ASoC: add Audio Graph Card2 Custom Sample

audio-graph-card2 has customizing support.
This means user can re-use audio-graph-card2 DT parsing, and possible
to expand to own special handling.

This patch adds Audio Graph Card2 Customize Sample Driver.
It can re-use audio-graph-card2 parsing by calling
audio_graph2_parse_of(...), and user can expand each functions by
using hooks.
Signed-off-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Link: https://lore.kernel.org/r/87v922lu3c.wl-kuninori.morimoto.gx@renesas.comSigned-off-by: Mark Brown <broonie@kernel.org>

sound/soc/generic/Kconfig

@@ -26,6 +26,12 @@ config SND_AUDIO_GRAPH_CARD2
 	  This option enables generic simple sound card2 support
 	  with OF-graph DT bindings.
 
+config SND_AUDIO_GRAPH_CARD2_CUSTOM_SAMPLE
+	tristate "ASoC Audio Graph Card2 base custom sample support"
+	depends on SND_AUDIO_GRAPH_CARD2
+	help
+	  This option enables Audio Graph Card2 base custom sample
+
 config SND_TEST_COMPONENT
 	tristate "ASoC Test component sound support"
 	depends on OF

sound/soc/generic/Makefile

@@ -3,10 +3,12 @@ snd-soc-simple-card-utils-objs	:= simple-card-utils.o
 snd-soc-simple-card-objs	:= simple-card.o
 snd-soc-audio-graph-card-objs	:= audio-graph-card.o
 snd-soc-audio-graph-card2-objs	:= audio-graph-card2.o
+snd-soc-audio-graph-card2-custom-sample-objs := audio-graph-card2-custom-sample.o
 snd-soc-test-component-objs	:= test-component.o
 
 obj-$(CONFIG_SND_SIMPLE_CARD_UTILS)	+= snd-soc-simple-card-utils.o
 obj-$(CONFIG_SND_SIMPLE_CARD)		+= snd-soc-simple-card.o
 obj-$(CONFIG_SND_AUDIO_GRAPH_CARD)	+= snd-soc-audio-graph-card.o
 obj-$(CONFIG_SND_AUDIO_GRAPH_CARD2)	+= snd-soc-audio-graph-card2.o
+obj-$(CONFIG_SND_AUDIO_GRAPH_CARD2_CUSTOM_SAMPLE) += snd-soc-audio-graph-card2-custom-sample.o
 obj-$(CONFIG_SND_TEST_COMPONENT)	+= snd-soc-test-component.o

sound/soc/generic/audio-graph-card2-custom-sample.c

+// SPDX-License-Identifier: GPL-2.0
+//
+// audio-graph-card2-custom-sample.c
+//
+// Copyright (C) 2020 Renesas Electronics Corp.
+// Copyright (C) 2020 Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
+//
+#include <linux/module.h>
+#include <linux/of_gpio.h>
+#include <linux/platform_device.h>
+#include <sound/graph_card.h>
+
+/*
+ * Custom driver can have own priv
+ * which includes asoc_simple_priv.
+ */
+struct custom_priv {
+	struct asoc_simple_priv simple_priv;
+
+	/* custom driver's own params */
+	int custom_params;
+};
+
+/* You can get custom_priv from simple_priv */
+#define simple_to_custom(simple) container_of((simple), struct custom_priv, simple_priv)
+
+static int custom_card_probe(struct snd_soc_card *card)
+{
+	struct asoc_simple_priv *simple_priv = snd_soc_card_get_drvdata(card);
+	struct custom_priv *custom_priv = simple_to_custom(simple_priv);
+	struct device *dev = simple_priv_to_dev(simple_priv);
+
+	dev_info(dev, "custom probe\n");
+
+	custom_priv->custom_params = 1;
+
+	/* you can use generic probe function */
+	return asoc_graph_card_probe(card);
+}
+
+static int custom_hook_pre(struct asoc_simple_priv *priv)
+{
+	struct device *dev = simple_priv_to_dev(priv);
+
+	/* You can custom before parsing */
+	dev_info(dev, "hook : %s\n", __func__);
+
+	return 0;
+}
+
+static int custom_hook_post(struct asoc_simple_priv *priv)
+{
+	struct device *dev = simple_priv_to_dev(priv);
+	struct snd_soc_card *card;
+
+	/* You can custom after parsing */
+	dev_info(dev, "hook : %s\n", __func__);
+
+	/* overwrite .probe sample */
+	card = simple_priv_to_card(priv);
+	card->probe = custom_card_probe;
+
+	return 0;
+}
+
+static int custom_normal(struct asoc_simple_priv *priv,
+			 struct device_node *lnk,
+			 struct link_info *li)
+{
+	struct device *dev = simple_priv_to_dev(priv);
+
+	/*
+	 * You can custom Normal parsing
+	 * before/affter audio_graph2_link_normal()
+	 */
+	dev_info(dev, "hook : %s\n", __func__);
+
+	return audio_graph2_link_normal(priv, lnk, li);
+}
+
+static int custom_dpcm(struct asoc_simple_priv *priv,
+		       struct device_node *lnk,
+		       struct link_info *li)
+{
+	struct device *dev = simple_priv_to_dev(priv);
+
+	/*
+	 * You can custom DPCM parsing
+	 * before/affter audio_graph2_link_dpcm()
+	 */
+	dev_info(dev, "hook : %s\n", __func__);
+
+	return audio_graph2_link_dpcm(priv, lnk, li);
+}
+
+static int custom_c2c(struct asoc_simple_priv *priv,
+		      struct device_node *lnk,
+		      struct link_info *li)
+{
+	struct device *dev = simple_priv_to_dev(priv);
+
+	/*
+	 * You can custom Codec2Codec parsing
+	 * before/affter audio_graph2_link_c2c()
+	 */
+	dev_info(dev, "hook : %s\n", __func__);
+
+	return audio_graph2_link_c2c(priv, lnk, li);
+}
+
+/*
+ * audio-graph-card2 has many hooks for your customizing.
+ */
+static struct graph2_custom_hooks custom_hooks = {
+	.hook_pre	= custom_hook_pre,
+	.hook_post	= custom_hook_post,
+	.custom_normal	= custom_normal,
+	.custom_dpcm	= custom_dpcm,
+	.custom_c2c	= custom_c2c,
+};
+
+static int custom_startup(struct snd_pcm_substream *substream)
+{
+	struct snd_soc_pcm_runtime *rtd = asoc_substream_to_rtd(substream);
+	struct asoc_simple_priv *priv = snd_soc_card_get_drvdata(rtd->card);
+	struct device *dev = simple_priv_to_dev(priv);
+
+	dev_info(dev, "custom startup\n");
+
+	return asoc_simple_startup(substream);
+}
+
+/* You can use custom ops */
+static const struct snd_soc_ops custom_ops = {
+	.startup	= custom_startup,
+	.shutdown	= asoc_simple_shutdown,
+	.hw_params	= asoc_simple_hw_params,
+};
+
+static int custom_probe(struct platform_device *pdev)
+{
+	struct custom_priv *custom_priv;
+	struct asoc_simple_priv *simple_priv;
+	struct device *dev = &pdev->dev;
+	int ret;
+
+	custom_priv = devm_kzalloc(dev, sizeof(*custom_priv), GFP_KERNEL);
+	if (!custom_priv)
+		return -ENOMEM;
+
+	simple_priv		= &custom_priv->simple_priv;
+	simple_priv->ops	= &custom_ops; /* customize dai_link ops */
+
+	/* use audio-graph-card2 parsing with own custom hooks */
+	ret = audio_graph2_parse_of(simple_priv, dev, &custom_hooks);
+	if (ret < 0)
+		return ret;
+
+	/* customize more if needed */
+
+	return 0;
+}
+
+static const struct of_device_id custom_of_match[] = {
+	{ .compatible = "audio-graph-card2-custom-sample", },
+	{},
+};
+MODULE_DEVICE_TABLE(of, custom_of_match);
+
+static struct platform_driver custom_card = {
+	.driver = {
+		.name = "audio-graph-card2-custom-sample",
+		.of_match_table = custom_of_match,
+	},
+	.probe	= custom_probe,
+	.remove	= asoc_simple_remove,
+};
+module_platform_driver(custom_card);
+
+MODULE_ALIAS("platform:asoc-audio-graph-card2-custom-sample");
+MODULE_LICENSE("GPL v2");
+MODULE_DESCRIPTION("ASoC Audio Graph Card2 Custom Sample");
+MODULE_AUTHOR("Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>");