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diff --git a/arch/arm/plat-s3c24xx/dma.c b/arch/arm/plat-s3c24xx/dma.c
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1/* linux/arch/arm/plat-s3c24xx/dma.c
2 *
3 * Copyright (c) 2003-2005,2006 Simtec Electronics
4 * Ben Dooks <ben@simtec.co.uk>
5 *
6 * S3C2410 DMA core
7 *
8 * http://armlinux.simtec.co.uk/
9 *
10 * This program is free software; you can redistribute it and/or modify
11 * it under the terms of the GNU General Public License version 2 as
12 * published by the Free Software Foundation.
13*/
14
15
16#ifdef CONFIG_S3C2410_DMA_DEBUG
17#define DEBUG
18#endif
19
20#include <linux/module.h>
21#include <linux/init.h>
22#include <linux/sched.h>
23#include <linux/spinlock.h>
24#include <linux/interrupt.h>
25#include <linux/sysdev.h>
26#include <linux/slab.h>
27#include <linux/errno.h>
28#include <linux/delay.h>
29
30#include <asm/system.h>
31#include <asm/irq.h>
32#include <asm/hardware.h>
33#include <asm/io.h>
34#include <asm/dma.h>
35
36#include <asm/mach/dma.h>
37#include <asm/arch/map.h>
38
39#include <asm/plat-s3c24xx/dma.h>
40
41/* io map for dma */
42static void __iomem *dma_base;
43static struct kmem_cache *dma_kmem;
44
45struct s3c24xx_dma_selection dma_sel;
46
47/* dma channel state information */
48struct s3c2410_dma_chan s3c2410_chans[S3C2410_DMA_CHANNELS];
49
50/* debugging functions */
51
52#define BUF_MAGIC (0xcafebabe)
53
54#define dmawarn(fmt...) printk(KERN_DEBUG fmt)
55
56#define dma_regaddr(chan, reg) ((chan)->regs + (reg))
57
58#if 1
59#define dma_wrreg(chan, reg, val) writel((val), (chan)->regs + (reg))
60#else
61static inline void
62dma_wrreg(struct s3c2410_dma_chan *chan, int reg, unsigned long val)
63{
64 pr_debug("writing %08x to register %08x\n",(unsigned int)val,reg);
65 writel(val, dma_regaddr(chan, reg));
66}
67#endif
68
69#define dma_rdreg(chan, reg) readl((chan)->regs + (reg))
70
71/* captured register state for debug */
72
73struct s3c2410_dma_regstate {
74 unsigned long dcsrc;
75 unsigned long disrc;
76 unsigned long dstat;
77 unsigned long dcon;
78 unsigned long dmsktrig;
79};
80
81#ifdef CONFIG_S3C2410_DMA_DEBUG
82
83/* dmadbg_showregs
84 *
85 * simple debug routine to print the current state of the dma registers
86*/
87
88static void
89dmadbg_capture(struct s3c2410_dma_chan *chan, struct s3c2410_dma_regstate *regs)
90{
91 regs->dcsrc = dma_rdreg(chan, S3C2410_DMA_DCSRC);
92 regs->disrc = dma_rdreg(chan, S3C2410_DMA_DISRC);
93 regs->dstat = dma_rdreg(chan, S3C2410_DMA_DSTAT);
94 regs->dcon = dma_rdreg(chan, S3C2410_DMA_DCON);
95 regs->dmsktrig = dma_rdreg(chan, S3C2410_DMA_DMASKTRIG);
96}
97
98static void
99dmadbg_dumpregs(const char *fname, int line, struct s3c2410_dma_chan *chan,
100 struct s3c2410_dma_regstate *regs)
101{
102 printk(KERN_DEBUG "dma%d: %s:%d: DCSRC=%08lx, DISRC=%08lx, DSTAT=%08lx DMT=%02lx, DCON=%08lx\n",
103 chan->number, fname, line,
104 regs->dcsrc, regs->disrc, regs->dstat, regs->dmsktrig,
105 regs->dcon);
106}
107
108static void
109dmadbg_showchan(const char *fname, int line, struct s3c2410_dma_chan *chan)
110{
111 struct s3c2410_dma_regstate state;
112
113 dmadbg_capture(chan, &state);
114
115 printk(KERN_DEBUG "dma%d: %s:%d: ls=%d, cur=%p, %p %p\n",
116 chan->number, fname, line, chan->load_state,
117 chan->curr, chan->next, chan->end);
118
119 dmadbg_dumpregs(fname, line, chan, &state);
120}
121
122static void
123dmadbg_showregs(const char *fname, int line, struct s3c2410_dma_chan *chan)
124{
125 struct s3c2410_dma_regstate state;
126
127 dmadbg_capture(chan, &state);
128 dmadbg_dumpregs(fname, line, chan, &state);
129}
130
131#define dbg_showregs(chan) dmadbg_showregs(__FUNCTION__, __LINE__, (chan))
132#define dbg_showchan(chan) dmadbg_showchan(__FUNCTION__, __LINE__, (chan))
133#else
134#define dbg_showregs(chan) do { } while(0)
135#define dbg_showchan(chan) do { } while(0)
136#endif /* CONFIG_S3C2410_DMA_DEBUG */
137
138static struct s3c2410_dma_chan *dma_chan_map[DMACH_MAX];
139
140/* lookup_dma_channel
141 *
142 * change the dma channel number given into a real dma channel id
143*/
144
145static struct s3c2410_dma_chan *lookup_dma_channel(unsigned int channel)
146{
147 if (channel & DMACH_LOW_LEVEL)
148 return &s3c2410_chans[channel & ~DMACH_LOW_LEVEL];
149 else
150 return dma_chan_map[channel];
151}
152
153/* s3c2410_dma_stats_timeout
154 *
155 * Update DMA stats from timeout info
156*/
157
158static void
159s3c2410_dma_stats_timeout(struct s3c2410_dma_stats *stats, int val)
160{
161 if (stats == NULL)
162 return;
163
164 if (val > stats->timeout_longest)
165 stats->timeout_longest = val;
166 if (val < stats->timeout_shortest)
167 stats->timeout_shortest = val;
168
169 stats->timeout_avg += val;
170}
171
172/* s3c2410_dma_waitforload
173 *
174 * wait for the DMA engine to load a buffer, and update the state accordingly
175*/
176
177static int
178s3c2410_dma_waitforload(struct s3c2410_dma_chan *chan, int line)
179{
180 int timeout = chan->load_timeout;
181 int took;
182
183 if (chan->load_state != S3C2410_DMALOAD_1LOADED) {
184 printk(KERN_ERR "dma%d: s3c2410_dma_waitforload() called in loadstate %d from line %d\n", chan->number, chan->load_state, line);
185 return 0;
186 }
187
188 if (chan->stats != NULL)
189 chan->stats->loads++;
190
191 while (--timeout > 0) {
192 if ((dma_rdreg(chan, S3C2410_DMA_DSTAT) << (32-20)) != 0) {
193 took = chan->load_timeout - timeout;
194
195 s3c2410_dma_stats_timeout(chan->stats, took);
196
197 switch (chan->load_state) {
198 case S3C2410_DMALOAD_1LOADED:
199 chan->load_state = S3C2410_DMALOAD_1RUNNING;
200 break;
201
202 default:
203 printk(KERN_ERR "dma%d: unknown load_state in s3c2410_dma_waitforload() %d\n", chan->number, chan->load_state);
204 }
205
206 return 1;
207 }
208 }
209
210 if (chan->stats != NULL) {
211 chan->stats->timeout_failed++;
212 }
213
214 return 0;
215}
216
217
218
219/* s3c2410_dma_loadbuffer
220 *
221 * load a buffer, and update the channel state
222*/
223
224static inline int
225s3c2410_dma_loadbuffer(struct s3c2410_dma_chan *chan,
226 struct s3c2410_dma_buf *buf)
227{
228 unsigned long reload;
229
230 pr_debug("s3c2410_chan_loadbuffer: loading buff %p (0x%08lx,0x%06x)\n",
231 buf, (unsigned long)buf->data, buf->size);
232
233 if (buf == NULL) {
234 dmawarn("buffer is NULL\n");
235 return -EINVAL;
236 }
237
238 /* check the state of the channel before we do anything */
239
240 if (chan->load_state == S3C2410_DMALOAD_1LOADED) {
241 dmawarn("load_state is S3C2410_DMALOAD_1LOADED\n");
242 }
243
244 if (chan->load_state == S3C2410_DMALOAD_1LOADED_1RUNNING) {
245 dmawarn("state is S3C2410_DMALOAD_1LOADED_1RUNNING\n");
246 }
247
248 /* it would seem sensible if we are the last buffer to not bother
249 * with the auto-reload bit, so that the DMA engine will not try
250 * and load another transfer after this one has finished...
251 */
252 if (chan->load_state == S3C2410_DMALOAD_NONE) {
253 pr_debug("load_state is none, checking for noreload (next=%p)\n",
254 buf->next);
255 reload = (buf->next == NULL) ? S3C2410_DCON_NORELOAD : 0;
256 } else {
257 //pr_debug("load_state is %d => autoreload\n", chan->load_state);
258 reload = S3C2410_DCON_AUTORELOAD;
259 }
260
261 if ((buf->data & 0xf0000000) != 0x30000000) {
262 dmawarn("dmaload: buffer is %p\n", (void *)buf->data);
263 }
264
265 writel(buf->data, chan->addr_reg);
266
267 dma_wrreg(chan, S3C2410_DMA_DCON,
268 chan->dcon | reload | (buf->size/chan->xfer_unit));
269
270 chan->next = buf->next;
271
272 /* update the state of the channel */
273
274 switch (chan->load_state) {
275 case S3C2410_DMALOAD_NONE:
276 chan->load_state = S3C2410_DMALOAD_1LOADED;
277 break;
278
279 case S3C2410_DMALOAD_1RUNNING:
280 chan->load_state = S3C2410_DMALOAD_1LOADED_1RUNNING;
281 break;
282
283 default:
284 dmawarn("dmaload: unknown state %d in loadbuffer\n",
285 chan->load_state);
286 break;
287 }
288
289 return 0;
290}
291
292/* s3c2410_dma_call_op
293 *
294 * small routine to call the op routine with the given op if it has been
295 * registered
296*/
297
298static void
299s3c2410_dma_call_op(struct s3c2410_dma_chan *chan, enum s3c2410_chan_op op)
300{
301 if (chan->op_fn != NULL) {
302 (chan->op_fn)(chan, op);
303 }
304}
305
306/* s3c2410_dma_buffdone
307 *
308 * small wrapper to check if callback routine needs to be called, and
309 * if so, call it
310*/
311
312static inline void
313s3c2410_dma_buffdone(struct s3c2410_dma_chan *chan, struct s3c2410_dma_buf *buf,
314 enum s3c2410_dma_buffresult result)
315{
316#if 0
317 pr_debug("callback_fn=%p, buf=%p, id=%p, size=%d, result=%d\n",
318 chan->callback_fn, buf, buf->id, buf->size, result);
319#endif
320
321 if (chan->callback_fn != NULL) {
322 (chan->callback_fn)(chan, buf->id, buf->size, result);
323 }
324}
325
326/* s3c2410_dma_start
327 *
328 * start a dma channel going
329*/
330
331static int s3c2410_dma_start(struct s3c2410_dma_chan *chan)
332{
333 unsigned long tmp;
334 unsigned long flags;
335
336 pr_debug("s3c2410_start_dma: channel=%d\n", chan->number);
337
338 local_irq_save(flags);
339
340 if (chan->state == S3C2410_DMA_RUNNING) {
341 pr_debug("s3c2410_start_dma: already running (%d)\n", chan->state);
342 local_irq_restore(flags);
343 return 0;
344 }
345
346 chan->state = S3C2410_DMA_RUNNING;
347
348 /* check wether there is anything to load, and if not, see
349 * if we can find anything to load
350 */
351
352 if (chan->load_state == S3C2410_DMALOAD_NONE) {
353 if (chan->next == NULL) {
354 printk(KERN_ERR "dma%d: channel has nothing loaded\n",
355 chan->number);
356 chan->state = S3C2410_DMA_IDLE;
357 local_irq_restore(flags);
358 return -EINVAL;
359 }
360
361 s3c2410_dma_loadbuffer(chan, chan->next);
362 }
363
364 dbg_showchan(chan);
365
366 /* enable the channel */
367
368 if (!chan->irq_enabled) {
369 enable_irq(chan->irq);
370 chan->irq_enabled = 1;
371 }
372
373 /* start the channel going */
374
375 tmp = dma_rdreg(chan, S3C2410_DMA_DMASKTRIG);
376 tmp &= ~S3C2410_DMASKTRIG_STOP;
377 tmp |= S3C2410_DMASKTRIG_ON;
378 dma_wrreg(chan, S3C2410_DMA_DMASKTRIG, tmp);
379
380 pr_debug("dma%d: %08lx to DMASKTRIG\n", chan->number, tmp);
381
382#if 0
383 /* the dma buffer loads should take care of clearing the AUTO
384 * reloading feature */
385 tmp = dma_rdreg(chan, S3C2410_DMA_DCON);
386 tmp &= ~S3C2410_DCON_NORELOAD;
387 dma_wrreg(chan, S3C2410_DMA_DCON, tmp);
388#endif
389
390 s3c2410_dma_call_op(chan, S3C2410_DMAOP_START);
391
392 dbg_showchan(chan);
393
394 /* if we've only loaded one buffer onto the channel, then chec
395 * to see if we have another, and if so, try and load it so when
396 * the first buffer is finished, the new one will be loaded onto
397 * the channel */
398
399 if (chan->next != NULL) {
400 if (chan->load_state == S3C2410_DMALOAD_1LOADED) {
401
402 if (s3c2410_dma_waitforload(chan, __LINE__) == 0) {
403 pr_debug("%s: buff not yet loaded, no more todo\n",
404 __FUNCTION__);
405 } else {
406 chan->load_state = S3C2410_DMALOAD_1RUNNING;
407 s3c2410_dma_loadbuffer(chan, chan->next);
408 }
409
410 } else if (chan->load_state == S3C2410_DMALOAD_1RUNNING) {
411 s3c2410_dma_loadbuffer(chan, chan->next);
412 }
413 }
414
415
416 local_irq_restore(flags);
417
418 return 0;
419}
420
421/* s3c2410_dma_canload
422 *
423 * work out if we can queue another buffer into the DMA engine
424*/
425
426static int
427s3c2410_dma_canload(struct s3c2410_dma_chan *chan)
428{
429 if (chan->load_state == S3C2410_DMALOAD_NONE ||
430 chan->load_state == S3C2410_DMALOAD_1RUNNING)
431 return 1;
432
433 return 0;
434}
435
436/* s3c2410_dma_enqueue
437 *
438 * queue an given buffer for dma transfer.
439 *
440 * id the device driver's id information for this buffer
441 * data the physical address of the buffer data
442 * size the size of the buffer in bytes
443 *
444 * If the channel is not running, then the flag S3C2410_DMAF_AUTOSTART
445 * is checked, and if set, the channel is started. If this flag isn't set,
446 * then an error will be returned.
447 *
448 * It is possible to queue more than one DMA buffer onto a channel at
449 * once, and the code will deal with the re-loading of the next buffer
450 * when necessary.
451*/
452
453int s3c2410_dma_enqueue(unsigned int channel, void *id,
454 dma_addr_t data, int size)
455{
456 struct s3c2410_dma_chan *chan = lookup_dma_channel(channel);
457 struct s3c2410_dma_buf *buf;
458 unsigned long flags;
459
460 if (chan == NULL)
461 return -EINVAL;
462
463 pr_debug("%s: id=%p, data=%08x, size=%d\n",
464 __FUNCTION__, id, (unsigned int)data, size);
465
466 buf = kmem_cache_alloc(dma_kmem, GFP_ATOMIC);
467 if (buf == NULL) {
468 pr_debug("%s: out of memory (%ld alloc)\n",
469 __FUNCTION__, (long)sizeof(*buf));
470 return -ENOMEM;
471 }
472
473 //pr_debug("%s: new buffer %p\n", __FUNCTION__, buf);
474 //dbg_showchan(chan);
475
476 buf->next = NULL;
477 buf->data = buf->ptr = data;
478 buf->size = size;
479 buf->id = id;
480 buf->magic = BUF_MAGIC;
481
482 local_irq_save(flags);
483
484 if (chan->curr == NULL) {
485 /* we've got nothing loaded... */
486 pr_debug("%s: buffer %p queued onto empty channel\n",
487 __FUNCTION__, buf);
488
489 chan->curr = buf;
490 chan->end = buf;
491 chan->next = NULL;
492 } else {
493 pr_debug("dma%d: %s: buffer %p queued onto non-empty channel\n",
494 chan->number, __FUNCTION__, buf);
495
496 if (chan->end == NULL)
497 pr_debug("dma%d: %s: %p not empty, and chan->end==NULL?\n",
498 chan->number, __FUNCTION__, chan);
499
500 chan->end->next = buf;
501 chan->end = buf;
502 }
503
504 /* if necessary, update the next buffer field */
505 if (chan->next == NULL)
506 chan->next = buf;
507
508 /* check to see if we can load a buffer */
509 if (chan->state == S3C2410_DMA_RUNNING) {
510 if (chan->load_state == S3C2410_DMALOAD_1LOADED && 1) {
511 if (s3c2410_dma_waitforload(chan, __LINE__) == 0) {
512 printk(KERN_ERR "dma%d: loadbuffer:"
513 "timeout loading buffer\n",
514 chan->number);
515 dbg_showchan(chan);
516 local_irq_restore(flags);
517 return -EINVAL;
518 }
519 }
520
521 while (s3c2410_dma_canload(chan) && chan->next != NULL) {
522 s3c2410_dma_loadbuffer(chan, chan->next);
523 }
524 } else if (chan->state == S3C2410_DMA_IDLE) {
525 if (chan->flags & S3C2410_DMAF_AUTOSTART) {
526 s3c2410_dma_ctrl(chan->number, S3C2410_DMAOP_START);
527 }
528 }
529
530 local_irq_restore(flags);
531 return 0;
532}
533
534EXPORT_SYMBOL(s3c2410_dma_enqueue);
535
536static inline void
537s3c2410_dma_freebuf(struct s3c2410_dma_buf *buf)
538{
539 int magicok = (buf->magic == BUF_MAGIC);
540
541 buf->magic = -1;
542
543 if (magicok) {
544 kmem_cache_free(dma_kmem, buf);
545 } else {
546 printk("s3c2410_dma_freebuf: buff %p with bad magic\n", buf);
547 }
548}
549
550/* s3c2410_dma_lastxfer
551 *
552 * called when the system is out of buffers, to ensure that the channel
553 * is prepared for shutdown.
554*/
555
556static inline void
557s3c2410_dma_lastxfer(struct s3c2410_dma_chan *chan)
558{
559#if 0
560 pr_debug("dma%d: s3c2410_dma_lastxfer: load_state %d\n",
561 chan->number, chan->load_state);
562#endif
563
564 switch (chan->load_state) {
565 case S3C2410_DMALOAD_NONE:
566 break;
567
568 case S3C2410_DMALOAD_1LOADED:
569 if (s3c2410_dma_waitforload(chan, __LINE__) == 0) {
570 /* flag error? */
571 printk(KERN_ERR "dma%d: timeout waiting for load (%s)\n",
572 chan->number, __FUNCTION__);
573 return;
574 }
575 break;
576
577 case S3C2410_DMALOAD_1LOADED_1RUNNING:
578 /* I belive in this case we do not have anything to do
579 * until the next buffer comes along, and we turn off the
580 * reload */
581 return;
582
583 default:
584 pr_debug("dma%d: lastxfer: unhandled load_state %d with no next\n",
585 chan->number, chan->load_state);
586 return;
587
588 }
589
590 /* hopefully this'll shut the damned thing up after the transfer... */
591 dma_wrreg(chan, S3C2410_DMA_DCON, chan->dcon | S3C2410_DCON_NORELOAD);
592}
593
594
595#define dmadbg2(x...)
596
597static irqreturn_t
598s3c2410_dma_irq(int irq, void *devpw)
599{
600 struct s3c2410_dma_chan *chan = (struct s3c2410_dma_chan *)devpw;
601 struct s3c2410_dma_buf *buf;
602
603 buf = chan->curr;
604
605 dbg_showchan(chan);
606
607 /* modify the channel state */
608
609 switch (chan->load_state) {
610 case S3C2410_DMALOAD_1RUNNING:
611 /* TODO - if we are running only one buffer, we probably
612 * want to reload here, and then worry about the buffer
613 * callback */
614
615 chan->load_state = S3C2410_DMALOAD_NONE;
616 break;
617
618 case S3C2410_DMALOAD_1LOADED:
619 /* iirc, we should go back to NONE loaded here, we
620 * had a buffer, and it was never verified as being
621 * loaded.
622 */
623
624 chan->load_state = S3C2410_DMALOAD_NONE;
625 break;
626
627 case S3C2410_DMALOAD_1LOADED_1RUNNING:
628 /* we'll worry about checking to see if another buffer is
629 * ready after we've called back the owner. This should
630 * ensure we do not wait around too long for the DMA
631 * engine to start the next transfer
632 */
633
634 chan->load_state = S3C2410_DMALOAD_1LOADED;
635 break;
636
637 case S3C2410_DMALOAD_NONE:
638 printk(KERN_ERR "dma%d: IRQ with no loaded buffer?\n",
639 chan->number);
640 break;
641
642 default:
643 printk(KERN_ERR "dma%d: IRQ in invalid load_state %d\n",
644 chan->number, chan->load_state);
645 break;
646 }
647
648 if (buf != NULL) {
649 /* update the chain to make sure that if we load any more
650 * buffers when we call the callback function, things should
651 * work properly */
652
653 chan->curr = buf->next;
654 buf->next = NULL;
655
656 if (buf->magic != BUF_MAGIC) {
657 printk(KERN_ERR "dma%d: %s: buf %p incorrect magic\n",
658 chan->number, __FUNCTION__, buf);
659 return IRQ_HANDLED;
660 }
661
662 s3c2410_dma_buffdone(chan, buf, S3C2410_RES_OK);
663
664 /* free resouces */
665 s3c2410_dma_freebuf(buf);
666 } else {
667 }
668
669 /* only reload if the channel is still running... our buffer done
670 * routine may have altered the state by requesting the dma channel
671 * to stop or shutdown... */
672
673 /* todo: check that when the channel is shut-down from inside this
674 * function, we cope with unsetting reload, etc */
675
676 if (chan->next != NULL && chan->state != S3C2410_DMA_IDLE) {
677 unsigned long flags;
678
679 switch (chan->load_state) {
680 case S3C2410_DMALOAD_1RUNNING:
681 /* don't need to do anything for this state */
682 break;
683
684 case S3C2410_DMALOAD_NONE:
685 /* can load buffer immediately */
686 break;
687
688 case S3C2410_DMALOAD_1LOADED:
689 if (s3c2410_dma_waitforload(chan, __LINE__) == 0) {
690 /* flag error? */
691 printk(KERN_ERR "dma%d: timeout waiting for load (%s)\n",
692 chan->number, __FUNCTION__);
693 return IRQ_HANDLED;
694 }
695
696 break;
697
698 case S3C2410_DMALOAD_1LOADED_1RUNNING:
699 goto no_load;
700
701 default:
702 printk(KERN_ERR "dma%d: unknown load_state in irq, %d\n",
703 chan->number, chan->load_state);
704 return IRQ_HANDLED;
705 }
706
707 local_irq_save(flags);
708 s3c2410_dma_loadbuffer(chan, chan->next);
709 local_irq_restore(flags);
710 } else {
711 s3c2410_dma_lastxfer(chan);
712
713 /* see if we can stop this channel.. */
714 if (chan->load_state == S3C2410_DMALOAD_NONE) {
715 pr_debug("dma%d: end of transfer, stopping channel (%ld)\n",
716 chan->number, jiffies);
717 s3c2410_dma_ctrl(chan->number | DMACH_LOW_LEVEL,
718 S3C2410_DMAOP_STOP);
719 }
720 }
721
722 no_load:
723 return IRQ_HANDLED;
724}
725
726static struct s3c2410_dma_chan *s3c2410_dma_map_channel(int channel);
727
728/* s3c2410_request_dma
729 *
730 * get control of an dma channel
731*/
732
733int s3c2410_dma_request(unsigned int channel,
734 struct s3c2410_dma_client *client,
735 void *dev)
736{
737 struct s3c2410_dma_chan *chan;
738 unsigned long flags;
739 int err;
740
741 pr_debug("dma%d: s3c2410_request_dma: client=%s, dev=%p\n",
742 channel, client->name, dev);
743
744 local_irq_save(flags);
745
746 chan = s3c2410_dma_map_channel(channel);
747 if (chan == NULL) {
748 local_irq_restore(flags);
749 return -EBUSY;
750 }
751
752 dbg_showchan(chan);
753
754 chan->client = client;
755 chan->in_use = 1;
756
757 if (!chan->irq_claimed) {
758 pr_debug("dma%d: %s : requesting irq %d\n",
759 channel, __FUNCTION__, chan->irq);
760
761 chan->irq_claimed = 1;
762 local_irq_restore(flags);
763
764 err = request_irq(chan->irq, s3c2410_dma_irq, IRQF_DISABLED,
765 client->name, (void *)chan);
766
767 local_irq_save(flags);
768
769 if (err) {
770 chan->in_use = 0;
771 chan->irq_claimed = 0;
772 local_irq_restore(flags);
773
774 printk(KERN_ERR "%s: cannot get IRQ %d for DMA %d\n",
775 client->name, chan->irq, chan->number);
776 return err;
777 }
778
779 chan->irq_enabled = 1;
780 }
781
782 local_irq_restore(flags);
783
784 /* need to setup */
785
786 pr_debug("%s: channel initialised, %p\n", __FUNCTION__, chan);
787
788 return 0;
789}
790
791EXPORT_SYMBOL(s3c2410_dma_request);
792
793/* s3c2410_dma_free
794 *
795 * release the given channel back to the system, will stop and flush
796 * any outstanding transfers, and ensure the channel is ready for the
797 * next claimant.
798 *
799 * Note, although a warning is currently printed if the freeing client
800 * info is not the same as the registrant's client info, the free is still
801 * allowed to go through.
802*/
803
804int s3c2410_dma_free(dmach_t channel, struct s3c2410_dma_client *client)
805{
806 struct s3c2410_dma_chan *chan = lookup_dma_channel(channel);
807 unsigned long flags;
808
809 if (chan == NULL)
810 return -EINVAL;
811
812 local_irq_save(flags);
813
814 if (chan->client != client) {
815 printk(KERN_WARNING "dma%d: possible free from different client (channel %p, passed %p)\n",
816 channel, chan->client, client);
817 }
818
819 /* sort out stopping and freeing the channel */
820
821 if (chan->state != S3C2410_DMA_IDLE) {
822 pr_debug("%s: need to stop dma channel %p\n",
823 __FUNCTION__, chan);
824
825 /* possibly flush the channel */
826 s3c2410_dma_ctrl(channel, S3C2410_DMAOP_STOP);
827 }
828
829 chan->client = NULL;
830 chan->in_use = 0;
831
832 if (chan->irq_claimed)
833 free_irq(chan->irq, (void *)chan);
834
835 chan->irq_claimed = 0;
836
837 if (!(channel & DMACH_LOW_LEVEL))
838 dma_chan_map[channel] = NULL;
839
840 local_irq_restore(flags);
841
842 return 0;
843}
844
845EXPORT_SYMBOL(s3c2410_dma_free);
846
847static int s3c2410_dma_dostop(struct s3c2410_dma_chan *chan)
848{
849 unsigned long flags;
850 unsigned long tmp;
851
852 pr_debug("%s:\n", __FUNCTION__);
853
854 dbg_showchan(chan);
855
856 local_irq_save(flags);
857
858 s3c2410_dma_call_op(chan, S3C2410_DMAOP_STOP);
859
860 tmp = dma_rdreg(chan, S3C2410_DMA_DMASKTRIG);
861 tmp |= S3C2410_DMASKTRIG_STOP;
862 //tmp &= ~S3C2410_DMASKTRIG_ON;
863 dma_wrreg(chan, S3C2410_DMA_DMASKTRIG, tmp);
864
865#if 0
866 /* should also clear interrupts, according to WinCE BSP */
867 tmp = dma_rdreg(chan, S3C2410_DMA_DCON);
868 tmp |= S3C2410_DCON_NORELOAD;
869 dma_wrreg(chan, S3C2410_DMA_DCON, tmp);
870#endif
871
872 /* should stop do this, or should we wait for flush? */
873 chan->state = S3C2410_DMA_IDLE;
874 chan->load_state = S3C2410_DMALOAD_NONE;
875
876 local_irq_restore(flags);
877
878 return 0;
879}
880
881void s3c2410_dma_waitforstop(struct s3c2410_dma_chan *chan)
882{
883 unsigned long tmp;
884 unsigned int timeout = 0x10000;
885
886 while (timeout-- > 0) {
887 tmp = dma_rdreg(chan, S3C2410_DMA_DMASKTRIG);
888
889 if (!(tmp & S3C2410_DMASKTRIG_ON))
890 return;
891 }
892
893 pr_debug("dma%d: failed to stop?\n", chan->number);
894}
895
896
897/* s3c2410_dma_flush
898 *
899 * stop the channel, and remove all current and pending transfers
900*/
901
902static int s3c2410_dma_flush(struct s3c2410_dma_chan *chan)
903{
904 struct s3c2410_dma_buf *buf, *next;
905 unsigned long flags;
906
907 pr_debug("%s: chan %p (%d)\n", __FUNCTION__, chan, chan->number);
908
909 dbg_showchan(chan);
910
911 local_irq_save(flags);
912
913 if (chan->state != S3C2410_DMA_IDLE) {
914 pr_debug("%s: stopping channel...\n", __FUNCTION__ );
915 s3c2410_dma_ctrl(chan->number, S3C2410_DMAOP_STOP);
916 }
917
918 buf = chan->curr;
919 if (buf == NULL)
920 buf = chan->next;
921
922 chan->curr = chan->next = chan->end = NULL;
923
924 if (buf != NULL) {
925 for ( ; buf != NULL; buf = next) {
926 next = buf->next;
927
928 pr_debug("%s: free buffer %p, next %p\n",
929 __FUNCTION__, buf, buf->next);
930
931 s3c2410_dma_buffdone(chan, buf, S3C2410_RES_ABORT);
932 s3c2410_dma_freebuf(buf);
933 }
934 }
935
936 dbg_showregs(chan);
937
938 s3c2410_dma_waitforstop(chan);
939
940#if 0
941 /* should also clear interrupts, according to WinCE BSP */
942 {
943 unsigned long tmp;
944
945 tmp = dma_rdreg(chan, S3C2410_DMA_DCON);
946 tmp |= S3C2410_DCON_NORELOAD;
947 dma_wrreg(chan, S3C2410_DMA_DCON, tmp);
948 }
949#endif
950
951 dbg_showregs(chan);
952
953 local_irq_restore(flags);
954
955 return 0;
956}
957
958int
959s3c2410_dma_started(struct s3c2410_dma_chan *chan)
960{
961 unsigned long flags;
962
963 local_irq_save(flags);
964
965 dbg_showchan(chan);
966
967 /* if we've only loaded one buffer onto the channel, then chec
968 * to see if we have another, and if so, try and load it so when
969 * the first buffer is finished, the new one will be loaded onto
970 * the channel */
971
972 if (chan->next != NULL) {
973 if (chan->load_state == S3C2410_DMALOAD_1LOADED) {
974
975 if (s3c2410_dma_waitforload(chan, __LINE__) == 0) {
976 pr_debug("%s: buff not yet loaded, no more todo\n",
977 __FUNCTION__);
978 } else {
979 chan->load_state = S3C2410_DMALOAD_1RUNNING;
980 s3c2410_dma_loadbuffer(chan, chan->next);
981 }
982
983 } else if (chan->load_state == S3C2410_DMALOAD_1RUNNING) {
984 s3c2410_dma_loadbuffer(chan, chan->next);
985 }
986 }
987
988
989 local_irq_restore(flags);
990
991 return 0;
992
993}
994
995int
996s3c2410_dma_ctrl(dmach_t channel, enum s3c2410_chan_op op)
997{
998 struct s3c2410_dma_chan *chan = lookup_dma_channel(channel);
999
1000 if (chan == NULL)
1001 return -EINVAL;
1002
1003 switch (op) {
1004 case S3C2410_DMAOP_START:
1005 return s3c2410_dma_start(chan);
1006
1007 case S3C2410_DMAOP_STOP:
1008 return s3c2410_dma_dostop(chan);
1009
1010 case S3C2410_DMAOP_PAUSE:
1011 case S3C2410_DMAOP_RESUME:
1012 return -ENOENT;
1013
1014 case S3C2410_DMAOP_FLUSH:
1015 return s3c2410_dma_flush(chan);
1016
1017 case S3C2410_DMAOP_STARTED:
1018 return s3c2410_dma_started(chan);
1019
1020 case S3C2410_DMAOP_TIMEOUT:
1021 return 0;
1022
1023 }
1024
1025 return -ENOENT; /* unknown, don't bother */
1026}
1027
1028EXPORT_SYMBOL(s3c2410_dma_ctrl);
1029
1030/* DMA configuration for each channel
1031 *
1032 * DISRCC -> source of the DMA (AHB,APB)
1033 * DISRC -> source address of the DMA
1034 * DIDSTC -> destination of the DMA (AHB,APD)
1035 * DIDST -> destination address of the DMA
1036*/
1037
1038/* s3c2410_dma_config
1039 *
1040 * xfersize: size of unit in bytes (1,2,4)
1041 * dcon: base value of the DCONx register
1042*/
1043
1044int s3c2410_dma_config(dmach_t channel,
1045 int xferunit,
1046 int dcon)
1047{
1048 struct s3c2410_dma_chan *chan = lookup_dma_channel(channel);
1049
1050 pr_debug("%s: chan=%d, xfer_unit=%d, dcon=%08x\n",
1051 __FUNCTION__, channel, xferunit, dcon);
1052
1053 if (chan == NULL)
1054 return -EINVAL;
1055
1056 pr_debug("%s: Initial dcon is %08x\n", __FUNCTION__, dcon);
1057
1058 dcon |= chan->dcon & dma_sel.dcon_mask;
1059
1060 pr_debug("%s: New dcon is %08x\n", __FUNCTION__, dcon);
1061
1062 switch (xferunit) {
1063 case 1:
1064 dcon |= S3C2410_DCON_BYTE;
1065 break;
1066
1067 case 2:
1068 dcon |= S3C2410_DCON_HALFWORD;
1069 break;
1070
1071 case 4:
1072 dcon |= S3C2410_DCON_WORD;
1073 break;
1074
1075 default:
1076 pr_debug("%s: bad transfer size %d\n", __FUNCTION__, xferunit);
1077 return -EINVAL;
1078 }
1079
1080 dcon |= S3C2410_DCON_HWTRIG;
1081 dcon |= S3C2410_DCON_INTREQ;
1082
1083 pr_debug("%s: dcon now %08x\n", __FUNCTION__, dcon);
1084
1085 chan->dcon = dcon;
1086 chan->xfer_unit = xferunit;
1087
1088 return 0;
1089}
1090
1091EXPORT_SYMBOL(s3c2410_dma_config);
1092
1093int s3c2410_dma_setflags(dmach_t channel, unsigned int flags)
1094{
1095 struct s3c2410_dma_chan *chan = lookup_dma_channel(channel);
1096
1097 if (chan == NULL)
1098 return -EINVAL;
1099
1100 pr_debug("%s: chan=%p, flags=%08x\n", __FUNCTION__, chan, flags);
1101
1102 chan->flags = flags;
1103
1104 return 0;
1105}
1106
1107EXPORT_SYMBOL(s3c2410_dma_setflags);
1108
1109
1110/* do we need to protect the settings of the fields from
1111 * irq?
1112*/
1113
1114int s3c2410_dma_set_opfn(dmach_t channel, s3c2410_dma_opfn_t rtn)
1115{
1116 struct s3c2410_dma_chan *chan = lookup_dma_channel(channel);
1117
1118 if (chan == NULL)
1119 return -EINVAL;
1120
1121 pr_debug("%s: chan=%p, op rtn=%p\n", __FUNCTION__, chan, rtn);
1122
1123 chan->op_fn = rtn;
1124
1125 return 0;
1126}
1127
1128EXPORT_SYMBOL(s3c2410_dma_set_opfn);
1129
1130int s3c2410_dma_set_buffdone_fn(dmach_t channel, s3c2410_dma_cbfn_t rtn)
1131{
1132 struct s3c2410_dma_chan *chan = lookup_dma_channel(channel);
1133
1134 if (chan == NULL)
1135 return -EINVAL;
1136
1137 pr_debug("%s: chan=%p, callback rtn=%p\n", __FUNCTION__, chan, rtn);
1138
1139 chan->callback_fn = rtn;
1140
1141 return 0;
1142}
1143
1144EXPORT_SYMBOL(s3c2410_dma_set_buffdone_fn);
1145
1146/* s3c2410_dma_devconfig
1147 *
1148 * configure the dma source/destination hardware type and address
1149 *
1150 * source: S3C2410_DMASRC_HW: source is hardware
1151 * S3C2410_DMASRC_MEM: source is memory
1152 *
1153 * hwcfg: the value for xxxSTCn register,
1154 * bit 0: 0=increment pointer, 1=leave pointer
1155 * bit 1: 0=soucre is AHB, 1=soucre is APB
1156 *
1157 * devaddr: physical address of the source
1158*/
1159
1160int s3c2410_dma_devconfig(int channel,
1161 enum s3c2410_dmasrc source,
1162 int hwcfg,
1163 unsigned long devaddr)
1164{
1165 struct s3c2410_dma_chan *chan = lookup_dma_channel(channel);
1166
1167 if (chan == NULL)
1168 return -EINVAL;
1169
1170 pr_debug("%s: source=%d, hwcfg=%08x, devaddr=%08lx\n",
1171 __FUNCTION__, (int)source, hwcfg, devaddr);
1172
1173 chan->source = source;
1174 chan->dev_addr = devaddr;
1175
1176 switch (source) {
1177 case S3C2410_DMASRC_HW:
1178 /* source is hardware */
1179 pr_debug("%s: hw source, devaddr=%08lx, hwcfg=%d\n",
1180 __FUNCTION__, devaddr, hwcfg);
1181 dma_wrreg(chan, S3C2410_DMA_DISRCC, hwcfg & 3);
1182 dma_wrreg(chan, S3C2410_DMA_DISRC, devaddr);
1183 dma_wrreg(chan, S3C2410_DMA_DIDSTC, (0<<1) | (0<<0));
1184
1185 chan->addr_reg = dma_regaddr(chan, S3C2410_DMA_DIDST);
1186 return 0;
1187
1188 case S3C2410_DMASRC_MEM:
1189 /* source is memory */
1190 pr_debug( "%s: mem source, devaddr=%08lx, hwcfg=%d\n",
1191 __FUNCTION__, devaddr, hwcfg);
1192 dma_wrreg(chan, S3C2410_DMA_DISRCC, (0<<1) | (0<<0));
1193 dma_wrreg(chan, S3C2410_DMA_DIDST, devaddr);
1194 dma_wrreg(chan, S3C2410_DMA_DIDSTC, hwcfg & 3);
1195
1196 chan->addr_reg = dma_regaddr(chan, S3C2410_DMA_DISRC);
1197 return 0;
1198 }
1199
1200 printk(KERN_ERR "dma%d: invalid source type (%d)\n", channel, source);
1201 return -EINVAL;
1202}
1203
1204EXPORT_SYMBOL(s3c2410_dma_devconfig);
1205
1206/* s3c2410_dma_getposition
1207 *
1208 * returns the current transfer points for the dma source and destination
1209*/
1210
1211int s3c2410_dma_getposition(dmach_t channel, dma_addr_t *src, dma_addr_t *dst)
1212{
1213 struct s3c2410_dma_chan *chan = lookup_dma_channel(channel);
1214
1215 if (chan == NULL)
1216 return -EINVAL;
1217
1218 if (src != NULL)
1219 *src = dma_rdreg(chan, S3C2410_DMA_DCSRC);
1220
1221 if (dst != NULL)
1222 *dst = dma_rdreg(chan, S3C2410_DMA_DCDST);
1223
1224 return 0;
1225}
1226
1227EXPORT_SYMBOL(s3c2410_dma_getposition);
1228
1229
1230/* system device class */
1231
1232#ifdef CONFIG_PM
1233
1234static int s3c2410_dma_suspend(struct sys_device *dev, pm_message_t state)
1235{
1236 struct s3c2410_dma_chan *cp = container_of(dev, struct s3c2410_dma_chan, dev);
1237
1238 printk(KERN_DEBUG "suspending dma channel %d\n", cp->number);
1239
1240 if (dma_rdreg(cp, S3C2410_DMA_DMASKTRIG) & S3C2410_DMASKTRIG_ON) {
1241 /* the dma channel is still working, which is probably
1242 * a bad thing to do over suspend/resume. We stop the
1243 * channel and assume that the client is either going to
1244 * retry after resume, or that it is broken.
1245 */
1246
1247 printk(KERN_INFO "dma: stopping channel %d due to suspend\n",
1248 cp->number);
1249
1250 s3c2410_dma_dostop(cp);
1251 }
1252
1253 return 0;
1254}
1255
1256static int s3c2410_dma_resume(struct sys_device *dev)
1257{
1258 return 0;
1259}
1260
1261#else
1262#define s3c2410_dma_suspend NULL
1263#define s3c2410_dma_resume NULL
1264#endif /* CONFIG_PM */
1265
1266struct sysdev_class dma_sysclass = {
1267 set_kset_name("s3c24xx-dma"),
1268 .suspend = s3c2410_dma_suspend,
1269 .resume = s3c2410_dma_resume,
1270};
1271
1272/* kmem cache implementation */
1273
1274static void s3c2410_dma_cache_ctor(void *p, struct kmem_cache *c, unsigned long f)
1275{
1276 memset(p, 0, sizeof(struct s3c2410_dma_buf));
1277}
1278
1279/* initialisation code */
1280
1281static int __init s3c2410_init_dma(void)
1282{
1283 struct s3c2410_dma_chan *cp;
1284 int channel;
1285 int ret;
1286
1287 printk("S3C24XX DMA Driver, (c) 2003-2004,2006 Simtec Electronics\n");
1288
1289 dma_base = ioremap(S3C24XX_PA_DMA, 0x200);
1290 if (dma_base == NULL) {
1291 printk(KERN_ERR "dma failed to remap register block\n");
1292 return -ENOMEM;
1293 }
1294
1295 printk("Registering sysclass\n");
1296
1297 ret = sysdev_class_register(&dma_sysclass);
1298 if (ret != 0) {
1299 printk(KERN_ERR "dma sysclass registration failed\n");
1300 goto err;
1301 }
1302
1303 dma_kmem = kmem_cache_create("dma_desc", sizeof(struct s3c2410_dma_buf), 0,
1304 SLAB_HWCACHE_ALIGN,
1305 s3c2410_dma_cache_ctor, NULL);
1306
1307 if (dma_kmem == NULL) {
1308 printk(KERN_ERR "dma failed to make kmem cache\n");
1309 ret = -ENOMEM;
1310 goto err;
1311 }
1312
1313 for (channel = 0; channel < S3C2410_DMA_CHANNELS; channel++) {
1314 cp = &s3c2410_chans[channel];
1315
1316 memset(cp, 0, sizeof(struct s3c2410_dma_chan));
1317
1318 /* dma channel irqs are in order.. */
1319 cp->number = channel;
1320 cp->irq = channel + IRQ_DMA0;
1321 cp->regs = dma_base + (channel*0x40);
1322
1323 /* point current stats somewhere */
1324 cp->stats = &cp->stats_store;
1325 cp->stats_store.timeout_shortest = LONG_MAX;
1326
1327 /* basic channel configuration */
1328
1329 cp->load_timeout = 1<<18;
1330
1331 /* register system device */
1332
1333 cp->dev.cls = &dma_sysclass;
1334 cp->dev.id = channel;
1335 ret = sysdev_register(&cp->dev);
1336
1337 printk("DMA channel %d at %p, irq %d\n",
1338 cp->number, cp->regs, cp->irq);
1339 }
1340
1341 return 0;
1342
1343 err:
1344 kmem_cache_destroy(dma_kmem);
1345 iounmap(dma_base);
1346 dma_base = NULL;
1347 return ret;
1348}
1349
1350core_initcall(s3c2410_init_dma);
1351
1352static inline int is_channel_valid(unsigned int channel)
1353{
1354 return (channel & DMA_CH_VALID);
1355}
1356
1357/* s3c2410_dma_map_channel()
1358 *
1359 * turn the virtual channel number into a real, and un-used hardware
1360 * channel.
1361 *
1362 * currently this code uses first-free channel from the specified harware
1363 * map, not taking into account anything that the board setup code may
1364 * have to say about the likely peripheral set to be in use.
1365*/
1366
1367struct s3c2410_dma_chan *s3c2410_dma_map_channel(int channel)
1368{
1369 struct s3c24xx_dma_map *ch_map;
1370 struct s3c2410_dma_chan *dmach;
1371 int ch;
1372
1373 if (dma_sel.map == NULL || channel > dma_sel.map_size)
1374 return NULL;
1375
1376 ch_map = dma_sel.map + channel;
1377
1378 for (ch = 0; ch < S3C2410_DMA_CHANNELS; ch++) {
1379 if (!is_channel_valid(ch_map->channels[ch]))
1380 continue;
1381
1382 if (s3c2410_chans[ch].in_use == 0) {
1383 printk("mapped channel %d to %d\n", channel, ch);
1384 break;
1385 }
1386 }
1387
1388 if (ch >= S3C2410_DMA_CHANNELS)
1389 return NULL;
1390
1391 /* update our channel mapping */
1392
1393 dmach = &s3c2410_chans[ch];
1394 dma_chan_map[channel] = dmach;
1395
1396 /* select the channel */
1397
1398 (dma_sel.select)(dmach, ch_map);
1399
1400 return dmach;
1401}
1402
1403static void s3c24xx_dma_show_ch(struct s3c24xx_dma_map *map, int ch)
1404{
1405 /* show the channel configuration */
1406
1407 printk("%2d: %20s, channels %c%c%c%c\n", ch, map->name,
1408 (is_channel_valid(map->channels[0]) ? '0' : '-'),
1409 (is_channel_valid(map->channels[1]) ? '1' : '-'),
1410 (is_channel_valid(map->channels[2]) ? '2' : '-'),
1411 (is_channel_valid(map->channels[3]) ? '3' : '-'));
1412}
1413
1414static int s3c24xx_dma_check_entry(struct s3c24xx_dma_map *map, int ch)
1415{
1416 if (1)
1417 s3c24xx_dma_show_ch(map, ch);
1418
1419 return 0;
1420}
1421
1422int __init s3c24xx_dma_init_map(struct s3c24xx_dma_selection *sel)
1423{
1424 struct s3c24xx_dma_map *nmap;
1425 size_t map_sz = sizeof(*nmap) * sel->map_size;
1426 int ptr;
1427
1428 nmap = kmalloc(map_sz, GFP_KERNEL);
1429 if (nmap == NULL)
1430 return -ENOMEM;
1431
1432 memcpy(nmap, sel->map, map_sz);
1433 memcpy(&dma_sel, sel, sizeof(*sel));
1434
1435 dma_sel.map = nmap;
1436
1437 for (ptr = 0; ptr < sel->map_size; ptr++)
1438 s3c24xx_dma_check_entry(nmap+ptr, ptr);
1439
1440 return 0;
1441}
generated by cgit v1.2.2 (git 2.25.0) at 2024-12-04 04:02:46 -0500