ASoC: simple-card: add Device Tree support

Support for loading the simple-card module via DeviceTree.
It requests CPU/CODEC information.
Signed-off-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Signed-off-by: Mark Brown <broonie@linaro.org>

Documentation/devicetree/bindings/sound/simple-card.txt

+Simple-Card:
+
+Simple-Card specifies audio DAI connection of SoC <-> codec.
+
+Required properties:
+
+- compatible				: "simple-audio-card"
+
+Optional properties:
+
+- simple-audio-card,format		: CPU/CODEC common audio format.
+					"i2s", "right_j", "left_j" , "dsp_a"
+					"dsp_b", "ac97", "pdm", "msb", "lsb"
+Required subnodes:
+
+- simple-audio-card,cpu			: CPU   sub-node
+- simple-audio-card,codec		: CODEC sub-node
+
+Required CPU/CODEC subnodes properties:
+
+- sound-dai				: phandle and port of CPU/CODEC
+
+Optional CPU/CODEC subnodes properties:
+
+- format				: CPU/CODEC specific audio format if needed.
+					  see simple-audio-card,format
+- frame-master				: bool property. add this if subnode is frame master
+- bitclock-master			: bool property. add this if subnode is bitclock master
+- bitclock-inversion			: bool property. add this if subnode has clock inversion
+- frame-inversion			: bool property. add this if subnode has frame inversion
+- 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)
+
+Example:
+
+sound {
+	compatible = "simple-audio-card";
+	simple-audio-card,format = "left_j";
+
+	simple-audio-card,cpu {
+		sound-dai = <&sh_fsi2 0>;
+	};
+
+	simple-audio-card,codec {
+		sound-dai = <&ak4648>;
+		bitclock-master;
+		frame-master;
+		clocks = <&osc>;
+	};
+};
+
+&i2c0 {
+	ak4648: ak4648@12 {
+		#sound-dai-cells = <0>;
+		compatible = "asahi-kasei,ak4648";
+		reg = <0x12>;
+	};
+};
+
+sh_fsi2: sh_fsi2@ec230000 {
+	#sound-dai-cells = <1>;
+	compatible = "renesas,sh_fsi2";
+	reg = <0xec230000 0x400>;
+	interrupt-parent = <&gic>;
+	interrupts = <0 146 0x4>;
+};

sound/soc/generic/simple-card.c

@@ -8,7 +8,8 @@
  * it under the terms of the GNU General Public License version 2 as
  * published by the Free Software Foundation.
  */
-
+#include <linux/clk.h>
+#include <linux/of.h>
 #include <linux/platform_device.h>
 #include <linux/module.h>
 #include <sound/simple_card.h>
@@ -57,11 +58,144 @@ static int asoc_simple_card_dai_init(struct snd_soc_pcm_runtime *rtd)
 	return 0;
 }
 
+static int
+asoc_simple_card_sub_parse_of(struct device_node *np,
+			      struct asoc_simple_dai *dai,
+			      struct device_node **node)
+{
+	struct clk *clk;
+	int ret;
+
+	/*
+	 * get node via "sound-dai = <&phandle port>"
+	 * it will be used as xxx_of_node on soc_bind_dai_link()
+	 */
+	*node = of_parse_phandle(np, "sound-dai", 0);
+	if (!*node)
+		return -ENODEV;
+
+	/* get dai->name */
+	ret = snd_soc_of_get_dai_name(np, &dai->name);
+	if (ret < 0)
+		goto parse_error;
+
+	/*
+	 * bitclock-inversion, frame-inversion
+	 * bitclock-master,    frame-master
+	 * and specific "format" if it has
+	 */
+	dai->fmt = snd_soc_of_parse_daifmt(np, NULL);
+
+	/*
+	 * dai->sysclk come from
+	 *  "clocks = <&xxx>" (if system has common clock)
+	 *  or "system-clock-frequency = <xxx>"
+	 */
+	clk = of_clk_get(np, 0);
+	if (IS_ERR(clk))
+		of_property_read_u32(np,
+				     "system-clock-frequency",
+				     &dai->sysclk);
+	else
+		dai->sysclk = clk_get_rate(clk);
+
+	ret = 0;
+
+parse_error:
+	of_node_put(*node);
+
+	return ret;
+}
+
+static int asoc_simple_card_parse_of(struct device_node *node,
+				     struct asoc_simple_card_info *info,
+				     struct device *dev,
+				     struct device_node **of_cpu,
+				     struct device_node **of_codec,
+				     struct device_node **of_platform)
+{
+	struct device_node *np;
+	char *name;
+	int ret = 0;
+
+	/* get CPU/CODEC common format via simple-audio-card,format */
+	info->daifmt = snd_soc_of_parse_daifmt(node, "simple-audio-card,") &
+		(SND_SOC_DAIFMT_FORMAT_MASK | SND_SOC_DAIFMT_INV_MASK);
+
+	/* CPU sub-node */
+	ret = -EINVAL;
+	np = of_get_child_by_name(node, "simple-audio-card,cpu");
+	if (np)
+		ret = asoc_simple_card_sub_parse_of(np,
+						  &info->cpu_dai,
+						  of_cpu);
+	if (ret < 0)
+		return ret;
+
+	/* CODEC sub-node */
+	ret = -EINVAL;
+	np = of_get_child_by_name(node, "simple-audio-card,codec");
+	if (np)
+		ret = asoc_simple_card_sub_parse_of(np,
+						  &info->codec_dai,
+						  of_codec);
+	if (ret < 0)
+		return ret;
+
+	/* card name is created from CPU/CODEC dai name */
+	name = devm_kzalloc(dev,
+			    strlen(info->cpu_dai.name)   +
+			    strlen(info->codec_dai.name) + 2,
+			    GFP_KERNEL);
+	sprintf(name, "%s-%s", info->cpu_dai.name, info->codec_dai.name);
+	info->name = info->card = name;
+
+	/* simple-card assumes platform == cpu */
+	*of_platform = *of_cpu;
+
+	dev_dbg(dev, "card-name : %s\n", info->card);
+	dev_dbg(dev, "platform : %04x\n", info->daifmt);
+	dev_dbg(dev, "cpu : %s / %04x / %d\n",
+		info->cpu_dai.name,
+		info->cpu_dai.fmt,
+		info->cpu_dai.sysclk);
+	dev_dbg(dev, "codec : %s / %04x / %d\n",
+		info->codec_dai.name,
+		info->codec_dai.fmt,
+		info->codec_dai.sysclk);
+
+	return 0;
+}
+
 static int asoc_simple_card_probe(struct platform_device *pdev)
 {
-	struct asoc_simple_card_info *cinfo = pdev->dev.platform_data;
+	struct asoc_simple_card_info *cinfo;
+	struct device_node *np = pdev->dev.of_node;
+	struct device_node *of_cpu, *of_codec, *of_platform;
 	struct device *dev = &pdev->dev;
 
+	cinfo		= NULL;
+	of_cpu		= NULL;
+	of_codec	= NULL;
+	of_platform	= NULL;
+	if (np && of_device_is_available(np)) {
+		cinfo = devm_kzalloc(dev, sizeof(*cinfo), GFP_KERNEL);
+		if (cinfo) {
+			int ret;
+			ret = asoc_simple_card_parse_of(np, cinfo, dev,
+							&of_cpu,
+							&of_codec,
+							&of_platform);
+			if (ret < 0) {
+				if (ret != -EPROBE_DEFER)
+					dev_err(dev, "parse error %d\n", ret);
+				return ret;
+			}
+		}
+	} else {
+		cinfo = pdev->dev.platform_data;
+	}
+
 	if (!cinfo) {
 		dev_err(dev, "no info for asoc-simple-card\n");
 		return -EINVAL;
@@ -69,10 +203,10 @@ static int asoc_simple_card_probe(struct platform_device *pdev)
 
 	if (!cinfo->name	||
 	    !cinfo->card	||
-	    !cinfo->codec	||
-	    !cinfo->platform	||
-	    !cinfo->cpu_dai.name ||
-	    !cinfo->codec_dai.name) {
+	    !cinfo->codec_dai.name	||
+	    !(cinfo->codec		|| of_codec)	||
+	    !(cinfo->platform		|| of_platform)	||
+	    !(cinfo->cpu_dai.name	|| of_cpu)) {
 		dev_err(dev, "insufficient asoc_simple_card_info settings\n");
 		return -EINVAL;
 	}
@@ -86,6 +220,9 @@ static int asoc_simple_card_probe(struct platform_device *pdev)
 	cinfo->snd_link.platform_name	= cinfo->platform;
 	cinfo->snd_link.codec_name	= cinfo->codec;
 	cinfo->snd_link.codec_dai_name	= cinfo->codec_dai.name;
+	cinfo->snd_link.cpu_of_node	= of_cpu;
+	cinfo->snd_link.codec_of_node	= of_codec;
+	cinfo->snd_link.platform_of_node = of_platform;
 	cinfo->snd_link.init		= asoc_simple_card_dai_init;
 
 	/*
@@ -107,10 +244,17 @@ static int asoc_simple_card_remove(struct platform_device *pdev)
 	return snd_soc_unregister_card(&cinfo->snd_card);
 }
 
+static const struct of_device_id asoc_simple_of_match[] = {
+	{ .compatible = "simple-audio-card", },
+	{},
+};
+MODULE_DEVICE_TABLE(of, asoc_simple_of_match);
+
 static struct platform_driver asoc_simple_card = {
 	.driver = {
 		.name	= "asoc-simple-card",
 		.owner = THIS_MODULE,
+		.of_match_table = asoc_simple_of_match,
 	},
 	.probe		= asoc_simple_card_probe,
 	.remove		= asoc_simple_card_remove,