ENGR00139383-1 Add ISL29023 light sensor support

This patch adds ISL29023 light sensor support.
Users may control the light sensor work at
different modes/ranges/resolutions or read
the lux value via sysfs.
A power state node is also created in sysfs.
If the light sensor works at ALS once mode,
users need to power down/power up the sensor
before read the lux value again.
Currently, IR(Infra Red) mode is not supported.

Signed-off-by: Liu Ying <Ying.Liu@freescale.com>

3 files changed, 1033 insertions, 0 deletions

diff --git a/drivers/input/misc/Kconfig b/drivers/input/misc/Kconfig
index e407e142ccca..2de3a98136eb 100644
--- a/drivers/input/misc/Kconfig
+++ b/drivers/input/misc/Kconfig
@@ -400,4 +400,13 @@ config INPUT_DA9052_ONKEY
 	  To compile this driver as a module, choose M here: the module
 	  will be called da9052_onkey.
 
+config INPUT_ISL29023
+	tristate "Intersil ISL29023 ambient light sensor"
+	depends on I2C && SYSFS
+	help
+	  If you say yes here you get support for the Intersil ISL29023
+	  ambient light sensor.
+
+	  This driver can also be built as a module.  If so, the module
+	  will be called isl29023.
 endif
diff --git a/drivers/input/misc/Makefile b/drivers/input/misc/Makefile
index c8231a783221..1ab63a7d379f 100644
--- a/drivers/input/misc/Makefile
+++ b/drivers/input/misc/Makefile
@@ -38,3 +38,4 @@ obj-$(CONFIG_INPUT_WISTRON_BTNS)	+= wistron_btns.o
 obj-$(CONFIG_INPUT_WM831X_ON)		+= wm831x-on.o
 obj-$(CONFIG_INPUT_YEALINK)		+= yealink.o
 obj-$(CONFIG_INPUT_DA9052_ONKEY)	+= da9052_onkey.o
+obj-$(CONFIG_INPUT_ISL29023)		+= isl29023.o
diff --git a/drivers/input/misc/isl29023.c b/drivers/input/misc/isl29023.c
new file mode 100644
index 000000000000..626a8b8e07ee
--- /dev/null
+++ b/drivers/input/misc/isl29023.c
@@ -0,0 +1,1023 @@
+/*
+ * Copyright (C) 2011 Freescale Semiconductor, Inc. All Rights Reserved.
+ */
+
+/*
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ */
+
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/slab.h>
+#include <linux/i2c.h>
+#include <linux/input.h>
+#include <linux/interrupt.h>
+#include <linux/irq.h>
+#include <linux/mutex.h>
+#include <linux/delay.h>
+#include <linux/isl29023.h>
+#include <linux/fsl_devices.h>
+
+#define ISL29023_DRV_NAME	"isl29023"
+#define DRIVER_VERSION		"1.0"
+
+#define ISL29023_COMMAND1		0x00
+#define ISL29023_MODE_SHIFT		(5)
+#define ISL29023_MODE_MASK		(0x7 << ISL29023_MODE_SHIFT)
+#define ISL29023_INT_FLAG_SHIFT		(2)
+#define ISL29023_INT_FLAG_MASK		(0x1 << ISL29023_INT_FLAG_SHIFT)
+#define ISL29023_INT_PERSISTS_SHIFT	(0)
+#define ISL29023_INT_PERSISTS_MASK	(0x3 << ISL29023_INT_PERSISTS_SHIFT)
+
+#define ISL29023_COMMAND2		0x01
+#define ISL29023_RES_SHIFT		(2)
+#define ISL29023_RES_MASK		(0x3 << ISL29023_RES_SHIFT)
+#define ISL29023_RANGE_SHIFT		(0)
+#define ISL29023_RANGE_MASK		(0x3 << ISL29023_RANGE_SHIFT)
+
+#define ISL29023_REG_LSB_SENSOR		0x02
+#define ISL29023_REG_MSB_SENSOR		0x03
+#define ISL29023_REG_IRQ_TH_LO_LSB	0x04
+#define ISL29023_REG_IRQ_TH_LO_MSB	0x05
+#define ISL29023_REG_IRQ_TH_HI_LSB	0x06
+#define ISL29023_REG_IRQ_TH_HI_MSB	0x07
+
+#define ISL29023_NUM_CACHABLE_REGS	8
+#define DEF_RANGE			2
+
+struct isl29023_data {
+	struct i2c_client *client;
+	struct mutex lock;
+	struct input_dev *input;
+	struct work_struct work;
+	struct workqueue_struct *workqueue;
+	char phys[32];
+	u8 reg_cache[ISL29023_NUM_CACHABLE_REGS];
+	u8 mode_before_suspend;
+	u8 mode_before_interrupt;
+	u16 rext;
+};
+
+static int gain_range[] = {
+	1000, 4000, 16000, 64000
+};
+
+/*
+ * register access helpers
+ */
+static int __isl29023_read_reg(struct i2c_client *client,
+			       u32 reg, u8 mask, u8 shift)
+{
+	struct isl29023_data *data = i2c_get_clientdata(client);
+	return (data->reg_cache[reg] & mask) >> shift;
+}
+
+static int __isl29023_write_reg(struct i2c_client *client,
+				u32 reg, u8 mask, u8 shift, u8 val)
+{
+	struct isl29023_data *data = i2c_get_clientdata(client);
+	int ret = 0;
+	u8 tmp;
+
+	if (reg >= ISL29023_NUM_CACHABLE_REGS)
+		return -EINVAL;
+
+	mutex_lock(&data->lock);
+
+	tmp = data->reg_cache[reg];
+	tmp &= ~mask;
+	tmp |= val << shift;
+
+	ret = i2c_smbus_write_byte_data(client, reg, tmp);
+	if (!ret)
+		data->reg_cache[reg] = tmp;
+
+	mutex_unlock(&data->lock);
+	return ret;
+}
+
+/*
+ * internally used functions
+ */
+
+/* interrupt persists */
+static int isl29023_get_int_persists(struct i2c_client *client)
+{
+	return __isl29023_read_reg(client, ISL29023_COMMAND1,
+		ISL29023_INT_PERSISTS_MASK, ISL29023_INT_PERSISTS_SHIFT);
+}
+
+static int isl29023_set_int_persists(struct i2c_client *client,
+				int int_persists)
+{
+	return __isl29023_write_reg(client, ISL29023_COMMAND1,
+		ISL29023_INT_PERSISTS_MASK, ISL29023_INT_PERSISTS_SHIFT,
+		int_persists);
+}
+
+/* interrupt flag */
+static int isl29023_get_int_flag(struct i2c_client *client)
+{
+	return __isl29023_read_reg(client, ISL29023_COMMAND1,
+		ISL29023_INT_FLAG_MASK, ISL29023_INT_FLAG_SHIFT);
+}
+
+static int isl29023_set_int_flag(struct i2c_client *client, int flag)
+{
+	return __isl29023_write_reg(client, ISL29023_COMMAND1,
+		ISL29023_INT_FLAG_MASK, ISL29023_INT_FLAG_SHIFT, flag);
+}
+
+/* interrupt lt */
+static int isl29023_get_int_lt(struct i2c_client *client)
+{
+	struct isl29023_data *data = i2c_get_clientdata(client);
+	int lsb, msb, lt;
+
+	mutex_lock(&data->lock);
+	lsb = i2c_smbus_read_byte_data(client, ISL29023_REG_IRQ_TH_LO_LSB);
+
+	if (lsb < 0) {
+		mutex_unlock(&data->lock);
+		return lsb;
+	}
+
+	msb = i2c_smbus_read_byte_data(client, ISL29023_REG_IRQ_TH_LO_MSB);
+	mutex_unlock(&data->lock);
+
+	if (msb < 0)
+		return msb;
+
+	lt = ((msb << 8) | lsb);
+
+	return lt;
+}
+
+static int isl29023_set_int_lt(struct i2c_client *client, int lt)
+{
+	int ret = 0;
+	struct isl29023_data *data = i2c_get_clientdata(client);
+
+	mutex_lock(&data->lock);
+	ret = i2c_smbus_write_byte_data(client, ISL29023_REG_IRQ_TH_LO_LSB,
+					lt & 0xff);
+	if (ret < 0) {
+		mutex_unlock(&data->lock);
+		return ret;
+	}
+
+	ret = i2c_smbus_write_byte_data(client, ISL29023_REG_IRQ_TH_LO_MSB,
+					(lt >> 8) & 0xff);
+	if (ret < 0) {
+		mutex_unlock(&data->lock);
+		return ret;
+	}
+
+	data->reg_cache[ISL29023_REG_IRQ_TH_LO_MSB] = (lt >> 8) & 0xff;
+	data->reg_cache[ISL29023_REG_IRQ_TH_LO_LSB] = lt & 0xff;
+	mutex_unlock(&data->lock);
+
+	return ret;
+}
+
+/* interrupt ht */
+static int isl29023_get_int_ht(struct i2c_client *client)
+{
+	struct isl29023_data *data = i2c_get_clientdata(client);
+	int lsb, msb, ht;
+
+	mutex_lock(&data->lock);
+	lsb = i2c_smbus_read_byte_data(client, ISL29023_REG_IRQ_TH_HI_LSB);
+
+	if (lsb < 0) {
+		mutex_unlock(&data->lock);
+		return lsb;
+	}
+
+	msb = i2c_smbus_read_byte_data(client, ISL29023_REG_IRQ_TH_HI_MSB);
+	mutex_unlock(&data->lock);
+
+	if (msb < 0)
+		return msb;
+
+	ht = ((msb << 8) | lsb);
+
+	return ht;
+}
+
+static int isl29023_set_int_ht(struct i2c_client *client, int ht)
+{
+	int ret = 0;
+	struct isl29023_data *data = i2c_get_clientdata(client);
+
+	mutex_lock(&data->lock);
+	ret = i2c_smbus_write_byte_data(client, ISL29023_REG_IRQ_TH_HI_LSB,
+					ht & 0xff);
+	if (ret < 0) {
+		mutex_unlock(&data->lock);
+		return ret;
+	}
+
+	ret = i2c_smbus_write_byte_data(client, ISL29023_REG_IRQ_TH_HI_MSB,
+					(ht >> 8) & 0xff);
+	if (ret < 0) {
+		mutex_unlock(&data->lock);
+		return ret;
+	}
+
+	data->reg_cache[ISL29023_REG_IRQ_TH_HI_MSB] = (ht >> 8) & 0xff;
+	data->reg_cache[ISL29023_REG_IRQ_TH_HI_LSB] = ht & 0xff;
+	mutex_unlock(&data->lock);
+
+	return ret;
+}
+
+/* range */
+static int isl29023_get_range(struct i2c_client *client)
+{
+	return __isl29023_read_reg(client, ISL29023_COMMAND2,
+		ISL29023_RANGE_MASK, ISL29023_RANGE_SHIFT);
+}
+
+static int isl29023_set_range(struct i2c_client *client, int range)
+{
+	return __isl29023_write_reg(client, ISL29023_COMMAND2,
+		ISL29023_RANGE_MASK, ISL29023_RANGE_SHIFT, range);
+}
+
+/* resolution */
+static int isl29023_get_resolution(struct i2c_client *client)
+{
+	return __isl29023_read_reg(client, ISL29023_COMMAND2,
+		ISL29023_RES_MASK, ISL29023_RES_SHIFT);
+}
+
+static int isl29023_set_resolution(struct i2c_client *client, int res)
+{
+	return __isl29023_write_reg(client, ISL29023_COMMAND2,
+		ISL29023_RES_MASK, ISL29023_RES_SHIFT, res);
+}
+
+/* mode */
+static int isl29023_get_mode(struct i2c_client *client)
+{
+	return __isl29023_read_reg(client, ISL29023_COMMAND1,
+		ISL29023_MODE_MASK, ISL29023_MODE_SHIFT);
+}
+
+static int isl29023_set_mode(struct i2c_client *client, int mode)
+{
+	return __isl29023_write_reg(client, ISL29023_COMMAND1,
+		ISL29023_MODE_MASK, ISL29023_MODE_SHIFT, mode);
+}
+
+/* power_state */
+static int isl29023_set_power_state(struct i2c_client *client, int state)
+{
+	return __isl29023_write_reg(client, ISL29023_COMMAND1,
+				ISL29023_MODE_MASK, ISL29023_MODE_SHIFT,
+				state ?
+				ISL29023_ALS_ONCE_MODE : ISL29023_PD_MODE);
+}
+
+static int isl29023_get_power_state(struct i2c_client *client)
+{
+	struct isl29023_data *data = i2c_get_clientdata(client);
+	u8 cmdreg = data->reg_cache[ISL29023_COMMAND1];
+
+	if (cmdreg & ISL29023_MODE_MASK)
+		return 1;
+	else
+		return 0;
+}
+
+static int isl29023_get_adc_value(struct i2c_client *client)
+{
+	struct isl29023_data *data = i2c_get_clientdata(client);
+	int lsb, msb, range, bitdepth;
+
+	mutex_lock(&data->lock);
+	lsb = i2c_smbus_read_byte_data(client, ISL29023_REG_LSB_SENSOR);
+
+	if (lsb < 0) {
+		mutex_unlock(&data->lock);
+		return lsb;
+	}
+
+	msb = i2c_smbus_read_byte_data(client, ISL29023_REG_MSB_SENSOR);
+	mutex_unlock(&data->lock);
+
+	if (msb < 0)
+		return msb;
+
+	range = isl29023_get_range(client);
+	bitdepth = (4 - isl29023_get_resolution(client)) * 4;
+	return (((msb << 8) | lsb) * ((gain_range[range] * 499) / data->rext))
+		>> bitdepth;
+}
+
+static int isl29023_get_int_lt_value(struct i2c_client *client)
+{
+	struct isl29023_data *data = i2c_get_clientdata(client);
+	int lsb, msb, range, bitdepth;
+
+	mutex_lock(&data->lock);
+	lsb = i2c_smbus_read_byte_data(client, ISL29023_REG_IRQ_TH_LO_LSB);
+
+	if (lsb < 0) {
+		mutex_unlock(&data->lock);
+		return lsb;
+	}
+
+	msb = i2c_smbus_read_byte_data(client, ISL29023_REG_IRQ_TH_LO_MSB);
+	mutex_unlock(&data->lock);
+
+	if (msb < 0)
+		return msb;
+
+	range = isl29023_get_range(client);
+	bitdepth = (4 - isl29023_get_resolution(client)) * 4;
+	return (((msb << 8) | lsb) * ((gain_range[range] * 499) / data->rext))
+		>> bitdepth;
+}
+
+static int isl29023_get_int_ht_value(struct i2c_client *client)
+{
+	struct isl29023_data *data = i2c_get_clientdata(client);
+	int lsb, msb, range, bitdepth;
+
+	mutex_lock(&data->lock);
+	lsb = i2c_smbus_read_byte_data(client, ISL29023_REG_IRQ_TH_HI_LSB);
+
+	if (lsb < 0) {
+		mutex_unlock(&data->lock);
+		return lsb;
+	}
+
+	msb = i2c_smbus_read_byte_data(client, ISL29023_REG_IRQ_TH_HI_MSB);
+	mutex_unlock(&data->lock);
+
+	if (msb < 0)
+		return msb;
+
+	range = isl29023_get_range(client);
+	bitdepth = (4 - isl29023_get_resolution(client)) * 4;
+	return (((msb << 8) | lsb) * ((gain_range[range] * 499) / data->rext))
+		>> bitdepth;
+}
+
+/*
+ * sysfs layer
+ */
+
+/* interrupt persists */
+static ssize_t isl29023_show_int_persists(struct device *dev,
+					  struct device_attribute *attr,
+					  char *buf)
+{
+	struct i2c_client *client = to_i2c_client(dev);
+	return sprintf(buf, "%i\n", isl29023_get_int_persists(client));
+}
+
+static ssize_t isl29023_store_int_persists(struct device *dev,
+					   struct device_attribute *attr,
+					   const char *buf, size_t count)
+{
+	struct i2c_client *client = to_i2c_client(dev);
+	unsigned long val;
+	int ret;
+
+	if ((strict_strtoul(buf, 10, &val) < 0) ||
+	    (val > ISL29023_INT_PERSISTS_16))
+		return -EINVAL;
+
+	ret = isl29023_set_int_persists(client, val);
+	if (ret < 0)
+		return ret;
+
+	return count;
+}
+
+static DEVICE_ATTR(int_persists, S_IWUSR | S_IRUGO,
+		   isl29023_show_int_persists, isl29023_store_int_persists);
+
+/* interrupt flag */
+static ssize_t isl29023_show_int_flag(struct device *dev,
+					  struct device_attribute *attr,
+					  char *buf)
+{
+	struct i2c_client *client = to_i2c_client(dev);
+	return sprintf(buf, "%i\n", isl29023_get_int_flag(client));
+}
+
+static ssize_t isl29023_store_int_flag(struct device *dev,
+					   struct device_attribute *attr,
+					   const char *buf, size_t count)
+{
+	struct i2c_client *client = to_i2c_client(dev);
+	unsigned long val;
+	int ret;
+
+	if ((strict_strtoul(buf, 10, &val) < 0) || (val > 1))
+		return -EINVAL;
+
+	ret = isl29023_set_int_flag(client, val);
+	if (ret < 0)
+		return ret;
+
+	return count;
+}
+
+static DEVICE_ATTR(int_flag, S_IWUSR | S_IRUGO,
+		   isl29023_show_int_flag, isl29023_store_int_flag);
+
+/* interrupt lt */
+static ssize_t isl29023_show_int_lt(struct device *dev,
+				   struct device_attribute *attr, char *buf)
+{
+	struct i2c_client *client = to_i2c_client(dev);
+	return sprintf(buf, "%i\n", isl29023_get_int_lt(client));
+}
+
+static ssize_t isl29023_store_int_lt(struct device *dev,
+				    struct device_attribute *attr,
+				    const char *buf, size_t count)
+{
+	struct i2c_client *client = to_i2c_client(dev);
+	unsigned long val;
+	int ret;
+
+	if ((strict_strtoul(buf, 16, &val) < 0) || (val > 0xffff))
+		return -EINVAL;
+
+	ret = isl29023_set_int_lt(client, val);
+	if (ret < 0)
+		return ret;
+
+	return count;
+}
+
+static DEVICE_ATTR(int_lt, S_IWUSR | S_IRUGO,
+		   isl29023_show_int_lt, isl29023_store_int_lt);
+
+/* interrupt ht */
+static ssize_t isl29023_show_int_ht(struct device *dev,
+				   struct device_attribute *attr, char *buf)
+{
+	struct i2c_client *client = to_i2c_client(dev);
+	return sprintf(buf, "%i\n", isl29023_get_int_ht(client));
+}
+
+static ssize_t isl29023_store_int_ht(struct device *dev,
+				    struct device_attribute *attr,
+				    const char *buf, size_t count)
+{
+	struct i2c_client *client = to_i2c_client(dev);
+	unsigned long val;
+	int ret;
+
+	if ((strict_strtoul(buf, 16, &val) < 0) || (val > 0xffff))
+		return -EINVAL;
+
+	ret = isl29023_set_int_ht(client, val);
+	if (ret < 0)
+		return ret;
+
+	return count;
+}
+
+static DEVICE_ATTR(int_ht, S_IWUSR | S_IRUGO,
+		   isl29023_show_int_ht, isl29023_store_int_ht);
+
+/* range */
+static ssize_t isl29023_show_range(struct device *dev,
+				   struct device_attribute *attr, char *buf)
+{
+	struct i2c_client *client = to_i2c_client(dev);
+	return sprintf(buf, "%i\n", isl29023_get_range(client));
+}
+
+static ssize_t isl29023_store_range(struct device *dev,
+				    struct device_attribute *attr,
+				    const char *buf, size_t count)
+{
+	struct i2c_client *client = to_i2c_client(dev);
+	unsigned long val;
+	int ret;
+
+	if ((strict_strtoul(buf, 10, &val) < 0) || (val > ISL29023_RANGE_64K))
+		return -EINVAL;
+
+	ret = isl29023_set_range(client, val);
+	if (ret < 0)
+		return ret;
+
+	return count;
+}
+
+static DEVICE_ATTR(range, S_IWUSR | S_IRUGO,
+		   isl29023_show_range, isl29023_store_range);
+
+
+/* resolution */
+static ssize_t isl29023_show_resolution(struct device *dev,
+					struct device_attribute *attr,
+					char *buf)
+{
+	struct i2c_client *client = to_i2c_client(dev);
+	return sprintf(buf, "%d\n", isl29023_get_resolution(client));
+}
+
+static ssize_t isl29023_store_resolution(struct device *dev,
+					 struct device_attribute *attr,
+					 const char *buf, size_t count)
+{
+	struct i2c_client *client = to_i2c_client(dev);
+	unsigned long val;
+	int ret;
+
+	if ((strict_strtoul(buf, 10, &val) < 0) || (val > ISL29023_RES_4))
+		return -EINVAL;
+
+	ret = isl29023_set_resolution(client, val);
+	if (ret < 0)
+		return ret;
+
+	return count;
+}
+
+static DEVICE_ATTR(resolution, S_IWUSR | S_IRUGO,
+		   isl29023_show_resolution, isl29023_store_resolution);
+
+/* mode */
+static ssize_t isl29023_show_mode(struct device *dev,
+				  struct device_attribute *attr, char *buf)
+{
+	struct i2c_client *client = to_i2c_client(dev);
+	return sprintf(buf, "%d\n", isl29023_get_mode(client));
+}
+
+static ssize_t isl29023_store_mode(struct device *dev,
+		struct device_attribute *attr, const char *buf, size_t count)
+{
+	struct i2c_client *client = to_i2c_client(dev);
+	unsigned long val;
+	int ret;
+
+	if ((strict_strtoul(buf, 10, &val) < 0) ||
+	    (val > ISL29023_IR_CONT_MODE))
+		return -EINVAL;
+
+	ret = isl29023_set_mode(client, val);
+	if (ret < 0)
+		return ret;
+
+	return count;
+}
+
+static DEVICE_ATTR(mode, S_IWUSR | S_IRUGO,
+		   isl29023_show_mode, isl29023_store_mode);
+
+
+/* power state */
+static ssize_t isl29023_show_power_state(struct device *dev,
+					 struct device_attribute *attr,
+					 char *buf)
+{
+	struct i2c_client *client = to_i2c_client(dev);
+	return sprintf(buf, "%d\n", isl29023_get_power_state(client));
+}
+
+static ssize_t isl29023_store_power_state(struct device *dev,
+					  struct device_attribute *attr,
+					  const char *buf, size_t count)
+{
+	struct i2c_client *client = to_i2c_client(dev);
+	unsigned long val;
+	int ret;
+
+	if ((strict_strtoul(buf, 10, &val) < 0) || (val > 1))
+		return -EINVAL;
+
+	ret = isl29023_set_power_state(client, val);
+	return ret ? ret : count;
+}
+
+static DEVICE_ATTR(power_state, S_IWUSR | S_IRUGO,
+		   isl29023_show_power_state, isl29023_store_power_state);
+
+/* lux */
+static ssize_t isl29023_show_lux(struct device *dev,
+				 struct device_attribute *attr, char *buf)
+{
+	struct i2c_client *client = to_i2c_client(dev);
+
+	/* No LUX data if not operational */
+	if (!isl29023_get_power_state(client))
+		return -EBUSY;
+
+	return sprintf(buf, "%d\n", isl29023_get_adc_value(client));
+}
+
+static DEVICE_ATTR(lux, S_IRUGO, isl29023_show_lux, NULL);
+
+/* lux interrupt low threshold */
+static ssize_t isl29023_show_int_lt_lux(struct device *dev,
+				 struct device_attribute *attr, char *buf)
+{
+	struct i2c_client *client = to_i2c_client(dev);
+
+	/* No LUX data if not operational */
+	if (isl29023_get_mode(client) != ISL29023_ALS_ONCE_MODE &&
+	    isl29023_get_mode(client) != ISL29023_ALS_CONT_MODE)
+		return -EIO;
+
+	return sprintf(buf, "%d\n", isl29023_get_int_lt_value(client));
+}
+
+static ssize_t isl29023_store_int_lt_lux(struct device *dev,
+		struct device_attribute *attr, const char *buf, size_t count)
+{
+	struct i2c_client *client = to_i2c_client(dev);
+	struct isl29023_data *data = i2c_get_clientdata(client);
+	unsigned long val, lux_data;
+	int range, bitdepth, ret;
+	u8 lsb, msb;
+
+	if ((strict_strtoul(buf, 10, &val) < 0))
+		return -EINVAL;
+
+	/* No LUX data if not operational */
+	if (isl29023_get_mode(client) != ISL29023_ALS_ONCE_MODE &&
+	    isl29023_get_mode(client) != ISL29023_ALS_CONT_MODE)
+		return -EIO;
+
+	if (val > (gain_range[isl29023_get_range(client)]*499/data->rext))
+		return -EINVAL;
+
+	range = isl29023_get_range(client);
+	bitdepth = (4 - isl29023_get_resolution(client)) * 4;
+	lux_data = ((unsigned long)(val << bitdepth)) /
+		((gain_range[range] * 499) / data->rext);
+	lux_data &= 0xffff;
+
+	msb = lux_data >> 8;
+	lsb = lux_data & 0xff;
+
+	mutex_lock(&data->lock);
+	ret = i2c_smbus_write_byte_data(client, ISL29023_REG_IRQ_TH_LO_LSB,
+					lsb);
+	if (ret < 0) {
+		mutex_unlock(&data->lock);
+		return ret;
+	}
+
+	ret = i2c_smbus_write_byte_data(client, ISL29023_REG_IRQ_TH_LO_MSB,
+					msb);
+	if (ret < 0) {
+		mutex_unlock(&data->lock);
+		return ret;
+	}
+
+	data->reg_cache[ISL29023_REG_IRQ_TH_LO_MSB] = msb;
+	data->reg_cache[ISL29023_REG_IRQ_TH_LO_LSB] = lsb;
+	mutex_unlock(&data->lock);
+
+	return count;
+}
+
+static DEVICE_ATTR(int_lt_lux, S_IWUSR | S_IRUGO,
+		isl29023_show_int_lt_lux, isl29023_store_int_lt_lux);
+
+/* lux interrupt high threshold */
+static ssize_t isl29023_show_int_ht_lux(struct device *dev,
+				 struct device_attribute *attr, char *buf)
+{
+	struct i2c_client *client = to_i2c_client(dev);
+
+	/* No LUX data if not operational */
+	if (isl29023_get_mode(client) != ISL29023_ALS_ONCE_MODE &&
+	    isl29023_get_mode(client) != ISL29023_ALS_CONT_MODE)
+		return -EIO;
+
+	return sprintf(buf, "%d\n", isl29023_get_int_ht_value(client));
+}
+
+static ssize_t isl29023_store_int_ht_lux(struct device *dev,
+		struct device_attribute *attr, const char *buf, size_t count)
+{
+	struct i2c_client *client = to_i2c_client(dev);
+	struct isl29023_data *data = i2c_get_clientdata(client);
+	unsigned long val, lux_data;
+	int range, bitdepth, ret;
+	u8 lsb, msb;
+
+	if ((strict_strtoul(buf, 10, &val) < 0))
+		return -EINVAL;
+
+	/* No LUX data if not operational */
+	if (isl29023_get_mode(client) != ISL29023_ALS_ONCE_MODE &&
+	    isl29023_get_mode(client) != ISL29023_ALS_CONT_MODE)
+		return -EIO;
+
+	if (val > (gain_range[isl29023_get_range(client)]*499/data->rext))
+		return -EINVAL;
+
+	range = isl29023_get_range(client);
+	bitdepth = (4 - isl29023_get_resolution(client)) * 4;
+	lux_data = ((unsigned long)(val << bitdepth)) /
+		((gain_range[range] * 499) / data->rext);
+	lux_data &= 0xffff;
+
+	msb = lux_data >> 8;
+	lsb = lux_data & 0xff;
+
+	mutex_lock(&data->lock);
+	ret = i2c_smbus_write_byte_data(client, ISL29023_REG_IRQ_TH_HI_LSB,
+					lsb);
+	if (ret < 0) {
+		mutex_unlock(&data->lock);
+		return ret;
+	}
+
+	ret = i2c_smbus_write_byte_data(client, ISL29023_REG_IRQ_TH_HI_MSB,
+					msb);
+	if (ret < 0) {
+		mutex_unlock(&data->lock);
+		return ret;
+	}
+
+	data->reg_cache[ISL29023_REG_IRQ_TH_HI_MSB] = msb;
+	data->reg_cache[ISL29023_REG_IRQ_TH_HI_LSB] = lsb;
+	mutex_unlock(&data->lock);
+
+	return count;
+}
+
+static DEVICE_ATTR(int_ht_lux, S_IWUSR | S_IRUGO,
+		isl29023_show_int_ht_lux, isl29023_store_int_ht_lux);
+
+static struct attribute *isl29023_attributes[] = {
+	&dev_attr_int_persists.attr,
+	&dev_attr_range.attr,
+	&dev_attr_resolution.attr,
+	&dev_attr_mode.attr,
+	&dev_attr_power_state.attr,
+	&dev_attr_lux.attr,
+	&dev_attr_int_lt_lux.attr,
+	&dev_attr_int_ht_lux.attr,
+	&dev_attr_int_lt.attr,
+	&dev_attr_int_ht.attr,
+	&dev_attr_int_flag.attr,
+	NULL
+};
+
+static const struct attribute_group isl29023_attr_group = {
+	.attrs = isl29023_attributes,
+};
+
+static int isl29023_init_client(struct i2c_client *client)
+{
+	struct isl29023_data *data = i2c_get_clientdata(client);
+	int i;
+
+	/* read all the registers once to fill the cache.
+	 * if one of the reads fails, we consider the init failed */
+	for (i = 0; i < ARRAY_SIZE(data->reg_cache); i++) {
+		int v = i2c_smbus_read_byte_data(client, i);
+		if (v < 0)
+			return -ENODEV;
+
+		data->reg_cache[i] = v;
+	}
+
+	/* set defaults */
+	isl29023_set_int_persists(client, ISL29023_INT_PERSISTS_8);
+	isl29023_set_int_ht(client, 0xffff);
+	isl29023_set_int_lt(client, 0x0);
+	isl29023_set_range(client, ISL29023_RANGE_16K);
+	isl29023_set_resolution(client, ISL29023_RES_16);
+	isl29023_set_mode(client, ISL29023_ALS_ONCE_MODE);
+	isl29023_set_int_flag(client, 0);
+	isl29023_set_power_state(client, 0);
+
+	return 0;
+}
+
+static void isl29023_work(struct work_struct *work)
+{
+	struct isl29023_data *data =
+			container_of(work, struct isl29023_data, work);
+	struct i2c_client *client = data->client;
+	int lux;
+
+	/* Clear interrupt flag */
+	isl29023_set_int_flag(client, 0);
+
+	/*
+	 * Max threshold to avoid multiple interrupts.
+	 * Let the user to reprogramme the interrupt
+	 * thresholds.
+	 */
+	isl29023_set_int_ht(client, 0xffff);
+	isl29023_set_int_lt(client, 0x0);
+
+	data->mode_before_interrupt = isl29023_get_mode(client);
+	lux = isl29023_get_adc_value(client);
+
+	/* To clear the interrpt status */
+	isl29023_set_power_state(client, ISL29023_PD_MODE);
+	isl29023_set_mode(client, data->mode_before_interrupt);
+
+	msleep(100);
+
+	input_report_abs(data->input, ABS_MISC, lux);
+	input_sync(data->input);
+}
+
+static irqreturn_t isl29023_irq_handler(int irq, void *handle)
+{
+	struct isl29023_data *data = handle;
+	queue_work(data->workqueue, &data->work);
+	return IRQ_HANDLED;
+}
+
+/*
+ * I2C layer
+ */
+
+static int __devinit isl29023_probe(struct i2c_client *client,
+				    const struct i2c_device_id *id)
+{
+	struct i2c_adapter *adapter = to_i2c_adapter(client->dev.parent);
+	struct isl29023_data *data;
+	struct mxc_lightsensor_platform_data *ls_data;
+	struct input_dev *input_dev;
+	int err = 0;
+
+	if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE))
+		return -EIO;
+
+	data = kzalloc(sizeof(struct isl29023_data), GFP_KERNEL);
+	if (!data)
+		return -ENOMEM;
+
+	ls_data = (struct mxc_lightsensor_platform_data *)
+	    (client->dev).platform_data;
+
+	data->client = client;
+	data->rext = ls_data->rext;
+	snprintf(data->phys, sizeof(data->phys),
+		 "%s", dev_name(&client->dev));
+	i2c_set_clientdata(client, data);
+	mutex_init(&data->lock);
+
+	/* initialize the ISL29023 chip */
+	err = isl29023_init_client(client);
+	if (err)
+		goto exit_kfree;
+
+	/* register sysfs hooks */
+	err = sysfs_create_group(&client->dev.kobj, &isl29023_attr_group);
+	if (err)
+		goto exit_kfree;
+
+	input_dev = input_allocate_device();
+	if (!input_dev) {
+		err = -ENOMEM;
+		goto exit_kfree;
+	}
+
+	data->input = input_dev;
+	input_dev->name = "isl29023 light sensor";
+	input_dev->id.bustype = BUS_I2C;
+	input_dev->phys = data->phys;
+
+	__set_bit(EV_ABS, input_dev->evbit);
+	input_set_abs_params(input_dev, ABS_MISC, 0,
+			gain_range[DEF_RANGE]*499/data->rext, 0, 0);
+
+	err = input_register_device(input_dev);
+	if (err)
+		goto exit_free_input;
+
+	/* set irq type to edge falling */
+	set_irq_type(client->irq, IRQF_TRIGGER_FALLING);
+	err = request_irq(client->irq, isl29023_irq_handler, 0,
+			  client->dev.driver->name, data);
+	if (err < 0) {
+		dev_err(&client->dev, "failed to register irq %d!\n",
+			client->irq);
+		goto exit_free_input;
+	}
+
+	data->workqueue = create_singlethread_workqueue("isl29023");
+	INIT_WORK(&data->work, isl29023_work);
+	if (data->workqueue == NULL) {
+		dev_err(&client->dev, "couldn't create workqueue\n");
+		err = -ENOMEM;
+		goto exit_free_interrupt;
+	}
+
+	dev_info(&client->dev, "driver version %s enabled\n", DRIVER_VERSION);
+	return 0;
+
+exit_free_interrupt:
+	free_irq(client->irq, data);
+exit_free_input:
+	input_free_device(input_dev);
+exit_kfree:
+	kfree(data);
+	return err;
+}
+
+static int __devexit isl29023_remove(struct i2c_client *client)
+{
+	struct isl29023_data *data = i2c_get_clientdata(client);
+
+	cancel_work_sync(&data->work);
+	destroy_workqueue(data->workqueue);
+	free_irq(client->irq, data);
+	input_unregister_device(data->input);
+	input_free_device(data->input);
+	sysfs_remove_group(&client->dev.kobj, &isl29023_attr_group);
+	isl29023_set_power_state(client, 0);
+	kfree(i2c_get_clientdata(client));
+
+	return 0;
+}
+
+#ifdef CONFIG_PM
+static int isl29023_suspend(struct i2c_client *client, pm_message_t mesg)
+{
+	struct isl29023_data *data = i2c_get_clientdata(client);
+
+	data->mode_before_suspend = isl29023_get_mode(client);
+	return isl29023_set_power_state(client, ISL29023_PD_MODE);
+}
+
+static int isl29023_resume(struct i2c_client *client)
+{
+	int i;
+	struct isl29023_data *data = i2c_get_clientdata(client);
+
+	/* restore registers from cache */
+	for (i = 0; i < ARRAY_SIZE(data->reg_cache); i++)
+		if (i2c_smbus_write_byte_data(client, i, data->reg_cache[i]))
+			return -EIO;
+
+	return isl29023_set_mode(client, data->mode_before_suspend);
+}
+
+#else
+#define isl29023_suspend	NULL
+#define isl29023_resume		NULL
+#endif /* CONFIG_PM */
+
+static const struct i2c_device_id isl29023_id[] = {
+	{ ISL29023_DRV_NAME, 0 },
+	{}
+};
+MODULE_DEVICE_TABLE(i2c, isl29023_id);
+
+static struct i2c_driver isl29023_driver = {
+	.driver = {
+		.name	= ISL29023_DRV_NAME,
+		.owner	= THIS_MODULE,
+	},
+	.suspend = isl29023_suspend,
+	.resume	= isl29023_resume,
+	.probe	= isl29023_probe,
+	.remove	= __devexit_p(isl29023_remove),
+	.id_table = isl29023_id,
+};
+
+static int __init isl29023_init(void)
+{
+	return i2c_add_driver(&isl29023_driver);
+}
+
+static void __exit isl29023_exit(void)
+{
+	i2c_del_driver(&isl29023_driver);
+}
+
+MODULE_AUTHOR("Freescale Semiconductor, Inc.");
+MODULE_DESCRIPTION("ISL29023 ambient light sensor driver");
+MODULE_LICENSE("GPL");
+MODULE_VERSION(DRIVER_VERSION);
+
+module_init(isl29023_init);
+module_exit(isl29023_exit);