// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * GPIO driver for Analog Devices ADP5520 MFD PMICs
 *
 * Copyright 2009 Analog Devices Inc.
 */

#include <linux/module.h>
#include <linux/slab.h>
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/platform_device.h>
#include <linux/mfd/adp5520.h>
#include <linux/gpio/driver.h>

struct adp5520_gpio {
        struct device *master;
        struct gpio_chip gpio_chip;
        unsigned char lut[ADP5520_MAXGPIOS];
        unsigned long output;
};

static int adp5520_gpio_get_value(struct gpio_chip *chip, unsigned off)
{
        struct adp5520_gpio *dev;
        uint8_t reg_val;

        dev = gpiochip_get_data(chip);

        /*
         * There are dedicated registers for GPIO IN/OUT.
         * Make sure we return the right value, even when configured as output
         */

        if (test_bit(off, &dev->output))
                adp5520_read(dev->master, ADP5520_GPIO_OUT, &reg_val);
        else
                adp5520_read(dev->master, ADP5520_GPIO_IN, &reg_val);

        return !!(reg_val & dev->lut[off]);
}

static int adp5520_gpio_set_value(struct gpio_chip *chip,
                                  unsigned int off, int val)
{
        struct adp5520_gpio *dev;
        dev = gpiochip_get_data(chip);

        if (val)
                return adp5520_set_bits(dev->master, ADP5520_GPIO_OUT,
                                        dev->lut[off]);
        else
                return adp5520_clr_bits(dev->master, ADP5520_GPIO_OUT,
                                        dev->lut[off]);
}

static int adp5520_gpio_direction_input(struct gpio_chip *chip, unsigned off)
{
        struct adp5520_gpio *dev;
        dev = gpiochip_get_data(chip);

        clear_bit(off, &dev->output);

        return adp5520_clr_bits(dev->master, ADP5520_GPIO_CFG_2,
                                dev->lut[off]);
}

static int adp5520_gpio_direction_output(struct gpio_chip *chip,
                unsigned off, int val)
{
        struct adp5520_gpio *dev;
        int ret = 0;
        dev = gpiochip_get_data(chip);

        set_bit(off, &dev->output);

        if (val)
                ret |= adp5520_set_bits(dev->master, ADP5520_GPIO_OUT,
                                        dev->lut[off]);
        else
                ret |= adp5520_clr_bits(dev->master, ADP5520_GPIO_OUT,
                                        dev->lut[off]);

        ret |= adp5520_set_bits(dev->master, ADP5520_GPIO_CFG_2,
                                        dev->lut[off]);

        return ret;
}

static int adp5520_gpio_probe(struct platform_device *pdev)
{
        struct adp5520_gpio_platform_data *pdata = dev_get_platdata(&pdev->dev);
        struct adp5520_gpio *dev;
        struct gpio_chip *gc;
        int ret, i, gpios;
        unsigned char ctl_mask = 0;

        if (pdata == NULL) {
                dev_err(&pdev->dev, "missing platform data\n");
                return -ENODEV;
        }

        if (pdev->id != ID_ADP5520) {
                dev_err(&pdev->dev, "only ADP5520 supports GPIO\n");
                return -ENODEV;
        }

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

        dev->master = pdev->dev.parent;

        for (gpios = 0, i = 0; i < ADP5520_MAXGPIOS; i++)
                if (pdata->gpio_en_mask & (1 << i))
                        dev->lut[gpios++] = 1 << i;

        if (gpios < 1)
                return -EINVAL;

        gc = &dev->gpio_chip;
        gc->direction_input  = adp5520_gpio_direction_input;
        gc->direction_output = adp5520_gpio_direction_output;
        gc->get = adp5520_gpio_get_value;
        gc->set = adp5520_gpio_set_value;
        gc->can_sleep = true;

        gc->base = pdata->gpio_start;
        gc->ngpio = gpios;
        gc->label = pdev->name;
        gc->owner = THIS_MODULE;

        ret = adp5520_clr_bits(dev->master, ADP5520_GPIO_CFG_1,
                pdata->gpio_en_mask);

        if (pdata->gpio_en_mask & ADP5520_GPIO_C3)
                ctl_mask |= ADP5520_C3_MODE;

        if (pdata->gpio_en_mask & ADP5520_GPIO_R3)
                ctl_mask |= ADP5520_R3_MODE;

        if (ctl_mask)
                ret = adp5520_set_bits(dev->master, ADP5520_LED_CONTROL,
                        ctl_mask);

        ret |= adp5520_set_bits(dev->master, ADP5520_GPIO_PULLUP,
                pdata->gpio_pullup_mask);

        if (ret) {
                dev_err(&pdev->dev, "failed to write\n");
                return ret;
        }

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

static struct platform_driver adp5520_gpio_driver = {
        .driver = {
                .name   = "adp5520-gpio",
        },
        .probe          = adp5520_gpio_probe,
};

module_platform_driver(adp5520_gpio_driver);

MODULE_AUTHOR("Michael Hennerich <michael.hennerich@analog.com>");
MODULE_DESCRIPTION("GPIO ADP5520 Driver");
MODULE_LICENSE("GPL");
MODULE_ALIAS("platform:adp5520-gpio");