kernel/sound/soc/atmel/atmel-pcm-pdc.c

   1 /*
   2  * atmel-pcm.c  --  ALSA PCM interface for the Atmel atmel SoC.
   3  *
   4  *  Copyright (C) 2005 SAN People
   5  *  Copyright (C) 2008 Atmel
   6  *
   7  * Authors: Sedji Gaouaou <sedji.gaouaou@atmel.com>
   8  *
   9  * Based on at91-pcm. by:
  10  * Frank Mandarino <fmandarino@endrelia.com>
  11  * Copyright 2006 Endrelia Technologies Inc.
  12  *
  13  * Based on pxa2xx-pcm.c by:
  14  *
  15  * Author:      Nicolas Pitre
  16  * Created:     Nov 30, 2004
  17  * Copyright:   (C) 2004 MontaVista Software, Inc.
  18  *
  19  * This program is free software; you can redistribute it and/or modify
  20  * it under the terms of the GNU General Public License as published by
  21  * the Free Software Foundation; either version 2 of the License, or
  22  * (at your option) any later version.
  23  *
  24  * This program is distributed in the hope that it will be useful,
  25  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  26  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  27  * GNU General Public License for more details.
  28  *
  29  * You should have received a copy of the GNU General Public License
  30  * along with this program; if not, write to the Free Software
  31  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  32  */
  33
  34 #include <linux/module.h>
  35 #include <linux/init.h>
  36 #include <linux/platform_device.h>
  37 #include <linux/slab.h>
  38 #include <linux/dma-mapping.h>
  39 #include <linux/atmel_pdc.h>
  40 #include <linux/atmel-ssc.h>
  41
  42 #include <sound/core.h>
  43 #include <sound/pcm.h>
  44 #include <sound/pcm_params.h>
  45 #include <sound/soc.h>
  46
  47 #include "atmel-pcm.h"
  48
  49
  50 static int atmel_pcm_preallocate_dma_buffer(struct snd_pcm *pcm,
  51         int stream)
  52 {
  53         struct snd_pcm_substream *substream = pcm->streams[stream].substream;
  54         struct snd_dma_buffer *buf = &substream->dma_buffer;
  55         size_t size = ATMEL_SSC_DMABUF_SIZE;
  56
  57         buf->dev.type = SNDRV_DMA_TYPE_DEV;
  58         buf->dev.dev = pcm->card->dev;
  59         buf->private_data = NULL;
  60         buf->area = dma_alloc_coherent(pcm->card->dev, size,
  61                         &buf->addr, GFP_KERNEL);
  62         pr_debug("atmel-pcm: alloc dma buffer: area=%p, addr=%p, size=%zu\n",
  63                         (void *)buf->area, (void *)(long)buf->addr, size);
  64
  65         if (!buf->area)
  66                 return -ENOMEM;
  67
  68         buf->bytes = size;
  69         return 0;
  70 }
  71
  72 static int atmel_pcm_mmap(struct snd_pcm_substream *substream,
  73         struct vm_area_struct *vma)
  74 {
  75         return remap_pfn_range(vma, vma->vm_start,
  76                        substream->dma_buffer.addr >> PAGE_SHIFT,
  77                        vma->vm_end - vma->vm_start, vma->vm_page_prot);
  78 }
  79
  80 static int atmel_pcm_new(struct snd_soc_pcm_runtime *rtd)
  81 {
  82         struct snd_card *card = rtd->card->snd_card;
  83         struct snd_pcm *pcm = rtd->pcm;
  84         int ret;
  85
  86         ret = dma_coerce_mask_and_coherent(card->dev, DMA_BIT_MASK(32));
  87         if (ret)
  88                 return ret;
  89
  90         if (pcm->streams[SNDRV_PCM_STREAM_PLAYBACK].substream) {
  91                 pr_debug("atmel-pcm: allocating PCM playback DMA buffer\n");
  92                 ret = atmel_pcm_preallocate_dma_buffer(pcm,
  93                         SNDRV_PCM_STREAM_PLAYBACK);
  94                 if (ret)
  95                         goto out;
  96         }
  97
  98         if (pcm->streams[SNDRV_PCM_STREAM_CAPTURE].substream) {
  99                 pr_debug("atmel-pcm: allocating PCM capture DMA buffer\n");
 100                 ret = atmel_pcm_preallocate_dma_buffer(pcm,
 101                         SNDRV_PCM_STREAM_CAPTURE);
 102                 if (ret)
 103                         goto out;
 104         }
 105  out:
 106         return ret;
 107 }
 108
 109 static void atmel_pcm_free(struct snd_pcm *pcm)
 110 {
 111         struct snd_pcm_substream *substream;
 112         struct snd_dma_buffer *buf;
 113         int stream;
 114
 115         for (stream = 0; stream < 2; stream++) {
 116                 substream = pcm->streams[stream].substream;
 117                 if (!substream)
 118                         continue;
 119
 120                 buf = &substream->dma_buffer;
 121                 if (!buf->area)
 122                         continue;
 123                 dma_free_coherent(pcm->card->dev, buf->bytes,
 124                                   buf->area, buf->addr);
 125                 buf->area = NULL;
 126         }
 127 }
 128
 129 /*--------------------------------------------------------------------------*\
 130  * Hardware definition
 131 \*--------------------------------------------------------------------------*/
 132 /* TODO: These values were taken from the AT91 platform driver, check
 133  *       them against real values for AT32
 134  */
 135 static const struct snd_pcm_hardware atmel_pcm_hardware = {
 136         .info                   = SNDRV_PCM_INFO_MMAP |
 137                                   SNDRV_PCM_INFO_MMAP_VALID |
 138                                   SNDRV_PCM_INFO_INTERLEAVED |
 139                                   SNDRV_PCM_INFO_PAUSE,
 140         .period_bytes_min       = 32,
 141         .period_bytes_max       = 8192,
 142         .periods_min            = 2,
 143         .periods_max            = 1024,
 144         .buffer_bytes_max       = ATMEL_SSC_DMABUF_SIZE,
 145 };
 146
 147
 148 /*--------------------------------------------------------------------------*\
 149  * Data types
 150 \*--------------------------------------------------------------------------*/
 151 struct atmel_runtime_data {
 152         struct atmel_pcm_dma_params *params;
 153         dma_addr_t dma_buffer;          /* physical address of dma buffer */
 154         dma_addr_t dma_buffer_end;      /* first address beyond DMA buffer */
 155         size_t period_size;
 156
 157         dma_addr_t period_ptr;          /* physical address of next period */
 158 };
 159
 160 /*--------------------------------------------------------------------------*\
 161  * ISR
 162 \*--------------------------------------------------------------------------*/
 163 static void atmel_pcm_dma_irq(u32 ssc_sr,
 164         struct snd_pcm_substream *substream)
 165 {
 166         struct atmel_runtime_data *prtd = substream->runtime->private_data;
 167         struct atmel_pcm_dma_params *params = prtd->params;
 168         static int count;
 169
 170         count++;
 171
 172         if (ssc_sr & params->mask->ssc_endbuf) {
 173                 pr_warn("atmel-pcm: buffer %s on %s (SSC_SR=%#x, count=%d)\n",
 174                                 substream->stream == SNDRV_PCM_STREAM_PLAYBACK
 175                                 ? "underrun" : "overrun",
 176                                 params->name, ssc_sr, count);
 177
 178                 /* re-start the PDC */
 179                 ssc_writex(params->ssc->regs, ATMEL_PDC_PTCR,
 180                            params->mask->pdc_disable);
 181                 prtd->period_ptr += prtd->period_size;
 182                 if (prtd->period_ptr >= prtd->dma_buffer_end)
 183                         prtd->period_ptr = prtd->dma_buffer;
 184
 185                 ssc_writex(params->ssc->regs, params->pdc->xpr,
 186                            prtd->period_ptr);
 187                 ssc_writex(params->ssc->regs, params->pdc->xcr,
 188                            prtd->period_size / params->pdc_xfer_size);
 189                 ssc_writex(params->ssc->regs, ATMEL_PDC_PTCR,
 190                            params->mask->pdc_enable);
 191         }
 192
 193         if (ssc_sr & params->mask->ssc_endx) {
 194                 /* Load the PDC next pointer and counter registers */
 195                 prtd->period_ptr += prtd->period_size;
 196                 if (prtd->period_ptr >= prtd->dma_buffer_end)
 197                         prtd->period_ptr = prtd->dma_buffer;
 198
 199                 ssc_writex(params->ssc->regs, params->pdc->xnpr,
 200                            prtd->period_ptr);
 201                 ssc_writex(params->ssc->regs, params->pdc->xncr,
 202                            prtd->period_size / params->pdc_xfer_size);
 203         }
 204
 205         snd_pcm_period_elapsed(substream);
 206 }
 207
 208
 209 /*--------------------------------------------------------------------------*\
 210  * PCM operations
 211 \*--------------------------------------------------------------------------*/
 212 static int atmel_pcm_hw_params(struct snd_pcm_substream *substream,
 213         struct snd_pcm_hw_params *params)
 214 {
 215         struct snd_pcm_runtime *runtime = substream->runtime;
 216         struct atmel_runtime_data *prtd = runtime->private_data;
 217         struct snd_soc_pcm_runtime *rtd = substream->private_data;
 218
 219         /* this may get called several times by oss emulation
 220          * with different params */
 221
 222         snd_pcm_set_runtime_buffer(substream, &substream->dma_buffer);
 223         runtime->dma_bytes = params_buffer_bytes(params);
 224
 225         prtd->params = snd_soc_dai_get_dma_data(rtd->cpu_dai, substream);
 226         prtd->params->dma_intr_handler = atmel_pcm_dma_irq;
 227
 228         prtd->dma_buffer = runtime->dma_addr;
 229         prtd->dma_buffer_end = runtime->dma_addr + runtime->dma_bytes;
 230         prtd->period_size = params_period_bytes(params);
 231
 232         pr_debug("atmel-pcm: "
 233                 "hw_params: DMA for %s initialized "
 234                 "(dma_bytes=%zu, period_size=%zu)\n",
 235                 prtd->params->name,
 236                 runtime->dma_bytes,
 237                 prtd->period_size);
 238         return 0;
 239 }
 240
 241 static int atmel_pcm_hw_free(struct snd_pcm_substream *substream)
 242 {
 243         struct atmel_runtime_data *prtd = substream->runtime->private_data;
 244         struct atmel_pcm_dma_params *params = prtd->params;
 245
 246         if (params != NULL) {
 247                 ssc_writex(params->ssc->regs, SSC_PDC_PTCR,
 248                            params->mask->pdc_disable);
 249                 prtd->params->dma_intr_handler = NULL;
 250         }
 251
 252         return 0;
 253 }
 254
 255 static int atmel_pcm_prepare(struct snd_pcm_substream *substream)
 256 {
 257         struct atmel_runtime_data *prtd = substream->runtime->private_data;
 258         struct atmel_pcm_dma_params *params = prtd->params;
 259
 260         ssc_writex(params->ssc->regs, SSC_IDR,
 261                    params->mask->ssc_endx | params->mask->ssc_endbuf);
 262         ssc_writex(params->ssc->regs, ATMEL_PDC_PTCR,
 263                    params->mask->pdc_disable);
 264         return 0;
 265 }
 266
 267 static int atmel_pcm_trigger(struct snd_pcm_substream *substream,
 268         int cmd)
 269 {
 270         struct snd_pcm_runtime *rtd = substream->runtime;
 271         struct atmel_runtime_data *prtd = rtd->private_data;
 272         struct atmel_pcm_dma_params *params = prtd->params;
 273         int ret = 0;
 274
 275         pr_debug("atmel-pcm:buffer_size = %ld,"
 276                 "dma_area = %p, dma_bytes = %zu\n",
 277                 rtd->buffer_size, rtd->dma_area, rtd->dma_bytes);
 278
 279         switch (cmd) {
 280         case SNDRV_PCM_TRIGGER_START:
 281                 prtd->period_ptr = prtd->dma_buffer;
 282
 283                 ssc_writex(params->ssc->regs, params->pdc->xpr,
 284                            prtd->period_ptr);
 285                 ssc_writex(params->ssc->regs, params->pdc->xcr,
 286                            prtd->period_size / params->pdc_xfer_size);
 287
 288                 prtd->period_ptr += prtd->period_size;
 289                 ssc_writex(params->ssc->regs, params->pdc->xnpr,
 290                            prtd->period_ptr);
 291                 ssc_writex(params->ssc->regs, params->pdc->xncr,
 292                            prtd->period_size / params->pdc_xfer_size);
 293
 294                 pr_debug("atmel-pcm: trigger: "
 295                         "period_ptr=%lx, xpr=%u, "
 296                         "xcr=%u, xnpr=%u, xncr=%u\n",
 297                         (unsigned long)prtd->period_ptr,
 298                         ssc_readx(params->ssc->regs, params->pdc->xpr),
 299                         ssc_readx(params->ssc->regs, params->pdc->xcr),
 300                         ssc_readx(params->ssc->regs, params->pdc->xnpr),
 301                         ssc_readx(params->ssc->regs, params->pdc->xncr));
 302
 303                 ssc_writex(params->ssc->regs, SSC_IER,
 304                            params->mask->ssc_endx | params->mask->ssc_endbuf);
 305                 ssc_writex(params->ssc->regs, SSC_PDC_PTCR,
 306                            params->mask->pdc_enable);
 307
 308                 pr_debug("sr=%u imr=%u\n",
 309                         ssc_readx(params->ssc->regs, SSC_SR),
 310                         ssc_readx(params->ssc->regs, SSC_IER));
 311                 break;          /* SNDRV_PCM_TRIGGER_START */
 312
 313         case SNDRV_PCM_TRIGGER_STOP:
 314         case SNDRV_PCM_TRIGGER_SUSPEND:
 315         case SNDRV_PCM_TRIGGER_PAUSE_PUSH:
 316                 ssc_writex(params->ssc->regs, ATMEL_PDC_PTCR,
 317                            params->mask->pdc_disable);
 318                 break;
 319
 320         case SNDRV_PCM_TRIGGER_RESUME:
 321         case SNDRV_PCM_TRIGGER_PAUSE_RELEASE:
 322                 ssc_writex(params->ssc->regs, ATMEL_PDC_PTCR,
 323                            params->mask->pdc_enable);
 324                 break;
 325
 326         default:
 327                 ret = -EINVAL;
 328         }
 329
 330         return ret;
 331 }
 332
 333 static snd_pcm_uframes_t atmel_pcm_pointer(
 334         struct snd_pcm_substream *substream)
 335 {
 336         struct snd_pcm_runtime *runtime = substream->runtime;
 337         struct atmel_runtime_data *prtd = runtime->private_data;
 338         struct atmel_pcm_dma_params *params = prtd->params;
 339         dma_addr_t ptr;
 340         snd_pcm_uframes_t x;
 341
 342         ptr = (dma_addr_t) ssc_readx(params->ssc->regs, params->pdc->xpr);
 343         x = bytes_to_frames(runtime, ptr - prtd->dma_buffer);
 344
 345         if (x == runtime->buffer_size)
 346                 x = 0;
 347
 348         return x;
 349 }
 350
 351 static int atmel_pcm_open(struct snd_pcm_substream *substream)
 352 {
 353         struct snd_pcm_runtime *runtime = substream->runtime;
 354         struct atmel_runtime_data *prtd;
 355         int ret = 0;
 356
 357         snd_soc_set_runtime_hwparams(substream, &atmel_pcm_hardware);
 358
 359         /* ensure that buffer size is a multiple of period size */
 360         ret = snd_pcm_hw_constraint_integer(runtime,
 361                                                 SNDRV_PCM_HW_PARAM_PERIODS);
 362         if (ret < 0)
 363                 goto out;
 364
 365         prtd = kzalloc(sizeof(struct atmel_runtime_data), GFP_KERNEL);
 366         if (prtd == NULL) {
 367                 ret = -ENOMEM;
 368                 goto out;
 369         }
 370         runtime->private_data = prtd;
 371
 372  out:
 373         return ret;
 374 }
 375
 376 static int atmel_pcm_close(struct snd_pcm_substream *substream)
 377 {
 378         struct atmel_runtime_data *prtd = substream->runtime->private_data;
 379
 380         kfree(prtd);
 381         return 0;
 382 }
 383
 384 static struct snd_pcm_ops atmel_pcm_ops = {
 385         .open           = atmel_pcm_open,
 386         .close          = atmel_pcm_close,
 387         .ioctl          = snd_pcm_lib_ioctl,
 388         .hw_params      = atmel_pcm_hw_params,
 389         .hw_free        = atmel_pcm_hw_free,
 390         .prepare        = atmel_pcm_prepare,
 391         .trigger        = atmel_pcm_trigger,
 392         .pointer        = atmel_pcm_pointer,
 393         .mmap           = atmel_pcm_mmap,
 394 };
 395
 396 static struct snd_soc_platform_driver atmel_soc_platform = {
 397         .ops            = &atmel_pcm_ops,
 398         .pcm_new        = atmel_pcm_new,
 399         .pcm_free       = atmel_pcm_free,
 400 };
 401
 402 int atmel_pcm_pdc_platform_register(struct device *dev)
 403 {
 404         return snd_soc_register_platform(dev, &atmel_soc_platform);
 405 }
 406 EXPORT_SYMBOL(atmel_pcm_pdc_platform_register);
 407
 408 void atmel_pcm_pdc_platform_unregister(struct device *dev)
 409 {
 410         snd_soc_unregister_platform(dev);
 411 }
 412 EXPORT_SYMBOL(atmel_pcm_pdc_platform_unregister);
 413
 414 MODULE_AUTHOR("Sedji Gaouaou <sedji.gaouaou@atmel.com>");
 415 MODULE_DESCRIPTION("Atmel PCM module");
 416 MODULE_LICENSE("GPL");