ASoC: sgtl5000: Fix VAG power-on handling

[ Upstream commit aa7812737f2877e192d57626cbe8825cc7cf6de9 ]

As mentioned slightly out of patch context in the code, there
is no reset routine for the chip. On boards where the chip is
supplied by a fixed regulator, it might not even be resetted
during (e.g. watchdog) reboot and can be in any state.

If the device is probed with VAG enabled, the driver's probe
routine will generate a loud pop sound when ANA_POWER is
being programmed. Avoid this by properly disabling just the
VAG bit and waiting the required power down time.

Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>
Reviewed-by: Fabio Estevam <festivem@gmail.com>
Link: https://lore.kernel.org/r/20200414181140.145825-1-sebastian.reichel@collabora.com
Signed-off-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/sound/soc/codecs/sgtl5000.c b/sound/soc/codecs/sgtl5000.c
index 896412d11a31c4a6e6ec02ac34add7d52fac3676..7c0a06b487f74609783bdfa792c5d111d7009068 100644 (file)
--- a/sound/soc/codecs/sgtl5000.c
+++ b/sound/soc/codecs/sgtl5000.c
@@ -1633,6 +1633,40 @@ static int sgtl5000_i2c_probe(struct i2c_client *client,
                dev_err(&client->dev,
                        "Error %d initializing CHIP_CLK_CTRL\n", ret);
 
+       /* Mute everything to avoid pop from the following power-up */
+       ret = regmap_write(sgtl5000->regmap, SGTL5000_CHIP_ANA_CTRL,
+                          SGTL5000_CHIP_ANA_CTRL_DEFAULT);
+       if (ret) {
+               dev_err(&client->dev,
+                       "Error %d muting outputs via CHIP_ANA_CTRL\n", ret);
+               goto disable_clk;
+       }
+
+       /*
+        * If VAG is powered-on (e.g. from previous boot), it would be disabled
+        * by the write to ANA_POWER in later steps of the probe code. This
+        * may create a loud pop even with all outputs muted. The proper way
+        * to circumvent this is disabling the bit first and waiting the proper
+        * cool-down time.
+        */
+       ret = regmap_read(sgtl5000->regmap, SGTL5000_CHIP_ANA_POWER, &value);
+       if (ret) {
+               dev_err(&client->dev, "Failed to read ANA_POWER: %d\n", ret);
+               goto disable_clk;
+       }
+       if (value & SGTL5000_VAG_POWERUP) {
+               ret = regmap_update_bits(sgtl5000->regmap,
+                                        SGTL5000_CHIP_ANA_POWER,
+                                        SGTL5000_VAG_POWERUP,
+                                        0);
+               if (ret) {
+                       dev_err(&client->dev, "Error %d disabling VAG\n", ret);
+                       goto disable_clk;
+               }
+
+               msleep(SGTL5000_VAG_POWERDOWN_DELAY);
+       }
+
        /* Follow section 2.2.1.1 of AN3663 */
        ana_pwr = SGTL5000_ANA_POWER_DEFAULT;
        if (sgtl5000->num_supplies <= VDDD) {

diff --git a/sound/soc/codecs/sgtl5000.h b/sound/soc/codecs/sgtl5000.h
index 18cae08bbd3a6f455d7ed763fbc7d44411498675..066517e352a701f5b57ea8ce0a566b707818e17d 100644 (file)
--- a/sound/soc/codecs/sgtl5000.h
+++ b/sound/soc/codecs/sgtl5000.h
@@ -233,6 +233,7 @@
 /*
  * SGTL5000_CHIP_ANA_CTRL
  */
+#define SGTL5000_CHIP_ANA_CTRL_DEFAULT         0x0133
 #define SGTL5000_LINE_OUT_MUTE                 0x0100
 #define SGTL5000_HP_SEL_MASK                   0x0040
 #define SGTL5000_HP_SEL_SHIFT                  6