// SPDX-License-Identifier: GPL-2.0-only
/*
 * Copyright (C) 2011 ST-Ericsson SA.
 * Copyright (C) 2009 Motorola, Inc.
 *
 * Simple driver for National Semiconductor LM3530 Backlight driver chip
 *
 * Author: Shreshtha Kumar SAHU <shreshthakumar.sahu@stericsson.com>
 * based on leds-lm3530.c by Dan Murphy <D.Murphy@motorola.com>
 */

#include <linux/i2c.h>
#include <linux/leds.h>
#include <linux/slab.h>
#include <linux/platform_device.h>
#include <linux/input.h>
#include <linux/led-lm3530.h>
#include <linux/types.h>
#include <linux/regulator/consumer.h>
#include <linux/module.h>

#define LM3530_LED_DEV "lcd-backlight"
#define LM3530_NAME "lm3530-led"

#define LM3530_GEN_CONFIG               0x10
#define LM3530_ALS_CONFIG               0x20
#define LM3530_BRT_RAMP_RATE            0x30
#define LM3530_ALS_IMP_SELECT           0x41
#define LM3530_BRT_CTRL_REG             0xA0
#define LM3530_ALS_ZB0_REG              0x60
#define LM3530_ALS_ZB1_REG              0x61
#define LM3530_ALS_ZB2_REG              0x62
#define LM3530_ALS_ZB3_REG              0x63
#define LM3530_ALS_Z0T_REG              0x70
#define LM3530_ALS_Z1T_REG              0x71
#define LM3530_ALS_Z2T_REG              0x72
#define LM3530_ALS_Z3T_REG              0x73
#define LM3530_ALS_Z4T_REG              0x74
#define LM3530_REG_MAX                  14

/* General Control Register */
#define LM3530_EN_I2C_SHIFT             (0)
#define LM3530_RAMP_LAW_SHIFT           (1)
#define LM3530_MAX_CURR_SHIFT           (2)
#define LM3530_EN_PWM_SHIFT             (5)
#define LM3530_PWM_POL_SHIFT            (6)
#define LM3530_EN_PWM_SIMPLE_SHIFT      (7)

#define LM3530_ENABLE_I2C               (1 << LM3530_EN_I2C_SHIFT)
#define LM3530_ENABLE_PWM               (1 << LM3530_EN_PWM_SHIFT)
#define LM3530_POL_LOW                  (1 << LM3530_PWM_POL_SHIFT)
#define LM3530_ENABLE_PWM_SIMPLE        (1 << LM3530_EN_PWM_SIMPLE_SHIFT)

/* ALS Config Register Options */
#define LM3530_ALS_AVG_TIME_SHIFT       (0)
#define LM3530_EN_ALS_SHIFT             (3)
#define LM3530_ALS_SEL_SHIFT            (5)

#define LM3530_ENABLE_ALS               (3 << LM3530_EN_ALS_SHIFT)

/* Brightness Ramp Rate Register */
#define LM3530_BRT_RAMP_FALL_SHIFT      (0)
#define LM3530_BRT_RAMP_RISE_SHIFT      (3)

/* ALS Resistor Select */
#define LM3530_ALS1_IMP_SHIFT           (0)
#define LM3530_ALS2_IMP_SHIFT           (4)

/* Zone Boundary Register defaults */
#define LM3530_ALS_ZB_MAX               (4)
#define LM3530_ALS_WINDOW_mV            (1000)
#define LM3530_ALS_OFFSET_mV            (4)

/* Zone Target Register defaults */
#define LM3530_DEF_ZT_0                 (0x7F)
#define LM3530_DEF_ZT_1                 (0x66)
#define LM3530_DEF_ZT_2                 (0x4C)
#define LM3530_DEF_ZT_3                 (0x33)
#define LM3530_DEF_ZT_4                 (0x19)

/* 7 bits are used for the brightness : LM3530_BRT_CTRL_REG */
#define MAX_BRIGHTNESS                  (127)

struct lm3530_mode_map {
        const char *mode;
        enum lm3530_mode mode_val;
};

static struct lm3530_mode_map mode_map[] = {
        { "man", LM3530_BL_MODE_MANUAL },
        { "als", LM3530_BL_MODE_ALS },
        { "pwm", LM3530_BL_MODE_PWM },
};

/**
 * struct lm3530_data
 * @led_dev: led class device
 * @client: i2c client
 * @pdata: LM3530 platform data
 * @mode: mode of operation - manual, ALS, PWM
 * @regulator: regulator
 * @brightness: previous brightness value
 * @enable: regulator is enabled
 */
struct lm3530_data {
        struct led_classdev led_dev;
        struct i2c_client *client;
        struct lm3530_platform_data *pdata;
        enum lm3530_mode mode;
        struct regulator *regulator;
        enum led_brightness brightness;
        bool enable;
};

/*
 * struct lm3530_als_data
 * @config  : value of ALS configuration register
 * @imp_sel : value of ALS resistor select register
 * @zone    : values of ALS ZB(Zone Boundary) registers
 */
struct lm3530_als_data {
        u8 config;
        u8 imp_sel;
        u8 zones[LM3530_ALS_ZB_MAX];
};

static const u8 lm3530_reg[LM3530_REG_MAX] = {
        LM3530_GEN_CONFIG,
        LM3530_ALS_CONFIG,
        LM3530_BRT_RAMP_RATE,
        LM3530_ALS_IMP_SELECT,
        LM3530_BRT_CTRL_REG,
        LM3530_ALS_ZB0_REG,
        LM3530_ALS_ZB1_REG,
        LM3530_ALS_ZB2_REG,
        LM3530_ALS_ZB3_REG,
        LM3530_ALS_Z0T_REG,
        LM3530_ALS_Z1T_REG,
        LM3530_ALS_Z2T_REG,
        LM3530_ALS_Z3T_REG,
        LM3530_ALS_Z4T_REG,
};

static int lm3530_get_mode_from_str(const char *str)
{
        int i;

        for (i = 0; i < ARRAY_SIZE(mode_map); i++)
                if (sysfs_streq(str, mode_map[i].mode))
                        return mode_map[i].mode_val;

        return -EINVAL;
}

static void lm3530_als_configure(struct lm3530_platform_data *pdata,
                                struct lm3530_als_data *als)
{
        int i;
        u32 als_vmin, als_vmax, als_vstep;

        if (pdata->als_vmax == 0) {
                pdata->als_vmin = 0;
                pdata->als_vmax = LM3530_ALS_WINDOW_mV;
        }

        als_vmin = pdata->als_vmin;
        als_vmax = pdata->als_vmax;

        if ((als_vmax - als_vmin) > LM3530_ALS_WINDOW_mV)
                pdata->als_vmax = als_vmax = als_vmin + LM3530_ALS_WINDOW_mV;

        /* n zone boundary makes n+1 zones */
        als_vstep = (als_vmax - als_vmin) / (LM3530_ALS_ZB_MAX + 1);

        for (i = 0; i < LM3530_ALS_ZB_MAX; i++)
                als->zones[i] = (((als_vmin + LM3530_ALS_OFFSET_mV) +
                        als_vstep + (i * als_vstep)) * LED_FULL) / 1000;

        als->config =
                (pdata->als_avrg_time << LM3530_ALS_AVG_TIME_SHIFT) |
                (LM3530_ENABLE_ALS) |
                (pdata->als_input_mode << LM3530_ALS_SEL_SHIFT);

        als->imp_sel =
                (pdata->als1_resistor_sel << LM3530_ALS1_IMP_SHIFT) |
                (pdata->als2_resistor_sel << LM3530_ALS2_IMP_SHIFT);
}

static int lm3530_led_enable(struct lm3530_data *drvdata)
{
        int ret;

        if (drvdata->enable)
                return 0;

        ret = regulator_enable(drvdata->regulator);
        if (ret) {
                dev_err(drvdata->led_dev.dev, "Failed to enable vin:%d\n", ret);
                return ret;
        }

        drvdata->enable = true;
        return 0;
}

static void lm3530_led_disable(struct lm3530_data *drvdata)
{
        int ret;

        if (!drvdata->enable)
                return;

        ret = regulator_disable(drvdata->regulator);
        if (ret) {
                dev_err(drvdata->led_dev.dev, "Failed to disable vin:%d\n",
                        ret);
                return;
        }

        drvdata->enable = false;
}

static int lm3530_init_registers(struct lm3530_data *drvdata)
{
        int ret = 0;
        int i;
        u8 gen_config;
        u8 brt_ramp;
        u8 brightness;
        u8 reg_val[LM3530_REG_MAX];
        struct lm3530_platform_data *pdata = drvdata->pdata;
        struct i2c_client *client = drvdata->client;
        struct lm3530_pwm_data *pwm = &pdata->pwm_data;
        struct lm3530_als_data als;

        memset(&als, 0, sizeof(struct lm3530_als_data));

        gen_config = (pdata->brt_ramp_law << LM3530_RAMP_LAW_SHIFT) |
                        ((pdata->max_current & 7) << LM3530_MAX_CURR_SHIFT);

        switch (drvdata->mode) {
        case LM3530_BL_MODE_MANUAL:
                gen_config |= LM3530_ENABLE_I2C;
                break;
        case LM3530_BL_MODE_ALS:
                gen_config |= LM3530_ENABLE_I2C;
                lm3530_als_configure(pdata, &als);
                break;
        case LM3530_BL_MODE_PWM:
                gen_config |= LM3530_ENABLE_PWM | LM3530_ENABLE_PWM_SIMPLE |
                              (pdata->pwm_pol_hi << LM3530_PWM_POL_SHIFT);
                break;
        }

        brt_ramp = (pdata->brt_ramp_fall << LM3530_BRT_RAMP_FALL_SHIFT) |
                        (pdata->brt_ramp_rise << LM3530_BRT_RAMP_RISE_SHIFT);

        if (drvdata->brightness)
                brightness = drvdata->brightness;
        else
                brightness = drvdata->brightness = pdata->brt_val;

        if (brightness > drvdata->led_dev.max_brightness)
                brightness = drvdata->led_dev.max_brightness;

        reg_val[0] = gen_config;        /* LM3530_GEN_CONFIG */
        reg_val[1] = als.config;        /* LM3530_ALS_CONFIG */
        reg_val[2] = brt_ramp;          /* LM3530_BRT_RAMP_RATE */
        reg_val[3] = als.imp_sel;       /* LM3530_ALS_IMP_SELECT */
        reg_val[4] = brightness;        /* LM3530_BRT_CTRL_REG */
        reg_val[5] = als.zones[0];      /* LM3530_ALS_ZB0_REG */
        reg_val[6] = als.zones[1];      /* LM3530_ALS_ZB1_REG */
        reg_val[7] = als.zones[2];      /* LM3530_ALS_ZB2_REG */
        reg_val[8] = als.zones[3];      /* LM3530_ALS_ZB3_REG */
        reg_val[9] = LM3530_DEF_ZT_0;   /* LM3530_ALS_Z0T_REG */
        reg_val[10] = LM3530_DEF_ZT_1;  /* LM3530_ALS_Z1T_REG */
        reg_val[11] = LM3530_DEF_ZT_2;  /* LM3530_ALS_Z2T_REG */
        reg_val[12] = LM3530_DEF_ZT_3;  /* LM3530_ALS_Z3T_REG */
        reg_val[13] = LM3530_DEF_ZT_4;  /* LM3530_ALS_Z4T_REG */

        ret = lm3530_led_enable(drvdata);
        if (ret)
                return ret;

        for (i = 0; i < LM3530_REG_MAX; i++) {
                /* do not update brightness register when pwm mode */
                if (lm3530_reg[i] == LM3530_BRT_CTRL_REG &&
                    drvdata->mode == LM3530_BL_MODE_PWM) {
                        if (pwm->pwm_set_intensity)
                                pwm->pwm_set_intensity(reg_val[i],
                                        drvdata->led_dev.max_brightness);
                        continue;
                }

                ret = i2c_smbus_write_byte_data(client,
                                lm3530_reg[i], reg_val[i]);
                if (ret)
                        break;
        }

        return ret;
}

static void lm3530_brightness_set(struct led_classdev *led_cdev,
                                     enum led_brightness brt_val)
{
        int err;
        struct lm3530_data *drvdata =
            container_of(led_cdev, struct lm3530_data, led_dev);
        struct lm3530_platform_data *pdata = drvdata->pdata;
        struct lm3530_pwm_data *pwm = &pdata->pwm_data;
        u8 max_brightness = led_cdev->max_brightness;

        switch (drvdata->mode) {
        case LM3530_BL_MODE_MANUAL:

                if (!drvdata->enable) {
                        err = lm3530_init_registers(drvdata);
                        if (err) {
                                dev_err(&drvdata->client->dev,
                                        "Register Init failed: %d\n", err);
                                break;
                        }
                }

                /* set the brightness in brightness control register*/
                err = i2c_smbus_write_byte_data(drvdata->client,
                                LM3530_BRT_CTRL_REG, brt_val);
                if (err)
                        dev_err(&drvdata->client->dev,
                                "Unable to set brightness: %d\n", err);
                else
                        drvdata->brightness = brt_val;

                if (brt_val == 0)
                        lm3530_led_disable(drvdata);
                break;
        case LM3530_BL_MODE_ALS:
                break;
        case LM3530_BL_MODE_PWM:
                if (pwm->pwm_set_intensity)
                        pwm->pwm_set_intensity(brt_val, max_brightness);
                break;
        default:
                break;
        }
}

static ssize_t mode_show(struct device *dev,
                         struct device_attribute *attr, char *buf)
{
        struct led_classdev *led_cdev = dev_get_drvdata(dev);
        struct lm3530_data *drvdata;
        int i, len = 0;

        drvdata = container_of(led_cdev, struct lm3530_data, led_dev);
        for (i = 0; i < ARRAY_SIZE(mode_map); i++)
                if (drvdata->mode == mode_map[i].mode_val)
                        len += sprintf(buf + len, "[%s] ", mode_map[i].mode);
                else
                        len += sprintf(buf + len, "%s ", mode_map[i].mode);

        len += sprintf(buf + len, "\n");

        return len;
}

static ssize_t mode_store(struct device *dev, struct device_attribute
                          *attr, const char *buf, size_t size)
{
        struct led_classdev *led_cdev = dev_get_drvdata(dev);
        struct lm3530_data *drvdata;
        struct lm3530_pwm_data *pwm;
        u8 max_brightness;
        int mode, err;

        drvdata = container_of(led_cdev, struct lm3530_data, led_dev);
        pwm = &drvdata->pdata->pwm_data;
        max_brightness = led_cdev->max_brightness;
        mode = lm3530_get_mode_from_str(buf);
        if (mode < 0) {
                dev_err(dev, "Invalid mode\n");
                return mode;
        }

        drvdata->mode = mode;

        /* set pwm to low if unnecessary */
        if (mode != LM3530_BL_MODE_PWM && pwm->pwm_set_intensity)
                pwm->pwm_set_intensity(0, max_brightness);

        err = lm3530_init_registers(drvdata);
        if (err) {
                dev_err(dev, "Setting %s Mode failed :%d\n", buf, err);
                return err;
        }

        return sizeof(drvdata->mode);
}
static DEVICE_ATTR_RW(mode);

static struct attribute *lm3530_attrs[] = {
        &dev_attr_mode.attr,
        NULL
};
ATTRIBUTE_GROUPS(lm3530);

static int lm3530_probe(struct i2c_client *client)
{
        struct lm3530_platform_data *pdata = dev_get_platdata(&client->dev);
        struct lm3530_data *drvdata;
        int err = 0;

        if (pdata == NULL) {
                dev_err(&client->dev, "platform data required\n");
                return -ENODEV;
        }

        /* BL mode */
        if (pdata->mode > LM3530_BL_MODE_PWM) {
                dev_err(&client->dev, "Illegal Mode request\n");
                return -EINVAL;
        }

        if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) {
                dev_err(&client->dev, "I2C_FUNC_I2C not supported\n");
                return -EIO;
        }

        drvdata = devm_kzalloc(&client->dev, sizeof(struct lm3530_data),
                                GFP_KERNEL);
        if (drvdata == NULL)
                return -ENOMEM;

        drvdata->mode = pdata->mode;
        drvdata->client = client;
        drvdata->pdata = pdata;
        drvdata->brightness = LED_OFF;
        drvdata->enable = false;
        drvdata->led_dev.name = LM3530_LED_DEV;
        drvdata->led_dev.brightness_set = lm3530_brightness_set;
        drvdata->led_dev.max_brightness = MAX_BRIGHTNESS;
        drvdata->led_dev.groups = lm3530_groups;

        i2c_set_clientdata(client, drvdata);

        drvdata->regulator = devm_regulator_get(&client->dev, "vin");
        if (IS_ERR(drvdata->regulator)) {
                dev_err(&client->dev, "regulator get failed\n");
                err = PTR_ERR(drvdata->regulator);
                drvdata->regulator = NULL;
                return err;
        }

        if (drvdata->pdata->brt_val) {
                err = lm3530_init_registers(drvdata);
                if (err < 0) {
                        dev_err(&client->dev,
                                "Register Init failed: %d\n", err);
                        return err;
                }
        }
        err = led_classdev_register(&client->dev, &drvdata->led_dev);
        if (err < 0) {
                dev_err(&client->dev, "Register led class failed: %d\n", err);
                return err;
        }

        return 0;
}

static void lm3530_remove(struct i2c_client *client)
{
        struct lm3530_data *drvdata = i2c_get_clientdata(client);

        lm3530_led_disable(drvdata);
        led_classdev_unregister(&drvdata->led_dev);
}

static const struct i2c_device_id lm3530_id[] = {
        { LM3530_NAME },
        {}
};
MODULE_DEVICE_TABLE(i2c, lm3530_id);

static struct i2c_driver lm3530_i2c_driver = {
        .probe = lm3530_probe,
        .remove = lm3530_remove,
        .id_table = lm3530_id,
        .driver = {
                .name = LM3530_NAME,
        },
};

module_i2c_driver(lm3530_i2c_driver);

MODULE_DESCRIPTION("Back Light driver for LM3530");
MODULE_LICENSE("GPL v2");
MODULE_AUTHOR("Shreshtha Kumar SAHU <shreshthakumar.sahu@stericsson.com>");