/*
 * drivers/platform/tegra/nvdumper/nvdumper.c
 *
 * Copyright (c) 2011-2018, NVIDIA CORPORATION.  All rights reserved.
 *
 * This software is licensed under the terms of the GNU General Public
 * License version 2, as published by the Free Software Foundation, and
 * may be copied, distributed, and modified under those terms.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 */

#include <linux/errno.h>
#include <linux/init.h>
#include <linux/io.h>
#include <linux/module.h>
#include <linux/of_device.h>
#include <linux/platform_device.h>
#include <linux/reboot.h>
#include <linux/slab.h>
#include <linux/uaccess.h>
#include "nvdumper.h"
#include "nvdumper-footprint.h"

#define NVDUMPER_CLEAN      0xf000caf3U
#define NVDUMPER_DIRTY      0x2badfaceU
#define NVDUMPER_DIRTY_DUMP 0xdeadbeefU
#define NVDUMPER_WDT_DUMP   0x2badbeefU
#define NVDUMPER_SET_STR_LEN 16
#define RW_MODE (S_IWUSR | S_IRUGO)
#define NV_ADDRESS_MAP_PMC_IMPL_BASE              0x0c360000
#define NV_ADDRESS_MAP_PMC_IMPL_SIZE              0x400 /* map 1k */
#define PMC_IMPL_RAMDUMP_CTL_STATUS_0             0x0000010c
#define PMC_IMPL_RAMDUMP_CTL_STATUS_0_RAMDUMP_EN  0x1

#define NVDUMPER_RESERVED_SIZE		4096UL

struct nvdumper_soc {
	bool enable_hw_ram_dump_cntrl;
};

static void __iomem *nvdumper_ptr;
static u32 nvdumper_last_reboot;
static unsigned long nvdumper_reserved;
static const struct nvdumper_soc *nvdumper_soc;
static char nvdumper_set_str[NVDUMPER_SET_STR_LEN];
static struct kobject *nvdumper_kobj;

static int __init tegra_nvdumper_arg(char *options)
{
	char *p = options;

	nvdumper_reserved = memparse(p, &p);
	pr_info("nvdumper: nvdumper_reserved is first set to 0x%lx.\n",
		nvdumper_reserved);

	return 0;
}

early_param("nvdumper_reserved", tegra_nvdumper_arg);

static void enable_hw_ram_dump_ctrl(int enable)
{
	u32 value;
	void __iomem *ram_dump_ctrl = ioremap_nocache(
			NV_ADDRESS_MAP_PMC_IMPL_BASE,
			NV_ADDRESS_MAP_PMC_IMPL_SIZE);
	if (!ram_dump_ctrl) {
		pr_info("nvdumper: failed to ioremap memory at 0x%08x\n",
			NV_ADDRESS_MAP_PMC_IMPL_BASE);
		return;
	}

	value = ioread32(ram_dump_ctrl);

	value = value & ~PMC_IMPL_RAMDUMP_CTL_STATUS_0_RAMDUMP_EN;

	if (enable)
		value = value | PMC_IMPL_RAMDUMP_CTL_STATUS_0_RAMDUMP_EN;

	iowrite32(value, ram_dump_ctrl);

	iounmap(ram_dump_ctrl);
}

static uint32_t get_dirty_state(void)
{
	return ioread32(nvdumper_ptr);
}

static void set_dirty_state(uint32_t state)
{
	pr_info("nvdumper: set_dirty_state 0x%x\n", state);
	iowrite32(state, nvdumper_ptr);

	if (!nvdumper_soc->enable_hw_ram_dump_cntrl)
		return;

	if (state == NVDUMPER_DIRTY_DUMP || state == NVDUMPER_WDT_DUMP) {
		pr_info("nvdumper: preparing wdt\n");
		enable_hw_ram_dump_ctrl(1);
	} else {
		pr_info("nvdumper: cleaning up wdt\n");
		enable_hw_ram_dump_ctrl(0);
	}
}

static int nvdumper_reboot_cb(struct notifier_block *nb,
			      unsigned long event, void *unused)
{
	pr_info("nvdumper: %s cleanly.\n",
		(event == SYS_RESTART) ? "rebooting" : "shutting down");
	set_dirty_state(NVDUMPER_CLEAN);
	return NOTIFY_DONE;
}

static struct notifier_block nvdumper_reboot_notifier = {
	.notifier_call = nvdumper_reboot_cb,
};

static ssize_t nvdumper_set_show(struct kobject *kobj,
				 struct kobj_attribute *attr,
				 char *buf)
{
	return snprintf(buf, PAGE_SIZE, "%s\n", nvdumper_set_str);
}

static ssize_t nvdumper_set_store(struct kobject *kobj,
				  struct kobj_attribute *attr,
				  const char *buf, size_t n)
{
	if (n < 1)
		return 0;

	snprintf(nvdumper_set_str, NVDUMPER_SET_STR_LEN, "%s", buf);
	nvdumper_set_str[n - 1] = '\0';

	if (!strcmp(nvdumper_set_str, "clean"))
		set_dirty_state(NVDUMPER_CLEAN);
	else if (!strcmp(nvdumper_set_str, "dirty"))
		set_dirty_state(NVDUMPER_DIRTY);
	else if (!strcmp(nvdumper_set_str, "dirty_dump"))
		set_dirty_state(NVDUMPER_DIRTY_DUMP);
	else if (!strcmp(nvdumper_set_str, "wdt_dump"))
		set_dirty_state(NVDUMPER_WDT_DUMP);
	else
		snprintf(nvdumper_set_str, NVDUMPER_SET_STR_LEN, "unknown");

	pr_info("nvdumper_set was updated to %s\n", nvdumper_set_str);

	return n;
}

static ssize_t nvdumper_prev_show(struct kobject *kobj,
				  struct kobj_attribute *attr,
				  char *buf)
{
	return snprintf(buf, PAGE_SIZE, "%s\n", nvdumper_set_str);
}

static const struct kobj_attribute nvdumper_attr[] = {
	__ATTR(nvdumper_set, 0644, nvdumper_set_show, nvdumper_set_store),
	__ATTR(nvdumper_prev, 0444, nvdumper_prev_show, NULL),
};

static void nvdumper_sysfs_init(void)
{
	int i, ret = 0;

	nvdumper_kobj = kobject_create_and_add("nvdumper", kernel_kobj);

	if (!nvdumper_kobj) {
		pr_err("unable to create nvdumper kernel object!\n");
		return;
	}

	/* create sysfs */
	for (i = 0; i < ARRAY_SIZE(nvdumper_attr); i++) {
		ret = sysfs_create_file(nvdumper_kobj, &nvdumper_attr[i].attr);
		if (ret)
			pr_err("failed to create %s\n",
			       nvdumper_attr[i].attr.name);
	}

	switch (nvdumper_last_reboot) {
	case NVDUMPER_CLEAN:
		snprintf(nvdumper_set_str, NVDUMPER_SET_STR_LEN, "clean");
		break;
	case NVDUMPER_DIRTY:
		snprintf(nvdumper_set_str, NVDUMPER_SET_STR_LEN, "dirty");
		break;
	case NVDUMPER_DIRTY_DUMP:
		snprintf(nvdumper_set_str, NVDUMPER_SET_STR_LEN, "dirty_dump");
		break;
	default:
		snprintf(nvdumper_set_str, NVDUMPER_SET_STR_LEN, "dirty");
		break;
	}
}

static void nvdumper_sysfs_exit(void)
{
	int i;

	if (!nvdumper_kobj)
		return;

	for (i = 0; i < ARRAY_SIZE(nvdumper_attr); i++)
		sysfs_remove_file(nvdumper_kobj, &nvdumper_attr[i].attr);
}

static int nvdumper_probe(struct platform_device *pdev)
{
	int ret;

	if (!nvdumper_reserved)
		return -ENOTSUPP;

	nvdumper_soc = of_device_get_match_data(&pdev->dev);

	nvdumper_ptr = ioremap_nocache(nvdumper_reserved,
				       NVDUMPER_RESERVED_SIZE);
	if (!nvdumper_ptr) {
		pr_info("nvdumper: failed to ioremap memory at 0x%08lx\n",
			nvdumper_reserved);
		return -EIO;
	}
	ret = register_reboot_notifier(&nvdumper_reboot_notifier);
	if (ret)
		goto err_out1;

	ret = nvdumper_regdump_init();
	if (ret)
		goto err_out2;

	nvdumper_dbg_footprint_init();

	nvdumper_last_reboot = get_dirty_state();
	switch (nvdumper_last_reboot) {
	case NVDUMPER_CLEAN:
		pr_info("nvdumper: last reboot was clean\n");
		break;
	case NVDUMPER_DIRTY:
	case NVDUMPER_DIRTY_DUMP:
	case NVDUMPER_WDT_DUMP:
		pr_info("nvdumper: last reboot was dirty\n");
		break;
	default:
		pr_info("nvdumper: last reboot was unknown\n");
		break;
	}

	nvdumper_sysfs_init();

	set_dirty_state(NVDUMPER_DIRTY);
	return 0;

err_out2:
	unregister_reboot_notifier(&nvdumper_reboot_notifier);
err_out1:
	iounmap(nvdumper_ptr);

	return ret;
}

static int nvdumper_remove(struct platform_device *pdev)
{
	nvdumper_sysfs_exit();
	nvdumper_regdump_exit();
	nvdumper_dbg_footprint_exit();
	unregister_reboot_notifier(&nvdumper_reboot_notifier);
	set_dirty_state(NVDUMPER_CLEAN);
	iounmap(nvdumper_ptr);

	return 0;
}

static const struct nvdumper_soc tegra210_nvdumper_soc = {
	.enable_hw_ram_dump_cntrl = false,
};

static const struct of_device_id of_nvdumper_match[] = {
	{
		.compatible = "nvidia,tegra210-nvdumper",
		.data = &tegra210_nvdumper_soc
	},
	{
		.compatible = "nvidia,tegra186-nvdumper",
		.data = &tegra210_nvdumper_soc
	},
	{ }
};
MODULE_DEVICE_TABLE(of, of_nvdumper_match);

static struct platform_driver nvdumper_driver = {
	.probe		= nvdumper_probe,
	.remove		= nvdumper_remove,
	.driver		= {
		.name	= "tegra-nvdumper",
		.owner	= THIS_MODULE,
		.of_match_table = of_nvdumper_match,
	},
};

builtin_platform_driver(nvdumper_driver);