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_stream_lock(substream);
  85                 snd_pcm_stop(substream, SNDRV_PCM_STATE_XRUN);
  86                 snd_pcm_stream_unlock(substream);
  87
  88                 /* now drain RHR and read status to remove xrun condition */
  89                 ssc_readx(prtd->ssc->regs, SSC_RHR);
  90                 ssc_readx(prtd->ssc->regs, SSC_SR);
  91         }
  92 }
  93
  94 /*--------------------------------------------------------------------------*\
  95  * DMAENGINE operations
  96 \*--------------------------------------------------------------------------*/
  97 static bool filter(struct dma_chan *chan, void *slave)
  98 {
  99         struct at_dma_slave *sl = slave;
 100
 101         if (sl->dma_dev == chan->device->dev) {
 102                 chan->private = sl;
 103                 return true;
 104         } else {
 105                 return false;
 106         }
 107 }
 108
 109 static int atmel_pcm_configure_dma(struct snd_pcm_substream *substream,
 110         struct snd_pcm_hw_params *params, struct atmel_pcm_dma_params *prtd)
 111 {
 112         struct ssc_device *ssc;
 113         struct dma_chan *dma_chan;
 114         struct dma_slave_config slave_config;
 115         int ret;
 116
 117         ssc = prtd->ssc;
 118
 119         ret = snd_hwparams_to_dma_slave_config(substream, params,
 120                         &slave_config);
 121         if (ret) {
 122                 pr_err("atmel-pcm: hwparams to dma slave configure failed\n");
 123                 return ret;
 124         }
 125
 126         if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) {
 127                 slave_config.dst_addr = (dma_addr_t)ssc->phybase + SSC_THR;
 128                 slave_config.dst_maxburst = 1;
 129         } else {
 130                 slave_config.src_addr = (dma_addr_t)ssc->phybase + SSC_RHR;
 131                 slave_config.src_maxburst = 1;
 132         }
 133
 134         dma_chan = snd_dmaengine_pcm_get_chan(substream);
 135         if (dmaengine_slave_config(dma_chan, &slave_config)) {
 136                 pr_err("atmel-pcm: failed to configure dma channel\n");
 137                 ret = -EBUSY;
 138                 return ret;
 139         }
 140
 141         return 0;
 142 }
 143
 144 static int atmel_pcm_hw_params(struct snd_pcm_substream *substream,
 145         struct snd_pcm_hw_params *params)
 146 {
 147         struct snd_soc_pcm_runtime *rtd = substream->private_data;
 148         struct atmel_pcm_dma_params *prtd;
 149         struct ssc_device *ssc;
 150         struct at_dma_slave *sdata = NULL;
 151         int ret;
 152
 153         snd_pcm_set_runtime_buffer(substream, &substream->dma_buffer);
 154
 155         prtd = snd_soc_dai_get_dma_data(rtd->cpu_dai, substream);
 156         ssc = prtd->ssc;
 157         if (ssc->pdev)
 158                 sdata = ssc->pdev->dev.platform_data;
 159
 160         ret = snd_dmaengine_pcm_open_request_chan(substream, filter, sdata);
 161         if (ret) {
 162                 pr_err("atmel-pcm: dmaengine pcm open failed\n");
 163                 return -EINVAL;
 164         }
 165
 166         ret = atmel_pcm_configure_dma(substream, params, prtd);
 167         if (ret) {
 168                 pr_err("atmel-pcm: failed to configure dmai\n");
 169                 goto err;
 170         }
 171
 172         prtd->dma_intr_handler = atmel_pcm_dma_irq;
 173
 174         return 0;
 175 err:
 176         snd_dmaengine_pcm_close_release_chan(substream);
 177         return ret;
 178 }
 179
 180 static int atmel_pcm_dma_prepare(struct snd_pcm_substream *substream)
 181 {
 182         struct snd_soc_pcm_runtime *rtd = substream->private_data;
 183         struct atmel_pcm_dma_params *prtd;
 184
 185         prtd = snd_soc_dai_get_dma_data(rtd->cpu_dai, substream);
 186
 187         ssc_writex(prtd->ssc->regs, SSC_IER, prtd->mask->ssc_error);
 188         ssc_writex(prtd->ssc->regs, SSC_CR, prtd->mask->ssc_enable);
 189
 190         return 0;
 191 }
 192
 193 static int atmel_pcm_open(struct snd_pcm_substream *substream)
 194 {
 195         snd_soc_set_runtime_hwparams(substream, &atmel_pcm_dma_hardware);
 196
 197         return 0;
 198 }
 199
 200 static struct snd_pcm_ops atmel_pcm_ops = {
 201         .open           = atmel_pcm_open,
 202         .close          = snd_dmaengine_pcm_close_release_chan,
 203         .ioctl          = snd_pcm_lib_ioctl,
 204         .hw_params      = atmel_pcm_hw_params,
 205         .prepare        = atmel_pcm_dma_prepare,
 206         .trigger        = snd_dmaengine_pcm_trigger,
 207         .pointer        = snd_dmaengine_pcm_pointer_no_residue,
 208         .mmap           = atmel_pcm_mmap,
 209 };
 210
 211 static struct snd_soc_platform_driver atmel_soc_platform = {
 212         .ops            = &atmel_pcm_ops,
 213         .pcm_new        = atmel_pcm_new,
 214         .pcm_free       = atmel_pcm_free,
 215 };
 216
 217 int atmel_pcm_dma_platform_register(struct device *dev)
 218 {
 219         return snd_soc_register_platform(dev, &atmel_soc_platform);
 220 }
 221 EXPORT_SYMBOL(atmel_pcm_dma_platform_register);
 222
 223 void atmel_pcm_dma_platform_unregister(struct device *dev)
 224 {
 225         snd_soc_unregister_platform(dev);
 226 }
 227 EXPORT_SYMBOL(atmel_pcm_dma_platform_unregister);
 228
 229 MODULE_AUTHOR("Bo Shen <voice.shen@atmel.com>");
 230 MODULE_DESCRIPTION("Atmel DMA based PCM module");
 231 MODULE_LICENSE("GPL");