2 * dma.c -- ALSA Soc Audio Layer
4 * (c) 2006 Wolfson Microelectronics PLC.
5 * Graeme Gregory graeme.gregory@wolfsonmicro.com or linux@wolfsonmicro.com
7 * Copyright 2004-2005 Simtec Electronics
8 * http://armlinux.simtec.co.uk/
9 * Ben Dooks <ben@simtec.co.uk>
11 * This program is free software; you can redistribute it and/or modify it
12 * under the terms of the GNU General Public License as published by the
13 * Free Software Foundation; either version 2 of the License, or (at your
14 * option) any later version.
17 #include <linux/module.h>
18 #include <linux/init.h>
20 #include <linux/platform_device.h>
21 #include <linux/slab.h>
22 #include <linux/dma-mapping.h>
24 #include <sound/core.h>
25 #include <sound/pcm.h>
26 #include <sound/pcm_params.h>
27 #include <sound/soc.h>
30 #include <mach/hardware.h>
35 static const struct snd_pcm_hardware dma_hardware = {
36 .info = SNDRV_PCM_INFO_INTERLEAVED |
37 SNDRV_PCM_INFO_BLOCK_TRANSFER |
39 SNDRV_PCM_INFO_MMAP_VALID |
40 SNDRV_PCM_INFO_PAUSE |
41 SNDRV_PCM_INFO_RESUME,
42 .formats = SNDRV_PCM_FMTBIT_S16_LE |
43 SNDRV_PCM_FMTBIT_U16_LE |
48 .buffer_bytes_max = 128*1024,
49 .period_bytes_min = PAGE_SIZE,
50 .period_bytes_max = PAGE_SIZE*2,
59 unsigned int dma_loaded;
60 unsigned int dma_limit;
61 unsigned int dma_period;
65 struct s3c_dma_params *params;
70 * place a dma buffer onto the queue for the dma system
73 static void dma_enqueue(struct snd_pcm_substream *substream)
75 struct runtime_data *prtd = substream->runtime->private_data;
76 dma_addr_t pos = prtd->dma_pos;
80 pr_debug("Entered %s\n", __func__);
82 if (s3c_dma_has_circular())
83 limit = (prtd->dma_end - prtd->dma_start) / prtd->dma_period;
85 limit = prtd->dma_limit;
87 pr_debug("%s: loaded %d, limit %d\n",
88 __func__, prtd->dma_loaded, limit);
90 while (prtd->dma_loaded < limit) {
91 unsigned long len = prtd->dma_period;
93 pr_debug("dma_loaded: %d\n", prtd->dma_loaded);
95 if ((pos + len) > prtd->dma_end) {
96 len = prtd->dma_end - pos;
97 pr_debug("%s: corrected dma len %ld\n", __func__, len);
100 ret = s3c2410_dma_enqueue(prtd->params->channel,
101 substream, pos, len);
105 pos += prtd->dma_period;
106 if (pos >= prtd->dma_end)
107 pos = prtd->dma_start;
115 static void audio_buffdone(struct s3c2410_dma_chan *channel,
116 void *dev_id, int size,
117 enum s3c2410_dma_buffresult result)
119 struct snd_pcm_substream *substream = dev_id;
120 struct runtime_data *prtd;
122 pr_debug("Entered %s\n", __func__);
124 if (result == S3C2410_RES_ABORT || result == S3C2410_RES_ERR)
127 prtd = substream->runtime->private_data;
130 snd_pcm_period_elapsed(substream);
132 spin_lock(&prtd->lock);
133 if (prtd->state & ST_RUNNING && !s3c_dma_has_circular()) {
135 dma_enqueue(substream);
138 spin_unlock(&prtd->lock);
141 static int dma_hw_params(struct snd_pcm_substream *substream,
142 struct snd_pcm_hw_params *params)
144 struct snd_pcm_runtime *runtime = substream->runtime;
145 struct runtime_data *prtd = runtime->private_data;
146 struct snd_soc_pcm_runtime *rtd = substream->private_data;
147 unsigned long totbytes = params_buffer_bytes(params);
148 struct s3c_dma_params *dma =
149 snd_soc_dai_get_dma_data(rtd->cpu_dai, substream);
153 pr_debug("Entered %s\n", __func__);
155 /* return if this is a bufferless transfer e.g.
156 * codec <--> BT codec or GSM modem -- lg FIXME */
160 /* this may get called several times by oss emulation
161 * with different params -HW */
162 if (prtd->params == NULL) {
166 pr_debug("params %p, client %p, channel %d\n", prtd->params,
167 prtd->params->client, prtd->params->channel);
169 ret = s3c2410_dma_request(prtd->params->channel,
170 prtd->params->client, NULL);
173 printk(KERN_ERR "failed to get dma channel\n");
177 /* use the circular buffering if we have it available. */
178 if (s3c_dma_has_circular())
179 s3c2410_dma_setflags(prtd->params->channel,
180 S3C2410_DMAF_CIRCULAR);
183 s3c2410_dma_set_buffdone_fn(prtd->params->channel,
186 snd_pcm_set_runtime_buffer(substream, &substream->dma_buffer);
188 runtime->dma_bytes = totbytes;
190 spin_lock_irq(&prtd->lock);
191 prtd->dma_loaded = 0;
192 prtd->dma_limit = runtime->hw.periods_min;
193 prtd->dma_period = params_period_bytes(params);
194 prtd->dma_start = runtime->dma_addr;
195 prtd->dma_pos = prtd->dma_start;
196 prtd->dma_end = prtd->dma_start + totbytes;
197 spin_unlock_irq(&prtd->lock);
202 static int dma_hw_free(struct snd_pcm_substream *substream)
204 struct runtime_data *prtd = substream->runtime->private_data;
206 pr_debug("Entered %s\n", __func__);
208 /* TODO - do we need to ensure DMA flushed */
209 snd_pcm_set_runtime_buffer(substream, NULL);
212 s3c2410_dma_free(prtd->params->channel, prtd->params->client);
219 static int dma_prepare(struct snd_pcm_substream *substream)
221 struct runtime_data *prtd = substream->runtime->private_data;
224 pr_debug("Entered %s\n", __func__);
226 /* return if this is a bufferless transfer e.g.
227 * codec <--> BT codec or GSM modem -- lg FIXME */
231 /* channel needs configuring for mem=>device, increment memory addr,
232 * sync to pclk, half-word transfers to the IIS-FIFO. */
233 if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) {
234 s3c2410_dma_devconfig(prtd->params->channel,
236 prtd->params->dma_addr);
238 s3c2410_dma_devconfig(prtd->params->channel,
240 prtd->params->dma_addr);
243 s3c2410_dma_config(prtd->params->channel,
244 prtd->params->dma_size);
246 /* flush the DMA channel */
247 s3c2410_dma_ctrl(prtd->params->channel, S3C2410_DMAOP_FLUSH);
248 prtd->dma_loaded = 0;
249 prtd->dma_pos = prtd->dma_start;
251 /* enqueue dma buffers */
252 dma_enqueue(substream);
257 static int dma_trigger(struct snd_pcm_substream *substream, int cmd)
259 struct runtime_data *prtd = substream->runtime->private_data;
262 pr_debug("Entered %s\n", __func__);
264 spin_lock(&prtd->lock);
267 case SNDRV_PCM_TRIGGER_START:
268 case SNDRV_PCM_TRIGGER_RESUME:
269 case SNDRV_PCM_TRIGGER_PAUSE_RELEASE:
270 prtd->state |= ST_RUNNING;
271 s3c2410_dma_ctrl(prtd->params->channel, S3C2410_DMAOP_START);
274 case SNDRV_PCM_TRIGGER_STOP:
275 case SNDRV_PCM_TRIGGER_SUSPEND:
276 case SNDRV_PCM_TRIGGER_PAUSE_PUSH:
277 prtd->state &= ~ST_RUNNING;
278 s3c2410_dma_ctrl(prtd->params->channel, S3C2410_DMAOP_STOP);
286 spin_unlock(&prtd->lock);
291 static snd_pcm_uframes_t
292 dma_pointer(struct snd_pcm_substream *substream)
294 struct snd_pcm_runtime *runtime = substream->runtime;
295 struct runtime_data *prtd = runtime->private_data;
299 pr_debug("Entered %s\n", __func__);
301 spin_lock(&prtd->lock);
302 s3c2410_dma_getposition(prtd->params->channel, &src, &dst);
304 if (substream->stream == SNDRV_PCM_STREAM_CAPTURE)
305 res = dst - prtd->dma_start;
307 res = src - prtd->dma_start;
309 spin_unlock(&prtd->lock);
311 pr_debug("Pointer %x %x\n", src, dst);
313 /* we seem to be getting the odd error from the pcm library due
314 * to out-of-bounds pointers. this is maybe due to the dma engine
315 * not having loaded the new values for the channel before being
316 * callled... (todo - fix )
319 if (res >= snd_pcm_lib_buffer_bytes(substream)) {
320 if (res == snd_pcm_lib_buffer_bytes(substream))
324 return bytes_to_frames(substream->runtime, res);
327 static int dma_open(struct snd_pcm_substream *substream)
329 struct snd_pcm_runtime *runtime = substream->runtime;
330 struct runtime_data *prtd;
332 pr_debug("Entered %s\n", __func__);
334 snd_pcm_hw_constraint_integer(runtime, SNDRV_PCM_HW_PARAM_PERIODS);
335 snd_soc_set_runtime_hwparams(substream, &dma_hardware);
337 prtd = kzalloc(sizeof(struct runtime_data), GFP_KERNEL);
341 spin_lock_init(&prtd->lock);
343 runtime->private_data = prtd;
347 static int dma_close(struct snd_pcm_substream *substream)
349 struct snd_pcm_runtime *runtime = substream->runtime;
350 struct runtime_data *prtd = runtime->private_data;
352 pr_debug("Entered %s\n", __func__);
355 pr_debug("dma_close called with prtd == NULL\n");
362 static int dma_mmap(struct snd_pcm_substream *substream,
363 struct vm_area_struct *vma)
365 struct snd_pcm_runtime *runtime = substream->runtime;
367 pr_debug("Entered %s\n", __func__);
369 return dma_mmap_writecombine(substream->pcm->card->dev, vma,
375 static struct snd_pcm_ops dma_ops = {
378 .ioctl = snd_pcm_lib_ioctl,
379 .hw_params = dma_hw_params,
380 .hw_free = dma_hw_free,
381 .prepare = dma_prepare,
382 .trigger = dma_trigger,
383 .pointer = dma_pointer,
387 static int preallocate_dma_buffer(struct snd_pcm *pcm, int stream)
389 struct snd_pcm_substream *substream = pcm->streams[stream].substream;
390 struct snd_dma_buffer *buf = &substream->dma_buffer;
391 size_t size = dma_hardware.buffer_bytes_max;
393 pr_debug("Entered %s\n", __func__);
395 buf->dev.type = SNDRV_DMA_TYPE_DEV;
396 buf->dev.dev = pcm->card->dev;
397 buf->private_data = NULL;
398 buf->area = dma_alloc_writecombine(pcm->card->dev, size,
399 &buf->addr, GFP_KERNEL);
406 static void dma_free_dma_buffers(struct snd_pcm *pcm)
408 struct snd_pcm_substream *substream;
409 struct snd_dma_buffer *buf;
412 pr_debug("Entered %s\n", __func__);
414 for (stream = 0; stream < 2; stream++) {
415 substream = pcm->streams[stream].substream;
419 buf = &substream->dma_buffer;
423 dma_free_writecombine(pcm->card->dev, buf->bytes,
424 buf->area, buf->addr);
429 static u64 dma_mask = DMA_BIT_MASK(32);
431 static int dma_new(struct snd_card *card,
432 struct snd_soc_dai *dai, struct snd_pcm *pcm)
436 pr_debug("Entered %s\n", __func__);
438 if (!card->dev->dma_mask)
439 card->dev->dma_mask = &dma_mask;
440 if (!card->dev->coherent_dma_mask)
441 card->dev->coherent_dma_mask = 0xffffffff;
443 if (dai->driver->playback.channels_min) {
444 ret = preallocate_dma_buffer(pcm,
445 SNDRV_PCM_STREAM_PLAYBACK);
450 if (dai->driver->capture.channels_min) {
451 ret = preallocate_dma_buffer(pcm,
452 SNDRV_PCM_STREAM_CAPTURE);
460 static struct snd_soc_platform_driver samsung_asoc_platform = {
463 .pcm_free = dma_free_dma_buffers,
466 static int __devinit samsung_asoc_platform_probe(struct platform_device *pdev)
468 return snd_soc_register_platform(&pdev->dev, &samsung_asoc_platform);
471 static int __devexit samsung_asoc_platform_remove(struct platform_device *pdev)
473 snd_soc_unregister_platform(&pdev->dev);
477 static struct platform_driver asoc_dma_driver = {
479 .name = "samsung-audio",
480 .owner = THIS_MODULE,
483 .probe = samsung_asoc_platform_probe,
484 .remove = __devexit_p(samsung_asoc_platform_remove),
487 static int __init samsung_asoc_init(void)
489 return platform_driver_register(&asoc_dma_driver);
491 module_init(samsung_asoc_init);
493 static void __exit samsung_asoc_exit(void)
495 platform_driver_unregister(&asoc_dma_driver);
497 module_exit(samsung_asoc_exit);
499 MODULE_AUTHOR("Ben Dooks, <ben@simtec.co.uk>");
500 MODULE_DESCRIPTION("Samsung ASoC DMA Driver");
501 MODULE_LICENSE("GPL");
502 MODULE_ALIAS("platform:samsung-audio");