ASoC: add audio-graph-scu-card support

OF-graph base DT binding is 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, and we have simple-scu-card driver
for simple-card + ALSA DPCM case.
In the future, V4L2 / ALSA will support HDMI, and then, DT bindings
between V4L2 / ALSA should be merged.
This patch adds new Audio Graph SCU Card which is OF-graph base of
simple-scu-card

Signed-off-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

sound/soc/generic/Kconfig

@@ -22,3 +22,12 @@ config SND_AUDIO_GRAPH_CARD
 	help
 	  This option enables generic simple simple sound card support
 	  with OF-graph DT bindings.
+
+config SND_AUDIO_GRAPH_SCU_CARD
+	tristate "ASoC Audio Graph SCU sound card support"
+	depends on OF
+	select SND_SIMPLE_CARD_UTILS
+	help
+	  This option enables generic simple SCU sound card support
+	  with OF-graph DT bindings.
+	  It supports DPCM of multi CPU single Codec ststem.

sound/soc/generic/Makefile

@@ -2,8 +2,10 @@ 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
+snd-soc-audio-graph-scu-card-objs	:= audio-graph-scu-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
+obj-$(CONFIG_SND_AUDIO_GRAPH_SCU_CARD)	+= snd-soc-audio-graph-scu-card.o

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

@@ -0,0 +1,416 @@
+/*
+ * ASoC audio graph SCU sound card support
+ *
+ * Copyright (C) 2017 Renesas Solutions Corp.
+ * Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
+ *
+ * based on
+ *	${LINUX}/sound/soc/generic/simple-scu-card.c
+ *	${LINUX}/sound/soc/generic/audio-graph-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 snd_soc_codec_conf codec_conf;
+	struct asoc_simple_dai *dai_props;
+	struct snd_soc_dai_link *dai_link;
+	u32 convert_rate;
+	u32 convert_channels;
+};
+
+#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 asoc_simple_dai *dai_props = graph_priv_to_props(priv, rtd->num);
+
+	return clk_prepare_enable(dai_props->clk);
+}
+
+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 asoc_simple_dai *dai_props = graph_priv_to_props(priv, rtd->num);
+
+	clk_disable_unprepare(dai_props->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 *dai;
+	struct snd_soc_dai_link *dai_link;
+	struct asoc_simple_dai *dai_props;
+	int num = rtd->num;
+
+	dai_link	= graph_priv_to_link(priv, num);
+	dai_props	= graph_priv_to_props(priv, num);
+	dai		= dai_link->dynamic ?
+				rtd->cpu_dai :
+				rtd->codec_dai;
+
+	return asoc_simple_card_init_dai(dai, dai_props);
+}
+
+static int asoc_graph_card_be_hw_params_fixup(struct snd_soc_pcm_runtime *rtd,
+					       struct snd_pcm_hw_params *params)
+{
+	struct graph_card_data *priv = snd_soc_card_get_drvdata(rtd->card);
+	struct snd_interval *rate = hw_param_interval(params,
+						      SNDRV_PCM_HW_PARAM_RATE);
+	struct snd_interval *channels = hw_param_interval(params,
+							  SNDRV_PCM_HW_PARAM_CHANNELS);
+
+	if (priv->convert_rate)
+		rate->min =
+		rate->max = priv->convert_rate;
+
+	if (priv->convert_channels)
+		channels->min =
+		channels->max = priv->convert_channels;
+
+	return 0;
+}
+
+static int asoc_graph_card_dai_link_of(struct device_node *ep,
+				       struct graph_card_data *priv,
+				       unsigned int daifmt,
+				       int idx, int is_fe)
+{
+	struct device *dev = graph_priv_to_dev(priv);
+	struct snd_soc_dai_link *dai_link = graph_priv_to_link(priv, idx);
+	struct asoc_simple_dai *dai_props = graph_priv_to_props(priv, idx);
+	struct snd_soc_card *card = graph_priv_to_card(priv);
+	int ret;
+
+	if (is_fe) {
+		/* BE is dummy */
+		dai_link->codec_of_node		= NULL;
+		dai_link->codec_dai_name	= "snd-soc-dummy-dai";
+		dai_link->codec_name		= "snd-soc-dummy";
+
+		/* FE settings */
+		dai_link->dynamic		= 1;
+		dai_link->dpcm_merged_format	= 1;
+
+		ret = asoc_simple_card_parse_graph_cpu(ep, dai_link);
+		if (ret)
+			return ret;
+
+		ret = asoc_simple_card_parse_clk_cpu(dev, ep, dai_link, dai_props);
+		if (ret < 0)
+			return ret;
+
+		ret = asoc_simple_card_set_dailink_name(dev, dai_link,
+							"fe.%s",
+							dai_link->cpu_dai_name);
+		if (ret < 0)
+			return ret;
+
+		/* card->num_links includes Codec */
+		asoc_simple_card_canonicalize_cpu(dai_link,
+					(card->num_links - 1) == 1);
+	} else {
+		/* FE is dummy */
+		dai_link->cpu_of_node		= NULL;
+		dai_link->cpu_dai_name		= "snd-soc-dummy-dai";
+		dai_link->cpu_name		= "snd-soc-dummy";
+
+		/* BE settings */
+		dai_link->no_pcm		= 1;
+		dai_link->be_hw_params_fixup	= asoc_graph_card_be_hw_params_fixup;
+
+		ret = asoc_simple_card_parse_graph_codec(ep, dai_link);
+		if (ret < 0)
+			return ret;
+
+		ret = asoc_simple_card_parse_clk_codec(dev, ep, dai_link, dai_props);
+		if (ret < 0)
+			return ret;
+
+		ret = asoc_simple_card_set_dailink_name(dev, dai_link,
+							"be.%s",
+							dai_link->codec_dai_name);
+		if (ret < 0)
+			return ret;
+
+		snd_soc_of_parse_audio_prefix(card,
+					      &priv->codec_conf,
+					      dai_link->codec_of_node,
+					      "prefix");
+	}
+
+	ret = snd_soc_of_parse_tdm_slot(ep,
+					&dai_props->tx_slot_mask,
+					&dai_props->rx_slot_mask,
+					&dai_props->slots,
+					&dai_props->slot_width);
+	if (ret)
+		return ret;
+
+	ret = asoc_simple_card_canonicalize_dailink(dai_link);
+	if (ret < 0)
+		return ret;
+
+	dai_link->dai_fmt		= daifmt;
+	dai_link->dpcm_playback		= 1;
+	dai_link->dpcm_capture		= 1;
+	dai_link->ops			= &asoc_graph_card_ops;
+	dai_link->init			= asoc_graph_card_dai_init;
+
+	dev_dbg(dev, "\t%s / %04x / %d\n",
+		dai_link->name,
+		dai_link->dai_fmt,
+		dai_props->sysclk);
+
+	return 0;
+}
+
+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;
+	struct device_node *cpu_port;
+	struct device_node *cpu_ep;
+	struct device_node *codec_ep;
+	struct device_node *rcpu_ep;
+	unsigned int daifmt = 0;
+	int dai_idx, ret;
+	int rc, codec;
+
+	if (!node)
+		return -EINVAL;
+
+	/*
+	 * we need to consider "widgets", "mclk-fs" around here
+	 * see simple-card
+	 */
+
+	ret = snd_soc_of_parse_audio_routing(card, "routing");
+	if (ret)
+		return ret;
+
+	/* sampling rate convert */
+	of_property_read_u32(node, "convert-rate", &priv->convert_rate);
+
+	/* channels transfer */
+	of_property_read_u32(node, "convert-channels", &priv->convert_channels);
+
+	/*
+	 * it supports multi CPU, single CODEC only here
+	 * see asoc_graph_get_dais_count
+	 */
+
+	/* find 1st codec */
+	of_for_each_phandle(&it, rc, node, "dais", NULL, 0) {
+		cpu_port = it.node;
+		cpu_ep   = of_get_next_child(cpu_port, NULL);
+		codec_ep = of_graph_get_remote_endpoint(cpu_ep);
+		rcpu_ep  = of_graph_get_remote_endpoint(codec_ep);
+
+		of_node_put(cpu_port);
+		of_node_put(cpu_ep);
+		of_node_put(codec_ep);
+		of_node_put(rcpu_ep);
+
+		if (!codec_ep)
+			continue;
+
+		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 parse_of_err;
+		}
+
+		ret = asoc_simple_card_parse_daifmt(dev, cpu_ep, codec_ep,
+							    NULL, &daifmt);
+		if (ret < 0)
+			goto parse_of_err;
+	}
+
+	dai_idx = 0;
+	for (codec = 0; codec < 2; codec++) {
+		/*
+		 * To listup valid sounds continuously,
+		 * detect all CPU-dummy first, and
+		 * detect all dummy-Codec second
+		 */
+		of_for_each_phandle(&it, rc, node, "dais", NULL, 0) {
+			cpu_port = it.node;
+			cpu_ep   = of_get_next_child(cpu_port, NULL);
+			codec_ep = of_graph_get_remote_endpoint(cpu_ep);
+
+			of_node_put(cpu_port);
+			of_node_put(cpu_ep);
+			of_node_put(codec_ep);
+
+			if (codec) {
+				if (!codec_ep)
+					continue;
+
+				/* Back-End (= Codec) */
+				ret = asoc_graph_card_dai_link_of(codec_ep, priv, daifmt, dai_idx++, 0);
+				if (ret < 0)
+					goto parse_of_err;
+			} else {
+				/* Front-End (= CPU) */
+				ret = asoc_graph_card_dai_link_of(cpu_ep, priv, daifmt, dai_idx++, 1);
+				if (ret < 0)
+					goto parse_of_err;
+			}
+		}
+	}
+
+	ret = asoc_simple_card_parse_card_name(card, NULL);
+	if (ret)
+		goto parse_of_err;
+
+	dev_dbg(dev, "New card: %s\n",
+		card->name ? card->name : "");
+	dev_dbg(dev, "convert_rate     %d\n", priv->convert_rate);
+	dev_dbg(dev, "convert_channels %d\n", priv->convert_channels);
+
+	ret = 0;
+
+parse_of_err:
+	return ret;
+}
+
+static int asoc_graph_get_dais_count(struct device *dev)
+{
+	struct of_phandle_iterator it;
+	struct device_node *node = dev->of_node;
+	struct device_node *cpu_port;
+	struct device_node *cpu_ep;
+	struct device_node *codec_ep;
+	int count = 0;
+	int rc;
+
+	of_for_each_phandle(&it, rc, node, "dais", NULL, 0) {
+		cpu_port = it.node;
+		cpu_ep   = of_get_next_child(cpu_port, NULL);
+		codec_ep = of_graph_get_remote_endpoint(cpu_ep);
+
+		of_node_put(cpu_port);
+		of_node_put(cpu_ep);
+		of_node_put(codec_ep);
+
+		if (cpu_ep)
+			count++;
+		if (codec_ep)
+			count++;
+	}
+
+	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 asoc_simple_dai *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		= priv->dai_link;
+	card->num_links		= num;
+	card->codec_conf	= &priv->codec_conf;
+	card->num_configs	= 1;
+
+	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-scu-card", },
+	{},
+};
+MODULE_DEVICE_TABLE(of, asoc_graph_of_match);
+
+static struct platform_driver asoc_graph_card = {
+	.driver = {
+		.name = "asoc-audio-graph-scu-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-scu-card");
+MODULE_LICENSE("GPL v2");
+MODULE_DESCRIPTION("ASoC Audio Graph SCU Sound Card");
+MODULE_AUTHOR("Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>");