At Mon, 9 Nov 2009 15:17:24 +0000 (GMT), Daniel Drake wrote:

Our contacts at Conexant suggested that we reduce the external microphone bias to 50% in order to center the input signal with the DC input range of the codec. This is because the microphone port is DC coupled for potential use with sensors.

Signed-off-by: Daniel Drake dsd@laptop.org

Although I don't particularly like the dynamic struct array initialization that this patch changes to, its change is pretty small and this is what we'd need at this moment. So I applied it as is for 2.6.32.

Thanks!

Takashi

---

sound/pci/hda/patch_conexant.c | 15 ++++++++++++--- 1 files changed, 12 insertions(+), 3 deletions(-)

diff --git a/sound/pci/hda/patch_conexant.c b/sound/pci/hda/patch_conexant.c index 5d3a25d..ace8898 100644 --- a/sound/pci/hda/patch_conexant.c +++ b/sound/pci/hda/patch_conexant.c @@ -110,6 +110,7 @@ struct conexant_spec {

unsigned int dell_automute; unsigned int port_d_mode;

• unsigned char ext_mic_bias;

};

static int conexant_playback_pcm_open(struct hda_pcm_stream *hinfo, @@ -1917,6 +1918,11 @@ static hda_nid_t cxt5066_adc_nids[3] = { 0x14, 0x15, 0x16 }; static hda_nid_t cxt5066_capsrc_nids[1] = { 0x17 }; #define CXT5066_SPDIF_OUT 0x21

+/* OLPC's microphone port is DC coupled for use with external sensors,

• • therefore we use a 50% mic bias in order to center the input signal with
• • the DC input range of the codec. */

+#define CXT5066_OLPC_EXT_MIC_BIAS PIN_VREF50

static struct hda_channel_mode cxt5066_modes[1] = { { 2, NULL }, }; @@ -1970,9 +1976,10 @@ static int cxt5066_hp_master_sw_put(struct snd_kcontrol *kcontrol, /* toggle input of built-in and mic jack appropriately */ static void cxt5066_automic(struct hda_codec *codec) {

• static struct hda_verb ext_mic_present[] = {

• struct conexant_spec *spec = codec->spec;
• struct hda_verb ext_mic_present[] = { /* enable external mic, port B */

• {0x1a, AC_VERB_SET_PIN_WIDGET_CONTROL, PIN_VREF80},
  

• {0x1a, AC_VERB_SET_PIN_WIDGET_CONTROL, spec->ext_mic_bias},
  
  

  /* switch to external mic input */ {0x17, AC_VERB_SET_CONNECT_SEL, 0},

@@ -2225,7 +2232,7 @@ static struct hda_verb cxt5066_init_verbs_olpc[] = { {0x19, AC_VERB_SET_CONNECT_SEL, 0x00}, /* DAC1 */

/* Port B: external microphone */

• {0x1a, AC_VERB_SET_PIN_WIDGET_CONTROL, PIN_VREF80},

• {0x1a, AC_VERB_SET_PIN_WIDGET_CONTROL, CXT5066_OLPC_EXT_MIC_BIAS},

  /* Port C: internal microphone */ {0x1b, AC_VERB_SET_PIN_WIDGET_CONTROL, PIN_VREF80},

@@ -2343,6 +2350,7 @@ static int patch_cxt5066(struct hda_codec *codec) spec->input_mux = &cxt5066_capture_source;

spec->port_d_mode = PIN_HP;

• spec->ext_mic_bias = PIN_VREF80;

  spec->num_init_verbs = 1; spec->init_verbs[0] = cxt5066_init_verbs;

@@ -2374,6 +2382,7 @@ static int patch_cxt5066(struct hda_codec *codec) spec->mixers[spec->num_mixers++] = cxt5066_mixer_master_olpc; spec->mixers[spec->num_mixers++] = cxt5066_mixers; spec->port_d_mode = 0;

• spec->ext_mic_bias = CXT5066_OLPC_EXT_MIC_BIAS;
  
  

  /* no S/PDIF out */ spec->multiout.dig_out_nid = 0;

-- 1.6.2.5