diff options
| author | Mengdong Lin <mengdong.lin@linux.intel.com> | 2016-01-15 11:13:10 +0300 |
|---|---|---|
| committer | Mark Brown <broonie@kernel.org> | 2016-02-05 21:49:00 +0300 |
| commit | 3bdff244a2bcbde37ec33bf3cdde4638049c6c38 (patch) | |
| tree | 303301fb742e1719b42a6c5456a7c167483623b1 | |
| parent | 92e963f50fc74041b5e9e744c330dca48e04f08d (diff) | |
| download | linux-3bdff244a2bcbde37ec33bf3cdde4638049c6c38.tar.xz | |
ALSA: pcm: Add snd_pcm_rate_range_to_bits()
This helper function can convert a given sample rate range to
SNDRV_PCM_RATE_xxx bits.
Signed-off-by: Mengdong Lin <mengdong.lin@linux.intel.com>
Acked-by: Takashi Iwai <tiwai@suse.de>
Acked-by: Liam Girdwood <liam.r.girdwood@linux.intel.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
| -rw-r--r-- | include/sound/pcm.h | 2 | ||||
| -rw-r--r-- | sound/core/pcm_misc.c | 30 |
2 files changed, 32 insertions, 0 deletions
diff --git a/include/sound/pcm.h b/include/sound/pcm.h index b0be09279943..af1fb37c6b26 100644 --- a/include/sound/pcm.h +++ b/include/sound/pcm.h @@ -1093,6 +1093,8 @@ unsigned int snd_pcm_rate_to_rate_bit(unsigned int rate); unsigned int snd_pcm_rate_bit_to_rate(unsigned int rate_bit); unsigned int snd_pcm_rate_mask_intersect(unsigned int rates_a, unsigned int rates_b); +unsigned int snd_pcm_rate_range_to_bits(unsigned int rate_min, + unsigned int rate_max); /** * snd_pcm_set_runtime_buffer - Set the PCM runtime buffer diff --git a/sound/core/pcm_misc.c b/sound/core/pcm_misc.c index ebe8444de6c6..53dc37357bca 100644 --- a/sound/core/pcm_misc.c +++ b/sound/core/pcm_misc.c @@ -565,3 +565,33 @@ unsigned int snd_pcm_rate_mask_intersect(unsigned int rates_a, return rates_a & rates_b; } EXPORT_SYMBOL_GPL(snd_pcm_rate_mask_intersect); + +/** + * snd_pcm_rate_range_to_bits - converts rate range to SNDRV_PCM_RATE_xxx bit + * @rate_min: the minimum sample rate + * @rate_max: the maximum sample rate + * + * This function has an implicit assumption: the rates in the given range have + * only the pre-defined rates like 44100 or 16000. + * + * Return: The SNDRV_PCM_RATE_xxx flag that corresponds to the given rate range, + * or SNDRV_PCM_RATE_KNOT for an unknown range. + */ +unsigned int snd_pcm_rate_range_to_bits(unsigned int rate_min, + unsigned int rate_max) +{ + unsigned int rates = 0; + int i; + + for (i = 0; i < snd_pcm_known_rates.count; i++) { + if (snd_pcm_known_rates.list[i] >= rate_min + && snd_pcm_known_rates.list[i] <= rate_max) + rates |= 1 << i; + } + + if (!rates) + rates = SNDRV_PCM_RATE_KNOT; + + return rates; +} +EXPORT_SYMBOL_GPL(snd_pcm_rate_range_to_bits); |