sound/soc/soc-io.c

   1 /*
   2  * soc-io.c  --  ASoC register I/O helpers
   3  *
   4  * Copyright 2009-2011 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 <linux/regmap.h>
  17 #include <linux/export.h>
  18 #include <sound/soc.h>
  19
  20 #include <trace/events/asoc.h>
  21
  22 #ifdef CONFIG_REGMAP
  23 static int hw_write(struct snd_soc_codec *codec, unsigned int reg,
  24                     unsigned int value)
  25 {
  26         int ret;
  27
  28         if (!snd_soc_codec_volatile_register(codec, reg) &&
  29             reg < codec->driver->reg_cache_size &&
  30             !codec->cache_bypass) {
  31                 ret = snd_soc_cache_write(codec, reg, value);
  32                 if (ret < 0)
  33                         return -1;
  34         }
  35
  36         if (codec->cache_only) {
  37                 codec->cache_sync = 1;
  38                 return 0;
  39         }
  40
  41         return regmap_write(codec->control_data, reg, value);
  42 }
  43
  44 static unsigned int hw_read(struct snd_soc_codec *codec, unsigned int reg)
  45 {
  46         int ret;
  47         unsigned int val;
  48
  49         if (reg >= codec->driver->reg_cache_size ||
  50             snd_soc_codec_volatile_register(codec, reg) ||
  51             codec->cache_bypass) {
  52                 if (codec->cache_only)
  53                         return -1;
  54
  55                 ret = regmap_read(codec->control_data, reg, &val);
  56                 if (ret == 0)
  57                         return val;
  58                 else
  59                         return -1;
  60         }
  61
  62         ret = snd_soc_cache_read(codec, reg, &val);
  63         if (ret < 0)
  64                 return -1;
  65         return val;
  66 }
  67
  68 /* Primitive bulk write support for soc-cache.  The data pointed to by
  69  * `data' needs to already be in the form the hardware expects.  Any
  70  * data written through this function will not go through the cache as
  71  * it only handles writing to volatile or out of bounds registers.
  72  *
  73  * This is currently only supported for devices using the regmap API
  74  * wrappers.
  75  */
  76 static int snd_soc_hw_bulk_write_raw(struct snd_soc_codec *codec,
  77                                      unsigned int reg,
  78                                      const void *data, size_t len)
  79 {
  80         /* To ensure that we don't get out of sync with the cache, check
  81          * whether the base register is volatile or if we've directly asked
  82          * to bypass the cache.  Out of bounds registers are considered
  83          * volatile.
  84          */
  85         if (!codec->cache_bypass
  86             && !snd_soc_codec_volatile_register(codec, reg)
  87             && reg < codec->driver->reg_cache_size)
  88                 return -EINVAL;
  89
  90         return regmap_raw_write(codec->control_data, reg, data, len);
  91 }
  92
  93 /**
  94  * snd_soc_codec_set_cache_io: Set up standard I/O functions.
  95  *
  96  * @codec: CODEC to configure.
  97  * @addr_bits: Number of bits of register address data.
  98  * @data_bits: Number of bits of data per register.
  99  * @control: Control bus used.
 100  *
 101  * Register formats are frequently shared between many I2C and SPI
 102  * devices.  In order to promote code reuse the ASoC core provides
 103  * some standard implementations of CODEC read and write operations
 104  * which can be set up using this function.
 105  *
 106  * The caller is responsible for allocating and initialising the
 107  * actual cache.
 108  *
 109  * Note that at present this code cannot be used by CODECs with
 110  * volatile registers.
 111  */
 112 int snd_soc_codec_set_cache_io(struct snd_soc_codec *codec,
 113                                int addr_bits, int data_bits,
 114                                enum snd_soc_control_type control)
 115 {
 116         struct regmap_config config;
 117         int ret;
 118
 119         memset(&config, 0, sizeof(config));
 120         codec->write = hw_write;
 121         codec->read = hw_read;
 122         codec->bulk_write_raw = snd_soc_hw_bulk_write_raw;
 123
 124         config.reg_bits = addr_bits;
 125         config.val_bits = data_bits;
 126
 127         switch (control) {
 128 #if defined(CONFIG_REGMAP_I2C) || defined(CONFIG_REGMAP_I2C_MODULE)
 129         case SND_SOC_I2C:
 130                 codec->control_data = regmap_init_i2c(to_i2c_client(codec->dev),
 131                                                       &config);
 132                 break;
 133 #endif
 134
 135 #if defined(CONFIG_REGMAP_SPI) || defined(CONFIG_REGMAP_SPI_MODULE)
 136         case SND_SOC_SPI:
 137                 codec->control_data = regmap_init_spi(to_spi_device(codec->dev),
 138                                                       &config);
 139                 break;
 140 #endif
 141
 142         case SND_SOC_REGMAP:
 143                 /* Device has made its own regmap arrangements */
 144                 codec->using_regmap = true;
 145                 if (!codec->control_data)
 146                         codec->control_data = dev_get_regmap(codec->dev, NULL);
 147
 148                 if (codec->control_data) {
 149                         ret = regmap_get_val_bytes(codec->control_data);
 150                         /* Errors are legitimate for non-integer byte
 151                          * multiples */
 152                         if (ret > 0)
 153                                 codec->val_bytes = ret;
 154                 }
 155                 break;
 156
 157         default:
 158                 return -EINVAL;
 159         }
 160
 161         return PTR_ERR_OR_ZERO(codec->control_data);
 162 }
 163 EXPORT_SYMBOL_GPL(snd_soc_codec_set_cache_io);
 164 #else
 165 int snd_soc_codec_set_cache_io(struct snd_soc_codec *codec,
 166                                int addr_bits, int data_bits,
 167                                enum snd_soc_control_type control)
 168 {
 169         return -ENOTSUPP;
 170 }
 171 EXPORT_SYMBOL_GPL(snd_soc_codec_set_cache_io);
 172 #endif