linux/sound/arm/pxa2xx-pcm.c
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   1/*
   2 * linux/sound/arm/pxa2xx-pcm.c -- ALSA PCM interface for the Intel PXA2xx chip
   3 *
   4 * Author:      Nicolas Pitre
   5 * Created:     Nov 30, 2004
   6 * Copyright:   (C) 2004 MontaVista Software, Inc.
   7 *
   8 * This program is free software; you can redistribute it and/or modify
   9 * it under the terms of the GNU General Public License version 2 as
  10 * published by the Free Software Foundation.
  11 */
  12
  13#include <linux/module.h>
  14#include <linux/init.h>
  15#include <linux/device.h>
  16#include <linux/slab.h>
  17#include <linux/dma-mapping.h>
  18
  19#include <sound/core.h>
  20#include <sound/pcm.h>
  21#include <sound/pcm_params.h>
  22
  23#include <asm/dma.h>
  24#include <mach/hardware.h>
  25#include <mach/pxa-regs.h>
  26
  27#include "pxa2xx-pcm.h"
  28
  29
  30static const struct snd_pcm_hardware pxa2xx_pcm_hardware = {
  31        .info                   = SNDRV_PCM_INFO_MMAP |
  32                                  SNDRV_PCM_INFO_MMAP_VALID |
  33                                  SNDRV_PCM_INFO_INTERLEAVED |
  34                                  SNDRV_PCM_INFO_PAUSE,
  35        .formats                = SNDRV_PCM_FMTBIT_S16_LE,
  36        .period_bytes_min       = 32,
  37        .period_bytes_max       = 8192 - 32,
  38        .periods_min            = 1,
  39        .periods_max            = PAGE_SIZE/sizeof(pxa_dma_desc),
  40        .buffer_bytes_max       = 128 * 1024,
  41        .fifo_size              = 32,
  42};
  43
  44struct pxa2xx_runtime_data {
  45        int dma_ch;
  46        struct pxa2xx_pcm_dma_params *params;
  47        pxa_dma_desc *dma_desc_array;
  48        dma_addr_t dma_desc_array_phys;
  49};
  50
  51static int pxa2xx_pcm_hw_params(struct snd_pcm_substream *substream,
  52                                struct snd_pcm_hw_params *params)
  53{
  54        struct snd_pcm_runtime *runtime = substream->runtime;
  55        struct pxa2xx_runtime_data *rtd = runtime->private_data;
  56        size_t totsize = params_buffer_bytes(params);
  57        size_t period = params_period_bytes(params);
  58        pxa_dma_desc *dma_desc;
  59        dma_addr_t dma_buff_phys, next_desc_phys;
  60
  61        snd_pcm_set_runtime_buffer(substream, &substream->dma_buffer);
  62        runtime->dma_bytes = totsize;
  63
  64        dma_desc = rtd->dma_desc_array;
  65        next_desc_phys = rtd->dma_desc_array_phys;
  66        dma_buff_phys = runtime->dma_addr;
  67        do {
  68                next_desc_phys += sizeof(pxa_dma_desc);
  69                dma_desc->ddadr = next_desc_phys;
  70                if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) {
  71                        dma_desc->dsadr = dma_buff_phys;
  72                        dma_desc->dtadr = rtd->params->dev_addr;
  73                } else {
  74                        dma_desc->dsadr = rtd->params->dev_addr;
  75                        dma_desc->dtadr = dma_buff_phys;
  76                }
  77                if (period > totsize)
  78                        period = totsize;
  79                dma_desc->dcmd = rtd->params->dcmd | period | DCMD_ENDIRQEN;
  80                dma_desc++;
  81                dma_buff_phys += period;
  82        } while (totsize -= period);
  83        dma_desc[-1].ddadr = rtd->dma_desc_array_phys;
  84
  85        return 0;
  86}
  87
  88static int pxa2xx_pcm_hw_free(struct snd_pcm_substream *substream)
  89{
  90        struct pxa2xx_runtime_data *rtd = substream->runtime->private_data;
  91
  92        *rtd->params->drcmr = 0;
  93        snd_pcm_set_runtime_buffer(substream, NULL);
  94        return 0;
  95}
  96
  97static int pxa2xx_pcm_prepare(struct snd_pcm_substream *substream)
  98{
  99        struct pxa2xx_pcm_client *client = substream->private_data;
 100        struct snd_pcm_runtime *runtime = substream->runtime;
 101        struct pxa2xx_runtime_data *rtd = runtime->private_data;
 102
 103        DCSR(rtd->dma_ch) &= ~DCSR_RUN;
 104        DCSR(rtd->dma_ch) = 0;
 105        DCMD(rtd->dma_ch) = 0;
 106        *rtd->params->drcmr = rtd->dma_ch | DRCMR_MAPVLD;
 107
 108        return client->prepare(substream);
 109}
 110
 111static int pxa2xx_pcm_trigger(struct snd_pcm_substream *substream, int cmd)
 112{
 113        struct pxa2xx_runtime_data *rtd = substream->runtime->private_data;
 114        int ret = 0;
 115
 116        switch (cmd) {
 117        case SNDRV_PCM_TRIGGER_START:
 118                DDADR(rtd->dma_ch) = rtd->dma_desc_array_phys;
 119                DCSR(rtd->dma_ch) = DCSR_RUN;
 120                break;
 121
 122        case SNDRV_PCM_TRIGGER_STOP:
 123        case SNDRV_PCM_TRIGGER_SUSPEND:
 124        case SNDRV_PCM_TRIGGER_PAUSE_PUSH:
 125                DCSR(rtd->dma_ch) &= ~DCSR_RUN;
 126                break;
 127
 128        case SNDRV_PCM_TRIGGER_PAUSE_RELEASE:
 129                DCSR(rtd->dma_ch) |= DCSR_RUN;
 130                break;
 131
 132        default:
 133                ret = -EINVAL;
 134        }
 135
 136        return ret;
 137}
 138
 139static void pxa2xx_pcm_dma_irq(int dma_ch, void *dev_id)
 140{
 141        struct snd_pcm_substream *substream = dev_id;
 142        struct pxa2xx_runtime_data *rtd = substream->runtime->private_data;
 143        int dcsr;
 144
 145        dcsr = DCSR(dma_ch);
 146        DCSR(dma_ch) = dcsr & ~DCSR_STOPIRQEN;
 147
 148        if (dcsr & DCSR_ENDINTR) {
 149                snd_pcm_period_elapsed(substream);
 150        } else {
 151                printk( KERN_ERR "%s: DMA error on channel %d (DCSR=%#x)\n",
 152                        rtd->params->name, dma_ch, dcsr );
 153                snd_pcm_stop(substream, SNDRV_PCM_STATE_XRUN);
 154        }
 155}
 156
 157static snd_pcm_uframes_t pxa2xx_pcm_pointer(struct snd_pcm_substream *substream)
 158{
 159        struct snd_pcm_runtime *runtime = substream->runtime;
 160        struct pxa2xx_runtime_data *rtd = runtime->private_data;
 161        dma_addr_t ptr = (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) ?
 162                         DSADR(rtd->dma_ch) : DTADR(rtd->dma_ch);
 163        snd_pcm_uframes_t x = bytes_to_frames(runtime, ptr - runtime->dma_addr);
 164        if (x == runtime->buffer_size)
 165                x = 0;
 166        return x;
 167}
 168
 169static int
 170pxa2xx_pcm_hw_rule_mult32(struct snd_pcm_hw_params *params, struct snd_pcm_hw_rule *rule)
 171{
 172        struct snd_interval *i = hw_param_interval(params, rule->var);
 173        int changed = 0;
 174
 175        if (i->min & 31) {
 176                i->min = (i->min & ~31) + 32;
 177                i->openmin = 0;
 178                changed = 1;
 179        }
 180
 181        if (i->max & 31) {
 182                i->max &= ~31;
 183                i->openmax = 0;
 184                changed = 1;
 185        }
 186
 187        return changed;
 188}
 189
 190static int pxa2xx_pcm_open(struct snd_pcm_substream *substream)
 191{
 192        struct pxa2xx_pcm_client *client = substream->private_data;
 193        struct snd_pcm_runtime *runtime = substream->runtime;
 194        struct pxa2xx_runtime_data *rtd;
 195        int ret;
 196
 197        runtime->hw = pxa2xx_pcm_hardware;
 198
 199        /*
 200         * For mysterious reasons (and despite what the manual says)
 201         * playback samples are lost if the DMA count is not a multiple
 202         * of the DMA burst size.  Let's add a rule to enforce that.
 203         */
 204        ret = snd_pcm_hw_rule_add(runtime, 0, SNDRV_PCM_HW_PARAM_PERIOD_BYTES,
 205                                  pxa2xx_pcm_hw_rule_mult32, NULL,
 206                                  SNDRV_PCM_HW_PARAM_PERIOD_BYTES, -1);
 207        if (ret)
 208                goto out;
 209        ret = snd_pcm_hw_rule_add(runtime, 0, SNDRV_PCM_HW_PARAM_BUFFER_BYTES,
 210                                  pxa2xx_pcm_hw_rule_mult32, NULL,
 211                                  SNDRV_PCM_HW_PARAM_BUFFER_BYTES, -1);
 212        if (ret)
 213                goto out;
 214
 215        ret = -ENOMEM;
 216        rtd = kmalloc(sizeof(*rtd), GFP_KERNEL);
 217        if (!rtd)
 218                goto out;
 219        rtd->dma_desc_array =
 220                dma_alloc_writecombine(substream->pcm->card->dev, PAGE_SIZE,
 221                                       &rtd->dma_desc_array_phys, GFP_KERNEL);
 222        if (!rtd->dma_desc_array)
 223                goto err1;
 224
 225        rtd->params = (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) ?
 226                      client->playback_params : client->capture_params;
 227        ret = pxa_request_dma(rtd->params->name, DMA_PRIO_LOW,
 228                              pxa2xx_pcm_dma_irq, substream);
 229        if (ret < 0)
 230                goto err2;
 231        rtd->dma_ch = ret;
 232
 233        runtime->private_data = rtd;
 234        ret = client->startup(substream);
 235        if (!ret)
 236                goto out;
 237
 238        pxa_free_dma(rtd->dma_ch);
 239 err2:
 240        dma_free_writecombine(substream->pcm->card->dev, PAGE_SIZE,
 241                              rtd->dma_desc_array, rtd->dma_desc_array_phys);
 242 err1:
 243        kfree(rtd);
 244 out:
 245        return ret;
 246}
 247
 248static int pxa2xx_pcm_close(struct snd_pcm_substream *substream)
 249{
 250        struct pxa2xx_pcm_client *client = substream->private_data;
 251        struct pxa2xx_runtime_data *rtd = substream->runtime->private_data;
 252
 253        pxa_free_dma(rtd->dma_ch);
 254        client->shutdown(substream);
 255        dma_free_writecombine(substream->pcm->card->dev, PAGE_SIZE,
 256                              rtd->dma_desc_array, rtd->dma_desc_array_phys);
 257        kfree(rtd);
 258        return 0;
 259}
 260
 261static int
 262pxa2xx_pcm_mmap(struct snd_pcm_substream *substream, struct vm_area_struct *vma)
 263{
 264        struct snd_pcm_runtime *runtime = substream->runtime;
 265        return dma_mmap_writecombine(substream->pcm->card->dev, vma,
 266                                     runtime->dma_area,
 267                                     runtime->dma_addr,
 268                                     runtime->dma_bytes);
 269}
 270
 271static struct snd_pcm_ops pxa2xx_pcm_ops = {
 272        .open           = pxa2xx_pcm_open,
 273        .close          = pxa2xx_pcm_close,
 274        .ioctl          = snd_pcm_lib_ioctl,
 275        .hw_params      = pxa2xx_pcm_hw_params,
 276        .hw_free        = pxa2xx_pcm_hw_free,
 277        .prepare        = pxa2xx_pcm_prepare,
 278        .trigger        = pxa2xx_pcm_trigger,
 279        .pointer        = pxa2xx_pcm_pointer,
 280        .mmap           = pxa2xx_pcm_mmap,
 281};
 282
 283static int pxa2xx_pcm_preallocate_dma_buffer(struct snd_pcm *pcm, int stream)
 284{
 285        struct snd_pcm_substream *substream = pcm->streams[stream].substream;
 286        struct snd_dma_buffer *buf = &substream->dma_buffer;
 287        size_t size = pxa2xx_pcm_hardware.buffer_bytes_max;
 288        buf->dev.type = SNDRV_DMA_TYPE_DEV;
 289        buf->dev.dev = pcm->card->dev;
 290        buf->private_data = NULL;
 291        buf->area = dma_alloc_writecombine(pcm->card->dev, size,
 292                                           &buf->addr, GFP_KERNEL);
 293        if (!buf->area)
 294                return -ENOMEM;
 295        buf->bytes = size;
 296        return 0;
 297}
 298
 299static void pxa2xx_pcm_free_dma_buffers(struct snd_pcm *pcm)
 300{
 301        struct snd_pcm_substream *substream;
 302        struct snd_dma_buffer *buf;
 303        int stream;
 304
 305        for (stream = 0; stream < 2; stream++) {
 306                substream = pcm->streams[stream].substream;
 307                if (!substream)
 308                        continue;
 309                buf = &substream->dma_buffer;
 310                if (!buf->area)
 311                        continue;
 312                dma_free_writecombine(pcm->card->dev, buf->bytes,
 313                                      buf->area, buf->addr);
 314                buf->area = NULL;
 315        }
 316}
 317
 318static u64 pxa2xx_pcm_dmamask = 0xffffffff;
 319
 320int pxa2xx_pcm_new(struct snd_card *card, struct pxa2xx_pcm_client *client,
 321                   struct snd_pcm **rpcm)
 322{
 323        struct snd_pcm *pcm;
 324        int play = client->playback_params ? 1 : 0;
 325        int capt = client->capture_params ? 1 : 0;
 326        int ret;
 327
 328        ret = snd_pcm_new(card, "PXA2xx-PCM", 0, play, capt, &pcm);
 329        if (ret)
 330                goto out;
 331
 332        pcm->private_data = client;
 333        pcm->private_free = pxa2xx_pcm_free_dma_buffers;
 334
 335        if (!card->dev->dma_mask)
 336                card->dev->dma_mask = &pxa2xx_pcm_dmamask;
 337        if (!card->dev->coherent_dma_mask)
 338                card->dev->coherent_dma_mask = 0xffffffff;
 339
 340        if (play) {
 341                int stream = SNDRV_PCM_STREAM_PLAYBACK;
 342                snd_pcm_set_ops(pcm, stream, &pxa2xx_pcm_ops);
 343                ret = pxa2xx_pcm_preallocate_dma_buffer(pcm, stream);
 344                if (ret)
 345                        goto out;
 346        }
 347        if (capt) {
 348                int stream = SNDRV_PCM_STREAM_CAPTURE;
 349                snd_pcm_set_ops(pcm, stream, &pxa2xx_pcm_ops);
 350                ret = pxa2xx_pcm_preallocate_dma_buffer(pcm, stream);
 351                if (ret)
 352                        goto out;
 353        }
 354
 355        if (rpcm)
 356                *rpcm = pcm;
 357        ret = 0;
 358
 359 out:
 360        return ret;
 361}
 362
 363EXPORT_SYMBOL(pxa2xx_pcm_new);
 364
 365MODULE_AUTHOR("Nicolas Pitre");
 366MODULE_DESCRIPTION("Intel PXA2xx PCM DMA module");
 367MODULE_LICENSE("GPL");
 368