2 * omap-pcm.c -- ALSA PCM interface for the OMAP SoC
4 * Copyright (C) 2008 Nokia Corporation
6 * Contact: Jarkko Nikula <jarkko.nikula@nokia.com>
8 * This program is free software; you can redistribute it and/or
9 * modify it under the terms of the GNU General Public License
10 * version 2 as published by the Free Software Foundation.
12 * This program is distributed in the hope that it will be useful, but
13 * WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15 * General Public License for more details.
17 * You should have received a copy of the GNU General Public License
18 * along with this program; if not, write to the Free Software
19 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
24 #include <linux/dma-mapping.h>
25 #include <sound/core.h>
26 #include <sound/pcm.h>
27 #include <sound/pcm_params.h>
28 #include <sound/soc.h>
30 #include <asm/arch/dma.h>
33 static const struct snd_pcm_hardware omap_pcm_hardware = {
34 .info = SNDRV_PCM_INFO_MMAP |
35 SNDRV_PCM_INFO_MMAP_VALID |
36 SNDRV_PCM_INFO_INTERLEAVED |
37 SNDRV_PCM_INFO_PAUSE |
38 SNDRV_PCM_INFO_RESUME,
39 .formats = SNDRV_PCM_FMTBIT_S16_LE,
40 .period_bytes_min = 32,
41 .period_bytes_max = 64 * 1024,
44 .buffer_bytes_max = 128 * 1024,
47 struct omap_runtime_data {
49 struct omap_pcm_dma_data *dma_data;
54 static void omap_pcm_dma_irq(int ch, u16 stat, void *data)
56 struct snd_pcm_substream *substream = data;
57 struct snd_pcm_runtime *runtime = substream->runtime;
58 struct omap_runtime_data *prtd = runtime->private_data;
61 if (cpu_is_omap1510()) {
63 * OMAP1510 doesn't support DMA chaining so have to restart
64 * the transfer after all periods are transferred
66 spin_lock_irqsave(&prtd->lock, flags);
67 if (prtd->period_index >= 0) {
68 if (++prtd->period_index == runtime->periods) {
69 prtd->period_index = 0;
70 omap_start_dma(prtd->dma_ch);
73 spin_unlock_irqrestore(&prtd->lock, flags);
76 snd_pcm_period_elapsed(substream);
79 /* this may get called several times by oss emulation */
80 static int omap_pcm_hw_params(struct snd_pcm_substream *substream,
81 struct snd_pcm_hw_params *params)
83 struct snd_pcm_runtime *runtime = substream->runtime;
84 struct snd_soc_pcm_runtime *rtd = substream->private_data;
85 struct omap_runtime_data *prtd = runtime->private_data;
86 struct omap_pcm_dma_data *dma_data = rtd->dai->cpu_dai->dma_data;
92 snd_pcm_set_runtime_buffer(substream, &substream->dma_buffer);
93 runtime->dma_bytes = params_buffer_bytes(params);
97 prtd->dma_data = dma_data;
98 err = omap_request_dma(dma_data->dma_req, dma_data->name,
99 omap_pcm_dma_irq, substream, &prtd->dma_ch);
100 if (!cpu_is_omap1510()) {
102 * Link channel with itself so DMA doesn't need any
103 * reprogramming while looping the buffer
105 omap_dma_link_lch(prtd->dma_ch, prtd->dma_ch);
111 static int omap_pcm_hw_free(struct snd_pcm_substream *substream)
113 struct snd_pcm_runtime *runtime = substream->runtime;
114 struct omap_runtime_data *prtd = runtime->private_data;
116 if (prtd->dma_data == NULL)
119 if (!cpu_is_omap1510())
120 omap_dma_unlink_lch(prtd->dma_ch, prtd->dma_ch);
121 omap_free_dma(prtd->dma_ch);
122 prtd->dma_data = NULL;
124 snd_pcm_set_runtime_buffer(substream, NULL);
129 static int omap_pcm_prepare(struct snd_pcm_substream *substream)
131 struct snd_pcm_runtime *runtime = substream->runtime;
132 struct omap_runtime_data *prtd = runtime->private_data;
133 struct omap_pcm_dma_data *dma_data = prtd->dma_data;
134 struct omap_dma_channel_params dma_params;
136 memset(&dma_params, 0, sizeof(dma_params));
138 * Note: Regardless of interface data formats supported by OMAP McBSP
139 * or EAC blocks, internal representation is always fixed 16-bit/sample
141 dma_params.data_type = OMAP_DMA_DATA_TYPE_S16;
142 dma_params.trigger = dma_data->dma_req;
143 dma_params.sync_mode = OMAP_DMA_SYNC_ELEMENT;
144 if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) {
145 dma_params.src_amode = OMAP_DMA_AMODE_POST_INC;
146 dma_params.dst_amode = OMAP_DMA_AMODE_CONSTANT;
147 dma_params.src_or_dst_synch = OMAP_DMA_DST_SYNC;
148 dma_params.src_start = runtime->dma_addr;
149 dma_params.dst_start = dma_data->port_addr;
151 dma_params.src_amode = OMAP_DMA_AMODE_CONSTANT;
152 dma_params.dst_amode = OMAP_DMA_AMODE_POST_INC;
153 dma_params.src_or_dst_synch = OMAP_DMA_SRC_SYNC;
154 dma_params.src_start = dma_data->port_addr;
155 dma_params.dst_start = runtime->dma_addr;
158 * Set DMA transfer frame size equal to ALSA period size and frame
159 * count as no. of ALSA periods. Then with DMA frame interrupt enabled,
160 * we can transfer the whole ALSA buffer with single DMA transfer but
161 * still can get an interrupt at each period bounary
163 dma_params.elem_count = snd_pcm_lib_period_bytes(substream) / 2;
164 dma_params.frame_count = runtime->periods;
165 omap_set_dma_params(prtd->dma_ch, &dma_params);
167 omap_enable_dma_irq(prtd->dma_ch, OMAP_DMA_FRAME_IRQ);
172 static int omap_pcm_trigger(struct snd_pcm_substream *substream, int cmd)
174 struct snd_pcm_runtime *runtime = substream->runtime;
175 struct omap_runtime_data *prtd = runtime->private_data;
178 spin_lock_irq(&prtd->lock);
180 case SNDRV_PCM_TRIGGER_START:
181 case SNDRV_PCM_TRIGGER_RESUME:
182 case SNDRV_PCM_TRIGGER_PAUSE_RELEASE:
183 prtd->period_index = 0;
184 omap_start_dma(prtd->dma_ch);
187 case SNDRV_PCM_TRIGGER_STOP:
188 case SNDRV_PCM_TRIGGER_SUSPEND:
189 case SNDRV_PCM_TRIGGER_PAUSE_PUSH:
190 prtd->period_index = -1;
191 omap_stop_dma(prtd->dma_ch);
196 spin_unlock_irq(&prtd->lock);
201 static snd_pcm_uframes_t omap_pcm_pointer(struct snd_pcm_substream *substream)
203 struct snd_pcm_runtime *runtime = substream->runtime;
204 struct omap_runtime_data *prtd = runtime->private_data;
206 snd_pcm_uframes_t offset;
208 if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
209 ptr = omap_get_dma_src_pos(prtd->dma_ch);
211 ptr = omap_get_dma_dst_pos(prtd->dma_ch);
213 offset = bytes_to_frames(runtime, ptr - runtime->dma_addr);
214 if (offset >= runtime->buffer_size)
220 static int omap_pcm_open(struct snd_pcm_substream *substream)
222 struct snd_pcm_runtime *runtime = substream->runtime;
223 struct omap_runtime_data *prtd;
226 snd_soc_set_runtime_hwparams(substream, &omap_pcm_hardware);
228 /* Ensure that buffer size is a multiple of period size */
229 ret = snd_pcm_hw_constraint_integer(runtime,
230 SNDRV_PCM_HW_PARAM_PERIODS);
234 prtd = kzalloc(sizeof(prtd), GFP_KERNEL);
239 spin_lock_init(&prtd->lock);
240 runtime->private_data = prtd;
246 static int omap_pcm_close(struct snd_pcm_substream *substream)
248 struct snd_pcm_runtime *runtime = substream->runtime;
250 kfree(runtime->private_data);
254 static int omap_pcm_mmap(struct snd_pcm_substream *substream,
255 struct vm_area_struct *vma)
257 struct snd_pcm_runtime *runtime = substream->runtime;
259 return dma_mmap_writecombine(substream->pcm->card->dev, vma,
265 struct snd_pcm_ops omap_pcm_ops = {
266 .open = omap_pcm_open,
267 .close = omap_pcm_close,
268 .ioctl = snd_pcm_lib_ioctl,
269 .hw_params = omap_pcm_hw_params,
270 .hw_free = omap_pcm_hw_free,
271 .prepare = omap_pcm_prepare,
272 .trigger = omap_pcm_trigger,
273 .pointer = omap_pcm_pointer,
274 .mmap = omap_pcm_mmap,
277 static u64 omap_pcm_dmamask = DMA_BIT_MASK(32);
279 static int omap_pcm_preallocate_dma_buffer(struct snd_pcm *pcm,
282 struct snd_pcm_substream *substream = pcm->streams[stream].substream;
283 struct snd_dma_buffer *buf = &substream->dma_buffer;
284 size_t size = omap_pcm_hardware.buffer_bytes_max;
286 buf->dev.type = SNDRV_DMA_TYPE_DEV;
287 buf->dev.dev = pcm->card->dev;
288 buf->private_data = NULL;
289 buf->area = dma_alloc_writecombine(pcm->card->dev, size,
290 &buf->addr, GFP_KERNEL);
298 static void omap_pcm_free_dma_buffers(struct snd_pcm *pcm)
300 struct snd_pcm_substream *substream;
301 struct snd_dma_buffer *buf;
304 for (stream = 0; stream < 2; stream++) {
305 substream = pcm->streams[stream].substream;
309 buf = &substream->dma_buffer;
313 dma_free_writecombine(pcm->card->dev, buf->bytes,
314 buf->area, buf->addr);
319 int omap_pcm_new(struct snd_card *card, struct snd_soc_dai *dai,
324 if (!card->dev->dma_mask)
325 card->dev->dma_mask = &omap_pcm_dmamask;
326 if (!card->dev->coherent_dma_mask)
327 card->dev->coherent_dma_mask = DMA_32BIT_MASK;
329 if (dai->playback.channels_min) {
330 ret = omap_pcm_preallocate_dma_buffer(pcm,
331 SNDRV_PCM_STREAM_PLAYBACK);
336 if (dai->capture.channels_min) {
337 ret = omap_pcm_preallocate_dma_buffer(pcm,
338 SNDRV_PCM_STREAM_CAPTURE);
347 struct snd_soc_platform omap_soc_platform = {
348 .name = "omap-pcm-audio",
349 .pcm_ops = &omap_pcm_ops,
350 .pcm_new = omap_pcm_new,
351 .pcm_free = omap_pcm_free_dma_buffers,
353 EXPORT_SYMBOL_GPL(omap_soc_platform);
355 MODULE_AUTHOR("Jarkko Nikula <jarkko.nikula@nokia.com>");
356 MODULE_DESCRIPTION("OMAP PCM DMA module");
357 MODULE_LICENSE("GPL");