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authorCharles Keepax <ckeepax@opensource.wolfsonmicro.com>2015-06-25 09:35:12 +0100
committerMark Brown <broonie@kernel.org>2015-07-07 13:15:12 +0100
commit5f8e671a49e1d608fcf52c8944ea7818cd4c99a9 (patch)
tree8802ff671911422dd7866a21d5ebe56b900eac5d /sound/soc/codecs/arizona.c
parentc05d9a8c7f55a901d9e8ec2a5f0730137bbfea4a (diff)
ASoC: arizona: Implement stability check for LHPF coefficients
Specifying unstable coefficients for the low/high pass filters can have a severe impact on the audio. This patchs adds a stability check on the coefficients written to the low/high pass filter block to prevent this. Signed-off-by: Charles Keepax <ckeepax@opensource.wolfsonmicro.com> Signed-off-by: Mark Brown <broonie@kernel.org>
Diffstat (limited to 'sound/soc/codecs/arizona.c')
-rw-r--r--sound/soc/codecs/arizona.c17
1 files changed, 17 insertions, 0 deletions
diff --git a/sound/soc/codecs/arizona.c b/sound/soc/codecs/arizona.c
index 39967863d2ec..a88202d768f4 100644
--- a/sound/soc/codecs/arizona.c
+++ b/sound/soc/codecs/arizona.c
@@ -2372,6 +2372,23 @@ out:
}
EXPORT_SYMBOL_GPL(arizona_eq_coeff_put);
+int arizona_lhpf_coeff_put(struct snd_kcontrol *kcontrol,
+ struct snd_ctl_elem_value *ucontrol)
+{
+ struct snd_soc_codec *codec = snd_soc_kcontrol_codec(kcontrol);
+ struct arizona *arizona = dev_get_drvdata(codec->dev->parent);
+ __be16 *data = (__be16 *)ucontrol->value.bytes.data;
+ s16 val = be16_to_cpu(*data);
+
+ if (abs(val) >= 4096) {
+ dev_err(arizona->dev, "Rejecting unstable LHPF coefficients\n");
+ return -EINVAL;
+ }
+
+ return snd_soc_bytes_put(kcontrol, ucontrol);
+}
+EXPORT_SYMBOL_GPL(arizona_lhpf_coeff_put);
+
MODULE_DESCRIPTION("ASoC Wolfson Arizona class device support");
MODULE_AUTHOR("Mark Brown <broonie@opensource.wolfsonmicro.com>");
MODULE_LICENSE("GPL");