sound/soc/au1x/dma.c

   1 /*
   2  * Au1000/Au1500/Au1100 Audio DMA support.
   3  *
   4  * (c) 2011 Manuel Lauss <manuel.lauss@googlemail.com>
   5  *
   6  * copied almost verbatim from the old ALSA driver, written by
   7  *                      Charles Eidsness <charles@cooper-street.com>
   8  */
   9
  10 #include <linux/module.h>
  11 #include <linux/init.h>
  12 #include <linux/platform_device.h>
  13 #include <linux/slab.h>
  14 #include <linux/dma-mapping.h>
  15 #include <sound/core.h>
  16 #include <sound/pcm.h>
  17 #include <sound/pcm_params.h>
  18 #include <sound/soc.h>
  19 #include <asm/mach-au1x00/au1000.h>
  20 #include <asm/mach-au1x00/au1000_dma.h>
  21
  22 #include "psc.h"
  23
  24 struct pcm_period {
  25         u32 start;
  26         u32 relative_end;       /* relative to start of buffer */
  27         struct pcm_period *next;
  28 };
  29
  30 struct audio_stream {
  31         struct snd_pcm_substream *substream;
  32         int dma;
  33         struct pcm_period *buffer;
  34         unsigned int period_size;
  35         unsigned int periods;
  36 };
  37
  38 struct alchemy_pcm_ctx {
  39         struct audio_stream stream[2];  /* playback & capture */
  40 };
  41
  42 static void au1000_release_dma_link(struct audio_stream *stream)
  43 {
  44         struct pcm_period *pointer;
  45         struct pcm_period *pointer_next;
  46
  47         stream->period_size = 0;
  48         stream->periods = 0;
  49         pointer = stream->buffer;
  50         if (!pointer)
  51                 return;
  52         do {
  53                 pointer_next = pointer->next;
  54                 kfree(pointer);
  55                 pointer = pointer_next;
  56         } while (pointer != stream->buffer);
  57         stream->buffer = NULL;
  58 }
  59
  60 static int au1000_setup_dma_link(struct audio_stream *stream,
  61                                  unsigned int period_bytes,
  62                                  unsigned int periods)
  63 {
  64         struct snd_pcm_substream *substream = stream->substream;
  65         struct snd_pcm_runtime *runtime = substream->runtime;
  66         struct pcm_period *pointer;
  67         unsigned long dma_start;
  68         int i;
  69
  70         dma_start = virt_to_phys(runtime->dma_area);
  71
  72         if (stream->period_size == period_bytes &&
  73             stream->periods == periods)
  74                 return 0; /* not changed */
  75
  76         au1000_release_dma_link(stream);
  77
  78         stream->period_size = period_bytes;
  79         stream->periods = periods;
  80
  81         stream->buffer = kmalloc(sizeof(struct pcm_period), GFP_KERNEL);
  82         if (!stream->buffer)
  83                 return -ENOMEM;
  84         pointer = stream->buffer;
  85         for (i = 0; i < periods; i++) {
  86                 pointer->start = (u32)(dma_start + (i * period_bytes));
  87                 pointer->relative_end = (u32) (((i+1) * period_bytes) - 0x1);
  88                 if (i < periods - 1) {
  89                         pointer->next = kmalloc(sizeof(struct pcm_period),
  90                                                 GFP_KERNEL);
  91                         if (!pointer->next) {
  92                                 au1000_release_dma_link(stream);
  93                                 return -ENOMEM;
  94                         }
  95                         pointer = pointer->next;
  96                 }
  97         }
  98         pointer->next = stream->buffer;
  99         return 0;
 100 }
 101
 102 static void au1000_dma_stop(struct audio_stream *stream)
 103 {
 104         if (stream->buffer)
 105                 disable_dma(stream->dma);
 106 }
 107
 108 static void au1000_dma_start(struct audio_stream *stream)
 109 {
 110         if (!stream->buffer)
 111                 return;
 112
 113         init_dma(stream->dma);
 114         if (get_dma_active_buffer(stream->dma) == 0) {
 115                 clear_dma_done0(stream->dma);
 116                 set_dma_addr0(stream->dma, stream->buffer->start);
 117                 set_dma_count0(stream->dma, stream->period_size >> 1);
 118                 set_dma_addr1(stream->dma, stream->buffer->next->start);
 119                 set_dma_count1(stream->dma, stream->period_size >> 1);
 120         } else {
 121                 clear_dma_done1(stream->dma);
 122                 set_dma_addr1(stream->dma, stream->buffer->start);
 123                 set_dma_count1(stream->dma, stream->period_size >> 1);
 124                 set_dma_addr0(stream->dma, stream->buffer->next->start);
 125                 set_dma_count0(stream->dma, stream->period_size >> 1);
 126         }
 127         enable_dma_buffers(stream->dma);
 128         start_dma(stream->dma);
 129 }
 130
 131 static irqreturn_t au1000_dma_interrupt(int irq, void *ptr)
 132 {
 133         struct audio_stream *stream = (struct audio_stream *)ptr;
 134         struct snd_pcm_substream *substream = stream->substream;
 135
 136         switch (get_dma_buffer_done(stream->dma)) {
 137         case DMA_D0:
 138                 stream->buffer = stream->buffer->next;
 139                 clear_dma_done0(stream->dma);
 140                 set_dma_addr0(stream->dma, stream->buffer->next->start);
 141                 set_dma_count0(stream->dma, stream->period_size >> 1);
 142                 enable_dma_buffer0(stream->dma);
 143                 break;
 144         case DMA_D1:
 145                 stream->buffer = stream->buffer->next;
 146                 clear_dma_done1(stream->dma);
 147                 set_dma_addr1(stream->dma, stream->buffer->next->start);
 148                 set_dma_count1(stream->dma, stream->period_size >> 1);
 149                 enable_dma_buffer1(stream->dma);
 150                 break;
 151         case (DMA_D0 | DMA_D1):
 152                 pr_debug("DMA %d missed interrupt.\n", stream->dma);
 153                 au1000_dma_stop(stream);
 154                 au1000_dma_start(stream);
 155                 break;
 156         case (~DMA_D0 & ~DMA_D1):
 157                 pr_debug("DMA %d empty irq.\n", stream->dma);
 158         }
 159         snd_pcm_period_elapsed(substream);
 160         return IRQ_HANDLED;
 161 }
 162
 163 static const struct snd_pcm_hardware alchemy_pcm_hardware = {
 164         .info             = SNDRV_PCM_INFO_MMAP | SNDRV_PCM_INFO_MMAP_VALID |
 165                             SNDRV_PCM_INFO_INTERLEAVED | SNDRV_PCM_INFO_BATCH,
 166         .period_bytes_min = 1024,
 167         .period_bytes_max = 16 * 1024 - 1,
 168         .periods_min      = 4,
 169         .periods_max      = 255,
 170         .buffer_bytes_max = 128 * 1024,
 171         .fifo_size        = 16,
 172 };
 173
 174 static inline struct alchemy_pcm_ctx *ss_to_ctx(struct snd_pcm_substream *ss)
 175 {
 176         struct snd_soc_pcm_runtime *rtd = ss->private_data;
 177         return snd_soc_platform_get_drvdata(rtd->platform);
 178 }
 179
 180 static inline struct audio_stream *ss_to_as(struct snd_pcm_substream *ss)
 181 {
 182         struct alchemy_pcm_ctx *ctx = ss_to_ctx(ss);
 183         return &(ctx->stream[ss->stream]);
 184 }
 185
 186 static int alchemy_pcm_open(struct snd_pcm_substream *substream)
 187 {
 188         struct alchemy_pcm_ctx *ctx = ss_to_ctx(substream);
 189         struct snd_soc_pcm_runtime *rtd = substream->private_data;
 190         int *dmaids, s = substream->stream;
 191         char *name;
 192
 193         dmaids = snd_soc_dai_get_dma_data(rtd->cpu_dai, substream);
 194         if (!dmaids)
 195                 return -ENODEV; /* whoa, has ordering changed? */
 196
 197         /* DMA setup */
 198         name = (s == SNDRV_PCM_STREAM_PLAYBACK) ? "audio-tx" : "audio-rx";
 199         ctx->stream[s].dma = request_au1000_dma(dmaids[s], name,
 200                                         au1000_dma_interrupt, 0,
 201                                         &ctx->stream[s]);
 202         set_dma_mode(ctx->stream[s].dma,
 203                      get_dma_mode(ctx->stream[s].dma) & ~DMA_NC);
 204
 205         ctx->stream[s].substream = substream;
 206         ctx->stream[s].buffer = NULL;
 207         snd_soc_set_runtime_hwparams(substream, &alchemy_pcm_hardware);
 208
 209         return 0;
 210 }
 211
 212 static int alchemy_pcm_close(struct snd_pcm_substream *substream)
 213 {
 214         struct alchemy_pcm_ctx *ctx = ss_to_ctx(substream);
 215         int stype = substream->stream;
 216
 217         ctx->stream[stype].substream = NULL;
 218         free_au1000_dma(ctx->stream[stype].dma);
 219
 220         return 0;
 221 }
 222
 223 static int alchemy_pcm_hw_params(struct snd_pcm_substream *substream,
 224                                  struct snd_pcm_hw_params *hw_params)
 225 {
 226         struct audio_stream *stream = ss_to_as(substream);
 227         int err;
 228
 229         err = snd_pcm_lib_malloc_pages(substream,
 230                                        params_buffer_bytes(hw_params));
 231         if (err < 0)
 232                 return err;
 233         err = au1000_setup_dma_link(stream,
 234                                     params_period_bytes(hw_params),
 235                                     params_periods(hw_params));
 236         if (err)
 237                 snd_pcm_lib_free_pages(substream);
 238
 239         return err;
 240 }
 241
 242 static int alchemy_pcm_hw_free(struct snd_pcm_substream *substream)
 243 {
 244         struct audio_stream *stream = ss_to_as(substream);
 245         au1000_release_dma_link(stream);
 246         return snd_pcm_lib_free_pages(substream);
 247 }
 248
 249 static int alchemy_pcm_trigger(struct snd_pcm_substream *substream, int cmd)
 250 {
 251         struct audio_stream *stream = ss_to_as(substream);
 252         int err = 0;
 253
 254         switch (cmd) {
 255         case SNDRV_PCM_TRIGGER_START:
 256                 au1000_dma_start(stream);
 257                 break;
 258         case SNDRV_PCM_TRIGGER_STOP:
 259                 au1000_dma_stop(stream);
 260                 break;
 261         default:
 262                 err = -EINVAL;
 263                 break;
 264         }
 265         return err;
 266 }
 267
 268 static snd_pcm_uframes_t alchemy_pcm_pointer(struct snd_pcm_substream *ss)
 269 {
 270         struct audio_stream *stream = ss_to_as(ss);
 271         long location;
 272
 273         location = get_dma_residue(stream->dma);
 274         location = stream->buffer->relative_end - location;
 275         if (location == -1)
 276                 location = 0;
 277         return bytes_to_frames(ss->runtime, location);
 278 }
 279
 280 static struct snd_pcm_ops alchemy_pcm_ops = {
 281         .open                   = alchemy_pcm_open,
 282         .close                  = alchemy_pcm_close,
 283         .ioctl                  = snd_pcm_lib_ioctl,
 284         .hw_params              = alchemy_pcm_hw_params,
 285         .hw_free                = alchemy_pcm_hw_free,
 286         .trigger                = alchemy_pcm_trigger,
 287         .pointer                = alchemy_pcm_pointer,
 288 };
 289
 290 static int alchemy_pcm_new(struct snd_soc_pcm_runtime *rtd)
 291 {
 292         struct snd_pcm *pcm = rtd->pcm;
 293
 294         snd_pcm_lib_preallocate_pages_for_all(pcm, SNDRV_DMA_TYPE_CONTINUOUS,
 295                 snd_dma_continuous_data(GFP_KERNEL), 65536, (4096 * 1024) - 1);
 296
 297         return 0;
 298 }
 299
 300 static struct snd_soc_platform_driver alchemy_pcm_soc_platform = {
 301         .ops            = &alchemy_pcm_ops,
 302         .pcm_new        = alchemy_pcm_new,
 303 };
 304
 305 static int alchemy_pcm_drvprobe(struct platform_device *pdev)
 306 {
 307         struct alchemy_pcm_ctx *ctx;
 308
 309         ctx = devm_kzalloc(&pdev->dev, sizeof(*ctx), GFP_KERNEL);
 310         if (!ctx)
 311                 return -ENOMEM;
 312
 313         platform_set_drvdata(pdev, ctx);
 314
 315         return devm_snd_soc_register_platform(&pdev->dev,
 316                                               &alchemy_pcm_soc_platform);
 317 }
 318
 319 static struct platform_driver alchemy_pcmdma_driver = {
 320         .driver = {
 321                 .name   = "alchemy-pcm-dma",
 322         },
 323         .probe          = alchemy_pcm_drvprobe,
 324 };
 325
 326 module_platform_driver(alchemy_pcmdma_driver);
 327
 328 MODULE_LICENSE("GPL");
 329 MODULE_DESCRIPTION("Au1000/Au1500/Au1100 Audio DMA driver");
 330 MODULE_AUTHOR("Manuel Lauss");