sound/soc/spear/spear_pcm.c

   1 /*
   2  * ALSA PCM interface for ST SPEAr Processors
   3  *
   4  * sound/soc/spear/spear_pcm.c
   5  *
   6  * Copyright (C) 2012 ST Microelectronics
   7  * Rajeev Kumar<rajeev-dlh.kumar@st.com>
   8  *
   9  * This file is licensed under the terms of the GNU General Public
  10  * License version 2. This program is licensed "as is" without any
  11  * warranty of any kind, whether express or implied.
  12  */
  13
  14 #include <linux/module.h>
  15 #include <linux/dmaengine.h>
  16 #include <linux/platform_device.h>
  17 #include <sound/dmaengine_pcm.h>
  18 #include <sound/pcm.h>
  19 #include <sound/soc.h>
  20 #include <sound/spear_dma.h>
  21
  22 static const struct snd_pcm_hardware spear_pcm_hardware = {
  23         .info = (SNDRV_PCM_INFO_INTERLEAVED | SNDRV_PCM_INFO_BLOCK_TRANSFER |
  24                  SNDRV_PCM_INFO_MMAP | SNDRV_PCM_INFO_MMAP_VALID |
  25                  SNDRV_PCM_INFO_PAUSE | SNDRV_PCM_INFO_RESUME),
  26         .buffer_bytes_max = 16 * 1024, /* max buffer size */
  27         .period_bytes_min = 2 * 1024, /* 1 msec data minimum period size */
  28         .period_bytes_max = 2 * 1024, /* maximum period size */
  29         .periods_min = 1, /* min # periods */
  30         .periods_max = 8, /* max # of periods */
  31         .fifo_size = 0, /* fifo size in bytes */
  32 };
  33
  34 static struct dma_chan *spear_pcm_request_chan(struct snd_soc_pcm_runtime *rtd,
  35         struct snd_pcm_substream *substream)
  36 {
  37         struct spear_dma_data *dma_data;
  38
  39         dma_data = snd_soc_dai_get_dma_data(rtd->cpu_dai, substream);
  40
  41         return snd_dmaengine_pcm_request_channel(dma_data->filter, dma_data);
  42 }
  43
  44 static const struct snd_dmaengine_pcm_config spear_dmaengine_pcm_config = {
  45         .pcm_hardware = &spear_pcm_hardware,
  46         .compat_request_channel = spear_pcm_request_chan,
  47         .prealloc_buffer_size = 16 * 1024,
  48 };
  49
  50 static int spear_soc_platform_probe(struct platform_device *pdev)
  51 {
  52         return snd_dmaengine_pcm_register(&pdev->dev,
  53                 &spear_dmaengine_pcm_config,
  54                 SND_DMAENGINE_PCM_FLAG_NO_DT |
  55                 SND_DMAENGINE_PCM_FLAG_COMPAT);
  56 }
  57
  58 static int spear_soc_platform_remove(struct platform_device *pdev)
  59 {
  60         snd_dmaengine_pcm_unregister(&pdev->dev);
  61         return 0;
  62 }
  63
  64 static struct platform_driver spear_pcm_driver = {
  65         .driver = {
  66                 .name = "spear-pcm-audio",
  67                 .owner = THIS_MODULE,
  68         },
  69
  70         .probe = spear_soc_platform_probe,
  71         .remove = spear_soc_platform_remove,
  72 };
  73
  74 module_platform_driver(spear_pcm_driver);
  75
  76 MODULE_AUTHOR("Rajeev Kumar <rajeev-dlh.kumar@st.com>");
  77 MODULE_DESCRIPTION("SPEAr PCM DMA module");
  78 MODULE_LICENSE("GPL");
  79 MODULE_ALIAS("platform:spear-pcm-audio");