adp5520_bl.c

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/*
 * Backlight driver for Analog Devices ADP5520/ADP5501 MFD PMICs
 *
 * Copyright 2009 Analog Devices Inc.
 *
 * Licensed under the GPL-2 or later.
 */

#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/platform_device.h>
#include <linux/fb.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)
{
    int brightness = bl->props.brightness;
    if (bl->props.power != FB_BLANK_UNBLANK)
        brightness = 0;

    if (bl->props.fb_blank != FB_BLANK_UNBLANK)
        brightness = 0;

    return adp5520_bl_set(bl, brightness);
}

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 error;
    uint8_t reg_val;

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

    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 __devinit 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 = pdev->dev.platform_data;

    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 = backlight_device_register(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");
        backlight_device_unregister(bl);
    }

    platform_set_drvdata(pdev, bl);
    ret |= adp5520_bl_setup(bl);
    backlight_update_status(bl);

    return ret;
}

static int __devexit 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);

    backlight_device_unregister(bl);

    return 0;
}

#ifdef CONFIG_PM
static int adp5520_bl_suspend(struct platform_device *pdev,
                 pm_message_t state)
{
    struct backlight_device *bl = platform_get_drvdata(pdev);
    return adp5520_bl_set(bl, 0);
}

static int adp5520_bl_resume(struct platform_device *pdev)
{
    struct backlight_device *bl = platform_get_drvdata(pdev);

    backlight_update_status(bl);
    return 0;
}
#else
#define adp5520_bl_suspend  NULL
#define adp5520_bl_resume   NULL
#endif

static struct platform_driver adp5520_bl_driver = {
    .driver     = {
        .name   = "adp5520-backlight",
        .owner  = THIS_MODULE,
    },
    .probe      = adp5520_bl_probe,
    .remove     = __devexit_p(adp5520_bl_remove),
    .suspend    = adp5520_bl_suspend,
    .resume     = adp5520_bl_resume,
};

module_platform_driver(adp5520_bl_driver);

MODULE_AUTHOR("Michael Hennerich <[email protected]>");
MODULE_DESCRIPTION("ADP5520(01) Backlight Driver");
MODULE_LICENSE("GPL");
MODULE_ALIAS("platform:adp5520-backlight");