ASoC: Automatically manage WM8731 deemphasis
The deemphasis filter should be selected based on sample rate for
optimal performance.
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Acked-by: Liam Girdwood <lrg@slimlogic.co.uk>
diff --git a/sound/soc/codecs/wm8731.c b/sound/soc/codecs/wm8731.c
index 8003761..71122dc 100644
--- a/sound/soc/codecs/wm8731.c
+++ b/sound/soc/codecs/wm8731.c
@@ -46,6 +46,8 @@
u16 reg_cache[WM8731_CACHEREGNUM];
unsigned int sysclk;
int sysclk_type;
+ int playback_fs;
+ bool deemph;
};
@@ -65,14 +67,73 @@
static const char *wm8731_input_select[] = {"Line In", "Mic"};
-static const char *wm8731_deemph[] = {"None", "32Khz", "44.1Khz", "48Khz"};
-
static const struct soc_enum wm8731_insel_enum =
SOC_ENUM_SINGLE(WM8731_APANA, 2, 2, wm8731_input_select);
-static const struct soc_enum wm8731_deemph_enum =
- SOC_ENUM_SINGLE(WM8731_APDIGI, 1, 4, wm8731_deemph);
+static int wm8731_deemph[] = { 0, 32000, 44100, 48000 };
+static int wm8731_set_deemph(struct snd_soc_codec *codec)
+{
+ struct wm8731_priv *wm8731 = snd_soc_codec_get_drvdata(codec);
+ int val, i, best;
+
+ /* If we're using deemphasis select the nearest available sample
+ * rate.
+ */
+ if (wm8731->deemph) {
+ best = 1;
+ for (i = 2; i < ARRAY_SIZE(wm8731_deemph); i++) {
+ if (abs(wm8731_deemph[i] - wm8731->playback_fs) <
+ abs(wm8731_deemph[best] - wm8731->playback_fs))
+ best = i;
+ }
+
+ val = best << 1;
+ } else {
+ best = 0;
+ val = 0;
+ }
+
+ dev_dbg(codec->dev, "Set deemphasis %d (%dHz)\n",
+ best, wm8731_deemph[best]);
+
+ return snd_soc_update_bits(codec, WM8731_APDIGI, 0x6, val);
+}
+
+static int wm8731_get_deemph(struct snd_kcontrol *kcontrol,
+ struct snd_ctl_elem_value *ucontrol)
+{
+ struct snd_soc_codec *codec = snd_kcontrol_chip(kcontrol);
+ struct wm8731_priv *wm8731 = snd_soc_codec_get_drvdata(codec);
+
+ ucontrol->value.enumerated.item[0] = wm8731->deemph;
+
+ return 0;
+}
+
+static int wm8731_put_deemph(struct snd_kcontrol *kcontrol,
+ struct snd_ctl_elem_value *ucontrol)
+{
+ struct snd_soc_codec *codec = snd_kcontrol_chip(kcontrol);
+ struct wm8731_priv *wm8731 = snd_soc_codec_get_drvdata(codec);
+ int deemph = ucontrol->value.enumerated.item[0];
+ int ret = 0;
+
+ if (deemph > 1)
+ return -EINVAL;
+
+ mutex_lock(&codec->mutex);
+ if (wm8731->deemph != deemph) {
+ wm8731->deemph = deemph;
+
+ wm8731_set_deemph(codec);
+
+ ret = 1;
+ }
+ mutex_unlock(&codec->mutex);
+
+ return ret;
+}
static const DECLARE_TLV_DB_SCALE(in_tlv, -3450, 150, 0);
static const DECLARE_TLV_DB_SCALE(sidetone_tlv, -1500, 300, 0);
@@ -99,7 +160,8 @@
SOC_SINGLE("ADC High Pass Filter Switch", WM8731_APDIGI, 0, 1, 1),
SOC_SINGLE("Store DC Offset Switch", WM8731_APDIGI, 4, 1, 0),
-SOC_ENUM("Playback De-emphasis", wm8731_deemph_enum),
+SOC_SINGLE_BOOL_EXT("Playback Deemphasis Switch", 0,
+ wm8731_get_deemph, wm8731_put_deemph),
};
/* Output Mixer */
@@ -243,6 +305,8 @@
u16 srate = (coeff_div[i].sr << 2) |
(coeff_div[i].bosr << 1) | coeff_div[i].usb;
+ wm8731->playback_fs = params_rate(params);
+
snd_soc_write(codec, WM8731_SRATE, srate);
/* bit size */
@@ -257,6 +321,8 @@
break;
}
+ wm8731_set_deemph(codec);
+
snd_soc_write(codec, WM8731_IFACE, iface);
return 0;
}