// SPDX-License-Identifier: GPL-2.0-only
/*
 * Copyright (C) 2023 Nuvoton Technology Corp.
 * Author: Chi-Fang Li <cfli0@nuvoton.com>
 */

#include <linux/bits.h>
#include <linux/container_of.h>
#include <linux/device.h>
#include <linux/err.h>
#include <linux/io.h>
#include <linux/kernel.h>
#include <linux/of.h>
#include <linux/platform_device.h>
#include <linux/reboot.h>
#include <linux/reset-controller.h>
#include <linux/spinlock.h>
#include <dt-bindings/reset/nuvoton,ma35d1-reset.h>

struct ma35d1_reset_data {
	struct reset_controller_dev rcdev;
	void __iomem *base;
	/* protect registers against concurrent read-modify-write */
	spinlock_t lock;
};

static const struct {
	u32 reg_ofs;
	u32 bit;
} ma35d1_reset_map[] = {
	[MA35D1_RESET_CHIP] =    {0x20, 0},
	[MA35D1_RESET_CA35CR0] = {0x20, 1},
	[MA35D1_RESET_CA35CR1] = {0x20, 2},
	[MA35D1_RESET_CM4] =     {0x20, 3},
	[MA35D1_RESET_PDMA0] =   {0x20, 4},
	[MA35D1_RESET_PDMA1] =   {0x20, 5},
	[MA35D1_RESET_PDMA2] =   {0x20, 6},
	[MA35D1_RESET_PDMA3] =   {0x20, 7},
	[MA35D1_RESET_DISP] =    {0x20, 9},
	[MA35D1_RESET_VCAP0] =   {0x20, 10},
	[MA35D1_RESET_VCAP1] =   {0x20, 11},
	[MA35D1_RESET_GFX] =     {0x20, 12},
	[MA35D1_RESET_VDEC] =    {0x20, 13},
	[MA35D1_RESET_WHC0] =    {0x20, 14},
	[MA35D1_RESET_WHC1] =    {0x20, 15},
	[MA35D1_RESET_GMAC0] =   {0x20, 16},
	[MA35D1_RESET_GMAC1] =   {0x20, 17},
	[MA35D1_RESET_HWSEM] =   {0x20, 18},
	[MA35D1_RESET_EBI] =     {0x20, 19},
	[MA35D1_RESET_HSUSBH0] = {0x20, 20},
	[MA35D1_RESET_HSUSBH1] = {0x20, 21},
	[MA35D1_RESET_HSUSBD] =  {0x20, 22},
	[MA35D1_RESET_USBHL] =   {0x20, 23},
	[MA35D1_RESET_SDH0] =    {0x20, 24},
	[MA35D1_RESET_SDH1] =    {0x20, 25},
	[MA35D1_RESET_NAND] =    {0x20, 26},
	[MA35D1_RESET_GPIO] =    {0x20, 27},
	[MA35D1_RESET_MCTLP] =   {0x20, 28},
	[MA35D1_RESET_MCTLC] =   {0x20, 29},
	[MA35D1_RESET_DDRPUB] =  {0x20, 30},
	[MA35D1_RESET_TMR0] =    {0x24, 2},
	[MA35D1_RESET_TMR1] =    {0x24, 3},
	[MA35D1_RESET_TMR2] =    {0x24, 4},
	[MA35D1_RESET_TMR3] =    {0x24, 5},
	[MA35D1_RESET_I2C0] =    {0x24, 8},
	[MA35D1_RESET_I2C1] =    {0x24, 9},
	[MA35D1_RESET_I2C2] =    {0x24, 10},
	[MA35D1_RESET_I2C3] =    {0x24, 11},
	[MA35D1_RESET_QSPI0] =   {0x24, 12},
	[MA35D1_RESET_SPI0] =    {0x24, 13},
	[MA35D1_RESET_SPI1] =    {0x24, 14},
	[MA35D1_RESET_SPI2] =    {0x24, 15},
	[MA35D1_RESET_UART0] =   {0x24, 16},
	[MA35D1_RESET_UART1] =   {0x24, 17},
	[MA35D1_RESET_UART2] =   {0x24, 18},
	[MA35D1_RESET_UART3] =   {0x24, 19},
	[MA35D1_RESET_UART4] =   {0x24, 20},
	[MA35D1_RESET_UART5] =   {0x24, 21},
	[MA35D1_RESET_UART6] =   {0x24, 22},
	[MA35D1_RESET_UART7] =   {0x24, 23},
	[MA35D1_RESET_CANFD0] =  {0x24, 24},
	[MA35D1_RESET_CANFD1] =  {0x24, 25},
	[MA35D1_RESET_EADC0] =   {0x24, 28},
	[MA35D1_RESET_I2S0] =    {0x24, 29},
	[MA35D1_RESET_SC0] =     {0x28, 0},
	[MA35D1_RESET_SC1] =     {0x28, 1},
	[MA35D1_RESET_QSPI1] =   {0x28, 4},
	[MA35D1_RESET_SPI3] =    {0x28, 6},
	[MA35D1_RESET_EPWM0] =   {0x28, 16},
	[MA35D1_RESET_EPWM1] =   {0x28, 17},
	[MA35D1_RESET_QEI0] =    {0x28, 22},
	[MA35D1_RESET_QEI1] =    {0x28, 23},
	[MA35D1_RESET_ECAP0] =   {0x28, 26},
	[MA35D1_RESET_ECAP1] =   {0x28, 27},
	[MA35D1_RESET_CANFD2] =  {0x28, 28},
	[MA35D1_RESET_ADC0] =    {0x28, 31},
	[MA35D1_RESET_TMR4] =    {0x2C, 0},
	[MA35D1_RESET_TMR5] =    {0x2C, 1},
	[MA35D1_RESET_TMR6] =    {0x2C, 2},
	[MA35D1_RESET_TMR7] =    {0x2C, 3},
	[MA35D1_RESET_TMR8] =    {0x2C, 4},
	[MA35D1_RESET_TMR9] =    {0x2C, 5},
	[MA35D1_RESET_TMR10] =   {0x2C, 6},
	[MA35D1_RESET_TMR11] =   {0x2C, 7},
	[MA35D1_RESET_UART8] =   {0x2C, 8},
	[MA35D1_RESET_UART9] =   {0x2C, 9},
	[MA35D1_RESET_UART10] =  {0x2C, 10},
	[MA35D1_RESET_UART11] =  {0x2C, 11},
	[MA35D1_RESET_UART12] =  {0x2C, 12},
	[MA35D1_RESET_UART13] =  {0x2C, 13},
	[MA35D1_RESET_UART14] =  {0x2C, 14},
	[MA35D1_RESET_UART15] =  {0x2C, 15},
	[MA35D1_RESET_UART16] =  {0x2C, 16},
	[MA35D1_RESET_I2S1] =    {0x2C, 17},
	[MA35D1_RESET_I2C4] =    {0x2C, 18},
	[MA35D1_RESET_I2C5] =    {0x2C, 19},
	[MA35D1_RESET_EPWM2] =   {0x2C, 20},
	[MA35D1_RESET_ECAP2] =   {0x2C, 21},
	[MA35D1_RESET_QEI2] =    {0x2C, 22},
	[MA35D1_RESET_CANFD3] =  {0x2C, 23},
	[MA35D1_RESET_KPI] =     {0x2C, 24},
	[MA35D1_RESET_GIC] =     {0x2C, 28},
	[MA35D1_RESET_SSMCC] =   {0x2C, 30},
	[MA35D1_RESET_SSPCC] =   {0x2C, 31}
};

static int ma35d1_restart_handler(struct sys_off_data *sys_off_data)
{
	struct ma35d1_reset_data *data = sys_off_data->cb_data;
	u32 id = MA35D1_RESET_CHIP;

	writel_relaxed(BIT(ma35d1_reset_map[id].bit),
		       data->base + ma35d1_reset_map[id].reg_ofs);
	return 0;
}

static int ma35d1_reset_update(struct reset_controller_dev *rcdev, unsigned long id, bool assert)
{
	struct ma35d1_reset_data *data = container_of(rcdev, struct ma35d1_reset_data, rcdev);
	unsigned long flags;
	u32 reg;

	if (WARN_ON_ONCE(id >= ARRAY_SIZE(ma35d1_reset_map)))
		return -EINVAL;

	spin_lock_irqsave(&data->lock, flags);
	reg = readl_relaxed(data->base + ma35d1_reset_map[id].reg_ofs);
	if (assert)
		reg |= BIT(ma35d1_reset_map[id].bit);
	else
		reg &= ~(BIT(ma35d1_reset_map[id].bit));
	writel_relaxed(reg, data->base + ma35d1_reset_map[id].reg_ofs);
	spin_unlock_irqrestore(&data->lock, flags);

	return 0;
}

static int ma35d1_reset_assert(struct reset_controller_dev *rcdev, unsigned long id)
{
	return ma35d1_reset_update(rcdev, id, true);
}

static int ma35d1_reset_deassert(struct reset_controller_dev *rcdev, unsigned long id)
{
	return ma35d1_reset_update(rcdev, id, false);
}

static int ma35d1_reset_status(struct reset_controller_dev *rcdev, unsigned long id)
{
	struct ma35d1_reset_data *data = container_of(rcdev, struct ma35d1_reset_data, rcdev);
	u32 reg;

	if (WARN_ON_ONCE(id >= ARRAY_SIZE(ma35d1_reset_map)))
		return -EINVAL;

	reg = readl_relaxed(data->base + ma35d1_reset_map[id].reg_ofs);
	return !!(reg & BIT(ma35d1_reset_map[id].bit));
}

static const struct reset_control_ops ma35d1_reset_ops = {
	.assert = ma35d1_reset_assert,
	.deassert = ma35d1_reset_deassert,
	.status = ma35d1_reset_status,
};

static const struct of_device_id ma35d1_reset_dt_ids[] = {
	{ .compatible = "nuvoton,ma35d1-reset" },
	{ },
};

static int ma35d1_reset_probe(struct platform_device *pdev)
{
	struct ma35d1_reset_data *reset_data;
	struct device *dev = &pdev->dev;
	int err;

	if (!pdev->dev.of_node) {
		dev_err(&pdev->dev, "Device tree node not found\n");
		return -EINVAL;
	}

	reset_data = devm_kzalloc(dev, sizeof(*reset_data), GFP_KERNEL);
	if (!reset_data)
		return -ENOMEM;

	reset_data->base = devm_platform_ioremap_resource(pdev, 0);
	if (IS_ERR(reset_data->base))
		return PTR_ERR(reset_data->base);

	reset_data->rcdev.owner = THIS_MODULE;
	reset_data->rcdev.nr_resets = MA35D1_RESET_COUNT;
	reset_data->rcdev.ops = &ma35d1_reset_ops;
	reset_data->rcdev.of_node = dev->of_node;
	spin_lock_init(&reset_data->lock);

	err = devm_register_sys_off_handler(dev, SYS_OFF_MODE_RESTART, 192,
					    ma35d1_restart_handler, reset_data);
	if (err)
		dev_warn(&pdev->dev, "failed to register restart handler\n");

	return devm_reset_controller_register(dev, &reset_data->rcdev);
}

static struct platform_driver ma35d1_reset_driver = {
	.probe = ma35d1_reset_probe,
	.driver = {
		.name = "ma35d1-reset",
		.of_match_table	= ma35d1_reset_dt_ids,
	},
};

builtin_platform_driver(ma35d1_reset_driver);