// SPDX-License-Identifier: GPL-2.0
/*
 * Copyright (C) IoT.bzh 2021
 */

#include <linux/limits.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/of_reserved_mem.h>
#include <linux/platform_device.h>
#include <linux/pm_runtime.h>
#include <linux/remoteproc.h>
#include <linux/reset.h>
#include <linux/soc/renesas/rcar-rst.h>

#include "remoteproc_internal.h"

struct rcar_rproc {
	struct reset_control *rst;
};

static int rcar_rproc_prepare(struct rproc *rproc)
{
	struct device *dev = rproc->dev.parent;
	struct device_node *np = dev->of_node;
	struct rproc_mem_entry *mem;
	int i = 0;
	u32 da;

	/* Register associated reserved memory regions */
	while (1) {
		struct resource res;
		int ret;

		ret = of_reserved_mem_region_to_resource(np, i++, &res);
		if (ret)
			return 0;

		if (res.start > U32_MAX)
			return -EINVAL;

		/* No need to translate pa to da, R-Car use same map */
		da = res.start;
		mem = rproc_mem_entry_init(dev, NULL,
					   res.start,
					   resource_size(&res), da,
					   rproc_mem_entry_ioremap_wc,
					   rproc_mem_entry_iounmap,
					   res.name);

		if (!mem)
			return -ENOMEM;

		rproc_add_carveout(rproc, mem);
	}
}

static int rcar_rproc_parse_fw(struct rproc *rproc, const struct firmware *fw)
{
	rproc_elf_load_rsc_table_optional(rproc, fw, dev_info,
					  "No resource table in elf\n");
	return 0;
}

static int rcar_rproc_start(struct rproc *rproc)
{
	struct rcar_rproc *priv = rproc->priv;
	int err;

	if (!rproc->bootaddr)
		return -EINVAL;

	err = rcar_rst_set_rproc_boot_addr(rproc->bootaddr);
	if (err) {
		dev_err(&rproc->dev, "failed to set rproc boot addr\n");
		return err;
	}

	err = reset_control_deassert(priv->rst);
	if (err)
		dev_err(&rproc->dev, "failed to deassert reset\n");

	return err;
}

static int rcar_rproc_stop(struct rproc *rproc)
{
	struct rcar_rproc *priv = rproc->priv;
	int err;

	err = reset_control_assert(priv->rst);
	if (err)
		dev_err(&rproc->dev, "failed to assert reset\n");

	return err;
}

static struct rproc_ops rcar_rproc_ops = {
	.prepare	= rcar_rproc_prepare,
	.start		= rcar_rproc_start,
	.stop		= rcar_rproc_stop,
	.load		= rproc_elf_load_segments,
	.parse_fw	= rcar_rproc_parse_fw,
	.find_loaded_rsc_table = rproc_elf_find_loaded_rsc_table,
	.sanity_check	= rproc_elf_sanity_check,
	.get_boot_addr	= rproc_elf_get_boot_addr,

};

static int rcar_rproc_probe(struct platform_device *pdev)
{
	struct device *dev = &pdev->dev;
	struct device_node *np = dev->of_node;
	struct rcar_rproc *priv;
	struct rproc *rproc;
	int ret;

	rproc = devm_rproc_alloc(dev, np->name, &rcar_rproc_ops,
				NULL, sizeof(*priv));
	if (!rproc)
		return -ENOMEM;

	priv = rproc->priv;

	priv->rst = devm_reset_control_get_exclusive(dev, NULL);
	if (IS_ERR(priv->rst)) {
		ret = PTR_ERR(priv->rst);
		dev_err_probe(dev, ret, "fail to acquire rproc reset\n");
		return ret;
	}

	pm_runtime_enable(dev);
	ret = pm_runtime_resume_and_get(dev);
	if (ret) {
		dev_err(dev, "failed to power up\n");
		return ret;
	}

	dev_set_drvdata(dev, rproc);

	/* Manually start the rproc */
	rproc->auto_boot = false;

	ret = devm_rproc_add(dev, rproc);
	if (ret) {
		dev_err(dev, "rproc_add failed\n");
		goto pm_disable;
	}

	return 0;

pm_disable:
	pm_runtime_disable(dev);

	return ret;
}

static void rcar_rproc_remove(struct platform_device *pdev)
{
	struct device *dev = &pdev->dev;

	pm_runtime_disable(dev);
}

static const struct of_device_id rcar_rproc_of_match[] = {
	{ .compatible = "renesas,rcar-cr7" },
	{},
};

MODULE_DEVICE_TABLE(of, rcar_rproc_of_match);

static struct platform_driver rcar_rproc_driver = {
	.probe = rcar_rproc_probe,
	.remove = rcar_rproc_remove,
	.driver = {
		.name = "rcar-rproc",
		.of_match_table = rcar_rproc_of_match,
	},
};

module_platform_driver(rcar_rproc_driver);

MODULE_LICENSE("GPL v2");
MODULE_DESCRIPTION("Renesas R-Car Gen3 remote processor control driver");
MODULE_AUTHOR("Julien Massot <julien.massot@iot.bzh>");