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authorMengdong Lin <mengdong.lin@linux.intel.com>2016-01-15 16:13:10 +0800
committerMark Brown <broonie@kernel.org>2016-02-05 18:49:00 +0000
commit3bdff244a2bcbde37ec33bf3cdde4638049c6c38 (patch)
tree303301fb742e1719b42a6c5456a7c167483623b1 /sound/core
parent92e963f50fc74041b5e9e744c330dca48e04f08d (diff)
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>
Diffstat (limited to 'sound/core')
-rw-r--r--sound/core/pcm_misc.c30
1 files changed, 30 insertions, 0 deletions
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);