ASoC: add audio-graph-card support

OF-graph base DT binding are used on V4L2, and ALSA SoC is using
different style of DT today. Now ALSA SoC supports simple-card driver
for generic/simple sound card.
In the future, V4L2 / ALSA will support HDMI, and then, DT bindings
between V4L2 / ALSA should be merged.
This patch adds new Audio Graph Card which is OF-graph base of
simple-card
Signed-off-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

sound/soc/generic/Kconfig

@@ -14,3 +14,11 @@ config SND_SIMPLE_SCU_CARD
 	help
 	  This option enables generic simple SCU sound card support.
 	  It supports DPCM of multi CPU single Codec system.
+
+config SND_AUDIO_GRAPH_CARD
+	tristate "ASoC Audio Graph sound card support"
+	depends on OF
+	select SND_SIMPLE_CARD_UTILS
+	help
+	  This option enables generic simple simple sound card support
+	  with OF-graph DT bindings.

sound/soc/generic/Makefile

 snd-soc-simple-card-utils-objs	:= simple-card-utils.o
 snd-soc-simple-card-objs	:= simple-card.o
 snd-soc-simple-scu-card-objs	:= simple-scu-card.o
+snd-soc-audio-graph-card-objs	:= audio-graph-card.o
 
 obj-$(CONFIG_SND_SIMPLE_CARD_UTILS)	+= snd-soc-simple-card-utils.o
 obj-$(CONFIG_SND_SIMPLE_CARD)		+= snd-soc-simple-card.o
 obj-$(CONFIG_SND_SIMPLE_SCU_CARD)	+= snd-soc-simple-scu-card.o
+obj-$(CONFIG_SND_AUDIO_GRAPH_CARD)	+= snd-soc-audio-graph-card.o

sound/soc/generic/audio-graph-card.c

+/*
+ * ASoC audio graph sound card support
+ *
+ * Copyright (C) 2016 Renesas Solutions Corp.
+ * Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
+ *
+ * based on ${LINUX}/sound/soc/generic/simple-card.c
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * 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/device.h>
+#include <linux/gpio.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/of_device.h>
+#include <linux/of_gpio.h>
+#include <linux/of_graph.h>
+#include <linux/platform_device.h>
+#include <linux/string.h>
+#include <sound/jack.h>
+#include <sound/simple_card_utils.h>
+
+struct graph_card_data {
+	struct snd_soc_card snd_card;
+	struct graph_dai_props {
+		struct asoc_simple_dai cpu_dai;
+		struct asoc_simple_dai codec_dai;
+	} *dai_props;
+	struct snd_soc_dai_link *dai_link;
+};
+
+#define graph_priv_to_card(priv) (&(priv)->snd_card)
+#define graph_priv_to_props(priv, i) ((priv)->dai_props + (i))
+#define graph_priv_to_dev(priv) (graph_priv_to_card(priv)->dev)
+#define graph_priv_to_link(priv, i) (graph_priv_to_card(priv)->dai_link + (i))
+
+static int asoc_graph_card_startup(struct snd_pcm_substream *substream)
+{
+	struct snd_soc_pcm_runtime *rtd = substream->private_data;
+	struct graph_card_data *priv = snd_soc_card_get_drvdata(rtd->card);
+	struct graph_dai_props *dai_props = graph_priv_to_props(priv, rtd->num);
+	int ret;
+
+	ret = clk_prepare_enable(dai_props->cpu_dai.clk);
+	if (ret)
+		return ret;
+
+	ret = clk_prepare_enable(dai_props->codec_dai.clk);
+	if (ret)
+		clk_disable_unprepare(dai_props->cpu_dai.clk);
+
+	return ret;
+}
+
+static void asoc_graph_card_shutdown(struct snd_pcm_substream *substream)
+{
+	struct snd_soc_pcm_runtime *rtd = substream->private_data;
+	struct graph_card_data *priv = snd_soc_card_get_drvdata(rtd->card);
+	struct graph_dai_props *dai_props = graph_priv_to_props(priv, rtd->num);
+
+	clk_disable_unprepare(dai_props->cpu_dai.clk);
+
+	clk_disable_unprepare(dai_props->codec_dai.clk);
+}
+
+static struct snd_soc_ops asoc_graph_card_ops = {
+	.startup = asoc_graph_card_startup,
+	.shutdown = asoc_graph_card_shutdown,
+};
+
+static int asoc_graph_card_dai_init(struct snd_soc_pcm_runtime *rtd)
+{
+	struct graph_card_data *priv =	snd_soc_card_get_drvdata(rtd->card);
+	struct snd_soc_dai *codec = rtd->codec_dai;
+	struct snd_soc_dai *cpu = rtd->cpu_dai;
+	struct graph_dai_props *dai_props =
+		graph_priv_to_props(priv, rtd->num);
+	int ret;
+
+	ret = asoc_simple_card_init_dai(codec, &dai_props->codec_dai);
+	if (ret < 0)
+		return ret;
+
+	ret = asoc_simple_card_init_dai(cpu, &dai_props->cpu_dai);
+	if (ret < 0)
+		return ret;
+
+	return 0;
+}
+
+static int asoc_graph_card_dai_link_of(struct device_node *cpu_port,
+					struct graph_card_data *priv,
+					int idx)
+{
+	struct device *dev = graph_priv_to_dev(priv);
+	struct snd_soc_dai_link *dai_link = graph_priv_to_link(priv, idx);
+	struct graph_dai_props *dai_props = graph_priv_to_props(priv, idx);
+	struct asoc_simple_dai *cpu_dai = &dai_props->cpu_dai;
+	struct asoc_simple_dai *codec_dai = &dai_props->codec_dai;
+	struct snd_soc_card *card = graph_priv_to_card(priv);
+	struct device_node *cpu_ep    = of_get_next_child(cpu_port, NULL);
+	struct device_node *codec_ep = of_graph_get_remote_endpoint(cpu_ep);
+	struct device_node *rcpu_ep = of_graph_get_remote_endpoint(codec_ep);
+	int ret;
+
+	if (rcpu_ep != cpu_ep) {
+		dev_err(dev, "remote-endpoint missmatch (%s/%s/%s)\n",
+			cpu_ep->name, codec_ep->name, rcpu_ep->name);
+		ret = -EINVAL;
+		goto dai_link_of_err;
+	}
+
+	ret = asoc_simple_card_parse_daifmt(dev, cpu_ep, codec_ep,
+					    NULL, &dai_link->dai_fmt);
+	if (ret < 0)
+		goto dai_link_of_err;
+
+	/*
+	 * we need to consider "mclk-fs" around here
+	 * see simple-card
+	 */
+
+	ret = asoc_simple_card_parse_graph_cpu(cpu_ep, dai_link);
+	if (ret < 0)
+		goto dai_link_of_err;
+
+	ret = asoc_simple_card_parse_graph_codec(codec_ep, dai_link);
+	if (ret < 0)
+		goto dai_link_of_err;
+
+	ret = snd_soc_of_parse_tdm_slot(cpu_ep,
+					&cpu_dai->tx_slot_mask,
+					&cpu_dai->rx_slot_mask,
+					&cpu_dai->slots,
+					&cpu_dai->slot_width);
+	if (ret < 0)
+		goto dai_link_of_err;
+
+	ret = snd_soc_of_parse_tdm_slot(codec_ep,
+					&codec_dai->tx_slot_mask,
+					&codec_dai->rx_slot_mask,
+					&codec_dai->slots,
+					&codec_dai->slot_width);
+	if (ret < 0)
+		goto dai_link_of_err;
+
+	ret = asoc_simple_card_parse_clk_cpu(dev, cpu_ep, dai_link, cpu_dai);
+	if (ret < 0)
+		goto dai_link_of_err;
+
+	ret = asoc_simple_card_parse_clk_codec(dev, codec_ep, dai_link, codec_dai);
+	if (ret < 0)
+		goto dai_link_of_err;
+
+	ret = asoc_simple_card_canonicalize_dailink(dai_link);
+	if (ret < 0)
+		goto dai_link_of_err;
+
+	ret = asoc_simple_card_set_dailink_name(dev, dai_link,
+						"%s-%s",
+						dai_link->cpu_dai_name,
+						dai_link->codec_dai_name);
+	if (ret < 0)
+		goto dai_link_of_err;
+
+	dai_link->ops = &asoc_graph_card_ops;
+	dai_link->init = asoc_graph_card_dai_init;
+
+	dev_dbg(dev, "\tname : %s\n", dai_link->stream_name);
+	dev_dbg(dev, "\tformat : %04x\n", dai_link->dai_fmt);
+	dev_dbg(dev, "\tcpu : %s / %d\n",
+		dai_link->cpu_dai_name,
+		cpu_dai->sysclk);
+	dev_dbg(dev, "\tcodec : %s / %d\n",
+		dai_link->codec_dai_name,
+		codec_dai->sysclk);
+
+	asoc_simple_card_canonicalize_cpu(dai_link,
+					  card->num_links == 1);
+
+dai_link_of_err:
+	of_node_put(cpu_ep);
+	of_node_put(rcpu_ep);
+	of_node_put(codec_ep);
+
+	return ret;
+}
+
+static int asoc_graph_card_parse_of(struct graph_card_data *priv)
+{
+	struct of_phandle_iterator it;
+	struct device *dev = graph_priv_to_dev(priv);
+	struct snd_soc_card *card = graph_priv_to_card(priv);
+	struct device_node *node = dev->of_node;
+	int rc, idx = 0;
+	int ret;
+
+	/*
+	 * we need to consider "widgets", "routing", "mclk-fs" around here
+	 * see simple-card
+	 */
+
+	of_for_each_phandle(&it, rc, node, "dais", NULL, 0) {
+		ret = asoc_graph_card_dai_link_of(it.node, priv, idx++);
+		of_node_put(it.node);
+		if (ret < 0)
+			return ret;
+	}
+
+	return asoc_simple_card_parse_card_name(card, NULL);
+}
+
+static int asoc_graph_get_dais_count(struct device *dev)
+{
+	struct of_phandle_iterator it;
+	struct device_node *node = dev->of_node;
+	int count = 0;
+	int rc;
+
+	of_for_each_phandle(&it, rc, node, "dais", NULL, 0) {
+		count++;
+		of_node_put(it.node);
+	}
+
+	return count;
+}
+
+static int asoc_graph_card_probe(struct platform_device *pdev)
+{
+	struct graph_card_data *priv;
+	struct snd_soc_dai_link *dai_link;
+	struct graph_dai_props *dai_props;
+	struct device *dev = &pdev->dev;
+	struct snd_soc_card *card;
+	int num, ret;
+
+	/* Allocate the private data and the DAI link array */
+	priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
+	if (!priv)
+		return -ENOMEM;
+
+	num = asoc_graph_get_dais_count(dev);
+	if (num == 0)
+		return -EINVAL;
+
+	dai_props = devm_kzalloc(dev, sizeof(*dai_props) * num, GFP_KERNEL);
+	dai_link  = devm_kzalloc(dev, sizeof(*dai_link)  * num, GFP_KERNEL);
+	if (!dai_props || !dai_link)
+		return -ENOMEM;
+
+	priv->dai_props			= dai_props;
+	priv->dai_link			= dai_link;
+
+	/* Init snd_soc_card */
+	card = graph_priv_to_card(priv);
+	card->owner	= THIS_MODULE;
+	card->dev	= dev;
+	card->dai_link	= dai_link;
+	card->num_links	= num;
+
+	ret = asoc_graph_card_parse_of(priv);
+	if (ret < 0) {
+		if (ret != -EPROBE_DEFER)
+			dev_err(dev, "parse error %d\n", ret);
+		goto err;
+	}
+
+	snd_soc_card_set_drvdata(card, priv);
+
+	ret = devm_snd_soc_register_card(dev, card);
+	if (ret >= 0)
+		return ret;
+err:
+	asoc_simple_card_clean_reference(card);
+
+	return ret;
+}
+
+static int asoc_graph_card_remove(struct platform_device *pdev)
+{
+	struct snd_soc_card *card = platform_get_drvdata(pdev);
+
+	return asoc_simple_card_clean_reference(card);
+}
+
+static const struct of_device_id asoc_graph_of_match[] = {
+	{ .compatible = "audio-graph-card", },
+	{},
+};
+MODULE_DEVICE_TABLE(of, asoc_graph_of_match);
+
+static struct platform_driver asoc_graph_card = {
+	.driver = {
+		.name = "asoc-audio-graph-card",
+		.of_match_table = asoc_graph_of_match,
+	},
+	.probe = asoc_graph_card_probe,
+	.remove = asoc_graph_card_remove,
+};
+module_platform_driver(asoc_graph_card);
+
+MODULE_ALIAS("platform:asoc-audio-graph-card");
+MODULE_LICENSE("GPL v2");
+MODULE_DESCRIPTION("ASoC Audio Graph Sound Card");
+MODULE_AUTHOR("Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>");