// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * Kinetic KTD2026/7 RGB/White LED driver with I2C interface
 *
 * Copyright 2023 André Apitzsch <git@apitzsch.eu>
 *
 * Datasheet: https://www.kinet-ic.com/uploads/KTD2026-7-04h.pdf
 */

#include <linux/i2c.h>
#include <linux/led-class-multicolor.h>
#include <linux/module.h>
#include <linux/mutex.h>
#include <linux/of.h>
#include <linux/of_device.h>
#include <linux/regmap.h>
#include <linux/regulator/consumer.h>

#define KTD2026_NUM_LEDS 3
#define KTD2027_NUM_LEDS 4
#define KTD202X_MAX_LEDS 4

/* Register bank */
#define KTD202X_REG_RESET_CONTROL       0x00
#define KTD202X_REG_FLASH_PERIOD        0x01
#define KTD202X_REG_PWM1_TIMER          0x02
#define KTD202X_REG_PWM2_TIMER          0x03
#define KTD202X_REG_CHANNEL_CTRL        0x04
#define KTD202X_REG_TRISE_FALL          0x05
#define KTD202X_REG_LED_IOUT(x)         (0x06 + (x))

/* Register 0 */
#define KTD202X_TIMER_SLOT_CONTROL_TSLOT1       0x00
#define KTD202X_TIMER_SLOT_CONTROL_TSLOT2       0x01
#define KTD202X_TIMER_SLOT_CONTROL_TSLOT3       0x02
#define KTD202X_TIMER_SLOT_CONTROL_TSLOT4       0x03
#define KTD202X_RSTR_RESET                      0x07

#define KTD202X_ENABLE_CTRL_WAKE        0x00 /* SCL High & SDA High */
#define KTD202X_ENABLE_CTRL_SLEEP       0x08 /* SCL High & SDA Toggling */

#define KTD202X_TRISE_FALL_SCALE_NORMAL         0x00
#define KTD202X_TRISE_FALL_SCALE_SLOW_X2        0x20
#define KTD202X_TRISE_FALL_SCALE_SLOW_X4        0x40
#define KTD202X_TRISE_FALL_SCALE_FAST_X8        0x60

/* Register 1 */
#define KTD202X_FLASH_PERIOD_256_MS_LOG_RAMP    0x00

/* Register 2-3 */
#define KTD202X_FLASH_ON_TIME_0_4_PERCENT       0x01

/* Register 4 */
#define KTD202X_CHANNEL_CTRL_MASK(x) (BIT(2 * (x)) | BIT(2 * (x) + 1))
#define KTD202X_CHANNEL_CTRL_OFF 0x00
#define KTD202X_CHANNEL_CTRL_ON(x) BIT(2 * (x))
#define KTD202X_CHANNEL_CTRL_PWM1(x) BIT(2 * (x) + 1)
#define KTD202X_CHANNEL_CTRL_PWM2(x) (BIT(2 * (x)) | BIT(2 * (x) + 1))

/* Register 5 */
#define KTD202X_RAMP_TIMES_2_MS                 0x00

/* Register 6-9 */
#define KTD202X_LED_CURRENT_10_mA               0x4f

#define KTD202X_FLASH_PERIOD_MIN_MS 256
#define KTD202X_FLASH_PERIOD_STEP_MS 128
#define KTD202X_FLASH_PERIOD_MAX_STEPS 126
#define KTD202X_FLASH_ON_MAX 256

#define KTD202X_MAX_BRIGHTNESS 192

static const struct reg_default ktd202x_reg_defaults[] = {
        { KTD202X_REG_RESET_CONTROL, KTD202X_TIMER_SLOT_CONTROL_TSLOT1 |
                KTD202X_ENABLE_CTRL_WAKE | KTD202X_TRISE_FALL_SCALE_NORMAL },
        { KTD202X_REG_FLASH_PERIOD, KTD202X_FLASH_PERIOD_256_MS_LOG_RAMP },
        { KTD202X_REG_PWM1_TIMER, KTD202X_FLASH_ON_TIME_0_4_PERCENT },
        { KTD202X_REG_PWM2_TIMER, KTD202X_FLASH_ON_TIME_0_4_PERCENT },
        { KTD202X_REG_CHANNEL_CTRL, KTD202X_CHANNEL_CTRL_OFF },
        { KTD202X_REG_TRISE_FALL, KTD202X_RAMP_TIMES_2_MS },
        { KTD202X_REG_LED_IOUT(0), KTD202X_LED_CURRENT_10_mA },
        { KTD202X_REG_LED_IOUT(1), KTD202X_LED_CURRENT_10_mA },
        { KTD202X_REG_LED_IOUT(2), KTD202X_LED_CURRENT_10_mA },
        { KTD202X_REG_LED_IOUT(3), KTD202X_LED_CURRENT_10_mA },
};

struct ktd202x_led {
        struct ktd202x *chip;
        union {
                struct led_classdev cdev;
                struct led_classdev_mc mcdev;
        };
        u32 index;
};

struct ktd202x {
        struct mutex mutex;
        struct regulator_bulk_data regulators[2];
        struct device *dev;
        struct regmap *regmap;
        bool enabled;
        unsigned long num_leds;
        struct ktd202x_led leds[] __counted_by(num_leds);
};

static int ktd202x_chip_disable(struct ktd202x *chip)
{
        int ret;

        if (!chip->enabled)
                return 0;

        regmap_write(chip->regmap, KTD202X_REG_RESET_CONTROL, KTD202X_ENABLE_CTRL_SLEEP);

        ret = regulator_bulk_disable(ARRAY_SIZE(chip->regulators), chip->regulators);
        if (ret) {
                dev_err(chip->dev, "Failed to disable regulators: %d\n", ret);
                return ret;
        }

        chip->enabled = false;
        return 0;
}

static int ktd202x_chip_enable(struct ktd202x *chip)
{
        int ret;

        if (chip->enabled)
                return 0;

        ret = regulator_bulk_enable(ARRAY_SIZE(chip->regulators), chip->regulators);
        if (ret) {
                dev_err(chip->dev, "Failed to enable regulators: %d\n", ret);
                return ret;
        }
        chip->enabled = true;

        ret = regmap_write(chip->regmap, KTD202X_REG_RESET_CONTROL, KTD202X_ENABLE_CTRL_WAKE);

        if (ret) {
                dev_err(chip->dev, "Failed to enable the chip: %d\n", ret);
                ktd202x_chip_disable(chip);
        }

        return ret;
}

static bool ktd202x_chip_in_use(struct ktd202x *chip)
{
        int i;

        for (i = 0; i < chip->num_leds; i++) {
                if (chip->leds[i].cdev.brightness)
                        return true;
        }

        return false;
}

static int ktd202x_brightness_set(struct ktd202x_led *led,
                                  struct mc_subled *subleds,
                                  unsigned int num_channels)
{
        bool mode_blink = false;
        int channel;
        int state;
        int ret;
        int i;

        if (ktd202x_chip_in_use(led->chip)) {
                ret = ktd202x_chip_enable(led->chip);
                if (ret)
                        return ret;
        }

        ret = regmap_read(led->chip->regmap, KTD202X_REG_CHANNEL_CTRL, &state);
        if (ret)
                return ret;

        /*
         * In multicolor case, assume blink mode if PWM is set for at least one
         * channel because another channel cannot be in state ON at the same time
         */
        for (i = 0; i < num_channels; i++) {
                int channel_state;

                channel = subleds[i].channel;
                channel_state = (state >> 2 * channel) & KTD202X_CHANNEL_CTRL_MASK(0);
                if (channel_state == KTD202X_CHANNEL_CTRL_OFF)
                        continue;
                mode_blink = channel_state == KTD202X_CHANNEL_CTRL_PWM1(0);
                break;
        }

        for (i = 0; i < num_channels; i++) {
                enum led_brightness brightness;
                int mode;

                brightness = subleds[i].brightness;
                channel = subleds[i].channel;

                if (brightness) {
                        /* Register expects brightness between 0 and MAX_BRIGHTNESS - 1 */
                        ret = regmap_write(led->chip->regmap, KTD202X_REG_LED_IOUT(channel),
                                           brightness - 1);
                        if (ret)
                                return ret;

                        if (mode_blink)
                                mode = KTD202X_CHANNEL_CTRL_PWM1(channel);
                        else
                                mode = KTD202X_CHANNEL_CTRL_ON(channel);
                } else {
                        mode = KTD202X_CHANNEL_CTRL_OFF;
                }
                ret = regmap_update_bits(led->chip->regmap, KTD202X_REG_CHANNEL_CTRL,
                                         KTD202X_CHANNEL_CTRL_MASK(channel), mode);
                if (ret)
                        return ret;
        }

        if (!ktd202x_chip_in_use(led->chip))
                return ktd202x_chip_disable(led->chip);

        return 0;
}

static int ktd202x_brightness_single_set(struct led_classdev *cdev,
                                         enum led_brightness value)
{
        struct ktd202x_led *led = container_of(cdev, struct ktd202x_led, cdev);
        struct mc_subled info;
        int ret;

        cdev->brightness = value;

        mutex_lock(&led->chip->mutex);

        info.brightness = value;
        info.channel = led->index;
        ret = ktd202x_brightness_set(led, &info, 1);

        mutex_unlock(&led->chip->mutex);

        return ret;
}

static int ktd202x_brightness_mc_set(struct led_classdev *cdev,
                                     enum led_brightness value)
{
        struct led_classdev_mc *mc = lcdev_to_mccdev(cdev);
        struct ktd202x_led *led = container_of(mc, struct ktd202x_led, mcdev);
        int ret;

        cdev->brightness = value;

        mutex_lock(&led->chip->mutex);

        led_mc_calc_color_components(mc, value);
        ret = ktd202x_brightness_set(led, mc->subled_info, mc->num_colors);

        mutex_unlock(&led->chip->mutex);

        return ret;
}

static int ktd202x_blink_set(struct ktd202x_led *led, unsigned long *delay_on,
                             unsigned long *delay_off, struct mc_subled *subleds,
                             unsigned int num_channels)
{
        unsigned long delay_total_ms;
        int ret, num_steps, on;
        u8 ctrl_mask = 0;
        u8 ctrl_pwm1 = 0;
        u8 ctrl_on = 0;
        int i;

        mutex_lock(&led->chip->mutex);

        for (i = 0; i < num_channels; i++) {
                int channel = subleds[i].channel;

                ctrl_mask |= KTD202X_CHANNEL_CTRL_MASK(channel);
                ctrl_on |= KTD202X_CHANNEL_CTRL_ON(channel);
                ctrl_pwm1 |= KTD202X_CHANNEL_CTRL_PWM1(channel);
        }

        /* Never off - brightness is already set, disable blinking */
        if (!*delay_off) {
                ret = regmap_update_bits(led->chip->regmap, KTD202X_REG_CHANNEL_CTRL,
                                         ctrl_mask, ctrl_on);
                goto out;
        }

        /* Convert into values the HW will understand. */

        /* Integer representation of time of flash period */
        num_steps = (*delay_on + *delay_off - KTD202X_FLASH_PERIOD_MIN_MS) /
                    KTD202X_FLASH_PERIOD_STEP_MS;
        num_steps = clamp(num_steps, 0, KTD202X_FLASH_PERIOD_MAX_STEPS);

        /* Integer representation of percentage of LED ON time */
        on = (*delay_on * KTD202X_FLASH_ON_MAX) / (*delay_on + *delay_off);

        /* Actually used delay_{on,off} values */
        delay_total_ms = num_steps * KTD202X_FLASH_PERIOD_STEP_MS + KTD202X_FLASH_PERIOD_MIN_MS;
        *delay_on = (delay_total_ms * on) / KTD202X_FLASH_ON_MAX;
        *delay_off = delay_total_ms - *delay_on;

        /* Set timings */
        ret = regmap_write(led->chip->regmap, KTD202X_REG_FLASH_PERIOD, num_steps);
        if (ret)
                goto out;

        ret = regmap_write(led->chip->regmap, KTD202X_REG_PWM1_TIMER, on);
        if (ret)
                goto out;

        ret = regmap_update_bits(led->chip->regmap, KTD202X_REG_CHANNEL_CTRL,
                                 ctrl_mask, ctrl_pwm1);
out:
        mutex_unlock(&led->chip->mutex);
        return ret;
}

static int ktd202x_blink_single_set(struct led_classdev *cdev,
                                    unsigned long *delay_on,
                                    unsigned long *delay_off)
{
        struct ktd202x_led *led = container_of(cdev, struct ktd202x_led, cdev);
        struct mc_subled info;
        int ret;

        if (!cdev->brightness) {
                ret = ktd202x_brightness_single_set(cdev, KTD202X_MAX_BRIGHTNESS);
                if (ret)
                        return ret;
        }

        /* If no blink specified, default to 1 Hz. */
        if (!*delay_off && !*delay_on) {
                *delay_off = 500;
                *delay_on = 500;
        }

        /* Never on - just set to off */
        if (!*delay_on)
                return ktd202x_brightness_single_set(cdev, LED_OFF);

        info.channel = led->index;

        return ktd202x_blink_set(led, delay_on, delay_off, &info, 1);
}

static int ktd202x_blink_mc_set(struct led_classdev *cdev,
                                unsigned long *delay_on,
                                unsigned long *delay_off)
{
        struct led_classdev_mc *mc = lcdev_to_mccdev(cdev);
        struct ktd202x_led *led = container_of(mc, struct ktd202x_led, mcdev);
        int ret;

        if (!cdev->brightness) {
                ret = ktd202x_brightness_mc_set(cdev, KTD202X_MAX_BRIGHTNESS);
                if (ret)
                        return ret;
        }

        /* If no blink specified, default to 1 Hz. */
        if (!*delay_off && !*delay_on) {
                *delay_off = 500;
                *delay_on = 500;
        }

        /* Never on - just set to off */
        if (!*delay_on)
                return ktd202x_brightness_mc_set(cdev, LED_OFF);

        return ktd202x_blink_set(led, delay_on, delay_off, mc->subled_info,
                                 mc->num_colors);
}

static int ktd202x_setup_led_rgb(struct ktd202x *chip, struct fwnode_handle *fwnode,
                                 struct ktd202x_led *led, struct led_init_data *init_data)
{
        struct fwnode_handle *child;
        struct led_classdev *cdev;
        struct mc_subled *info;
        int num_channels;
        int i = 0;

        num_channels = 0;
        fwnode_for_each_child_node(fwnode, child)
                num_channels++;

        if (!num_channels || num_channels > chip->num_leds)
                return -EINVAL;

        info = devm_kcalloc(chip->dev, num_channels, sizeof(*info), GFP_KERNEL);
        if (!info)
                return -ENOMEM;

        fwnode_for_each_child_node(fwnode, child) {
                u32 mono_color;
                u32 reg;
                int ret;

                ret = fwnode_property_read_u32(child, "reg", &reg);
                if (ret != 0 || reg >= chip->num_leds) {
                        dev_err(chip->dev, "invalid 'reg' of %pfw\n", child);
                        fwnode_handle_put(child);
                        return ret;
                }

                ret = fwnode_property_read_u32(child, "color", &mono_color);
                if (ret < 0 && ret != -EINVAL) {
                        dev_err(chip->dev, "failed to parse 'color' of %pfw\n", child);
                        fwnode_handle_put(child);
                        return ret;
                }

                info[i].color_index = mono_color;
                info[i].channel = reg;
                info[i].intensity = KTD202X_MAX_BRIGHTNESS;
                i++;
        }

        led->mcdev.subled_info = info;
        led->mcdev.num_colors = num_channels;

        cdev = &led->mcdev.led_cdev;
        cdev->brightness_set_blocking = ktd202x_brightness_mc_set;
        cdev->blink_set = ktd202x_blink_mc_set;

        return devm_led_classdev_multicolor_register_ext(chip->dev, &led->mcdev, init_data);
}

static int ktd202x_setup_led_single(struct ktd202x *chip, struct fwnode_handle *fwnode,
                                    struct ktd202x_led *led, struct led_init_data *init_data)
{
        struct led_classdev *cdev;
        u32 reg;
        int ret;

        ret = fwnode_property_read_u32(fwnode, "reg", &reg);
        if (ret != 0 || reg >= chip->num_leds) {
                dev_err(chip->dev, "invalid 'reg' of %pfw\n", fwnode);
                return -EINVAL;
        }
        led->index = reg;

        cdev = &led->cdev;
        cdev->brightness_set_blocking = ktd202x_brightness_single_set;
        cdev->blink_set = ktd202x_blink_single_set;

        return devm_led_classdev_register_ext(chip->dev, &led->cdev, init_data);
}

static int ktd202x_add_led(struct ktd202x *chip, struct fwnode_handle *fwnode, unsigned int index)
{
        struct ktd202x_led *led = &chip->leds[index];
        struct led_init_data init_data = {};
        struct led_classdev *cdev;
        u32 color;
        int ret;

        /* Color property is optional in single color case */
        ret = fwnode_property_read_u32(fwnode, "color", &color);
        if (ret < 0 && ret != -EINVAL) {
                dev_err(chip->dev, "failed to parse 'color' of %pfw\n", fwnode);
                return ret;
        }

        led->chip = chip;
        init_data.fwnode = fwnode;

        if (color == LED_COLOR_ID_RGB) {
                cdev = &led->mcdev.led_cdev;
                ret = ktd202x_setup_led_rgb(chip, fwnode, led, &init_data);
        } else {
                cdev = &led->cdev;
                ret = ktd202x_setup_led_single(chip, fwnode, led, &init_data);
        }

        if (ret) {
                dev_err(chip->dev, "unable to register %s\n", cdev->name);
                return ret;
        }

        cdev->max_brightness = KTD202X_MAX_BRIGHTNESS;

        return 0;
}

static int ktd202x_probe_fw(struct ktd202x *chip)
{
        struct device *dev = chip->dev;
        int count;
        int i = 0;

        count = device_get_child_node_count(dev);
        if (!count || count > chip->num_leds)
                return -EINVAL;

        regmap_write(chip->regmap, KTD202X_REG_RESET_CONTROL, KTD202X_RSTR_RESET);

        /* Allow the device to execute the complete reset */
        usleep_range(200, 300);

        device_for_each_child_node_scoped(dev, child) {
                int ret = ktd202x_add_led(chip, child, i);

                if (ret)
                        return ret;

                i++;
        }

        return 0;
}

static const struct regmap_config ktd202x_regmap_config = {
        .reg_bits = 8,
        .val_bits = 8,
        .max_register = 0x09,
        .cache_type = REGCACHE_FLAT,
        .reg_defaults = ktd202x_reg_defaults,
        .num_reg_defaults = ARRAY_SIZE(ktd202x_reg_defaults),
};

static int ktd202x_probe(struct i2c_client *client)
{
        struct device *dev = &client->dev;
        struct ktd202x *chip;
        int count;
        int ret;

        count = device_get_child_node_count(dev);
        if (!count || count > KTD202X_MAX_LEDS)
                return dev_err_probe(dev, -EINVAL, "Incorrect number of leds (%d)", count);

        chip = devm_kzalloc(dev, struct_size(chip, leds, count), GFP_KERNEL);
        if (!chip)
                return -ENOMEM;

        chip->dev = dev;
        i2c_set_clientdata(client, chip);

        chip->regmap = devm_regmap_init_i2c(client, &ktd202x_regmap_config);
        if (IS_ERR(chip->regmap)) {
                ret = dev_err_probe(dev, PTR_ERR(chip->regmap),
                                    "Failed to allocate register map.\n");
                return ret;
        }

        ret = devm_mutex_init(dev, &chip->mutex);
        if (ret)
                return ret;

        chip->num_leds = (unsigned long)i2c_get_match_data(client);

        chip->regulators[0].supply = "vin";
        chip->regulators[1].supply = "vio";
        ret = devm_regulator_bulk_get(dev, ARRAY_SIZE(chip->regulators), chip->regulators);
        if (ret < 0) {
                dev_err_probe(dev, ret, "Failed to request regulators.\n");
                return ret;
        }

        ret = regulator_bulk_enable(ARRAY_SIZE(chip->regulators), chip->regulators);
        if (ret) {
                dev_err_probe(dev, ret, "Failed to enable regulators.\n");
                return ret;
        }

        ret = ktd202x_probe_fw(chip);
        if (ret < 0) {
                regulator_bulk_disable(ARRAY_SIZE(chip->regulators), chip->regulators);
                return ret;
        }

        ret = regulator_bulk_disable(ARRAY_SIZE(chip->regulators), chip->regulators);
        if (ret) {
                dev_err_probe(dev, ret, "Failed to disable regulators.\n");
                return ret;
        }

        return 0;
}

static void ktd202x_remove(struct i2c_client *client)
{
        struct ktd202x *chip = i2c_get_clientdata(client);

        ktd202x_chip_disable(chip);
}

static void ktd202x_shutdown(struct i2c_client *client)
{
        struct ktd202x *chip = i2c_get_clientdata(client);

        /* Reset registers to make sure all LEDs are off before shutdown */
        regmap_write(chip->regmap, KTD202X_REG_RESET_CONTROL, KTD202X_RSTR_RESET);
}

static const struct i2c_device_id ktd202x_id[] = {
        {"ktd2026", KTD2026_NUM_LEDS},
        {"ktd2027", KTD2027_NUM_LEDS},
        {}
};
MODULE_DEVICE_TABLE(i2c, ktd202x_id);

static const struct of_device_id ktd202x_match_table[] = {
        { .compatible = "kinetic,ktd2026", .data = (void *)KTD2026_NUM_LEDS },
        { .compatible = "kinetic,ktd2027", .data = (void *)KTD2027_NUM_LEDS },
        {}
};
MODULE_DEVICE_TABLE(of, ktd202x_match_table);

static struct i2c_driver ktd202x_driver = {
        .driver = {
                .name = "leds-ktd202x",
                .of_match_table = ktd202x_match_table,
        },
        .probe = ktd202x_probe,
        .remove = ktd202x_remove,
        .shutdown = ktd202x_shutdown,
        .id_table = ktd202x_id,
};
module_i2c_driver(ktd202x_driver);

MODULE_AUTHOR("André Apitzsch <git@apitzsch.eu>");
MODULE_DESCRIPTION("Kinetic KTD2026/7 LED driver");
MODULE_LICENSE("GPL");