sound/soc/atmel/atmel-pcm-dma.c

   1 /*
   2  * atmel-pcm-dma.c  --  ALSA PCM DMA support for the Atmel SoC.
   3  *
   4  *  Copyright (C) 2012 Atmel
   5  *
   6  * Author: Bo Shen <voice.shen@atmel.com>
   7  *
   8  * Based on atmel-pcm by:
   9  * Sedji Gaouaou <sedji.gaouaou@atmel.com>
  10  * Copyright 2008 Atmel
  11  *
  12  * This program is free software; you can redistribute it and/or modify
  13  * it under the terms of the GNU General Public License as published by
  14  * the Free Software Foundation; either version 2 of the License, or
  15  * (at your option) any later version.
  16  *
  17  * This program is distributed in the hope that it will be useful,
  18  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  19  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  20  * GNU General Public License for more details.
  21  *
  22  * You should have received a copy of the GNU General Public License
  23  * along with this program; if not, write to the Free Software
  24  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  25  */
  26
  27 #include <linux/module.h>
  28 #include <linux/init.h>
  29 #include <linux/platform_device.h>
  30 #include <linux/slab.h>
  31 #include <linux/dma-mapping.h>
  32 #include <linux/dmaengine.h>
  33 #include <linux/atmel-ssc.h>
  34 #include <linux/platform_data/dma-atmel.h>
  35
  36 #include <sound/core.h>
  37 #include <sound/pcm.h>
  38 #include <sound/pcm_params.h>
  39 #include <sound/soc.h>
  40 #include <sound/dmaengine_pcm.h>
  41
  42 #include "atmel-pcm.h"
  43
  44 /*--------------------------------------------------------------------------*\
  45  * Hardware definition
  46 \*--------------------------------------------------------------------------*/
  47 static const struct snd_pcm_hardware atmel_pcm_dma_hardware = {
  48         .info                   = SNDRV_PCM_INFO_MMAP |
  49                                   SNDRV_PCM_INFO_MMAP_VALID |
  50                                   SNDRV_PCM_INFO_INTERLEAVED |
  51                                   SNDRV_PCM_INFO_RESUME |
  52                                   SNDRV_PCM_INFO_PAUSE,
  53         .formats                = SNDRV_PCM_FMTBIT_S16_LE,
  54         .period_bytes_min       = 256,          /* lighting DMA overhead */
  55         .period_bytes_max       = 2 * 0xffff,   /* if 2 bytes format */
  56         .periods_min            = 8,
  57         .periods_max            = 1024,         /* no limit */
  58         .buffer_bytes_max       = ATMEL_SSC_DMABUF_SIZE,
  59 };
  60
  61 /**
  62  * atmel_pcm_dma_irq: SSC interrupt handler for DMAENGINE enabled SSC
  63  *
  64  * We use DMAENGINE to send/receive data to/from SSC so this ISR is only to
  65  * check if any overrun occured.
  66  */
  67 static void atmel_pcm_dma_irq(u32 ssc_sr,
  68         struct snd_pcm_substream *substream)
  69 {
  70         struct snd_soc_pcm_runtime *rtd = substream->private_data;
  71         struct atmel_pcm_dma_params *prtd;
  72
  73         prtd = snd_soc_dai_get_dma_data(rtd->cpu_dai, substream);
  74
  75         if (ssc_sr & prtd->mask->ssc_error) {
  76                 if (snd_pcm_running(substream))
  77                         pr_warn("atmel-pcm: buffer %s on %s (SSC_SR=%#x)\n",
  78                                 substream->stream == SNDRV_PCM_STREAM_PLAYBACK
  79                                 ? "underrun" : "overrun", prtd->name,
  80                                 ssc_sr);
  81
  82                 /* stop RX and capture: will be enabled again at restart */
  83                 ssc_writex(prtd->ssc->regs, SSC_CR, prtd->mask->ssc_disable);
  84                 snd_pcm_stop(substream, SNDRV_PCM_STATE_XRUN);
  85
  86                 /* now drain RHR and read status to remove xrun condition */
  87                 ssc_readx(prtd->ssc->regs, SSC_RHR);
  88                 ssc_readx(prtd->ssc->regs, SSC_SR);
  89         }
  90 }
  91
  92 /*--------------------------------------------------------------------------*\
  93  * DMAENGINE operations
  94 \*--------------------------------------------------------------------------*/
  95 static bool filter(struct dma_chan *chan, void *slave)
  96 {
  97         struct at_dma_slave *sl = slave;
  98
  99         if (sl->dma_dev == chan->device->dev) {
 100                 chan->private = sl;
 101                 return true;
 102         } else {
 103                 return false;
 104         }
 105 }
 106
 107 static int atmel_pcm_configure_dma(struct snd_pcm_substream *substream,
 108         struct snd_pcm_hw_params *params, struct atmel_pcm_dma_params *prtd)
 109 {
 110         struct ssc_device *ssc;
 111         struct dma_chan *dma_chan;
 112         struct dma_slave_config slave_config;
 113         int ret;
 114
 115         ssc = prtd->ssc;
 116
 117         ret = snd_hwparams_to_dma_slave_config(substream, params,
 118                         &slave_config);
 119         if (ret) {
 120                 pr_err("atmel-pcm: hwparams to dma slave configure failed\n");
 121                 return ret;
 122         }
 123
 124         if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) {
 125                 slave_config.dst_addr = (dma_addr_t)ssc->phybase + SSC_THR;
 126                 slave_config.dst_maxburst = 1;
 127         } else {
 128                 slave_config.src_addr = (dma_addr_t)ssc->phybase + SSC_RHR;
 129                 slave_config.src_maxburst = 1;
 130         }
 131
 132         dma_chan = snd_dmaengine_pcm_get_chan(substream);
 133         if (dmaengine_slave_config(dma_chan, &slave_config)) {
 134                 pr_err("atmel-pcm: failed to configure dma channel\n");
 135                 ret = -EBUSY;
 136                 return ret;
 137         }
 138
 139         return 0;
 140 }
 141
 142 static int atmel_pcm_hw_params(struct snd_pcm_substream *substream,
 143         struct snd_pcm_hw_params *params)
 144 {
 145         struct snd_soc_pcm_runtime *rtd = substream->private_data;
 146         struct atmel_pcm_dma_params *prtd;
 147         struct ssc_device *ssc;
 148         struct at_dma_slave *sdata = NULL;
 149         int ret;
 150
 151         snd_pcm_set_runtime_buffer(substream, &substream->dma_buffer);
 152
 153         prtd = snd_soc_dai_get_dma_data(rtd->cpu_dai, substream);
 154         ssc = prtd->ssc;
 155         if (ssc->pdev)
 156                 sdata = ssc->pdev->dev.platform_data;
 157
 158         ret = snd_dmaengine_pcm_open_request_chan(substream, filter, sdata);
 159         if (ret) {
 160                 pr_err("atmel-pcm: dmaengine pcm open failed\n");
 161                 return -EINVAL;
 162         }
 163
 164         ret = atmel_pcm_configure_dma(substream, params, prtd);
 165         if (ret) {
 166                 pr_err("atmel-pcm: failed to configure dmai\n");
 167                 goto err;
 168         }
 169
 170         prtd->dma_intr_handler = atmel_pcm_dma_irq;
 171
 172         return 0;
 173 err:
 174         snd_dmaengine_pcm_close_release_chan(substream);
 175         return ret;
 176 }
 177
 178 static int atmel_pcm_dma_prepare(struct snd_pcm_substream *substream)
 179 {
 180         struct snd_soc_pcm_runtime *rtd = substream->private_data;
 181         struct atmel_pcm_dma_params *prtd;
 182
 183         prtd = snd_soc_dai_get_dma_data(rtd->cpu_dai, substream);
 184
 185         ssc_writex(prtd->ssc->regs, SSC_IER, prtd->mask->ssc_error);
 186         ssc_writex(prtd->ssc->regs, SSC_CR, prtd->mask->ssc_enable);
 187
 188         return 0;
 189 }
 190
 191 static int atmel_pcm_open(struct snd_pcm_substream *substream)
 192 {
 193         snd_soc_set_runtime_hwparams(substream, &atmel_pcm_dma_hardware);
 194
 195         return 0;
 196 }
 197
 198 static struct snd_pcm_ops atmel_pcm_ops = {
 199         .open           = atmel_pcm_open,
 200         .close          = snd_dmaengine_pcm_close_release_chan,
 201         .ioctl          = snd_pcm_lib_ioctl,
 202         .hw_params      = atmel_pcm_hw_params,
 203         .prepare        = atmel_pcm_dma_prepare,
 204         .trigger        = snd_dmaengine_pcm_trigger,
 205         .pointer        = snd_dmaengine_pcm_pointer_no_residue,
 206         .mmap           = atmel_pcm_mmap,
 207 };
 208
 209 static struct snd_soc_platform_driver atmel_soc_platform = {
 210         .ops            = &atmel_pcm_ops,
 211         .pcm_new        = atmel_pcm_new,
 212         .pcm_free       = atmel_pcm_free,
 213 };
 214
 215 int atmel_pcm_dma_platform_register(struct device *dev)
 216 {
 217         return snd_soc_register_platform(dev, &atmel_soc_platform);
 218 }
 219 EXPORT_SYMBOL(atmel_pcm_dma_platform_register);
 220
 221 void atmel_pcm_dma_platform_unregister(struct device *dev)
 222 {
 223         snd_soc_unregister_platform(dev);
 224 }
 225 EXPORT_SYMBOL(atmel_pcm_dma_platform_unregister);
 226
 227 MODULE_AUTHOR("Bo Shen <voice.shen@atmel.com>");
 228 MODULE_DESCRIPTION("Atmel DMA based PCM module");
 229 MODULE_LICENSE("GPL");