iio: light: add support for TI's opt3001 light sensor

TI's opt3001 light sensor is a simple and yet powerful
little device. The device provides 99% IR rejection,
automatic full-scale, very low power consumption and
measurements from 0.01 to 83k lux.

This patch adds support for that device using the IIO
framework.

See http://www.ti.com/product/opt3001 for more information.

Signed-off-by: Felipe Balbi <balbi@ti.com>
Signed-off-by: Andreas Dannenberg <dannenberg@ti.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

3 files changed, 815 insertions, 0 deletions

diff --git a/drivers/iio/light/Kconfig b/drivers/iio/light/Kconfig
index 730fa80c83ea..5c0854a7e3e0 100644
--- a/drivers/iio/light/Kconfig
+++ b/drivers/iio/light/Kconfig
@@ -209,6 +209,16 @@ config LTR501
          This driver can also be built as a module.  If so, the module
          will be called ltr501.
 
+config OPT3001
+        tristate "Texas Instruments OPT3001 Light Sensor"
+        depends on I2C
+        help
+          If you say Y or M here, you get support for Texas Instruments
+          OPT3001 Ambient Light Sensor.
+
+          If built as a dynamically linked module, it will be called
+          opt3001.
+
 config STK3310
         tristate "STK3310 ALS and proximity sensor"
         depends on I2C
diff --git a/drivers/iio/light/Makefile b/drivers/iio/light/Makefile
index adf97237db72..5345969f7000 100644
--- a/drivers/iio/light/Makefile
+++ b/drivers/iio/light/Makefile
@@ -19,6 +19,7 @@ obj-$(CONFIG_ISL29125)		+= isl29125.o
 obj-$(CONFIG_JSA1212)           += jsa1212.o
 obj-$(CONFIG_SENSORS_LM3533)    += lm3533-als.o
 obj-$(CONFIG_LTR501)            += ltr501.o
+obj-$(CONFIG_OPT3001)           += opt3001.o
 obj-$(CONFIG_RPR0521)           += rpr0521.o
 obj-$(CONFIG_SENSORS_TSL2563)   += tsl2563.o
 obj-$(CONFIG_STK3310)          += stk3310.o
diff --git a/drivers/iio/light/opt3001.c b/drivers/iio/light/opt3001.c
new file mode 100644
index 000000000000..923aa6aef0ed
--- /dev/null
+++ b/drivers/iio/light/opt3001.c
@@ -0,0 +1,804 @@
+/**
+ * opt3001.c - Texas Instruments OPT3001 Light Sensor
+ *
+ * Copyright (C) 2014 Texas Instruments Incorporated - http://www.ti.com
+ *
+ * Author: Andreas Dannenberg <dannenberg@ti.com>
+ * Based on previous work from: Felipe Balbi <balbi@ti.com>
+ *
+ * This program is free software: you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 of the License
+ * as published by the Free Software Foundation.
+ *
+ * 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.
+ */
+
+#include <linux/bitops.h>
+#include <linux/delay.h>
+#include <linux/device.h>
+#include <linux/i2c.h>
+#include <linux/interrupt.h>
+#include <linux/irq.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/mutex.h>
+#include <linux/slab.h>
+#include <linux/types.h>
+
+#include <linux/iio/events.h>
+#include <linux/iio/iio.h>
+#include <linux/iio/sysfs.h>
+
+#define OPT3001_RESULT          0x00
+#define OPT3001_CONFIGURATION   0x01
+#define OPT3001_LOW_LIMIT       0x02
+#define OPT3001_HIGH_LIMIT      0x03
+#define OPT3001_MANUFACTURER_ID 0x7e
+#define OPT3001_DEVICE_ID       0x7f
+
+#define OPT3001_CONFIGURATION_RN_MASK   (0xf << 12)
+#define OPT3001_CONFIGURATION_RN_AUTO   (0xc << 12)
+
+#define OPT3001_CONFIGURATION_CT        BIT(11)
+
+#define OPT3001_CONFIGURATION_M_MASK    (3 << 9)
+#define OPT3001_CONFIGURATION_M_SHUTDOWN (0 << 9)
+#define OPT3001_CONFIGURATION_M_SINGLE  (1 << 9)
+#define OPT3001_CONFIGURATION_M_CONTINUOUS (2 << 9) /* also 3 << 9 */
+
+#define OPT3001_CONFIGURATION_OVF       BIT(8)
+#define OPT3001_CONFIGURATION_CRF       BIT(7)
+#define OPT3001_CONFIGURATION_FH        BIT(6)
+#define OPT3001_CONFIGURATION_FL        BIT(5)
+#define OPT3001_CONFIGURATION_L         BIT(4)
+#define OPT3001_CONFIGURATION_POL       BIT(3)
+#define OPT3001_CONFIGURATION_ME        BIT(2)
+
+#define OPT3001_CONFIGURATION_FC_MASK   (3 << 0)
+
+/* The end-of-conversion enable is located in the low-limit register */
+#define OPT3001_LOW_LIMIT_EOC_ENABLE    0xc000
+
+#define OPT3001_REG_EXPONENT(n)         ((n) >> 12)
+#define OPT3001_REG_MANTISSA(n)         ((n) & 0xfff)
+
+/*
+ * Time to wait for conversion result to be ready. The device datasheet
+ * worst-case max value is 880ms. Add some slack to be on the safe side.
+ */
+#define OPT3001_RESULT_READY_TIMEOUT    msecs_to_jiffies(1000)
+
+struct opt3001 {
+        struct i2c_client       *client;
+        struct device           *dev;
+
+        struct mutex            lock;
+        u16                     ok_to_ignore_lock:1;
+        u16                     result_ready:1;
+        wait_queue_head_t       result_ready_queue;
+        u16                     result;
+
+        u32                     int_time;
+        u32                     mode;
+
+        u16                     high_thresh_mantissa;
+        u16                     low_thresh_mantissa;
+
+        u8                      high_thresh_exp;
+        u8                      low_thresh_exp;
+};
+
+struct opt3001_scale {
+        int     val;
+        int     val2;
+};
+
+static const struct opt3001_scale opt3001_scales[] = {
+        {
+                .val = 40,
+                .val2 = 950000,
+        },
+        {
+                .val = 81,
+                .val2 = 900000,
+        },
+        {
+                .val = 163,
+                .val2 = 800000,
+        },
+        {
+                .val = 327,
+                .val2 = 600000,
+        },
+        {
+                .val = 655,
+                .val2 = 200000,
+        },
+        {
+                .val = 1310,
+                .val2 = 400000,
+        },
+        {
+                .val = 2620,
+                .val2 = 800000,
+        },
+        {
+                .val = 5241,
+                .val2 = 600000,
+        },
+        {
+                .val = 10483,
+                .val2 = 200000,
+        },
+        {
+                .val = 20966,
+                .val2 = 400000,
+        },
+        {
+                .val = 83865,
+                .val2 = 600000,
+        },
+};
+
+static int opt3001_find_scale(const struct opt3001 *opt, int val,
+                int val2, u8 *exponent)
+{
+        int i;
+
+        for (i = 0; i < ARRAY_SIZE(opt3001_scales); i++) {
+                const struct opt3001_scale *scale = &opt3001_scales[i];
+
+                /*
+                 * Combine the integer and micro parts for comparison
+                 * purposes. Use milli lux precision to avoid 32-bit integer
+                 * overflows.
+                 */
+                if ((val * 1000 + val2 / 1000) <=
+                                (scale->val * 1000 + scale->val2 / 1000)) {
+                        *exponent = i;
+                        return 0;
+                }
+        }
+
+        return -EINVAL;
+}
+
+static void opt3001_to_iio_ret(struct opt3001 *opt, u8 exponent,
+                u16 mantissa, int *val, int *val2)
+{
+        int lux;
+
+        lux = 10 * (mantissa << exponent);
+        *val = lux / 1000;
+        *val2 = (lux - (*val * 1000)) * 1000;
+}
+
+static void opt3001_set_mode(struct opt3001 *opt, u16 *reg, u16 mode)
+{
+        *reg &= ~OPT3001_CONFIGURATION_M_MASK;
+        *reg |= mode;
+        opt->mode = mode;
+}
+
+static IIO_CONST_ATTR_INT_TIME_AVAIL("0.1 0.8");
+
+static struct attribute *opt3001_attributes[] = {
+        &iio_const_attr_integration_time_available.dev_attr.attr,
+        NULL
+};
+
+static const struct attribute_group opt3001_attribute_group = {
+        .attrs = opt3001_attributes,
+};
+
+static const struct iio_event_spec opt3001_event_spec[] = {
+        {
+                .type = IIO_EV_TYPE_THRESH,
+                .dir = IIO_EV_DIR_RISING,
+                .mask_separate = BIT(IIO_EV_INFO_VALUE) |
+                        BIT(IIO_EV_INFO_ENABLE),
+        },
+        {
+                .type = IIO_EV_TYPE_THRESH,
+                .dir = IIO_EV_DIR_FALLING,
+                .mask_separate = BIT(IIO_EV_INFO_VALUE) |
+                        BIT(IIO_EV_INFO_ENABLE),
+        },
+};
+
+static const struct iio_chan_spec opt3001_channels[] = {
+        {
+                .type = IIO_LIGHT,
+                .info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED) |
+                                BIT(IIO_CHAN_INFO_INT_TIME),
+                .event_spec = opt3001_event_spec,
+                .num_event_specs = ARRAY_SIZE(opt3001_event_spec),
+        },
+        IIO_CHAN_SOFT_TIMESTAMP(1),
+};
+
+static int opt3001_get_lux(struct opt3001 *opt, int *val, int *val2)
+{
+        int ret;
+        u16 mantissa;
+        u16 reg;
+        u8 exponent;
+        u16 value;
+
+        /*
+         * Enable the end-of-conversion interrupt mechanism. Note that doing
+         * so will overwrite the low-level limit value however we will restore
+         * this value later on.
+         */
+        ret = i2c_smbus_write_word_swapped(opt->client, OPT3001_LOW_LIMIT,
+                        OPT3001_LOW_LIMIT_EOC_ENABLE);
+        if (ret < 0) {
+                dev_err(opt->dev, "failed to write register %02x\n",
+                                OPT3001_LOW_LIMIT);
+                return ret;
+        }
+
+        /* Reset data-ready indicator flag (will be set in the IRQ routine) */
+        opt->result_ready = false;
+
+        /* Allow IRQ to access the device despite lock being set */
+        opt->ok_to_ignore_lock = true;
+
+        /* Configure for single-conversion mode and start a new conversion */
+        ret = i2c_smbus_read_word_swapped(opt->client, OPT3001_CONFIGURATION);
+        if (ret < 0) {
+                dev_err(opt->dev, "failed to read register %02x\n",
+                                OPT3001_CONFIGURATION);
+                goto err;
+        }
+
+        reg = ret;
+        opt3001_set_mode(opt, &reg, OPT3001_CONFIGURATION_M_SINGLE);
+
+        ret = i2c_smbus_write_word_swapped(opt->client, OPT3001_CONFIGURATION,
+                        reg);
+        if (ret < 0) {
+                dev_err(opt->dev, "failed to write register %02x\n",
+                                OPT3001_CONFIGURATION);
+                goto err;
+        }
+
+        /* Wait for the IRQ to indicate the conversion is complete */
+        ret = wait_event_timeout(opt->result_ready_queue, opt->result_ready,
+                        OPT3001_RESULT_READY_TIMEOUT);
+
+err:
+        /* Disallow IRQ to access the device while lock is active */
+        opt->ok_to_ignore_lock = false;
+
+        if (ret == 0)
+                return -ETIMEDOUT;
+        else if (ret < 0)
+                return ret;
+
+        /*
+         * Disable the end-of-conversion interrupt mechanism by restoring the
+         * low-level limit value (clearing OPT3001_LOW_LIMIT_EOC_ENABLE). Note
+         * that selectively clearing those enable bits would affect the actual
+         * limit value due to bit-overlap and therefore can't be done.
+         */
+        value = (opt->low_thresh_exp << 12) | opt->low_thresh_mantissa;
+        ret = i2c_smbus_write_word_swapped(opt->client, OPT3001_LOW_LIMIT,
+                        value);
+        if (ret < 0) {
+                dev_err(opt->dev, "failed to write register %02x\n",
+                                OPT3001_LOW_LIMIT);
+                return ret;
+        }
+
+        exponent = OPT3001_REG_EXPONENT(opt->result);
+        mantissa = OPT3001_REG_MANTISSA(opt->result);
+
+        opt3001_to_iio_ret(opt, exponent, mantissa, val, val2);
+
+        return IIO_VAL_INT_PLUS_MICRO;
+}
+
+static int opt3001_get_int_time(struct opt3001 *opt, int *val, int *val2)
+{
+        *val = 0;
+        *val2 = opt->int_time;
+
+        return IIO_VAL_INT_PLUS_MICRO;
+}
+
+static int opt3001_set_int_time(struct opt3001 *opt, int time)
+{
+        int ret;
+        u16 reg;
+
+        ret = i2c_smbus_read_word_swapped(opt->client, OPT3001_CONFIGURATION);
+        if (ret < 0) {
+                dev_err(opt->dev, "failed to read register %02x\n",
+                                OPT3001_CONFIGURATION);
+                return ret;
+        }
+
+        reg = ret;
+
+        switch (time) {
+        case 100000:
+                reg &= ~OPT3001_CONFIGURATION_CT;
+                opt->int_time = 100000;
+                break;
+        case 800000:
+                reg |= OPT3001_CONFIGURATION_CT;
+                opt->int_time = 800000;
+                break;
+        default:
+                return -EINVAL;
+        }
+
+        return i2c_smbus_write_word_swapped(opt->client, OPT3001_CONFIGURATION,
+                        reg);
+}
+
+static int opt3001_read_raw(struct iio_dev *iio,
+                struct iio_chan_spec const *chan, int *val, int *val2,
+                long mask)
+{
+        struct opt3001 *opt = iio_priv(iio);
+        int ret;
+
+        if (opt->mode == OPT3001_CONFIGURATION_M_CONTINUOUS)
+                return -EBUSY;
+
+        if (chan->type != IIO_LIGHT)
+                return -EINVAL;
+
+        mutex_lock(&opt->lock);
+
+        switch (mask) {
+        case IIO_CHAN_INFO_PROCESSED:
+                ret = opt3001_get_lux(opt, val, val2);
+                break;
+        case IIO_CHAN_INFO_INT_TIME:
+                ret = opt3001_get_int_time(opt, val, val2);
+                break;
+        default:
+                ret = -EINVAL;
+        }
+
+        mutex_unlock(&opt->lock);
+
+        return ret;
+}
+
+static int opt3001_write_raw(struct iio_dev *iio,
+                struct iio_chan_spec const *chan, int val, int val2,
+                long mask)
+{
+        struct opt3001 *opt = iio_priv(iio);
+        int ret;
+
+        if (opt->mode == OPT3001_CONFIGURATION_M_CONTINUOUS)
+                return -EBUSY;
+
+        if (chan->type != IIO_LIGHT)
+                return -EINVAL;
+
+        if (mask != IIO_CHAN_INFO_INT_TIME)
+                return -EINVAL;
+
+        if (val != 0)
+                return -EINVAL;
+
+        mutex_lock(&opt->lock);
+        ret = opt3001_set_int_time(opt, val2);
+        mutex_unlock(&opt->lock);
+
+        return ret;
+}
+
+static int opt3001_read_event_value(struct iio_dev *iio,
+                const struct iio_chan_spec *chan, enum iio_event_type type,
+                enum iio_event_direction dir, enum iio_event_info info,
+                int *val, int *val2)
+{
+        struct opt3001 *opt = iio_priv(iio);
+        int ret = IIO_VAL_INT_PLUS_MICRO;
+
+        mutex_lock(&opt->lock);
+
+        switch (dir) {
+        case IIO_EV_DIR_RISING:
+                opt3001_to_iio_ret(opt, opt->high_thresh_exp,
+                                opt->high_thresh_mantissa, val, val2);
+                break;
+        case IIO_EV_DIR_FALLING:
+                opt3001_to_iio_ret(opt, opt->low_thresh_exp,
+                                opt->low_thresh_mantissa, val, val2);
+                break;
+        default:
+                ret = -EINVAL;
+        }
+
+        mutex_unlock(&opt->lock);
+
+        return ret;
+}
+
+static int opt3001_write_event_value(struct iio_dev *iio,
+                const struct iio_chan_spec *chan, enum iio_event_type type,
+                enum iio_event_direction dir, enum iio_event_info info,
+                int val, int val2)
+{
+        struct opt3001 *opt = iio_priv(iio);
+        int ret;
+
+        u16 mantissa;
+        u16 value;
+        u16 reg;
+
+        u8 exponent;
+
+        if (val < 0)
+                return -EINVAL;
+
+        mutex_lock(&opt->lock);
+
+        ret = opt3001_find_scale(opt, val, val2, &exponent);
+        if (ret < 0) {
+                dev_err(opt->dev, "can't find scale for %d.%06u\n", val, val2);
+                goto err;
+        }
+
+        mantissa = (((val * 1000) + (val2 / 1000)) / 10) >> exponent;
+        value = (exponent << 12) | mantissa;
+
+        switch (dir) {
+        case IIO_EV_DIR_RISING:
+                reg = OPT3001_HIGH_LIMIT;
+                opt->high_thresh_mantissa = mantissa;
+                opt->high_thresh_exp = exponent;
+                break;
+        case IIO_EV_DIR_FALLING:
+                reg = OPT3001_LOW_LIMIT;
+                opt->low_thresh_mantissa = mantissa;
+                opt->low_thresh_exp = exponent;
+                break;
+        default:
+                ret = -EINVAL;
+                goto err;
+        }
+
+        ret = i2c_smbus_write_word_swapped(opt->client, reg, value);
+        if (ret < 0) {
+                dev_err(opt->dev, "failed to write register %02x\n", reg);
+                goto err;
+        }
+
+err:
+        mutex_unlock(&opt->lock);
+
+        return ret;
+}
+
+static int opt3001_read_event_config(struct iio_dev *iio,
+                const struct iio_chan_spec *chan, enum iio_event_type type,
+                enum iio_event_direction dir)
+{
+        struct opt3001 *opt = iio_priv(iio);
+
+        return opt->mode == OPT3001_CONFIGURATION_M_CONTINUOUS;
+}
+
+static int opt3001_write_event_config(struct iio_dev *iio,
+                const struct iio_chan_spec *chan, enum iio_event_type type,
+                enum iio_event_direction dir, int state)
+{
+        struct opt3001 *opt = iio_priv(iio);
+        int ret;
+        u16 mode;
+        u16 reg;
+
+        if (state && opt->mode == OPT3001_CONFIGURATION_M_CONTINUOUS)
+                return 0;
+
+        if (!state && opt->mode == OPT3001_CONFIGURATION_M_SHUTDOWN)
+                return 0;
+
+        mutex_lock(&opt->lock);
+
+        mode = state ? OPT3001_CONFIGURATION_M_CONTINUOUS
+                : OPT3001_CONFIGURATION_M_SHUTDOWN;
+
+        ret = i2c_smbus_read_word_swapped(opt->client, OPT3001_CONFIGURATION);
+        if (ret < 0) {
+                dev_err(opt->dev, "failed to read register %02x\n",
+                                OPT3001_CONFIGURATION);
+                goto err;
+        }
+
+        reg = ret;
+        opt3001_set_mode(opt, &reg, mode);
+
+        ret = i2c_smbus_write_word_swapped(opt->client, OPT3001_CONFIGURATION,
+                        reg);
+        if (ret < 0) {
+                dev_err(opt->dev, "failed to write register %02x\n",
+                                OPT3001_CONFIGURATION);
+                goto err;
+        }
+
+err:
+        mutex_unlock(&opt->lock);
+
+        return ret;
+}
+
+static const struct iio_info opt3001_info = {
+        .driver_module = THIS_MODULE,
+        .attrs = &opt3001_attribute_group,
+        .read_raw = opt3001_read_raw,
+        .write_raw = opt3001_write_raw,
+        .read_event_value = opt3001_read_event_value,
+        .write_event_value = opt3001_write_event_value,
+        .read_event_config = opt3001_read_event_config,
+        .write_event_config = opt3001_write_event_config,
+};
+
+static int opt3001_read_id(struct opt3001 *opt)
+{
+        char manufacturer[2];
+        u16 device_id;
+        int ret;
+
+        ret = i2c_smbus_read_word_swapped(opt->client, OPT3001_MANUFACTURER_ID);
+        if (ret < 0) {
+                dev_err(opt->dev, "failed to read register %02x\n",
+                                OPT3001_MANUFACTURER_ID);
+                return ret;
+        }
+
+        manufacturer[0] = ret >> 8;
+        manufacturer[1] = ret & 0xff;
+
+        ret = i2c_smbus_read_word_swapped(opt->client, OPT3001_DEVICE_ID);
+        if (ret < 0) {
+                dev_err(opt->dev, "failed to read register %02x\n",
+                                OPT3001_DEVICE_ID);
+                return ret;
+        }
+
+        device_id = ret;
+
+        dev_info(opt->dev, "Found %c%c OPT%04x\n", manufacturer[0],
+                        manufacturer[1], device_id);
+
+        return 0;
+}
+
+static int opt3001_configure(struct opt3001 *opt)
+{
+        int ret;
+        u16 reg;
+
+        ret = i2c_smbus_read_word_swapped(opt->client, OPT3001_CONFIGURATION);
+        if (ret < 0) {
+                dev_err(opt->dev, "failed to read register %02x\n",
+                                OPT3001_CONFIGURATION);
+                return ret;
+        }
+
+        reg = ret;
+
+        /* Enable automatic full-scale setting mode */
+        reg &= ~OPT3001_CONFIGURATION_RN_MASK;
+        reg |= OPT3001_CONFIGURATION_RN_AUTO;
+
+        /* Reflect status of the device's integration time setting */
+        if (reg & OPT3001_CONFIGURATION_CT)
+                opt->int_time = 800000;
+        else
+                opt->int_time = 100000;
+
+        /* Ensure device is in shutdown initially */
+        opt3001_set_mode(opt, &reg, OPT3001_CONFIGURATION_M_SHUTDOWN);
+
+        /* Configure for latched window-style comparison operation */
+        reg |= OPT3001_CONFIGURATION_L;
+        reg &= ~OPT3001_CONFIGURATION_POL;
+        reg &= ~OPT3001_CONFIGURATION_ME;
+        reg &= ~OPT3001_CONFIGURATION_FC_MASK;
+
+        ret = i2c_smbus_write_word_swapped(opt->client, OPT3001_CONFIGURATION,
+                        reg);
+        if (ret < 0) {
+                dev_err(opt->dev, "failed to write register %02x\n",
+                                OPT3001_CONFIGURATION);
+                return ret;
+        }
+
+        ret = i2c_smbus_read_word_swapped(opt->client, OPT3001_LOW_LIMIT);
+        if (ret < 0) {
+                dev_err(opt->dev, "failed to read register %02x\n",
+                                OPT3001_LOW_LIMIT);
+                return ret;
+        }
+
+        opt->low_thresh_mantissa = OPT3001_REG_MANTISSA(ret);
+        opt->low_thresh_exp = OPT3001_REG_EXPONENT(ret);
+
+        ret = i2c_smbus_read_word_swapped(opt->client, OPT3001_HIGH_LIMIT);
+        if (ret < 0) {
+                dev_err(opt->dev, "failed to read register %02x\n",
+                                OPT3001_HIGH_LIMIT);
+                return ret;
+        }
+
+        opt->high_thresh_mantissa = OPT3001_REG_MANTISSA(ret);
+        opt->high_thresh_exp = OPT3001_REG_EXPONENT(ret);
+
+        return 0;
+}
+
+static irqreturn_t opt3001_irq(int irq, void *_iio)
+{
+        struct iio_dev *iio = _iio;
+        struct opt3001 *opt = iio_priv(iio);
+        int ret;
+
+        if (!opt->ok_to_ignore_lock)
+                mutex_lock(&opt->lock);
+
+        ret = i2c_smbus_read_word_swapped(opt->client, OPT3001_CONFIGURATION);
+        if (ret < 0) {
+                dev_err(opt->dev, "failed to read register %02x\n",
+                                OPT3001_CONFIGURATION);
+                goto out;
+        }
+
+        if ((ret & OPT3001_CONFIGURATION_M_MASK) ==
+                        OPT3001_CONFIGURATION_M_CONTINUOUS) {
+                if (ret & OPT3001_CONFIGURATION_FH)
+                        iio_push_event(iio,
+                                        IIO_UNMOD_EVENT_CODE(IIO_LIGHT, 0,
+                                                        IIO_EV_TYPE_THRESH,
+                                                        IIO_EV_DIR_RISING),
+                                        iio_get_time_ns());
+                if (ret & OPT3001_CONFIGURATION_FL)
+                        iio_push_event(iio,
+                                        IIO_UNMOD_EVENT_CODE(IIO_LIGHT, 0,
+                                                        IIO_EV_TYPE_THRESH,
+                                                        IIO_EV_DIR_FALLING),
+                                        iio_get_time_ns());
+        } else if (ret & OPT3001_CONFIGURATION_CRF) {
+                ret = i2c_smbus_read_word_swapped(opt->client, OPT3001_RESULT);
+                if (ret < 0) {
+                        dev_err(opt->dev, "failed to read register %02x\n",
+                                        OPT3001_RESULT);
+                        goto out;
+                }
+                opt->result = ret;
+                opt->result_ready = true;
+                wake_up(&opt->result_ready_queue);
+        }
+
+out:
+        if (!opt->ok_to_ignore_lock)
+                mutex_unlock(&opt->lock);
+
+        return IRQ_HANDLED;
+}
+
+static int opt3001_probe(struct i2c_client *client,
+                const struct i2c_device_id *id)
+{
+        struct device *dev = &client->dev;
+
+        struct iio_dev *iio;
+        struct opt3001 *opt;
+        int irq = client->irq;
+        int ret;
+
+        iio = devm_iio_device_alloc(dev, sizeof(*opt));
+        if (!iio)
+                return -ENOMEM;
+
+        opt = iio_priv(iio);
+        opt->client = client;
+        opt->dev = dev;
+
+        mutex_init(&opt->lock);
+        init_waitqueue_head(&opt->result_ready_queue);
+        i2c_set_clientdata(client, iio);
+
+        ret = opt3001_read_id(opt);
+        if (ret)
+                return ret;
+
+        ret = opt3001_configure(opt);
+        if (ret)
+                return ret;
+
+        iio->name = client->name;
+        iio->channels = opt3001_channels;
+        iio->num_channels = ARRAY_SIZE(opt3001_channels);
+        iio->dev.parent = dev;
+        iio->modes = INDIO_DIRECT_MODE;
+        iio->info = &opt3001_info;
+
+        ret = devm_iio_device_register(dev, iio);
+        if (ret) {
+                dev_err(dev, "failed to register IIO device\n");
+                return ret;
+        }
+
+        ret = request_threaded_irq(irq, NULL, opt3001_irq,
+                        IRQF_TRIGGER_FALLING | IRQF_ONESHOT,
+                        "opt3001", iio);
+        if (ret) {
+                dev_err(dev, "failed to request IRQ #%d\n", irq);
+                return ret;
+        }
+
+        return 0;
+}
+
+static int opt3001_remove(struct i2c_client *client)
+{
+        struct iio_dev *iio = i2c_get_clientdata(client);
+        struct opt3001 *opt = iio_priv(iio);
+        int ret;
+        u16 reg;
+
+        free_irq(client->irq, iio);
+
+        ret = i2c_smbus_read_word_swapped(opt->client, OPT3001_CONFIGURATION);
+        if (ret < 0) {
+                dev_err(opt->dev, "failed to read register %02x\n",
+                                OPT3001_CONFIGURATION);
+                return ret;
+        }
+
+        reg = ret;
+        opt3001_set_mode(opt, &reg, OPT3001_CONFIGURATION_M_SHUTDOWN);
+
+        ret = i2c_smbus_write_word_swapped(opt->client, OPT3001_CONFIGURATION,
+                        reg);
+        if (ret < 0) {
+                dev_err(opt->dev, "failed to write register %02x\n",
+                                OPT3001_CONFIGURATION);
+                return ret;
+        }
+
+        return 0;
+}
+
+static const struct i2c_device_id opt3001_id[] = {
+        { "opt3001", 0 },
+        { } /* Terminating Entry */
+};
+MODULE_DEVICE_TABLE(i2c, opt3001_id);
+
+static const struct of_device_id opt3001_of_match[] = {
+        { .compatible = "ti,opt3001" },
+        { }
+};
+
+static struct i2c_driver opt3001_driver = {
+        .probe = opt3001_probe,
+        .remove = opt3001_remove,
+        .id_table = opt3001_id,
+
+        .driver = {
+                .name = "opt3001",
+                .of_match_table = of_match_ptr(opt3001_of_match),
+                .owner = THIS_MODULE,
+        },
+};
+
+module_i2c_driver(opt3001_driver);
+
+MODULE_LICENSE("GPL v2");
+MODULE_AUTHOR("Andreas Dannenberg <dannenberg@ti.com>");
+MODULE_DESCRIPTION("Texas Instruments OPT3001 Light Sensor Driver");