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, prtd->period_ptr);
 107                 at91_ssc_write(params->ssc_base + params->pdc->xncr,
 108                                 prtd->period_size / params->pdc_xfer_size);
 109         }
 110
 111         snd_pcm_period_elapsed(substream);
 112 }
 113
 114 static int at91_pcm_hw_params(struct snd_pcm_substream *substream,
 115         struct snd_pcm_hw_params *params)
 116 {
 117         struct snd_pcm_runtime *runtime = substream->runtime;
 118         struct at91_runtime_data *prtd = runtime->private_data;
 119         struct snd_soc_pcm_runtime *rtd = substream->private_data;
 120
 121         /* this may get called several times by oss emulation
 122          * with different params */
 123
 124         snd_pcm_set_runtime_buffer(substream, &substream->dma_buffer);
 125         runtime->dma_bytes = params_buffer_bytes(params);
 126
 127         prtd->params = rtd->dai->cpu_dai->dma_data;
 128         prtd->params->dma_intr_handler = at91_pcm_dma_irq;
 129
 130         prtd->dma_buffer = runtime->dma_addr;
 131         prtd->dma_buffer_end = runtime->dma_addr + runtime->dma_bytes;
 132         prtd->period_size = params_period_bytes(params);
 133
 134         DBG("hw_params: DMA for %s initialized (dma_bytes=%d, period_size=%d)\n",
 135                 prtd->params->name, runtime->dma_bytes, prtd->period_size);
 136         return 0;
 137 }
 138
 139 static int at91_pcm_hw_free(struct snd_pcm_substream *substream)
 140 {
 141         struct at91_runtime_data *prtd = substream->runtime->private_data;
 142         struct at91_pcm_dma_params *params = prtd->params;
 143
 144         if (params != NULL) {
 145                 at91_ssc_write(params->ssc_base + ATMEL_PDC_PTCR, params->mask->pdc_disable);
 146                 prtd->params->dma_intr_handler = NULL;
 147         }
 148
 149         return 0;
 150 }
 151
 152 static int at91_pcm_prepare(struct snd_pcm_substream *substream)
 153 {
 154         struct at91_runtime_data *prtd = substream->runtime->private_data;
 155         struct at91_pcm_dma_params *params = prtd->params;
 156
 157         at91_ssc_write(params->ssc_base + AT91_SSC_IDR,
 158                         params->mask->ssc_endx | params->mask->ssc_endbuf);
 159
 160         at91_ssc_write(params->ssc_base + ATMEL_PDC_PTCR, params->mask->pdc_disable);
 161         return 0;
 162 }
 163
 164 static int at91_pcm_trigger(struct snd_pcm_substream *substream,
 165         int cmd)
 166 {
 167         struct at91_runtime_data *prtd = substream->runtime->private_data;
 168         struct at91_pcm_dma_params *params = prtd->params;
 169         int ret = 0;
 170
 171         switch (cmd) {
 172         case SNDRV_PCM_TRIGGER_START:
 173                 prtd->period_ptr = prtd->dma_buffer;
 174
 175                 at91_ssc_write(params->ssc_base + params->pdc->xpr, prtd->period_ptr);
 176                 at91_ssc_write(params->ssc_base + params->pdc->xcr,
 177                                 prtd->period_size / params->pdc_xfer_size);
 178
 179                 prtd->period_ptr += prtd->period_size;
 180                 at91_ssc_write(params->ssc_base + params->pdc->xnpr, prtd->period_ptr);
 181                 at91_ssc_write(params->ssc_base + params->pdc->xncr,
 182                                 prtd->period_size / params->pdc_xfer_size);
 183
 184                 DBG("trigger: period_ptr=%lx, xpr=%lx, xcr=%ld, xnpr=%lx, xncr=%ld\n",
 185                         (unsigned long) prtd->period_ptr,
 186                         at91_ssc_read(params->ssc_base + params->pdc->xpr),
 187                         at91_ssc_read(params->ssc_base + params->pdc->xcr),
 188                         at91_ssc_read(params->ssc_base + params->pdc->xnpr),
 189                         at91_ssc_read(params->ssc_base + params->pdc->xncr));
 190
 191                 at91_ssc_write(params->ssc_base + AT91_SSC_IER,
 192                         params->mask->ssc_endx | params->mask->ssc_endbuf);
 193
 194                 at91_ssc_write(params->ssc_base + ATMEL_PDC_PTCR, params->mask->pdc_enable);
 195
 196                 DBG("sr=%lx imr=%lx\n", at91_ssc_read(params->ssc_base + AT91_SSC_SR),
 197                                         at91_ssc_read(params->ssc_base + AT91_SSC_IER));
 198                 break;
 199
 200         case SNDRV_PCM_TRIGGER_STOP:
 201         case SNDRV_PCM_TRIGGER_SUSPEND:
 202         case SNDRV_PCM_TRIGGER_PAUSE_PUSH:
 203                 at91_ssc_write(params->ssc_base + ATMEL_PDC_PTCR, params->mask->pdc_disable);
 204                 break;
 205
 206         case SNDRV_PCM_TRIGGER_RESUME:
 207         case SNDRV_PCM_TRIGGER_PAUSE_RELEASE:
 208                 at91_ssc_write(params->ssc_base + ATMEL_PDC_PTCR, params->mask->pdc_enable);
 209                 break;
 210
 211         default:
 212                 ret = -EINVAL;
 213         }
 214
 215         return ret;
 216 }
 217
 218 static snd_pcm_uframes_t at91_pcm_pointer(
 219         struct snd_pcm_substream *substream)
 220 {
 221         struct snd_pcm_runtime *runtime = substream->runtime;
 222         struct at91_runtime_data *prtd = runtime->private_data;
 223         struct at91_pcm_dma_params *params = prtd->params;
 224         dma_addr_t ptr;
 225         snd_pcm_uframes_t x;
 226
 227         ptr = (dma_addr_t) at91_ssc_read(params->ssc_base + params->pdc->xpr);
 228         x = bytes_to_frames(runtime, ptr - prtd->dma_buffer);
 229
 230         if (x == runtime->buffer_size)
 231                 x = 0;
 232         return x;
 233 }
 234
 235 static int at91_pcm_open(struct snd_pcm_substream *substream)
 236 {
 237         struct snd_pcm_runtime *runtime = substream->runtime;
 238         struct at91_runtime_data *prtd;
 239         int ret = 0;
 240
 241         snd_soc_set_runtime_hwparams(substream, &at91_pcm_hardware);
 242
 243         /* ensure that buffer size is a multiple of period size */
 244         ret = snd_pcm_hw_constraint_integer(runtime, SNDRV_PCM_HW_PARAM_PERIODS);
 245         if (ret < 0)
 246                 goto out;
 247
 248         prtd = kzalloc(sizeof(struct at91_runtime_data), GFP_KERNEL);
 249         if (prtd == NULL) {
 250                 ret = -ENOMEM;
 251                 goto out;
 252         }
 253         runtime->private_data = prtd;
 254
 255  out:
 256         return ret;
 257 }
 258
 259 static int at91_pcm_close(struct snd_pcm_substream *substream)
 260 {
 261         struct at91_runtime_data *prtd = substream->runtime->private_data;
 262
 263         kfree(prtd);
 264         return 0;
 265 }
 266
 267 static int at91_pcm_mmap(struct snd_pcm_substream *substream,
 268         struct vm_area_struct *vma)
 269 {
 270         struct snd_pcm_runtime *runtime = substream->runtime;
 271
 272         return dma_mmap_writecombine(substream->pcm->card->dev, vma,
 273                                      runtime->dma_area,
 274                                      runtime->dma_addr,
 275                                      runtime->dma_bytes);
 276 }
 277
 278 struct snd_pcm_ops at91_pcm_ops = {
 279         .open           = at91_pcm_open,
 280         .close          = at91_pcm_close,
 281         .ioctl          = snd_pcm_lib_ioctl,
 282         .hw_params      = at91_pcm_hw_params,
 283         .hw_free        = at91_pcm_hw_free,
 284         .prepare        = at91_pcm_prepare,
 285         .trigger        = at91_pcm_trigger,
 286         .pointer        = at91_pcm_pointer,
 287         .mmap           = at91_pcm_mmap,
 288 };
 289
 290 static int at91_pcm_preallocate_dma_buffer(struct snd_pcm *pcm,
 291         int stream)
 292 {
 293         struct snd_pcm_substream *substream = pcm->streams[stream].substream;
 294         struct snd_dma_buffer *buf = &substream->dma_buffer;
 295         size_t size = at91_pcm_hardware.buffer_bytes_max;
 296
 297         buf->dev.type = SNDRV_DMA_TYPE_DEV;
 298         buf->dev.dev = pcm->card->dev;
 299         buf->private_data = NULL;
 300         buf->area = dma_alloc_writecombine(pcm->card->dev, size,
 301                                            &buf->addr, GFP_KERNEL);
 302
 303         DBG("preallocate_dma_buffer: area=%p, addr=%p, size=%d\n",
 304                 (void *) buf->area,
 305                 (void *) buf->addr,
 306                 size);
 307
 308         if (!buf->area)
 309                 return -ENOMEM;
 310
 311         buf->bytes = size;
 312         return 0;
 313 }
 314
 315 static u64 at91_pcm_dmamask = 0xffffffff;
 316
 317 static int at91_pcm_new(struct snd_card *card,
 318         struct snd_soc_codec_dai *dai, struct snd_pcm *pcm)
 319 {
 320         int ret = 0;
 321
 322         if (!card->dev->dma_mask)
 323                 card->dev->dma_mask = &at91_pcm_dmamask;
 324         if (!card->dev->coherent_dma_mask)
 325                 card->dev->coherent_dma_mask = 0xffffffff;
 326
 327         if (dai->playback.channels_min) {
 328                 ret = at91_pcm_preallocate_dma_buffer(pcm,
 329                         SNDRV_PCM_STREAM_PLAYBACK);
 330                 if (ret)
 331                         goto out;
 332         }
 333
 334         if (dai->capture.channels_min) {
 335                 ret = at91_pcm_preallocate_dma_buffer(pcm,
 336                         SNDRV_PCM_STREAM_CAPTURE);
 337                 if (ret)
 338                         goto out;
 339         }
 340  out:
 341         return ret;
 342 }
 343
 344 static void at91_pcm_free_dma_buffers(struct snd_pcm *pcm)
 345 {
 346         struct snd_pcm_substream *substream;
 347         struct snd_dma_buffer *buf;
 348         int stream;
 349
 350         for (stream = 0; stream < 2; stream++) {
 351                 substream = pcm->streams[stream].substream;
 352                 if (!substream)
 353                         continue;
 354
 355                 buf = &substream->dma_buffer;
 356                 if (!buf->area)
 357                         continue;
 358
 359                 dma_free_writecombine(pcm->card->dev, buf->bytes,
 360                                       buf->area, buf->addr);
 361                 buf->area = NULL;
 362         }
 363 }
 364
 365 #ifdef CONFIG_PM
 366 static int at91_pcm_suspend(struct platform_device *pdev,
 367         struct snd_soc_cpu_dai *dai)
 368 {
 369         struct snd_pcm_runtime *runtime = dai->runtime;
 370         struct at91_runtime_data *prtd;
 371         struct at91_pcm_dma_params *params;
 372
 373         if (!runtime)
 374                 return 0;
 375
 376         prtd = runtime->private_data;
 377         params = prtd->params;
 378
 379         /* disable the PDC and save the PDC registers */
 380
 381         at91_ssc_write(params->ssc_base + ATMEL_PDC_PTCR, params->mask->pdc_disable);
 382
 383         prtd->pdc_xpr_save  = at91_ssc_read(params->ssc_base + params->pdc->xpr);
 384         prtd->pdc_xcr_save  = at91_ssc_read(params->ssc_base + params->pdc->xcr);
 385         prtd->pdc_xnpr_save = at91_ssc_read(params->ssc_base + params->pdc->xnpr);
 386         prtd->pdc_xncr_save = at91_ssc_read(params->ssc_base + params->pdc->xncr);
 387
 388         return 0;
 389 }
 390
 391 static int at91_pcm_resume(struct platform_device *pdev,
 392         struct snd_soc_cpu_dai *dai)
 393 {
 394         struct snd_pcm_runtime *runtime = dai->runtime;
 395         struct at91_runtime_data *prtd;
 396         struct at91_pcm_dma_params *params;
 397
 398         if (!runtime)
 399                 return 0;
 400
 401         prtd = runtime->private_data;
 402         params = prtd->params;
 403
 404         /* restore the PDC registers and enable the PDC */
 405         at91_ssc_write(params->ssc_base + params->pdc->xpr,  prtd->pdc_xpr_save);
 406         at91_ssc_write(params->ssc_base + params->pdc->xcr,  prtd->pdc_xcr_save);
 407         at91_ssc_write(params->ssc_base + params->pdc->xnpr, prtd->pdc_xnpr_save);
 408         at91_ssc_write(params->ssc_base + params->pdc->xncr, prtd->pdc_xncr_save);
 409
 410         at91_ssc_write(params->ssc_base + ATMEL_PDC_PTCR, params->mask->pdc_enable);
 411         return 0;
 412 }
 413 #else
 414 #define at91_pcm_suspend        NULL
 415 #define at91_pcm_resume         NULL
 416 #endif
 417
 418 struct snd_soc_platform at91_soc_platform = {
 419         .name           = "at91-audio",
 420         .pcm_ops        = &at91_pcm_ops,
 421         .pcm_new        = at91_pcm_new,
 422         .pcm_free       = at91_pcm_free_dma_buffers,
 423         .suspend        = at91_pcm_suspend,
 424         .resume         = at91_pcm_resume,
 425 };
 426
 427 EXPORT_SYMBOL_GPL(at91_soc_platform);
 428
 429 MODULE_AUTHOR("Frank Mandarino <fmandarino@endrelia.com>");
 430 MODULE_DESCRIPTION("Atmel AT91 PCM module");
 431 MODULE_LICENSE("GPL");