iio: add LM3533 ambient-light-sensor driver
authorJohan Hovold <jhovold@gmail.com>
Mon, 21 May 2012 12:18:06 +0000 (14:18 +0200)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Tue, 5 Jun 2012 04:12:29 +0000 (21:12 -0700)
Add sub-driver for the ambient-light-sensor interface on National
Semiconductor / TI LM3533 lighting power chips.

The sensor interface can be used to control the LEDs and backlights of
the chip through defining five light zones and three sets of
corresponding output-current values.

The driver provides raw and mean adc readings along with the current
light zone through sysfs. A threshold event can be generated on zone
changes. The ALS-control output values can be set per zone for the three
current output channels.

Signed-off-by: Johan Hovold <jhovold@gmail.com>
Acked-by: Jonathan Cameron <jic23@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Documentation/ABI/testing/sysfs-bus-iio-light-lm3533-als [new file with mode: 0644]
drivers/iio/Kconfig
drivers/iio/Makefile
drivers/iio/light/Kconfig [new file with mode: 0644]
drivers/iio/light/Makefile [new file with mode: 0644]
drivers/iio/light/lm3533-als.c [new file with mode: 0644]

diff --git a/Documentation/ABI/testing/sysfs-bus-iio-light-lm3533-als b/Documentation/ABI/testing/sysfs-bus-iio-light-lm3533-als
new file mode 100644 (file)
index 0000000..694a52c
--- /dev/null
@@ -0,0 +1,62 @@
+What:          /sys/.../events/in_illuminance0_thresh_either_en
+Date:          April 2012
+KernelVersion: 3.5
+Contact:       Johan Hovold <jhovold@gmail.com>
+Description:
+               Event generated when channel passes one of the four thresholds
+               in each direction (rising|falling) and a zone change occurs.
+               The corresponding light zone can be read from
+               in_illuminance0_zone.
+
+What:          /sys/.../events/in_illuminance0_threshY_hysteresis
+Date:          May 2012
+KernelVersion: 3.5
+Contact:       Johan Hovold <jhovold@gmail.com>
+Description:
+               Get the hysteresis for thresholds Y, that is,
+
+               threshY_hysteresis = threshY_raising - threshY_falling
+
+What:          /sys/.../events/illuminance_threshY_falling_value
+What:          /sys/.../events/illuminance_threshY_raising_value
+Date:          April 2012
+KernelVersion: 3.5
+Contact:       Johan Hovold <jhovold@gmail.com>
+Description:
+               Specifies the value of threshold that the device is comparing
+               against for the events enabled by
+               in_illuminance0_thresh_either_en (0..255), where Y in 0..3.
+
+               Note that threshY_falling must be less than or equal to
+               threshY_raising.
+
+               These thresholds correspond to the eight zone-boundary
+               registers (boundaryY_{low,high}) and defines the five light
+               zones.
+
+What:          /sys/bus/iio/devices/iio:deviceX/in_illuminance0_zone
+Date:          April 2012
+KernelVersion: 3.5
+Contact:       Johan Hovold <jhovold@gmail.com>
+Description:
+               Get the current light zone (0..4) as defined by the
+               in_illuminance0_threshY_{falling,rising} thresholds.
+
+What:          /sys/bus/iio/devices/iio:deviceX/out_currentY_raw
+Date:          May 2012
+KernelVersion: 3.5
+Contact:       Johan Hovold <jhovold@gmail.com>
+Description:
+               Get output current for channel Y (0..255), that is,
+               out_currentY_currentZ_raw, where Z is the current zone.
+
+What:          /sys/bus/iio/devices/iio:deviceX/out_currentY_currentZ_raw
+Date:          May 2012
+KernelVersion: 3.5
+Contact:       Johan Hovold <jhovold@gmail.com>
+Description:
+               Set the output current for channel out_currentY when in zone
+               Z (0..255), where Y in 0..2 and Z in 0..4.
+
+               These values correspond to the ALS-mapper target registers for
+               ALS-mapper Y + 1.
index 56eecef..cacc74d 100644 (file)
@@ -50,5 +50,6 @@ config IIO_CONSUMERS_PER_TRIGGER
 
 source "drivers/iio/adc/Kconfig"
 source "drivers/iio/amplifiers/Kconfig"
+source "drivers/iio/light/Kconfig"
 
 endif # IIO
index e425afd..060b674 100644 (file)
@@ -11,3 +11,4 @@ obj-$(CONFIG_IIO_KFIFO_BUF) += kfifo_buf.o
 
 obj-y += adc/
 obj-y += amplifiers/
+obj-y += light/
diff --git a/drivers/iio/light/Kconfig b/drivers/iio/light/Kconfig
new file mode 100644 (file)
index 0000000..db5618e
--- /dev/null
@@ -0,0 +1,22 @@
+#
+# Light sensors
+#
+menu "Light sensors"
+
+config SENSORS_LM3533
+       tristate "LM3533 ambient light sensor"
+       depends on MFD_LM3533
+       help
+         If you say yes here you get support for the ambient light sensor
+         interface on National Semiconductor / TI LM3533 Lighting Power
+         chips.
+
+         The sensor interface can be used to control the LEDs and backlights
+         of the chip through defining five light zones and three sets of
+         corresponding output-current values.
+
+         The driver provides raw and mean adc readings along with the current
+         light zone through sysfs. A threshold event can be generated on zone
+         changes. The ALS-control output values can be set per zone for the
+         three current output channels.
+endmenu
diff --git a/drivers/iio/light/Makefile b/drivers/iio/light/Makefile
new file mode 100644 (file)
index 0000000..c1c23a0
--- /dev/null
@@ -0,0 +1,5 @@
+#
+# Makefile for IIO Light sensors
+#
+
+obj-$(CONFIG_SENSORS_LM3533)   += lm3533-als.o
diff --git a/drivers/iio/light/lm3533-als.c b/drivers/iio/light/lm3533-als.c
new file mode 100644 (file)
index 0000000..c3e7bac
--- /dev/null
@@ -0,0 +1,932 @@
+/*
+ * lm3533-als.c -- LM3533 Ambient Light Sensor driver
+ *
+ * Copyright (C) 2011-2012 Texas Instruments
+ *
+ * Author: Johan Hovold <jhovold@gmail.com>
+ *
+ * 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.
+ */
+
+#include <linux/atomic.h>
+#include <linux/fs.h>
+#include <linux/interrupt.h>
+#include <linux/io.h>
+#include <linux/iio/events.h>
+#include <linux/iio/iio.h>
+#include <linux/module.h>
+#include <linux/mutex.h>
+#include <linux/mfd/core.h>
+#include <linux/platform_device.h>
+#include <linux/slab.h>
+#include <linux/uaccess.h>
+
+#include <linux/mfd/lm3533.h>
+
+
+#define LM3533_ALS_RESISTOR_MIN                        1
+#define LM3533_ALS_RESISTOR_MAX                        127
+#define LM3533_ALS_CHANNEL_CURRENT_MAX         2
+#define LM3533_ALS_THRESH_MAX                  3
+#define LM3533_ALS_ZONE_MAX                    4
+
+#define LM3533_REG_ALS_RESISTOR_SELECT         0x30
+#define LM3533_REG_ALS_CONF                    0x31
+#define LM3533_REG_ALS_ZONE_INFO               0x34
+#define LM3533_REG_ALS_READ_ADC_RAW            0x37
+#define LM3533_REG_ALS_READ_ADC_AVERAGE                0x38
+#define LM3533_REG_ALS_BOUNDARY_BASE           0x50
+#define LM3533_REG_ALS_TARGET_BASE             0x60
+
+#define LM3533_ALS_ENABLE_MASK                 0x01
+#define LM3533_ALS_INPUT_MODE_MASK             0x02
+#define LM3533_ALS_INT_ENABLE_MASK             0x01
+
+#define LM3533_ALS_ZONE_SHIFT                  2
+#define LM3533_ALS_ZONE_MASK                   0x1c
+
+#define LM3533_ALS_FLAG_INT_ENABLED            1
+
+
+struct lm3533_als {
+       struct lm3533 *lm3533;
+       struct platform_device *pdev;
+
+       unsigned long flags;
+       int irq;
+
+       atomic_t zone;
+       struct mutex thresh_mutex;
+};
+
+
+static int lm3533_als_get_adc(struct iio_dev *indio_dev, bool average,
+                                                               int *adc)
+{
+       struct lm3533_als *als = iio_priv(indio_dev);
+       u8 reg;
+       u8 val;
+       int ret;
+
+       if (average)
+               reg = LM3533_REG_ALS_READ_ADC_AVERAGE;
+       else
+               reg = LM3533_REG_ALS_READ_ADC_RAW;
+
+       ret = lm3533_read(als->lm3533, reg, &val);
+       if (ret) {
+               dev_err(&indio_dev->dev, "failed to read adc\n");
+               return ret;
+       }
+
+       *adc = val;
+
+       return 0;
+}
+
+static int _lm3533_als_get_zone(struct iio_dev *indio_dev, u8 *zone)
+{
+       struct lm3533_als *als = iio_priv(indio_dev);
+       u8 val;
+       int ret;
+
+       ret = lm3533_read(als->lm3533, LM3533_REG_ALS_ZONE_INFO, &val);
+       if (ret) {
+               dev_err(&indio_dev->dev, "failed to read zone\n");
+               return ret;
+       }
+
+       val = (val & LM3533_ALS_ZONE_MASK) >> LM3533_ALS_ZONE_SHIFT;
+       *zone = min_t(u8, val, LM3533_ALS_ZONE_MAX);
+
+       return 0;
+}
+
+static int lm3533_als_get_zone(struct iio_dev *indio_dev, u8 *zone)
+{
+       struct lm3533_als *als = iio_priv(indio_dev);
+       int ret;
+
+       if (test_bit(LM3533_ALS_FLAG_INT_ENABLED, &als->flags)) {
+               *zone = atomic_read(&als->zone);
+       } else {
+               ret = _lm3533_als_get_zone(indio_dev, zone);
+               if (ret)
+                       return ret;
+       }
+
+       return 0;
+}
+
+/*
+ * channel     output channel 0..2
+ * zone                zone 0..4
+ */
+static inline u8 lm3533_als_get_target_reg(unsigned channel, unsigned zone)
+{
+       return LM3533_REG_ALS_TARGET_BASE + 5 * channel + zone;
+}
+
+static int lm3533_als_get_target(struct iio_dev *indio_dev, unsigned channel,
+                                                       unsigned zone, u8 *val)
+{
+       struct lm3533_als *als = iio_priv(indio_dev);
+       u8 reg;
+       int ret;
+
+       if (channel > LM3533_ALS_CHANNEL_CURRENT_MAX)
+               return -EINVAL;
+
+       if (zone > LM3533_ALS_ZONE_MAX)
+               return -EINVAL;
+
+       reg = lm3533_als_get_target_reg(channel, zone);
+       ret = lm3533_read(als->lm3533, reg, val);
+       if (ret)
+               dev_err(&indio_dev->dev, "failed to get target current\n");
+
+       return ret;
+}
+
+static int lm3533_als_set_target(struct iio_dev *indio_dev, unsigned channel,
+                                                       unsigned zone, u8 val)
+{
+       struct lm3533_als *als = iio_priv(indio_dev);
+       u8 reg;
+       int ret;
+
+       if (channel > LM3533_ALS_CHANNEL_CURRENT_MAX)
+               return -EINVAL;
+
+       if (zone > LM3533_ALS_ZONE_MAX)
+               return -EINVAL;
+
+       reg = lm3533_als_get_target_reg(channel, zone);
+       ret = lm3533_write(als->lm3533, reg, val);
+       if (ret)
+               dev_err(&indio_dev->dev, "failed to set target current\n");
+
+       return ret;
+}
+
+static int lm3533_als_get_current(struct iio_dev *indio_dev, unsigned channel,
+                                                               int *val)
+{
+       u8 zone;
+       u8 target;
+       int ret;
+
+       ret = lm3533_als_get_zone(indio_dev, &zone);
+       if (ret)
+               return ret;
+
+       ret = lm3533_als_get_target(indio_dev, channel, zone, &target);
+       if (ret)
+               return ret;
+
+       *val = target;
+
+       return 0;
+}
+
+static int lm3533_als_read_raw(struct iio_dev *indio_dev,
+                               struct iio_chan_spec const *chan,
+                               int *val, int *val2, long mask)
+{
+       int ret;
+
+       switch (mask) {
+       case 0:
+               switch (chan->type) {
+               case IIO_LIGHT:
+                       ret = lm3533_als_get_adc(indio_dev, false, val);
+                       break;
+               case IIO_CURRENT:
+                       ret = lm3533_als_get_current(indio_dev, chan->channel,
+                                                                       val);
+                       break;
+               default:
+                       return -EINVAL;
+               }
+               break;
+       case IIO_CHAN_INFO_AVERAGE_RAW:
+               ret = lm3533_als_get_adc(indio_dev, true, val);
+               break;
+       default:
+               return -EINVAL;
+       }
+
+       if (ret)
+               return ret;
+
+       return IIO_VAL_INT;
+}
+
+#define CHANNEL_CURRENT(_channel)                                      \
+       {                                                               \
+               .type           = IIO_CURRENT,                          \
+               .channel        = _channel,                             \
+               .indexed        = true,                                 \
+               .output         = true,                                 \
+               .info_mask      = IIO_CHAN_INFO_RAW_SEPARATE_BIT,       \
+       }
+
+static const struct iio_chan_spec lm3533_als_channels[] = {
+       {
+               .type           = IIO_LIGHT,
+               .channel        = 0,
+               .indexed        = true,
+               .info_mask      = (IIO_CHAN_INFO_AVERAGE_RAW_SEPARATE_BIT |
+                                  IIO_CHAN_INFO_RAW_SEPARATE_BIT),
+       },
+       CHANNEL_CURRENT(0),
+       CHANNEL_CURRENT(1),
+       CHANNEL_CURRENT(2),
+};
+
+static irqreturn_t lm3533_als_isr(int irq, void *dev_id)
+{
+
+       struct iio_dev *indio_dev = dev_id;
+       struct lm3533_als *als = iio_priv(indio_dev);
+       u8 zone;
+       int ret;
+
+       /* Clear interrupt by reading the ALS zone register. */
+       ret = _lm3533_als_get_zone(indio_dev, &zone);
+       if (ret)
+               goto out;
+
+       atomic_set(&als->zone, zone);
+
+       iio_push_event(indio_dev,
+                      IIO_UNMOD_EVENT_CODE(IIO_LIGHT,
+                                           0,
+                                           IIO_EV_TYPE_THRESH,
+                                           IIO_EV_DIR_EITHER),
+                      iio_get_time_ns());
+out:
+       return IRQ_HANDLED;
+}
+
+static int lm3533_als_set_int_mode(struct iio_dev *indio_dev, int enable)
+{
+       struct lm3533_als *als = iio_priv(indio_dev);
+       u8 mask = LM3533_ALS_INT_ENABLE_MASK;
+       u8 val;
+       int ret;
+
+       if (enable)
+               val = mask;
+       else
+               val = 0;
+
+       ret = lm3533_update(als->lm3533, LM3533_REG_ALS_ZONE_INFO, val, mask);
+       if (ret) {
+               dev_err(&indio_dev->dev, "failed to set int mode %d\n",
+                                                               enable);
+               return ret;
+       }
+
+       return 0;
+}
+
+static int lm3533_als_get_int_mode(struct iio_dev *indio_dev, int *enable)
+{
+       struct lm3533_als *als = iio_priv(indio_dev);
+       u8 mask = LM3533_ALS_INT_ENABLE_MASK;
+       u8 val;
+       int ret;
+
+       ret = lm3533_read(als->lm3533, LM3533_REG_ALS_ZONE_INFO, &val);
+       if (ret) {
+               dev_err(&indio_dev->dev, "failed to get int mode\n");
+               return ret;
+       }
+
+       *enable = !!(val & mask);
+
+       return 0;
+}
+
+static inline u8 lm3533_als_get_threshold_reg(unsigned nr, bool raising)
+{
+       u8 offset = !raising;
+
+       return LM3533_REG_ALS_BOUNDARY_BASE + 2 * nr + offset;
+}
+
+static int lm3533_als_get_threshold(struct iio_dev *indio_dev, unsigned nr,
+                                                       bool raising, u8 *val)
+{
+       struct lm3533_als *als = iio_priv(indio_dev);
+       u8 reg;
+       int ret;
+
+       if (nr > LM3533_ALS_THRESH_MAX)
+               return -EINVAL;
+
+       reg = lm3533_als_get_threshold_reg(nr, raising);
+       ret = lm3533_read(als->lm3533, reg, val);
+       if (ret)
+               dev_err(&indio_dev->dev, "failed to get threshold\n");
+
+       return ret;
+}
+
+static int lm3533_als_set_threshold(struct iio_dev *indio_dev, unsigned nr,
+                                                       bool raising, u8 val)
+{
+       struct lm3533_als *als = iio_priv(indio_dev);
+       u8 val2;
+       u8 reg, reg2;
+       int ret;
+
+       if (nr > LM3533_ALS_THRESH_MAX)
+               return -EINVAL;
+
+       reg = lm3533_als_get_threshold_reg(nr, raising);
+       reg2 = lm3533_als_get_threshold_reg(nr, !raising);
+
+       mutex_lock(&als->thresh_mutex);
+       ret = lm3533_read(als->lm3533, reg2, &val2);
+       if (ret) {
+               dev_err(&indio_dev->dev, "failed to get threshold\n");
+               goto out;
+       }
+       /*
+        * This device does not allow negative hysteresis (in fact, it uses
+        * whichever value is smaller as the lower bound) so we need to make
+        * sure that thresh_falling <= thresh_raising.
+        */
+       if ((raising && (val < val2)) || (!raising && (val > val2))) {
+               ret = -EINVAL;
+               goto out;
+       }
+
+       ret = lm3533_write(als->lm3533, reg, val);
+       if (ret) {
+               dev_err(&indio_dev->dev, "failed to set threshold\n");
+               goto out;
+       }
+out:
+       mutex_unlock(&als->thresh_mutex);
+
+       return ret;
+}
+
+static int lm3533_als_get_hysteresis(struct iio_dev *indio_dev, unsigned nr,
+                                                               u8 *val)
+{
+       struct lm3533_als *als = iio_priv(indio_dev);
+       u8 falling;
+       u8 raising;
+       int ret;
+
+       if (nr > LM3533_ALS_THRESH_MAX)
+               return -EINVAL;
+
+       mutex_lock(&als->thresh_mutex);
+       ret = lm3533_als_get_threshold(indio_dev, nr, false, &falling);
+       if (ret)
+               goto out;
+       ret = lm3533_als_get_threshold(indio_dev, nr, true, &raising);
+       if (ret)
+               goto out;
+
+       *val = raising - falling;
+out:
+       mutex_unlock(&als->thresh_mutex);
+
+       return ret;
+}
+
+static int show_thresh_either_en(struct device *dev,
+                                       struct device_attribute *attr,
+                                       char *buf)
+{
+       struct iio_dev *indio_dev = dev_to_iio_dev(dev);
+       struct lm3533_als *als = iio_priv(indio_dev);
+       int enable;
+       int ret;
+
+       if (als->irq) {
+               ret = lm3533_als_get_int_mode(indio_dev, &enable);
+               if (ret)
+                       return ret;
+       } else {
+               enable = 0;
+       }
+
+       return scnprintf(buf, PAGE_SIZE, "%u\n", enable);
+}
+
+static int store_thresh_either_en(struct device *dev,
+                                       struct device_attribute *attr,
+                                       const char *buf, size_t len)
+{
+       struct iio_dev *indio_dev = dev_to_iio_dev(dev);
+       struct lm3533_als *als = iio_priv(indio_dev);
+       unsigned long enable;
+       bool int_enabled;
+       u8 zone;
+       int ret;
+
+       if (!als->irq)
+               return -EBUSY;
+
+       if (kstrtoul(buf, 0, &enable))
+               return -EINVAL;
+
+       int_enabled = test_bit(LM3533_ALS_FLAG_INT_ENABLED, &als->flags);
+
+       if (enable && !int_enabled) {
+               ret = lm3533_als_get_zone(indio_dev, &zone);
+               if (ret)
+                       return ret;
+
+               atomic_set(&als->zone, zone);
+
+               set_bit(LM3533_ALS_FLAG_INT_ENABLED, &als->flags);
+       }
+
+       ret = lm3533_als_set_int_mode(indio_dev, enable);
+       if (ret) {
+               if (!int_enabled)
+                       clear_bit(LM3533_ALS_FLAG_INT_ENABLED, &als->flags);
+
+               return ret;
+       }
+
+       if (!enable)
+               clear_bit(LM3533_ALS_FLAG_INT_ENABLED, &als->flags);
+
+       return len;
+}
+
+static ssize_t show_zone(struct device *dev,
+                               struct device_attribute *attr, char *buf)
+{
+       struct iio_dev *indio_dev = dev_to_iio_dev(dev);
+       u8 zone;
+       int ret;
+
+       ret = lm3533_als_get_zone(indio_dev, &zone);
+       if (ret)
+               return ret;
+
+       return scnprintf(buf, PAGE_SIZE, "%u\n", zone);
+}
+
+enum lm3533_als_attribute_type {
+       LM3533_ATTR_TYPE_HYSTERESIS,
+       LM3533_ATTR_TYPE_TARGET,
+       LM3533_ATTR_TYPE_THRESH_FALLING,
+       LM3533_ATTR_TYPE_THRESH_RAISING,
+};
+
+struct lm3533_als_attribute {
+       struct device_attribute dev_attr;
+       enum lm3533_als_attribute_type type;
+       u8 val1;
+       u8 val2;
+};
+
+static inline struct lm3533_als_attribute *
+to_lm3533_als_attr(struct device_attribute *attr)
+{
+       return container_of(attr, struct lm3533_als_attribute, dev_attr);
+}
+
+static ssize_t show_als_attr(struct device *dev,
+                                       struct device_attribute *attr,
+                                       char *buf)
+{
+       struct iio_dev *indio_dev = dev_to_iio_dev(dev);
+       struct lm3533_als_attribute *als_attr = to_lm3533_als_attr(attr);
+       u8 val;
+       int ret;
+
+       switch (als_attr->type) {
+       case LM3533_ATTR_TYPE_HYSTERESIS:
+               ret = lm3533_als_get_hysteresis(indio_dev, als_attr->val1,
+                                                                       &val);
+               break;
+       case LM3533_ATTR_TYPE_TARGET:
+               ret = lm3533_als_get_target(indio_dev, als_attr->val1,
+                                                       als_attr->val2, &val);
+               break;
+       case LM3533_ATTR_TYPE_THRESH_FALLING:
+               ret = lm3533_als_get_threshold(indio_dev, als_attr->val1,
+                                                               false, &val);
+               break;
+       case LM3533_ATTR_TYPE_THRESH_RAISING:
+               ret = lm3533_als_get_threshold(indio_dev, als_attr->val1,
+                                                               true, &val);
+               break;
+       default:
+               ret = -ENXIO;
+       }
+
+       if (ret)
+               return ret;
+
+       return scnprintf(buf, PAGE_SIZE, "%u\n", val);
+}
+
+static ssize_t store_als_attr(struct device *dev,
+                                       struct device_attribute *attr,
+                                       const char *buf, size_t len)
+{
+       struct iio_dev *indio_dev = dev_to_iio_dev(dev);
+       struct lm3533_als_attribute *als_attr = to_lm3533_als_attr(attr);
+       u8 val;
+       int ret;
+
+       if (kstrtou8(buf, 0, &val))
+               return -EINVAL;
+
+       switch (als_attr->type) {
+       case LM3533_ATTR_TYPE_TARGET:
+               ret = lm3533_als_set_target(indio_dev, als_attr->val1,
+                                                       als_attr->val2, val);
+               break;
+       case LM3533_ATTR_TYPE_THRESH_FALLING:
+               ret = lm3533_als_set_threshold(indio_dev, als_attr->val1,
+                                                               false, val);
+               break;
+       case LM3533_ATTR_TYPE_THRESH_RAISING:
+               ret = lm3533_als_set_threshold(indio_dev, als_attr->val1,
+                                                               true, val);
+               break;
+       default:
+               ret = -ENXIO;
+       }
+
+       if (ret)
+               return ret;
+
+       return len;
+}
+
+#define ALS_ATTR(_name, _mode, _show, _store, _type, _val1, _val2)     \
+       { .dev_attr     = __ATTR(_name, _mode, _show, _store),          \
+         .type         = _type,                                        \
+         .val1         = _val1,                                        \
+         .val2         = _val2 }
+
+#define LM3533_ALS_ATTR(_name, _mode, _show, _store, _type, _val1, _val2) \
+       struct lm3533_als_attribute lm3533_als_attr_##_name =             \
+               ALS_ATTR(_name, _mode, _show, _store, _type, _val1, _val2)
+
+#define ALS_TARGET_ATTR_RW(_channel, _zone)                            \
+       LM3533_ALS_ATTR(out_current##_channel##_current##_zone##_raw,   \
+                               S_IRUGO | S_IWUSR,                      \
+                               show_als_attr, store_als_attr,          \
+                               LM3533_ATTR_TYPE_TARGET, _channel, _zone)
+/*
+ * ALS output current values (ALS mapper targets)
+ *
+ * out_current[0-2]_current[0-4]_raw           0-255
+ */
+static ALS_TARGET_ATTR_RW(0, 0);
+static ALS_TARGET_ATTR_RW(0, 1);
+static ALS_TARGET_ATTR_RW(0, 2);
+static ALS_TARGET_ATTR_RW(0, 3);
+static ALS_TARGET_ATTR_RW(0, 4);
+
+static ALS_TARGET_ATTR_RW(1, 0);
+static ALS_TARGET_ATTR_RW(1, 1);
+static ALS_TARGET_ATTR_RW(1, 2);
+static ALS_TARGET_ATTR_RW(1, 3);
+static ALS_TARGET_ATTR_RW(1, 4);
+
+static ALS_TARGET_ATTR_RW(2, 0);
+static ALS_TARGET_ATTR_RW(2, 1);
+static ALS_TARGET_ATTR_RW(2, 2);
+static ALS_TARGET_ATTR_RW(2, 3);
+static ALS_TARGET_ATTR_RW(2, 4);
+
+#define ALS_THRESH_FALLING_ATTR_RW(_nr)                                        \
+       LM3533_ALS_ATTR(in_illuminance0_thresh##_nr##_falling_value,    \
+                       S_IRUGO | S_IWUSR,                              \
+                       show_als_attr, store_als_attr,          \
+                       LM3533_ATTR_TYPE_THRESH_FALLING, _nr, 0)
+
+#define ALS_THRESH_RAISING_ATTR_RW(_nr)                                        \
+       LM3533_ALS_ATTR(in_illuminance0_thresh##_nr##_raising_value,    \
+                       S_IRUGO | S_IWUSR,                              \
+                       show_als_attr, store_als_attr,                  \
+                       LM3533_ATTR_TYPE_THRESH_RAISING, _nr, 0)
+/*
+ * ALS Zone thresholds (boundaries)
+ *
+ * in_illuminance0_thresh[0-3]_falling_value   0-255
+ * in_illuminance0_thresh[0-3]_raising_value   0-255
+ */
+static ALS_THRESH_FALLING_ATTR_RW(0);
+static ALS_THRESH_FALLING_ATTR_RW(1);
+static ALS_THRESH_FALLING_ATTR_RW(2);
+static ALS_THRESH_FALLING_ATTR_RW(3);
+
+static ALS_THRESH_RAISING_ATTR_RW(0);
+static ALS_THRESH_RAISING_ATTR_RW(1);
+static ALS_THRESH_RAISING_ATTR_RW(2);
+static ALS_THRESH_RAISING_ATTR_RW(3);
+
+#define ALS_HYSTERESIS_ATTR_RO(_nr)                                    \
+       LM3533_ALS_ATTR(in_illuminance0_thresh##_nr##_hysteresis,       \
+                       S_IRUGO, show_als_attr, NULL,                   \
+                       LM3533_ATTR_TYPE_HYSTERESIS, _nr, 0)
+/*
+ * ALS Zone threshold hysteresis
+ *
+ * threshY_hysteresis = threshY_raising - threshY_falling
+ *
+ * in_illuminance0_thresh[0-3]_hysteresis      0-255
+ * in_illuminance0_thresh[0-3]_hysteresis      0-255
+ */
+static ALS_HYSTERESIS_ATTR_RO(0);
+static ALS_HYSTERESIS_ATTR_RO(1);
+static ALS_HYSTERESIS_ATTR_RO(2);
+static ALS_HYSTERESIS_ATTR_RO(3);
+
+#define ILLUMINANCE_ATTR_RO(_name) \
+       DEVICE_ATTR(in_illuminance0_##_name, S_IRUGO, show_##_name, NULL)
+#define ILLUMINANCE_ATTR_RW(_name) \
+       DEVICE_ATTR(in_illuminance0_##_name, S_IRUGO | S_IWUSR , \
+                                               show_##_name, store_##_name)
+/*
+ * ALS Zone threshold-event enable
+ *
+ * in_illuminance0_thresh_either_en            0,1
+ */
+static ILLUMINANCE_ATTR_RW(thresh_either_en);
+
+/*
+ * ALS Current Zone
+ *
+ * in_illuminance0_zone                0-4
+ */
+static ILLUMINANCE_ATTR_RO(zone);
+
+static struct attribute *lm3533_als_event_attributes[] = {
+       &dev_attr_in_illuminance0_thresh_either_en.attr,
+       &lm3533_als_attr_in_illuminance0_thresh0_falling_value.dev_attr.attr,
+       &lm3533_als_attr_in_illuminance0_thresh0_hysteresis.dev_attr.attr,
+       &lm3533_als_attr_in_illuminance0_thresh0_raising_value.dev_attr.attr,
+       &lm3533_als_attr_in_illuminance0_thresh1_falling_value.dev_attr.attr,
+       &lm3533_als_attr_in_illuminance0_thresh1_hysteresis.dev_attr.attr,
+       &lm3533_als_attr_in_illuminance0_thresh1_raising_value.dev_attr.attr,
+       &lm3533_als_attr_in_illuminance0_thresh2_falling_value.dev_attr.attr,
+       &lm3533_als_attr_in_illuminance0_thresh2_hysteresis.dev_attr.attr,
+       &lm3533_als_attr_in_illuminance0_thresh2_raising_value.dev_attr.attr,
+       &lm3533_als_attr_in_illuminance0_thresh3_falling_value.dev_attr.attr,
+       &lm3533_als_attr_in_illuminance0_thresh3_hysteresis.dev_attr.attr,
+       &lm3533_als_attr_in_illuminance0_thresh3_raising_value.dev_attr.attr,
+       NULL
+};
+
+static struct attribute_group lm3533_als_event_attribute_group = {
+       .attrs = lm3533_als_event_attributes
+};
+
+static struct attribute *lm3533_als_attributes[] = {
+       &dev_attr_in_illuminance0_zone.attr,
+       &lm3533_als_attr_out_current0_current0_raw.dev_attr.attr,
+       &lm3533_als_attr_out_current0_current1_raw.dev_attr.attr,
+       &lm3533_als_attr_out_current0_current2_raw.dev_attr.attr,
+       &lm3533_als_attr_out_current0_current3_raw.dev_attr.attr,
+       &lm3533_als_attr_out_current0_current4_raw.dev_attr.attr,
+       &lm3533_als_attr_out_current1_current0_raw.dev_attr.attr,
+       &lm3533_als_attr_out_current1_current1_raw.dev_attr.attr,
+       &lm3533_als_attr_out_current1_current2_raw.dev_attr.attr,
+       &lm3533_als_attr_out_current1_current3_raw.dev_attr.attr,
+       &lm3533_als_attr_out_current1_current4_raw.dev_attr.attr,
+       &lm3533_als_attr_out_current2_current0_raw.dev_attr.attr,
+       &lm3533_als_attr_out_current2_current1_raw.dev_attr.attr,
+       &lm3533_als_attr_out_current2_current2_raw.dev_attr.attr,
+       &lm3533_als_attr_out_current2_current3_raw.dev_attr.attr,
+       &lm3533_als_attr_out_current2_current4_raw.dev_attr.attr,
+       NULL
+};
+
+static struct attribute_group lm3533_als_attribute_group = {
+       .attrs = lm3533_als_attributes
+};
+
+static int __devinit lm3533_als_set_input_mode(struct lm3533_als *als,
+                                                               bool pwm_mode)
+{
+       u8 mask = LM3533_ALS_INPUT_MODE_MASK;
+       u8 val;
+       int ret;
+
+       if (pwm_mode)
+               val = mask;     /* pwm input */
+       else
+               val = 0;        /* analog input */
+
+       ret = lm3533_update(als->lm3533, LM3533_REG_ALS_CONF, val, mask);
+       if (ret) {
+               dev_err(&als->pdev->dev, "failed to set input mode %d\n",
+                                                               pwm_mode);
+               return ret;
+       }
+
+       return 0;
+}
+
+static int __devinit lm3533_als_set_resistor(struct lm3533_als *als, u8 val)
+{
+       int ret;
+
+       if (val < LM3533_ALS_RESISTOR_MIN || val > LM3533_ALS_RESISTOR_MAX)
+               return -EINVAL;
+
+       ret = lm3533_write(als->lm3533, LM3533_REG_ALS_RESISTOR_SELECT, val);
+       if (ret) {
+               dev_err(&als->pdev->dev, "failed to set resistor\n");
+               return ret;
+       }
+
+       return 0;
+}
+
+static int __devinit lm3533_als_setup(struct lm3533_als *als,
+                                       struct lm3533_als_platform_data *pdata)
+{
+       int ret;
+
+       ret = lm3533_als_set_input_mode(als, pdata->pwm_mode);
+       if (ret)
+               return ret;
+
+       /* ALS input is always high impedance in PWM-mode. */
+       if (!pdata->pwm_mode) {
+               ret = lm3533_als_set_resistor(als, pdata->r_select);
+               if (ret)
+                       return ret;
+       }
+
+       return 0;
+}
+
+static int __devinit lm3533_als_setup_irq(struct lm3533_als *als, void *dev)
+{
+       u8 mask = LM3533_ALS_INT_ENABLE_MASK;
+       int ret;
+
+       /* Make sure interrupts are disabled. */
+       ret = lm3533_update(als->lm3533, LM3533_REG_ALS_ZONE_INFO, 0, mask);
+       if (ret) {
+               dev_err(&als->pdev->dev, "failed to disable interrupts\n");
+               return ret;
+       }
+
+       ret = request_threaded_irq(als->irq, NULL, lm3533_als_isr,
+                                       IRQF_TRIGGER_LOW | IRQF_ONESHOT,
+                                       dev_name(&als->pdev->dev), dev);
+       if (ret) {
+               dev_err(&als->pdev->dev, "failed to request irq %d\n",
+                                                               als->irq);
+               return ret;
+       }
+
+       return 0;
+}
+
+static int __devinit lm3533_als_enable(struct lm3533_als *als)
+{
+       u8 mask = LM3533_ALS_ENABLE_MASK;
+       int ret;
+
+       ret = lm3533_update(als->lm3533, LM3533_REG_ALS_CONF, mask, mask);
+       if (ret)
+               dev_err(&als->pdev->dev, "failed to enable ALS\n");
+
+       return ret;
+}
+
+static int lm3533_als_disable(struct lm3533_als *als)
+{
+       u8 mask = LM3533_ALS_ENABLE_MASK;
+       int ret;
+
+       ret = lm3533_update(als->lm3533, LM3533_REG_ALS_CONF, 0, mask);
+       if (ret)
+               dev_err(&als->pdev->dev, "failed to disable ALS\n");
+
+       return ret;
+}
+
+static const struct iio_info lm3533_als_info = {
+       .attrs          = &lm3533_als_attribute_group,
+       .event_attrs    = &lm3533_als_event_attribute_group,
+       .driver_module  = THIS_MODULE,
+       .read_raw       = &lm3533_als_read_raw,
+};
+
+static int __devinit lm3533_als_probe(struct platform_device *pdev)
+{
+       struct lm3533 *lm3533;
+       struct lm3533_als_platform_data *pdata;
+       struct lm3533_als *als;
+       struct iio_dev *indio_dev;
+       int ret;
+
+       lm3533 = dev_get_drvdata(pdev->dev.parent);
+       if (!lm3533)
+               return -EINVAL;
+
+       pdata = pdev->dev.platform_data;
+       if (!pdata) {
+               dev_err(&pdev->dev, "no platform data\n");
+               return -EINVAL;
+       }
+
+       indio_dev = iio_device_alloc(sizeof(*als));
+       if (!indio_dev)
+               return -ENOMEM;
+
+       indio_dev->info = &lm3533_als_info;
+       indio_dev->channels = lm3533_als_channels;
+       indio_dev->num_channels = ARRAY_SIZE(lm3533_als_channels);
+       indio_dev->name = dev_name(&pdev->dev);
+       indio_dev->dev.parent = pdev->dev.parent;
+       indio_dev->modes = INDIO_DIRECT_MODE;
+
+       als = iio_priv(indio_dev);
+       als->lm3533 = lm3533;
+       als->pdev = pdev;
+       als->irq = lm3533->irq;
+       atomic_set(&als->zone, 0);
+       mutex_init(&als->thresh_mutex);
+
+       platform_set_drvdata(pdev, indio_dev);
+
+       if (als->irq) {
+               ret = lm3533_als_setup_irq(als, indio_dev);
+               if (ret)
+                       goto err_free_dev;
+       }
+
+       ret = lm3533_als_setup(als, pdata);
+       if (ret)
+               goto err_free_irq;
+
+       ret = lm3533_als_enable(als);
+       if (ret)
+               goto err_free_irq;
+
+       ret = iio_device_register(indio_dev);
+       if (ret) {
+               dev_err(&pdev->dev, "failed to register ALS\n");
+               goto err_disable;
+       }
+
+       return 0;
+
+err_disable:
+       lm3533_als_disable(als);
+err_free_irq:
+       if (als->irq)
+               free_irq(als->irq, indio_dev);
+err_free_dev:
+       iio_device_free(indio_dev);
+
+       return ret;
+}
+
+static int __devexit lm3533_als_remove(struct platform_device *pdev)
+{
+       struct iio_dev *indio_dev = platform_get_drvdata(pdev);
+       struct lm3533_als *als = iio_priv(indio_dev);
+
+       lm3533_als_set_int_mode(indio_dev, false);
+       iio_device_unregister(indio_dev);
+       lm3533_als_disable(als);
+       if (als->irq)
+               free_irq(als->irq, indio_dev);
+       iio_device_free(indio_dev);
+
+       return 0;
+}
+
+static struct platform_driver lm3533_als_driver = {
+       .driver = {
+               .name   = "lm3533-als",
+               .owner  = THIS_MODULE,
+       },
+       .probe          = lm3533_als_probe,
+       .remove         = __devexit_p(lm3533_als_remove),
+};
+module_platform_driver(lm3533_als_driver);
+
+MODULE_AUTHOR("Johan Hovold <jhovold@gmail.com>");
+MODULE_DESCRIPTION("LM3533 Ambient Light Sensor driver");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS("platform:lm3533-als");