// SPDX-License-Identifier: GPL-2.0-only
/*
 * LED driver for PCA995x I2C LED drivers
 *
 * Copyright 2011 bct electronic GmbH
 * Copyright 2013 Qtechnology/AS
 * Copyright 2022 NXP
 * Copyright 2023 Marek Vasut
 */

#include <linux/i2c.h>
#include <linux/leds.h>
#include <linux/module.h>
#include <linux/mod_devicetable.h>
#include <linux/property.h>
#include <linux/regmap.h>

/* Register definition */
#define PCA995X_MODE1                   0x00
#define PCA995X_MODE2                   0x01
#define PCA995X_LEDOUT0                 0x02

/* Auto-increment disabled. Normal mode */
#define PCA995X_MODE1_CFG               0x00

/* LED select registers determine the source that drives LED outputs */
#define PCA995X_LED_OFF                 0x0
#define PCA995X_LED_ON                  0x1
#define PCA995X_LED_PWM_MODE            0x2
#define PCA995X_LDRX_MASK               0x3
#define PCA995X_LDRX_BITS               2

#define PCA995X_MAX_OUTPUTS             24
#define PCA995X_OUTPUTS_PER_REG         4

#define PCA995X_IREFALL_FULL_CFG        0xFF
#define PCA995X_IREFALL_HALF_CFG        (PCA995X_IREFALL_FULL_CFG / 2)

#define ldev_to_led(c)  container_of(c, struct pca995x_led, ldev)

struct pca995x_chipdef {
        unsigned int num_leds;
        u8 pwm_base;
        u8 irefall;
};

static const struct pca995x_chipdef pca9952_chipdef = {
        .num_leds       = 16,
        .pwm_base       = 0x0a,
        .irefall        = 0x43,
};

static const struct pca995x_chipdef pca9955b_chipdef = {
        .num_leds       = 16,
        .pwm_base       = 0x08,
        .irefall        = 0x45,
};

static const struct pca995x_chipdef pca9956b_chipdef = {
        .num_leds       = 24,
        .pwm_base       = 0x0a,
        .irefall        = 0x40,
};

struct pca995x_led {
        unsigned int led_no;
        struct led_classdev ldev;
        struct pca995x_chip *chip;
};

struct pca995x_chip {
        struct regmap *regmap;
        struct pca995x_led leds[PCA995X_MAX_OUTPUTS];
        const struct pca995x_chipdef *chipdef;
};

static int pca995x_brightness_set(struct led_classdev *led_cdev,
                                  enum led_brightness brightness)
{
        struct pca995x_led *led = ldev_to_led(led_cdev);
        struct pca995x_chip *chip = led->chip;
        const struct pca995x_chipdef *chipdef = chip->chipdef;
        u8 ledout_addr, pwmout_addr;
        int shift, ret;

        pwmout_addr = chipdef->pwm_base + led->led_no;
        ledout_addr = PCA995X_LEDOUT0 + (led->led_no / PCA995X_OUTPUTS_PER_REG);
        shift = PCA995X_LDRX_BITS * (led->led_no % PCA995X_OUTPUTS_PER_REG);

        switch (brightness) {
        case LED_FULL:
                return regmap_update_bits(chip->regmap, ledout_addr,
                                          PCA995X_LDRX_MASK << shift,
                                          PCA995X_LED_ON << shift);
        case LED_OFF:
                return regmap_update_bits(chip->regmap, ledout_addr,
                                          PCA995X_LDRX_MASK << shift, 0);
        default:
                /* Adjust brightness as per user input by changing individual PWM */
                ret = regmap_write(chip->regmap, pwmout_addr, brightness);
                if (ret)
                        return ret;

                /*
                 * Change LDRx configuration to individual brightness via PWM.
                 * LED will stop blinking if it's doing so.
                 */
                return regmap_update_bits(chip->regmap, ledout_addr,
                                          PCA995X_LDRX_MASK << shift,
                                          PCA995X_LED_PWM_MODE << shift);
        }
}

static const struct regmap_config pca995x_regmap = {
        .reg_bits = 8,
        .val_bits = 8,
        .max_register = 0x49,
};

static int pca995x_probe(struct i2c_client *client)
{
        struct fwnode_handle *led_fwnodes[PCA995X_MAX_OUTPUTS] = { 0 };
        struct device *dev = &client->dev;
        const struct pca995x_chipdef *chipdef;
        struct pca995x_chip *chip;
        struct pca995x_led *led;
        int i, j, reg, ret;

        chipdef = device_get_match_data(&client->dev);

        if (!dev_fwnode(dev))
                return -ENODEV;

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

        chip->chipdef = chipdef;
        chip->regmap = devm_regmap_init_i2c(client, &pca995x_regmap);
        if (IS_ERR(chip->regmap))
                return PTR_ERR(chip->regmap);

        i2c_set_clientdata(client, chip);

        device_for_each_child_node_scoped(dev, child) {
                ret = fwnode_property_read_u32(child, "reg", &reg);
                if (ret)
                        return ret;

                if (reg < 0 || reg >= PCA995X_MAX_OUTPUTS || led_fwnodes[reg])
                        return -EINVAL;

                led = &chip->leds[reg];
                led_fwnodes[reg] = fwnode_handle_get(child);
                led->chip = chip;
                led->led_no = reg;
                led->ldev.brightness_set_blocking = pca995x_brightness_set;
                led->ldev.max_brightness = 255;
        }

        for (i = 0; i < PCA995X_MAX_OUTPUTS; i++) {
                struct led_init_data init_data = {};

                if (!led_fwnodes[i])
                        continue;

                init_data.fwnode = led_fwnodes[i];

                ret = devm_led_classdev_register_ext(dev,
                                                     &chip->leds[i].ldev,
                                                     &init_data);
                if (ret < 0) {
                        for (j = i; j < PCA995X_MAX_OUTPUTS; j++)
                                fwnode_handle_put(led_fwnodes[j]);
                        return dev_err_probe(dev, ret,
                                             "Could not register LED %s\n",
                                             chip->leds[i].ldev.name);
                }
        }

        /* Disable LED all-call address and set normal mode */
        ret = regmap_write(chip->regmap, PCA995X_MODE1, PCA995X_MODE1_CFG);
        if (ret)
                return ret;

        /* IREF Output current value for all LEDn outputs */
        return regmap_write(chip->regmap, chipdef->irefall, PCA995X_IREFALL_HALF_CFG);
}

static const struct i2c_device_id pca995x_id[] = {
        { "pca9952", .driver_data = (kernel_ulong_t)&pca9952_chipdef },
        { "pca9955b", .driver_data = (kernel_ulong_t)&pca9955b_chipdef },
        { "pca9956b", .driver_data = (kernel_ulong_t)&pca9956b_chipdef },
        {}
};
MODULE_DEVICE_TABLE(i2c, pca995x_id);

static const struct of_device_id pca995x_of_match[] = {
        { .compatible = "nxp,pca9952", .data = &pca9952_chipdef },
        { .compatible = "nxp,pca9955b", .data = &pca9955b_chipdef },
        { .compatible = "nxp,pca9956b", .data = &pca9956b_chipdef },
        {},
};
MODULE_DEVICE_TABLE(of, pca995x_of_match);

static struct i2c_driver pca995x_driver = {
        .driver = {
                .name = "leds-pca995x",
                .of_match_table = pca995x_of_match,
        },
        .probe = pca995x_probe,
        .id_table = pca995x_id,
};
module_i2c_driver(pca995x_driver);

MODULE_AUTHOR("Isai Gaspar <isaiezequiel.gaspar@nxp.com>");
MODULE_DESCRIPTION("PCA995x LED driver");
MODULE_LICENSE("GPL");