root/drivers/video/backlight/adp5520_bl.c
// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * Backlight driver for Analog Devices ADP5520/ADP5501 MFD PMICs
 *
 * Copyright 2009 Analog Devices Inc.
 */

#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/platform_device.h>
#include <linux/backlight.h>
#include <linux/mfd/adp5520.h>
#include <linux/slab.h>
#include <linux/module.h>

struct adp5520_bl {
        struct device *master;
        struct adp5520_backlight_platform_data *pdata;
        struct mutex lock;
        unsigned long cached_daylight_max;
        int id;
        int current_brightness;
};

static int adp5520_bl_set(struct backlight_device *bl, int brightness)
{
        struct adp5520_bl *data = bl_get_data(bl);
        struct device *master = data->master;
        int ret = 0;

        if (data->pdata->en_ambl_sens) {
                if ((brightness > 0) && (brightness < ADP5020_MAX_BRIGHTNESS)) {
                        /* Disable Ambient Light auto adjust */
                        ret |= adp5520_clr_bits(master, ADP5520_BL_CONTROL,
                                        ADP5520_BL_AUTO_ADJ);
                        ret |= adp5520_write(master, ADP5520_DAYLIGHT_MAX,
                                        brightness);
                } else {
                        /*
                         * MAX_BRIGHTNESS -> Enable Ambient Light auto adjust
                         * restore daylight l3 sysfs brightness
                         */
                        ret |= adp5520_write(master, ADP5520_DAYLIGHT_MAX,
                                         data->cached_daylight_max);
                        ret |= adp5520_set_bits(master, ADP5520_BL_CONTROL,
                                         ADP5520_BL_AUTO_ADJ);
                }
        } else {
                ret |= adp5520_write(master, ADP5520_DAYLIGHT_MAX, brightness);
        }

        if (data->current_brightness && brightness == 0)
                ret |= adp5520_set_bits(master,
                                ADP5520_MODE_STATUS, ADP5520_DIM_EN);
        else if (data->current_brightness == 0 && brightness)
                ret |= adp5520_clr_bits(master,
                                ADP5520_MODE_STATUS, ADP5520_DIM_EN);

        if (!ret)
                data->current_brightness = brightness;

        return ret;
}

static int adp5520_bl_update_status(struct backlight_device *bl)
{
        return adp5520_bl_set(bl, backlight_get_brightness(bl));
}

static int adp5520_bl_get_brightness(struct backlight_device *bl)
{
        struct adp5520_bl *data = bl_get_data(bl);
        int error;
        uint8_t reg_val;

        error = adp5520_read(data->master, ADP5520_BL_VALUE, &reg_val);

        return error ? data->current_brightness : reg_val;
}

static const struct backlight_ops adp5520_bl_ops = {
        .update_status  = adp5520_bl_update_status,
        .get_brightness = adp5520_bl_get_brightness,
};

static int adp5520_bl_setup(struct backlight_device *bl)
{
        struct adp5520_bl *data = bl_get_data(bl);
        struct device *master = data->master;
        struct adp5520_backlight_platform_data *pdata = data->pdata;
        int ret = 0;

        ret |= adp5520_write(master, ADP5520_DAYLIGHT_MAX,
                                pdata->l1_daylight_max);
        ret |= adp5520_write(master, ADP5520_DAYLIGHT_DIM,
                                pdata->l1_daylight_dim);

        if (pdata->en_ambl_sens) {
                data->cached_daylight_max = pdata->l1_daylight_max;
                ret |= adp5520_write(master, ADP5520_OFFICE_MAX,
                                pdata->l2_office_max);
                ret |= adp5520_write(master, ADP5520_OFFICE_DIM,
                                pdata->l2_office_dim);
                ret |= adp5520_write(master, ADP5520_DARK_MAX,
                                pdata->l3_dark_max);
                ret |= adp5520_write(master, ADP5520_DARK_DIM,
                                pdata->l3_dark_dim);
                ret |= adp5520_write(master, ADP5520_L2_TRIP,
                                pdata->l2_trip);
                ret |= adp5520_write(master, ADP5520_L2_HYS,
                                pdata->l2_hyst);
                ret |= adp5520_write(master, ADP5520_L3_TRIP,
                                 pdata->l3_trip);
                ret |= adp5520_write(master, ADP5520_L3_HYS,
                                pdata->l3_hyst);
                ret |= adp5520_write(master, ADP5520_ALS_CMPR_CFG,
                                ALS_CMPR_CFG_VAL(pdata->abml_filt,
                                ADP5520_L3_EN));
        }

        ret |= adp5520_write(master, ADP5520_BL_CONTROL,
                        BL_CTRL_VAL(pdata->fade_led_law,
                                        pdata->en_ambl_sens));

        ret |= adp5520_write(master, ADP5520_BL_FADE, FADE_VAL(pdata->fade_in,
                        pdata->fade_out));

        ret |= adp5520_set_bits(master, ADP5520_MODE_STATUS,
                        ADP5520_BL_EN | ADP5520_DIM_EN);

        return ret;
}

static ssize_t adp5520_show(struct device *dev, char *buf, int reg)
{
        struct adp5520_bl *data = dev_get_drvdata(dev);
        int ret;
        uint8_t reg_val;

        mutex_lock(&data->lock);
        ret = adp5520_read(data->master, reg, &reg_val);
        mutex_unlock(&data->lock);

        if (ret < 0)
                return ret;

        return sprintf(buf, "%u\n", reg_val);
}

static ssize_t adp5520_store(struct device *dev, const char *buf,
                         size_t count, int reg)
{
        struct adp5520_bl *data = dev_get_drvdata(dev);
        unsigned long val;
        int ret;

        ret = kstrtoul(buf, 10, &val);
        if (ret)
                return ret;

        mutex_lock(&data->lock);
        adp5520_write(data->master, reg, val);
        mutex_unlock(&data->lock);

        return count;
}

static ssize_t adp5520_bl_dark_max_show(struct device *dev,
                        struct device_attribute *attr, char *buf)
{
        return adp5520_show(dev, buf, ADP5520_DARK_MAX);
}

static ssize_t adp5520_bl_dark_max_store(struct device *dev,
                        struct device_attribute *attr,
                        const char *buf, size_t count)
{
        return adp5520_store(dev, buf, count, ADP5520_DARK_MAX);
}
static DEVICE_ATTR(dark_max, 0664, adp5520_bl_dark_max_show,
                        adp5520_bl_dark_max_store);

static ssize_t adp5520_bl_office_max_show(struct device *dev,
                        struct device_attribute *attr, char *buf)
{
        return adp5520_show(dev, buf, ADP5520_OFFICE_MAX);
}

static ssize_t adp5520_bl_office_max_store(struct device *dev,
                        struct device_attribute *attr,
                        const char *buf, size_t count)
{
        return adp5520_store(dev, buf, count, ADP5520_OFFICE_MAX);
}
static DEVICE_ATTR(office_max, 0664, adp5520_bl_office_max_show,
                        adp5520_bl_office_max_store);

static ssize_t adp5520_bl_daylight_max_show(struct device *dev,
                        struct device_attribute *attr, char *buf)
{
        return adp5520_show(dev, buf, ADP5520_DAYLIGHT_MAX);
}

static ssize_t adp5520_bl_daylight_max_store(struct device *dev,
                        struct device_attribute *attr,
                        const char *buf, size_t count)
{
        struct adp5520_bl *data = dev_get_drvdata(dev);
        int ret;

        ret = kstrtoul(buf, 10, &data->cached_daylight_max);
        if (ret < 0)
                return ret;

        return adp5520_store(dev, buf, count, ADP5520_DAYLIGHT_MAX);
}
static DEVICE_ATTR(daylight_max, 0664, adp5520_bl_daylight_max_show,
                        adp5520_bl_daylight_max_store);

static ssize_t adp5520_bl_dark_dim_show(struct device *dev,
                        struct device_attribute *attr, char *buf)
{
        return adp5520_show(dev, buf, ADP5520_DARK_DIM);
}

static ssize_t adp5520_bl_dark_dim_store(struct device *dev,
                        struct device_attribute *attr,
                        const char *buf, size_t count)
{
        return adp5520_store(dev, buf, count, ADP5520_DARK_DIM);
}
static DEVICE_ATTR(dark_dim, 0664, adp5520_bl_dark_dim_show,
                        adp5520_bl_dark_dim_store);

static ssize_t adp5520_bl_office_dim_show(struct device *dev,
                        struct device_attribute *attr, char *buf)
{
        return adp5520_show(dev, buf, ADP5520_OFFICE_DIM);
}

static ssize_t adp5520_bl_office_dim_store(struct device *dev,
                        struct device_attribute *attr,
                        const char *buf, size_t count)
{
        return adp5520_store(dev, buf, count, ADP5520_OFFICE_DIM);
}
static DEVICE_ATTR(office_dim, 0664, adp5520_bl_office_dim_show,
                        adp5520_bl_office_dim_store);

static ssize_t adp5520_bl_daylight_dim_show(struct device *dev,
                        struct device_attribute *attr, char *buf)
{
        return adp5520_show(dev, buf, ADP5520_DAYLIGHT_DIM);
}

static ssize_t adp5520_bl_daylight_dim_store(struct device *dev,
                        struct device_attribute *attr,
                        const char *buf, size_t count)
{
        return adp5520_store(dev, buf, count, ADP5520_DAYLIGHT_DIM);
}
static DEVICE_ATTR(daylight_dim, 0664, adp5520_bl_daylight_dim_show,
                        adp5520_bl_daylight_dim_store);

static struct attribute *adp5520_bl_attributes[] = {
        &dev_attr_dark_max.attr,
        &dev_attr_dark_dim.attr,
        &dev_attr_office_max.attr,
        &dev_attr_office_dim.attr,
        &dev_attr_daylight_max.attr,
        &dev_attr_daylight_dim.attr,
        NULL
};

static const struct attribute_group adp5520_bl_attr_group = {
        .attrs = adp5520_bl_attributes,
};

static int adp5520_bl_probe(struct platform_device *pdev)
{
        struct backlight_properties props;
        struct backlight_device *bl;
        struct adp5520_bl *data;
        int ret = 0;

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

        data->master = pdev->dev.parent;
        data->pdata = dev_get_platdata(&pdev->dev);

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

        data->id = pdev->id;
        data->current_brightness = 0;

        mutex_init(&data->lock);

        memset(&props, 0, sizeof(struct backlight_properties));
        props.type = BACKLIGHT_RAW;
        props.max_brightness = ADP5020_MAX_BRIGHTNESS;
        bl = devm_backlight_device_register(&pdev->dev, pdev->name,
                                        data->master, data, &adp5520_bl_ops,
                                        &props);
        if (IS_ERR(bl)) {
                dev_err(&pdev->dev, "failed to register backlight\n");
                return PTR_ERR(bl);
        }

        bl->props.brightness = ADP5020_MAX_BRIGHTNESS;
        if (data->pdata->en_ambl_sens)
                ret = sysfs_create_group(&bl->dev.kobj,
                        &adp5520_bl_attr_group);

        if (ret) {
                dev_err(&pdev->dev, "failed to register sysfs\n");
                return ret;
        }

        platform_set_drvdata(pdev, bl);
        ret = adp5520_bl_setup(bl);
        if (ret) {
                dev_err(&pdev->dev, "failed to setup\n");
                if (data->pdata->en_ambl_sens)
                        sysfs_remove_group(&bl->dev.kobj,
                                        &adp5520_bl_attr_group);
                return ret;
        }

        backlight_update_status(bl);

        return 0;
}

static void adp5520_bl_remove(struct platform_device *pdev)
{
        struct backlight_device *bl = platform_get_drvdata(pdev);
        struct adp5520_bl *data = bl_get_data(bl);

        adp5520_clr_bits(data->master, ADP5520_MODE_STATUS, ADP5520_BL_EN);

        if (data->pdata->en_ambl_sens)
                sysfs_remove_group(&bl->dev.kobj,
                                &adp5520_bl_attr_group);
}

#ifdef CONFIG_PM_SLEEP
static int adp5520_bl_suspend(struct device *dev)
{
        struct backlight_device *bl = dev_get_drvdata(dev);

        return adp5520_bl_set(bl, 0);
}

static int adp5520_bl_resume(struct device *dev)
{
        struct backlight_device *bl = dev_get_drvdata(dev);

        backlight_update_status(bl);
        return 0;
}
#endif

static SIMPLE_DEV_PM_OPS(adp5520_bl_pm_ops, adp5520_bl_suspend,
                        adp5520_bl_resume);

static struct platform_driver adp5520_bl_driver = {
        .driver         = {
                .name   = "adp5520-backlight",
                .pm     = &adp5520_bl_pm_ops,
        },
        .probe          = adp5520_bl_probe,
        .remove         = adp5520_bl_remove,
};

module_platform_driver(adp5520_bl_driver);

MODULE_AUTHOR("Michael Hennerich <michael.hennerich@analog.com>");
MODULE_DESCRIPTION("ADP5520(01) Backlight Driver");
MODULE_LICENSE("GPL");
MODULE_ALIAS("platform:adp5520-backlight");