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         return regmap_write(codec->control_data, reg, value);
  27 }
  28
  29 static unsigned int hw_read(struct snd_soc_codec *codec, unsigned int reg)
  30 {
  31         int ret;
  32         unsigned int val;
  33
  34         ret = regmap_read(codec->control_data, reg, &val);
  35         if (ret == 0)
  36                 return val;
  37         else
  38                 return -1;
  39 }
  40
  41 /**
  42  * snd_soc_codec_set_cache_io: Set up standard I/O functions.
  43  *
  44  * @codec: CODEC to configure.
  45  * @map: Register map to write to
  46  *
  47  * Register formats are frequently shared between many I2C and SPI
  48  * devices.  In order to promote code reuse the ASoC core provides
  49  * some standard implementations of CODEC read and write operations
  50  * which can be set up using this function.
  51  *
  52  * The caller is responsible for allocating and initialising the
  53  * actual cache.
  54  *
  55  * Note that at present this code cannot be used by CODECs with
  56  * volatile registers.
  57  */
  58 int snd_soc_codec_set_cache_io(struct snd_soc_codec *codec,
  59                                struct regmap *regmap)
  60 {
  61         int ret;
  62
  63         /* Device has made its own regmap arrangements */
  64         if (!regmap)
  65                 codec->control_data = dev_get_regmap(codec->dev, NULL);
  66         else
  67                 codec->control_data = regmap;
  68
  69         if (IS_ERR(codec->control_data))
  70                 return PTR_ERR(codec->control_data);
  71
  72         codec->write = hw_write;
  73         codec->read = hw_read;
  74
  75         ret = regmap_get_val_bytes(codec->control_data);
  76         /* Errors are legitimate for non-integer byte
  77          * multiples */
  78         if (ret > 0)
  79                 codec->val_bytes = ret;
  80
  81         codec->using_regmap = true;
  82
  83         return 0;
  84 }
  85 EXPORT_SYMBOL_GPL(snd_soc_codec_set_cache_io);
  86 #else
  87 int snd_soc_codec_set_cache_io(struct snd_soc_codec *codec,
  88                                struct regmap *regmap)
  89 {
  90         return -ENOTSUPP;
  91 }
  92 EXPORT_SYMBOL_GPL(snd_soc_codec_set_cache_io);
  93 #endif