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| author | Dimitris Papastamos <dp@opensource.wolfsonmicro.com> | 2012-06-15 16:35:28 +0100 |
|---|---|---|
| committer | Takashi Iwai <tiwai@suse.de> | 2012-06-18 09:38:58 +0200 |
| commit | 4be77a530be1ea62574f31c20dd9848e7e2ab0f6 (patch) | |
| tree | 2e7fa7c283039b028e1136702f7254fede8acf1e | |
| parent | 989b01385fa3cc4eaa488068a0868ae4de5198a9 (diff) | |
| download | linux-4be77a530be1ea62574f31c20dd9848e7e2ab0f6.tar.bz2 | |
ALSA: pcm: Add snd_pcm_rate_bit_to_rate()
This is essentially the reverse of snd_pcm_rate_to_rate_bit().
This is generally useful as the Compress API uses the rate bit
directly and it helps to be able to map back to the actual sample
rate.
Signed-off-by: Dimitris Papastamos <dp@opensource.wolfsonmicro.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
| -rw-r--r-- | include/sound/pcm.h | 1 | ||||
| -rw-r--r-- | sound/core/pcm_misc.c | 18 |
2 files changed, 19 insertions, 0 deletions
diff --git a/include/sound/pcm.h b/include/sound/pcm.h index 0d1112815be3..68372bc1e11b 100644 --- a/include/sound/pcm.h +++ b/include/sound/pcm.h @@ -893,6 +893,7 @@ extern const struct snd_pcm_hw_constraint_list snd_pcm_known_rates; int snd_pcm_limit_hw_rates(struct snd_pcm_runtime *runtime); unsigned int snd_pcm_rate_to_rate_bit(unsigned int rate); +unsigned int snd_pcm_rate_bit_to_rate(unsigned int rate_bit); static inline void snd_pcm_set_runtime_buffer(struct snd_pcm_substream *substream, struct snd_dma_buffer *bufp) diff --git a/sound/core/pcm_misc.c b/sound/core/pcm_misc.c index 9c9eff9afbac..d4fc1bfbe457 100644 --- a/sound/core/pcm_misc.c +++ b/sound/core/pcm_misc.c @@ -488,3 +488,21 @@ unsigned int snd_pcm_rate_to_rate_bit(unsigned int rate) return SNDRV_PCM_RATE_KNOT; } EXPORT_SYMBOL(snd_pcm_rate_to_rate_bit); + +/** + * snd_pcm_rate_bit_to_rate - converts SNDRV_PCM_RATE_xxx bit to sample rate + * @rate_bit: the rate bit to convert + * + * Returns the sample rate that corresponds to the given SNDRV_PCM_RATE_xxx flag + * or 0 for an unknown rate bit + */ +unsigned int snd_pcm_rate_bit_to_rate(unsigned int rate_bit) +{ + unsigned int i; + + for (i = 0; i < snd_pcm_known_rates.count; i++) + if ((1u << i) == rate_bit) + return snd_pcm_known_rates.list[i]; + return 0; +} +EXPORT_SYMBOL(snd_pcm_rate_bit_to_rate); |