sound/soc/dwc/designware_pcm.c

   1 /*
   2  * ALSA SoC Synopsys PIO PCM for I2S driver
   3  *
   4  * sound/soc/dwc/designware_pcm.c
   5  *
   6  * Copyright (C) 2016 Synopsys
   7  * Jose Abreu <joabreu@synopsys.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/io.h>
  15 #include <linux/rcupdate.h>
  16 #include <sound/pcm.h>
  17 #include <sound/pcm_params.h>
  18 #include "local.h"
  19
  20 #define BUFFER_BYTES_MAX        (3 * 2 * 8 * PERIOD_BYTES_MIN)
  21 #define PERIOD_BYTES_MIN        4096
  22 #define PERIODS_MIN             2
  23
  24 #define dw_pcm_tx_fn(sample_bits) \
  25 static unsigned int dw_pcm_tx_##sample_bits(struct dw_i2s_dev *dev, \
  26                 struct snd_pcm_runtime *runtime, unsigned int tx_ptr, \
  27                 bool *period_elapsed) \
  28 { \
  29         const u##sample_bits (*p)[2] = (void *)runtime->dma_area; \
  30         unsigned int period_pos = tx_ptr % runtime->period_size; \
  31         int i; \
  32 \
  33         for (i = 0; i < dev->fifo_th; i++) { \
  34                 iowrite32(p[tx_ptr][0], dev->i2s_base + LRBR_LTHR(0)); \
  35                 iowrite32(p[tx_ptr][1], dev->i2s_base + RRBR_RTHR(0)); \
  36                 period_pos++; \
  37                 if (++tx_ptr >= runtime->buffer_size) \
  38                         tx_ptr = 0; \
  39         } \
  40         *period_elapsed = period_pos >= runtime->period_size; \
  41         return tx_ptr; \
  42 }
  43
  44 dw_pcm_tx_fn(16);
  45 dw_pcm_tx_fn(32);
  46
  47 #undef dw_pcm_tx_fn
  48
  49 static const struct snd_pcm_hardware dw_pcm_hardware = {
  50         .info = SNDRV_PCM_INFO_INTERLEAVED |
  51                 SNDRV_PCM_INFO_MMAP |
  52                 SNDRV_PCM_INFO_MMAP_VALID |
  53                 SNDRV_PCM_INFO_BLOCK_TRANSFER,
  54         .rates = SNDRV_PCM_RATE_32000 |
  55                 SNDRV_PCM_RATE_44100 |
  56                 SNDRV_PCM_RATE_48000,
  57         .rate_min = 32000,
  58         .rate_max = 48000,
  59         .formats = SNDRV_PCM_FMTBIT_S16_LE |
  60                 SNDRV_PCM_FMTBIT_S32_LE,
  61         .channels_min = 2,
  62         .channels_max = 2,
  63         .buffer_bytes_max = BUFFER_BYTES_MAX,
  64         .period_bytes_min = PERIOD_BYTES_MIN,
  65         .period_bytes_max = BUFFER_BYTES_MAX / PERIODS_MIN,
  66         .periods_min = PERIODS_MIN,
  67         .periods_max = BUFFER_BYTES_MAX / PERIOD_BYTES_MIN,
  68         .fifo_size = 16,
  69 };
  70
  71 void dw_pcm_push_tx(struct dw_i2s_dev *dev)
  72 {
  73         struct snd_pcm_substream *tx_substream;
  74         bool tx_active, period_elapsed;
  75
  76         rcu_read_lock();
  77         tx_substream = rcu_dereference(dev->tx_substream);
  78         tx_active = tx_substream && snd_pcm_running(tx_substream);
  79         if (tx_active) {
  80                 unsigned int tx_ptr = READ_ONCE(dev->tx_ptr);
  81                 unsigned int new_tx_ptr = dev->tx_fn(dev, tx_substream->runtime,
  82                                 tx_ptr, &period_elapsed);
  83                 cmpxchg(&dev->tx_ptr, tx_ptr, new_tx_ptr);
  84
  85                 if (period_elapsed)
  86                         snd_pcm_period_elapsed(tx_substream);
  87         }
  88         rcu_read_unlock();
  89 }
  90 EXPORT_SYMBOL_GPL(dw_pcm_push_tx);
  91
  92 static int dw_pcm_open(struct snd_pcm_substream *substream)
  93 {
  94         struct snd_pcm_runtime *runtime = substream->runtime;
  95         struct snd_soc_pcm_runtime *rtd = substream->private_data;
  96         struct dw_i2s_dev *dev = snd_soc_dai_get_drvdata(rtd->cpu_dai);
  97
  98         snd_soc_set_runtime_hwparams(substream, &dw_pcm_hardware);
  99         snd_pcm_hw_constraint_integer(runtime, SNDRV_PCM_HW_PARAM_PERIODS);
 100         runtime->private_data = dev;
 101
 102         return 0;
 103 }
 104
 105 static int dw_pcm_close(struct snd_pcm_substream *substream)
 106 {
 107         synchronize_rcu();
 108         return 0;
 109 }
 110
 111 static int dw_pcm_hw_params(struct snd_pcm_substream *substream,
 112                 struct snd_pcm_hw_params *hw_params)
 113 {
 114         struct snd_pcm_runtime *runtime = substream->runtime;
 115         struct dw_i2s_dev *dev = runtime->private_data;
 116         int ret;
 117
 118         switch (params_channels(hw_params)) {
 119         case 2:
 120                 break;
 121         default:
 122                 dev_err(dev->dev, "invalid channels number\n");
 123                 return -EINVAL;
 124         }
 125
 126         switch (params_format(hw_params)) {
 127         case SNDRV_PCM_FORMAT_S16_LE:
 128                 dev->tx_fn = dw_pcm_tx_16;
 129                 break;
 130         case SNDRV_PCM_FORMAT_S32_LE:
 131                 dev->tx_fn = dw_pcm_tx_32;
 132                 break;
 133         default:
 134                 dev_err(dev->dev, "invalid format\n");
 135                 return -EINVAL;
 136         }
 137
 138         if (substream->stream != SNDRV_PCM_STREAM_PLAYBACK) {
 139                 dev_err(dev->dev, "only playback is available\n");
 140                 return -EINVAL;
 141         }
 142
 143         ret = snd_pcm_lib_malloc_pages(substream,
 144                         params_buffer_bytes(hw_params));
 145         if (ret < 0)
 146                 return ret;
 147         else
 148                 return 0;
 149 }
 150
 151 static int dw_pcm_hw_free(struct snd_pcm_substream *substream)
 152 {
 153         return snd_pcm_lib_free_pages(substream);
 154 }
 155
 156 static int dw_pcm_trigger(struct snd_pcm_substream *substream, int cmd)
 157 {
 158         struct snd_pcm_runtime *runtime = substream->runtime;
 159         struct dw_i2s_dev *dev = runtime->private_data;
 160         int ret = 0;
 161
 162         switch (cmd) {
 163         case SNDRV_PCM_TRIGGER_START:
 164         case SNDRV_PCM_TRIGGER_RESUME:
 165         case SNDRV_PCM_TRIGGER_PAUSE_RELEASE:
 166                 WRITE_ONCE(dev->tx_ptr, 0);
 167                 rcu_assign_pointer(dev->tx_substream, substream);
 168                 break;
 169         case SNDRV_PCM_TRIGGER_STOP:
 170         case SNDRV_PCM_TRIGGER_SUSPEND:
 171         case SNDRV_PCM_TRIGGER_PAUSE_PUSH:
 172                 rcu_assign_pointer(dev->tx_substream, NULL);
 173                 break;
 174         default:
 175                 ret = -EINVAL;
 176                 break;
 177         }
 178
 179         return ret;
 180 }
 181
 182 static snd_pcm_uframes_t dw_pcm_pointer(struct snd_pcm_substream *substream)
 183 {
 184         struct snd_pcm_runtime *runtime = substream->runtime;
 185         struct dw_i2s_dev *dev = runtime->private_data;
 186         snd_pcm_uframes_t pos = READ_ONCE(dev->tx_ptr);
 187
 188         return pos < runtime->buffer_size ? pos : 0;
 189 }
 190
 191 static int dw_pcm_new(struct snd_soc_pcm_runtime *rtd)
 192 {
 193         size_t size = dw_pcm_hardware.buffer_bytes_max;
 194
 195         return snd_pcm_lib_preallocate_pages_for_all(rtd->pcm,
 196                         SNDRV_DMA_TYPE_CONTINUOUS,
 197                         snd_dma_continuous_data(GFP_KERNEL), size, size);
 198 }
 199
 200 static void dw_pcm_free(struct snd_pcm *pcm)
 201 {
 202         snd_pcm_lib_preallocate_free_for_all(pcm);
 203 }
 204
 205 static const struct snd_pcm_ops dw_pcm_ops = {
 206         .open = dw_pcm_open,
 207         .close = dw_pcm_close,
 208         .ioctl = snd_pcm_lib_ioctl,
 209         .hw_params = dw_pcm_hw_params,
 210         .hw_free = dw_pcm_hw_free,
 211         .trigger = dw_pcm_trigger,
 212         .pointer = dw_pcm_pointer,
 213 };
 214
 215 static const struct snd_soc_platform_driver dw_pcm_platform = {
 216         .pcm_new = dw_pcm_new,
 217         .pcm_free = dw_pcm_free,
 218         .ops = &dw_pcm_ops,
 219 };
 220
 221 int dw_pcm_register(struct platform_device *pdev)
 222 {
 223         return devm_snd_soc_register_platform(&pdev->dev, &dw_pcm_platform);
 224 }
 225 EXPORT_SYMBOL_GPL(dw_pcm_register);