ALSA: ASoC: add codec driver for TI TAS5086

This patch adds a driver for TI's TA5086 6-channel PWM processor.

This chip has a very unusual register layout, specifically because the
registers are of unequal size, and multi-byte registers require bulk
writes to take effect. Regmap does not support these kind of mappings.

Currently, the driver does not touch any of the registers >= 0x20, so
it doesn't matter, because the register map is mapped to an 8-bit array.
In case more features will be added in the future that require access
to higher registers, the entire regmap H/W I/O routines have to be
open-coded.

Signed-off-by: Daniel Mack <zonque@gmail.com>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>

1 files changed, 32 insertions, 0 deletions

diff --git a/Documentation/devicetree/bindings/sound/ti,tas5086.txt b/Documentation/devicetree/bindings/sound/ti,tas5086.txt
new file mode 100644
index 000000000000..8ea4f5b4818d
--- /dev/null
+++ b/Documentation/devicetree/bindings/sound/ti,tas5086.txt
@@ -0,0 +1,32 @@
+Texas Instruments TAS5086 6-channel PWM Processor
+
+Required properties:
+
+ - compatible:		Should contain "ti,tas5086".
+ - reg:			The i2c address. Should contain <0x1b>.
+
+Optional properties:
+
+ - reset-gpio: 		A GPIO spec to define which pin is connected to the
+			chip's !RESET pin. If specified, the driver will
+			assert a hardware reset at probe time.
+
+ - ti,charge-period:	This property should contain the time in microseconds
+			that closely matches the external single-ended
+			split-capacitor charge period. The hardware chip
+			waits for this period of time before starting the
+			PWM signals. This helps reduce pops and clicks.
+
+			When not specified, the hardware default of 1300ms
+			is retained.
+
+Examples:
+
+	i2c_bus {
+		tas5086@1b {
+			compatible = "ti,tas5086";
+			reg = <0x1b>;
+			reset-gpio = <&gpio 23 0>;
+			ti,charge-period = <156000>;
+		};
+	};