 }
472                 idx += qty;
473                 act &= ~HP_SDC_ACT_DATAOUT;
474         } else
475             while (act & HP_SDC_ACT_DATAREG) {
476                 int mask;
477                 uint8_t w7[4];
478
479                 mask = curr->seq[idx];
480                 if (idx != curr->idx) {
481                         idx++;
482                         idx += !!(mask & 1);
483                         idx += !!(mask & 2);
484                         idx += !!(mask & 4);
485                         idx += !!(mask & 8);
486                         act &= ~HP_SDC_ACT_DATAREG;
487                         break;
488                 }
489
490                 w7[0] = (mask & 1) ? curr->seq[++idx] : hp_sdc.r7[0];
491                 w7[1] = (mask & 2) ? curr->seq[++idx] : hp_sdc.r7[1];
492                 w7[2] = (mask & 4) ? curr->seq[++idx] : hp_sdc.r7[2];
493                 w7[3] = (mask & 8) ? curr->seq[++idx] : hp_sdc.r7[3];
494
495                 if (hp_sdc.wi > 0x73 || hp_sdc.wi < 0x70 ||
496                     w7[hp_sdc.wi - 0x70] == hp_sdc.r7[hp_sdc.wi - 0x70]) {
497                         int i = 0;
498
499                         /* Need to point the write index register */
500                         while (i < 4 && w7[i] == hp_sdc.r7[i])
501                                 i++;
502
503                         if (i < 4) {
504                                 hp_sdc_status_out8(HP_SDC_CMD_SET_D0 + i);
505                                 hp_sdc.wi = 0x70 + i;
506                                 goto finish;
507                         }
508
509                         idx++;
510                         if ((act & HP_SDC_ACT_DURING) == HP_SDC_ACT_DATAREG)
511                                 goto actdone;
512
513                         curr->idx = idx;
514                         act &= ~HP_SDC_ACT_DATAREG;
515                         break;
516                 }
517
518                 hp_sdc_data_out8(w7[hp_sdc.wi - 0x70]);
519                 hp_sdc.r7[hp_sdc.wi - 0x70] = w7[hp_sdc.wi - 0x70];
520                 hp_sdc.wi++; /* write index register autoincrements */
521                 {
522                         int i = 0;
523
524                         while ((i < 4) && w7[i] == hp_sdc.r7[i])
525                                 i++;
526                         if (i >= 4) {
527                                 curr->idx = idx + 1;
528                                 if ((act & HP_SDC_ACT_DURING) ==
529                                     HP_SDC_ACT_DATAREG)
530                                         goto actdone;
531                         }
532                 }
533                 goto finish;
534         }
535         /* We don't go any further in the command if there is a pending read,
536            because we don't want interleaved results. */
537         read_lock_irq(&hp_sdc.rtq_lock);
538         if (hp_sdc.rcurr >= 0) {
539                 read_unlock_irq(&hp_sdc.rtq_lock);
540                 goto finish;
541         }
542         read_unlock_irq(&hp_sdc.rtq_lock);
543
544
545         if (act & HP_SDC_ACT_POSTCMD) {
546                 uint8_t postcmd;
547
548                 /* curr->idx should == idx at this point. */
549                 postcmd = curr->seq[idx];
550                 curr->idx++;
551                 if (act & HP_SDC_ACT_DATAIN) {
552
553                         /* Start a new read */
554                         hp_sdc.rqty = curr->seq[curr->idx];
555                         do_gettimeofday(&hp_sdc.rtv);
556                         curr->idx++;
557                         /* Still need to lock here in case of spurious irq. */
558                         write_lock_irq(&hp_sdc.rtq_lock);
559                         hp_sdc.rcurr = curridx;
560                         write_unlock_irq(&hp_sdc.rtq_lock);
561                         hp_sdc_status_out8(postcmd);
562                         goto finish;
563                 }
564                 hp_sdc_status_out8(postcmd);
565                 goto actdone;
566         }
567
568  actdone:
569         if (act & HP_SDC_ACT_SEMAPHORE)
570                 up(curr->act.semaphore);
571         else if (act & HP_SDC_ACT_CALLBACK)
572                 curr->act.irqhook(0,NULL,0,0);
573
574         if (curr->idx >= curr->endidx) { /* This transaction is over. */
575                 if (act & HP_SDC_ACT_DEALLOC)
576                         kfree(curr);
577                 hp_sdc.tq[curridx] = NULL;
578         } else {
579                 curr->actidx = idx + 1;
580                 curr->idx = idx + 2;
581         }
582         /* Interleave outbound data between the transactions. */
583         hp_sdc.wcurr++;
584         if (hp_sdc.wcurr >= HP_SDC_QUEUE_LEN)
585                 hp_sdc.wcurr = 0;
586
587  finish:
588         /* If by some quirk IBF has cleared and our ISR has run to
589            see that that has happened, do it all again. */
590         if (!hp_sdc.ibf && limit++ < 20)
591                 goto anew;
592
593  done:
594         if (hp_sdc.wcurr >= 0)
595                 tasklet_schedule(&hp_sdc.task);
596         write_unlock(&hp_sdc.lock);
597
598         return 0;
599 }
600
601 /******* Functions called in either user or kernel context ****/
602 int __hp_sdc_enqueue_transaction(hp_sdc_transaction *this)
603 {
604         int i;
605
606         if (this == NULL) {
607                 BUG();
608                 return -EINVAL;
609         }
610
611         /* Can't have same transaction on queue twice */
612         for (i = 0; i < HP_SDC_QUEUE_LEN; i++)
613                 if (hp_sdc.tq[i] == this)
614                         goto fail;
615
616         this->actidx = 0;
617         this->idx = 1;
618
619         /* Search for empty slot */
620         for (i = 0; i < HP_SDC_QUEUE_LEN; i++)
621                 if (hp_sdc.tq[i] == NULL) {
622                         hp_sdc.tq[i] = this;
623                         tasklet_schedule(&hp_sdc.task);
624                         return 0;
625                 }
626
627         printk(KERN_WARNING PREFIX "No free slot to add transaction.\n");
628         return -EBUSY;
629
630  fail:
631         printk(KERN_WARNING PREFIX "Transaction add failed: transaction already queued?\n");
632         return -EINVAL;
633 }
634
635 int hp_sdc_enqueue_transaction(hp_sdc_transaction *this) {
636         unsigned long flags;
637         int ret;
638
639         write_lock_irqsave(&hp_sdc.lock, flags);
640         ret = __hp_sdc_enqueue_transaction(this);
641         write_unlock_irqrestore(&hp_sdc.lock,flags);
642
643         return ret;
644 }
645
646 int hp_sdc_dequeue_transaction(hp_sdc_transaction *this)
647 {
648         unsigned long flags;
649         int i;
650
651         write_lock_irqsave(&hp_sdc.lock, flags);
652
653         /* TODO: don't remove it if it's not done. */
654
655         for (i = 0; i < HP_SDC_QUEUE_LEN; i++)
656                 if (hp_sdc.tq[i] == this)
657                         hp_sdc.tq[i] = NULL;
658
659         write_unlock_irqrestore(&hp_sdc.lock, flags);
660         return 0;
661 }
662
663
664
665 /********************** User context functions **************************/
666 int hp_sdc_request_timer_irq(hp_sdc_irqhook *callback)
667 {
668         if (callback == NULL || hp_sdc.dev == NULL)
669                 return -EINVAL;
670
671         write_lock_irq(&hp_sdc.hook_lock);
672         if (hp_sdc.timer != NULL) {
673                 write_unlock_irq(&hp_sdc.hook_lock);
674                 return -EBUSY;
675         }
676
677         hp_sdc.timer = callback;
678         /* Enable interrupts from the timers */
679         hp_sdc.im &= ~HP_SDC_IM_FH;
680         hp_sdc.im &= ~HP_SDC_IM_PT;
681         hp_sdc.im &= ~HP_SDC_IM_TIMERS;
682         hp_sdc.set_im = 1;
683         write_unlock_irq(&hp_sdc.hook_lock);
684
685         tasklet_schedule(&hp_sdc.task);
686
687         return 0;
688 }
689
690 int hp_sdc_request_hil_irq(hp_sdc_irqhook *callback)
691 {
692         if (callback == NULL || hp_sdc.dev == NULL)
693                 return -EINVAL;
694
695         write_lock_irq(&hp_sdc.hook_lock);
696         if (hp_sdc.hil != NULL) {
697                 write_unlock_irq(&hp_sdc.hook_lock);
698                 return -EBUSY;
699         }
700
701         hp_sdc.hil = callback;
702         hp_sdc.im &= ~(HP_SDC_IM_HIL | HP_SDC_IM_RESET);
703         hp_sdc.set_im = 1;
704         write_unlock_irq(&hp_sdc.hook_lock);
705
706         tasklet_schedule(&hp_sdc.task);
707
708         return 0;
709 }
710
711 int hp_sdc_request_cooked_irq(hp_sdc_irqhook *callback)
712 {
713         if (callback == NULL || hp_sdc.dev == NULL)
714                 return -EINVAL;
715
716         write_lock_irq(&hp_sdc.hook_lock);
717         if (hp_sdc.cooked != NULL) {
718                 write_unlock_irq(&hp_sdc.hook_lock);
719                 return -EBUSY;
720         }
721
722         /* Enable interrupts from the HIL MLC */
723         hp_sdc.cooked = callback;
724         hp_sdc.im &= ~(HP_SDC_IM_HIL | HP_SDC_IM_RESET);
725         hp_sdc.set_im = 1;
726         write_unlock_irq(&hp_sdc.hook_lock);
727
728         tasklet_schedule(&hp_sdc.task);
729
730         return 0;
731 }
732
733 int hp_sdc_release_timer_irq(hp_sdc_irqhook *callback)
734 {
735         write_lock_irq(&hp_sdc.hook_lock);
736         if ((callback != hp_sdc.timer) ||
737             (hp_sdc.timer == NULL)) {
738                 write_unlock_irq(&hp_sdc.hook_lock);
739                 return -EINVAL;
740         }
741
742         /* Disable interrupts from the timers */
743         hp_sdc.timer = NULL;
744         hp_sdc.im |= HP_SDC_IM_TIMERS;
745         hp_sdc.im |= HP_SDC_IM_FH;
746         hp_sdc.im |= HP_SDC_IM_PT;
747         hp_sdc.set_im = 1;
748         write_unlock_irq(&hp_sdc.hook_lock);
749         tasklet_schedule(&hp_sdc.task);
750
751         return 0;
752 }
753
754 int hp_sdc_release_hil_irq(hp_sdc_irqhook *callback)
755 {
756         write_lock_irq(&hp_sdc.hook_lock);
757         if ((callback != hp_sdc.hil) ||
758             (hp_sdc.hil == NULL)) {
759                 write_unlock_irq(&hp_sdc.hook_lock);
760                 return -EINVAL;
761         }
762
763         hp_sdc.hil = NULL;
764         /* Disable interrupts from HIL only if there is no cooked driver. */
765         if(hp_sdc.cooked == NULL) {
766                 hp_sdc.im |= (HP_SDC_IM_HIL | HP_SDC_IM_RESET);
767                 hp_sdc.set_im = 1;
768         }
769         write_unlock_irq(&hp_sdc.hook_lock);
770         tasklet_schedule(&hp_sdc.task);
771
772         return 0;
773 }
774
775 int hp_sdc_release_cooked_irq(hp_sdc_irqhook *callback)
776 {
777         write_lock_irq(&hp_sdc.hook_lock);
778         if ((callback != hp_sdc.cooked) ||
779             (hp_sdc.cooked == NULL)) {
780                 write_unlock_irq(&hp_sdc.hook_lock);
781                 return -EINVAL;
782         }
783
784         hp_sdc.cooked = NULL;
785         /* Disable interrupts from HIL only if there is no raw HIL driver. */
786         if(hp_sdc.hil == NULL) {
787                 hp_sdc.im |= (HP_SDC_IM_HIL | HP_SDC_IM_RESET);
788                 hp_sdc.set_im = 1;
789         }
790         write_unlock_irq(&hp_sdc.hook_lock);
791         tasklet_schedule(&hp_sdc.task);
792
793         return 0;
794 }
795
796 /************************* Keepalive timer task *********************/
797
798 void hp_sdc_kicker (unsigned long data)
799 {
800         tasklet_schedule(&hp_sdc.task);
801         /* Re-insert the periodic task. */
802         mod_timer(&hp_sdc.kicker, jiffies + HZ);
803 }
804
805 /************************** Module Initialization ***************************/
806
807 #if defined(__hppa__)
808
809 static const struct parisc_device_id hp_sdc_tbl[] = {
810         {
811                 .hw_type =      HPHW_FIO,
812                 .hversion_rev = HVERSION_REV_ANY_ID,
813                 .hversion =     HVERSION_ANY_ID,
814                 .sversion =     0x73,
815          },
816         { 0, }
817 };
818
819 MODULE_DEVICE_TABLE(parisc, hp_sdc_tbl);
820
821 static int __init hp_sdc_init_hppa(struct parisc_device *d);
822
823 static struct parisc_driver hp_sdc_driver = {
824         .name =         "hp_sdc",
825         .id_table =     hp_sdc_tbl,
826         .probe =        hp_sdc_init_hppa,
827 };
828
829 #endif /* __hppa__ */
830
831 static int __init hp_sdc_init(void)
832 {
833         char *errstr;
834         hp_sdc_transaction t_sync;
835         uint8_t ts_sync[6];
836         struct semaphore s_sync;
837
838         rwlock_init(&hp_sdc.lock);
839         rwlock_init(&hp_sdc.ibf_lock);
840         rwlock_init(&hp_sdc.rtq_lock);
841         rwlock_init(&hp_sdc.hook_lock);
842
843         hp_sdc.timer            = NULL;
844         hp_sdc.hil              = NULL;
845         hp_sdc.pup              = NULL;
846         hp_sdc.cooked           = NULL;
847         hp_sdc.im               = HP_SDC_IM_MASK;  /* Mask maskable irqs */
848         hp_sdc.set_im           = 1;
849         hp_sdc.wi               = 0xff;
850         hp_sdc.r7[0]            = 0xff;
851         hp_sdc.r7[1]            = 0xff;
852         hp_sdc.r7[2]            = 0xff;
853         hp_sdc.r7[3]            = 0xff;
854         hp_sdc.ibf              = 1;
855
856         memset(&hp_sdc.tq, 0, sizeof(hp_sdc.tq));
857
858         hp_sdc.wcurr            = -1;
859         hp_sdc.rcurr            = -1;
860         hp_sdc.rqty             = 0;
861
862         hp_sdc.dev_err = -ENODEV;
863
864         errstr = "IO not found for";
865         if (!hp_sdc.base_io)
866                 goto err0;
867
868         errstr = "IRQ not found for";
869         if (!hp_sdc.irq)
870                 goto err0;
871
872         hp_sdc.dev_err = -EBUSY;
873
874 #if defined(__hppa__)
875         errstr = "IO not available for";
876         if (request_region(hp_sdc.data_io, 2, hp_sdc_driver.name))
877                 goto err0;
878 #endif
879
880         errstr = "IRQ not available for";
881         if (request_irq(hp_sdc.irq, &hp_sdc_isr, IRQF_SHARED|IRQF_SAMPLE_RANDOM,
882                         "HP SDC", &hp_sdc))
883                 goto err1;
884
885         errstr = "NMI not available for";
886         if (request_irq(hp_sdc.nmi, &hp_sdc_nmisr, IRQF_SHARED,
887                         "HP SDC NMI", &hp_sdc))
888                 goto err2;
889
890         printk(KERN_INFO PREFIX "HP SDC at 0x%p, IRQ %d (NMI IRQ %d)\n",
891                (void *)hp_sdc.base_io, hp_sdc.irq, hp_sdc.nmi);
892
893         hp_sdc_status_in8();
894         hp_sdc_data_in8();
895
896         tasklet_init(&hp_sdc.task, hp_sdc_tasklet, 0);
897
898         /* Sync the output buffer registers, thus scheduling hp_sdc_tasklet. */
899         t_sync.actidx   = 0;
900         t_sync.idx      = 1;
901         t_sync.endidx   = 6;
902         t_sync.seq      = ts_sync;
903         ts_sync[0]      = HP_SDC_ACT_DATAREG | HP_SDC_ACT_SEMAPHORE;
904         ts_sync[1]      = 0x0f;
905         ts_sync[2] = ts_sync[3] = ts_sync[4] = ts_sync[5] = 0;
906         t_sync.act.semaphore = &s_sync;
907         init_MUTEX_LOCKED(&s_sync);
908         hp_sdc_enqueue_transaction(&t_sync);
909         down(&s_sync); /* Wait for t_sync to complete */
910
911         /* Create the keepalive task */
912         init_timer(&hp_sdc.kicker);
913         hp_sdc.kicker.expires = jiffies + HZ;
914         hp_sdc.kicker.function = &hp_sdc_kicker;
915         add_timer(&hp_sdc.kicker);
916
917         hp_sdc.dev_err = 0;
918         return 0;
919  err2:
920         free_irq(hp_sdc.irq, &hp_sdc);
921  err1:
922         release_region(hp_sdc.data_io, 2);
923  err0:
924         printk(KERN_WARNING PREFIX ": %s SDC IO=0x%p IRQ=0x%x NMI=0x%x\n",
925                 errstr, (void *)hp_sdc.base_io, hp_sdc.irq, hp_sdc.nmi);
926         hp_sdc.dev = NULL;
927
928         return hp_sdc.dev_err;
929 }
930
931 #if defined(__hppa__)
932
933 static int __init hp_sdc_init_hppa(struct parisc_device *d)
934 {
935         if (!d)
936                 return 1;
937         if (hp_sdc.dev != NULL)
938                 return 1;       /* We only expect one SDC */
939
940         hp_sdc.dev              = d;
941         hp_sdc.irq              = d->irq;
942         hp_sdc.nmi              = d->aux_irq;
943         hp_sdc.base_io          = d->hpa.start;
944         hp_sdc.data_io          = d->hpa.start + 0x800;
945         hp_sdc.status_io        = d->hpa.start + 0x801;
946
947         return hp_sdc_init();
948 }
949
950 #endif /* __hppa__ */
951
952 static void hp_sdc_exit(void)
953 {
954         write_lock_irq(&hp_sdc.lock);
955
956         /* Turn off all maskable "sub-function" irq's. */
957         hp_sdc_spin_ibf();
958         sdc_writeb(HP_SDC_CMD_SET_IM | HP_SDC_IM_MASK, hp_sdc.status_io);
959
960         /* Wait until we know this has been processed by the i8042 */
961         hp_sdc_spin_ibf();
962
963         free_irq(hp_sdc.nmi, &hp_sdc);
964         free_irq(hp_sdc.irq, &hp_sdc);
965         write_unlock_irq(&hp_sdc.lock);
966
967         del_timer(&hp_sdc.kicker);
968
969         tasklet_kill(&hp_sdc.task);
970
971 #if defined(__hppa__)
972         if (unregister_parisc_driver(&hp_sdc_driver))
973                 printk(KERN_WARNING PREFIX "Error unregistering HP SDC");
974 #endif
975 }
976
977 static int __init hp_sdc_register(void)
978 {
979         hp_sdc_transaction tq_init;
980         uint8_t tq_init_seq[5];
981         struct semaphore tq_init_sem;
982 #if defined(__mc68000__)
983         mm_segment_t fs;
984         unsigned char i;
985 #endif
986
987         if (hp_sdc_disabled) {
988                 printk(KERN_WARNING PREFIX "HP SDC driver disabled by no_hpsdc=1.\n");
989                 return -ENODEV;
990         }
991
992         hp_sdc.dev = NULL;
993         hp_sdc.dev_err = 0;
994 #if defined(__hppa__)
995         if (register_parisc_driver(&hp_sdc_driver)) {
996                 printk(KERN_WARNING PREFIX "Error registering SDC with system bus tree.\n");
997                 return -ENODEV;
998         }
999 #elif defined(__mc68000__)
1000         if (!MACH_IS_HP300)
1001             return -ENODEV;
1002
1003         hp_sdc.irq       = 1;
1004         hp_sdc.nmi       = 7;
1005         hp_sdc.base_io   = (unsigned long) 0xf0428000;
1006         hp_sdc.data_io   = (unsigned long) hp_sdc.base_io + 1;
1007         hp_sdc.status_io = (unsigned long) hp_sdc.base_io + 3;
1008         fs = get_fs();
1009         set_fs(KERNEL_DS);
1010         if (!get_user(i, (unsigned char *)hp_sdc.data_io))
1011                 hp_sdc.dev = (void *)1;
1012         set_fs(fs);
1013         hp_sdc.dev_err   = hp_sdc_init();
1014 #endif
1015         if (hp_sdc.dev == NULL) {
1016                 printk(KERN_WARNING PREFIX "No SDC found.\n");
1017                 return hp_sdc.dev_err;
1018         }
1019
1020         init_MUTEX_LOCKED(&tq_init_sem);
1021
1022         tq_init.actidx          = 0;
1023         tq_init.idx             = 1;
1024         tq_init.endidx          = 5;
1025         tq_init.seq             = tq_init_seq;
1026         tq_init.act.semaphore   = &tq_init_sem;
1027
1028         tq_init_seq[0] =
1029                 HP_SDC_ACT_POSTCMD | HP_SDC_ACT_DATAIN | HP_SDC_ACT_SEMAPHORE;
1030         tq_init_seq[1] = HP_SDC_CMD_READ_KCC;
1031         tq_init_seq[2] = 1;
1032         tq_init_seq[3] = 0;
1033         tq_init_seq[4] = 0;
1034
1035         hp_sdc_enqueue_transaction(&tq_init);
1036
1037         down(&tq_init_sem);
1038         up(&tq_init_sem);
1039
1040         if ((tq_init_seq[0] & HP_SDC_ACT_DEAD) == HP_SDC_ACT_DEAD) {
1041                 printk(KERN_WARNING PREFIX "Error reading config byte.\n");
1042                 hp_sdc_exit();
1043                 return -ENODEV;
1044         }
1045         hp_sdc.r11 = tq_init_seq[4];
1046         if (hp_sdc.r11 & HP_SDC_CFG_NEW) {
1047                 const char *str;
1048                 printk(KERN_INFO PREFIX "New style SDC\n");
1049                 tq_init_seq[1] = HP_SDC_CMD_READ_XTD;
1050                 tq_init.actidx          = 0;
1051                 tq_init.idx             = 1;
1052                 down(&tq_init_sem);
1053                 hp_sdc_enqueue_transaction(&tq_init);
1054                 down(&tq_init_sem);
1055                 up(&tq_init_sem);
1056                 if ((tq_init_seq[0] & HP_SDC_ACT_DEAD) == HP_SDC_ACT_DEAD) {
1057                         printk(KERN_WARNING PREFIX "Error reading extended config byte.\n");
1058                         return -ENODEV;
1059                 }
1060                 hp_sdc.r7e = tq_init_seq[4];
1061                 HP_SDC_XTD_REV_STRINGS(hp_sdc.r7e & HP_SDC_XTD_REV, str)
1062                 printk(KERN_INFO PREFIX "Revision: %s\n", str);
1063                 if (hp_sdc.r7e & HP_SDC_XTD_BEEPER)
1064                         printk(KERN_INFO PREFIX "TI SN76494 beeper present\n");
1065                 if (hp_sdc.r7e & HP_SDC_XTD_BBRTC)
1066                         printk(KERN_INFO PREFIX "OKI MSM-58321 BBRTC present\n");
1067                 printk(KERN_INFO PREFIX "Spunking the self test register to force PUP "
1068                        "on next firmware reset.\n");
1069                 tq_init_seq[0] = HP_SDC_ACT_PRECMD |
1070                         HP_SDC_ACT_DATAOUT | HP_SDC_ACT_SEMAPHORE;
1071                 tq_init_seq[1] = HP_SDC_CMD_SET_STR;
1072                 tq_init_seq[2] = 1;
1073                 tq_init_seq[3] = 0;
1074                 tq_init.actidx          = 0;
1075                 tq_init.idx             = 1;
1076                 tq_init.endidx          = 4;
1077                 down(&tq_init_sem);
1078                 hp_sdc_enqueue_transaction(&tq_init);
1079                 down(&tq_init_sem);
1080                 up(&tq_init_sem);
1081         } else
1082                 printk(KERN_INFO PREFIX "Old style SDC (1820-%s).\n",
1083                        (hp_sdc.r11 & HP_SDC_CFG_REV) ? "3300" : "2564/3087");
1084
1085         return 0;
1086 }
1087
1088 module_init(hp_sdc_register);
1089 module_exit(hp_sdc_exit);
1090
1091 /* Timing notes:  These measurements taken on my 64MHz 7100-LC (715/64)
1092  *                                              cycles cycles-adj    time
1093  * between two consecutive mfctl(16)'s:              4        n/a    63ns
1094  * hp_sdc_spin_ibf when idle:                      119        115   1.7us
1095  * gsc_writeb status register:                      83         79   1.2us
1096  * IBF to clear after sending SET_IM:             6204       6006    93us
1097  * IBF to clear after sending LOAD_RT:            4467       4352    68us
1098  * IBF to clear after sending two LOAD_RTs:      18974      18859   295us
1099  * READ_T1, read status/data, IRQ, call handler: 35564        n/a   556us
1100  * cmd to ~IBF READ_T1 2nd time right after:   5158403        n/a    81ms
1101  * between IRQ received and ~IBF for above:    2578877        n/a    40ms
1102  *
1103  * Performance stats after a run of this module configuring HIL and
1104  * receiving a few mouse events:
1105  *
1106  * status in8  282508 cycles 7128 calls
1107  * status out8   8404 cycles  341 calls
1108  * data out8     1734 cycles   78 calls
1109  * isr         174324 cycles  617 calls (includes take)
1110  * take          1241 cycles    2 calls
1111  * put        1411504 cycles 6937 calls
1112  * task       1655209 cycles 6937 calls (includes put)
1113  *
1114  */