backlight: new driver for the ADP8870 backlight devices

Signed-off-by: Michael Hennerich <michael.hennerich@analog.com>
Signed-off-by: Mike Frysinger <vapier@gentoo.org>
Cc: Richard Purdie <rpurdie@rpsys.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

3 files changed, 1024 insertions, 0 deletions

diff --git a/drivers/video/backlight/Kconfig b/drivers/video/backlight/Kconfig
index 0c9373bedd1f..2d93c8d61ad5 100644
--- a/drivers/video/backlight/Kconfig
+++ b/drivers/video/backlight/Kconfig
@@ -302,6 +302,18 @@ config BACKLIGHT_ADP8860
           To compile this driver as a module, choose M here: the module will
           be called adp8860_bl.
 
+config BACKLIGHT_ADP8870
+        tristate "Backlight Driver for ADP8870 using WLED"
+        depends on BACKLIGHT_CLASS_DEVICE && I2C
+        select NEW_LEDS
+        select LEDS_CLASS
+        help
+          If you have a LCD backlight connected to the ADP8870,
+          say Y here to enable this driver.
+
+          To compile this driver as a module, choose M here: the module will
+          be called adp8870_bl.
+
 config BACKLIGHT_88PM860X
         tristate "Backlight Driver for 88PM8606 using WLED"
         depends on MFD_88PM860X
diff --git a/drivers/video/backlight/Makefile b/drivers/video/backlight/Makefile
index b9ca8490df87..ee72adb8786e 100644
--- a/drivers/video/backlight/Makefile
+++ b/drivers/video/backlight/Makefile
@@ -34,6 +34,7 @@ obj-$(CONFIG_BACKLIGHT_WM831X)	+= wm831x_bl.o
 obj-$(CONFIG_BACKLIGHT_ADX)    += adx_bl.o
 obj-$(CONFIG_BACKLIGHT_ADP5520) += adp5520_bl.o
 obj-$(CONFIG_BACKLIGHT_ADP8860) += adp8860_bl.o
+obj-$(CONFIG_BACKLIGHT_ADP8870) += adp8870_bl.o
 obj-$(CONFIG_BACKLIGHT_88PM860X) += 88pm860x_bl.o
 obj-$(CONFIG_BACKLIGHT_PCF50633)        += pcf50633-backlight.o
 
diff --git a/drivers/video/backlight/adp8870_bl.c b/drivers/video/backlight/adp8870_bl.c
new file mode 100644
index 000000000000..e320b62576e2
--- /dev/null
+++ b/drivers/video/backlight/adp8870_bl.c
@@ -0,0 +1,1011 @@
+/*
+ * 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/version.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) == 0)) {
+                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 = kcalloc(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)
+                goto err_free;
+
+        ret = adp8870_write(client, ADP8870_ISCT1,
+                        (pdata->led_on_time & 0x3) << 6);
+        if (ret)
+                goto err_free;
+
+        ret = adp8870_write(client, ADP8870_ISCF,
+                        FADE_VAL(pdata->led_fade_in, pdata->led_fade_out));
+        if (ret)
+                goto err_free;
+
+        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);
+        }
+
+ err_free:
+        kfree(led);
+
+        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);
+        }
+
+        kfree(data->led);
+        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 = strict_strtoul(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 = strict_strtoul(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 = strict_strtoul(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 = kzalloc(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.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");
+                ret = PTR_ERR(bl);
+                goto out2;
+        }
+
+        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);
+out2:
+        i2c_set_clientdata(client, NULL);
+        kfree(data);
+
+        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);
+        i2c_set_clientdata(client, NULL);
+        kfree(data);
+
+        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,
+};
+
+static int __init adp8870_init(void)
+{
+        return i2c_add_driver(&adp8870_driver);
+}
+module_init(adp8870_init);
+
+static void __exit adp8870_exit(void)
+{
+        i2c_del_driver(&adp8870_driver);
+}
+module_exit(adp8870_exit);
+
+MODULE_LICENSE("GPL v2");
+MODULE_AUTHOR("Michael Hennerich <hennerich@blackfin.uclinux.org>");
+MODULE_DESCRIPTION("ADP8870 Backlight driver");
+MODULE_ALIAS("platform:adp8870-backlight");