From: Mengdong Lin mengdong.lin@linux.intel.com
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
diff --git a/include/sound/pcm.h b/include/sound/pcm.h index b0be092..af1fb37 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 ebe8444..53dc373 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);