linux/sound/soc/atmel/atmel-pcm-pdc.c
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   1// SPDX-License-Identifier: GPL-2.0-or-later
   2/*
   3 * atmel-pcm.c  --  ALSA PCM interface for the Atmel atmel SoC.
   4 *
   5 *  Copyright (C) 2005 SAN People
   6 *  Copyright (C) 2008 Atmel
   7 *
   8 * Authors: Sedji Gaouaou <sedji.gaouaou@atmel.com>
   9 *
  10 * Based on at91-pcm. by:
  11 * Frank Mandarino <fmandarino@endrelia.com>
  12 * Copyright 2006 Endrelia Technologies Inc.
  13 *
  14 * Based on pxa2xx-pcm.c by:
  15 *
  16 * Author:      Nicolas Pitre
  17 * Created:     Nov 30, 2004
  18 * Copyright:   (C) 2004 MontaVista Software, Inc.
  19 */
  20
  21#include <linux/module.h>
  22#include <linux/init.h>
  23#include <linux/platform_device.h>
  24#include <linux/slab.h>
  25#include <linux/dma-mapping.h>
  26#include <linux/atmel_pdc.h>
  27#include <linux/atmel-ssc.h>
  28
  29#include <sound/core.h>
  30#include <sound/pcm.h>
  31#include <sound/pcm_params.h>
  32#include <sound/soc.h>
  33
  34#include "atmel-pcm.h"
  35
  36
  37static int atmel_pcm_new(struct snd_soc_component *component,
  38                         struct snd_soc_pcm_runtime *rtd)
  39{
  40        struct snd_card *card = rtd->card->snd_card;
  41        int ret;
  42
  43        ret = dma_coerce_mask_and_coherent(card->dev, DMA_BIT_MASK(32));
  44        if (ret)
  45                return ret;
  46
  47        snd_pcm_set_managed_buffer_all(rtd->pcm, SNDRV_DMA_TYPE_DEV,
  48                                       card->dev, ATMEL_SSC_DMABUF_SIZE,
  49                                       ATMEL_SSC_DMABUF_SIZE);
  50
  51        return 0;
  52}
  53
  54/*--------------------------------------------------------------------------*\
  55 * Hardware definition
  56\*--------------------------------------------------------------------------*/
  57/* TODO: These values were taken from the AT91 platform driver, check
  58 *       them against real values for AT32
  59 */
  60static const struct snd_pcm_hardware atmel_pcm_hardware = {
  61        .info                   = SNDRV_PCM_INFO_MMAP |
  62                                  SNDRV_PCM_INFO_MMAP_VALID |
  63                                  SNDRV_PCM_INFO_INTERLEAVED |
  64                                  SNDRV_PCM_INFO_PAUSE,
  65        .period_bytes_min       = 32,
  66        .period_bytes_max       = 8192,
  67        .periods_min            = 2,
  68        .periods_max            = 1024,
  69        .buffer_bytes_max       = ATMEL_SSC_DMABUF_SIZE,
  70};
  71
  72
  73/*--------------------------------------------------------------------------*\
  74 * Data types
  75\*--------------------------------------------------------------------------*/
  76struct atmel_runtime_data {
  77        struct atmel_pcm_dma_params *params;
  78        dma_addr_t dma_buffer;          /* physical address of dma buffer */
  79        dma_addr_t dma_buffer_end;      /* first address beyond DMA buffer */
  80        size_t period_size;
  81
  82        dma_addr_t period_ptr;          /* physical address of next period */
  83};
  84
  85/*--------------------------------------------------------------------------*\
  86 * ISR
  87\*--------------------------------------------------------------------------*/
  88static void atmel_pcm_dma_irq(u32 ssc_sr,
  89        struct snd_pcm_substream *substream)
  90{
  91        struct atmel_runtime_data *prtd = substream->runtime->private_data;
  92        struct atmel_pcm_dma_params *params = prtd->params;
  93        static int count;
  94
  95        count++;
  96
  97        if (ssc_sr & params->mask->ssc_endbuf) {
  98                pr_warn("atmel-pcm: buffer %s on %s (SSC_SR=%#x, count=%d)\n",
  99                                substream->stream == SNDRV_PCM_STREAM_PLAYBACK
 100                                ? "underrun" : "overrun",
 101                                params->name, ssc_sr, count);
 102
 103                /* re-start the PDC */
 104                ssc_writex(params->ssc->regs, ATMEL_PDC_PTCR,
 105                           params->mask->pdc_disable);
 106                prtd->period_ptr += prtd->period_size;
 107                if (prtd->period_ptr >= prtd->dma_buffer_end)
 108                        prtd->period_ptr = prtd->dma_buffer;
 109
 110                ssc_writex(params->ssc->regs, params->pdc->xpr,
 111                           prtd->period_ptr);
 112                ssc_writex(params->ssc->regs, params->pdc->xcr,
 113                           prtd->period_size / params->pdc_xfer_size);
 114                ssc_writex(params->ssc->regs, ATMEL_PDC_PTCR,
 115                           params->mask->pdc_enable);
 116        }
 117
 118        if (ssc_sr & params->mask->ssc_endx) {
 119                /* Load the PDC next pointer and counter registers */
 120                prtd->period_ptr += prtd->period_size;
 121                if (prtd->period_ptr >= prtd->dma_buffer_end)
 122                        prtd->period_ptr = prtd->dma_buffer;
 123
 124                ssc_writex(params->ssc->regs, params->pdc->xnpr,
 125                           prtd->period_ptr);
 126                ssc_writex(params->ssc->regs, params->pdc->xncr,
 127                           prtd->period_size / params->pdc_xfer_size);
 128        }
 129
 130        snd_pcm_period_elapsed(substream);
 131}
 132
 133
 134/*--------------------------------------------------------------------------*\
 135 * PCM operations
 136\*--------------------------------------------------------------------------*/
 137static int atmel_pcm_hw_params(struct snd_soc_component *component,
 138                               struct snd_pcm_substream *substream,
 139                               struct snd_pcm_hw_params *params)
 140{
 141        struct snd_pcm_runtime *runtime = substream->runtime;
 142        struct atmel_runtime_data *prtd = runtime->private_data;
 143        struct snd_soc_pcm_runtime *rtd = asoc_substream_to_rtd(substream);
 144
 145        /* this may get called several times by oss emulation
 146         * with different params */
 147
 148        prtd->params = snd_soc_dai_get_dma_data(asoc_rtd_to_cpu(rtd, 0), substream);
 149        prtd->params->dma_intr_handler = atmel_pcm_dma_irq;
 150
 151        prtd->dma_buffer = runtime->dma_addr;
 152        prtd->dma_buffer_end = runtime->dma_addr + runtime->dma_bytes;
 153        prtd->period_size = params_period_bytes(params);
 154
 155        pr_debug("atmel-pcm: "
 156                "hw_params: DMA for %s initialized "
 157                "(dma_bytes=%zu, period_size=%zu)\n",
 158                prtd->params->name,
 159                runtime->dma_bytes,
 160                prtd->period_size);
 161        return 0;
 162}
 163
 164static int atmel_pcm_hw_free(struct snd_soc_component *component,
 165                             struct snd_pcm_substream *substream)
 166{
 167        struct atmel_runtime_data *prtd = substream->runtime->private_data;
 168        struct atmel_pcm_dma_params *params = prtd->params;
 169
 170        if (params != NULL) {
 171                ssc_writex(params->ssc->regs, SSC_PDC_PTCR,
 172                           params->mask->pdc_disable);
 173                prtd->params->dma_intr_handler = NULL;
 174        }
 175
 176        return 0;
 177}
 178
 179static int atmel_pcm_prepare(struct snd_soc_component *component,
 180                             struct snd_pcm_substream *substream)
 181{
 182        struct atmel_runtime_data *prtd = substream->runtime->private_data;
 183        struct atmel_pcm_dma_params *params = prtd->params;
 184
 185        ssc_writex(params->ssc->regs, SSC_IDR,
 186                   params->mask->ssc_endx | params->mask->ssc_endbuf);
 187        ssc_writex(params->ssc->regs, ATMEL_PDC_PTCR,
 188                   params->mask->pdc_disable);
 189        return 0;
 190}
 191
 192static int atmel_pcm_trigger(struct snd_soc_component *component,
 193                             struct snd_pcm_substream *substream, int cmd)
 194{
 195        struct snd_pcm_runtime *rtd = substream->runtime;
 196        struct atmel_runtime_data *prtd = rtd->private_data;
 197        struct atmel_pcm_dma_params *params = prtd->params;
 198        int ret = 0;
 199
 200        pr_debug("atmel-pcm:buffer_size = %ld,"
 201                "dma_area = %p, dma_bytes = %zu\n",
 202                rtd->buffer_size, rtd->dma_area, rtd->dma_bytes);
 203
 204        switch (cmd) {
 205        case SNDRV_PCM_TRIGGER_START:
 206                prtd->period_ptr = prtd->dma_buffer;
 207
 208                ssc_writex(params->ssc->regs, params->pdc->xpr,
 209                           prtd->period_ptr);
 210                ssc_writex(params->ssc->regs, params->pdc->xcr,
 211                           prtd->period_size / params->pdc_xfer_size);
 212
 213                prtd->period_ptr += prtd->period_size;
 214                ssc_writex(params->ssc->regs, params->pdc->xnpr,
 215                           prtd->period_ptr);
 216                ssc_writex(params->ssc->regs, params->pdc->xncr,
 217                           prtd->period_size / params->pdc_xfer_size);
 218
 219                pr_debug("atmel-pcm: trigger: "
 220                        "period_ptr=%lx, xpr=%u, "
 221                        "xcr=%u, xnpr=%u, xncr=%u\n",
 222                        (unsigned long)prtd->period_ptr,
 223                        ssc_readx(params->ssc->regs, params->pdc->xpr),
 224                        ssc_readx(params->ssc->regs, params->pdc->xcr),
 225                        ssc_readx(params->ssc->regs, params->pdc->xnpr),
 226                        ssc_readx(params->ssc->regs, params->pdc->xncr));
 227
 228                ssc_writex(params->ssc->regs, SSC_IER,
 229                           params->mask->ssc_endx | params->mask->ssc_endbuf);
 230                ssc_writex(params->ssc->regs, SSC_PDC_PTCR,
 231                           params->mask->pdc_enable);
 232
 233                pr_debug("sr=%u imr=%u\n",
 234                        ssc_readx(params->ssc->regs, SSC_SR),
 235                        ssc_readx(params->ssc->regs, SSC_IER));
 236                break;          /* SNDRV_PCM_TRIGGER_START */
 237
 238        case SNDRV_PCM_TRIGGER_STOP:
 239        case SNDRV_PCM_TRIGGER_SUSPEND:
 240        case SNDRV_PCM_TRIGGER_PAUSE_PUSH:
 241                ssc_writex(params->ssc->regs, ATMEL_PDC_PTCR,
 242                           params->mask->pdc_disable);
 243                break;
 244
 245        case SNDRV_PCM_TRIGGER_RESUME:
 246        case SNDRV_PCM_TRIGGER_PAUSE_RELEASE:
 247                ssc_writex(params->ssc->regs, ATMEL_PDC_PTCR,
 248                           params->mask->pdc_enable);
 249                break;
 250
 251        default:
 252                ret = -EINVAL;
 253        }
 254
 255        return ret;
 256}
 257
 258static snd_pcm_uframes_t atmel_pcm_pointer(struct snd_soc_component *component,
 259                                           struct snd_pcm_substream *substream)
 260{
 261        struct snd_pcm_runtime *runtime = substream->runtime;
 262        struct atmel_runtime_data *prtd = runtime->private_data;
 263        struct atmel_pcm_dma_params *params = prtd->params;
 264        dma_addr_t ptr;
 265        snd_pcm_uframes_t x;
 266
 267        ptr = (dma_addr_t) ssc_readx(params->ssc->regs, params->pdc->xpr);
 268        x = bytes_to_frames(runtime, ptr - prtd->dma_buffer);
 269
 270        if (x == runtime->buffer_size)
 271                x = 0;
 272
 273        return x;
 274}
 275
 276static int atmel_pcm_open(struct snd_soc_component *component,
 277                          struct snd_pcm_substream *substream)
 278{
 279        struct snd_pcm_runtime *runtime = substream->runtime;
 280        struct atmel_runtime_data *prtd;
 281        int ret = 0;
 282
 283        snd_soc_set_runtime_hwparams(substream, &atmel_pcm_hardware);
 284
 285        /* ensure that buffer size is a multiple of period size */
 286        ret = snd_pcm_hw_constraint_integer(runtime,
 287                                                SNDRV_PCM_HW_PARAM_PERIODS);
 288        if (ret < 0)
 289                goto out;
 290
 291        prtd = kzalloc(sizeof(struct atmel_runtime_data), GFP_KERNEL);
 292        if (prtd == NULL) {
 293                ret = -ENOMEM;
 294                goto out;
 295        }
 296        runtime->private_data = prtd;
 297
 298 out:
 299        return ret;
 300}
 301
 302static int atmel_pcm_close(struct snd_soc_component *component,
 303                           struct snd_pcm_substream *substream)
 304{
 305        struct atmel_runtime_data *prtd = substream->runtime->private_data;
 306
 307        kfree(prtd);
 308        return 0;
 309}
 310
 311static const struct snd_soc_component_driver atmel_soc_platform = {
 312        .open           = atmel_pcm_open,
 313        .close          = atmel_pcm_close,
 314        .hw_params      = atmel_pcm_hw_params,
 315        .hw_free        = atmel_pcm_hw_free,
 316        .prepare        = atmel_pcm_prepare,
 317        .trigger        = atmel_pcm_trigger,
 318        .pointer        = atmel_pcm_pointer,
 319        .pcm_construct  = atmel_pcm_new,
 320};
 321
 322int atmel_pcm_pdc_platform_register(struct device *dev)
 323{
 324        return devm_snd_soc_register_component(dev, &atmel_soc_platform,
 325                                               NULL, 0);
 326}
 327EXPORT_SYMBOL(atmel_pcm_pdc_platform_register);
 328
 329MODULE_AUTHOR("Sedji Gaouaou <sedji.gaouaou@atmel.com>");
 330MODULE_DESCRIPTION("Atmel PCM module");
 331MODULE_LICENSE("GPL");
 332