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 /*--------------------------------------------------------------------------*\
  51  * Hardware definition
  52 \*--------------------------------------------------------------------------*/
  53 /* TODO: These values were taken from the AT91 platform driver, check
  54  *       them against real values for AT32
  55  */
  56 static const struct snd_pcm_hardware atmel_pcm_hardware = {
  57         .info                   = SNDRV_PCM_INFO_MMAP |
  58                                   SNDRV_PCM_INFO_MMAP_VALID |
  59                                   SNDRV_PCM_INFO_INTERLEAVED |
  60                                   SNDRV_PCM_INFO_PAUSE,
  61         .period_bytes_min       = 32,
  62         .period_bytes_max       = 8192,
  63         .periods_min            = 2,
  64         .periods_max            = 1024,
  65         .buffer_bytes_max       = ATMEL_SSC_DMABUF_SIZE,
  66 };
  67
  68
  69 /*--------------------------------------------------------------------------*\
  70  * Data types
  71 \*--------------------------------------------------------------------------*/
  72 struct atmel_runtime_data {
  73         struct atmel_pcm_dma_params *params;
  74         dma_addr_t dma_buffer;          /* physical address of dma buffer */
  75         dma_addr_t dma_buffer_end;      /* first address beyond DMA buffer */
  76         size_t period_size;
  77
  78         dma_addr_t period_ptr;          /* physical address of next period */
  79 };
  80
  81 /*--------------------------------------------------------------------------*\
  82  * ISR
  83 \*--------------------------------------------------------------------------*/
  84 static void atmel_pcm_dma_irq(u32 ssc_sr,
  85         struct snd_pcm_substream *substream)
  86 {
  87         struct atmel_runtime_data *prtd = substream->runtime->private_data;
  88         struct atmel_pcm_dma_params *params = prtd->params;
  89         static int count;
  90
  91         count++;
  92
  93         if (ssc_sr & params->mask->ssc_endbuf) {
  94                 pr_warn("atmel-pcm: buffer %s on %s (SSC_SR=%#x, count=%d)\n",
  95                                 substream->stream == SNDRV_PCM_STREAM_PLAYBACK
  96                                 ? "underrun" : "overrun",
  97                                 params->name, ssc_sr, count);
  98
  99                 /* re-start the PDC */
 100                 ssc_writex(params->ssc->regs, ATMEL_PDC_PTCR,
 101                            params->mask->pdc_disable);
 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                 ssc_writex(params->ssc->regs, params->pdc->xpr,
 107                            prtd->period_ptr);
 108                 ssc_writex(params->ssc->regs, params->pdc->xcr,
 109                            prtd->period_size / params->pdc_xfer_size);
 110                 ssc_writex(params->ssc->regs, ATMEL_PDC_PTCR,
 111                            params->mask->pdc_enable);
 112         }
 113
 114         if (ssc_sr & params->mask->ssc_endx) {
 115                 /* Load the PDC next pointer and counter registers */
 116                 prtd->period_ptr += prtd->period_size;
 117                 if (prtd->period_ptr >= prtd->dma_buffer_end)
 118                         prtd->period_ptr = prtd->dma_buffer;
 119
 120                 ssc_writex(params->ssc->regs, params->pdc->xnpr,
 121                            prtd->period_ptr);
 122                 ssc_writex(params->ssc->regs, params->pdc->xncr,
 123                            prtd->period_size / params->pdc_xfer_size);
 124         }
 125
 126         snd_pcm_period_elapsed(substream);
 127 }
 128
 129
 130 /*--------------------------------------------------------------------------*\
 131  * PCM operations
 132 \*--------------------------------------------------------------------------*/
 133 static int atmel_pcm_hw_params(struct snd_pcm_substream *substream,
 134         struct snd_pcm_hw_params *params)
 135 {
 136         struct snd_pcm_runtime *runtime = substream->runtime;
 137         struct atmel_runtime_data *prtd = runtime->private_data;
 138         struct snd_soc_pcm_runtime *rtd = substream->private_data;
 139
 140         /* this may get called several times by oss emulation
 141          * with different params */
 142
 143         snd_pcm_set_runtime_buffer(substream, &substream->dma_buffer);
 144         runtime->dma_bytes = params_buffer_bytes(params);
 145
 146         prtd->params = snd_soc_dai_get_dma_data(rtd->cpu_dai, substream);
 147         prtd->params->dma_intr_handler = atmel_pcm_dma_irq;
 148
 149         prtd->dma_buffer = runtime->dma_addr;
 150         prtd->dma_buffer_end = runtime->dma_addr + runtime->dma_bytes;
 151         prtd->period_size = params_period_bytes(params);
 152
 153         pr_debug("atmel-pcm: "
 154                 "hw_params: DMA for %s initialized "
 155                 "(dma_bytes=%zu, period_size=%zu)\n",
 156                 prtd->params->name,
 157                 runtime->dma_bytes,
 158                 prtd->period_size);
 159         return 0;
 160 }
 161
 162 static int atmel_pcm_hw_free(struct snd_pcm_substream *substream)
 163 {
 164         struct atmel_runtime_data *prtd = substream->runtime->private_data;
 165         struct atmel_pcm_dma_params *params = prtd->params;
 166
 167         if (params != NULL) {
 168                 ssc_writex(params->ssc->regs, SSC_PDC_PTCR,
 169                            params->mask->pdc_disable);
 170                 prtd->params->dma_intr_handler = NULL;
 171         }
 172
 173         return 0;
 174 }
 175
 176 static int atmel_pcm_prepare(struct snd_pcm_substream *substream)
 177 {
 178         struct atmel_runtime_data *prtd = substream->runtime->private_data;
 179         struct atmel_pcm_dma_params *params = prtd->params;
 180
 181         ssc_writex(params->ssc->regs, SSC_IDR,
 182                    params->mask->ssc_endx | params->mask->ssc_endbuf);
 183         ssc_writex(params->ssc->regs, ATMEL_PDC_PTCR,
 184                    params->mask->pdc_disable);
 185         return 0;
 186 }
 187
 188 static int atmel_pcm_trigger(struct snd_pcm_substream *substream,
 189         int cmd)
 190 {
 191         struct snd_pcm_runtime *rtd = substream->runtime;
 192         struct atmel_runtime_data *prtd = rtd->private_data;
 193         struct atmel_pcm_dma_params *params = prtd->params;
 194         int ret = 0;
 195
 196         pr_debug("atmel-pcm:buffer_size = %ld,"
 197                 "dma_area = %p, dma_bytes = %zu\n",
 198                 rtd->buffer_size, rtd->dma_area, rtd->dma_bytes);
 199
 200         switch (cmd) {
 201         case SNDRV_PCM_TRIGGER_START:
 202                 prtd->period_ptr = prtd->dma_buffer;
 203
 204                 ssc_writex(params->ssc->regs, params->pdc->xpr,
 205                            prtd->period_ptr);
 206                 ssc_writex(params->ssc->regs, params->pdc->xcr,
 207                            prtd->period_size / params->pdc_xfer_size);
 208
 209                 prtd->period_ptr += prtd->period_size;
 210                 ssc_writex(params->ssc->regs, params->pdc->xnpr,
 211                            prtd->period_ptr);
 212                 ssc_writex(params->ssc->regs, params->pdc->xncr,
 213                            prtd->period_size / params->pdc_xfer_size);
 214
 215                 pr_debug("atmel-pcm: trigger: "
 216                         "period_ptr=%lx, xpr=%u, "
 217                         "xcr=%u, xnpr=%u, xncr=%u\n",
 218                         (unsigned long)prtd->period_ptr,
 219                         ssc_readx(params->ssc->regs, params->pdc->xpr),
 220                         ssc_readx(params->ssc->regs, params->pdc->xcr),
 221                         ssc_readx(params->ssc->regs, params->pdc->xnpr),
 222                         ssc_readx(params->ssc->regs, params->pdc->xncr));
 223
 224                 ssc_writex(params->ssc->regs, SSC_IER,
 225                            params->mask->ssc_endx | params->mask->ssc_endbuf);
 226                 ssc_writex(params->ssc->regs, SSC_PDC_PTCR,
 227                            params->mask->pdc_enable);
 228
 229                 pr_debug("sr=%u imr=%u\n",
 230                         ssc_readx(params->ssc->regs, SSC_SR),
 231                         ssc_readx(params->ssc->regs, SSC_IER));
 232                 break;          /* SNDRV_PCM_TRIGGER_START */
 233
 234         case SNDRV_PCM_TRIGGER_STOP:
 235         case SNDRV_PCM_TRIGGER_SUSPEND:
 236         case SNDRV_PCM_TRIGGER_PAUSE_PUSH:
 237                 ssc_writex(params->ssc->regs, ATMEL_PDC_PTCR,
 238                            params->mask->pdc_disable);
 239                 break;
 240
 241         case SNDRV_PCM_TRIGGER_RESUME:
 242         case SNDRV_PCM_TRIGGER_PAUSE_RELEASE:
 243                 ssc_writex(params->ssc->regs, ATMEL_PDC_PTCR,
 244                            params->mask->pdc_enable);
 245                 break;
 246
 247         default:
 248                 ret = -EINVAL;
 249         }
 250
 251         return ret;
 252 }
 253
 254 static snd_pcm_uframes_t atmel_pcm_pointer(
 255         struct snd_pcm_substream *substream)
 256 {
 257         struct snd_pcm_runtime *runtime = substream->runtime;
 258         struct atmel_runtime_data *prtd = runtime->private_data;
 259         struct atmel_pcm_dma_params *params = prtd->params;
 260         dma_addr_t ptr;
 261         snd_pcm_uframes_t x;
 262
 263         ptr = (dma_addr_t) ssc_readx(params->ssc->regs, params->pdc->xpr);
 264         x = bytes_to_frames(runtime, ptr - prtd->dma_buffer);
 265
 266         if (x == runtime->buffer_size)
 267                 x = 0;
 268
 269         return x;
 270 }
 271
 272 static int atmel_pcm_open(struct snd_pcm_substream *substream)
 273 {
 274         struct snd_pcm_runtime *runtime = substream->runtime;
 275         struct atmel_runtime_data *prtd;
 276         int ret = 0;
 277
 278         snd_soc_set_runtime_hwparams(substream, &atmel_pcm_hardware);
 279
 280         /* ensure that buffer size is a multiple of period size */
 281         ret = snd_pcm_hw_constraint_integer(runtime,
 282                                                 SNDRV_PCM_HW_PARAM_PERIODS);
 283         if (ret < 0)
 284                 goto out;
 285
 286         prtd = kzalloc(sizeof(struct atmel_runtime_data), GFP_KERNEL);
 287         if (prtd == NULL) {
 288                 ret = -ENOMEM;
 289                 goto out;
 290         }
 291         runtime->private_data = prtd;
 292
 293  out:
 294         return ret;
 295 }
 296
 297 static int atmel_pcm_close(struct snd_pcm_substream *substream)
 298 {
 299         struct atmel_runtime_data *prtd = substream->runtime->private_data;
 300
 301         kfree(prtd);
 302         return 0;
 303 }
 304
 305 static struct snd_pcm_ops atmel_pcm_ops = {
 306         .open           = atmel_pcm_open,
 307         .close          = atmel_pcm_close,
 308         .ioctl          = snd_pcm_lib_ioctl,
 309         .hw_params      = atmel_pcm_hw_params,
 310         .hw_free        = atmel_pcm_hw_free,
 311         .prepare        = atmel_pcm_prepare,
 312         .trigger        = atmel_pcm_trigger,
 313         .pointer        = atmel_pcm_pointer,
 314         .mmap           = atmel_pcm_mmap,
 315 };
 316
 317 static struct snd_soc_platform_driver atmel_soc_platform = {
 318         .ops            = &atmel_pcm_ops,
 319         .pcm_new        = atmel_pcm_new,
 320         .pcm_free       = atmel_pcm_free,
 321 };
 322
 323 int atmel_pcm_pdc_platform_register(struct device *dev)
 324 {
 325         return snd_soc_register_platform(dev, &atmel_soc_platform);
 326 }
 327 EXPORT_SYMBOL(atmel_pcm_pdc_platform_register);
 328
 329 void atmel_pcm_pdc_platform_unregister(struct device *dev)
 330 {
 331         snd_soc_unregister_platform(dev);
 332 }
 333 EXPORT_SYMBOL(atmel_pcm_pdc_platform_unregister);
 334
 335 MODULE_AUTHOR("Sedji Gaouaou <sedji.gaouaou@atmel.com>");
 336 MODULE_DESCRIPTION("Atmel PCM module");
 337 MODULE_LICENSE("GPL");