ASoC: sgtl5000: Fix VAG power-on handling

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>

diff --git a/sound/soc/codecs/sgtl5000.c b/sound/soc/codecs/sgtl5000.c
index d5130193b4a2f9ba37b5502bac75b3e5a5c2f4bc..e8a8bf7b4ffed041e6e1b48430fb0702a9a74fa8 100644 (file)
--- a/sound/soc/codecs/sgtl5000.c
+++ b/sound/soc/codecs/sgtl5000.c
@@ -1653,6 +1653,40 @@ 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 a4bf4bca95bf7681bfb9f8b38dada3aa368d3c4e..56ec5863f25071ef2f78fd5c018f5b05f27c1e3b 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