Added support for mbed AudioCODEC (TLV320AIC23B)

[kirgene]

Signed-off-by: Yevhen Kyriukha kirgene@gmail.com

[pelwell]

I have a few minor nit-picks and one bigger issue:

1. The README entries are in alphabetical order, rather than grouped by functionality - please fix.
2. Likewise with the Makefile, please stick to alphabetical order.
3. Your sound card driver is so simple I think it would probably work with the simple card driver. Can you try this overlay and let me know if it works for you:

// Definitions for mbed DAC
/dts-v1/;
/plugin/;

/ {
	compatible = "brcm,bcm2708";

	fragment@0 {
		target = <&i2s>;
		__overlay__ {
			status = "okay";
		};
	};

	fragment@1 {
		target = <&i2c1>;
		__overlay__ {
			#address-cells = <1>;
                        #size-cells = <0>;
			status = "okay";

			codec: tlv320aic23-codec@1a {
				#sound-dai-cells = <0>;
				reg = <0x1a>;
				compatible = "ti,tlv320aic23";
				status = "okay";
			};
		};
	};

	fragment@2 {
		target = <&sound>;
		__overlay__ {
			compatible = "simple-audio-card";
			simple-audio-card,format = "i2s";
			simple-audio-card,name = "mbed-DAC";
			simple-audio-card,bitclock-slave = <&slave>;
			simple-audio-card,frame-slave = <&slave>;

			status = "okay";

			playback_link: simple-audio-card,dai-link@1 {
				format = "i2s";

				simple-audio-card,cpu {
					sound-dai = <&i2s>;
					system-clock-frequency = <12288000>;
				};

				slave: simple-audio-card,codec {
					sound-dai = <&codec>;
				};
			};
		};
	};
};

I've verified that it compiles, but nothing beyond that.

[kirgene]

Tried with simple audio card driver and it's working.
Updated pull request accordingly.

[pelwell]

Cool - every simple-card overlay feels like a small victory.