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ASoC: Automatically manage WM8731 deemphasis

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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>
This commit is contained in:
Mark Brown 2010-12-02 11:44:00 +00:00
parent 59f7297014
commit dd31b310b9
1 changed files with 71 additions and 5 deletions
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76
sound/soc/codecs/wm8731.c
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@ -46,6 +46,8 @@ struct wm8731_priv {
u16 reg_cache[WM8731_CACHEREGNUM];
unsigned int sysclk;
int sysclk_type;
int playback_fs;
bool deemph;
};
@ -65,14 +67,73 @@ static const u16 wm8731_reg[WM8731_CACHEREGNUM] = {
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_TLV("Sidetone Playback Volume", WM8731_APANA, 6, 3, 1,
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 @@ static int wm8731_hw_params(struct snd_pcm_substream *substream,
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 @@ static int wm8731_hw_params(struct snd_pcm_substream *substream,
break;
}
wm8731_set_deemph(codec);
snd_soc_write(codec, WM8731_IFACE, iface);
return 0;
}