// SPDX-License-Identifier: GPL-2.0-only
/*
 * GPIO support for Cirrus Logic Madera codecs
 *
 * Copyright (C) 2015-2018 Cirrus Logic
 */

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

#include <linux/mfd/madera/core.h>
#include <linux/mfd/madera/pdata.h>
#include <linux/mfd/madera/registers.h>

struct madera_gpio {
        struct madera *madera;
        /* storage space for the gpio_chip we're using */
        struct gpio_chip gpio_chip;
};

static int madera_gpio_get_direction(struct gpio_chip *chip,
                                     unsigned int offset)
{
        struct madera_gpio *madera_gpio = gpiochip_get_data(chip);
        struct madera *madera = madera_gpio->madera;
        unsigned int reg_offset = 2 * offset;
        unsigned int val;
        int ret;

        ret = regmap_read(madera->regmap, MADERA_GPIO1_CTRL_2 + reg_offset,
                          &val);
        if (ret < 0)
                return ret;

        if (val & MADERA_GP1_DIR_MASK)
                return GPIO_LINE_DIRECTION_IN;

        return GPIO_LINE_DIRECTION_OUT;
}

static int madera_gpio_direction_in(struct gpio_chip *chip, unsigned int offset)
{
        struct madera_gpio *madera_gpio = gpiochip_get_data(chip);
        struct madera *madera = madera_gpio->madera;
        unsigned int reg_offset = 2 * offset;

        return regmap_update_bits(madera->regmap,
                                  MADERA_GPIO1_CTRL_2 + reg_offset,
                                  MADERA_GP1_DIR_MASK, MADERA_GP1_DIR);
}

static int madera_gpio_get(struct gpio_chip *chip, unsigned int offset)
{
        struct madera_gpio *madera_gpio = gpiochip_get_data(chip);
        struct madera *madera = madera_gpio->madera;
        unsigned int reg_offset = 2 * offset;
        unsigned int val;
        int ret;

        ret = regmap_read(madera->regmap, MADERA_GPIO1_CTRL_1 + reg_offset,
                          &val);
        if (ret < 0)
                return ret;

        return !!(val & MADERA_GP1_LVL_MASK);
}

static int madera_gpio_direction_out(struct gpio_chip *chip,
                                     unsigned int offset, int value)
{
        struct madera_gpio *madera_gpio = gpiochip_get_data(chip);
        struct madera *madera = madera_gpio->madera;
        unsigned int reg_offset = 2 * offset;
        unsigned int reg_val = value ? MADERA_GP1_LVL : 0;
        int ret;

        ret = regmap_update_bits(madera->regmap,
                                 MADERA_GPIO1_CTRL_2 + reg_offset,
                                 MADERA_GP1_DIR_MASK, 0);
        if (ret < 0)
                return ret;

        return regmap_update_bits(madera->regmap,
                                  MADERA_GPIO1_CTRL_1 + reg_offset,
                                  MADERA_GP1_LVL_MASK, reg_val);
}

static int madera_gpio_set(struct gpio_chip *chip, unsigned int offset,
                           int value)
{
        struct madera_gpio *madera_gpio = gpiochip_get_data(chip);
        struct madera *madera = madera_gpio->madera;
        unsigned int reg_offset = 2 * offset;
        unsigned int reg_val = value ? MADERA_GP1_LVL : 0;

        return regmap_update_bits(madera->regmap,
                                  MADERA_GPIO1_CTRL_1 + reg_offset,
                                  MADERA_GP1_LVL_MASK, reg_val);
}

static const struct gpio_chip madera_gpio_chip = {
        .label                  = "madera",
        .owner                  = THIS_MODULE,
        .request                = gpiochip_generic_request,
        .free                   = gpiochip_generic_free,
        .get_direction          = madera_gpio_get_direction,
        .direction_input        = madera_gpio_direction_in,
        .get                    = madera_gpio_get,
        .direction_output       = madera_gpio_direction_out,
        .set                    = madera_gpio_set,
        .set_config             = gpiochip_generic_config,
        .can_sleep              = true,
};

static int madera_gpio_probe(struct platform_device *pdev)
{
        struct madera *madera = dev_get_drvdata(pdev->dev.parent);
        struct madera_pdata *pdata = &madera->pdata;
        struct madera_gpio *madera_gpio;
        int ret;

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

        madera_gpio->madera = madera;

        /* Construct suitable gpio_chip from the template in madera_gpio_chip */
        madera_gpio->gpio_chip = madera_gpio_chip;
        madera_gpio->gpio_chip.parent = pdev->dev.parent;

        switch (madera->type) {
        case CS47L15:
                madera_gpio->gpio_chip.ngpio = CS47L15_NUM_GPIOS;
                break;
        case CS47L35:
                madera_gpio->gpio_chip.ngpio = CS47L35_NUM_GPIOS;
                break;
        case CS47L85:
        case WM1840:
                madera_gpio->gpio_chip.ngpio = CS47L85_NUM_GPIOS;
                break;
        case CS47L90:
        case CS47L91:
                madera_gpio->gpio_chip.ngpio = CS47L90_NUM_GPIOS;
                break;
        case CS42L92:
        case CS47L92:
        case CS47L93:
                madera_gpio->gpio_chip.ngpio = CS47L92_NUM_GPIOS;
                break;
        default:
                dev_err(&pdev->dev, "Unknown chip variant %d\n", madera->type);
                return -EINVAL;
        }

        /* We want to be usable on systems that don't use devicetree or acpi */
        if (pdata->gpio_base)
                madera_gpio->gpio_chip.base = pdata->gpio_base;
        else
                madera_gpio->gpio_chip.base = -1;

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

        /*
         * This is part of a composite MFD device which can only be used with
         * the corresponding pinctrl driver. On all supported silicon the GPIO
         * to pinctrl mapping is fixed in the silicon, so we register it
         * explicitly instead of requiring a redundant gpio-ranges in the
         * devicetree.
         * In any case we also want to work on systems that don't use devicetree
         * or acpi.
         */
        ret = gpiochip_add_pin_range(&madera_gpio->gpio_chip, "madera-pinctrl",
                                     0, 0, madera_gpio->gpio_chip.ngpio);
        if (ret) {
                dev_dbg(&pdev->dev, "Failed to add pin range (%d)\n", ret);
                return ret;
        }

        return 0;
}

static struct platform_driver madera_gpio_driver = {
        .driver = {
                .name   = "madera-gpio",
        },
        .probe          = madera_gpio_probe,
};

module_platform_driver(madera_gpio_driver);

MODULE_SOFTDEP("pre: pinctrl-madera");
MODULE_DESCRIPTION("GPIO interface for Madera codecs");
MODULE_AUTHOR("Nariman Poushin <nariman@opensource.cirrus.com>");
MODULE_AUTHOR("Richard Fitzgerald <rf@opensource.cirrus.com>");
MODULE_LICENSE("GPL v2");
MODULE_ALIAS("platform:madera-gpio");