2 * s3c-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 s3c_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,
56 struct s3c24xx_runtime_data {
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 s3c_dma_enqueue(struct snd_pcm_substream *substream)
75 struct s3c24xx_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(KERN_DEBUG "%s: corrected dma len %ld\n",
101 ret = s3c2410_dma_enqueue(prtd->params->channel,
102 substream, pos, len);
106 pos += prtd->dma_period;
107 if (pos >= prtd->dma_end)
108 pos = prtd->dma_start;
116 static void s3c24xx_audio_buffdone(struct s3c2410_dma_chan *channel,
117 void *dev_id, int size,
118 enum s3c2410_dma_buffresult result)
120 struct snd_pcm_substream *substream = dev_id;
121 struct s3c24xx_runtime_data *prtd;
123 pr_debug("Entered %s\n", __func__);
125 if (result == S3C2410_RES_ABORT || result == S3C2410_RES_ERR)
128 prtd = substream->runtime->private_data;
131 snd_pcm_period_elapsed(substream);
133 spin_lock(&prtd->lock);
134 if (prtd->state & ST_RUNNING && !s3c_dma_has_circular()) {
136 s3c_dma_enqueue(substream);
139 spin_unlock(&prtd->lock);
142 static int s3c_dma_hw_params(struct snd_pcm_substream *substream,
143 struct snd_pcm_hw_params *params)
145 struct snd_pcm_runtime *runtime = substream->runtime;
146 struct s3c24xx_runtime_data *prtd = runtime->private_data;
147 struct snd_soc_pcm_runtime *rtd = substream->private_data;
148 struct s3c_dma_params *dma = rtd->dai->cpu_dai->dma_data;
149 unsigned long totbytes = params_buffer_bytes(params);
152 pr_debug("Entered %s\n", __func__);
154 /* return if this is a bufferless transfer e.g.
155 * codec <--> BT codec or GSM modem -- lg FIXME */
159 /* this may get called several times by oss emulation
160 * with different params -HW */
161 if (prtd->params == NULL) {
165 pr_debug("params %p, client %p, channel %d\n", prtd->params,
166 prtd->params->client, prtd->params->channel);
168 ret = s3c2410_dma_request(prtd->params->channel,
169 prtd->params->client, NULL);
172 printk(KERN_ERR "failed to get dma channel\n");
176 /* use the circular buffering if we have it available. */
177 if (s3c_dma_has_circular())
178 s3c2410_dma_setflags(prtd->params->channel,
179 S3C2410_DMAF_CIRCULAR);
182 s3c2410_dma_set_buffdone_fn(prtd->params->channel,
183 s3c24xx_audio_buffdone);
185 snd_pcm_set_runtime_buffer(substream, &substream->dma_buffer);
187 runtime->dma_bytes = totbytes;
189 spin_lock_irq(&prtd->lock);
190 prtd->dma_loaded = 0;
191 prtd->dma_limit = runtime->hw.periods_min;
192 prtd->dma_period = params_period_bytes(params);
193 prtd->dma_start = runtime->dma_addr;
194 prtd->dma_pos = prtd->dma_start;
195 prtd->dma_end = prtd->dma_start + totbytes;
196 spin_unlock_irq(&prtd->lock);
201 static int s3c_dma_hw_free(struct snd_pcm_substream *substream)
203 struct s3c24xx_runtime_data *prtd = substream->runtime->private_data;
205 pr_debug("Entered %s\n", __func__);
207 /* TODO - do we need to ensure DMA flushed */
208 snd_pcm_set_runtime_buffer(substream, NULL);
211 s3c2410_dma_free(prtd->params->channel, prtd->params->client);
218 static int s3c_dma_prepare(struct snd_pcm_substream *substream)
220 struct s3c24xx_runtime_data *prtd = substream->runtime->private_data;
223 pr_debug("Entered %s\n", __func__);
225 /* return if this is a bufferless transfer e.g.
226 * codec <--> BT codec or GSM modem -- lg FIXME */
230 /* channel needs configuring for mem=>device, increment memory addr,
231 * sync to pclk, half-word transfers to the IIS-FIFO. */
232 if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) {
233 s3c2410_dma_devconfig(prtd->params->channel,
235 prtd->params->dma_addr);
237 s3c2410_dma_devconfig(prtd->params->channel,
239 prtd->params->dma_addr);
242 s3c2410_dma_config(prtd->params->channel,
243 prtd->params->dma_size);
245 /* flush the DMA channel */
246 s3c2410_dma_ctrl(prtd->params->channel, S3C2410_DMAOP_FLUSH);
247 prtd->dma_loaded = 0;
248 prtd->dma_pos = prtd->dma_start;
250 /* enqueue dma buffers */
251 s3c_dma_enqueue(substream);
256 static int s3c_dma_trigger(struct snd_pcm_substream *substream, int cmd)
258 struct s3c24xx_runtime_data *prtd = substream->runtime->private_data;
261 pr_debug("Entered %s\n", __func__);
263 spin_lock(&prtd->lock);
266 case SNDRV_PCM_TRIGGER_START:
267 case SNDRV_PCM_TRIGGER_RESUME:
268 case SNDRV_PCM_TRIGGER_PAUSE_RELEASE:
269 prtd->state |= ST_RUNNING;
270 s3c2410_dma_ctrl(prtd->params->channel, S3C2410_DMAOP_START);
273 case SNDRV_PCM_TRIGGER_STOP:
274 case SNDRV_PCM_TRIGGER_SUSPEND:
275 case SNDRV_PCM_TRIGGER_PAUSE_PUSH:
276 prtd->state &= ~ST_RUNNING;
277 s3c2410_dma_ctrl(prtd->params->channel, S3C2410_DMAOP_STOP);
285 spin_unlock(&prtd->lock);
290 static snd_pcm_uframes_t
291 s3c_dma_pointer(struct snd_pcm_substream *substream)
293 struct snd_pcm_runtime *runtime = substream->runtime;
294 struct s3c24xx_runtime_data *prtd = runtime->private_data;
298 pr_debug("Entered %s\n", __func__);
300 spin_lock(&prtd->lock);
301 s3c2410_dma_getposition(prtd->params->channel, &src, &dst);
303 if (substream->stream == SNDRV_PCM_STREAM_CAPTURE)
304 res = dst - prtd->dma_start;
306 res = src - prtd->dma_start;
308 spin_unlock(&prtd->lock);
310 pr_debug("Pointer %x %x\n", src, dst);
312 /* we seem to be getting the odd error from the pcm library due
313 * to out-of-bounds pointers. this is maybe due to the dma engine
314 * not having loaded the new values for the channel before being
315 * callled... (todo - fix )
318 if (res >= snd_pcm_lib_buffer_bytes(substream)) {
319 if (res == snd_pcm_lib_buffer_bytes(substream))
323 return bytes_to_frames(substream->runtime, res);
326 static int s3c_dma_open(struct snd_pcm_substream *substream)
328 struct snd_pcm_runtime *runtime = substream->runtime;
329 struct s3c24xx_runtime_data *prtd;
331 pr_debug("Entered %s\n", __func__);
333 snd_pcm_hw_constraint_integer(runtime, SNDRV_PCM_HW_PARAM_PERIODS);
334 snd_soc_set_runtime_hwparams(substream, &s3c_dma_hardware);
336 prtd = kzalloc(sizeof(struct s3c24xx_runtime_data), GFP_KERNEL);
340 spin_lock_init(&prtd->lock);
342 runtime->private_data = prtd;
346 static int s3c_dma_close(struct snd_pcm_substream *substream)
348 struct snd_pcm_runtime *runtime = substream->runtime;
349 struct s3c24xx_runtime_data *prtd = runtime->private_data;
351 pr_debug("Entered %s\n", __func__);
354 pr_debug("s3c_dma_close called with prtd == NULL\n");
361 static int s3c_dma_mmap(struct snd_pcm_substream *substream,
362 struct vm_area_struct *vma)
364 struct snd_pcm_runtime *runtime = substream->runtime;
366 pr_debug("Entered %s\n", __func__);
368 return dma_mmap_writecombine(substream->pcm->card->dev, vma,
374 static struct snd_pcm_ops s3c_dma_ops = {
375 .open = s3c_dma_open,
376 .close = s3c_dma_close,
377 .ioctl = snd_pcm_lib_ioctl,
378 .hw_params = s3c_dma_hw_params,
379 .hw_free = s3c_dma_hw_free,
380 .prepare = s3c_dma_prepare,
381 .trigger = s3c_dma_trigger,
382 .pointer = s3c_dma_pointer,
383 .mmap = s3c_dma_mmap,
386 static int s3c_preallocate_dma_buffer(struct snd_pcm *pcm, int stream)
388 struct snd_pcm_substream *substream = pcm->streams[stream].substream;
389 struct snd_dma_buffer *buf = &substream->dma_buffer;
390 size_t size = s3c_dma_hardware.buffer_bytes_max;
392 pr_debug("Entered %s\n", __func__);
394 buf->dev.type = SNDRV_DMA_TYPE_DEV;
395 buf->dev.dev = pcm->card->dev;
396 buf->private_data = NULL;
397 buf->area = dma_alloc_writecombine(pcm->card->dev, size,
398 &buf->addr, GFP_KERNEL);
405 static void s3c_dma_free_dma_buffers(struct snd_pcm *pcm)
407 struct snd_pcm_substream *substream;
408 struct snd_dma_buffer *buf;
411 pr_debug("Entered %s\n", __func__);
413 for (stream = 0; stream < 2; stream++) {
414 substream = pcm->streams[stream].substream;
418 buf = &substream->dma_buffer;
422 dma_free_writecombine(pcm->card->dev, buf->bytes,
423 buf->area, buf->addr);
428 static u64 s3c_dma_mask = DMA_BIT_MASK(32);
430 static int s3c_dma_new(struct snd_card *card,
431 struct snd_soc_dai *dai, struct snd_pcm *pcm)
435 pr_debug("Entered %s\n", __func__);
437 if (!card->dev->dma_mask)
438 card->dev->dma_mask = &s3c_dma_mask;
439 if (!card->dev->coherent_dma_mask)
440 card->dev->coherent_dma_mask = 0xffffffff;
442 if (dai->playback.channels_min) {
443 ret = s3c_preallocate_dma_buffer(pcm,
444 SNDRV_PCM_STREAM_PLAYBACK);
449 if (dai->capture.channels_min) {
450 ret = s3c_preallocate_dma_buffer(pcm,
451 SNDRV_PCM_STREAM_CAPTURE);
459 struct snd_soc_platform s3c24xx_soc_platform = {
460 .name = "s3c24xx-audio",
461 .pcm_ops = &s3c_dma_ops,
462 .pcm_new = s3c_dma_new,
463 .pcm_free = s3c_dma_free_dma_buffers,
465 EXPORT_SYMBOL_GPL(s3c24xx_soc_platform);
467 static int __init s3c24xx_soc_platform_init(void)
469 return snd_soc_register_platform(&s3c24xx_soc_platform);
471 module_init(s3c24xx_soc_platform_init);
473 static void __exit s3c24xx_soc_platform_exit(void)
475 snd_soc_unregister_platform(&s3c24xx_soc_platform);
477 module_exit(s3c24xx_soc_platform_exit);
479 MODULE_AUTHOR("Ben Dooks, <ben@simtec.co.uk>");
480 MODULE_DESCRIPTION("Samsung S3C Audio DMA module");
481 MODULE_LICENSE("GPL");