// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * leds-lm3533.c -- LM3533 LED driver
 *
 * Copyright (C) 2011-2012 Texas Instruments
 *
 * Author: Johan Hovold <jhovold@gmail.com>
 */

#include <linux/module.h>
#include <linux/leds.h>
#include <linux/mfd/core.h>
#include <linux/mutex.h>
#include <linux/platform_device.h>
#include <linux/slab.h>

#include <linux/mfd/lm3533.h>


#define LM3533_LVCTRLBANK_MIN           2
#define LM3533_LVCTRLBANK_MAX           5
#define LM3533_LVCTRLBANK_COUNT         4
#define LM3533_RISEFALLTIME_MAX         7
#define LM3533_ALS_CHANNEL_LV_MIN       1
#define LM3533_ALS_CHANNEL_LV_MAX       2

#define LM3533_REG_CTRLBANK_BCONF_BASE          0x1b
#define LM3533_REG_PATTERN_ENABLE               0x28
#define LM3533_REG_PATTERN_LOW_TIME_BASE        0x71
#define LM3533_REG_PATTERN_HIGH_TIME_BASE       0x72
#define LM3533_REG_PATTERN_RISETIME_BASE        0x74
#define LM3533_REG_PATTERN_FALLTIME_BASE        0x75

#define LM3533_REG_PATTERN_STEP                 0x10

#define LM3533_REG_CTRLBANK_BCONF_MAPPING_MASK          0x04
#define LM3533_REG_CTRLBANK_BCONF_ALS_EN_MASK           0x02
#define LM3533_REG_CTRLBANK_BCONF_ALS_CHANNEL_MASK      0x01

#define LM3533_LED_FLAG_PATTERN_ENABLE          1


struct lm3533_led {
        struct lm3533 *lm3533;
        struct lm3533_ctrlbank cb;
        struct led_classdev cdev;
        int id;

        struct mutex mutex;
        unsigned long flags;
};


static inline struct lm3533_led *to_lm3533_led(struct led_classdev *cdev)
{
        return container_of(cdev, struct lm3533_led, cdev);
}

static inline int lm3533_led_get_ctrlbank_id(struct lm3533_led *led)
{
        return led->id + 2;
}

static inline u8 lm3533_led_get_lv_reg(struct lm3533_led *led, u8 base)
{
        return base + led->id;
}

static inline u8 lm3533_led_get_pattern(struct lm3533_led *led)
{
        return led->id;
}

static inline u8 lm3533_led_get_pattern_reg(struct lm3533_led *led,
                                                                u8 base)
{
        return base + lm3533_led_get_pattern(led) * LM3533_REG_PATTERN_STEP;
}

static int lm3533_led_pattern_enable(struct lm3533_led *led, int enable)
{
        u8 mask;
        u8 val;
        int pattern;
        int state;
        int ret = 0;

        dev_dbg(led->cdev.dev, "%s - %d\n", __func__, enable);

        mutex_lock(&led->mutex);

        state = test_bit(LM3533_LED_FLAG_PATTERN_ENABLE, &led->flags);
        if ((enable && state) || (!enable && !state))
                goto out;

        pattern = lm3533_led_get_pattern(led);
        mask = 1 << (2 * pattern);

        if (enable)
                val = mask;
        else
                val = 0;

        ret = lm3533_update(led->lm3533, LM3533_REG_PATTERN_ENABLE, val, mask);
        if (ret) {
                dev_err(led->cdev.dev, "failed to enable pattern %d (%d)\n",
                                                        pattern, enable);
                goto out;
        }

        __change_bit(LM3533_LED_FLAG_PATTERN_ENABLE, &led->flags);
out:
        mutex_unlock(&led->mutex);

        return ret;
}

static int lm3533_led_set(struct led_classdev *cdev,
                                                enum led_brightness value)
{
        struct lm3533_led *led = to_lm3533_led(cdev);

        dev_dbg(led->cdev.dev, "%s - %d\n", __func__, value);

        if (value == 0)
                lm3533_led_pattern_enable(led, 0);      /* disable blink */

        return lm3533_ctrlbank_set_brightness(&led->cb, value);
}

static enum led_brightness lm3533_led_get(struct led_classdev *cdev)
{
        struct lm3533_led *led = to_lm3533_led(cdev);
        u8 val;
        int ret;

        ret = lm3533_ctrlbank_get_brightness(&led->cb, &val);
        if (ret)
                return ret;

        dev_dbg(led->cdev.dev, "%s - %u\n", __func__, val);

        return val;
}

/* Pattern generator defines (delays in us). */
#define LM3533_LED_DELAY1_VMIN  0x00
#define LM3533_LED_DELAY2_VMIN  0x3d
#define LM3533_LED_DELAY3_VMIN  0x80

#define LM3533_LED_DELAY1_VMAX  (LM3533_LED_DELAY2_VMIN - 1)
#define LM3533_LED_DELAY2_VMAX  (LM3533_LED_DELAY3_VMIN - 1)
#define LM3533_LED_DELAY3_VMAX  0xff

#define LM3533_LED_DELAY1_TMIN  16384U
#define LM3533_LED_DELAY2_TMIN  1130496U
#define LM3533_LED_DELAY3_TMIN  10305536U

#define LM3533_LED_DELAY1_TMAX  999424U
#define LM3533_LED_DELAY2_TMAX  9781248U
#define LM3533_LED_DELAY3_TMAX  76890112U

/* t_step = (t_max - t_min) / (v_max - v_min) */
#define LM3533_LED_DELAY1_TSTEP 16384
#define LM3533_LED_DELAY2_TSTEP 131072
#define LM3533_LED_DELAY3_TSTEP 524288

/* Delay limits for hardware accelerated blinking (in ms). */
#define LM3533_LED_DELAY_ON_MAX \
        ((LM3533_LED_DELAY2_TMAX + LM3533_LED_DELAY2_TSTEP / 2) / 1000)
#define LM3533_LED_DELAY_OFF_MAX \
        ((LM3533_LED_DELAY3_TMAX + LM3533_LED_DELAY3_TSTEP / 2) / 1000)

/*
 * Returns linear map of *t from [t_min,t_max] to [v_min,v_max] with a step
 * size of t_step, where
 *
 *      t_step = (t_max - t_min) / (v_max - v_min)
 *
 * and updates *t to reflect the mapped value.
 */
static u8 time_to_val(unsigned *t, unsigned t_min, unsigned t_step,
                                                        u8 v_min, u8 v_max)
{
        unsigned val;

        val = (*t + t_step / 2 - t_min) / t_step + v_min;

        *t = t_step * (val - v_min) + t_min;

        return (u8)val;
}

/*
 * Returns time code corresponding to *delay (in ms) and updates *delay to
 * reflect actual hardware delay.
 *
 * Hardware supports 256 discrete delay times, divided into three groups with
 * the following ranges and step-sizes:
 *
 *      [   16,   999]  [0x00, 0x3e]    step  16 ms
 *      [ 1130,  9781]  [0x3d, 0x7f]    step 131 ms
 *      [10306, 76890]  [0x80, 0xff]    step 524 ms
 *
 * Note that delay group 3 is only available for delay_off.
 */
static u8 lm3533_led_get_hw_delay(unsigned *delay)
{
        unsigned t;
        u8 val;

        t = *delay * 1000;

        if (t >= (LM3533_LED_DELAY2_TMAX + LM3533_LED_DELAY3_TMIN) / 2) {
                t = clamp(t, LM3533_LED_DELAY3_TMIN, LM3533_LED_DELAY3_TMAX);
                val = time_to_val(&t,   LM3533_LED_DELAY3_TMIN,
                                        LM3533_LED_DELAY3_TSTEP,
                                        LM3533_LED_DELAY3_VMIN,
                                        LM3533_LED_DELAY3_VMAX);
        } else if (t >= (LM3533_LED_DELAY1_TMAX + LM3533_LED_DELAY2_TMIN) / 2) {
                t = clamp(t, LM3533_LED_DELAY2_TMIN, LM3533_LED_DELAY2_TMAX);
                val = time_to_val(&t,   LM3533_LED_DELAY2_TMIN,
                                        LM3533_LED_DELAY2_TSTEP,
                                        LM3533_LED_DELAY2_VMIN,
                                        LM3533_LED_DELAY2_VMAX);
        } else {
                t = clamp(t, LM3533_LED_DELAY1_TMIN, LM3533_LED_DELAY1_TMAX);
                val = time_to_val(&t,   LM3533_LED_DELAY1_TMIN,
                                        LM3533_LED_DELAY1_TSTEP,
                                        LM3533_LED_DELAY1_VMIN,
                                        LM3533_LED_DELAY1_VMAX);
        }

        *delay = (t + 500) / 1000;

        return val;
}

/*
 * Set delay register base to *delay (in ms) and update *delay to reflect
 * actual hardware delay used.
 */
static u8 lm3533_led_delay_set(struct lm3533_led *led, u8 base,
                                                        unsigned long *delay)
{
        unsigned t;
        u8 val;
        u8 reg;
        int ret;

        t = (unsigned)*delay;

        /* Delay group 3 is only available for low time (delay off). */
        if (base != LM3533_REG_PATTERN_LOW_TIME_BASE)
                t = min(t, LM3533_LED_DELAY2_TMAX / 1000);

        val = lm3533_led_get_hw_delay(&t);

        dev_dbg(led->cdev.dev, "%s - %lu: %u (0x%02x)\n", __func__,
                                                        *delay, t, val);
        reg = lm3533_led_get_pattern_reg(led, base);
        ret = lm3533_write(led->lm3533, reg, val);
        if (ret)
                dev_err(led->cdev.dev, "failed to set delay (%02x)\n", reg);

        *delay = t;

        return ret;
}

static int lm3533_led_delay_on_set(struct lm3533_led *led, unsigned long *t)
{
        return lm3533_led_delay_set(led, LM3533_REG_PATTERN_HIGH_TIME_BASE, t);
}

static int lm3533_led_delay_off_set(struct lm3533_led *led, unsigned long *t)
{
        return lm3533_led_delay_set(led, LM3533_REG_PATTERN_LOW_TIME_BASE, t);
}

static int lm3533_led_blink_set(struct led_classdev *cdev,
                                unsigned long *delay_on,
                                unsigned long *delay_off)
{
        struct lm3533_led *led = to_lm3533_led(cdev);
        int ret;

        dev_dbg(led->cdev.dev, "%s - on = %lu, off = %lu\n", __func__,
                                                        *delay_on, *delay_off);

        if (*delay_on > LM3533_LED_DELAY_ON_MAX ||
                                        *delay_off > LM3533_LED_DELAY_OFF_MAX)
                return -EINVAL;

        if (*delay_on == 0 && *delay_off == 0) {
                *delay_on = 500;
                *delay_off = 500;
        }

        ret = lm3533_led_delay_on_set(led, delay_on);
        if (ret)
                return ret;

        ret = lm3533_led_delay_off_set(led, delay_off);
        if (ret)
                return ret;

        return lm3533_led_pattern_enable(led, 1);
}

static ssize_t show_id(struct device *dev,
                                struct device_attribute *attr, char *buf)
{
        struct led_classdev *led_cdev = dev_get_drvdata(dev);
        struct lm3533_led *led = to_lm3533_led(led_cdev);

        return sysfs_emit(buf, "%d\n", led->id);
}

/*
 * Pattern generator rise/fall times:
 *
 *   0 - 2048 us (default)
 *   1 - 262 ms
 *   2 - 524 ms
 *   3 - 1.049 s
 *   4 - 2.097 s
 *   5 - 4.194 s
 *   6 - 8.389 s
 *   7 - 16.78 s
 */
static ssize_t show_risefalltime(struct device *dev,
                                        struct device_attribute *attr,
                                        char *buf, u8 base)
{
        struct led_classdev *led_cdev = dev_get_drvdata(dev);
        struct lm3533_led *led = to_lm3533_led(led_cdev);
        ssize_t ret;
        u8 reg;
        u8 val;

        reg = lm3533_led_get_pattern_reg(led, base);
        ret = lm3533_read(led->lm3533, reg, &val);
        if (ret)
                return ret;

        return sysfs_emit(buf, "%x\n", val);
}

static ssize_t show_risetime(struct device *dev,
                                struct device_attribute *attr, char *buf)
{
        return show_risefalltime(dev, attr, buf,
                                        LM3533_REG_PATTERN_RISETIME_BASE);
}

static ssize_t show_falltime(struct device *dev,
                                struct device_attribute *attr, char *buf)
{
        return show_risefalltime(dev, attr, buf,
                                        LM3533_REG_PATTERN_FALLTIME_BASE);
}

static ssize_t store_risefalltime(struct device *dev,
                                        struct device_attribute *attr,
                                        const char *buf, size_t len, u8 base)
{
        struct led_classdev *led_cdev = dev_get_drvdata(dev);
        struct lm3533_led *led = to_lm3533_led(led_cdev);
        u8 val;
        u8 reg;
        int ret;

        if (kstrtou8(buf, 0, &val) || val > LM3533_RISEFALLTIME_MAX)
                return -EINVAL;

        reg = lm3533_led_get_pattern_reg(led, base);
        ret = lm3533_write(led->lm3533, reg, val);
        if (ret)
                return ret;

        return len;
}

static ssize_t store_risetime(struct device *dev,
                                        struct device_attribute *attr,
                                        const char *buf, size_t len)
{
        return store_risefalltime(dev, attr, buf, len,
                                        LM3533_REG_PATTERN_RISETIME_BASE);
}

static ssize_t store_falltime(struct device *dev,
                                        struct device_attribute *attr,
                                        const char *buf, size_t len)
{
        return store_risefalltime(dev, attr, buf, len,
                                        LM3533_REG_PATTERN_FALLTIME_BASE);
}

static ssize_t show_als_channel(struct device *dev,
                                struct device_attribute *attr, char *buf)
{
        struct led_classdev *led_cdev = dev_get_drvdata(dev);
        struct lm3533_led *led = to_lm3533_led(led_cdev);
        unsigned channel;
        u8 reg;
        u8 val;
        int ret;

        reg = lm3533_led_get_lv_reg(led, LM3533_REG_CTRLBANK_BCONF_BASE);
        ret = lm3533_read(led->lm3533, reg, &val);
        if (ret)
                return ret;

        channel = (val & LM3533_REG_CTRLBANK_BCONF_ALS_CHANNEL_MASK) + 1;

        return sysfs_emit(buf, "%u\n", channel);
}

static ssize_t store_als_channel(struct device *dev,
                                        struct device_attribute *attr,
                                        const char *buf, size_t len)
{
        struct led_classdev *led_cdev = dev_get_drvdata(dev);
        struct lm3533_led *led = to_lm3533_led(led_cdev);
        unsigned channel;
        u8 reg;
        u8 val;
        u8 mask;
        int ret;

        if (kstrtouint(buf, 0, &channel))
                return -EINVAL;

        if (channel < LM3533_ALS_CHANNEL_LV_MIN ||
                                        channel > LM3533_ALS_CHANNEL_LV_MAX)
                return -EINVAL;

        reg = lm3533_led_get_lv_reg(led, LM3533_REG_CTRLBANK_BCONF_BASE);
        mask = LM3533_REG_CTRLBANK_BCONF_ALS_CHANNEL_MASK;
        val = channel - 1;

        ret = lm3533_update(led->lm3533, reg, val, mask);
        if (ret)
                return ret;

        return len;
}

static ssize_t show_als_en(struct device *dev,
                                struct device_attribute *attr, char *buf)
{
        struct led_classdev *led_cdev = dev_get_drvdata(dev);
        struct lm3533_led *led = to_lm3533_led(led_cdev);
        bool enable;
        u8 reg;
        u8 val;
        int ret;

        reg = lm3533_led_get_lv_reg(led, LM3533_REG_CTRLBANK_BCONF_BASE);
        ret = lm3533_read(led->lm3533, reg, &val);
        if (ret)
                return ret;

        enable = val & LM3533_REG_CTRLBANK_BCONF_ALS_EN_MASK;

        return sysfs_emit(buf, "%d\n", enable);
}

static ssize_t store_als_en(struct device *dev,
                                        struct device_attribute *attr,
                                        const char *buf, size_t len)
{
        struct led_classdev *led_cdev = dev_get_drvdata(dev);
        struct lm3533_led *led = to_lm3533_led(led_cdev);
        unsigned enable;
        u8 reg;
        u8 mask;
        u8 val;
        int ret;

        if (kstrtouint(buf, 0, &enable))
                return -EINVAL;

        reg = lm3533_led_get_lv_reg(led, LM3533_REG_CTRLBANK_BCONF_BASE);
        mask = LM3533_REG_CTRLBANK_BCONF_ALS_EN_MASK;

        if (enable)
                val = mask;
        else
                val = 0;

        ret = lm3533_update(led->lm3533, reg, val, mask);
        if (ret)
                return ret;

        return len;
}

static ssize_t show_linear(struct device *dev,
                                struct device_attribute *attr, char *buf)
{
        struct led_classdev *led_cdev = dev_get_drvdata(dev);
        struct lm3533_led *led = to_lm3533_led(led_cdev);
        u8 reg;
        u8 val;
        int linear;
        int ret;

        reg = lm3533_led_get_lv_reg(led, LM3533_REG_CTRLBANK_BCONF_BASE);
        ret = lm3533_read(led->lm3533, reg, &val);
        if (ret)
                return ret;

        if (val & LM3533_REG_CTRLBANK_BCONF_MAPPING_MASK)
                linear = 1;
        else
                linear = 0;

        return sysfs_emit(buf, "%x\n", linear);
}

static ssize_t store_linear(struct device *dev,
                                        struct device_attribute *attr,
                                        const char *buf, size_t len)
{
        struct led_classdev *led_cdev = dev_get_drvdata(dev);
        struct lm3533_led *led = to_lm3533_led(led_cdev);
        unsigned long linear;
        u8 reg;
        u8 mask;
        u8 val;
        int ret;

        if (kstrtoul(buf, 0, &linear))
                return -EINVAL;

        reg = lm3533_led_get_lv_reg(led, LM3533_REG_CTRLBANK_BCONF_BASE);
        mask = LM3533_REG_CTRLBANK_BCONF_MAPPING_MASK;

        if (linear)
                val = mask;
        else
                val = 0;

        ret = lm3533_update(led->lm3533, reg, val, mask);
        if (ret)
                return ret;

        return len;
}

static ssize_t show_pwm(struct device *dev,
                                        struct device_attribute *attr,
                                        char *buf)
{
        struct led_classdev *led_cdev = dev_get_drvdata(dev);
        struct lm3533_led *led = to_lm3533_led(led_cdev);
        u8 val;
        int ret;

        ret = lm3533_ctrlbank_get_pwm(&led->cb, &val);
        if (ret)
                return ret;

        return sysfs_emit(buf, "%u\n", val);
}

static ssize_t store_pwm(struct device *dev,
                                        struct device_attribute *attr,
                                        const char *buf, size_t len)
{
        struct led_classdev *led_cdev = dev_get_drvdata(dev);
        struct lm3533_led *led = to_lm3533_led(led_cdev);
        u8 val;
        int ret;

        if (kstrtou8(buf, 0, &val))
                return -EINVAL;

        ret = lm3533_ctrlbank_set_pwm(&led->cb, val);
        if (ret)
                return ret;

        return len;
}

static LM3533_ATTR_RW(als_channel);
static LM3533_ATTR_RW(als_en);
static LM3533_ATTR_RW(falltime);
static LM3533_ATTR_RO(id);
static LM3533_ATTR_RW(linear);
static LM3533_ATTR_RW(pwm);
static LM3533_ATTR_RW(risetime);

static struct attribute *lm3533_led_attributes[] = {
        &dev_attr_als_channel.attr,
        &dev_attr_als_en.attr,
        &dev_attr_falltime.attr,
        &dev_attr_id.attr,
        &dev_attr_linear.attr,
        &dev_attr_pwm.attr,
        &dev_attr_risetime.attr,
        NULL,
};

static umode_t lm3533_led_attr_is_visible(struct kobject *kobj,
                                             struct attribute *attr, int n)
{
        struct device *dev = kobj_to_dev(kobj);
        struct led_classdev *led_cdev = dev_get_drvdata(dev);
        struct lm3533_led *led = to_lm3533_led(led_cdev);
        umode_t mode = attr->mode;

        if (attr == &dev_attr_als_channel.attr ||
                                        attr == &dev_attr_als_en.attr) {
                if (!led->lm3533->have_als)
                        mode = 0;
        }

        return mode;
};

static const struct attribute_group lm3533_led_attribute_group = {
        .is_visible     = lm3533_led_attr_is_visible,
        .attrs          = lm3533_led_attributes
};

static const struct attribute_group *lm3533_led_attribute_groups[] = {
        &lm3533_led_attribute_group,
        NULL
};

static int lm3533_led_setup(struct lm3533_led *led,
                                        struct lm3533_led_platform_data *pdata)
{
        int ret;

        ret = lm3533_ctrlbank_set_max_current(&led->cb, pdata->max_current);
        if (ret)
                return ret;

        return lm3533_ctrlbank_set_pwm(&led->cb, pdata->pwm);
}

static int lm3533_led_probe(struct platform_device *pdev)
{
        struct lm3533 *lm3533;
        struct lm3533_led_platform_data *pdata;
        struct lm3533_led *led;
        int ret;

        dev_dbg(&pdev->dev, "%s\n", __func__);

        lm3533 = dev_get_drvdata(pdev->dev.parent);
        if (!lm3533)
                return -EINVAL;

        pdata = dev_get_platdata(&pdev->dev);
        if (!pdata) {
                dev_err(&pdev->dev, "no platform data\n");
                return -EINVAL;
        }

        if (pdev->id < 0 || pdev->id >= LM3533_LVCTRLBANK_COUNT) {
                dev_err(&pdev->dev, "illegal LED id %d\n", pdev->id);
                return -EINVAL;
        }

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

        led->lm3533 = lm3533;
        led->cdev.name = pdata->name;
        led->cdev.default_trigger = pdata->default_trigger;
        led->cdev.brightness_set_blocking = lm3533_led_set;
        led->cdev.brightness_get = lm3533_led_get;
        led->cdev.blink_set = lm3533_led_blink_set;
        led->cdev.brightness = LED_OFF;
        led->cdev.groups = lm3533_led_attribute_groups;
        led->id = pdev->id;

        mutex_init(&led->mutex);

        /* The class framework makes a callback to get brightness during
         * registration so use parent device (for error reporting) until
         * registered.
         */
        led->cb.lm3533 = lm3533;
        led->cb.id = lm3533_led_get_ctrlbank_id(led);
        led->cb.dev = lm3533->dev;

        platform_set_drvdata(pdev, led);

        ret = led_classdev_register(pdev->dev.parent, &led->cdev);
        if (ret) {
                dev_err(&pdev->dev, "failed to register LED %d\n", pdev->id);
                return ret;
        }

        led->cb.dev = led->cdev.dev;

        ret = lm3533_led_setup(led, pdata);
        if (ret)
                goto err_deregister;

        ret = lm3533_ctrlbank_enable(&led->cb);
        if (ret)
                goto err_deregister;

        return 0;

err_deregister:
        led_classdev_unregister(&led->cdev);

        return ret;
}

static void lm3533_led_remove(struct platform_device *pdev)
{
        struct lm3533_led *led = platform_get_drvdata(pdev);

        dev_dbg(&pdev->dev, "%s\n", __func__);

        lm3533_ctrlbank_disable(&led->cb);
        led_classdev_unregister(&led->cdev);
}

static void lm3533_led_shutdown(struct platform_device *pdev)
{

        struct lm3533_led *led = platform_get_drvdata(pdev);

        dev_dbg(&pdev->dev, "%s\n", __func__);

        lm3533_ctrlbank_disable(&led->cb);
        lm3533_led_set(&led->cdev, LED_OFF);            /* disable blink */
}

static struct platform_driver lm3533_led_driver = {
        .driver = {
                .name = "lm3533-leds",
        },
        .probe          = lm3533_led_probe,
        .remove         = lm3533_led_remove,
        .shutdown       = lm3533_led_shutdown,
};
module_platform_driver(lm3533_led_driver);

MODULE_AUTHOR("Johan Hovold <jhovold@gmail.com>");
MODULE_DESCRIPTION("LM3533 LED driver");
MODULE_LICENSE("GPL");
MODULE_ALIAS("platform:lm3533-leds");