sound/soc/at91/at91-pcm.c

   1 /*
   2  * at91-pcm.c -- ALSA PCM interface for the Atmel AT91 SoC
   3  *
   4  * Author:      Frank Mandarino <fmandarino@endrelia.com>
   5  *              Endrelia Technologies Inc.
   6  * Created:     Mar 3, 2006
   7  *
   8  * Based on pxa2xx-pcm.c by:
   9  *
  10  * Author:      Nicolas Pitre
  11  * Created:     Nov 30, 2004
  12  * Copyright:   (C) 2004 MontaVista Software, Inc.
  13  *
  14  * This program is free software; you can redistribute it and/or modify
  15  * it under the terms of the GNU General Public License version 2 as
  16  * published by the Free Software Foundation.
  17  */
  18
  19 #include <linux/module.h>
  20 #include <linux/init.h>
  21 #include <linux/platform_device.h>
  22 #include <linux/slab.h>
  23 #include <linux/dma-mapping.h>
  24 #include <linux/atmel_pdc.h>
  25
  26 #include <sound/core.h>
  27 #include <sound/pcm.h>
  28 #include <sound/pcm_params.h>
  29 #include <sound/soc.h>
  30
  31 #include <asm/arch/hardware.h>
  32 #include <asm/arch/at91_ssc.h>
  33
  34 #include "at91-pcm.h"
  35
  36 #if 0
  37 #define DBG(x...)       printk(KERN_INFO "at91-pcm: " x)
  38 #else
  39 #define DBG(x...)
  40 #endif
  41
  42 static const struct snd_pcm_hardware at91_pcm_hardware = {
  43         .info                   = SNDRV_PCM_INFO_MMAP |
  44                                   SNDRV_PCM_INFO_MMAP_VALID |
  45                                   SNDRV_PCM_INFO_INTERLEAVED |
  46                                   SNDRV_PCM_INFO_PAUSE,
  47         .formats                = SNDRV_PCM_FMTBIT_S16_LE,
  48         .period_bytes_min       = 32,
  49         .period_bytes_max       = 8192,
  50         .periods_min            = 2,
  51         .periods_max            = 1024,
  52         .buffer_bytes_max       = 32 * 1024,
  53 };
  54
  55 struct at91_runtime_data {
  56         struct at91_pcm_dma_params *params;
  57         dma_addr_t dma_buffer;                  /* physical address of dma buffer */
  58         dma_addr_t dma_buffer_end;              /* first address beyond DMA buffer */
  59         size_t period_size;
  60         dma_addr_t period_ptr;                  /* physical address of next period */
  61         u32 pdc_xpr_save;                       /* PDC register save */
  62         u32 pdc_xcr_save;
  63         u32 pdc_xnpr_save;
  64         u32 pdc_xncr_save;
  65 };
  66
  67 static void at91_pcm_dma_irq(u32 ssc_sr,
  68         struct snd_pcm_substream *substream)
  69 {
  70         struct at91_runtime_data *prtd = substream->runtime->private_data;
  71         struct at91_pcm_dma_params *params = prtd->params;
  72         static int count = 0;
  73
  74         count++;
  75
  76         if (ssc_sr & params->mask->ssc_endbuf) {
  77
  78                 printk(KERN_WARNING
  79                         "at91-pcm: buffer %s on %s (SSC_SR=%#x, count=%d)\n",
  80                         substream->stream == SNDRV_PCM_STREAM_PLAYBACK
  81                                 ? "underrun" : "overrun",
  82                         params->name, ssc_sr, count);
  83
  84                 /* re-start the PDC */
  85                 at91_ssc_write(params->ssc_base + ATMEL_PDC_PTCR, params->mask->pdc_disable);
  86
  87                 prtd->period_ptr += prtd->period_size;
  88                 if (prtd->period_ptr >= prtd->dma_buffer_end) {
  89                         prtd->period_ptr = prtd->dma_buffer;
  90                 }
  91
  92                 at91_ssc_write(params->ssc_base + params->pdc->xpr, prtd->period_ptr);
  93                 at91_ssc_write(params->ssc_base + params->pdc->xcr,
  94                                 prtd->period_size / params->pdc_xfer_size);
  95
  96                 at91_ssc_write(params->ssc_base + ATMEL_PDC_PTCR, params->mask->pdc_enable);
  97         }
  98
  99         if (ssc_sr & params->mask->ssc_endx) {
 100
 101                 /* Load the PDC next pointer and counter registers */
 102                 prtd->period_ptr += prtd->period_size;
 103                 if (prtd->period_ptr >= prtd->dma_buffer_end) {
 104                         prtd->period_ptr = prtd->dma_buffer;
 105                 }
 106                 at91_ssc_write(params->ssc_base + params->pdc->xnpr,
 107                                prtd->period_ptr);
 108                 at91_ssc_write(params->ssc_base + params->pdc->xncr,
 109                                 prtd->period_size / params->pdc_xfer_size);
 110         }
 111
 112         snd_pcm_period_elapsed(substream);
 113 }
 114
 115 static int at91_pcm_hw_params(struct snd_pcm_substream *substream,
 116         struct snd_pcm_hw_params *params)
 117 {
 118         struct snd_pcm_runtime *runtime = substream->runtime;
 119         struct at91_runtime_data *prtd = runtime->private_data;
 120         struct snd_soc_pcm_runtime *rtd = substream->private_data;
 121
 122         /* this may get called several times by oss emulation
 123          * with different params */
 124
 125         snd_pcm_set_runtime_buffer(substream, &substream->dma_buffer);
 126         runtime->dma_bytes = params_buffer_bytes(params);
 127
 128         prtd->params = rtd->dai->cpu_dai->dma_data;
 129         prtd->params->dma_intr_handler = at91_pcm_dma_irq;
 130
 131         prtd->dma_buffer = runtime->dma_addr;
 132         prtd->dma_buffer_end = runtime->dma_addr + runtime->dma_bytes;
 133         prtd->period_size = params_period_bytes(params);
 134
 135         DBG("hw_params: DMA for %s initialized (dma_bytes=%d, period_size=%d)\n",
 136                 prtd->params->name, runtime->dma_bytes, prtd->period_size);
 137         return 0;
 138 }
 139
 140 static int at91_pcm_hw_free(struct snd_pcm_substream *substream)
 141 {
 142         struct at91_runtime_data *prtd = substream->runtime->private_data;
 143         struct at91_pcm_dma_params *params = prtd->params;
 144
 145         if (params != NULL) {
 146                 at91_ssc_write(params->ssc_base + ATMEL_PDC_PTCR, params->mask->pdc_disable);
 147                 prtd->params->dma_intr_handler = NULL;
 148         }
 149
 150         return 0;
 151 }
 152
 153 static int at91_pcm_prepare(struct snd_pcm_substream *substream)
 154 {
 155         struct at91_runtime_data *prtd = substream->runtime->private_data;
 156         struct at91_pcm_dma_params *params = prtd->params;
 157
 158         at91_ssc_write(params->ssc_base + AT91_SSC_IDR,
 159                         params->mask->ssc_endx | params->mask->ssc_endbuf);
 160
 161         at91_ssc_write(params->ssc_base + ATMEL_PDC_PTCR, params->mask->pdc_disable);
 162         return 0;
 163 }
 164
 165 static int at91_pcm_trigger(struct snd_pcm_substream *substream,
 166         int cmd)
 167 {
 168         struct at91_runtime_data *prtd = substream->runtime->private_data;
 169         struct at91_pcm_dma_params *params = prtd->params;
 170         int ret = 0;
 171
 172         switch (cmd) {
 173         case SNDRV_PCM_TRIGGER_START:
 174                 prtd->period_ptr = prtd->dma_buffer;
 175
 176                 at91_ssc_write(params->ssc_base + params->pdc->xpr, prtd->period_ptr);
 177                 at91_ssc_write(params->ssc_base + params->pdc->xcr,
 178                                 prtd->period_size / params->pdc_xfer_size);
 179
 180                 prtd->period_ptr += prtd->period_size;
 181                 at91_ssc_write(params->ssc_base + params->pdc->xnpr, prtd->period_ptr);
 182                 at91_ssc_write(params->ssc_base + params->pdc->xncr,
 183                                 prtd->period_size / params->pdc_xfer_size);
 184
 185                 DBG("trigger: period_ptr=%lx, xpr=%lx, xcr=%ld, xnpr=%lx, xncr=%ld\n",
 186                         (unsigned long) prtd->period_ptr,
 187                         at91_ssc_read(params->ssc_base + params->pdc->xpr),
 188                         at91_ssc_read(params->ssc_base + params->pdc->xcr),
 189                         at91_ssc_read(params->ssc_base + params->pdc->xnpr),
 190                         at91_ssc_read(params->ssc_base + params->pdc->xncr));
 191
 192                 at91_ssc_write(params->ssc_base + AT91_SSC_IER,
 193                         params->mask->ssc_endx | params->mask->ssc_endbuf);
 194
 195                 at91_ssc_write(params->ssc_base + ATMEL_PDC_PTCR,
 196                         params->mask->pdc_enable);
 197
 198                 DBG("sr=%lx imr=%lx\n",
 199                     at91_ssc_read(params->ssc_base + AT91_SSC_SR),
 200                     at91_ssc_read(params->ssc_base + AT91_SSC_IER));
 201                 break;
 202
 203         case SNDRV_PCM_TRIGGER_STOP:
 204         case SNDRV_PCM_TRIGGER_SUSPEND:
 205         case SNDRV_PCM_TRIGGER_PAUSE_PUSH:
 206                 at91_ssc_write(params->ssc_base + ATMEL_PDC_PTCR, params->mask->pdc_disable);
 207                 break;
 208
 209         case SNDRV_PCM_TRIGGER_RESUME:
 210         case SNDRV_PCM_TRIGGER_PAUSE_RELEASE:
 211                 at91_ssc_write(params->ssc_base + ATMEL_PDC_PTCR, params->mask->pdc_enable);
 212                 break;
 213
 214         default:
 215                 ret = -EINVAL;
 216         }
 217
 218         return ret;
 219 }
 220
 221 static snd_pcm_uframes_t at91_pcm_pointer(
 222         struct snd_pcm_substream *substream)
 223 {
 224         struct snd_pcm_runtime *runtime = substream->runtime;
 225         struct at91_runtime_data *prtd = runtime->private_data;
 226         struct at91_pcm_dma_params *params = prtd->params;
 227         dma_addr_t ptr;
 228         snd_pcm_uframes_t x;
 229
 230         ptr = (dma_addr_t) at91_ssc_read(params->ssc_base + params->pdc->xpr);
 231         x = bytes_to_frames(runtime, ptr - prtd->dma_buffer);
 232
 233         if (x == runtime->buffer_size)
 234                 x = 0;
 235         return x;
 236 }
 237
 238 static int at91_pcm_open(struct snd_pcm_substream *substream)
 239 {
 240         struct snd_pcm_runtime *runtime = substream->runtime;
 241         struct at91_runtime_data *prtd;
 242         int ret = 0;
 243
 244         snd_soc_set_runtime_hwparams(substream, &at91_pcm_hardware);
 245
 246         /* ensure that buffer size is a multiple of period size */
 247         ret = snd_pcm_hw_constraint_integer(runtime, SNDRV_PCM_HW_PARAM_PERIODS);
 248         if (ret < 0)
 249                 goto out;
 250
 251         prtd = kzalloc(sizeof(struct at91_runtime_data), GFP_KERNEL);
 252         if (prtd == NULL) {
 253                 ret = -ENOMEM;
 254                 goto out;
 255         }
 256         runtime->private_data = prtd;
 257
 258  out:
 259         return ret;
 260 }
 261
 262 static int at91_pcm_close(struct snd_pcm_substream *substream)
 263 {
 264         struct at91_runtime_data *prtd = substream->runtime->private_data;
 265
 266         kfree(prtd);
 267         return 0;
 268 }
 269
 270 static int at91_pcm_mmap(struct snd_pcm_substream *substream,
 271         struct vm_area_struct *vma)
 272 {
 273         struct snd_pcm_runtime *runtime = substream->runtime;
 274
 275         return dma_mmap_writecombine(substream->pcm->card->dev, vma,
 276                                      runtime->dma_area,
 277                                      runtime->dma_addr,
 278                                      runtime->dma_bytes);
 279 }
 280
 281 struct snd_pcm_ops at91_pcm_ops = {
 282         .open           = at91_pcm_open,
 283         .close          = at91_pcm_close,
 284         .ioctl          = snd_pcm_lib_ioctl,
 285         .hw_params      = at91_pcm_hw_params,
 286         .hw_free        = at91_pcm_hw_free,
 287         .prepare        = at91_pcm_prepare,
 288         .trigger        = at91_pcm_trigger,
 289         .pointer        = at91_pcm_pointer,
 290         .mmap           = at91_pcm_mmap,
 291 };
 292
 293 static int at91_pcm_preallocate_dma_buffer(struct snd_pcm *pcm,
 294         int stream)
 295 {
 296         struct snd_pcm_substream *substream = pcm->streams[stream].substream;
 297         struct snd_dma_buffer *buf = &substream->dma_buffer;
 298         size_t size = at91_pcm_hardware.buffer_bytes_max;
 299
 300         buf->dev.type = SNDRV_DMA_TYPE_DEV;
 301         buf->dev.dev = pcm->card->dev;
 302         buf->private_data = NULL;
 303         buf->area = dma_alloc_writecombine(pcm->card->dev, size,
 304                                            &buf->addr, GFP_KERNEL);
 305
 306         DBG("preallocate_dma_buffer: area=%p, addr=%p, size=%d\n",
 307                 (void *) buf->area,
 308                 (void *) buf->addr,
 309                 size);
 310
 311         if (!buf->area)
 312                 return -ENOMEM;
 313
 314         buf->bytes = size;
 315         return 0;
 316 }
 317
 318 static u64 at91_pcm_dmamask = 0xffffffff;
 319
 320 static int at91_pcm_new(struct snd_card *card,
 321         struct snd_soc_codec_dai *dai, struct snd_pcm *pcm)
 322 {
 323         int ret = 0;
 324
 325         if (!card->dev->dma_mask)
 326                 card->dev->dma_mask = &at91_pcm_dmamask;
 327         if (!card->dev->coherent_dma_mask)
 328                 card->dev->coherent_dma_mask = 0xffffffff;
 329
 330         if (dai->playback.channels_min) {
 331                 ret = at91_pcm_preallocate_dma_buffer(pcm,
 332                         SNDRV_PCM_STREAM_PLAYBACK);
 333                 if (ret)
 334                         goto out;
 335         }
 336
 337         if (dai->capture.channels_min) {
 338                 ret = at91_pcm_preallocate_dma_buffer(pcm,
 339                         SNDRV_PCM_STREAM_CAPTURE);
 340                 if (ret)
 341                         goto out;
 342         }
 343  out:
 344         return ret;
 345 }
 346
 347 static void at91_pcm_free_dma_buffers(struct snd_pcm *pcm)
 348 {
 349         struct snd_pcm_substream *substream;
 350         struct snd_dma_buffer *buf;
 351         int stream;
 352
 353         for (stream = 0; stream < 2; stream++) {
 354                 substream = pcm->streams[stream].substream;
 355                 if (!substream)
 356                         continue;
 357
 358                 buf = &substream->dma_buffer;
 359                 if (!buf->area)
 360                         continue;
 361
 362                 dma_free_writecombine(pcm->card->dev, buf->bytes,
 363                                       buf->area, buf->addr);
 364                 buf->area = NULL;
 365         }
 366 }
 367
 368 #ifdef CONFIG_PM
 369 static int at91_pcm_suspend(struct platform_device *pdev,
 370         struct snd_soc_cpu_dai *dai)
 371 {
 372         struct snd_pcm_runtime *runtime = dai->runtime;
 373         struct at91_runtime_data *prtd;
 374         struct at91_pcm_dma_params *params;
 375
 376         if (!runtime)
 377                 return 0;
 378
 379         prtd = runtime->private_data;
 380         params = prtd->params;
 381
 382         /* disable the PDC and save the PDC registers */
 383
 384         at91_ssc_write(params->ssc_base + ATMEL_PDC_PTCR, params->mask->pdc_disable);
 385
 386         prtd->pdc_xpr_save  = at91_ssc_read(params->ssc_base + params->pdc->xpr);
 387         prtd->pdc_xcr_save  = at91_ssc_read(params->ssc_base + params->pdc->xcr);
 388         prtd->pdc_xnpr_save = at91_ssc_read(params->ssc_base + params->pdc->xnpr);
 389         prtd->pdc_xncr_save = at91_ssc_read(params->ssc_base + params->pdc->xncr);
 390
 391         return 0;
 392 }
 393
 394 static int at91_pcm_resume(struct platform_device *pdev,
 395         struct snd_soc_cpu_dai *dai)
 396 {
 397         struct snd_pcm_runtime *runtime = dai->runtime;
 398         struct at91_runtime_data *prtd;
 399         struct at91_pcm_dma_params *params;
 400
 401         if (!runtime)
 402                 return 0;
 403
 404         prtd = runtime->private_data;
 405         params = prtd->params;
 406
 407         /* restore the PDC registers and enable the PDC */
 408         at91_ssc_write(params->ssc_base + params->pdc->xpr,  prtd->pdc_xpr_save);
 409         at91_ssc_write(params->ssc_base + params->pdc->xcr,  prtd->pdc_xcr_save);
 410         at91_ssc_write(params->ssc_base + params->pdc->xnpr, prtd->pdc_xnpr_save);
 411         at91_ssc_write(params->ssc_base + params->pdc->xncr, prtd->pdc_xncr_save);
 412
 413         at91_ssc_write(params->ssc_base + ATMEL_PDC_PTCR, params->mask->pdc_enable);
 414         return 0;
 415 }
 416 #else
 417 #define at91_pcm_suspend        NULL
 418 #define at91_pcm_resume         NULL
 419 #endif
 420
 421 struct snd_soc_platform at91_soc_platform = {
 422         .name           = "at91-audio",
 423         .pcm_ops        = &at91_pcm_ops,
 424         .pcm_new        = at91_pcm_new,
 425         .pcm_free       = at91_pcm_free_dma_buffers,
 426         .suspend        = at91_pcm_suspend,
 427         .resume         = at91_pcm_resume,
 428 };
 429
 430 EXPORT_SYMBOL_GPL(at91_soc_platform);
 431
 432 MODULE_AUTHOR("Frank Mandarino <fmandarino@endrelia.com>");
 433 MODULE_DESCRIPTION("Atmel AT91 PCM module");
 434 MODULE_LICENSE("GPL");