// SPDX-License-Identifier: GPL-2.0
// Copyright (C) STMicroelectronics 2019
// Author(s): Fabrice Gasnier <fabrice.gasnier@st.com>.

#include <linux/mfd/syscon.h>
#include <linux/module.h>
#include <linux/of_device.h>
#include <linux/platform_device.h>
#include <linux/regmap.h>
#include <linux/regulator/driver.h>
#include <linux/regulator/of_regulator.h>

/* STM32H7 SYSCFG register */
#define STM32H7_SYSCFG_PMCR		0x04
#define STM32H7_SYSCFG_BOOSTE_MASK	BIT(8)

/* STM32MP1 SYSCFG has set and clear registers */
#define STM32MP1_SYSCFG_PMCSETR		0x04
#define STM32MP1_SYSCFG_PMCCLRR		0x44
#define STM32MP1_SYSCFG_EN_BOOSTER_MASK	BIT(8)

static const struct regulator_ops stm32h7_booster_ops = {
	.enable		= regulator_enable_regmap,
	.disable	= regulator_disable_regmap,
	.is_enabled	= regulator_is_enabled_regmap,
};

static const struct regulator_desc stm32h7_booster_desc = {
	.name = "booster",
	.supply_name = "vdda",
	.n_voltages = 1,
	.type = REGULATOR_VOLTAGE,
	.fixed_uV = 3300000,
	.ramp_delay = 66000, /* up to 50us to stabilize */
	.ops = &stm32h7_booster_ops,
	.enable_reg = STM32H7_SYSCFG_PMCR,
	.enable_mask = STM32H7_SYSCFG_BOOSTE_MASK,
	.owner = THIS_MODULE,
};

static int stm32mp1_booster_enable(struct regulator_dev *rdev)
{
	return regmap_write(rdev->regmap, STM32MP1_SYSCFG_PMCSETR,
			    STM32MP1_SYSCFG_EN_BOOSTER_MASK);
}

static int stm32mp1_booster_disable(struct regulator_dev *rdev)
{
	return regmap_write(rdev->regmap, STM32MP1_SYSCFG_PMCCLRR,
			    STM32MP1_SYSCFG_EN_BOOSTER_MASK);
}

static const struct regulator_ops stm32mp1_booster_ops = {
	.enable		= stm32mp1_booster_enable,
	.disable	= stm32mp1_booster_disable,
	.is_enabled	= regulator_is_enabled_regmap,
};

static const struct regulator_desc stm32mp1_booster_desc = {
	.name = "booster",
	.supply_name = "vdda",
	.n_voltages = 1,
	.type = REGULATOR_VOLTAGE,
	.fixed_uV = 3300000,
	.ramp_delay = 66000,
	.ops = &stm32mp1_booster_ops,
	.enable_reg = STM32MP1_SYSCFG_PMCSETR,
	.enable_mask = STM32MP1_SYSCFG_EN_BOOSTER_MASK,
	.owner = THIS_MODULE,
};

static int stm32_booster_probe(struct platform_device *pdev)
{
	struct device *dev = &pdev->dev;
	struct device_node *np = pdev->dev.of_node;
	struct regulator_config config = { };
	const struct regulator_desc *desc;
	struct regulator_dev *rdev;
	struct regmap *regmap;
	int ret;

	regmap = syscon_regmap_lookup_by_phandle(np, "st,syscfg");
	if (IS_ERR(regmap))
		return PTR_ERR(regmap);

	desc = (const struct regulator_desc *)
		of_match_device(dev->driver->of_match_table, dev)->data;

	config.regmap = regmap;
	config.dev = dev;
	config.of_node = np;
	config.init_data = of_get_regulator_init_data(dev, np, desc);

	rdev = devm_regulator_register(dev, desc, &config);
	if (IS_ERR(rdev)) {
		ret = PTR_ERR(rdev);
		dev_err(dev, "register failed with error %d\n", ret);
		return ret;
	}

	return 0;
}

static const struct of_device_id stm32_booster_of_match[] = {
	{
		.compatible = "st,stm32h7-booster",
		.data = (void *)&stm32h7_booster_desc
	}, {
		.compatible = "st,stm32mp1-booster",
		.data = (void *)&stm32mp1_booster_desc
	}, {
	},
};
MODULE_DEVICE_TABLE(of, stm32_booster_of_match);

static struct platform_driver stm32_booster_driver = {
	.probe = stm32_booster_probe,
	.driver = {
		.name  = "stm32-booster",
		.of_match_table = of_match_ptr(stm32_booster_of_match),
	},
};
module_platform_driver(stm32_booster_driver);

MODULE_LICENSE("GPL v2");
MODULE_AUTHOR("Fabrice Gasnier <fabrice.gasnier@st.com>");
MODULE_DESCRIPTION("STMicroelectronics STM32 booster regulator driver");
MODULE_ALIAS("platform:stm32-booster");