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| author | Clemens Ladisch <clemens@ladisch.de> | 2011-09-16 23:03:02 +0200 |
|---|---|---|
| committer | Takashi Iwai <tiwai@suse.de> | 2011-09-20 08:56:45 +0200 |
| commit | d5b702a64b4c273c8eed7e4e721364493d01fdc9 (patch) | |
| tree | a2bdccd13ad840c8f71f848e3f4d096839a322df /sound/core | |
| parent | 84f9df159df6311f33ab16637772788cf3729ede (diff) | |
| download | linux-d5b702a64b4c273c8eed7e4e721364493d01fdc9.tar.gz linux-d5b702a64b4c273c8eed7e4e721364493d01fdc9.tar.bz2 linux-d5b702a64b4c273c8eed7e4e721364493d01fdc9.zip | |
ALSA: pcm: add snd_pcm_hw_rule_noresample()
Add a helper function to allow drivers to disable hardware resampling
when the application has specified the SNDRV_PCM_HW_PARAMS_NORESAMPLE
flag.
Signed-off-by: Clemens Ladisch <clemens@ladisch.de>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Diffstat (limited to 'sound/core')
| -rw-r--r-- | sound/core/pcm_lib.c | 26 |
1 files changed, 26 insertions, 0 deletions
diff --git a/sound/core/pcm_lib.c b/sound/core/pcm_lib.c index 62e90b862a0d..95d1e789715f 100644 --- a/sound/core/pcm_lib.c +++ b/sound/core/pcm_lib.c @@ -1399,6 +1399,32 @@ int snd_pcm_hw_constraint_pow2(struct snd_pcm_runtime *runtime, EXPORT_SYMBOL(snd_pcm_hw_constraint_pow2); +static int snd_pcm_hw_rule_noresample_func(struct snd_pcm_hw_params *params, + struct snd_pcm_hw_rule *rule) +{ + unsigned int base_rate = (unsigned int)(uintptr_t)rule->private; + struct snd_interval *rate; + + rate = hw_param_interval(params, SNDRV_PCM_HW_PARAM_RATE); + return snd_interval_list(rate, 1, &base_rate, 0); +} + +/** + * snd_pcm_hw_rule_noresample - add a rule to allow disabling hw resampling + * @runtime: PCM runtime instance + * @base_rate: the rate at which the hardware does not resample + */ +int snd_pcm_hw_rule_noresample(struct snd_pcm_runtime *runtime, + unsigned int base_rate) +{ + return snd_pcm_hw_rule_add(runtime, SNDRV_PCM_HW_PARAMS_NORESAMPLE, + SNDRV_PCM_HW_PARAM_RATE, + snd_pcm_hw_rule_noresample_func, + (void *)(uintptr_t)base_rate, + SNDRV_PCM_HW_PARAM_RATE, -1); +} +EXPORT_SYMBOL(snd_pcm_hw_rule_noresample); + static void _snd_pcm_hw_param_any(struct snd_pcm_hw_params *params, snd_pcm_hw_param_t var) { |