From dd31b310b9104327fb6bf7d2fe3b0f0f6fde4dd7 Mon Sep 17 00:00:00 2001 From: Mark Brown Date: Thu, 2 Dec 2010 11:44:00 +0000 Subject: [PATCH] ASoC: Automatically manage WM8731 deemphasis The deemphasis filter should be selected based on sample rate for optimal performance. Signed-off-by: Mark Brown Acked-by: Liam Girdwood --- sound/soc/codecs/wm8731.c | 76 ++++++++++++++++++++++++++++++++++++--- 1 file changed, 71 insertions(+), 5 deletions(-) diff --git a/sound/soc/codecs/wm8731.c b/sound/soc/codecs/wm8731.c index 8003761a8e02..71122dc36826 100644 --- a/sound/soc/codecs/wm8731.c +++ b/sound/soc/codecs/wm8731.c @@ -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; } -- 2.34.1