linux/sound/soc/soc-cache.c
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   1/*
   2 * soc-cache.c  --  ASoC register cache helpers
   3 *
   4 * Copyright 2009 Wolfson Microelectronics PLC.
   5 *
   6 * Author: Mark Brown <broonie@opensource.wolfsonmicro.com>
   7 *
   8 *  This program is free software; you can redistribute  it and/or modify it
   9 *  under  the terms of  the GNU General  Public License as published by the
  10 *  Free Software Foundation;  either version 2 of the  License, or (at your
  11 *  option) any later version.
  12 */
  13
  14#include <linux/i2c.h>
  15#include <linux/spi/spi.h>
  16#include <sound/soc.h>
  17#include <linux/bitmap.h>
  18#include <linux/rbtree.h>
  19#include <linux/export.h>
  20
  21#include <trace/events/asoc.h>
  22
  23static bool snd_soc_set_cache_val(void *base, unsigned int idx,
  24                                  unsigned int val, unsigned int word_size)
  25{
  26        switch (word_size) {
  27        case 1: {
  28                u8 *cache = base;
  29                if (cache[idx] == val)
  30                        return true;
  31                cache[idx] = val;
  32                break;
  33        }
  34        case 2: {
  35                u16 *cache = base;
  36                if (cache[idx] == val)
  37                        return true;
  38                cache[idx] = val;
  39                break;
  40        }
  41        default:
  42                BUG();
  43        }
  44        return false;
  45}
  46
  47static unsigned int snd_soc_get_cache_val(const void *base, unsigned int idx,
  48                unsigned int word_size)
  49{
  50        if (!base)
  51                return -1;
  52
  53        switch (word_size) {
  54        case 1: {
  55                const u8 *cache = base;
  56                return cache[idx];
  57        }
  58        case 2: {
  59                const u16 *cache = base;
  60                return cache[idx];
  61        }
  62        default:
  63                BUG();
  64        }
  65        /* unreachable */
  66        return -1;
  67}
  68
  69static int snd_soc_flat_cache_sync(struct snd_soc_codec *codec)
  70{
  71        int i;
  72        int ret;
  73        const struct snd_soc_codec_driver *codec_drv;
  74        unsigned int val;
  75
  76        codec_drv = codec->driver;
  77        for (i = 0; i < codec_drv->reg_cache_size; ++i) {
  78                ret = snd_soc_cache_read(codec, i, &val);
  79                if (ret)
  80                        return ret;
  81                if (codec->reg_def_copy)
  82                        if (snd_soc_get_cache_val(codec->reg_def_copy,
  83                                                  i, codec_drv->reg_word_size) == val)
  84                                continue;
  85
  86                WARN_ON(!snd_soc_codec_writable_register(codec, i));
  87
  88                ret = snd_soc_write(codec, i, val);
  89                if (ret)
  90                        return ret;
  91                dev_dbg(codec->dev, "ASoC: Synced register %#x, value = %#x\n",
  92                        i, val);
  93        }
  94        return 0;
  95}
  96
  97static int snd_soc_flat_cache_write(struct snd_soc_codec *codec,
  98                                    unsigned int reg, unsigned int value)
  99{
 100        snd_soc_set_cache_val(codec->reg_cache, reg, value,
 101                              codec->driver->reg_word_size);
 102        return 0;
 103}
 104
 105static int snd_soc_flat_cache_read(struct snd_soc_codec *codec,
 106                                   unsigned int reg, unsigned int *value)
 107{
 108        *value = snd_soc_get_cache_val(codec->reg_cache, reg,
 109                                       codec->driver->reg_word_size);
 110        return 0;
 111}
 112
 113static int snd_soc_flat_cache_exit(struct snd_soc_codec *codec)
 114{
 115        if (!codec->reg_cache)
 116                return 0;
 117        kfree(codec->reg_cache);
 118        codec->reg_cache = NULL;
 119        return 0;
 120}
 121
 122static int snd_soc_flat_cache_init(struct snd_soc_codec *codec)
 123{
 124        if (codec->reg_def_copy)
 125                codec->reg_cache = kmemdup(codec->reg_def_copy,
 126                                           codec->reg_size, GFP_KERNEL);
 127        else
 128                codec->reg_cache = kzalloc(codec->reg_size, GFP_KERNEL);
 129        if (!codec->reg_cache)
 130                return -ENOMEM;
 131
 132        return 0;
 133}
 134
 135/* an array of all supported compression types */
 136static const struct snd_soc_cache_ops cache_types[] = {
 137        /* Flat *must* be the first entry for fallback */
 138        {
 139                .id = SND_SOC_FLAT_COMPRESSION,
 140                .name = "flat",
 141                .init = snd_soc_flat_cache_init,
 142                .exit = snd_soc_flat_cache_exit,
 143                .read = snd_soc_flat_cache_read,
 144                .write = snd_soc_flat_cache_write,
 145                .sync = snd_soc_flat_cache_sync
 146        },
 147};
 148
 149int snd_soc_cache_init(struct snd_soc_codec *codec)
 150{
 151        int i;
 152
 153        for (i = 0; i < ARRAY_SIZE(cache_types); ++i)
 154                if (cache_types[i].id == codec->compress_type)
 155                        break;
 156
 157        /* Fall back to flat compression */
 158        if (i == ARRAY_SIZE(cache_types)) {
 159                dev_warn(codec->dev, "ASoC: Could not match compress type: %d\n",
 160                         codec->compress_type);
 161                i = 0;
 162        }
 163
 164        mutex_init(&codec->cache_rw_mutex);
 165        codec->cache_ops = &cache_types[i];
 166
 167        if (codec->cache_ops->init) {
 168                if (codec->cache_ops->name)
 169                        dev_dbg(codec->dev, "ASoC: Initializing %s cache for %s codec\n",
 170                                codec->cache_ops->name, codec->name);
 171                return codec->cache_ops->init(codec);
 172        }
 173        return -ENOSYS;
 174}
 175
 176/*
 177 * NOTE: keep in mind that this function might be called
 178 * multiple times.
 179 */
 180int snd_soc_cache_exit(struct snd_soc_codec *codec)
 181{
 182        if (codec->cache_ops && codec->cache_ops->exit) {
 183                if (codec->cache_ops->name)
 184                        dev_dbg(codec->dev, "ASoC: Destroying %s cache for %s codec\n",
 185                                codec->cache_ops->name, codec->name);
 186                return codec->cache_ops->exit(codec);
 187        }
 188        return -ENOSYS;
 189}
 190
 191/**
 192 * snd_soc_cache_read: Fetch the value of a given register from the cache.
 193 *
 194 * @codec: CODEC to configure.
 195 * @reg: The register index.
 196 * @value: The value to be returned.
 197 */
 198int snd_soc_cache_read(struct snd_soc_codec *codec,
 199                       unsigned int reg, unsigned int *value)
 200{
 201        int ret;
 202
 203        mutex_lock(&codec->cache_rw_mutex);
 204
 205        if (value && codec->cache_ops && codec->cache_ops->read) {
 206                ret = codec->cache_ops->read(codec, reg, value);
 207                mutex_unlock(&codec->cache_rw_mutex);
 208                return ret;
 209        }
 210
 211        mutex_unlock(&codec->cache_rw_mutex);
 212        return -ENOSYS;
 213}
 214EXPORT_SYMBOL_GPL(snd_soc_cache_read);
 215
 216/**
 217 * snd_soc_cache_write: Set the value of a given register in the cache.
 218 *
 219 * @codec: CODEC to configure.
 220 * @reg: The register index.
 221 * @value: The new register value.
 222 */
 223int snd_soc_cache_write(struct snd_soc_codec *codec,
 224                        unsigned int reg, unsigned int value)
 225{
 226        int ret;
 227
 228        mutex_lock(&codec->cache_rw_mutex);
 229
 230        if (codec->cache_ops && codec->cache_ops->write) {
 231                ret = codec->cache_ops->write(codec, reg, value);
 232                mutex_unlock(&codec->cache_rw_mutex);
 233                return ret;
 234        }
 235
 236        mutex_unlock(&codec->cache_rw_mutex);
 237        return -ENOSYS;
 238}
 239EXPORT_SYMBOL_GPL(snd_soc_cache_write);
 240
 241/**
 242 * snd_soc_cache_sync: Sync the register cache with the hardware.
 243 *
 244 * @codec: CODEC to configure.
 245 *
 246 * Any registers that should not be synced should be marked as
 247 * volatile.  In general drivers can choose not to use the provided
 248 * syncing functionality if they so require.
 249 */
 250int snd_soc_cache_sync(struct snd_soc_codec *codec)
 251{
 252        int ret;
 253        const char *name;
 254
 255        if (!codec->cache_sync) {
 256                return 0;
 257        }
 258
 259        if (!codec->cache_ops || !codec->cache_ops->sync)
 260                return -ENOSYS;
 261
 262        if (codec->cache_ops->name)
 263                name = codec->cache_ops->name;
 264        else
 265                name = "unknown";
 266
 267        if (codec->cache_ops->name)
 268                dev_dbg(codec->dev, "ASoC: Syncing %s cache for %s codec\n",
 269                        codec->cache_ops->name, codec->name);
 270        trace_snd_soc_cache_sync(codec, name, "start");
 271        ret = codec->cache_ops->sync(codec);
 272        if (!ret)
 273                codec->cache_sync = 0;
 274        trace_snd_soc_cache_sync(codec, name, "end");
 275        return ret;
 276}
 277EXPORT_SYMBOL_GPL(snd_soc_cache_sync);
 278
 279static int snd_soc_get_reg_access_index(struct snd_soc_codec *codec,
 280                                        unsigned int reg)
 281{
 282        const struct snd_soc_codec_driver *codec_drv;
 283        unsigned int min, max, index;
 284
 285        codec_drv = codec->driver;
 286        min = 0;
 287        max = codec_drv->reg_access_size - 1;
 288        do {
 289                index = (min + max) / 2;
 290                if (codec_drv->reg_access_default[index].reg == reg)
 291                        return index;
 292                if (codec_drv->reg_access_default[index].reg < reg)
 293                        min = index + 1;
 294                else
 295                        max = index;
 296        } while (min <= max);
 297        return -1;
 298}
 299
 300int snd_soc_default_volatile_register(struct snd_soc_codec *codec,
 301                                      unsigned int reg)
 302{
 303        int index;
 304
 305        if (reg >= codec->driver->reg_cache_size)
 306                return 1;
 307        index = snd_soc_get_reg_access_index(codec, reg);
 308        if (index < 0)
 309                return 0;
 310        return codec->driver->reg_access_default[index].vol;
 311}
 312EXPORT_SYMBOL_GPL(snd_soc_default_volatile_register);
 313
 314int snd_soc_default_readable_register(struct snd_soc_codec *codec,
 315                                      unsigned int reg)
 316{
 317        int index;
 318
 319        if (reg >= codec->driver->reg_cache_size)
 320                return 1;
 321        index = snd_soc_get_reg_access_index(codec, reg);
 322        if (index < 0)
 323                return 0;
 324        return codec->driver->reg_access_default[index].read;
 325}
 326EXPORT_SYMBOL_GPL(snd_soc_default_readable_register);
 327
 328int snd_soc_default_writable_register(struct snd_soc_codec *codec,
 329                                      unsigned int reg)
 330{
 331        int index;
 332
 333        if (reg >= codec->driver->reg_cache_size)
 334                return 1;
 335        index = snd_soc_get_reg_access_index(codec, reg);
 336        if (index < 0)
 337                return 0;
 338        return codec->driver->reg_access_default[index].write;
 339}
 340EXPORT_SYMBOL_GPL(snd_soc_default_writable_register);
 341
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