// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * AXP20x pinctrl and GPIO driver
 *
 * Copyright (C) 2016 Maxime Ripard <maxime.ripard@free-electrons.com>
 * Copyright (C) 2017 Quentin Schulz <quentin.schulz@free-electrons.com>
 */

#include <linux/bitops.h>
#include <linux/device.h>
#include <linux/gpio/driver.h>
#include <linux/init.h>
#include <linux/interrupt.h>
#include <linux/kernel.h>
#include <linux/mfd/axp20x.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/platform_device.h>
#include <linux/regmap.h>
#include <linux/slab.h>

#include <linux/pinctrl/consumer.h>
#include <linux/pinctrl/pinconf-generic.h>
#include <linux/pinctrl/pinctrl.h>
#include <linux/pinctrl/pinmux.h>

#define AXP20X_GPIO_FUNCTIONS           0x7
#define AXP20X_GPIO_FUNCTION_OUT_LOW    0
#define AXP20X_GPIO_FUNCTION_OUT_HIGH   1
#define AXP20X_GPIO_FUNCTION_INPUT      2

#define AXP20X_GPIO3_FUNCTIONS          GENMASK(2, 1)
#define AXP20X_GPIO3_FUNCTION_OUT_LOW   0
#define AXP20X_GPIO3_FUNCTION_OUT_HIGH  2
#define AXP20X_GPIO3_FUNCTION_INPUT     4

#define AXP20X_FUNC_GPIO_OUT            0
#define AXP20X_FUNC_GPIO_IN             1
#define AXP20X_FUNC_LDO                 2
#define AXP20X_FUNC_ADC                 3
#define AXP20X_FUNCS_NB                 4

#define AXP20X_MUX_GPIO_OUT             0
#define AXP20X_MUX_GPIO_IN              BIT(1)
#define AXP20X_MUX_ADC                  BIT(2)

#define AXP813_MUX_ADC                  (BIT(2) | BIT(0))

struct axp20x_pctrl_desc {
        const struct pinctrl_pin_desc   *pins;
        unsigned int                    npins;
        /* Stores the pins supporting LDO function. Bit offset is pin number. */
        u8                              ldo_mask;
        /* Stores the pins supporting ADC function. Bit offset is pin number. */
        u8                              adc_mask;
        u8                              gpio_status_offset;
        u8                              adc_mux;
};

struct axp20x_pinctrl_function {
        const char      *name;
        unsigned int    muxval;
        const char      **groups;
        unsigned int    ngroups;
};

struct axp20x_pctl {
        struct gpio_chip        chip;
        struct regmap           *regmap;
        struct pinctrl_dev                      *pctl_dev;
        struct device                           *dev;
        const struct axp20x_pctrl_desc          *desc;
        struct axp20x_pinctrl_function          funcs[AXP20X_FUNCS_NB];
};

static const struct pinctrl_pin_desc axp209_pins[] = {
        PINCTRL_PIN(0, "GPIO0"),
        PINCTRL_PIN(1, "GPIO1"),
        PINCTRL_PIN(2, "GPIO2"),
        PINCTRL_PIN(3, "GPIO3"),
};

static const struct pinctrl_pin_desc axp22x_pins[] = {
        PINCTRL_PIN(0, "GPIO0"),
        PINCTRL_PIN(1, "GPIO1"),
};

static const struct axp20x_pctrl_desc axp20x_data = {
        .pins   = axp209_pins,
        .npins  = ARRAY_SIZE(axp209_pins),
        .ldo_mask = BIT(0) | BIT(1),
        .adc_mask = BIT(0) | BIT(1),
        .gpio_status_offset = 4,
        .adc_mux = AXP20X_MUX_ADC,
};

static const struct axp20x_pctrl_desc axp22x_data = {
        .pins   = axp22x_pins,
        .npins  = ARRAY_SIZE(axp22x_pins),
        .ldo_mask = BIT(0) | BIT(1),
        .gpio_status_offset = 0,
};

static const struct axp20x_pctrl_desc axp813_data = {
        .pins   = axp22x_pins,
        .npins  = ARRAY_SIZE(axp22x_pins),
        .ldo_mask = BIT(0) | BIT(1),
        .adc_mask = BIT(0),
        .gpio_status_offset = 0,
        .adc_mux = AXP813_MUX_ADC,
};

static int axp20x_gpio_get_reg(unsigned int offset)
{
        switch (offset) {
        case 0:
                return AXP20X_GPIO0_CTRL;
        case 1:
                return AXP20X_GPIO1_CTRL;
        case 2:
                return AXP20X_GPIO2_CTRL;
        }

        return -EINVAL;
}

static int axp20x_gpio_get(struct gpio_chip *chip, unsigned int offset)
{
        struct axp20x_pctl *pctl = gpiochip_get_data(chip);
        unsigned int val;
        int ret;

        /* AXP209 has GPIO3 status sharing the settings register */
        if (offset == 3) {
                ret = regmap_read(pctl->regmap, AXP20X_GPIO3_CTRL, &val);
                if (ret)
                        return ret;
                return !!(val & BIT(0));
        }

        ret = regmap_read(pctl->regmap, AXP20X_GPIO20_SS, &val);
        if (ret)
                return ret;

        return !!(val & BIT(offset + pctl->desc->gpio_status_offset));
}

static int axp20x_gpio_get_direction(struct gpio_chip *chip,
                                     unsigned int offset)
{
        struct axp20x_pctl *pctl = gpiochip_get_data(chip);
        unsigned int val;
        int reg, ret;

        /* AXP209 GPIO3 settings have a different layout */
        if (offset == 3) {
                ret = regmap_read(pctl->regmap, AXP20X_GPIO3_CTRL, &val);
                if (ret)
                        return ret;
                if (val & AXP20X_GPIO3_FUNCTION_INPUT)
                        return GPIO_LINE_DIRECTION_IN;

                return GPIO_LINE_DIRECTION_OUT;
        }

        reg = axp20x_gpio_get_reg(offset);
        if (reg < 0)
                return reg;

        ret = regmap_read(pctl->regmap, reg, &val);
        if (ret)
                return ret;

        /*
         * This shouldn't really happen if the pin is in use already,
         * or if it's not in use yet, it doesn't matter since we're
         * going to change the value soon anyway. Default to output.
         */
        if ((val & AXP20X_GPIO_FUNCTIONS) > 2)
                return GPIO_LINE_DIRECTION_OUT;

        /*
         * The GPIO directions are the three lowest values.
         * 2 is input, 0 and 1 are output
         */
        if (val & 2)
                return GPIO_LINE_DIRECTION_IN;

        return GPIO_LINE_DIRECTION_OUT;
}

static int axp20x_gpio_output(struct gpio_chip *chip, unsigned int offset,
                              int value)
{
        return chip->set(chip, offset, value);
}

static int axp20x_gpio_set(struct gpio_chip *chip, unsigned int offset,
                           int value)
{
        struct axp20x_pctl *pctl = gpiochip_get_data(chip);
        int reg;

        /* AXP209 has GPIO3 status sharing the settings register */
        if (offset == 3)
                return regmap_update_bits(pctl->regmap, AXP20X_GPIO3_CTRL,
                                          AXP20X_GPIO3_FUNCTIONS,
                                          value ?
                                                AXP20X_GPIO3_FUNCTION_OUT_HIGH :
                                                AXP20X_GPIO3_FUNCTION_OUT_LOW);

        reg = axp20x_gpio_get_reg(offset);
        if (reg < 0)
                return reg;

        return regmap_update_bits(pctl->regmap, reg, AXP20X_GPIO_FUNCTIONS,
                                  value ? AXP20X_GPIO_FUNCTION_OUT_HIGH :
                                          AXP20X_GPIO_FUNCTION_OUT_LOW);
}

static int axp20x_pmx_set(struct pinctrl_dev *pctldev, unsigned int offset,
                          u8 config)
{
        struct axp20x_pctl *pctl = pinctrl_dev_get_drvdata(pctldev);
        int reg;

        /* AXP209 GPIO3 settings have a different layout */
        if (offset == 3)
                return regmap_update_bits(pctl->regmap, AXP20X_GPIO3_CTRL,
                                   AXP20X_GPIO3_FUNCTIONS,
                                   config == AXP20X_MUX_GPIO_OUT ? AXP20X_GPIO3_FUNCTION_OUT_LOW :
                                   AXP20X_GPIO3_FUNCTION_INPUT);

        reg = axp20x_gpio_get_reg(offset);
        if (reg < 0)
                return reg;

        return regmap_update_bits(pctl->regmap, reg, AXP20X_GPIO_FUNCTIONS,
                                  config);
}

static int axp20x_pmx_func_cnt(struct pinctrl_dev *pctldev)
{
        struct axp20x_pctl *pctl = pinctrl_dev_get_drvdata(pctldev);

        return ARRAY_SIZE(pctl->funcs);
}

static const char *axp20x_pmx_func_name(struct pinctrl_dev *pctldev,
                                        unsigned int selector)
{
        struct axp20x_pctl *pctl = pinctrl_dev_get_drvdata(pctldev);

        return pctl->funcs[selector].name;
}

static int axp20x_pmx_func_groups(struct pinctrl_dev *pctldev,
                                  unsigned int selector,
                                  const char * const **groups,
                                  unsigned int *num_groups)
{
        struct axp20x_pctl *pctl = pinctrl_dev_get_drvdata(pctldev);

        *groups = pctl->funcs[selector].groups;
        *num_groups = pctl->funcs[selector].ngroups;

        return 0;
}

static int axp20x_pmx_set_mux(struct pinctrl_dev *pctldev,
                              unsigned int function, unsigned int group)
{
        struct axp20x_pctl *pctl = pinctrl_dev_get_drvdata(pctldev);
        unsigned int mask;

        /* Every pin supports GPIO_OUT and GPIO_IN functions */
        if (function <= AXP20X_FUNC_GPIO_IN)
                return axp20x_pmx_set(pctldev, group,
                                      pctl->funcs[function].muxval);

        if (function == AXP20X_FUNC_LDO)
                mask = pctl->desc->ldo_mask;
        else
                mask = pctl->desc->adc_mask;

        if (!(BIT(group) & mask))
                return -EINVAL;

        /*
         * We let the regulator framework handle the LDO muxing as muxing bits
         * are basically also regulators on/off bits. It's better not to enforce
         * any state of the regulator when selecting LDO mux so that we don't
         * interfere with the regulator driver.
         */
        if (function == AXP20X_FUNC_LDO)
                return 0;

        return axp20x_pmx_set(pctldev, group, pctl->funcs[function].muxval);
}

static int axp20x_pmx_gpio_set_direction(struct pinctrl_dev *pctldev,
                                         struct pinctrl_gpio_range *range,
                                         unsigned int offset, bool input)
{
        struct axp20x_pctl *pctl = pinctrl_dev_get_drvdata(pctldev);

        if (input)
                return axp20x_pmx_set(pctldev, offset,
                                      pctl->funcs[AXP20X_FUNC_GPIO_IN].muxval);

        return axp20x_pmx_set(pctldev, offset,
                              pctl->funcs[AXP20X_FUNC_GPIO_OUT].muxval);
}

static const struct pinmux_ops axp20x_pmx_ops = {
        .get_functions_count    = axp20x_pmx_func_cnt,
        .get_function_name      = axp20x_pmx_func_name,
        .get_function_groups    = axp20x_pmx_func_groups,
        .set_mux                = axp20x_pmx_set_mux,
        .gpio_set_direction     = axp20x_pmx_gpio_set_direction,
        .strict                 = true,
};

static int axp20x_groups_cnt(struct pinctrl_dev *pctldev)
{
        struct axp20x_pctl *pctl = pinctrl_dev_get_drvdata(pctldev);

        return pctl->desc->npins;
}

static int axp20x_group_pins(struct pinctrl_dev *pctldev, unsigned int selector,
                             const unsigned int **pins, unsigned int *num_pins)
{
        struct axp20x_pctl *pctl = pinctrl_dev_get_drvdata(pctldev);

        *pins = (unsigned int *)&pctl->desc->pins[selector];
        *num_pins = 1;

        return 0;
}

static const char *axp20x_group_name(struct pinctrl_dev *pctldev,
                                     unsigned int selector)
{
        struct axp20x_pctl *pctl = pinctrl_dev_get_drvdata(pctldev);

        return pctl->desc->pins[selector].name;
}

static const struct pinctrl_ops axp20x_pctrl_ops = {
        .dt_node_to_map         = pinconf_generic_dt_node_to_map_group,
        .dt_free_map            = pinconf_generic_dt_free_map,
        .get_groups_count       = axp20x_groups_cnt,
        .get_group_name         = axp20x_group_name,
        .get_group_pins         = axp20x_group_pins,
};

static int axp20x_funcs_groups_from_mask(struct device *dev, unsigned int mask,
                                          unsigned int mask_len,
                                          struct axp20x_pinctrl_function *func,
                                          const struct pinctrl_pin_desc *pins)
{
        unsigned long int mask_cpy = mask;
        const char **group;
        unsigned int ngroups = hweight8(mask);
        int bit;

        func->ngroups = ngroups;
        if (func->ngroups > 0) {
                func->groups = devm_kcalloc(dev,
                                            ngroups, sizeof(const char *),
                                            GFP_KERNEL);
                if (!func->groups)
                        return -ENOMEM;
                group = func->groups;
                for_each_set_bit(bit, &mask_cpy, mask_len) {
                        *group = pins[bit].name;
                        group++;
                }
        }

        return 0;
}

static int axp20x_build_funcs_groups(struct platform_device *pdev)
{
        struct axp20x_pctl *pctl = platform_get_drvdata(pdev);
        int i, ret, pin, npins = pctl->desc->npins;

        pctl->funcs[AXP20X_FUNC_GPIO_OUT].name = "gpio_out";
        pctl->funcs[AXP20X_FUNC_GPIO_OUT].muxval = AXP20X_MUX_GPIO_OUT;
        pctl->funcs[AXP20X_FUNC_GPIO_IN].name = "gpio_in";
        pctl->funcs[AXP20X_FUNC_GPIO_IN].muxval = AXP20X_MUX_GPIO_IN;
        pctl->funcs[AXP20X_FUNC_LDO].name = "ldo";
        /*
         * Muxval for LDO is useless as we won't use it.
         * See comment in axp20x_pmx_set_mux.
         */
        pctl->funcs[AXP20X_FUNC_ADC].name = "adc";
        pctl->funcs[AXP20X_FUNC_ADC].muxval = pctl->desc->adc_mux;

        /* Every pin supports GPIO_OUT and GPIO_IN functions */
        for (i = 0; i <= AXP20X_FUNC_GPIO_IN; i++) {
                pctl->funcs[i].ngroups = npins;
                pctl->funcs[i].groups = devm_kcalloc(&pdev->dev,
                                                     npins, sizeof(char *),
                                                     GFP_KERNEL);
                if (!pctl->funcs[i].groups)
                        return -ENOMEM;
                for (pin = 0; pin < npins; pin++)
                        pctl->funcs[i].groups[pin] = pctl->desc->pins[pin].name;
        }

        ret = axp20x_funcs_groups_from_mask(&pdev->dev, pctl->desc->ldo_mask,
                                      npins, &pctl->funcs[AXP20X_FUNC_LDO],
                                      pctl->desc->pins);
        if (ret)
                return ret;

        ret = axp20x_funcs_groups_from_mask(&pdev->dev, pctl->desc->adc_mask,
                                      npins, &pctl->funcs[AXP20X_FUNC_ADC],
                                      pctl->desc->pins);
        if (ret)
                return ret;

        return 0;
}

static const struct of_device_id axp20x_pctl_match[] = {
        { .compatible = "x-powers,axp209-gpio", .data = &axp20x_data, },
        { .compatible = "x-powers,axp221-gpio", .data = &axp22x_data, },
        { .compatible = "x-powers,axp813-gpio", .data = &axp813_data, },
        { }
};
MODULE_DEVICE_TABLE(of, axp20x_pctl_match);

static int axp20x_pctl_probe(struct platform_device *pdev)
{
        struct axp20x_dev *axp20x = dev_get_drvdata(pdev->dev.parent);
        struct axp20x_pctl *pctl;
        struct device *dev = &pdev->dev;
        struct pinctrl_desc *pctrl_desc;
        int ret;

        if (!of_device_is_available(pdev->dev.of_node))
                return -ENODEV;

        if (!axp20x) {
                dev_err(&pdev->dev, "Parent drvdata not set\n");
                return -EINVAL;
        }

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

        pctl->chip.base                 = -1;
        pctl->chip.can_sleep            = true;
        pctl->chip.request              = gpiochip_generic_request;
        pctl->chip.free                 = gpiochip_generic_free;
        pctl->chip.parent               = &pdev->dev;
        pctl->chip.label                = dev_name(&pdev->dev);
        pctl->chip.owner                = THIS_MODULE;
        pctl->chip.get                  = axp20x_gpio_get;
        pctl->chip.get_direction        = axp20x_gpio_get_direction;
        pctl->chip.set                  = axp20x_gpio_set;
        pctl->chip.direction_input      = pinctrl_gpio_direction_input;
        pctl->chip.direction_output     = axp20x_gpio_output;

        pctl->desc = of_device_get_match_data(dev);

        pctl->chip.ngpio                = pctl->desc->npins;

        pctl->regmap = axp20x->regmap;
        pctl->dev = &pdev->dev;

        platform_set_drvdata(pdev, pctl);

        ret = axp20x_build_funcs_groups(pdev);
        if (ret) {
                dev_err(&pdev->dev, "failed to build groups\n");
                return ret;
        }

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

        pctrl_desc->name = dev_name(&pdev->dev);
        pctrl_desc->owner = THIS_MODULE;
        pctrl_desc->pins = pctl->desc->pins;
        pctrl_desc->npins = pctl->desc->npins;
        pctrl_desc->pctlops = &axp20x_pctrl_ops;
        pctrl_desc->pmxops = &axp20x_pmx_ops;

        pctl->pctl_dev = devm_pinctrl_register(&pdev->dev, pctrl_desc, pctl);
        if (IS_ERR(pctl->pctl_dev)) {
                dev_err(&pdev->dev, "couldn't register pinctrl driver\n");
                return PTR_ERR(pctl->pctl_dev);
        }

        ret = devm_gpiochip_add_data(&pdev->dev, &pctl->chip, pctl);
        if (ret) {
                dev_err(&pdev->dev, "Failed to register GPIO chip\n");
                return ret;
        }

        ret = gpiochip_add_pin_range(&pctl->chip, dev_name(&pdev->dev),
                                     pctl->desc->pins->number,
                                     pctl->desc->pins->number,
                                     pctl->desc->npins);
        if (ret) {
                dev_err(&pdev->dev, "failed to add pin range\n");
                return ret;
        }

        dev_info(&pdev->dev, "AXP209 pinctrl and GPIO driver loaded\n");

        return 0;
}

static struct platform_driver axp20x_pctl_driver = {
        .probe          = axp20x_pctl_probe,
        .driver = {
                .name           = "axp20x-gpio",
                .of_match_table = axp20x_pctl_match,
        },
};

module_platform_driver(axp20x_pctl_driver);

MODULE_AUTHOR("Maxime Ripard <maxime.ripard@free-electrons.com>");
MODULE_AUTHOR("Quentin Schulz <quentin.schulz@free-electrons.com>");
MODULE_DESCRIPTION("AXP20x PMIC pinctrl and GPIO driver");
MODULE_LICENSE("GPL");