ASoC: rsrc-card: add Renesas sampling rate convert sound card support

Renesas sound card has "sampling rate convert" feature which
should be implemented via DPCM.
But, sound card driver point of view, it is difficult to add
this DPCM feature on simple-card driver. Especially, DT binding
support is very difficult.

This patch implements DPCM feature on DT as Renesas specific sound card.
This new driver is copied from current simple-card driver.
Main difference between simple-card and this driver are...
 1. removed unused feature from simple-card
 2. removed driver named prefix from DT property
 3. CPU will be FE, CODEC will be BE with snd-soc-dummy
 4. it supports sampling rate convert via .be_hw_params_fixup
 5. board specific routing is implemented in driver
Signed-off-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

Documentation/devicetree/bindings/sound/renesas,rsrc-card.txt

+Renesas Sampling Rate Convert Sound Card:
+
+Renesas Sampling Rate Convert Sound Card specifies audio DAI connections of SoC <-> codec.
+
+Required properties:
+
+- compatible				: "renesas,rsrc-card,<board>"
+					  Examples with soctypes are:
+					    - "renesas,rsrc-card,lager"
+					    - "renesas,rsrc-card,koelsch"
+Optional properties:
+
+- card_name				: User specified audio sound card name, one string
+					  property.
+- cpu					: CPU   sub-node
+- codec					: CODEC sub-node
+
+Optional subnode properties:
+
+- format				: CPU/CODEC common audio format.
+					  "i2s", "right_j", "left_j" , "dsp_a"
+					  "dsp_b", "ac97", "pdm", "msb", "lsb"
+- frame-master				: Indicates dai-link frame master.
+					  phandle to a cpu or codec subnode.
+- bitclock-master			: Indicates dai-link bit clock master.
+					  phandle to a cpu or codec subnode.
+- bitclock-inversion			: bool property. Add this if the
+					  dai-link uses bit clock inversion.
+- frame-inversion			: bool property. Add this if the
+					  dai-link uses frame clock inversion.
+
+Required CPU/CODEC subnodes properties:
+
+- sound-dai				: phandle and port of CPU/CODEC
+
+Optional CPU/CODEC subnodes properties:
+
+- clocks / system-clock-frequency	: specify subnode's clock if needed.
+					  it can be specified via "clocks" if system has
+					  clock node (= common clock), or "system-clock-frequency"
+					  (if system doens't support common clock)
+					  If a clock is specified, it is
+					  enabled with clk_prepare_enable()
+					  in dai startup() and disabled with
+					  clk_disable_unprepare() in dai
+					  shutdown().
+
+Example
+
+sound {
+	compatible = "renesas,rsrc-card,lager";
+
+	card-name = "rsnd-ak4643";
+	format = "left_j";
+	bitclock-master = <&sndcodec>;
+	frame-master = <&sndcodec>;
+
+	sndcpu: cpu {
+		sound-dai = <&rcar_sound>;
+	};
+
+	sndcodec: codec {
+		sound-dai = <&ak4643>;
+		system-clock-frequency = <11289600>;
+	};
+};

sound/soc/sh/Kconfig

@@ -41,6 +41,11 @@ config SND_SOC_RCAR
 	help
 	  This option enables R-Car SUR/SCU/SSIU/SSI sound support
 
+config SND_SOC_RSRC_CARD
+	tristate "Renesas Sampling Rate Convert Sound Card"
+	help
+	  This option enables simple sound if you need sampling rate convert
+
 ##
 ## Boards
 ##

sound/soc/sh/rcar/Makefile

 snd-soc-rcar-objs	:= core.o gen.o dma.o src.o adg.o ssi.o dvc.o
-obj-$(CONFIG_SND_SOC_RCAR)	+= snd-soc-rcar.o
\ No newline at end of file
+obj-$(CONFIG_SND_SOC_RCAR)	+= snd-soc-rcar.o
+
+snd-soc-rsrc-card-objs	:= rsrc-card.o
+obj-$(CONFIG_SND_SOC_RSRC_CARD)	+= snd-soc-rsrc-card.o