For common scenarios, device drivers can provide a table of all the registers that are at least either readable/writable/volatile. The idea is that if a register lookup fails, all of its read/write/vol members will be zero and will be treated as default. This also reduces the size of the register access array.
Signed-off-by: Dimitris Papastamos dp@opensource.wolfsonmicro.com --- include/sound/soc.h | 22 ++++++++++++++++++++++ sound/soc/soc-cache.c | 49 +++++++++++++++++++++++++++++++++++++++++++++++++ 2 files changed, 71 insertions(+), 0 deletions(-)
diff --git a/include/sound/soc.h b/include/sound/soc.h index d609232..b8acf99 100644 --- a/include/sound/soc.h +++ b/include/sound/soc.h @@ -276,6 +276,10 @@ int snd_soc_cache_write(struct snd_soc_codec *codec, unsigned int reg, unsigned int value); int snd_soc_cache_read(struct snd_soc_codec *codec, unsigned int reg, unsigned int *value); +int snd_soc_default_volatile_register(struct snd_soc_codec *codec, + unsigned int reg); +int snd_soc_default_readable_register(struct snd_soc_codec *codec, + unsigned int reg);
/* Utility functions to get clock rates from various things */ int snd_soc_calc_frame_size(int sample_size, int channels, int tdm_slots); @@ -367,6 +371,22 @@ int snd_soc_put_volsw_2r_sx(struct snd_kcontrol *kcontrol, struct snd_ctl_elem_value *ucontrol);
/** + * struct snd_soc_reg_access - Describes whether a given register is + * readable, writable or volatile. + * + * @reg: the register number + * @read: whether this register is readable + * @write: whether this register is writable + * @vol: whether this register is volatile + */ +struct snd_soc_reg_access { + u16 reg; + u16 read; + u16 write; + u16 vol; +}; + +/** * struct snd_soc_jack_pin - Describes a pin to update based on jack detection * * @pin: name of the pin to update @@ -515,6 +535,8 @@ struct snd_soc_codec_driver { short reg_cache_step; short reg_word_size; const void *reg_cache_default; + short reg_access_size; + const struct snd_soc_reg_access *reg_access_default; enum snd_soc_compress_type compress_type;
/* codec bias level */ diff --git a/sound/soc/soc-cache.c b/sound/soc/soc-cache.c index 1a36b36..d97a59f 100644 --- a/sound/soc/soc-cache.c +++ b/sound/soc/soc-cache.c @@ -1603,3 +1603,52 @@ int snd_soc_cache_sync(struct snd_soc_codec *codec) return -EINVAL; } EXPORT_SYMBOL_GPL(snd_soc_cache_sync); + +static int snd_soc_get_reg_access_index(struct snd_soc_codec *codec, + unsigned int reg) +{ + const struct snd_soc_codec_driver *codec_drv; + unsigned int min, max, index; + + codec_drv = codec->driver; + min = 0; + max = codec_drv->reg_access_size - 1; + do { + index = (min + max) / 2; + if (codec_drv->reg_access_default[index].reg == reg) + return index; + if (codec_drv->reg_access_default[index].reg < reg) + min = index + 1; + else + max = index; + } while (min <= max); + return -1; +} + +int snd_soc_default_volatile_register(struct snd_soc_codec *codec, + unsigned int reg) +{ + int index; + + if (reg >= codec->driver->reg_cache_size) + return 1; + index = snd_soc_get_reg_access_index(codec, reg); + if (index < 0) + return 0; + return codec->driver->reg_access_default[index].vol; +} +EXPORT_SYMBOL_GPL(snd_soc_default_volatile_register); + +int snd_soc_default_readable_register(struct snd_soc_codec *codec, + unsigned int reg) +{ + int index; + + if (reg >= codec->driver->reg_cache_size) + return 1; + index = snd_soc_get_reg_access_index(codec, reg); + if (index < 0) + return 0; + return codec->driver->reg_access_default[index].read; +} +EXPORT_SYMBOL_GPL(snd_soc_default_readable_register);