1 /*
2 * Copyright 2003-2006 Simtec Electronics
3 * Ben Dooks <ben@simtec.co.uk>
4 *
5 * S3C2410 DMA core
6 *
7 * http://armlinux.simtec.co.uk/
8 *
9 * This program is free software; you can redistribute it and/or modify
10 * it under the terms of the GNU General Public License version 2 as
11 * published by the Free Software Foundation.
12 */
13
14
15 #ifdef CONFIG_S3C2410_DMA_DEBUG
16 #define DEBUG
17 #endif
18
19 #include <linux/module.h>
20 #include <linux/init.h>
21 #include <linux/sched.h>
22 #include <linux/spinlock.h>
23 #include <linux/interrupt.h>
24 #include <linux/syscore_ops.h>
25 #include <linux/slab.h>
26 #include <linux/errno.h>
27 #include <linux/io.h>
28
29 #include <asm/irq.h>
30 #include <mach/hardware.h>
31 #include <mach/dma.h>
32 #include <mach/map.h>
33
34 #include <plat/dma-s3c24xx.h>
35 #include <plat/regs-dma.h>
36
37 /* io map for dma */
38 static void __iomem *dma_base;
39 static struct kmem_cache *dma_kmem;
40
41 static int dma_channels;
42
43 static struct s3c24xx_dma_selection dma_sel;
44
45
46 /* debugging functions */
47
48 #define BUF_MAGIC (0xcafebabe)
49
50 #define dmawarn(fmt...) printk(KERN_DEBUG fmt)
51
52 #define dma_regaddr(chan, reg) ((chan)->regs + (reg))
53
54 #if 1
55 #define dma_wrreg(chan, reg, val) writel((val), (chan)->regs + (reg))
56 #else
57 static inline void
58 dma_wrreg(struct s3c2410_dma_chan *chan, int reg, unsigned long val)
59 {
60 pr_debug("writing %08x to register %08x\n",(unsigned int)val,reg);
61 writel(val, dma_regaddr(chan, reg));
62 }
63 #endif
64
65 #define dma_rdreg(chan, reg) readl((chan)->regs + (reg))
66
67 /* captured register state for debug */
68
69 struct s3c2410_dma_regstate {
70 unsigned long dcsrc;
71 unsigned long disrc;
72 unsigned long dstat;
73 unsigned long dcon;
74 unsigned long dmsktrig;
75 };
76
77 #ifdef CONFIG_S3C2410_DMA_DEBUG
78
79 /* dmadbg_showregs
80 *
81 * simple debug routine to print the current state of the dma registers
82 */
83
84 static void
85 dmadbg_capture(struct s3c2410_dma_chan *chan, struct s3c2410_dma_regstate *regs)
86 {
87 regs->dcsrc = dma_rdreg(chan, S3C2410_DMA_DCSRC);
88 regs->disrc = dma_rdreg(chan, S3C2410_DMA_DISRC);
89 regs->dstat = dma_rdreg(chan, S3C2410_DMA_DSTAT);
90 regs->dcon = dma_rdreg(chan, S3C2410_DMA_DCON);
91 regs->dmsktrig = dma_rdreg(chan, S3C2410_DMA_DMASKTRIG);
92 }
93
94 static void
95 dmadbg_dumpregs(const char *fname, int line, struct s3c2410_dma_chan *chan,
96 struct s3c2410_dma_regstate *regs)
97 {
98 printk(KERN_DEBUG "dma%d: %s:%d: DCSRC=%08lx, DISRC=%08lx, DSTAT=%08lx DMT=%02lx, DCON=%08lx\n",
99 chan->number, fname, line,
100 regs->dcsrc, regs->disrc, regs->dstat, regs->dmsktrig,
101 regs->dcon);
102 }
103
104 static void
105 dmadbg_showchan(const char *fname, int line, struct s3c2410_dma_chan *chan)
106 {
107 struct s3c2410_dma_regstate state;
108
109 dmadbg_capture(chan, &state);
110
111 printk(KERN_DEBUG "dma%d: %s:%d: ls=%d, cur=%p, %p %p\n",
112 chan->number, fname, line, chan->load_state,
113 chan->curr, chan->next, chan->end);
114
115 dmadbg_dumpregs(fname, line, chan, &state);
116 }
117
118 static void
119 dmadbg_showregs(const char *fname, int line, struct s3c2410_dma_chan *chan)
120 {
121 struct s3c2410_dma_regstate state;
122
123 dmadbg_capture(chan, &state);
124 dmadbg_dumpregs(fname, line, chan, &state);
125 }
126
127 #define dbg_showregs(chan) dmadbg_showregs(__func__, __LINE__, (chan))
128 #define dbg_showchan(chan) dmadbg_showchan(__func__, __LINE__, (chan))
129 #else
130 #define dbg_showregs(chan) do { } while(0)
131 #define dbg_showchan(chan) do { } while(0)
132 #endif /* CONFIG_S3C2410_DMA_DEBUG */
133
134 /* s3c2410_dma_stats_timeout
135 *
136 * Update DMA stats from timeout info
137 */
138
139 static void
140 s3c2410_dma_stats_timeout(struct s3c2410_dma_stats *stats, int val)
141 {
142 if (stats == NULL)
143 return;
144
145 if (val > stats->timeout_longest)
146 stats->timeout_longest = val;
147 if (val < stats->timeout_shortest)
148 stats->timeout_shortest = val;
149
150 stats->timeout_avg += val;
151 }
152
153 /* s3c2410_dma_waitforload
154 *
155 * wait for the DMA engine to load a buffer, and update the state accordingly
156 */
157
158 static int
159 s3c2410_dma_waitforload(struct s3c2410_dma_chan *chan, int line)
160 {
161 int timeout = chan->load_timeout;
162 int took;
163
164 if (chan->load_state != S3C2410_DMALOAD_1LOADED) {
165 printk(KERN_ERR "dma%d: s3c2410_dma_waitforload() called in loadstate %d from line %d\n", chan->number, chan->load_state, line);
166 return 0;
167 }
168
169 if (chan->stats != NULL)
170 chan->stats->loads++;
171
172 while (--timeout > 0) {
173 if ((dma_rdreg(chan, S3C2410_DMA_DSTAT) << (32-20)) != 0) {
174 took = chan->load_timeout - timeout;
175
176 s3c2410_dma_stats_timeout(chan->stats, took);
177
178 switch (chan->load_state) {
179 case S3C2410_DMALOAD_1LOADED:
180 chan->load_state = S3C2410_DMALOAD_1RUNNING;
181 break;
182
183 default:
184 printk(KERN_ERR "dma%d: unknown load_state in s3c2410_dma_waitforload() %d\n", chan->number, chan->load_state);
185 }
186
187 return 1;
188 }
189 }
190
191 if (chan->stats != NULL) {
192 chan->stats->timeout_failed++;
193 }
194
195 return 0;
196 }
197
198 /* s3c2410_dma_loadbuffer
199 *
200 * load a buffer, and update the channel state
201 */
202
203 static inline int
204 s3c2410_dma_loadbuffer(struct s3c2410_dma_chan *chan,
205 struct s3c2410_dma_buf *buf)
206 {
207 unsigned long reload;
208
209 if (buf == NULL) {
210 dmawarn("buffer is NULL\n");
211 return -EINVAL;
212 }
213
214 pr_debug("s3c2410_chan_loadbuffer: loading buff %p (0x%08lx,0x%06x)\n",
215 buf, (unsigned long)buf->data, buf->size);
216
217 /* check the state of the channel before we do anything */
218
219 if (chan->load_state == S3C2410_DMALOAD_1LOADED) {
220 dmawarn("load_state is S3C2410_DMALOAD_1LOADED\n");
221 }
222
223 if (chan->load_state == S3C2410_DMALOAD_1LOADED_1RUNNING) {
224 dmawarn("state is S3C2410_DMALOAD_1LOADED_1RUNNING\n");
225 }
226
227 /* it would seem sensible if we are the last buffer to not bother
228 * with the auto-reload bit, so that the DMA engine will not try
229 * and load another transfer after this one has finished...
230 */
231 if (chan->load_state == S3C2410_DMALOAD_NONE) {
232 pr_debug("load_state is none, checking for noreload (next=%p)\n",
233 buf->next);
234 reload = (buf->next == NULL) ? S3C2410_DCON_NORELOAD : 0;
235 } else {
236 //pr_debug("load_state is %d => autoreload\n", chan->load_state);
237 reload = S3C2410_DCON_AUTORELOAD;
238 }
239
240 if ((buf->data & 0xf0000000) != 0x30000000) {
241 dmawarn("dmaload: buffer is %p\n", (void *)buf->data);
242 }
243
244 writel(buf->data, chan->addr_reg);
245
246 dma_wrreg(chan, S3C2410_DMA_DCON,
247 chan->dcon | reload | (buf->size/chan->xfer_unit));
248
249 chan->next = buf->next;
250
251 /* update the state of the channel */
252
253 switch (chan->load_state) {
254 case S3C2410_DMALOAD_NONE:
255 chan->load_state = S3C2410_DMALOAD_1LOADED;
256 break;
257
258 case S3C2410_DMALOAD_1RUNNING:
259 chan->load_state = S3C2410_DMALOAD_1LOADED_1RUNNING;
260 break;
261
262 default:
263 dmawarn("dmaload: unknown state %d in loadbuffer\n",
264 chan->load_state);
265 break;
266 }
267
268 return 0;
269 }
270
271 /* s3c2410_dma_call_op
272 *
273 * small routine to call the op routine with the given op if it has been
274 * registered
275 */
276
277 static void
278 s3c2410_dma_call_op(struct s3c2410_dma_chan *chan, enum s3c2410_chan_op op)
279 {
280 if (chan->op_fn != NULL) {
281 (chan->op_fn)(chan, op);
282 }
283 }
284
285 /* s3c2410_dma_buffdone
286 *
287 * small wrapper to check if callback routine needs to be called, and
288 * if so, call it
289 */
290
291 static inline void
292 s3c2410_dma_buffdone(struct s3c2410_dma_chan *chan, struct s3c2410_dma_buf *buf,
293 enum s3c2410_dma_buffresult result)
294 {
295 #if 0
296 pr_debug("callback_fn=%p, buf=%p, id=%p, size=%d, result=%d\n",
297 chan->callback_fn, buf, buf->id, buf->size, result);
298 #endif
299
300 if (chan->callback_fn != NULL) {
301 (chan->callback_fn)(chan, buf->id, buf->size, result);
302 }
303 }
304
305 /* s3c2410_dma_start
306 *
307 * start a dma channel going
308 */
309
310 static int s3c2410_dma_start(struct s3c2410_dma_chan *chan)
311 {
312 unsigned long tmp;
313 unsigned long flags;
314
315 pr_debug("s3c2410_start_dma: channel=%d\n", chan->number);
316
317 local_irq_save(flags);
318
319 if (chan->state == S3C2410_DMA_RUNNING) {
320 pr_debug("s3c2410_start_dma: already running (%d)\n", chan->state);
321 local_irq_restore(flags);
322 return 0;
323 }
324
325 chan->state = S3C2410_DMA_RUNNING;
326
327 /* check whether there is anything to load, and if not, see
328 * if we can find anything to load
329 */
330
331 if (chan->load_state == S3C2410_DMALOAD_NONE) {
332 if (chan->next == NULL) {
333 printk(KERN_ERR "dma%d: channel has nothing loaded\n",
334 chan->number);
335 chan->state = S3C2410_DMA_IDLE;
336 local_irq_restore(flags);
337 return -EINVAL;
338 }
339
340 s3c2410_dma_loadbuffer(chan, chan->next);
341 }
342
343 dbg_showchan(chan);
344
345 /* enable the channel */
346
347 if (!chan->irq_enabled) {
348 enable_irq(chan->irq);
349 chan->irq_enabled = 1;
350 }
351
352 /* start the channel going */
353
354 tmp = dma_rdreg(chan, S3C2410_DMA_DMASKTRIG);
355 tmp &= ~S3C2410_DMASKTRIG_STOP;
356 tmp |= S3C2410_DMASKTRIG_ON;
357 dma_wrreg(chan, S3C2410_DMA_DMASKTRIG, tmp);
358
359 pr_debug("dma%d: %08lx to DMASKTRIG\n", chan->number, tmp);
360
361 #if 0
362 /* the dma buffer loads should take care of clearing the AUTO
363 * reloading feature */
364 tmp = dma_rdreg(chan, S3C2410_DMA_DCON);
365 tmp &= ~S3C2410_DCON_NORELOAD;
366 dma_wrreg(chan, S3C2410_DMA_DCON, tmp);
367 #endif
368
369 s3c2410_dma_call_op(chan, S3C2410_DMAOP_START);
370
371 dbg_showchan(chan);
372
373 /* if we've only loaded one buffer onto the channel, then chec
374 * to see if we have another, and if so, try and load it so when
375 * the first buffer is finished, the new one will be loaded onto
376 * the channel */
377
378 if (chan->next != NULL) {
379 if (chan->load_state == S3C2410_DMALOAD_1LOADED) {
380
381 if (s3c2410_dma_waitforload(chan, __LINE__) == 0) {
382 pr_debug("%s: buff not yet loaded, no more todo\n",
383 __func__);
384 } else {
385 chan->load_state = S3C2410_DMALOAD_1RUNNING;
386 s3c2410_dma_loadbuffer(chan, chan->next);
387 }
388
389 } else if (chan->load_state == S3C2410_DMALOAD_1RUNNING) {
390 s3c2410_dma_loadbuffer(chan, chan->next);
391 }
392 }
393
394
395 local_irq_restore(flags);
396
397 return 0;
398 }
399
400 /* s3c2410_dma_canload
401 *
402 * work out if we can queue another buffer into the DMA engine
403 */
404
405 static int
406 s3c2410_dma_canload(struct s3c2410_dma_chan *chan)
407 {
408 if (chan->load_state == S3C2410_DMALOAD_NONE ||
409 chan->load_state == S3C2410_DMALOAD_1RUNNING)
410 return 1;
411
412 return 0;
413 }
414
415 /* s3c2410_dma_enqueue
416 *
417 * queue an given buffer for dma transfer.
418 *
419 * id the device driver's id information for this buffer
420 * data the physical address of the buffer data
421 * size the size of the buffer in bytes
422 *
423 * If the channel is not running, then the flag S3C2410_DMAF_AUTOSTART
424 * is checked, and if set, the channel is started. If this flag isn't set,
425 * then an error will be returned.
426 *
427 * It is possible to queue more than one DMA buffer onto a channel at
428 * once, and the code will deal with the re-loading of the next buffer
429 * when necessary.
430 */
431
432 int s3c2410_dma_enqueue(enum dma_ch channel, void *id,
433 dma_addr_t data, int size)
434 {
435 struct s3c2410_dma_chan *chan = s3c_dma_lookup_channel(channel);
436 struct s3c2410_dma_buf *buf;
437 unsigned long flags;
438
439 if (chan == NULL)
440 return -EINVAL;
441
442 pr_debug("%s: id=%p, data=%08x, size=%d\n",
443 __func__, id, (unsigned int)data, size);
444
445 buf = kmem_cache_alloc(dma_kmem, GFP_ATOMIC);
446 if (buf == NULL) {
447 pr_debug("%s: out of memory (%ld alloc)\n",
448 __func__, (long)sizeof(*buf));
449 return -ENOMEM;
450 }
451
452 //pr_debug("%s: new buffer %p\n", __func__, buf);
453 //dbg_showchan(chan);
454
455 buf->next = NULL;
456 buf->data = buf->ptr = data;
457 buf->size = size;
458 buf->id = id;
459 buf->magic = BUF_MAGIC;
460
461 local_irq_save(flags);
462
463 if (chan->curr == NULL) {
464 /* we've got nothing loaded... */
465 pr_debug("%s: buffer %p queued onto empty channel\n",
466 __func__, buf);
467
468 chan->curr = buf;
469 chan->end = buf;
470 chan->next = NULL;
471 } else {
472 pr_debug("dma%d: %s: buffer %p queued onto non-empty channel\n",
473 chan->number, __func__, buf);
474
475 if (chan->end == NULL) {
476 pr_debug("dma%d: %s: %p not empty, and chan->end==NULL?\n",
477 chan->number, __func__, chan);
478 } else {
479 chan->end->next = buf;
480 chan->end = buf;
481 }
482 }
483
484 /* if necessary, update the next buffer field */
485 if (chan->next == NULL)
486 chan->next = buf;
487
488 /* check to see if we can load a buffer */
489 if (chan->state == S3C2410_DMA_RUNNING) {
490 if (chan->load_state == S3C2410_DMALOAD_1LOADED && 1) {
491 if (s3c2410_dma_waitforload(chan, __LINE__) == 0) {
492 printk(KERN_ERR "dma%d: loadbuffer:"
493 "timeout loading buffer\n",
494 chan->number);
495 dbg_showchan(chan);
496 local_irq_restore(flags);
497 return -EINVAL;
498 }
499 }
500
501 while (s3c2410_dma_canload(chan) && chan->next != NULL) {
502 s3c2410_dma_loadbuffer(chan, chan->next);
503 }
504 } else if (chan->state == S3C2410_DMA_IDLE) {
505 if (chan->flags & S3C2410_DMAF_AUTOSTART) {
506 s3c2410_dma_ctrl(chan->number | DMACH_LOW_LEVEL,
507 S3C2410_DMAOP_START);
508 }
509 }
510
511 local_irq_restore(flags);
512 return 0;
513 }
514
515 EXPORT_SYMBOL(s3c2410_dma_enqueue);
516
517 static inline void
518 s3c2410_dma_freebuf(struct s3c2410_dma_buf *buf)
519 {
520 int magicok = (buf->magic == BUF_MAGIC);
521
522 buf->magic = -1;
523
524 if (magicok) {
525 kmem_cache_free(dma_kmem, buf);
526 } else {
527 printk("s3c2410_dma_freebuf: buff %p with bad magic\n", buf);
528 }
529 }
530
531 /* s3c2410_dma_lastxfer
532 *
533 * called when the system is out of buffers, to ensure that the channel
534 * is prepared for shutdown.
535 */
536
537 static inline void
538 s3c2410_dma_lastxfer(struct s3c2410_dma_chan *chan)
539 {
540 #if 0
541 pr_debug("dma%d: s3c2410_dma_lastxfer: load_state %d\n",
542 chan->number, chan->load_state);
543 #endif
544
545 switch (chan->load_state) {
546 case S3C2410_DMALOAD_NONE:
547 break;
548
549 case S3C2410_DMALOAD_1LOADED:
550 if (s3c2410_dma_waitforload(chan, __LINE__) == 0) {
551 /* flag error? */
552 printk(KERN_ERR "dma%d: timeout waiting for load (%s)\n",
553 chan->number, __func__);
554 return;
555 }
556 break;
557
558 case S3C2410_DMALOAD_1LOADED_1RUNNING:
559 /* I believe in this case we do not have anything to do
560 * until the next buffer comes along, and we turn off the
561 * reload */
562 return;
563
564 default:
565 pr_debug("dma%d: lastxfer: unhandled load_state %d with no next\n",
566 chan->number, chan->load_state);
567 return;
568
569 }
570
571 /* hopefully this'll shut the damned thing up after the transfer... */
572 dma_wrreg(chan, S3C2410_DMA_DCON, chan->dcon | S3C2410_DCON_NORELOAD);
573 }
574
575
576 #define dmadbg2(x...)
577
578 static irqreturn_t
579 s3c2410_dma_irq(int irq, void *devpw)
580 {
581 struct s3c2410_dma_chan *chan = (struct s3c2410_dma_chan *)devpw;
582 struct s3c2410_dma_buf *buf;
583
584 buf = chan->curr;
585
586 dbg_showchan(chan);
587
588 /* modify the channel state */
589
590 switch (chan->load_state) {
591 case S3C2410_DMALOAD_1RUNNING:
592 /* TODO - if we are running only one buffer, we probably
593 * want to reload here, and then worry about the buffer
594 * callback */
595
596 chan->load_state = S3C2410_DMALOAD_NONE;
597 break;
598
599 case S3C2410_DMALOAD_1LOADED:
600 /* iirc, we should go back to NONE loaded here, we
601 * had a buffer, and it was never verified as being
602 * loaded.
603 */
604
605 chan->load_state = S3C2410_DMALOAD_NONE;
606 break;
607
608 case S3C2410_DMALOAD_1LOADED_1RUNNING:
609 /* we'll worry about checking to see if another buffer is
610 * ready after we've called back the owner. This should
611 * ensure we do not wait around too long for the DMA
612 * engine to start the next transfer
613 */
614
615 chan->load_state = S3C2410_DMALOAD_1LOADED;
616 break;
617
618 case S3C2410_DMALOAD_NONE:
619 printk(KERN_ERR "dma%d: IRQ with no loaded buffer?\n",
620 chan->number);
621 break;
622
623 default:
624 printk(KERN_ERR "dma%d: IRQ in invalid load_state %d\n",
625 chan->number, chan->load_state);
626 break;
627 }
628
629 if (buf != NULL) {
630 /* update the chain to make sure that if we load any more
631 * buffers when we call the callback function, things should
632 * work properly */
633
634 chan->curr = buf->next;
635 buf->next = NULL;
636
637 if (buf->magic != BUF_MAGIC) {
638 printk(KERN_ERR "dma%d: %s: buf %p incorrect magic\n",
639 chan->number, __func__, buf);
640 return IRQ_HANDLED;
641 }
642
643 s3c2410_dma_buffdone(chan, buf, S3C2410_RES_OK);
644
645 /* free resouces */
646 s3c2410_dma_freebuf(buf);
647 } else {
648 }
649
650 /* only reload if the channel is still running... our buffer done
651 * routine may have altered the state by requesting the dma channel
652 * to stop or shutdown... */
653
654 /* todo: check that when the channel is shut-down from inside this
655 * function, we cope with unsetting reload, etc */
656
657 if (chan->next != NULL && chan->state != S3C2410_DMA_IDLE) {
658 unsigned long flags;
659
660 switch (chan->load_state) {
661 case S3C2410_DMALOAD_1RUNNING:
662 /* don't need to do anything for this state */
663 break;
664
665 case S3C2410_DMALOAD_NONE:
666 /* can load buffer immediately */
667 break;
668
669 case S3C2410_DMALOAD_1LOADED:
670 if (s3c2410_dma_waitforload(chan, __LINE__) == 0) {
671 /* flag error? */
672 printk(KERN_ERR "dma%d: timeout waiting for load (%s)\n",
673 chan->number, __func__);
674 return IRQ_HANDLED;
675 }
676
677 break;
678
679 case S3C2410_DMALOAD_1LOADED_1RUNNING:
680 goto no_load;
681
682 default:
683 printk(KERN_ERR "dma%d: unknown load_state in irq, %d\n",
684 chan->number, chan->load_state);
685 return IRQ_HANDLED;
686 }
687
688 local_irq_save(flags);
689 s3c2410_dma_loadbuffer(chan, chan->next);
690 local_irq_restore(flags);
691 } else {
692 s3c2410_dma_lastxfer(chan);
693
694 /* see if we can stop this channel.. */
695 if (chan->load_state == S3C2410_DMALOAD_NONE) {
696 pr_debug("dma%d: end of transfer, stopping channel (%ld)\n",
697 chan->number, jiffies);
698 s3c2410_dma_ctrl(chan->number | DMACH_LOW_LEVEL,
699 S3C2410_DMAOP_STOP);
700 }
701 }
702
703 no_load:
704 return IRQ_HANDLED;
705 }
706
707 static struct s3c2410_dma_chan *s3c2410_dma_map_channel(int channel);
708
709 /* s3c2410_request_dma
710 *
711 * get control of an dma channel
712 */
713
714 int s3c2410_dma_request(enum dma_ch channel,
715 struct s3c2410_dma_client *client,
716 void *dev)
717 {
718 struct s3c2410_dma_chan *chan;
719 unsigned long flags;
720 int err;
721
722 pr_debug("dma%d: s3c2410_request_dma: client=%s, dev=%p\n",
723 channel, client->name, dev);
724
725 local_irq_save(flags);
726
727 chan = s3c2410_dma_map_channel(channel);
728 if (chan == NULL) {
729 local_irq_restore(flags);
730 return -EBUSY;
731 }
732
733 dbg_showchan(chan);
734
735 chan->client = client;
736 chan->in_use = 1;
737
738 if (!chan->irq_claimed) {
739 pr_debug("dma%d: %s : requesting irq %d\n",
740 channel, __func__, chan->irq);
741
742 chan->irq_claimed = 1;
743 local_irq_restore(flags);
744
745 err = request_irq(chan->irq, s3c2410_dma_irq, IRQF_DISABLED,
746 client->name, (void *)chan);
747
748 local_irq_save(flags);
749
750 if (err) {
751 chan->in_use = 0;
752 chan->irq_claimed = 0;
753 local_irq_restore(flags);
754
755 printk(KERN_ERR "%s: cannot get IRQ %d for DMA %d\n",
756 client->name, chan->irq, chan->number);
757 return err;
758 }
759
760 chan->irq_enabled = 1;
761 }
762
763 local_irq_restore(flags);
764
765 /* need to setup */
766
767 pr_debug("%s: channel initialised, %p\n", __func__, chan);
768
769 return chan->number | DMACH_LOW_LEVEL;
770 }
771
772 EXPORT_SYMBOL(s3c2410_dma_request);
773
774 /* s3c2410_dma_free
775 *
776 * release the given channel back to the system, will stop and flush
777 * any outstanding transfers, and ensure the channel is ready for the
778 * next claimant.
779 *
780 * Note, although a warning is currently printed if the freeing client
781 * info is not the same as the registrant's client info, the free is still
782 * allowed to go through.
783 */
784
785 int s3c2410_dma_free(enum dma_ch channel, struct s3c2410_dma_client *client)
786 {
787 struct s3c2410_dma_chan *chan = s3c_dma_lookup_channel(channel);
788 unsigned long flags;
789
790 if (chan == NULL)
791 return -EINVAL;
792
793 local_irq_save(flags);
794
795 if (chan->client != client) {
796 printk(KERN_WARNING "dma%d: possible free from different client (channel %p, passed %p)\n",
797 channel, chan->client, client);
798 }
799
800 /* sort out stopping and freeing the channel */
801
802 if (chan->state != S3C2410_DMA_IDLE) {
803 pr_debug("%s: need to stop dma channel %p\n",
804 __func__, chan);
805
806 /* possibly flush the channel */
807 s3c2410_dma_ctrl(channel, S3C2410_DMAOP_STOP);
808 }
809
810 chan->client = NULL;
811 chan->in_use = 0;
812
813 if (chan->irq_claimed)
814 free_irq(chan->irq, (void *)chan);
815
816 chan->irq_claimed = 0;
817
818 if (!(channel & DMACH_LOW_LEVEL))
819 s3c_dma_chan_map[channel] = NULL;
820
821 local_irq_restore(flags);
822
823 return 0;
824 }
825
826 EXPORT_SYMBOL(s3c2410_dma_free);
827
828 static int s3c2410_dma_dostop(struct s3c2410_dma_chan *chan)
829 {
830 unsigned long flags;
831 unsigned long tmp;
832
833 pr_debug("%s:\n", __func__);
834
835 dbg_showchan(chan);
836
837 local_irq_save(flags);
838
839 s3c2410_dma_call_op(chan, S3C2410_DMAOP_STOP);
840
841 tmp = dma_rdreg(chan, S3C2410_DMA_DMASKTRIG);
842 tmp |= S3C2410_DMASKTRIG_STOP;
843 //tmp &= ~S3C2410_DMASKTRIG_ON;
844 dma_wrreg(chan, S3C2410_DMA_DMASKTRIG, tmp);
845
846 #if 0
847 /* should also clear interrupts, according to WinCE BSP */
848 tmp = dma_rdreg(chan, S3C2410_DMA_DCON);
849 tmp |= S3C2410_DCON_NORELOAD;
850 dma_wrreg(chan, S3C2410_DMA_DCON, tmp);
851 #endif
852
853 /* should stop do this, or should we wait for flush? */
854 chan->state = S3C2410_DMA_IDLE;
855 chan->load_state = S3C2410_DMALOAD_NONE;
856
857 local_irq_restore(flags);
858
859 return 0;
860 }
861
862 static void s3c2410_dma_waitforstop(struct s3c2410_dma_chan *chan)
863 {
864 unsigned long tmp;
865 unsigned int timeout = 0x10000;
866
867 while (timeout-- > 0) {
868 tmp = dma_rdreg(chan, S3C2410_DMA_DMASKTRIG);
869
870 if (!(tmp & S3C2410_DMASKTRIG_ON))
871 return;
872 }
873
874 pr_debug("dma%d: failed to stop?\n", chan->number);
875 }
876
877
878 /* s3c2410_dma_flush
879 *
880 * stop the channel, and remove all current and pending transfers
881 */
882
883 static int s3c2410_dma_flush(struct s3c2410_dma_chan *chan)
884 {
885 struct s3c2410_dma_buf *buf, *next;
886 unsigned long flags;
887
888 pr_debug("%s: chan %p (%d)\n", __func__, chan, chan->number);
889
890 dbg_showchan(chan);
891
892 local_irq_save(flags);
893
894 if (chan->state != S3C2410_DMA_IDLE) {
895 pr_debug("%s: stopping channel...\n", __func__ );
896 s3c2410_dma_ctrl(chan->number, S3C2410_DMAOP_STOP);
897 }
898
899 buf = chan->curr;
900 if (buf == NULL)
901 buf = chan->next;
902
903 chan->curr = chan->next = chan->end = NULL;
904
905 if (buf != NULL) {
906 for ( ; buf != NULL; buf = next) {
907 next = buf->next;
908
909 pr_debug("%s: free buffer %p, next %p\n",
910 __func__, buf, buf->next);
911
912 s3c2410_dma_buffdone(chan, buf, S3C2410_RES_ABORT);
913 s3c2410_dma_freebuf(buf);
914 }
915 }
916
917 dbg_showregs(chan);
918
919 s3c2410_dma_waitforstop(chan);
920
921 #if 0
922 /* should also clear interrupts, according to WinCE BSP */
923 {
924 unsigned long tmp;
925
926 tmp = dma_rdreg(chan, S3C2410_DMA_DCON);
927 tmp |= S3C2410_DCON_NORELOAD;
928 dma_wrreg(chan, S3C2410_DMA_DCON, tmp);
929 }
930 #endif
931
932 dbg_showregs(chan);
933
934 local_irq_restore(flags);
935
936 return 0;
937 }
938
939 static int s3c2410_dma_started(struct s3c2410_dma_chan *chan)
940 {
941 unsigned long flags;
942
943 local_irq_save(flags);
944
945 dbg_showchan(chan);
946
947 /* if we've only loaded one buffer onto the channel, then chec
948 * to see if we have another, and if so, try and load it so when
949 * the first buffer is finished, the new one will be loaded onto
950 * the channel */
951
952 if (chan->next != NULL) {
953 if (chan->load_state == S3C2410_DMALOAD_1LOADED) {
954
955 if (s3c2410_dma_waitforload(chan, __LINE__) == 0) {
956 pr_debug("%s: buff not yet loaded, no more todo\n",
957 __func__);
958 } else {
959 chan->load_state = S3C2410_DMALOAD_1RUNNING;
960 s3c2410_dma_loadbuffer(chan, chan->next);
961 }
962
963 } else if (chan->load_state == S3C2410_DMALOAD_1RUNNING) {
964 s3c2410_dma_loadbuffer(chan, chan->next);
965 }
966 }
967
968
969 local_irq_restore(flags);
970
971 return 0;
972
973 }
974
975 int
976 s3c2410_dma_ctrl(enum dma_ch channel, enum s3c2410_chan_op op)
977 {
978 struct s3c2410_dma_chan *chan = s3c_dma_lookup_channel(channel);
979
980 if (chan == NULL)
981 return -EINVAL;
982
983 switch (op) {
984 case S3C2410_DMAOP_START:
985 return s3c2410_dma_start(chan);
986
987 case S3C2410_DMAOP_STOP:
988 return s3c2410_dma_dostop(chan);
989
990 case S3C2410_DMAOP_PAUSE:
991 case S3C2410_DMAOP_RESUME:
992 return -ENOENT;
993
994 case S3C2410_DMAOP_FLUSH:
995 return s3c2410_dma_flush(chan);
996
997 case S3C2410_DMAOP_STARTED:
998 return s3c2410_dma_started(chan);
999
1000 case S3C2410_DMAOP_TIMEOUT:
1001 return 0;
1002
1003 }
1004
1005 return -ENOENT; /* unknown, don't bother */
1006 }
1007
1008 EXPORT_SYMBOL(s3c2410_dma_ctrl);
1009
1010 /* DMA configuration for each channel
1011 *
1012 * DISRCC -> source of the DMA (AHB,APB)
1013 * DISRC -> source address of the DMA
1014 * DIDSTC -> destination of the DMA (AHB,APD)
1015 * DIDST -> destination address of the DMA
1016 */
1017
1018 /* s3c2410_dma_config
1019 *
1020 * xfersize: size of unit in bytes (1,2,4)
1021 */
1022
1023 int s3c2410_dma_config(enum dma_ch channel,
1024 int xferunit)
1025 {
1026 struct s3c2410_dma_chan *chan = s3c_dma_lookup_channel(channel);
1027 unsigned int dcon;
1028
1029 pr_debug("%s: chan=%d, xfer_unit=%d\n", __func__, channel, xferunit);
1030
1031 if (chan == NULL)
1032 return -EINVAL;
1033
1034 dcon = chan->dcon & dma_sel.dcon_mask;
1035 pr_debug("%s: dcon is %08x\n", __func__, dcon);
1036
1037 switch (chan->req_ch) {
1038 case DMACH_I2S_IN:
1039 case DMACH_I2S_OUT:
1040 case DMACH_PCM_IN:
1041 case DMACH_PCM_OUT:
1042 case DMACH_MIC_IN:
1043 default:
1044 dcon |= S3C2410_DCON_HANDSHAKE;
1045 dcon |= S3C2410_DCON_SYNC_PCLK;
1046 break;
1047
1048 case DMACH_SDI:
1049 /* note, ensure if need HANDSHAKE or not */
1050 dcon |= S3C2410_DCON_SYNC_PCLK;
1051 break;
1052
1053 case DMACH_XD0:
1054 case DMACH_XD1:
1055 dcon |= S3C2410_DCON_HANDSHAKE;
1056 dcon |= S3C2410_DCON_SYNC_HCLK;
1057 break;
1058 }
1059
1060 switch (xferunit) {
1061 case 1:
1062 dcon |= S3C2410_DCON_BYTE;
1063 break;
1064
1065 case 2:
1066 dcon |= S3C2410_DCON_HALFWORD;
1067 break;
1068
1069 case 4:
1070 dcon |= S3C2410_DCON_WORD;
1071 break;
1072
1073 default:
1074 pr_debug("%s: bad transfer size %d\n", __func__, xferunit);
1075 return -EINVAL;
1076 }
1077
1078 dcon |= S3C2410_DCON_HWTRIG;
1079 dcon |= S3C2410_DCON_INTREQ;
1080
1081 pr_debug("%s: dcon now %08x\n", __func__, dcon);
1082
1083 chan->dcon = dcon;
1084 chan->xfer_unit = xferunit;
1085
1086 return 0;
1087 }
1088
1089 EXPORT_SYMBOL(s3c2410_dma_config);
1090
1091
1092 /* s3c2410_dma_devconfig
1093 *
1094 * configure the dma source/destination hardware type and address
1095 *
1096 * source: DMA_FROM_DEVICE: source is hardware
1097 * DMA_TO_DEVICE: source is memory
1098 *
1099 * devaddr: physical address of the source
1100 */
1101
1102 int s3c2410_dma_devconfig(enum dma_ch channel,
1103 enum dma_data_direction source,
1104 unsigned long devaddr)
1105 {
1106 struct s3c2410_dma_chan *chan = s3c_dma_lookup_channel(channel);
1107 unsigned int hwcfg;
1108
1109 if (chan == NULL)
1110 return -EINVAL;
1111
1112 pr_debug("%s: source=%d, devaddr=%08lx\n",
1113 __func__, (int)source, devaddr);
1114
1115 chan->source = source;
1116 chan->dev_addr = devaddr;
1117
1118 switch (chan->req_ch) {
1119 case DMACH_XD0:
1120 case DMACH_XD1:
1121 hwcfg = 0; /* AHB */
1122 break;
1123
1124 default:
1125 hwcfg = S3C2410_DISRCC_APB;
1126 }
1127
1128 /* always assume our peripheral desintation is a fixed
1129 * address in memory. */
1130 hwcfg |= S3C2410_DISRCC_INC;
1131
1132 switch (source) {
1133 case DMA_FROM_DEVICE:
1134 /* source is hardware */
1135 pr_debug("%s: hw source, devaddr=%08lx, hwcfg=%d\n",
1136 __func__, devaddr, hwcfg);
1137 dma_wrreg(chan, S3C2410_DMA_DISRCC, hwcfg & 3);
1138 dma_wrreg(chan, S3C2410_DMA_DISRC, devaddr);
1139 dma_wrreg(chan, S3C2410_DMA_DIDSTC, (0<<1) | (0<<0));
1140
1141 chan->addr_reg = dma_regaddr(chan, S3C2410_DMA_DIDST);
1142 break;
1143
1144 case DMA_TO_DEVICE:
1145 /* source is memory */
1146 pr_debug("%s: mem source, devaddr=%08lx, hwcfg=%d\n",
1147 __func__, devaddr, hwcfg);
1148 dma_wrreg(chan, S3C2410_DMA_DISRCC, (0<<1) | (0<<0));
1149 dma_wrreg(chan, S3C2410_DMA_DIDST, devaddr);
1150 dma_wrreg(chan, S3C2410_DMA_DIDSTC, hwcfg & 3);
1151
1152 chan->addr_reg = dma_regaddr(chan, S3C2410_DMA_DISRC);
1153 break;
1154
1155 default:
1156 printk(KERN_ERR "dma%d: invalid source type (%d)\n",
1157 channel, source);
1158
1159 return -EINVAL;
1160 }
1161
1162 return 0;
1163 }
1164
1165 EXPORT_SYMBOL(s3c2410_dma_devconfig);
1166
1167 /* s3c2410_dma_getposition
1168 *
1169 * returns the current transfer points for the dma source and destination
1170 */
1171
1172 int s3c2410_dma_getposition(enum dma_ch channel, dma_addr_t *src, dma_addr_t *dst)
1173 {
1174 struct s3c2410_dma_chan *chan = s3c_dma_lookup_channel(channel);
1175
1176 if (chan == NULL)
1177 return -EINVAL;
1178
1179 if (src != NULL)
1180 *src = dma_rdreg(chan, S3C2410_DMA_DCSRC);
1181
1182 if (dst != NULL)
1183 *dst = dma_rdreg(chan, S3C2410_DMA_DCDST);
1184
1185 return 0;
1186 }
1187
1188 EXPORT_SYMBOL(s3c2410_dma_getposition);
1189
1190 /* system core operations */
1191
1192 #ifdef CONFIG_PM
1193
1194 static void s3c2410_dma_suspend_chan(struct s3c2410_dma_chan *cp)
1195 {
1196 printk(KERN_DEBUG "suspending dma channel %d\n", cp->number);
1197
1198 if (dma_rdreg(cp, S3C2410_DMA_DMASKTRIG) & S3C2410_DMASKTRIG_ON) {
1199 /* the dma channel is still working, which is probably
1200 * a bad thing to do over suspend/resume. We stop the
1201 * channel and assume that the client is either going to
1202 * retry after resume, or that it is broken.
1203 */
1204
1205 printk(KERN_INFO "dma: stopping channel %d due to suspend\n",
1206 cp->number);
1207
1208 s3c2410_dma_dostop(cp);
1209 }
1210 }
1211
1212 static int s3c2410_dma_suspend(void)
1213 {
1214 struct s3c2410_dma_chan *cp = s3c2410_chans;
1215 int channel;
1216
1217 for (channel = 0; channel < dma_channels; cp++, channel++)
1218 s3c2410_dma_suspend_chan(cp);
1219
1220 return 0;
1221 }
1222
1223 static void s3c2410_dma_resume_chan(struct s3c2410_dma_chan *cp)
1224 {
1225 unsigned int no = cp->number | DMACH_LOW_LEVEL;
1226
1227 /* restore channel's hardware configuration */
1228
1229 if (!cp->in_use)
1230 return;
1231
1232 printk(KERN_INFO "dma%d: restoring configuration\n", cp->number);
1233
1234 s3c2410_dma_config(no, cp->xfer_unit);
1235 s3c2410_dma_devconfig(no, cp->source, cp->dev_addr);
1236
1237 /* re-select the dma source for this channel */
1238
1239 if (cp->map != NULL)
1240 dma_sel.select(cp, cp->map);
1241 }
1242
1243 static void s3c2410_dma_resume(void)
1244 {
1245 struct s3c2410_dma_chan *cp = s3c2410_chans + dma_channels - 1;
1246 int channel;
1247
1248 for (channel = dma_channels - 1; channel >= 0; cp--, channel--)
1249 s3c2410_dma_resume_chan(cp);
1250 }
1251
1252 #else
1253 #define s3c2410_dma_suspend NULL
1254 #define s3c2410_dma_resume NULL
1255 #endif /* CONFIG_PM */
1256
1257 struct syscore_ops dma_syscore_ops = {
1258 .suspend = s3c2410_dma_suspend,
1259 .resume = s3c2410_dma_resume,
1260 };
1261
1262 /* kmem cache implementation */
1263
1264 static void s3c2410_dma_cache_ctor(void *p)
1265 {
1266 memset(p, 0, sizeof(struct s3c2410_dma_buf));
1267 }
1268
1269 /* initialisation code */
1270
1271 static int __init s3c24xx_dma_syscore_init(void)
1272 {
1273 register_syscore_ops(&dma_syscore_ops);
1274
1275 return 0;
1276 }
1277
1278 late_initcall(s3c24xx_dma_syscore_init);
1279
1280 int __init s3c24xx_dma_init(unsigned int channels, unsigned int irq,
1281 unsigned int stride)
1282 {
1283 struct s3c2410_dma_chan *cp;
1284 int channel;
1285 int ret;
1286
1287 printk("S3C24XX DMA Driver, Copyright 2003-2006 Simtec Electronics\n");
1288
1289 dma_channels = channels;
1290
1291 dma_base = ioremap(S3C24XX_PA_DMA, stride * channels);
1292 if (dma_base == NULL) {
1293 printk(KERN_ERR "dma failed to remap register block\n");
1294 return -ENOMEM;
1295 }
1296
1297 dma_kmem = kmem_cache_create("dma_desc",
1298 sizeof(struct s3c2410_dma_buf), 0,
1299 SLAB_HWCACHE_ALIGN,
1300 s3c2410_dma_cache_ctor);
1301
1302 if (dma_kmem == NULL) {
1303 printk(KERN_ERR "dma failed to make kmem cache\n");
1304 ret = -ENOMEM;
1305 goto err;
1306 }
1307
1308 for (channel = 0; channel < channels; channel++) {
1309 cp = &s3c2410_chans[channel];
1310
1311 memset(cp, 0, sizeof(struct s3c2410_dma_chan));
1312
1313 /* dma channel irqs are in order.. */
1314 cp->number = channel;
1315 cp->irq = channel + irq;
1316 cp->regs = dma_base + (channel * stride);
1317
1318 /* point current stats somewhere */
1319 cp->stats = &cp->stats_store;
1320 cp->stats_store.timeout_shortest = LONG_MAX;
1321
1322 /* basic channel configuration */
1323
1324 cp->load_timeout = 1<<18;
1325
1326 printk("DMA channel %d at %p, irq %d\n",
1327 cp->number, cp->regs, cp->irq);
1328 }
1329
1330 return 0;
1331
1332 err:
1333 kmem_cache_destroy(dma_kmem);
1334 iounmap(dma_base);
1335 dma_base = NULL;
1336 return ret;
1337 }
1338
1339 int __init s3c2410_dma_init(void)
1340 {
1341 return s3c24xx_dma_init(4, IRQ_DMA0, 0x40);
1342 }
1343
1344 static inline int is_channel_valid(unsigned int channel)
1345 {
1346 return (channel & DMA_CH_VALID);
1347 }
1348
1349 static struct s3c24xx_dma_order *dma_order;
1350
1351
1352 /* s3c2410_dma_map_channel()
1353 *
1354 * turn the virtual channel number into a real, and un-used hardware
1355 * channel.
1356 *
1357 * first, try the dma ordering given to us by either the relevant
1358 * dma code, or the board. Then just find the first usable free
1359 * channel
1360 */
1361
1362 static struct s3c2410_dma_chan *s3c2410_dma_map_channel(int channel)
1363 {
1364 struct s3c24xx_dma_order_ch *ord = NULL;
1365 struct s3c24xx_dma_map *ch_map;
1366 struct s3c2410_dma_chan *dmach;
1367 int ch;
1368
1369 if (dma_sel.map == NULL || channel > dma_sel.map_size)
1370 return NULL;
1371
1372 ch_map = dma_sel.map + channel;
1373
1374 /* first, try the board mapping */
1375
1376 if (dma_order) {
1377 ord = &dma_order->channels[channel];
1378
1379 for (ch = 0; ch < dma_channels; ch++) {
1380 int tmp;
1381 if (!is_channel_valid(ord->list[ch]))
1382 continue;
1383
1384 tmp = ord->list[ch] & ~DMA_CH_VALID;
1385 if (s3c2410_chans[tmp].in_use == 0) {
1386 ch = tmp;
1387 goto found;
1388 }
1389 }
1390
1391 if (ord->flags & DMA_CH_NEVER)
1392 return NULL;
1393 }
1394
1395 /* second, search the channel map for first free */
1396
1397 for (ch = 0; ch < dma_channels; ch++) {
1398 if (!is_channel_valid(ch_map->channels[ch]))
1399 continue;
1400
1401 if (s3c2410_chans[ch].in_use == 0) {
1402 printk("mapped channel %d to %d\n", channel, ch);
1403 break;
1404 }
1405 }
1406
1407 if (ch >= dma_channels)
1408 return NULL;
1409
1410 /* update our channel mapping */
1411
1412 found:
1413 dmach = &s3c2410_chans[ch];
1414 dmach->map = ch_map;
1415 dmach->req_ch = channel;
1416 s3c_dma_chan_map[channel] = dmach;
1417
1418 /* select the channel */
1419
1420 (dma_sel.select)(dmach, ch_map);
1421
1422 return dmach;
1423 }
1424
1425 static int s3c24xx_dma_check_entry(struct s3c24xx_dma_map *map, int ch)
1426 {
1427 return 0;
1428 }
1429
1430 int __init s3c24xx_dma_init_map(struct s3c24xx_dma_selection *sel)
1431 {
1432 struct s3c24xx_dma_map *nmap;
1433 size_t map_sz = sizeof(*nmap) * sel->map_size;
1434 int ptr;
1435
1436 nmap = kmemdup(sel->map, map_sz, GFP_KERNEL);
1437 if (nmap == NULL)
1438 return -ENOMEM;
1439
1440 memcpy(&dma_sel, sel, sizeof(*sel));
1441
1442 dma_sel.map = nmap;
1443
1444 for (ptr = 0; ptr < sel->map_size; ptr++)
1445 s3c24xx_dma_check_entry(nmap+ptr, ptr);
1446
1447 return 0;
1448 }
1449
1450 int __init s3c24xx_dma_order_set(struct s3c24xx_dma_order *ord)
1451 {
1452 struct s3c24xx_dma_order *nord = dma_order;
1453
1454 if (nord == NULL)
1455 nord = kmalloc(sizeof(struct s3c24xx_dma_order), GFP_KERNEL);
1456
1457 if (nord == NULL) {
1458 printk(KERN_ERR "no memory to store dma channel order\n");
1459 return -ENOMEM;
1460 }
1461
1462 dma_order = nord;
1463 memcpy(nord, ord, sizeof(struct s3c24xx_dma_order));
1464 return 0;
1465 }
1466
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