LXR linux/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 */
  56static 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\*--------------------------------------------------------------------------*/
  72struct 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\*--------------------------------------------------------------------------*/
  84static 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\*--------------------------------------------------------------------------*/
 133static 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
 162static 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
 176static 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
 188static 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
 254static 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
 272static 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
 297static 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
 305static 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
 317static 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
 323int atmel_pcm_pdc_platform_register(struct device *dev)
 324{
 325        return snd_soc_register_platform(dev, &atmel_soc_platform);
 326}
 327EXPORT_SYMBOL(atmel_pcm_pdc_platform_register);
 328
 329void atmel_pcm_pdc_platform_unregister(struct device *dev)
 330{
 331        snd_soc_unregister_platform(dev);
 332}
 333EXPORT_SYMBOL(atmel_pcm_pdc_platform_unregister);
 334
 335MODULE_AUTHOR("Sedji Gaouaou <sedji.gaouaou@atmel.com>");
 336MODULE_DESCRIPTION("Atmel PCM module");
 337MODULE_LICENSE("GPL");
 338