/*
 * 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/gpio/consumer.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;
	struct gpio_desc *pa_gpio;
};

static int asoc_graph_card_outdrv_event(struct snd_soc_dapm_widget *w,
					struct snd_kcontrol *kcontrol,
					int event)
{
	struct snd_soc_dapm_context *dapm = w->dapm;
	struct graph_card_data *priv = snd_soc_card_get_drvdata(dapm->card);

	switch (event) {
	case SND_SOC_DAPM_POST_PMU:
		gpiod_set_value_cansleep(priv->pa_gpio, 1);
		break;
	case SND_SOC_DAPM_PRE_PMD:
		gpiod_set_value_cansleep(priv->pa_gpio, 0);
		break;
	default:
		return -EINVAL;
	}

	return 0;
}

static const struct snd_soc_dapm_widget asoc_graph_card_dapm_widgets[] = {
	SND_SOC_DAPM_OUT_DRV_E("Amplifier", SND_SOC_NOPM,
			       0, 0, NULL, 0, asoc_graph_card_outdrv_event,
			       SND_SOC_DAPM_POST_PMU | SND_SOC_DAPM_PRE_PMD),
};

#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 = asoc_simple_card_clk_enable(&dai_props->cpu_dai);
	if (ret)
		return ret;

	ret = asoc_simple_card_clk_enable(&dai_props->codec_dai);
	if (ret)
		asoc_simple_card_clk_disable(&dai_props->cpu_dai);

	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);

	asoc_simple_card_clk_disable(&dai_props->cpu_dai);

	asoc_simple_card_clk_disable(&dai_props->codec_dai);
}

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 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 mismatch (%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 = asoc_simple_card_of_parse_tdm(cpu_ep, cpu_dai);
	if (ret < 0)
		goto dai_link_of_err;

	ret = asoc_simple_card_of_parse_tdm(codec_ep, codec_dai);
	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;

	asoc_simple_card_canonicalize_cpu(dai_link,
		of_graph_get_endpoint_count(dai_link->cpu_of_node) == 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;

	ret = asoc_simple_card_of_parse_widgets(card, NULL);
	if (ret < 0)
		return ret;

	ret = asoc_simple_card_of_parse_routing(card, NULL, 1);
	if (ret < 0)
		return ret;

	/*
	 * we need to consider "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++);
		if (ret < 0) {
			of_node_put(it.node);

			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++;

	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->pa_gpio = devm_gpiod_get_optional(dev, "pa", GPIOD_OUT_LOW);
	if (IS_ERR(priv->pa_gpio)) {
		ret = PTR_ERR(priv->pa_gpio);
		dev_err(dev, "failed to get amplifier gpio: %d\n", ret);
		return ret;
	}

	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;
	card->dapm_widgets = asoc_graph_card_dapm_widgets;
	card->num_dapm_widgets = ARRAY_SIZE(asoc_graph_card_dapm_widgets);

	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)
		goto err;

	return 0;
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>");