// SPDX-License-Identifier: GPL-2.0+
/*
 * Normal mappings of chips in physical memory
 *
 * Copyright (C) 2003 MontaVista Software Inc.
 * Author: Jun Sun, jsun@mvista.com or jsun@junsun.net
 *
 * 031022 - [jsun] add run-time configure and partition setup
 */

#include <linux/module.h>
#include <linux/types.h>
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/slab.h>
#include <linux/device.h>
#include <linux/platform_device.h>
#include <linux/mtd/mtd.h>
#include <linux/mtd/map.h>
#include <linux/mtd/partitions.h>
#include <linux/mtd/physmap.h>
#include <linux/mtd/concat.h>
#include <linux/io.h>

struct physmap_flash_info {
	unsigned int		nmaps;
	struct mtd_info		**mtds;
	struct mtd_info		*cmtd;
	struct map_info		*maps;
	spinlock_t		vpp_lock;
	int			vpp_refcnt;
};

static int physmap_flash_remove(struct platform_device *dev)
{
	struct physmap_flash_info *info;
	struct physmap_flash_data *physmap_data;
	int i;

	info = platform_get_drvdata(dev);
	if (info == NULL)
		return 0;

	physmap_data = dev_get_platdata(&dev->dev);

	if (info->cmtd) {
		mtd_device_unregister(info->cmtd);
		if (info->cmtd != info->mtds[0])
			mtd_concat_destroy(info->cmtd);
	}

	for (i = 0; i < info->nmaps; i++) {
		if (info->mtds[i] != NULL)
			map_destroy(info->mtds[i]);
	}

	if (physmap_data->exit)
		physmap_data->exit(dev);

	return 0;
}

static void physmap_set_vpp(struct map_info *map, int state)
{
	struct platform_device *pdev;
	struct physmap_flash_data *physmap_data;
	struct physmap_flash_info *info;
	unsigned long flags;

	pdev = (struct platform_device *)map->map_priv_1;
	physmap_data = dev_get_platdata(&pdev->dev);

	if (!physmap_data->set_vpp)
		return;

	info = platform_get_drvdata(pdev);

	spin_lock_irqsave(&info->vpp_lock, flags);
	if (state) {
		if (++info->vpp_refcnt == 1)    /* first nested 'on' */
			physmap_data->set_vpp(pdev, 1);
	} else {
		if (--info->vpp_refcnt == 0)    /* last nested 'off' */
			physmap_data->set_vpp(pdev, 0);
	}
	spin_unlock_irqrestore(&info->vpp_lock, flags);
}

static const char * const rom_probe_types[] = {
	"cfi_probe", "jedec_probe", "qinfo_probe", "map_rom", NULL };

static const char * const part_probe_types[] = {
	"cmdlinepart", "RedBoot", "afs", NULL };

static int physmap_flash_probe(struct platform_device *dev)
{
	struct physmap_flash_data *physmap_data;
	struct physmap_flash_info *info;
	const char * const *probe_type;
	const char * const *part_types;
	int err = 0;
	int i;

	physmap_data = dev_get_platdata(&dev->dev);
	if (physmap_data == NULL)
		return -ENODEV;

	info = devm_kzalloc(&dev->dev, sizeof(struct physmap_flash_info),
			    GFP_KERNEL);
	if (info == NULL) {
		err = -ENOMEM;
		goto err_out;
	}

	while (platform_get_resource(dev, IORESOURCE_MEM, info->nmaps))
		info->nmaps++;

	if (!info->nmaps)
		return -ENODEV;

	info->maps = devm_kzalloc(&dev->dev,
				  sizeof(*info->maps) * info->nmaps,
				  GFP_KERNEL);
	if (!info->maps)
		return -ENOMEM;

	info->mtds = devm_kzalloc(&dev->dev,
				  sizeof(*info->mtds) * info->nmaps,
				  GFP_KERNEL);
	if (!info->mtds)
		return -ENOMEM;

	if (physmap_data->init) {
		err = physmap_data->init(dev);
		if (err)
			goto err_out;
	}

	platform_set_drvdata(dev, info);

	for (i = 0; i < info->nmaps; i++) {
		struct resource *res;

		res = platform_get_resource(dev, IORESOURCE_MEM, i);
		info->maps[i].virt = devm_ioremap_resource(&dev->dev, res);
		if (IS_ERR(info->maps[i].virt)) {
			err = PTR_ERR(info->maps[i].virt);
			goto err_out;
		}

		dev_notice(&dev->dev, "physmap platform flash device: %pR\n",
			   res);

		info->maps[i].name = dev_name(&dev->dev);
		info->maps[i].phys = res->start;
		info->maps[i].size = resource_size(res);
		info->maps[i].bankwidth = physmap_data->width;
		info->maps[i].set_vpp = physmap_set_vpp;
		info->maps[i].pfow_base = physmap_data->pfow_base;
		info->maps[i].map_priv_1 = (unsigned long)dev;

		simple_map_init(&info->maps[i]);

		probe_type = rom_probe_types;
		if (physmap_data->probe_type == NULL) {
			for (; info->mtds[i] == NULL && *probe_type != NULL; probe_type++)
				info->mtds[i] = do_map_probe(*probe_type, &info->maps[i]);
		} else
			info->mtds[i] = do_map_probe(physmap_data->probe_type, &info->maps[i]);

		if (info->mtds[i] == NULL) {
			dev_err(&dev->dev, "map_probe failed\n");
			err = -ENXIO;
			goto err_out;
		}
		info->mtds[i]->dev.parent = &dev->dev;
	}

	if (info->nmaps == 1) {
		info->cmtd = info->mtds[0];
	} else {
		/*
		 * We detected multiple devices. Concatenate them together.
		 */
		info->cmtd = mtd_concat_create(info->mtds, info->nmaps,
					       dev_name(&dev->dev));
		if (info->cmtd == NULL)
			err = -ENXIO;
	}
	if (err)
		goto err_out;

	spin_lock_init(&info->vpp_lock);

	part_types = physmap_data->part_probe_types ? : part_probe_types;

	mtd_device_parse_register(info->cmtd, part_types, NULL,
				  physmap_data->parts, physmap_data->nr_parts);
	return 0;

err_out:
	physmap_flash_remove(dev);
	return err;
}

#ifdef CONFIG_PM
static void physmap_flash_shutdown(struct platform_device *dev)
{
	struct physmap_flash_info *info = platform_get_drvdata(dev);
	int i;

	for (i = 0; i < info->nmaps && info->mtds[i]; i++)
		if (mtd_suspend(info->mtds[i]) == 0)
			mtd_resume(info->mtds[i]);
}
#else
#define physmap_flash_shutdown NULL
#endif

static struct platform_driver physmap_flash_driver = {
	.probe		= physmap_flash_probe,
	.remove		= physmap_flash_remove,
	.shutdown	= physmap_flash_shutdown,
	.driver		= {
		.name	= "physmap-flash",
	},
};


#ifdef CONFIG_MTD_PHYSMAP_COMPAT
static struct physmap_flash_data physmap_flash_data = {
	.width		= CONFIG_MTD_PHYSMAP_BANKWIDTH,
};

static struct resource physmap_flash_resource = {
	.start		= CONFIG_MTD_PHYSMAP_START,
	.end		= CONFIG_MTD_PHYSMAP_START + CONFIG_MTD_PHYSMAP_LEN - 1,
	.flags		= IORESOURCE_MEM,
};

static struct platform_device physmap_flash = {
	.name		= "physmap-flash",
	.id		= 0,
	.dev		= {
		.platform_data	= &physmap_flash_data,
	},
	.num_resources	= 1,
	.resource	= &physmap_flash_resource,
};
#endif

static int __init physmap_init(void)
{
	int err;

	err = platform_driver_register(&physmap_flash_driver);
#ifdef CONFIG_MTD_PHYSMAP_COMPAT
	if (err == 0) {
		err = platform_device_register(&physmap_flash);
		if (err)
			platform_driver_unregister(&physmap_flash_driver);
	}
#endif

	return err;
}

static void __exit physmap_exit(void)
{
#ifdef CONFIG_MTD_PHYSMAP_COMPAT
	platform_device_unregister(&physmap_flash);
#endif
	platform_driver_unregister(&physmap_flash_driver);
}

module_init(physmap_init);
module_exit(physmap_exit);

MODULE_LICENSE("GPL");
MODULE_AUTHOR("David Woodhouse <dwmw2@infradead.org>");
MODULE_DESCRIPTION("Generic configurable MTD map driver");

/* legacy platform drivers can't hotplug or coldplg */
#ifndef CONFIG_MTD_PHYSMAP_COMPAT
/* work with hotplug and coldplug */
MODULE_ALIAS("platform:physmap-flash");
#endif