// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * LED driver for Mediatek MT6323 PMIC
 *
 * Copyright (C) 2017 Sean Wang <sean.wang@mediatek.com>
 */
#include <linux/kernel.h>
#include <linux/leds.h>
#include <linux/mfd/mt6323/registers.h>
#include <linux/mfd/mt6397/core.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/platform_device.h>
#include <linux/regmap.h>

/*
 * Register field for TOP_CKPDN0 to enable
 * 32K clock common for LED device.
 */
#define RG_DRV_32K_CK_PDN               BIT(11)
#define RG_DRV_32K_CK_PDN_MASK          BIT(11)

/* 32K/1M/6M clock common for WLED device */
#define RG_VWLED_1M_CK_PDN              BIT(0)
#define RG_VWLED_32K_CK_PDN             BIT(12)
#define RG_VWLED_6M_CK_PDN              BIT(13)

/*
 * Register field for TOP_CKPDN2 to enable
 * individual clock for LED device.
 */
#define RG_ISINK_CK_PDN(i)      BIT(i)
#define RG_ISINK_CK_PDN_MASK(i) BIT(i)

/*
 * Register field for TOP_CKCON1 to select
 * clock source.
 */
#define RG_ISINK_CK_SEL_MASK(i) (BIT(10) << (i))

#define ISINK_CON(r, i)         (r + 0x8 * (i))

/* ISINK_CON0: Register to setup the duty cycle of the blink. */
#define ISINK_DIM_DUTY_MASK     (0x1f << 8)
#define ISINK_DIM_DUTY(i)       (((i) << 8) & ISINK_DIM_DUTY_MASK)

/* ISINK_CON1: Register to setup the period of the blink. */
#define ISINK_DIM_FSEL_MASK     (0xffff)
#define ISINK_DIM_FSEL(i)       ((i) & ISINK_DIM_FSEL_MASK)

/* ISINK_CON2: Register to control the brightness. */
#define ISINK_CH_STEP_SHIFT     12
#define ISINK_CH_STEP_MASK      (0x7 << 12)
#define ISINK_CH_STEP(i)        (((i) << 12) & ISINK_CH_STEP_MASK)
#define ISINK_SFSTR0_TC_MASK    (0x3 << 1)
#define ISINK_SFSTR0_TC(i)      (((i) << 1) & ISINK_SFSTR0_TC_MASK)
#define ISINK_SFSTR0_EN_MASK    BIT(0)
#define ISINK_SFSTR0_EN         BIT(0)

/* Register to LED channel enablement. */
#define ISINK_CH_EN_MASK(i)     BIT(i)
#define ISINK_CH_EN(i)          BIT(i)

#define MAX_SUPPORTED_LEDS              8

struct mt6323_leds;

/**
 * struct mt6323_led - state container for the LED device
 * @id:                 the identifier in MT6323 LED device
 * @parent:             the pointer to MT6323 LED controller
 * @cdev:               LED class device for this LED device
 * @current_brightness: current state of the LED device
 */
struct mt6323_led {
        int                     id;
        struct mt6323_leds      *parent;
        struct led_classdev     cdev;
        enum led_brightness     current_brightness;
};

/**
 * struct mt6323_regs - register spec for the LED device
 * @top_ckpdn:          Offset to ISINK_CKPDN[0..x] registers
 * @num_top_ckpdn:      Number of ISINK_CKPDN registers
 * @top_ckcon:          Offset to ISINK_CKCON[0..x] registers
 * @num_top_ckcon:      Number of ISINK_CKCON registers
 * @isink_con:          Offset to ISINKx_CON[0..x] registers
 * @num_isink_con:      Number of ISINKx_CON registers
 * @isink_max_regs:     Number of ISINK[0..x] registers
 * @isink_en_ctrl:      Offset to ISINK_EN_CTRL register
 * @iwled_en_ctrl:      Offset to IWLED_EN_CTRL register
 */
struct mt6323_regs {
        const u16 *top_ckpdn;
        u8 num_top_ckpdn;
        const u16 *top_ckcon;
        u8 num_top_ckcon;
        const u16 *isink_con;
        u8 num_isink_con;
        u8 isink_max_regs;
        u16 isink_en_ctrl;
        u16 iwled_en_ctrl;
};

/**
 * struct mt6323_hwspec - hardware specific parameters
 * @max_period:         Maximum period for all LEDs
 * @max_leds:           Maximum number of supported LEDs
 * @max_wleds:          Maximum number of WLEDs
 * @max_brightness:     Maximum brightness for all LEDs
 * @unit_duty:          Steps of duty per period
 */
struct mt6323_hwspec {
        u16 max_period;
        u8 max_leds;
        u8 max_wleds;
        u16 max_brightness;
        u16 unit_duty;
};

/**
 * struct mt6323_data - device specific data
 * @regs:               Register spec for this device
 * @spec:               Hardware specific parameters
 */
struct mt6323_data {
        const struct mt6323_regs *regs;
        const struct mt6323_hwspec *spec;
};

/**
 * struct mt6323_leds - state container for holding LED controller
 *                      of the driver
 * @dev:                the device pointer
 * @hw:                 the underlying hardware providing shared
 *                      bus for the register operations
 * @pdata:              device specific data
 * @lock:               the lock among process context
 * @led:                the array that contains the state of individual
 *                      LED device
 */
struct mt6323_leds {
        struct device           *dev;
        struct mt6397_chip      *hw;
        const struct mt6323_data *pdata;
        /* protect among process context */
        struct mutex            lock;
        struct mt6323_led       *led[MAX_SUPPORTED_LEDS];
};

static int mt6323_led_hw_brightness(struct led_classdev *cdev,
                                    enum led_brightness brightness)
{
        struct mt6323_led *led = container_of(cdev, struct mt6323_led, cdev);
        struct mt6323_leds *leds = led->parent;
        const struct mt6323_regs *regs = leds->pdata->regs;
        struct regmap *regmap = leds->hw->regmap;
        u32 con2_mask = 0, con2_val = 0;
        int ret;

        /*
         * Setup current output for the corresponding
         * brightness level.
         */
        con2_mask |= ISINK_CH_STEP_MASK |
                     ISINK_SFSTR0_TC_MASK |
                     ISINK_SFSTR0_EN_MASK;
        con2_val |=  ISINK_CH_STEP(brightness - 1) |
                     ISINK_SFSTR0_TC(2) |
                     ISINK_SFSTR0_EN;

        ret = regmap_update_bits(regmap, ISINK_CON(regs->isink_con[2], led->id),
                                 con2_mask, con2_val);
        return ret;
}

static int mt6323_led_hw_off(struct led_classdev *cdev)
{
        struct mt6323_led *led = container_of(cdev, struct mt6323_led, cdev);
        struct mt6323_leds *leds = led->parent;
        const struct mt6323_regs *regs = leds->pdata->regs;
        struct regmap *regmap = leds->hw->regmap;
        unsigned int status;
        int ret;

        status = ISINK_CH_EN(led->id);
        ret = regmap_update_bits(regmap, regs->isink_en_ctrl,
                                 ISINK_CH_EN_MASK(led->id), ~status);
        if (ret < 0)
                return ret;

        usleep_range(100, 300);
        ret = regmap_update_bits(regmap, regs->top_ckpdn[2],
                                 RG_ISINK_CK_PDN_MASK(led->id),
                                 RG_ISINK_CK_PDN(led->id));
        if (ret < 0)
                return ret;

        return 0;
}

static enum led_brightness
mt6323_get_led_hw_brightness(struct led_classdev *cdev)
{
        struct mt6323_led *led = container_of(cdev, struct mt6323_led, cdev);
        struct mt6323_leds *leds = led->parent;
        const struct mt6323_regs *regs = leds->pdata->regs;
        struct regmap *regmap = leds->hw->regmap;
        unsigned int status;
        int ret;

        ret = regmap_read(regmap, regs->top_ckpdn[2], &status);
        if (ret < 0)
                return ret;

        if (status & RG_ISINK_CK_PDN_MASK(led->id))
                return 0;

        ret = regmap_read(regmap, regs->isink_en_ctrl, &status);
        if (ret < 0)
                return ret;

        if (!(status & ISINK_CH_EN(led->id)))
                return 0;

        ret = regmap_read(regmap, ISINK_CON(regs->isink_con[2], led->id), &status);
        if (ret < 0)
                return ret;

        return  ((status & ISINK_CH_STEP_MASK)
                  >> ISINK_CH_STEP_SHIFT) + 1;
}

static int mt6323_led_hw_on(struct led_classdev *cdev,
                            enum led_brightness brightness)
{
        struct mt6323_led *led = container_of(cdev, struct mt6323_led, cdev);
        struct mt6323_leds *leds = led->parent;
        const struct mt6323_regs *regs = leds->pdata->regs;
        struct regmap *regmap = leds->hw->regmap;
        unsigned int status;
        int ret;

        /*
         * Setup required clock source, enable the corresponding
         * clock and channel and let work with continuous blink as
         * the default.
         */
        ret = regmap_update_bits(regmap, regs->top_ckcon[1],
                                 RG_ISINK_CK_SEL_MASK(led->id), 0);
        if (ret < 0)
                return ret;

        status = RG_ISINK_CK_PDN(led->id);
        ret = regmap_update_bits(regmap, regs->top_ckpdn[2],
                                 RG_ISINK_CK_PDN_MASK(led->id),
                                 ~status);
        if (ret < 0)
                return ret;

        usleep_range(100, 300);

        ret = regmap_update_bits(regmap, regs->isink_en_ctrl,
                                 ISINK_CH_EN_MASK(led->id),
                                 ISINK_CH_EN(led->id));
        if (ret < 0)
                return ret;

        ret = mt6323_led_hw_brightness(cdev, brightness);
        if (ret < 0)
                return ret;

        ret = regmap_update_bits(regmap, ISINK_CON(regs->isink_con[0], led->id),
                                 ISINK_DIM_DUTY_MASK,
                                 ISINK_DIM_DUTY(31));
        if (ret < 0)
                return ret;

        ret = regmap_update_bits(regmap, ISINK_CON(regs->isink_con[1], led->id),
                                 ISINK_DIM_FSEL_MASK,
                                 ISINK_DIM_FSEL(1000));
        if (ret < 0)
                return ret;

        return 0;
}

static int mt6323_led_set_blink(struct led_classdev *cdev,
                                unsigned long *delay_on,
                                unsigned long *delay_off)
{
        struct mt6323_led *led = container_of(cdev, struct mt6323_led, cdev);
        struct mt6323_leds *leds = led->parent;
        const struct mt6323_regs *regs = leds->pdata->regs;
        const struct mt6323_hwspec *spec = leds->pdata->spec;
        struct regmap *regmap = leds->hw->regmap;
        unsigned long period;
        u8 duty_hw;
        int ret;

        /*
         * LED subsystem requires a default user
         * friendly blink pattern for the LED so using
         * 1Hz duty cycle 50% here if without specific
         * value delay_on and delay off being assigned.
         */
        if (!*delay_on && !*delay_off) {
                *delay_on = 500;
                *delay_off = 500;
        }

        /*
         * Units are in ms, if over the hardware able
         * to support, fallback into software blink
         */
        period = *delay_on + *delay_off;

        if (period > spec->max_period)
                return -EINVAL;

        /*
         * Calculate duty_hw based on the percentage of period during
         * which the led is ON.
         */
        duty_hw = DIV_ROUND_CLOSEST(*delay_on * 100000ul, period * spec->unit_duty);

        /* hardware doesn't support zero duty cycle. */
        if (!duty_hw)
                return -EINVAL;

        mutex_lock(&leds->lock);
        /*
         * Set max_brightness as the software blink behavior
         * when no blink brightness.
         */
        if (!led->current_brightness) {
                ret = mt6323_led_hw_on(cdev, cdev->max_brightness);
                if (ret < 0)
                        goto out;
                led->current_brightness = cdev->max_brightness;
        }

        ret = regmap_update_bits(regmap, ISINK_CON(regs->isink_con[0], led->id),
                                 ISINK_DIM_DUTY_MASK,
                                 ISINK_DIM_DUTY(duty_hw - 1));
        if (ret < 0)
                goto out;

        ret = regmap_update_bits(regmap, ISINK_CON(regs->isink_con[1], led->id),
                                 ISINK_DIM_FSEL_MASK,
                                 ISINK_DIM_FSEL(period - 1));
out:
        mutex_unlock(&leds->lock);

        return ret;
}

static int mt6323_led_set_brightness(struct led_classdev *cdev,
                                     enum led_brightness brightness)
{
        struct mt6323_led *led = container_of(cdev, struct mt6323_led, cdev);
        struct mt6323_leds *leds = led->parent;
        int ret;

        mutex_lock(&leds->lock);

        if (!led->current_brightness && brightness) {
                ret = mt6323_led_hw_on(cdev, brightness);
                if (ret < 0)
                        goto out;
        } else if (brightness) {
                ret = mt6323_led_hw_brightness(cdev, brightness);
                if (ret < 0)
                        goto out;
        } else {
                ret = mt6323_led_hw_off(cdev);
                if (ret < 0)
                        goto out;
        }

        led->current_brightness = brightness;
out:
        mutex_unlock(&leds->lock);

        return ret;
}

static int mtk_wled_hw_on(struct led_classdev *cdev)
{
        struct mt6323_led *led = container_of(cdev, struct mt6323_led, cdev);
        struct mt6323_leds *leds = led->parent;
        const struct mt6323_regs *regs = leds->pdata->regs;
        struct regmap *regmap = leds->hw->regmap;
        int ret;

        ret = regmap_clear_bits(regmap, regs->top_ckpdn[0], RG_VWLED_32K_CK_PDN);
        if (ret)
                return ret;

        ret = regmap_clear_bits(regmap, regs->top_ckpdn[0], RG_VWLED_6M_CK_PDN);
        if (ret)
                return ret;

        ret = regmap_clear_bits(regmap, regs->top_ckpdn[0], RG_VWLED_1M_CK_PDN);
        if (ret)
                return ret;

        usleep_range(5000, 6000);

        /* Enable WLED channel pair */
        ret = regmap_set_bits(regmap, regs->iwled_en_ctrl, BIT(led->id));
        if (ret)
                return ret;

        ret = regmap_set_bits(regmap, regs->iwled_en_ctrl, BIT(led->id + 1));
        if (ret)
                return ret;

        return 0;
}

static int mtk_wled_hw_off(struct led_classdev *cdev)
{
        struct mt6323_led *led = container_of(cdev, struct mt6323_led, cdev);
        struct mt6323_leds *leds = led->parent;
        const struct mt6323_regs *regs = leds->pdata->regs;
        struct regmap *regmap = leds->hw->regmap;
        int ret;

        ret = regmap_clear_bits(regmap, regs->iwled_en_ctrl, BIT(led->id + 1));
        if (ret)
                return ret;

        ret = regmap_clear_bits(regmap, regs->iwled_en_ctrl, BIT(led->id));
        if (ret)
                return ret;

        ret = regmap_set_bits(regmap, regs->top_ckpdn[0], RG_VWLED_32K_CK_PDN);
        if (ret)
                return ret;

        ret = regmap_set_bits(regmap, regs->top_ckpdn[0], RG_VWLED_6M_CK_PDN);
        if (ret)
                return ret;

        ret = regmap_set_bits(regmap, regs->top_ckpdn[0], RG_VWLED_1M_CK_PDN);
        if (ret)
                return ret;

        return 0;
}

static enum led_brightness mt6323_get_wled_brightness(struct led_classdev *cdev)
{
        struct mt6323_led *led = container_of(cdev, struct mt6323_led, cdev);
        struct mt6323_leds *leds = led->parent;
        const struct mt6323_regs *regs = leds->pdata->regs;
        struct regmap *regmap = leds->hw->regmap;
        unsigned int status;
        int ret;

        ret = regmap_read(regmap, regs->iwled_en_ctrl, &status);
        if (ret)
                return 0;

        /* Always two channels per WLED */
        status &= BIT(led->id) | BIT(led->id + 1);

        return status ? led->current_brightness : 0;
}

static int mt6323_wled_set_brightness(struct led_classdev *cdev,
                                      enum led_brightness brightness)
{
        struct mt6323_led *led = container_of(cdev, struct mt6323_led, cdev);
        struct mt6323_leds *leds = led->parent;
        int ret = 0;

        mutex_lock(&leds->lock);

        if (brightness) {
                if (!led->current_brightness)
                        ret = mtk_wled_hw_on(cdev);
                if (ret)
                        goto out;
        } else {
                ret = mtk_wled_hw_off(cdev);
                if (ret)
                        goto out;
        }

        led->current_brightness = brightness;
out:
        mutex_unlock(&leds->lock);

        return ret;
}

static int mt6323_led_set_dt_default(struct led_classdev *cdev,
                                     struct device_node *np)
{
        struct mt6323_led *led = container_of(cdev, struct mt6323_led, cdev);
        enum led_default_state state;
        int ret = 0;

        state = led_init_default_state_get(of_fwnode_handle(np));
        switch (state) {
        case LEDS_DEFSTATE_ON:
                ret = mt6323_led_set_brightness(cdev, cdev->max_brightness);
                break;
        case LEDS_DEFSTATE_KEEP:
                ret = mt6323_get_led_hw_brightness(cdev);
                if (ret < 0)
                        return ret;
                led->current_brightness = ret;
                ret = 0;
                break;
        default:
                ret = mt6323_led_set_brightness(cdev, LED_OFF);
        }

        return ret;
}

static int mt6323_led_probe(struct platform_device *pdev)
{
        struct device *dev = &pdev->dev;
        struct device_node *np = dev_of_node(dev);
        struct mt6397_chip *hw = dev_get_drvdata(dev->parent);
        struct mt6323_leds *leds;
        struct mt6323_led *led;
        const struct mt6323_regs *regs;
        const struct mt6323_hwspec *spec;
        int ret;
        unsigned int status;
        u32 reg;
        u8 max_leds;

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

        platform_set_drvdata(pdev, leds);
        leds->dev = dev;
        leds->pdata = device_get_match_data(dev);
        regs = leds->pdata->regs;
        spec = leds->pdata->spec;
        max_leds = spec->max_leds + spec->max_wleds;

        /*
         * leds->hw points to the underlying bus for the register
         * controlled.
         */
        leds->hw = hw;
        mutex_init(&leds->lock);

        status = RG_DRV_32K_CK_PDN;
        ret = regmap_update_bits(leds->hw->regmap, regs->top_ckpdn[0],
                                 RG_DRV_32K_CK_PDN_MASK, ~status);
        if (ret < 0) {
                dev_err(leds->dev,
                        "Failed to update TOP_CKPDN0 Register\n");
                return ret;
        }

        for_each_available_child_of_node_scoped(np, child) {
                struct led_init_data init_data = {};
                bool is_wled;

                ret = of_property_read_u32(child, "reg", &reg);
                if (ret) {
                        dev_err(dev, "Failed to read led 'reg' property\n");
                        return ret;
                }

                if (reg >= max_leds || reg >= MAX_SUPPORTED_LEDS ||
                    leds->led[reg]) {
                        dev_err(dev, "Invalid led reg %u\n", reg);
                        return -EINVAL;
                }

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

                is_wled = of_property_read_bool(child, "mediatek,is-wled");

                leds->led[reg] = led;
                leds->led[reg]->id = reg;
                leds->led[reg]->cdev.max_brightness = spec->max_brightness;

                if (is_wled) {
                        leds->led[reg]->cdev.brightness_set_blocking =
                                                mt6323_wled_set_brightness;
                        leds->led[reg]->cdev.brightness_get =
                                                mt6323_get_wled_brightness;
                } else {
                        leds->led[reg]->cdev.brightness_set_blocking =
                                                mt6323_led_set_brightness;
                        leds->led[reg]->cdev.blink_set = mt6323_led_set_blink;
                        leds->led[reg]->cdev.brightness_get =
                                                mt6323_get_led_hw_brightness;
                }
                leds->led[reg]->parent = leds;

                ret = mt6323_led_set_dt_default(&leds->led[reg]->cdev, child);
                if (ret < 0) {
                        dev_err(leds->dev,
                                "Failed to LED set default from devicetree\n");
                        return ret;
                }

                init_data.fwnode = of_fwnode_handle(child);

                ret = devm_led_classdev_register_ext(dev, &leds->led[reg]->cdev,
                                                     &init_data);
                if (ret) {
                        dev_err(dev, "Failed to register LED: %d\n", ret);
                        return ret;
                }
        }

        return 0;
}

static void mt6323_led_remove(struct platform_device *pdev)
{
        struct mt6323_leds *leds = platform_get_drvdata(pdev);
        const struct mt6323_regs *regs = leds->pdata->regs;
        int i;

        /* Turn the LEDs off on driver removal. */
        for (i = 0 ; leds->led[i] ; i++)
                mt6323_led_hw_off(&leds->led[i]->cdev);

        regmap_update_bits(leds->hw->regmap, regs->top_ckpdn[0],
                           RG_DRV_32K_CK_PDN_MASK,
                           RG_DRV_32K_CK_PDN);

        mutex_destroy(&leds->lock);
}

static const struct mt6323_regs mt6323_registers = {
        .top_ckpdn = (const u16[]){ 0x102, 0x106, 0x10e },
        .num_top_ckpdn = 3,
        .top_ckcon = (const u16[]){ 0x120, 0x126 },
        .num_top_ckcon = 2,
        .isink_con = (const u16[]){ 0x330, 0x332, 0x334 },
        .num_isink_con = 3,
        .isink_max_regs = 4, /* ISINK[0..3] */
        .isink_en_ctrl = 0x356,
};

static const struct mt6323_regs mt6331_registers = {
        .top_ckpdn = (const u16[]){ 0x138, 0x13e, 0x144 },
        .num_top_ckpdn = 3,
        .top_ckcon = (const u16[]){ 0x14c, 0x14a },
        .num_top_ckcon = 2,
        .isink_con = (const u16[]){ 0x40c, 0x40e, 0x410, 0x412, 0x414 },
        .num_isink_con = 5,
        .isink_max_regs = 4, /* ISINK[0..3] */
        .isink_en_ctrl = 0x43a,
};

static const struct mt6323_regs mt6332_registers = {
        .top_ckpdn = (const u16[]){ 0x8094, 0x809a, 0x80a0 },
        .num_top_ckpdn = 3,
        .top_ckcon = (const u16[]){ 0x80a6, 0x80ac },
        .num_top_ckcon = 2,
        .isink_con = (const u16[]){ 0x8cd4 },
        .num_isink_con = 1,
        .isink_max_regs = 12, /* IWLED[0..2, 3..9] */
        .iwled_en_ctrl = 0x8cda,
};

static const struct mt6323_hwspec mt6323_spec = {
        .max_period = 10000,
        .max_leds = 4,
        .max_brightness = 6,
        .unit_duty = 3125,
};

static const struct mt6323_hwspec mt6332_spec = {
        /* There are no LEDs in MT6332. Only WLEDs are present. */
        .max_leds = 0,
        .max_wleds = 1,
        .max_brightness = 1024,
};

static const struct mt6323_data mt6323_pdata = {
        .regs = &mt6323_registers,
        .spec = &mt6323_spec,
};

static const struct mt6323_data mt6331_pdata = {
        .regs = &mt6331_registers,
        .spec = &mt6323_spec,
};

static const struct mt6323_data mt6332_pdata = {
        .regs = &mt6332_registers,
        .spec = &mt6332_spec,
};

static const struct of_device_id mt6323_led_dt_match[] = {
        { .compatible = "mediatek,mt6323-led", .data = &mt6323_pdata},
        { .compatible = "mediatek,mt6331-led", .data = &mt6331_pdata },
        { .compatible = "mediatek,mt6332-led", .data = &mt6332_pdata },
        {},
};
MODULE_DEVICE_TABLE(of, mt6323_led_dt_match);

static struct platform_driver mt6323_led_driver = {
        .probe          = mt6323_led_probe,
        .remove         = mt6323_led_remove,
        .driver         = {
                .name   = "mt6323-led",
                .of_match_table = mt6323_led_dt_match,
        },
};

module_platform_driver(mt6323_led_driver);

MODULE_DESCRIPTION("LED driver for Mediatek MT6323 PMIC");
MODULE_AUTHOR("Sean Wang <sean.wang@mediatek.com>");
MODULE_LICENSE("GPL");