/*
 * LED Flash class interface
 *
 * Copyright (C) 2015 Samsung Electronics Co., Ltd.
 * Author: Jacek Anaszewski <j.anaszewski@samsung.com>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 */

#include <linux/device.h>
#include <linux/init.h>
#include <linux/led-class-flash.h>
#include <linux/leds.h>
#include <linux/module.h>
#include <linux/slab.h>
#include "leds.h"

#define has_flash_op(fled_cdev, op)                             \
        (fled_cdev && fled_cdev->ops->op)

#define call_flash_op(fled_cdev, op, args...)           \
        ((has_flash_op(fled_cdev, op)) ?                        \
                        (fled_cdev->ops->op(fled_cdev, args)) : \
                        -EINVAL)

static const char * const led_flash_fault_names[] = {
        "led-over-voltage",
        "flash-timeout-exceeded",
        "controller-over-temperature",
        "controller-short-circuit",
        "led-power-supply-over-current",
        "indicator-led-fault",
        "led-under-voltage",
        "controller-under-voltage",
        "led-over-temperature",
};

static ssize_t flash_brightness_store(struct device *dev,
                struct device_attribute *attr, const char *buf, size_t size)
{
        struct led_classdev *led_cdev = dev_get_drvdata(dev);
        struct led_classdev_flash *fled_cdev = lcdev_to_flcdev(led_cdev);
        unsigned long state;
        ssize_t ret;

        mutex_lock(&led_cdev->led_access);

        if (led_sysfs_is_disabled(led_cdev)) {
                ret = -EBUSY;
                goto unlock;
        }

        ret = kstrtoul(buf, 10, &state);
        if (ret)
                goto unlock;

        ret = led_set_flash_brightness(fled_cdev, state);
        if (ret < 0)
                goto unlock;

        ret = size;
unlock:
        mutex_unlock(&led_cdev->led_access);
        return ret;
}

static ssize_t flash_brightness_show(struct device *dev,
                struct device_attribute *attr, char *buf)
{
        struct led_classdev *led_cdev = dev_get_drvdata(dev);
        struct led_classdev_flash *fled_cdev = lcdev_to_flcdev(led_cdev);

        /* no lock needed for this */
        led_update_flash_brightness(fled_cdev);

        return sprintf(buf, "%u\n", fled_cdev->brightness.val);
}
static DEVICE_ATTR_RW(flash_brightness);

static ssize_t max_flash_brightness_show(struct device *dev,
                struct device_attribute *attr, char *buf)
{
        struct led_classdev *led_cdev = dev_get_drvdata(dev);
        struct led_classdev_flash *fled_cdev = lcdev_to_flcdev(led_cdev);

        return sprintf(buf, "%u\n", fled_cdev->brightness.max);
}
static DEVICE_ATTR_RO(max_flash_brightness);

static ssize_t flash_strobe_store(struct device *dev,
                struct device_attribute *attr, const char *buf, size_t size)
{
        struct led_classdev *led_cdev = dev_get_drvdata(dev);
        struct led_classdev_flash *fled_cdev = lcdev_to_flcdev(led_cdev);
        unsigned long state;
        ssize_t ret = -EINVAL;

        mutex_lock(&led_cdev->led_access);

        if (led_sysfs_is_disabled(led_cdev)) {
                ret = -EBUSY;
                goto unlock;
        }

        ret = kstrtoul(buf, 10, &state);
        if (ret)
                goto unlock;

        if (state > 1) {
                ret = -EINVAL;
                goto unlock;
        }

        ret = led_set_flash_strobe(fled_cdev, state);
        if (ret < 0)
                goto unlock;
        ret = size;
unlock:
        mutex_unlock(&led_cdev->led_access);
        return ret;
}

static ssize_t flash_strobe_show(struct device *dev,
                struct device_attribute *attr, char *buf)
{
        struct led_classdev *led_cdev = dev_get_drvdata(dev);
        struct led_classdev_flash *fled_cdev = lcdev_to_flcdev(led_cdev);
        bool state;
        int ret;

        /* no lock needed for this */
        ret = led_get_flash_strobe(fled_cdev, &state);
        if (ret < 0)
                return ret;

        return sprintf(buf, "%u\n", state);
}
static DEVICE_ATTR_RW(flash_strobe);

static ssize_t flash_timeout_store(struct device *dev,
                struct device_attribute *attr, const char *buf, size_t size)
{
        struct led_classdev *led_cdev = dev_get_drvdata(dev);
        struct led_classdev_flash *fled_cdev = lcdev_to_flcdev(led_cdev);
        unsigned long flash_timeout;
        ssize_t ret;

        mutex_lock(&led_cdev->led_access);

        if (led_sysfs_is_disabled(led_cdev)) {
                ret = -EBUSY;
                goto unlock;
        }

        ret = kstrtoul(buf, 10, &flash_timeout);
        if (ret)
                goto unlock;

        ret = led_set_flash_timeout(fled_cdev, flash_timeout);
        if (ret < 0)
                goto unlock;

        ret = size;
unlock:
        mutex_unlock(&led_cdev->led_access);
        return ret;
}

static ssize_t flash_timeout_show(struct device *dev,
                struct device_attribute *attr, char *buf)
{
        struct led_classdev *led_cdev = dev_get_drvdata(dev);
        struct led_classdev_flash *fled_cdev = lcdev_to_flcdev(led_cdev);

        return sprintf(buf, "%u\n", fled_cdev->timeout.val);
}
static DEVICE_ATTR_RW(flash_timeout);

static ssize_t max_flash_timeout_show(struct device *dev,
                struct device_attribute *attr, char *buf)
{
        struct led_classdev *led_cdev = dev_get_drvdata(dev);
        struct led_classdev_flash *fled_cdev = lcdev_to_flcdev(led_cdev);

        return sprintf(buf, "%u\n", fled_cdev->timeout.max);
}
static DEVICE_ATTR_RO(max_flash_timeout);

static ssize_t flash_fault_show(struct device *dev,
                struct device_attribute *attr, char *buf)
{
        struct led_classdev *led_cdev = dev_get_drvdata(dev);
        struct led_classdev_flash *fled_cdev = lcdev_to_flcdev(led_cdev);
        u32 fault, mask = 0x1;
        char *pbuf = buf;
        int i, ret, buf_len;

        ret = led_get_flash_fault(fled_cdev, &fault);
        if (ret < 0)
                return -EINVAL;

        *buf = '\0';

        for (i = 0; i < LED_NUM_FLASH_FAULTS; ++i) {
                if (fault & mask) {
                        buf_len = sprintf(pbuf, "%s ",
                                          led_flash_fault_names[i]);
                        pbuf += buf_len;
                }
                mask <<= 1;
        }

        return sprintf(buf, "%s\n", buf);
}
static DEVICE_ATTR_RO(flash_fault);

static struct attribute *led_flash_strobe_attrs[] = {
        &dev_attr_flash_strobe.attr,
        NULL,
};

static struct attribute *led_flash_timeout_attrs[] = {
        &dev_attr_flash_timeout.attr,
        &dev_attr_max_flash_timeout.attr,
        NULL,
};

static struct attribute *led_flash_brightness_attrs[] = {
        &dev_attr_flash_brightness.attr,
        &dev_attr_max_flash_brightness.attr,
        NULL,
};

static struct attribute *led_flash_fault_attrs[] = {
        &dev_attr_flash_fault.attr,
        NULL,
};

static const struct attribute_group led_flash_strobe_group = {
        .attrs = led_flash_strobe_attrs,
};

static const struct attribute_group led_flash_timeout_group = {
        .attrs = led_flash_timeout_attrs,
};

static const struct attribute_group led_flash_brightness_group = {
        .attrs = led_flash_brightness_attrs,
};

static const struct attribute_group led_flash_fault_group = {
        .attrs = led_flash_fault_attrs,
};

static void led_flash_resume(struct led_classdev *led_cdev)
{
        struct led_classdev_flash *fled_cdev = lcdev_to_flcdev(led_cdev);

        call_flash_op(fled_cdev, flash_brightness_set,
                                        fled_cdev->brightness.val);
        call_flash_op(fled_cdev, timeout_set, fled_cdev->timeout.val);
}

static void led_flash_init_sysfs_groups(struct led_classdev_flash *fled_cdev)
{
        struct led_classdev *led_cdev = &fled_cdev->led_cdev;
        const struct led_flash_ops *ops = fled_cdev->ops;
        const struct attribute_group **flash_groups = fled_cdev->sysfs_groups;

        int num_sysfs_groups = 0;

        flash_groups[num_sysfs_groups++] = &led_flash_strobe_group;

        if (ops->flash_brightness_set)
                flash_groups[num_sysfs_groups++] = &led_flash_brightness_group;

        if (ops->timeout_set)
                flash_groups[num_sysfs_groups++] = &led_flash_timeout_group;

        if (ops->fault_get)
                flash_groups[num_sysfs_groups++] = &led_flash_fault_group;

        led_cdev->groups = flash_groups;
}

int led_classdev_flash_register(struct device *parent,
                                struct led_classdev_flash *fled_cdev)
{
        struct led_classdev *led_cdev;
        const struct led_flash_ops *ops;
        int ret;

        if (!fled_cdev)
                return -EINVAL;

        led_cdev = &fled_cdev->led_cdev;

        if (led_cdev->flags & LED_DEV_CAP_FLASH) {
                if (!led_cdev->brightness_set_blocking)
                        return -EINVAL;

                ops = fled_cdev->ops;
                if (!ops || !ops->strobe_set)
                        return -EINVAL;

                led_cdev->flash_resume = led_flash_resume;

                /* Select the sysfs attributes to be created for the device */
                led_flash_init_sysfs_groups(fled_cdev);
        }

        /* Register led class device */
        ret = led_classdev_register(parent, led_cdev);
        if (ret < 0)
                return ret;

        return 0;
}
EXPORT_SYMBOL_GPL(led_classdev_flash_register);

void led_classdev_flash_unregister(struct led_classdev_flash *fled_cdev)
{
        if (!fled_cdev)
                return;

        led_classdev_unregister(&fled_cdev->led_cdev);
}
EXPORT_SYMBOL_GPL(led_classdev_flash_unregister);

static void led_clamp_align(struct led_flash_setting *s)
{
        u32 v, offset;

        v = s->val + s->step / 2;
        v = clamp(v, s->min, s->max);
        offset = v - s->min;
        offset = s->step * (offset / s->step);
        s->val = s->min + offset;
}

int led_set_flash_timeout(struct led_classdev_flash *fled_cdev, u32 timeout)
{
        struct led_classdev *led_cdev = &fled_cdev->led_cdev;
        struct led_flash_setting *s = &fled_cdev->timeout;

        s->val = timeout;
        led_clamp_align(s);

        if (!(led_cdev->flags & LED_SUSPENDED))
                return call_flash_op(fled_cdev, timeout_set, s->val);

        return 0;
}
EXPORT_SYMBOL_GPL(led_set_flash_timeout);

int led_get_flash_fault(struct led_classdev_flash *fled_cdev, u32 *fault)
{
        return call_flash_op(fled_cdev, fault_get, fault);
}
EXPORT_SYMBOL_GPL(led_get_flash_fault);

int led_set_flash_brightness(struct led_classdev_flash *fled_cdev,
                                u32 brightness)
{
        struct led_classdev *led_cdev = &fled_cdev->led_cdev;
        struct led_flash_setting *s = &fled_cdev->brightness;

        s->val = brightness;
        led_clamp_align(s);

        if (!(led_cdev->flags & LED_SUSPENDED))
                return call_flash_op(fled_cdev, flash_brightness_set, s->val);

        return 0;
}
EXPORT_SYMBOL_GPL(led_set_flash_brightness);

int led_update_flash_brightness(struct led_classdev_flash *fled_cdev)
{
        struct led_flash_setting *s = &fled_cdev->brightness;
        u32 brightness;

        if (has_flash_op(fled_cdev, flash_brightness_get)) {
                int ret = call_flash_op(fled_cdev, flash_brightness_get,
                                                &brightness);
                if (ret < 0)
                        return ret;

                s->val = brightness;
        }

        return 0;
}
EXPORT_SYMBOL_GPL(led_update_flash_brightness);

MODULE_AUTHOR("Jacek Anaszewski <j.anaszewski@samsung.com>");
MODULE_DESCRIPTION("LED Flash class interface");
MODULE_LICENSE("GPL v2");