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