diff options
author | Mark Brown <broonie@opensource.wolfsonmicro.com> | 2009-04-14 13:22:37 +0100 |
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committer | Mark Brown <broonie@opensource.wolfsonmicro.com> | 2009-04-14 13:22:37 +0100 |
commit | 6967963d6d5cac40a091d075326f0e3ccb95c58a (patch) | |
tree | a9c29ac6450a7d1dc815f9d97f726ecd59271812 /include/sound/control.h | |
parent | 9b1a88c7105f593cc61a7acd3c51fcf4bf7b8038 (diff) | |
parent | 34e51ce60a210094bd66cf0a75dd8512247618ca (diff) |
Merge branch 'for-2.6.30' into for-2.6.31
Diffstat (limited to 'include/sound/control.h')
-rw-r--r-- | include/sound/control.h | 52 |
1 files changed, 50 insertions, 2 deletions
diff --git a/include/sound/control.h b/include/sound/control.h index 4721b4bba05..ef96f07aa03 100644 --- a/include/sound/control.h +++ b/include/sound/control.h @@ -171,6 +171,54 @@ int snd_ctl_boolean_stereo_info(struct snd_kcontrol *kcontrol, */ struct snd_kcontrol *snd_ctl_make_virtual_master(char *name, const unsigned int *tlv); -int snd_ctl_add_slave(struct snd_kcontrol *master, struct snd_kcontrol *slave); - +int _snd_ctl_add_slave(struct snd_kcontrol *master, struct snd_kcontrol *slave, + unsigned int flags); +/* optional flags for slave */ +#define SND_CTL_SLAVE_NEED_UPDATE (1 << 0) + +/** + * snd_ctl_add_slave - Add a virtual slave control + * @master: vmaster element + * @slave: slave element to add + * + * Add a virtual slave control to the given master element created via + * snd_ctl_create_virtual_master() beforehand. + * Returns zero if successful or a negative error code. + * + * All slaves must be the same type (returning the same information + * via info callback). The fucntion doesn't check it, so it's your + * responsibility. + * + * Also, some additional limitations: + * at most two channels, + * logarithmic volume control (dB level) thus no linear volume, + * master can only attenuate the volume without gain + */ +static inline int +snd_ctl_add_slave(struct snd_kcontrol *master, struct snd_kcontrol *slave) +{ + return _snd_ctl_add_slave(master, slave, 0); +} + +/** + * snd_ctl_add_slave_uncached - Add a virtual slave control + * @master: vmaster element + * @slave: slave element to add + * + * Add a virtual slave control to the given master. + * Unlike snd_ctl_add_slave(), the element added via this function + * is supposed to have volatile values, and get callback is called + * at each time quried from the master. + * + * When the control peeks the hardware values directly and the value + * can be changed by other means than the put callback of the element, + * this function should be used to keep the value always up-to-date. + */ +static inline int +snd_ctl_add_slave_uncached(struct snd_kcontrol *master, + struct snd_kcontrol *slave) +{ + return _snd_ctl_add_slave(master, slave, SND_CTL_SLAVE_NEED_UPDATE); +} + #endif /* __SOUND_CONTROL_H */ |