ASoC: Refresh WM8974 bias configuration

Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>

1 files changed, 23 insertions, 7 deletions

diff --git a/sound/soc/codecs/wm8974.c b/sound/soc/codecs/wm8974.c
index d2a36ad256c..c5d47bcd14a 100644
--- a/sound/soc/codecs/wm8974.c
+++ b/sound/soc/codecs/wm8974.c
@@ -46,6 +46,9 @@ static const u16 wm8974_reg[WM8974_CACHEREGNUM] = {
         0x0000,
 };
 
+#define WM8974_POWER1_BIASEN  0x08
+#define WM8974_POWER1_BUFIOEN 0x10
+
 struct wm8974_priv {
         struct snd_soc_codec codec;
         u16 reg_cache[WM8974_CACHEREGNUM];
@@ -528,22 +531,35 @@ static int wm8974_mute(struct snd_soc_dai *dai, int mute)
 static int wm8974_set_bias_level(struct snd_soc_codec *codec,
         enum snd_soc_bias_level level)
 {
+        u16 power1 = wm8974_read_reg_cache(codec, WM8974_POWER1) & ~0x3;
+
         switch (level) {
         case SND_SOC_BIAS_ON:
-                wm8974_write(codec, WM8974_POWER1, 0x1ff);
-                wm8974_write(codec, WM8974_POWER2, 0x1ff);
-                wm8974_write(codec, WM8974_POWER3, 0x1ff);
-                break;
         case SND_SOC_BIAS_PREPARE:
+                power1 |= 0x1;  /* VMID 50k */
+                wm8974_write(codec, WM8974_POWER1, power1);
                 break;
+
         case SND_SOC_BIAS_STANDBY:
+                power1 |= WM8974_POWER1_BIASEN | WM8974_POWER1_BUFIOEN;
+
+                if (codec->bias_level == SND_SOC_BIAS_OFF) {
+                        /* Initial cap charge at VMID 5k */
+                        wm8974_write(codec, WM8974_POWER1, power1 | 0x3);
+                        mdelay(100);
+                }
+
+                power1 |= 0x2;  /* VMID 500k */
+                wm8974_write(codec, WM8974_POWER1, power1);
                 break;
+
         case SND_SOC_BIAS_OFF:
-                wm8974_write(codec, WM8974_POWER1, 0x0);
-                wm8974_write(codec, WM8974_POWER2, 0x0);
-                wm8974_write(codec, WM8974_POWER3, 0x0);
+                wm8974_write(codec, WM8974_POWER1, 0);
+                wm8974_write(codec, WM8974_POWER2, 0);
+                wm8974_write(codec, WM8974_POWER3, 0);
                 break;
         }
+
         codec->bias_level = level;
         return 0;
 }