ASoC: wm8962: Update register CLASS_D_CONTROL_1 to be non-volatile

The register CLASS_D_CONTROL_1 is marked as volatile because it contains
a bit, DAC_MUTE, which is also mirrored in the ADC_DAC_CONTROL_1
register. This causes problems for the "Speaker Switch" control, which
will report an error if the CODEC is suspended because it relies on a
volatile register.

To resolve this issue mark CLASS_D_CONTROL_1 as non-volatile and
manually keep the register cache in sync by updating both bits when
changing the mute status.

Reported-by: Shawn Guo <shawn.guo@linaro.org>
Signed-off-by: Charles Keepax <ckeepax@opensource.wolfsonmicro.com>
Tested-by: Shawn Guo <shawn.guo@linaro.org>
Signed-off-by: Mark Brown <broonie@linaro.org>
Cc: stable@vger.kernel.org

2 files changed, 16 insertions, 3 deletions

diff --git a/sound/soc/codecs/wm8962.c b/sound/soc/codecs/wm8962.c
index 5522d2566c67..ecd26dd2e442 100644
--- a/sound/soc/codecs/wm8962.c
+++ b/sound/soc/codecs/wm8962.c
@@ -154,6 +154,7 @@ static struct reg_default wm8962_reg[] = {
         { 40, 0x0000 },   /* R40    - SPKOUTL volume */
         { 41, 0x0000 },   /* R41    - SPKOUTR volume */
 
+        { 49, 0x0010 },   /* R49    - Class D Control 1 */
         { 51, 0x0003 },   /* R51    - Class D Control 2 */
 
         { 56, 0x0506 },   /* R56    - Clocking 4 */
@@ -795,7 +796,6 @@ static bool wm8962_volatile_register(struct device *dev, unsigned int reg)
         case WM8962_ALC2:
         case WM8962_THERMAL_SHUTDOWN_STATUS:
         case WM8962_ADDITIONAL_CONTROL_4:
-        case WM8962_CLASS_D_CONTROL_1:
         case WM8962_DC_SERVO_6:
         case WM8962_INTERRUPT_STATUS_1:
         case WM8962_INTERRUPT_STATUS_2:
@@ -2929,13 +2929,22 @@ static int wm8962_set_fll(struct snd_soc_codec *codec, int fll_id, int source,
 static int wm8962_mute(struct snd_soc_dai *dai, int mute)
 {
         struct snd_soc_codec *codec = dai->codec;
-        int val;
+        int val, ret;
 
         if (mute)
-                val = WM8962_DAC_MUTE;
+                val = WM8962_DAC_MUTE | WM8962_DAC_MUTE_ALT;
         else
                 val = 0;
 
+        /**
+         * The DAC mute bit is mirrored in two registers, update both to keep
+         * the register cache consistent.
+         */
+        ret = snd_soc_update_bits(codec, WM8962_CLASS_D_CONTROL_1,
+                                  WM8962_DAC_MUTE_ALT, val);
+        if (ret < 0)
+                return ret;
+
         return snd_soc_update_bits(codec, WM8962_ADC_DAC_CONTROL_1,
                                    WM8962_DAC_MUTE, val);
 }
diff --git a/sound/soc/codecs/wm8962.h b/sound/soc/codecs/wm8962.h
index a1a5d5294c19..910aafd09d21 100644
--- a/sound/soc/codecs/wm8962.h
+++ b/sound/soc/codecs/wm8962.h
@@ -1954,6 +1954,10 @@
 #define WM8962_SPKOUTL_ENA_MASK                 0x0040  /* SPKOUTL_ENA */
 #define WM8962_SPKOUTL_ENA_SHIFT                     6  /* SPKOUTL_ENA */
 #define WM8962_SPKOUTL_ENA_WIDTH                     1  /* SPKOUTL_ENA */
+#define WM8962_DAC_MUTE_ALT                     0x0010  /* DAC_MUTE */
+#define WM8962_DAC_MUTE_ALT_MASK                0x0010  /* DAC_MUTE */
+#define WM8962_DAC_MUTE_ALT_SHIFT                    4  /* DAC_MUTE */
+#define WM8962_DAC_MUTE_ALT_WIDTH                    1  /* DAC_MUTE */
 #define WM8962_SPKOUTL_PGA_MUTE                 0x0002  /* SPKOUTL_PGA_MUTE */
 #define WM8962_SPKOUTL_PGA_MUTE_MASK            0x0002  /* SPKOUTL_PGA_MUTE */
 #define WM8962_SPKOUTL_PGA_MUTE_SHIFT                1  /* SPKOUTL_PGA_MUTE */