adp8870_bl.c

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/*
 * Backlight driver for Analog Devices ADP8870 Backlight Devices
 *
 * Copyright 2009-2011 Analog Devices Inc.
 *
 * Licensed under the GPL-2 or later.
 */

#include <linux/module.h>
#include <linux/init.h>
#include <linux/errno.h>
#include <linux/pm.h>
#include <linux/platform_device.h>
#include <linux/i2c.h>
#include <linux/fb.h>
#include <linux/backlight.h>
#include <linux/leds.h>
#include <linux/workqueue.h>
#include <linux/slab.h>

#include <linux/i2c/adp8870.h>
#define ADP8870_EXT_FEATURES
#define ADP8870_USE_LEDS


#define ADP8870_MFDVID  0x00  /* Manufacturer and device ID */
#define ADP8870_MDCR    0x01  /* Device mode and status */
#define ADP8870_INT_STAT 0x02  /* Interrupts status */
#define ADP8870_INT_EN  0x03  /* Interrupts enable */
#define ADP8870_CFGR    0x04  /* Configuration register */
#define ADP8870_BLSEL   0x05  /* Sink enable backlight or independent */
#define ADP8870_PWMLED  0x06  /* PWM Enable Selection Register */
#define ADP8870_BLOFF   0x07  /* Backlight off timeout */
#define ADP8870_BLDIM   0x08  /* Backlight dim timeout */
#define ADP8870_BLFR    0x09  /* Backlight fade in and out rates */
#define ADP8870_BLMX1   0x0A  /* Backlight (Brightness Level 1-daylight) maximum current */
#define ADP8870_BLDM1   0x0B  /* Backlight (Brightness Level 1-daylight) dim current */
#define ADP8870_BLMX2   0x0C  /* Backlight (Brightness Level 2-bright) maximum current */
#define ADP8870_BLDM2   0x0D  /* Backlight (Brightness Level 2-bright) dim current */
#define ADP8870_BLMX3   0x0E  /* Backlight (Brightness Level 3-office) maximum current */
#define ADP8870_BLDM3   0x0F  /* Backlight (Brightness Level 3-office) dim current */
#define ADP8870_BLMX4   0x10  /* Backlight (Brightness Level 4-indoor) maximum current */
#define ADP8870_BLDM4   0x11  /* Backlight (Brightness Level 4-indoor) dim current */
#define ADP8870_BLMX5   0x12  /* Backlight (Brightness Level 5-dark) maximum current */
#define ADP8870_BLDM5   0x13  /* Backlight (Brightness Level 5-dark) dim current */
#define ADP8870_ISCLAW  0x1A  /* Independent sink current fade law register */
#define ADP8870_ISCC    0x1B  /* Independent sink current control register */
#define ADP8870_ISCT1   0x1C  /* Independent Sink Current Timer Register LED[7:5] */
#define ADP8870_ISCT2   0x1D  /* Independent Sink Current Timer Register LED[4:1] */
#define ADP8870_ISCF    0x1E  /* Independent sink current fade register */
#define ADP8870_ISC1    0x1F  /* Independent Sink Current LED1 */
#define ADP8870_ISC2    0x20  /* Independent Sink Current LED2 */
#define ADP8870_ISC3    0x21  /* Independent Sink Current LED3 */
#define ADP8870_ISC4    0x22  /* Independent Sink Current LED4 */
#define ADP8870_ISC5    0x23  /* Independent Sink Current LED5 */
#define ADP8870_ISC6    0x24  /* Independent Sink Current LED6 */
#define ADP8870_ISC7    0x25  /* Independent Sink Current LED7 (Brightness Level 1-daylight) */
#define ADP8870_ISC7_L2 0x26  /* Independent Sink Current LED7 (Brightness Level 2-bright) */
#define ADP8870_ISC7_L3 0x27  /* Independent Sink Current LED7 (Brightness Level 3-office) */
#define ADP8870_ISC7_L4 0x28  /* Independent Sink Current LED7 (Brightness Level 4-indoor) */
#define ADP8870_ISC7_L5 0x29  /* Independent Sink Current LED7 (Brightness Level 5-dark) */
#define ADP8870_CMP_CTL 0x2D  /* ALS Comparator Control Register */
#define ADP8870_ALS1_EN 0x2E  /* Main ALS comparator level enable */
#define ADP8870_ALS2_EN 0x2F  /* Second ALS comparator level enable */
#define ADP8870_ALS1_STAT 0x30  /* Main ALS Comparator Status Register */
#define ADP8870_ALS2_STAT 0x31  /* Second ALS Comparator Status Register */
#define ADP8870_L2TRP   0x32  /* L2 comparator reference */
#define ADP8870_L2HYS   0x33  /* L2 hysteresis */
#define ADP8870_L3TRP   0x34  /* L3 comparator reference */
#define ADP8870_L3HYS   0x35  /* L3 hysteresis */
#define ADP8870_L4TRP   0x36  /* L4 comparator reference */
#define ADP8870_L4HYS   0x37  /* L4 hysteresis */
#define ADP8870_L5TRP   0x38  /* L5 comparator reference */
#define ADP8870_L5HYS   0x39  /* L5 hysteresis */
#define ADP8870_PH1LEVL 0x40  /* First phototransistor ambient light level-low byte register */
#define ADP8870_PH1LEVH 0x41  /* First phototransistor ambient light level-high byte register */
#define ADP8870_PH2LEVL 0x42  /* Second phototransistor ambient light level-low byte register */
#define ADP8870_PH2LEVH 0x43  /* Second phototransistor ambient light level-high byte register */

#define ADP8870_MANUFID     0x3  /* Analog Devices AD8870 Manufacturer and device ID */
#define ADP8870_DEVID(x)    ((x) & 0xF)
#define ADP8870_MANID(x)    ((x) >> 4)

/* MDCR Device mode and status */
#define D7ALSEN         (1 << 7)
#define INT_CFG         (1 << 6)
#define NSTBY           (1 << 5)
#define DIM_EN          (1 << 4)
#define GDWN_DIS        (1 << 3)
#define SIS_EN          (1 << 2)
#define CMP_AUTOEN      (1 << 1)
#define BLEN            (1 << 0)

/* ADP8870_ALS1_EN Main ALS comparator level enable */
#define L5_EN           (1 << 3)
#define L4_EN           (1 << 2)
#define L3_EN           (1 << 1)
#define L2_EN           (1 << 0)

#define CFGR_BLV_SHIFT      3
#define CFGR_BLV_MASK       0x7
#define ADP8870_FLAG_LED_MASK   0xFF

#define FADE_VAL(in, out)   ((0xF & (in)) | ((0xF & (out)) << 4))
#define BL_CFGR_VAL(law, blv)   ((((blv) & CFGR_BLV_MASK) << CFGR_BLV_SHIFT) | ((0x3 & (law)) << 1))
#define ALS_CMPR_CFG_VAL(filt)  ((0x7 & (filt)) << 1)

struct adp8870_bl {
    struct i2c_client *client;
    struct backlight_device *bl;
    struct adp8870_led *led;
    struct adp8870_backlight_platform_data *pdata;
    struct mutex lock;
    unsigned long cached_daylight_max;
    int id;
    int revid;
    int current_brightness;
};

struct adp8870_led {
    struct led_classdev cdev;
    struct work_struct  work;
    struct i2c_client   *client;
    enum led_brightness new_brightness;
    int         id;
    int         flags;
};

static int adp8870_read(struct i2c_client *client, int reg, uint8_t *val)
{
    int ret;

    ret = i2c_smbus_read_byte_data(client, reg);
    if (ret < 0) {
        dev_err(&client->dev, "failed reading at 0x%02x\n", reg);
        return ret;
    }

    *val = ret;
    return 0;
}


static int adp8870_write(struct i2c_client *client, u8 reg, u8 val)
{
    int ret = i2c_smbus_write_byte_data(client, reg, val);
    if (ret)
        dev_err(&client->dev, "failed to write\n");

    return ret;
}

static int adp8870_set_bits(struct i2c_client *client, int reg, uint8_t bit_mask)
{
    struct adp8870_bl *data = i2c_get_clientdata(client);
    uint8_t reg_val;
    int ret;

    mutex_lock(&data->lock);

    ret = adp8870_read(client, reg, &reg_val);

    if (!ret && ((reg_val & bit_mask) != bit_mask)) {
        reg_val |= bit_mask;
        ret = adp8870_write(client, reg, reg_val);
    }

    mutex_unlock(&data->lock);
    return ret;
}

static int adp8870_clr_bits(struct i2c_client *client, int reg, uint8_t bit_mask)
{
    struct adp8870_bl *data = i2c_get_clientdata(client);
    uint8_t reg_val;
    int ret;

    mutex_lock(&data->lock);

    ret = adp8870_read(client, reg, &reg_val);

    if (!ret && (reg_val & bit_mask)) {
        reg_val &= ~bit_mask;
        ret = adp8870_write(client, reg, reg_val);
    }

    mutex_unlock(&data->lock);
    return ret;
}

/*
 * Independent sink / LED
 */
#if defined(ADP8870_USE_LEDS)
static void adp8870_led_work(struct work_struct *work)
{
    struct adp8870_led *led = container_of(work, struct adp8870_led, work);
    adp8870_write(led->client, ADP8870_ISC1 + led->id - 1,
             led->new_brightness >> 1);
}

static void adp8870_led_set(struct led_classdev *led_cdev,
               enum led_brightness value)
{
    struct adp8870_led *led;

    led = container_of(led_cdev, struct adp8870_led, cdev);
    led->new_brightness = value;
    /*
     * Use workqueue for IO since I2C operations can sleep.
     */
    schedule_work(&led->work);
}

static int adp8870_led_setup(struct adp8870_led *led)
{
    struct i2c_client *client = led->client;
    int ret = 0;

    ret = adp8870_write(client, ADP8870_ISC1 + led->id - 1, 0);
    if (ret)
        return ret;

    ret = adp8870_set_bits(client, ADP8870_ISCC, 1 << (led->id - 1));
    if (ret)
        return ret;

    if (led->id > 4)
        ret = adp8870_set_bits(client, ADP8870_ISCT1,
                (led->flags & 0x3) << ((led->id - 5) * 2));
    else
        ret = adp8870_set_bits(client, ADP8870_ISCT2,
                (led->flags & 0x3) << ((led->id - 1) * 2));

    return ret;
}

static int __devinit adp8870_led_probe(struct i2c_client *client)
{
    struct adp8870_backlight_platform_data *pdata =
        client->dev.platform_data;
    struct adp8870_bl *data = i2c_get_clientdata(client);
    struct adp8870_led *led, *led_dat;
    struct led_info *cur_led;
    int ret, i;

    led = devm_kzalloc(&client->dev, pdata->num_leds * sizeof(*led),
                GFP_KERNEL);
    if (led == NULL) {
        dev_err(&client->dev, "failed to alloc memory\n");
        return -ENOMEM;
    }

    ret = adp8870_write(client, ADP8870_ISCLAW, pdata->led_fade_law);
    if (ret)
        return ret;

    ret = adp8870_write(client, ADP8870_ISCT1,
            (pdata->led_on_time & 0x3) << 6);
    if (ret)
        return ret;

    ret = adp8870_write(client, ADP8870_ISCF,
            FADE_VAL(pdata->led_fade_in, pdata->led_fade_out));
    if (ret)
        return ret;

    for (i = 0; i < pdata->num_leds; ++i) {
        cur_led = &pdata->leds[i];
        led_dat = &led[i];

        led_dat->id = cur_led->flags & ADP8870_FLAG_LED_MASK;

        if (led_dat->id > 7 || led_dat->id < 1) {
            dev_err(&client->dev, "Invalid LED ID %d\n",
                led_dat->id);
            goto err;
        }

        if (pdata->bl_led_assign & (1 << (led_dat->id - 1))) {
            dev_err(&client->dev, "LED %d used by Backlight\n",
                led_dat->id);
            goto err;
        }

        led_dat->cdev.name = cur_led->name;
        led_dat->cdev.default_trigger = cur_led->default_trigger;
        led_dat->cdev.brightness_set = adp8870_led_set;
        led_dat->cdev.brightness = LED_OFF;
        led_dat->flags = cur_led->flags >> FLAG_OFFT_SHIFT;
        led_dat->client = client;
        led_dat->new_brightness = LED_OFF;
        INIT_WORK(&led_dat->work, adp8870_led_work);

        ret = led_classdev_register(&client->dev, &led_dat->cdev);
        if (ret) {
            dev_err(&client->dev, "failed to register LED %d\n",
                led_dat->id);
            goto err;
        }

        ret = adp8870_led_setup(led_dat);
        if (ret) {
            dev_err(&client->dev, "failed to write\n");
            i++;
            goto err;
        }
    }

    data->led = led;

    return 0;

 err:
    for (i = i - 1; i >= 0; --i) {
        led_classdev_unregister(&led[i].cdev);
        cancel_work_sync(&led[i].work);
    }

    return ret;
}

static int __devexit adp8870_led_remove(struct i2c_client *client)
{
    struct adp8870_backlight_platform_data *pdata =
        client->dev.platform_data;
    struct adp8870_bl *data = i2c_get_clientdata(client);
    int i;

    for (i = 0; i < pdata->num_leds; i++) {
        led_classdev_unregister(&data->led[i].cdev);
        cancel_work_sync(&data->led[i].work);
    }

    return 0;
}
#else
static int __devinit adp8870_led_probe(struct i2c_client *client)
{
    return 0;
}

static int __devexit adp8870_led_remove(struct i2c_client *client)
{
    return 0;
}
#endif

static int adp8870_bl_set(struct backlight_device *bl, int brightness)
{
    struct adp8870_bl *data = bl_get_data(bl);
    struct i2c_client *client = data->client;
    int ret = 0;

    if (data->pdata->en_ambl_sens) {
        if ((brightness > 0) && (brightness < ADP8870_MAX_BRIGHTNESS)) {
            /* Disable Ambient Light auto adjust */
            ret = adp8870_clr_bits(client, ADP8870_MDCR,
                    CMP_AUTOEN);
            if (ret)
                return ret;
            ret = adp8870_write(client, ADP8870_BLMX1, brightness);
            if (ret)
                return ret;
        } else {
            /*
             * MAX_BRIGHTNESS -> Enable Ambient Light auto adjust
             * restore daylight l1 sysfs brightness
             */
            ret = adp8870_write(client, ADP8870_BLMX1,
                     data->cached_daylight_max);
            if (ret)
                return ret;

            ret = adp8870_set_bits(client, ADP8870_MDCR,
                     CMP_AUTOEN);
            if (ret)
                return ret;
        }
    } else {
        ret = adp8870_write(client, ADP8870_BLMX1, brightness);
        if (ret)
            return ret;
    }

    if (data->current_brightness && brightness == 0)
        ret = adp8870_set_bits(client,
                ADP8870_MDCR, DIM_EN);
    else if (data->current_brightness == 0 && brightness)
        ret = adp8870_clr_bits(client,
                ADP8870_MDCR, DIM_EN);

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

    return ret;
}

static int adp8870_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 adp8870_bl_set(bl, brightness);
}

static int adp8870_bl_get_brightness(struct backlight_device *bl)
{
    struct adp8870_bl *data = bl_get_data(bl);

    return data->current_brightness;
}

static const struct backlight_ops adp8870_bl_ops = {
    .update_status  = adp8870_bl_update_status,
    .get_brightness = adp8870_bl_get_brightness,
};

static int adp8870_bl_setup(struct backlight_device *bl)
{
    struct adp8870_bl *data = bl_get_data(bl);
    struct i2c_client *client = data->client;
    struct adp8870_backlight_platform_data *pdata = data->pdata;
    int ret = 0;

    ret = adp8870_write(client, ADP8870_BLSEL, ~pdata->bl_led_assign);
    if (ret)
        return ret;

    ret = adp8870_write(client, ADP8870_PWMLED, pdata->pwm_assign);
    if (ret)
        return ret;

    ret = adp8870_write(client, ADP8870_BLMX1, pdata->l1_daylight_max);
    if (ret)
        return ret;

    ret = adp8870_write(client, ADP8870_BLDM1, pdata->l1_daylight_dim);
    if (ret)
        return ret;

    if (pdata->en_ambl_sens) {
        data->cached_daylight_max = pdata->l1_daylight_max;
        ret = adp8870_write(client, ADP8870_BLMX2,
                        pdata->l2_bright_max);
        if (ret)
            return ret;
        ret = adp8870_write(client, ADP8870_BLDM2,
                        pdata->l2_bright_dim);
        if (ret)
            return ret;

        ret = adp8870_write(client, ADP8870_BLMX3,
                        pdata->l3_office_max);
        if (ret)
            return ret;
        ret = adp8870_write(client, ADP8870_BLDM3,
                        pdata->l3_office_dim);
        if (ret)
            return ret;

        ret = adp8870_write(client, ADP8870_BLMX4,
                        pdata->l4_indoor_max);
        if (ret)
            return ret;

        ret = adp8870_write(client, ADP8870_BLDM4,
                        pdata->l4_indor_dim);
        if (ret)
            return ret;

        ret = adp8870_write(client, ADP8870_BLMX5,
                        pdata->l5_dark_max);
        if (ret)
            return ret;

        ret = adp8870_write(client, ADP8870_BLDM5,
                        pdata->l5_dark_dim);
        if (ret)
            return ret;

        ret = adp8870_write(client, ADP8870_L2TRP, pdata->l2_trip);
        if (ret)
            return ret;

        ret = adp8870_write(client, ADP8870_L2HYS, pdata->l2_hyst);
        if (ret)
            return ret;

        ret = adp8870_write(client, ADP8870_L3TRP, pdata->l3_trip);
        if (ret)
            return ret;

        ret = adp8870_write(client, ADP8870_L3HYS, pdata->l3_hyst);
        if (ret)
            return ret;

        ret = adp8870_write(client, ADP8870_L4TRP, pdata->l4_trip);
        if (ret)
            return ret;

        ret = adp8870_write(client, ADP8870_L4HYS, pdata->l4_hyst);
        if (ret)
            return ret;

        ret = adp8870_write(client, ADP8870_L5TRP, pdata->l5_trip);
        if (ret)
            return ret;

        ret = adp8870_write(client, ADP8870_L5HYS, pdata->l5_hyst);
        if (ret)
            return ret;

        ret = adp8870_write(client, ADP8870_ALS1_EN, L5_EN | L4_EN |
                        L3_EN | L2_EN);
        if (ret)
            return ret;

        ret = adp8870_write(client, ADP8870_CMP_CTL,
            ALS_CMPR_CFG_VAL(pdata->abml_filt));
        if (ret)
            return ret;
    }

    ret = adp8870_write(client, ADP8870_CFGR,
            BL_CFGR_VAL(pdata->bl_fade_law, 0));
    if (ret)
        return ret;

    ret = adp8870_write(client, ADP8870_BLFR, FADE_VAL(pdata->bl_fade_in,
            pdata->bl_fade_out));
    if (ret)
        return ret;
    /*
     * ADP8870 Rev0 requires GDWN_DIS bit set
     */

    ret = adp8870_set_bits(client, ADP8870_MDCR, BLEN | DIM_EN | NSTBY |
            (data->revid == 0 ? GDWN_DIS : 0));

    return ret;
}

static ssize_t adp8870_show(struct device *dev, char *buf, int reg)
{
    struct adp8870_bl *data = dev_get_drvdata(dev);
    int error;
    uint8_t reg_val;

    mutex_lock(&data->lock);
    error = adp8870_read(data->client, reg, &reg_val);
    mutex_unlock(&data->lock);

    if (error < 0)
        return error;

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

static ssize_t adp8870_store(struct device *dev, const char *buf,
             size_t count, int reg)
{
    struct adp8870_bl *data = dev_get_drvdata(dev);
    unsigned long val;
    int ret;

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

    mutex_lock(&data->lock);
    adp8870_write(data->client, reg, val);
    mutex_unlock(&data->lock);

    return count;
}

static ssize_t adp8870_bl_l5_dark_max_show(struct device *dev,
        struct device_attribute *attr, char *buf)
{
    return adp8870_show(dev, buf, ADP8870_BLMX5);
}

static ssize_t adp8870_bl_l5_dark_max_store(struct device *dev,
        struct device_attribute *attr, const char *buf, size_t count)
{
    return adp8870_store(dev, buf, count, ADP8870_BLMX5);
}
static DEVICE_ATTR(l5_dark_max, 0664, adp8870_bl_l5_dark_max_show,
            adp8870_bl_l5_dark_max_store);


static ssize_t adp8870_bl_l4_indoor_max_show(struct device *dev,
        struct device_attribute *attr, char *buf)
{
    return adp8870_show(dev, buf, ADP8870_BLMX4);
}

static ssize_t adp8870_bl_l4_indoor_max_store(struct device *dev,
        struct device_attribute *attr, const char *buf, size_t count)
{
    return adp8870_store(dev, buf, count, ADP8870_BLMX4);
}
static DEVICE_ATTR(l4_indoor_max, 0664, adp8870_bl_l4_indoor_max_show,
            adp8870_bl_l4_indoor_max_store);


static ssize_t adp8870_bl_l3_office_max_show(struct device *dev,
                     struct device_attribute *attr, char *buf)
{
    return adp8870_show(dev, buf, ADP8870_BLMX3);
}

static ssize_t adp8870_bl_l3_office_max_store(struct device *dev,
        struct device_attribute *attr, const char *buf, size_t count)
{
    return adp8870_store(dev, buf, count, ADP8870_BLMX3);
}

static DEVICE_ATTR(l3_office_max, 0664, adp8870_bl_l3_office_max_show,
            adp8870_bl_l3_office_max_store);

static ssize_t adp8870_bl_l2_bright_max_show(struct device *dev,
        struct device_attribute *attr, char *buf)
{
    return adp8870_show(dev, buf, ADP8870_BLMX2);
}

static ssize_t adp8870_bl_l2_bright_max_store(struct device *dev,
        struct device_attribute *attr, const char *buf, size_t count)
{
    return adp8870_store(dev, buf, count, ADP8870_BLMX2);
}
static DEVICE_ATTR(l2_bright_max, 0664, adp8870_bl_l2_bright_max_show,
            adp8870_bl_l2_bright_max_store);

static ssize_t adp8870_bl_l1_daylight_max_show(struct device *dev,
            struct device_attribute *attr, char *buf)
{
    return adp8870_show(dev, buf, ADP8870_BLMX1);
}

static ssize_t adp8870_bl_l1_daylight_max_store(struct device *dev,
        struct device_attribute *attr, const char *buf, size_t count)
{
    struct adp8870_bl *data = dev_get_drvdata(dev);
    int ret = kstrtoul(buf, 10, &data->cached_daylight_max);
    if (ret)
        return ret;

    return adp8870_store(dev, buf, count, ADP8870_BLMX1);
}
static DEVICE_ATTR(l1_daylight_max, 0664, adp8870_bl_l1_daylight_max_show,
            adp8870_bl_l1_daylight_max_store);

static ssize_t adp8870_bl_l5_dark_dim_show(struct device *dev,
            struct device_attribute *attr, char *buf)
{
    return adp8870_show(dev, buf, ADP8870_BLDM5);
}

static ssize_t adp8870_bl_l5_dark_dim_store(struct device *dev,
                     struct device_attribute *attr,
                     const char *buf, size_t count)
{
    return adp8870_store(dev, buf, count, ADP8870_BLDM5);
}
static DEVICE_ATTR(l5_dark_dim, 0664, adp8870_bl_l5_dark_dim_show,
            adp8870_bl_l5_dark_dim_store);

static ssize_t adp8870_bl_l4_indoor_dim_show(struct device *dev,
            struct device_attribute *attr, char *buf)
{
    return adp8870_show(dev, buf, ADP8870_BLDM4);
}

static ssize_t adp8870_bl_l4_indoor_dim_store(struct device *dev,
                     struct device_attribute *attr,
                     const char *buf, size_t count)
{
    return adp8870_store(dev, buf, count, ADP8870_BLDM4);
}
static DEVICE_ATTR(l4_indoor_dim, 0664, adp8870_bl_l4_indoor_dim_show,
            adp8870_bl_l4_indoor_dim_store);


static ssize_t adp8870_bl_l3_office_dim_show(struct device *dev,
            struct device_attribute *attr, char *buf)
{
    return adp8870_show(dev, buf, ADP8870_BLDM3);
}

static ssize_t adp8870_bl_l3_office_dim_store(struct device *dev,
                     struct device_attribute *attr,
                     const char *buf, size_t count)
{
    return adp8870_store(dev, buf, count, ADP8870_BLDM3);
}
static DEVICE_ATTR(l3_office_dim, 0664, adp8870_bl_l3_office_dim_show,
            adp8870_bl_l3_office_dim_store);

static ssize_t adp8870_bl_l2_bright_dim_show(struct device *dev,
            struct device_attribute *attr, char *buf)
{
    return adp8870_show(dev, buf, ADP8870_BLDM2);
}

static ssize_t adp8870_bl_l2_bright_dim_store(struct device *dev,
                     struct device_attribute *attr,
                     const char *buf, size_t count)
{
    return adp8870_store(dev, buf, count, ADP8870_BLDM2);
}
static DEVICE_ATTR(l2_bright_dim, 0664, adp8870_bl_l2_bright_dim_show,
            adp8870_bl_l2_bright_dim_store);

static ssize_t adp8870_bl_l1_daylight_dim_show(struct device *dev,
                     struct device_attribute *attr, char *buf)
{
    return adp8870_show(dev, buf, ADP8870_BLDM1);
}

static ssize_t adp8870_bl_l1_daylight_dim_store(struct device *dev,
                     struct device_attribute *attr,
                     const char *buf, size_t count)
{
    return adp8870_store(dev, buf, count, ADP8870_BLDM1);
}
static DEVICE_ATTR(l1_daylight_dim, 0664, adp8870_bl_l1_daylight_dim_show,
            adp8870_bl_l1_daylight_dim_store);

#ifdef ADP8870_EXT_FEATURES
static ssize_t adp8870_bl_ambient_light_level_show(struct device *dev,
                     struct device_attribute *attr, char *buf)
{
    struct adp8870_bl *data = dev_get_drvdata(dev);
    int error;
    uint8_t reg_val;
    uint16_t ret_val;

    mutex_lock(&data->lock);
    error = adp8870_read(data->client, ADP8870_PH1LEVL, &reg_val);
    if (error < 0) {
        mutex_unlock(&data->lock);
        return error;
    }
    ret_val = reg_val;
    error = adp8870_read(data->client, ADP8870_PH1LEVH, &reg_val);
    mutex_unlock(&data->lock);

    if (error < 0)
        return error;

    /* Return 13-bit conversion value for the first light sensor */
    ret_val += (reg_val & 0x1F) << 8;

    return sprintf(buf, "%u\n", ret_val);
}
static DEVICE_ATTR(ambient_light_level, 0444,
        adp8870_bl_ambient_light_level_show, NULL);

static ssize_t adp8870_bl_ambient_light_zone_show(struct device *dev,
                     struct device_attribute *attr, char *buf)
{
    struct adp8870_bl *data = dev_get_drvdata(dev);
    int error;
    uint8_t reg_val;

    mutex_lock(&data->lock);
    error = adp8870_read(data->client, ADP8870_CFGR, &reg_val);
    mutex_unlock(&data->lock);

    if (error < 0)
        return error;

    return sprintf(buf, "%u\n",
        ((reg_val >> CFGR_BLV_SHIFT) & CFGR_BLV_MASK) + 1);
}

static ssize_t adp8870_bl_ambient_light_zone_store(struct device *dev,
                     struct device_attribute *attr,
                     const char *buf, size_t count)
{
    struct adp8870_bl *data = dev_get_drvdata(dev);
    unsigned long val;
    uint8_t reg_val;
    int ret;

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

    if (val == 0) {
        /* Enable automatic ambient light sensing */
        adp8870_set_bits(data->client, ADP8870_MDCR, CMP_AUTOEN);
    } else if ((val > 0) && (val < 6)) {
        /* Disable automatic ambient light sensing */
        adp8870_clr_bits(data->client, ADP8870_MDCR, CMP_AUTOEN);

        /* Set user supplied ambient light zone */
        mutex_lock(&data->lock);
        adp8870_read(data->client, ADP8870_CFGR, &reg_val);
        reg_val &= ~(CFGR_BLV_MASK << CFGR_BLV_SHIFT);
        reg_val |= (val - 1) << CFGR_BLV_SHIFT;
        adp8870_write(data->client, ADP8870_CFGR, reg_val);
        mutex_unlock(&data->lock);
    }

    return count;
}
static DEVICE_ATTR(ambient_light_zone, 0664,
        adp8870_bl_ambient_light_zone_show,
        adp8870_bl_ambient_light_zone_store);
#endif

static struct attribute *adp8870_bl_attributes[] = {
    &dev_attr_l5_dark_max.attr,
    &dev_attr_l5_dark_dim.attr,
    &dev_attr_l4_indoor_max.attr,
    &dev_attr_l4_indoor_dim.attr,
    &dev_attr_l3_office_max.attr,
    &dev_attr_l3_office_dim.attr,
    &dev_attr_l2_bright_max.attr,
    &dev_attr_l2_bright_dim.attr,
    &dev_attr_l1_daylight_max.attr,
    &dev_attr_l1_daylight_dim.attr,
#ifdef ADP8870_EXT_FEATURES
    &dev_attr_ambient_light_level.attr,
    &dev_attr_ambient_light_zone.attr,
#endif
    NULL
};

static const struct attribute_group adp8870_bl_attr_group = {
    .attrs = adp8870_bl_attributes,
};

static int __devinit adp8870_probe(struct i2c_client *client,
                    const struct i2c_device_id *id)
{
    struct backlight_properties props;
    struct backlight_device *bl;
    struct adp8870_bl *data;
    struct adp8870_backlight_platform_data *pdata =
        client->dev.platform_data;
    uint8_t reg_val;
    int ret;

    if (!i2c_check_functionality(client->adapter,
                    I2C_FUNC_SMBUS_BYTE_DATA)) {
        dev_err(&client->dev, "SMBUS Byte Data not Supported\n");
        return -EIO;
    }

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

    ret = adp8870_read(client, ADP8870_MFDVID, &reg_val);
    if (ret < 0)
        return -EIO;

    if (ADP8870_MANID(reg_val) != ADP8870_MANUFID) {
        dev_err(&client->dev, "failed to probe\n");
        return -ENODEV;
    }

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

    data->revid = ADP8870_DEVID(reg_val);
    data->client = client;
    data->pdata = pdata;
    data->id = id->driver_data;
    data->current_brightness = 0;
    i2c_set_clientdata(client, data);

    mutex_init(&data->lock);

    memset(&props, 0, sizeof(props));
    props.type = BACKLIGHT_RAW;
    props.max_brightness = props.brightness = ADP8870_MAX_BRIGHTNESS;
    bl = backlight_device_register(dev_driver_string(&client->dev),
            &client->dev, data, &adp8870_bl_ops, &props);
    if (IS_ERR(bl)) {
        dev_err(&client->dev, "failed to register backlight\n");
        return PTR_ERR(bl);
    }

    data->bl = bl;

    if (pdata->en_ambl_sens)
        ret = sysfs_create_group(&bl->dev.kobj,
            &adp8870_bl_attr_group);

    if (ret) {
        dev_err(&client->dev, "failed to register sysfs\n");
        goto out1;
    }

    ret = adp8870_bl_setup(bl);
    if (ret) {
        ret = -EIO;
        goto out;
    }

    backlight_update_status(bl);

    dev_info(&client->dev, "Rev.%d Backlight\n", data->revid);

    if (pdata->num_leds)
        adp8870_led_probe(client);

    return 0;

out:
    if (data->pdata->en_ambl_sens)
        sysfs_remove_group(&data->bl->dev.kobj,
            &adp8870_bl_attr_group);
out1:
    backlight_device_unregister(bl);

    return ret;
}

static int __devexit adp8870_remove(struct i2c_client *client)
{
    struct adp8870_bl *data = i2c_get_clientdata(client);

    adp8870_clr_bits(client, ADP8870_MDCR, NSTBY);

    if (data->led)
        adp8870_led_remove(client);

    if (data->pdata->en_ambl_sens)
        sysfs_remove_group(&data->bl->dev.kobj,
            &adp8870_bl_attr_group);

    backlight_device_unregister(data->bl);

    return 0;
}

#ifdef CONFIG_PM
static int adp8870_i2c_suspend(struct i2c_client *client, pm_message_t message)
{
    adp8870_clr_bits(client, ADP8870_MDCR, NSTBY);

    return 0;
}

static int adp8870_i2c_resume(struct i2c_client *client)
{
    adp8870_set_bits(client, ADP8870_MDCR, NSTBY);

    return 0;
}
#else
#define adp8870_i2c_suspend NULL
#define adp8870_i2c_resume NULL
#endif

static const struct i2c_device_id adp8870_id[] = {
    { "adp8870", 0 },
    { }
};
MODULE_DEVICE_TABLE(i2c, adp8870_id);

static struct i2c_driver adp8870_driver = {
    .driver = {
        .name = KBUILD_MODNAME,
    },
    .probe    = adp8870_probe,
    .remove   = __devexit_p(adp8870_remove),
    .suspend = adp8870_i2c_suspend,
    .resume  = adp8870_i2c_resume,
    .id_table = adp8870_id,
};

module_i2c_driver(adp8870_driver);

MODULE_LICENSE("GPL v2");
MODULE_AUTHOR("Michael Hennerich <[email protected]>");
MODULE_DESCRIPTION("ADP8870 Backlight driver");
MODULE_ALIAS("i2c:adp8870-backlight");