From 3bdff244a2bcbde37ec33bf3cdde4638049c6c38 Mon Sep 17 00:00:00 2001 From: Mengdong Lin Date: Fri, 15 Jan 2016 16:13:10 +0800 Subject: 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 Acked-by: Takashi Iwai Acked-by: Liam Girdwood Signed-off-by: Mark Brown --- sound/core/pcm_misc.c | 30 ++++++++++++++++++++++++++++++ 1 file changed, 30 insertions(+) (limited to 'sound/core') 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); -- cgit v1.2.3