// SPDX-License-Identifier: GPL-2.0
/*
 * GPIO driver for TI TPS65214/TPS65215/TPS65219 PMICs
 *
 * Copyright (C) 2022, 2025 Texas Instruments Incorporated - http://www.ti.com/
 */

#include <linux/bits.h>
#include <linux/gpio/driver.h>
#include <linux/mfd/tps65219.h>
#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/regmap.h>

#define TPS65219_GPIO0_DIR_MASK         BIT(3)
#define TPS65214_GPIO0_DIR_MASK         BIT(1)
#define TPS6521X_GPIO0_OFFSET           2
#define TPS6521X_GPIO0_IDX              0

/*
 * TPS65214 GPIO mapping
 * Linux gpio offset 0 -> GPIO (pin16) -> bit_offset 2
 * Linux gpio offset 1 -> GPO1 (pin9 ) -> bit_offset 0
 *
 * TPS65215 & TPS65219 GPIO mapping
 * Linux gpio offset 0 -> GPIO (pin16) -> bit_offset 2
 * Linux gpio offset 1 -> GPO1 (pin8 ) -> bit_offset 0
 * Linux gpio offset 2 -> GPO2 (pin17) -> bit_offset 1
 */

struct tps65219_gpio {
        int (*change_dir)(struct gpio_chip *gc, unsigned int offset, unsigned int dir);
        struct gpio_chip gpio_chip;
        struct tps65219 *tps;
};

static int tps65214_gpio_get_direction(struct gpio_chip *gc, unsigned int offset)
{
        struct tps65219_gpio *gpio = gpiochip_get_data(gc);
        int ret, val;

        if (offset != TPS6521X_GPIO0_IDX)
                return GPIO_LINE_DIRECTION_OUT;

        ret = regmap_read(gpio->tps->regmap, TPS65219_REG_GENERAL_CONFIG, &val);
        if (ret)
                return ret;

        return !(val & TPS65214_GPIO0_DIR_MASK);
}

static int tps65219_gpio_get_direction(struct gpio_chip *gc, unsigned int offset)
{
        struct tps65219_gpio *gpio = gpiochip_get_data(gc);
        int ret, val;

        if (offset != TPS6521X_GPIO0_IDX)
                return GPIO_LINE_DIRECTION_OUT;

        ret = regmap_read(gpio->tps->regmap, TPS65219_REG_MFP_1_CONFIG, &val);
        if (ret)
                return ret;

        return !!(val & TPS65219_GPIO0_DIR_MASK);
}

static int tps65219_gpio_get(struct gpio_chip *gc, unsigned int offset)
{
        struct tps65219_gpio *gpio = gpiochip_get_data(gc);
        struct device *dev = gpio->tps->dev;
        int ret, val;

        if (offset != TPS6521X_GPIO0_IDX) {
                dev_err(dev, "GPIO%d is output only, cannot get\n", offset);
                return -ENOTSUPP;
        }

        ret = regmap_read(gpio->tps->regmap, TPS65219_REG_MFP_CTRL, &val);
        if (ret)
                return ret;

        ret = !!(val & BIT(TPS65219_MFP_GPIO_STATUS_MASK));
        dev_warn(dev, "GPIO%d = %d, MULTI_DEVICE_ENABLE, not a standard GPIO\n", offset, ret);

        /*
         * Depending on NVM config, return an error if direction is output, otherwise the GPIO0
         * status bit.
         */

        if (tps65219_gpio_get_direction(gc, offset) == GPIO_LINE_DIRECTION_OUT)
                return -ENOTSUPP;

        return ret;
}

static int tps65219_gpio_set(struct gpio_chip *gc, unsigned int offset, int value)
{
        struct tps65219_gpio *gpio = gpiochip_get_data(gc);
        int v, mask, bit;

        bit = (offset == TPS6521X_GPIO0_IDX) ? TPS6521X_GPIO0_OFFSET : offset - 1;

        mask = BIT(bit);
        v = value ? mask : 0;

        return regmap_update_bits(gpio->tps->regmap,
                                  TPS65219_REG_GENERAL_CONFIG, mask, v);
}

static int tps65219_gpio_change_direction(struct gpio_chip *gc, unsigned int offset,
                                          unsigned int direction)
{
        struct tps65219_gpio *gpio = gpiochip_get_data(gc);
        struct device *dev = gpio->tps->dev;

        /*
         * Documentation is stating that GPIO0 direction must not be changed in Linux:
         * Table 8-34. MFP_1_CONFIG(3): MULTI_DEVICE_ENABLE, should only be changed in INITIALIZE
         * state (prior to ON Request).
         * Set statically by NVM, changing direction in application can cause a hang.
         * Below can be used for test purpose only.
         */

#if 0
        int ret = regmap_update_bits(gpio->tps->regmap, TPS65219_REG_MFP_1_CONFIG,
                                     TPS65219_GPIO0_DIR_MASK, direction);
        if (ret) {
                dev_err(dev,
                        "GPIO DEBUG enabled: Fail to change direction to %u for GPIO%d.\n",
                        direction, offset);
                return ret;
        }
#endif

        dev_err(dev,
                "GPIO%d direction set by NVM, change to %u failed, not allowed by specification\n",
                 offset, direction);

        return -ENOTSUPP;
}

static int tps65214_gpio_change_direction(struct gpio_chip *gc, unsigned int offset,
                                          unsigned int direction)
{
        struct tps65219_gpio *gpio = gpiochip_get_data(gc);
        struct device *dev = gpio->tps->dev;
        int val, ret;

        /**
         * Verified if GPIO or GPO in parent function
         * Masked value: 0 = GPIO, 1 = VSEL
         */
        ret = regmap_read(gpio->tps->regmap, TPS65219_REG_MFP_1_CONFIG, &val);
        if (ret)
                return ret;

        ret = !!(val & BIT(TPS65219_GPIO0_DIR_MASK));
        if (ret)
                dev_err(dev, "GPIO%d configured as VSEL, not GPIO\n", offset);

        ret = regmap_update_bits(gpio->tps->regmap, TPS65219_REG_GENERAL_CONFIG,
                                 TPS65214_GPIO0_DIR_MASK, direction);
        if (ret)
                dev_err(dev, "Fail to change direction to %u for GPIO%d.\n", direction, offset);

        return ret;
}

static int tps65219_gpio_direction_input(struct gpio_chip *gc, unsigned int offset)
{
        struct tps65219_gpio *gpio = gpiochip_get_data(gc);
        struct device *dev = gpio->tps->dev;

        if (offset != TPS6521X_GPIO0_IDX) {
                dev_err(dev, "GPIO%d is output only, cannot change to input\n", offset);
                return -ENOTSUPP;
        }

        if (tps65219_gpio_get_direction(gc, offset) == GPIO_LINE_DIRECTION_IN)
                return 0;

        return gpio->change_dir(gc, offset, GPIO_LINE_DIRECTION_IN);
}

static int tps65219_gpio_direction_output(struct gpio_chip *gc, unsigned int offset, int value)
{
        struct tps65219_gpio *gpio = gpiochip_get_data(gc);

        tps65219_gpio_set(gc, offset, value);
        if (offset != TPS6521X_GPIO0_IDX)
                return 0;

        if (tps65219_gpio_get_direction(gc, offset) == GPIO_LINE_DIRECTION_OUT)
                return 0;

        return gpio->change_dir(gc, offset, GPIO_LINE_DIRECTION_OUT);
}

static const struct gpio_chip tps65214_template_chip = {
        .label                  = "tps65214-gpio",
        .owner                  = THIS_MODULE,
        .get_direction          = tps65214_gpio_get_direction,
        .direction_input        = tps65219_gpio_direction_input,
        .direction_output       = tps65219_gpio_direction_output,
        .get                    = tps65219_gpio_get,
        .set                    = tps65219_gpio_set,
        .base                   = -1,
        .ngpio                  = 2,
        .can_sleep              = true,
};

static const struct gpio_chip tps65219_template_chip = {
        .label                  = "tps65219-gpio",
        .owner                  = THIS_MODULE,
        .get_direction          = tps65219_gpio_get_direction,
        .direction_input        = tps65219_gpio_direction_input,
        .direction_output       = tps65219_gpio_direction_output,
        .get                    = tps65219_gpio_get,
        .set                    = tps65219_gpio_set,
        .base                   = -1,
        .ngpio                  = 3,
        .can_sleep              = true,
};

static int tps65219_gpio_probe(struct platform_device *pdev)
{
        enum pmic_id chip = platform_get_device_id(pdev)->driver_data;
        struct tps65219 *tps = dev_get_drvdata(pdev->dev.parent);
        struct tps65219_gpio *gpio;

        gpio = devm_kzalloc(&pdev->dev, sizeof(*gpio), GFP_KERNEL);
        if (!gpio)
                return -ENOMEM;

        if (chip == TPS65214) {
                gpio->gpio_chip = tps65214_template_chip;
                gpio->change_dir = tps65214_gpio_change_direction;
        } else if (chip == TPS65219) {
                gpio->gpio_chip = tps65219_template_chip;
                gpio->change_dir = tps65219_gpio_change_direction;
        } else {
                return -ENODATA;
        }

        gpio->tps = tps;
        gpio->gpio_chip.parent = tps->dev;

        return devm_gpiochip_add_data(&pdev->dev, &gpio->gpio_chip, gpio);
}

static const struct platform_device_id tps6521x_gpio_id_table[] = {
        { "tps65214-gpio", TPS65214 },
        { "tps65219-gpio", TPS65219 },
        { /* sentinel */ }
};
MODULE_DEVICE_TABLE(platform, tps6521x_gpio_id_table);

static struct platform_driver tps65219_gpio_driver = {
        .driver = {
                .name = "tps65219-gpio",
        },
        .probe = tps65219_gpio_probe,
        .id_table = tps6521x_gpio_id_table,
};
module_platform_driver(tps65219_gpio_driver);

MODULE_AUTHOR("Jonathan Cormier <jcormier@criticallink.com>");
MODULE_DESCRIPTION("TPS65214/TPS65215/TPS65219 GPIO driver");
MODULE_LICENSE("GPL");