ASoC: pcm512x: Trigger auto-increment of register addresses on i2c

When the codec is connected using i2c, it will only auto-increment
register addresses if msb (0x80) of the register address byte is set.

[Fixes cache sync if multiple adjacent registers are updated -- broonie]

Signed-off-by: Peter Rosin <peda@axentia.se>
Signed-off-by: Mark Brown <broonie@kernel.org>
Cc: stable@vger.kernel.org
diff --git a/sound/soc/codecs/pcm512x-i2c.c b/sound/soc/codecs/pcm512x-i2c.c
index 4d62230..d0547fa 100644
--- a/sound/soc/codecs/pcm512x-i2c.c
+++ b/sound/soc/codecs/pcm512x-i2c.c
@@ -24,8 +24,13 @@
 			     const struct i2c_device_id *id)
 {
 	struct regmap *regmap;
+	struct regmap_config config = pcm512x_regmap;
 
-	regmap = devm_regmap_init_i2c(i2c, &pcm512x_regmap);
+	/* msb needs to be set to enable auto-increment of addresses */
+	config.read_flag_mask = 0x80;
+	config.write_flag_mask = 0x80;
+
+	regmap = devm_regmap_init_i2c(i2c, &config);
 	if (IS_ERR(regmap))
 		return PTR_ERR(regmap);