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 #define DRV_NAME "au1x_dma"
  25
  26 struct pcm_period {
  27         u32 start;
  28         u32 relative_end;       /* relative to start of buffer */
  29         struct pcm_period *next;
  30 };
  31
  32 struct audio_stream {
  33         struct snd_pcm_substream *substream;
  34         int dma;
  35         struct pcm_period *buffer;
  36         unsigned int period_size;
  37         unsigned int periods;
  38 };
  39
  40 struct alchemy_pcm_ctx {
  41         struct audio_stream stream[2];  /* playback & capture */
  42 };
  43
  44 static void au1000_release_dma_link(struct audio_stream *stream)
  45 {
  46         struct pcm_period *pointer;
  47         struct pcm_period *pointer_next;
  48
  49         stream->period_size = 0;
  50         stream->periods = 0;
  51         pointer = stream->buffer;
  52         if (!pointer)
  53                 return;
  54         do {
  55                 pointer_next = pointer->next;
  56                 kfree(pointer);
  57                 pointer = pointer_next;
  58         } while (pointer != stream->buffer);
  59         stream->buffer = NULL;
  60 }
  61
  62 static int au1000_setup_dma_link(struct audio_stream *stream,
  63                                  unsigned int period_bytes,
  64                                  unsigned int periods)
  65 {
  66         struct snd_pcm_substream *substream = stream->substream;
  67         struct snd_pcm_runtime *runtime = substream->runtime;
  68         struct pcm_period *pointer;
  69         unsigned long dma_start;
  70         int i;
  71
  72         dma_start = virt_to_phys(runtime->dma_area);
  73
  74         if (stream->period_size == period_bytes &&
  75             stream->periods == periods)
  76                 return 0; /* not changed */
  77
  78         au1000_release_dma_link(stream);
  79
  80         stream->period_size = period_bytes;
  81         stream->periods = periods;
  82
  83         stream->buffer = kmalloc(sizeof(struct pcm_period), GFP_KERNEL);
  84         if (!stream->buffer)
  85                 return -ENOMEM;
  86         pointer = stream->buffer;
  87         for (i = 0; i < periods; i++) {
  88                 pointer->start = (u32)(dma_start + (i * period_bytes));
  89                 pointer->relative_end = (u32) (((i+1) * period_bytes) - 0x1);
  90                 if (i < periods - 1) {
  91                         pointer->next = kmalloc(sizeof(struct pcm_period),
  92                                                 GFP_KERNEL);
  93                         if (!pointer->next) {
  94                                 au1000_release_dma_link(stream);
  95                                 return -ENOMEM;
  96                         }
  97                         pointer = pointer->next;
  98                 }
  99         }
 100         pointer->next = stream->buffer;
 101         return 0;
 102 }
 103
 104 static void au1000_dma_stop(struct audio_stream *stream)
 105 {
 106         if (stream->buffer)
 107                 disable_dma(stream->dma);
 108 }
 109
 110 static void au1000_dma_start(struct audio_stream *stream)
 111 {
 112         if (!stream->buffer)
 113                 return;
 114
 115         init_dma(stream->dma);
 116         if (get_dma_active_buffer(stream->dma) == 0) {
 117                 clear_dma_done0(stream->dma);
 118                 set_dma_addr0(stream->dma, stream->buffer->start);
 119                 set_dma_count0(stream->dma, stream->period_size >> 1);
 120                 set_dma_addr1(stream->dma, stream->buffer->next->start);
 121                 set_dma_count1(stream->dma, stream->period_size >> 1);
 122         } else {
 123                 clear_dma_done1(stream->dma);
 124                 set_dma_addr1(stream->dma, stream->buffer->start);
 125                 set_dma_count1(stream->dma, stream->period_size >> 1);
 126                 set_dma_addr0(stream->dma, stream->buffer->next->start);
 127                 set_dma_count0(stream->dma, stream->period_size >> 1);
 128         }
 129         enable_dma_buffers(stream->dma);
 130         start_dma(stream->dma);
 131 }
 132
 133 static irqreturn_t au1000_dma_interrupt(int irq, void *ptr)
 134 {
 135         struct audio_stream *stream = (struct audio_stream *)ptr;
 136         struct snd_pcm_substream *substream = stream->substream;
 137
 138         switch (get_dma_buffer_done(stream->dma)) {
 139         case DMA_D0:
 140                 stream->buffer = stream->buffer->next;
 141                 clear_dma_done0(stream->dma);
 142                 set_dma_addr0(stream->dma, stream->buffer->next->start);
 143                 set_dma_count0(stream->dma, stream->period_size >> 1);
 144                 enable_dma_buffer0(stream->dma);
 145                 break;
 146         case DMA_D1:
 147                 stream->buffer = stream->buffer->next;
 148                 clear_dma_done1(stream->dma);
 149                 set_dma_addr1(stream->dma, stream->buffer->next->start);
 150                 set_dma_count1(stream->dma, stream->period_size >> 1);
 151                 enable_dma_buffer1(stream->dma);
 152                 break;
 153         case (DMA_D0 | DMA_D1):
 154                 pr_debug("DMA %d missed interrupt.\n", stream->dma);
 155                 au1000_dma_stop(stream);
 156                 au1000_dma_start(stream);
 157                 break;
 158         case (~DMA_D0 & ~DMA_D1):
 159                 pr_debug("DMA %d empty irq.\n", stream->dma);
 160         }
 161         snd_pcm_period_elapsed(substream);
 162         return IRQ_HANDLED;
 163 }
 164
 165 static const struct snd_pcm_hardware alchemy_pcm_hardware = {
 166         .info             = SNDRV_PCM_INFO_MMAP | SNDRV_PCM_INFO_MMAP_VALID |
 167                             SNDRV_PCM_INFO_INTERLEAVED | SNDRV_PCM_INFO_BATCH,
 168         .period_bytes_min = 1024,
 169         .period_bytes_max = 16 * 1024 - 1,
 170         .periods_min      = 4,
 171         .periods_max      = 255,
 172         .buffer_bytes_max = 128 * 1024,
 173         .fifo_size        = 16,
 174 };
 175
 176 static inline struct alchemy_pcm_ctx *ss_to_ctx(struct snd_pcm_substream *ss)
 177 {
 178         struct snd_soc_pcm_runtime *rtd = ss->private_data;
 179         struct snd_soc_component *component = snd_soc_rtdcom_lookup(rtd, DRV_NAME);
 180         return snd_soc_component_get_drvdata(component);
 181 }
 182
 183 static inline struct audio_stream *ss_to_as(struct snd_pcm_substream *ss)
 184 {
 185         struct alchemy_pcm_ctx *ctx = ss_to_ctx(ss);
 186         return &(ctx->stream[ss->stream]);
 187 }
 188
 189 static int alchemy_pcm_open(struct snd_pcm_substream *substream)
 190 {
 191         struct alchemy_pcm_ctx *ctx = ss_to_ctx(substream);
 192         struct snd_soc_pcm_runtime *rtd = substream->private_data;
 193         int *dmaids, s = substream->stream;
 194         char *name;
 195
 196         dmaids = snd_soc_dai_get_dma_data(rtd->cpu_dai, substream);
 197         if (!dmaids)
 198                 return -ENODEV; /* whoa, has ordering changed? */
 199
 200         /* DMA setup */
 201         name = (s == SNDRV_PCM_STREAM_PLAYBACK) ? "audio-tx" : "audio-rx";
 202         ctx->stream[s].dma = request_au1000_dma(dmaids[s], name,
 203                                         au1000_dma_interrupt, 0,
 204                                         &ctx->stream[s]);
 205         set_dma_mode(ctx->stream[s].dma,
 206                      get_dma_mode(ctx->stream[s].dma) & ~DMA_NC);
 207
 208         ctx->stream[s].substream = substream;
 209         ctx->stream[s].buffer = NULL;
 210         snd_soc_set_runtime_hwparams(substream, &alchemy_pcm_hardware);
 211
 212         return 0;
 213 }
 214
 215 static int alchemy_pcm_close(struct snd_pcm_substream *substream)
 216 {
 217         struct alchemy_pcm_ctx *ctx = ss_to_ctx(substream);
 218         int stype = substream->stream;
 219
 220         ctx->stream[stype].substream = NULL;
 221         free_au1000_dma(ctx->stream[stype].dma);
 222
 223         return 0;
 224 }
 225
 226 static int alchemy_pcm_hw_params(struct snd_pcm_substream *substream,
 227                                  struct snd_pcm_hw_params *hw_params)
 228 {
 229         struct audio_stream *stream = ss_to_as(substream);
 230         int err;
 231
 232         err = snd_pcm_lib_malloc_pages(substream,
 233                                        params_buffer_bytes(hw_params));
 234         if (err < 0)
 235                 return err;
 236         err = au1000_setup_dma_link(stream,
 237                                     params_period_bytes(hw_params),
 238                                     params_periods(hw_params));
 239         if (err)
 240                 snd_pcm_lib_free_pages(substream);
 241
 242         return err;
 243 }
 244
 245 static int alchemy_pcm_hw_free(struct snd_pcm_substream *substream)
 246 {
 247         struct audio_stream *stream = ss_to_as(substream);
 248         au1000_release_dma_link(stream);
 249         return snd_pcm_lib_free_pages(substream);
 250 }
 251
 252 static int alchemy_pcm_trigger(struct snd_pcm_substream *substream, int cmd)
 253 {
 254         struct audio_stream *stream = ss_to_as(substream);
 255         int err = 0;
 256
 257         switch (cmd) {
 258         case SNDRV_PCM_TRIGGER_START:
 259                 au1000_dma_start(stream);
 260                 break;
 261         case SNDRV_PCM_TRIGGER_STOP:
 262                 au1000_dma_stop(stream);
 263                 break;
 264         default:
 265                 err = -EINVAL;
 266                 break;
 267         }
 268         return err;
 269 }
 270
 271 static snd_pcm_uframes_t alchemy_pcm_pointer(struct snd_pcm_substream *ss)
 272 {
 273         struct audio_stream *stream = ss_to_as(ss);
 274         long location;
 275
 276         location = get_dma_residue(stream->dma);
 277         location = stream->buffer->relative_end - location;
 278         if (location == -1)
 279                 location = 0;
 280         return bytes_to_frames(ss->runtime, location);
 281 }
 282
 283 static const struct snd_pcm_ops alchemy_pcm_ops = {
 284         .open                   = alchemy_pcm_open,
 285         .close                  = alchemy_pcm_close,
 286         .ioctl                  = snd_pcm_lib_ioctl,
 287         .hw_params              = alchemy_pcm_hw_params,
 288         .hw_free                = alchemy_pcm_hw_free,
 289         .trigger                = alchemy_pcm_trigger,
 290         .pointer                = alchemy_pcm_pointer,
 291 };
 292
 293 static int alchemy_pcm_new(struct snd_soc_pcm_runtime *rtd)
 294 {
 295         struct snd_pcm *pcm = rtd->pcm;
 296
 297         snd_pcm_lib_preallocate_pages_for_all(pcm, SNDRV_DMA_TYPE_CONTINUOUS,
 298                 snd_dma_continuous_data(GFP_KERNEL), 65536, (4096 * 1024) - 1);
 299
 300         return 0;
 301 }
 302
 303 static struct snd_soc_component_driver alchemy_pcm_soc_component = {
 304         .name           = DRV_NAME,
 305         .ops            = &alchemy_pcm_ops,
 306         .pcm_new        = alchemy_pcm_new,
 307 };
 308
 309 static int alchemy_pcm_drvprobe(struct platform_device *pdev)
 310 {
 311         struct alchemy_pcm_ctx *ctx;
 312
 313         ctx = devm_kzalloc(&pdev->dev, sizeof(*ctx), GFP_KERNEL);
 314         if (!ctx)
 315                 return -ENOMEM;
 316
 317         platform_set_drvdata(pdev, ctx);
 318
 319         return devm_snd_soc_register_component(&pdev->dev,
 320                                         &alchemy_pcm_soc_component, NULL, 0);
 321 }
 322
 323 static struct platform_driver alchemy_pcmdma_driver = {
 324         .driver = {
 325                 .name   = "alchemy-pcm-dma",
 326         },
 327         .probe          = alchemy_pcm_drvprobe,
 328 };
 329
 330 module_platform_driver(alchemy_pcmdma_driver);
 331
 332 MODULE_LICENSE("GPL");
 333 MODULE_DESCRIPTION("Au1000/Au1500/Au1100 Audio DMA driver");
 334 MODULE_AUTHOR("Manuel Lauss");