// SPDX-License-Identifier: GPL-2.0
// Copyright (c) 2019, Linaro Limited

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

#define WCD_PIN_MASK(p) BIT(p)
#define WCD_REG_DIR_CTL_OFFSET 0x42
#define WCD_REG_VAL_CTL_OFFSET 0x43
#define WCD934X_NPINS           5

struct wcd_gpio_data {
        struct regmap *map;
        struct gpio_chip chip;
};

static int wcd_gpio_get_direction(struct gpio_chip *chip, unsigned int pin)
{
        struct wcd_gpio_data *data = gpiochip_get_data(chip);
        unsigned int value;
        int ret;

        ret = regmap_read(data->map, WCD_REG_DIR_CTL_OFFSET, &value);
        if (ret < 0)
                return ret;

        if (value & WCD_PIN_MASK(pin))
                return GPIO_LINE_DIRECTION_OUT;

        return GPIO_LINE_DIRECTION_IN;
}

static int wcd_gpio_direction_input(struct gpio_chip *chip, unsigned int pin)
{
        struct wcd_gpio_data *data = gpiochip_get_data(chip);

        return regmap_update_bits(data->map, WCD_REG_DIR_CTL_OFFSET,
                                  WCD_PIN_MASK(pin), 0);
}

static int wcd_gpio_direction_output(struct gpio_chip *chip, unsigned int pin,
                                     int val)
{
        struct wcd_gpio_data *data = gpiochip_get_data(chip);
        int ret;

        ret = regmap_update_bits(data->map, WCD_REG_DIR_CTL_OFFSET,
                                 WCD_PIN_MASK(pin), WCD_PIN_MASK(pin));
        if (ret)
                return ret;

        return regmap_update_bits(data->map, WCD_REG_VAL_CTL_OFFSET,
                                  WCD_PIN_MASK(pin),
                                  val ? WCD_PIN_MASK(pin) : 0);
}

static int wcd_gpio_get(struct gpio_chip *chip, unsigned int pin)
{
        struct wcd_gpio_data *data = gpiochip_get_data(chip);
        unsigned int value;

        regmap_read(data->map, WCD_REG_VAL_CTL_OFFSET, &value);

        return !!(value & WCD_PIN_MASK(pin));
}

static int wcd_gpio_set(struct gpio_chip *chip, unsigned int pin, int val)
{
        struct wcd_gpio_data *data = gpiochip_get_data(chip);

        return regmap_update_bits(data->map, WCD_REG_VAL_CTL_OFFSET,
                                  WCD_PIN_MASK(pin),
                                  val ? WCD_PIN_MASK(pin) : 0);
}

static int wcd_gpio_probe(struct platform_device *pdev)
{
        struct device *dev = &pdev->dev;
        struct wcd_gpio_data *data;
        struct gpio_chip *chip;

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

        data->map = dev_get_regmap(dev->parent, NULL);
        if (!data->map) {
                dev_err(dev, "%s: failed to get regmap\n", __func__);
                return  -EINVAL;
        }

        chip = &data->chip;
        chip->direction_input  = wcd_gpio_direction_input;
        chip->direction_output = wcd_gpio_direction_output;
        chip->get_direction = wcd_gpio_get_direction;
        chip->get = wcd_gpio_get;
        chip->set = wcd_gpio_set;
        chip->parent = dev;
        chip->base = -1;
        chip->ngpio = WCD934X_NPINS;
        chip->label = dev_name(dev);
        chip->can_sleep = true;

        return devm_gpiochip_add_data(dev, chip, data);
}

static const struct of_device_id wcd_gpio_of_match[] = {
        { .compatible = "qcom,wcd9340-gpio" },
        { .compatible = "qcom,wcd9341-gpio" },
        { }
};
MODULE_DEVICE_TABLE(of, wcd_gpio_of_match);

static struct platform_driver wcd_gpio_driver = {
        .driver = {
                   .name = "wcd934x-gpio",
                   .of_match_table = wcd_gpio_of_match,
        },
        .probe = wcd_gpio_probe,
};

module_platform_driver(wcd_gpio_driver);
MODULE_DESCRIPTION("Qualcomm Technologies, Inc WCD GPIO control driver");
MODULE_LICENSE("GPL v2");