// SPDX-License-Identifier: GPL-2.0-only
/*
 * Copyright (C) 2016 Texas Instruments Incorporated - http://www.ti.com/
 *      Keerthy <j-keerthy@ti.com>
 *
 * Based on the TPS65218 driver
 */

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

#include <linux/mfd/lp873x.h>

#define BITS_PER_GPO            0x4
#define LP873X_GPO_CTRL_OD      0x2

struct lp873x_gpio {
        struct gpio_chip chip;
        struct lp873x *lp873;
};

static int lp873x_gpio_get_direction(struct gpio_chip *chip,
                                     unsigned int offset)
{
        /* This device is output only */
        return GPIO_LINE_DIRECTION_OUT;
}

static int lp873x_gpio_direction_input(struct gpio_chip *chip,
                                       unsigned int offset)
{
        /* This device is output only */
        return -EINVAL;
}

static int lp873x_gpio_direction_output(struct gpio_chip *chip,
                                        unsigned int offset, int value)
{
        struct lp873x_gpio *gpio = gpiochip_get_data(chip);

        /* Set the initial value */
        return regmap_update_bits(gpio->lp873->regmap, LP873X_REG_GPO_CTRL,
                                  BIT(offset * BITS_PER_GPO),
                                  value ? BIT(offset * BITS_PER_GPO) : 0);
}

static int lp873x_gpio_get(struct gpio_chip *chip, unsigned int offset)
{
        struct lp873x_gpio *gpio = gpiochip_get_data(chip);
        int ret, val;

        ret = regmap_read(gpio->lp873->regmap, LP873X_REG_GPO_CTRL, &val);
        if (ret < 0)
                return ret;

        return val & BIT(offset * BITS_PER_GPO);
}

static int lp873x_gpio_set(struct gpio_chip *chip, unsigned int offset,
                           int value)
{
        struct lp873x_gpio *gpio = gpiochip_get_data(chip);

        return regmap_update_bits(gpio->lp873->regmap, LP873X_REG_GPO_CTRL,
                                  BIT(offset * BITS_PER_GPO),
                                  value ? BIT(offset * BITS_PER_GPO) : 0);
}

static int lp873x_gpio_request(struct gpio_chip *gc, unsigned int offset)
{
        struct lp873x_gpio *gpio = gpiochip_get_data(gc);
        int ret;

        switch (offset) {
        case 0:
                /* No MUX Set up Needed for GPO */
                break;
        case 1:
                /* Setup the CLKIN_PIN_SEL MUX to GPO2 */
                ret = regmap_update_bits(gpio->lp873->regmap, LP873X_REG_CONFIG,
                                         LP873X_CONFIG_CLKIN_PIN_SEL, 0);
                if (ret)
                        return ret;

                break;
        default:
                return -EINVAL;
        }

        return 0;
}

static int lp873x_gpio_set_config(struct gpio_chip *gc, unsigned offset,
                                  unsigned long config)
{
        struct lp873x_gpio *gpio = gpiochip_get_data(gc);

        switch (pinconf_to_config_param(config)) {
        case PIN_CONFIG_DRIVE_OPEN_DRAIN:
                return regmap_update_bits(gpio->lp873->regmap,
                                          LP873X_REG_GPO_CTRL,
                                          BIT(offset * BITS_PER_GPO +
                                          LP873X_GPO_CTRL_OD),
                                          BIT(offset * BITS_PER_GPO +
                                          LP873X_GPO_CTRL_OD));

        case PIN_CONFIG_DRIVE_PUSH_PULL:
                return regmap_update_bits(gpio->lp873->regmap,
                                          LP873X_REG_GPO_CTRL,
                                          BIT(offset * BITS_PER_GPO +
                                          LP873X_GPO_CTRL_OD), 0);
        default:
                return -ENOTSUPP;
        }
}

static const struct gpio_chip template_chip = {
        .label                  = "lp873x-gpio",
        .owner                  = THIS_MODULE,
        .request                = lp873x_gpio_request,
        .get_direction          = lp873x_gpio_get_direction,
        .direction_input        = lp873x_gpio_direction_input,
        .direction_output       = lp873x_gpio_direction_output,
        .get                    = lp873x_gpio_get,
        .set                    = lp873x_gpio_set,
        .set_config             = lp873x_gpio_set_config,
        .base                   = -1,
        .ngpio                  = 2,
        .can_sleep              = true,
};

static int lp873x_gpio_probe(struct platform_device *pdev)
{
        struct lp873x_gpio *gpio;
        int ret;

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

        platform_set_drvdata(pdev, gpio);

        gpio->lp873 = dev_get_drvdata(pdev->dev.parent);
        gpio->chip = template_chip;
        gpio->chip.parent = gpio->lp873->dev;

        ret = devm_gpiochip_add_data(&pdev->dev, &gpio->chip, gpio);
        if (ret < 0) {
                dev_err(&pdev->dev, "Could not register gpiochip, %d\n", ret);
                return ret;
        }

        return 0;
}

static const struct platform_device_id lp873x_gpio_id_table[] = {
        { "lp873x-gpio", },
        { /* sentinel */ }
};
MODULE_DEVICE_TABLE(platform, lp873x_gpio_id_table);

static struct platform_driver lp873x_gpio_driver = {
        .driver = {
                .name = "lp873x-gpio",
        },
        .probe = lp873x_gpio_probe,
        .id_table = lp873x_gpio_id_table,
};
module_platform_driver(lp873x_gpio_driver);

MODULE_AUTHOR("Keerthy <j-keerthy@ti.com>");
MODULE_DESCRIPTION("LP873X GPIO driver");
MODULE_LICENSE("GPL v2");