These changes are the raw update to linux-4.4.6-rt14. Kernel sources
[kvmfornfv.git] / kernel / drivers / iio / light / opt3001.c
diff --git a/kernel/drivers/iio/light/opt3001.c b/kernel/drivers/iio/light/opt3001.c
new file mode 100644 (file)
index 0000000..01e111e
--- /dev/null
@@ -0,0 +1,803 @@
+/**
+ * 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),
+       },
+};
+
+module_i2c_driver(opt3001_driver);
+
+MODULE_LICENSE("GPL v2");
+MODULE_AUTHOR("Andreas Dannenberg <dannenberg@ti.com>");
+MODULE_DESCRIPTION("Texas Instruments OPT3001 Light Sensor Driver");