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![Daniel Baluta](/assets/img/avatar_default.png)
Minimal implementation. This driver provides raw illuminance readings. This is based on drivers/hwmon/al3320.c (*) driver from msm tree written by Tsechih Lin <Tsechih_Lin@asus.com> * https://android.googlesource.com/kernel/msm.git Signed-off-by: Daniel Baluta <daniel.baluta@intel.com> Reviewed-by: Hartmut Knaack <knaack.h@gmx.de> Signed-off-by: Jonathan Cameron <jic23@kernel.org>
232 lines
5.6 KiB
C
232 lines
5.6 KiB
C
/*
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* AL3320A - Dyna Image Ambient Light Sensor
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*
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* Copyright (c) 2014, Intel Corporation.
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*
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* This file is subject to the terms and conditions of version 2 of
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* the GNU General Public License. See the file COPYING in the main
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* directory of this archive for more details.
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*
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* IIO driver for AL3320A (7-bit I2C slave address 0x1C).
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*
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* TODO: interrupt support, thresholds
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*
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*/
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#include <linux/module.h>
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#include <linux/init.h>
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#include <linux/i2c.h>
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#include <linux/iio/iio.h>
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#include <linux/iio/sysfs.h>
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#define AL3320A_DRV_NAME "al3320a"
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#define AL3320A_REG_CONFIG 0x00
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#define AL3320A_REG_STATUS 0x01
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#define AL3320A_REG_INT 0x02
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#define AL3320A_REG_WAIT 0x06
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#define AL3320A_REG_CONFIG_RANGE 0x07
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#define AL3320A_REG_PERSIST 0x08
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#define AL3320A_REG_MEAN_TIME 0x09
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#define AL3320A_REG_ADUMMY 0x0A
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#define AL3320A_REG_DATA_LOW 0x22
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#define AL3320A_REG_LOW_THRESH_LOW 0x30
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#define AL3320A_REG_LOW_THRESH_HIGH 0x31
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#define AL3320A_REG_HIGH_THRESH_LOW 0x32
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#define AL3320A_REG_HIGH_THRESH_HIGH 0x33
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#define AL3320A_CONFIG_DISABLE 0x00
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#define AL3320A_CONFIG_ENABLE 0x01
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#define AL3320A_GAIN_SHIFT 1
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#define AL3320A_GAIN_MASK (BIT(2) | BIT(1))
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/* chip params default values */
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#define AL3320A_DEFAULT_MEAN_TIME 4
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#define AL3320A_DEFAULT_WAIT_TIME 0 /* no waiting */
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#define AL3320A_SCALE_AVAILABLE "0.512 0.128 0.032 0.01"
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enum al3320a_range {
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AL3320A_RANGE_1, /* 33.28 Klx */
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AL3320A_RANGE_2, /* 8.32 Klx */
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AL3320A_RANGE_3, /* 2.08 Klx */
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AL3320A_RANGE_4 /* 0.65 Klx */
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};
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static const int al3320a_scales[][2] = {
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{0, 512000}, {0, 128000}, {0, 32000}, {0, 10000}
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};
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struct al3320a_data {
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struct i2c_client *client;
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};
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static const struct iio_chan_spec al3320a_channels[] = {
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{
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.type = IIO_LIGHT,
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.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
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BIT(IIO_CHAN_INFO_SCALE),
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}
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};
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static IIO_CONST_ATTR(in_illuminance_scale_available, AL3320A_SCALE_AVAILABLE);
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static struct attribute *al3320a_attributes[] = {
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&iio_const_attr_in_illuminance_scale_available.dev_attr.attr,
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NULL,
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};
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static const struct attribute_group al3320a_attribute_group = {
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.attrs = al3320a_attributes,
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};
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static int al3320a_init(struct al3320a_data *data)
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{
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int ret;
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/* power on */
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ret = i2c_smbus_write_byte_data(data->client, AL3320A_REG_CONFIG,
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AL3320A_CONFIG_ENABLE);
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if (ret < 0)
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return ret;
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ret = i2c_smbus_write_byte_data(data->client, AL3320A_REG_CONFIG_RANGE,
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AL3320A_RANGE_3 << AL3320A_GAIN_SHIFT);
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if (ret < 0)
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return ret;
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ret = i2c_smbus_write_byte_data(data->client, AL3320A_REG_MEAN_TIME,
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AL3320A_DEFAULT_MEAN_TIME);
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if (ret < 0)
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return ret;
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ret = i2c_smbus_write_byte_data(data->client, AL3320A_REG_WAIT,
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AL3320A_DEFAULT_WAIT_TIME);
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if (ret < 0)
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return ret;
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return 0;
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}
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static int al3320a_read_raw(struct iio_dev *indio_dev,
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struct iio_chan_spec const *chan, int *val,
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int *val2, long mask)
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{
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struct al3320a_data *data = iio_priv(indio_dev);
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int ret;
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switch (mask) {
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case IIO_CHAN_INFO_RAW:
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/*
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* ALS ADC value is stored in two adjacent registers:
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* - low byte of output is stored at AL3320A_REG_DATA_LOW
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* - high byte of output is stored at AL3320A_REG_DATA_LOW + 1
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*/
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ret = i2c_smbus_read_word_data(data->client,
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AL3320A_REG_DATA_LOW);
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if (ret < 0)
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return ret;
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*val = ret;
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return IIO_VAL_INT;
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case IIO_CHAN_INFO_SCALE:
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ret = i2c_smbus_read_byte_data(data->client,
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AL3320A_REG_CONFIG_RANGE);
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if (ret < 0)
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return ret;
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ret = (ret & AL3320A_GAIN_MASK) >> AL3320A_GAIN_SHIFT;
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*val = al3320a_scales[ret][0];
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*val2 = al3320a_scales[ret][1];
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return IIO_VAL_INT_PLUS_MICRO;
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}
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return -EINVAL;
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}
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static int al3320a_write_raw(struct iio_dev *indio_dev,
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struct iio_chan_spec const *chan, int val,
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int val2, long mask)
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{
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struct al3320a_data *data = iio_priv(indio_dev);
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int i;
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switch (mask) {
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case IIO_CHAN_INFO_SCALE:
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for (i = 0; i < ARRAY_SIZE(al3320a_scales); i++) {
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if (val == al3320a_scales[i][0] &&
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val2 == al3320a_scales[i][1])
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return i2c_smbus_write_byte_data(data->client,
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AL3320A_REG_CONFIG_RANGE,
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i << AL3320A_GAIN_SHIFT);
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}
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break;
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}
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return -EINVAL;
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}
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static const struct iio_info al3320a_info = {
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.driver_module = THIS_MODULE,
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.read_raw = al3320a_read_raw,
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.write_raw = al3320a_write_raw,
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.attrs = &al3320a_attribute_group,
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};
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static int al3320a_probe(struct i2c_client *client,
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const struct i2c_device_id *id)
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{
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struct al3320a_data *data;
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struct iio_dev *indio_dev;
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int ret;
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indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));
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if (!indio_dev)
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return -ENOMEM;
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data = iio_priv(indio_dev);
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i2c_set_clientdata(client, indio_dev);
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data->client = client;
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indio_dev->dev.parent = &client->dev;
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indio_dev->info = &al3320a_info;
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indio_dev->name = AL3320A_DRV_NAME;
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indio_dev->channels = al3320a_channels;
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indio_dev->num_channels = ARRAY_SIZE(al3320a_channels);
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indio_dev->modes = INDIO_DIRECT_MODE;
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ret = al3320a_init(data);
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if (ret < 0) {
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dev_err(&client->dev, "al3320a chip init failed\n");
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return ret;
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}
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return devm_iio_device_register(&client->dev, indio_dev);
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}
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static int al3320a_remove(struct i2c_client *client)
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{
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return i2c_smbus_write_byte_data(client, AL3320A_REG_CONFIG,
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AL3320A_CONFIG_DISABLE);
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}
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static const struct i2c_device_id al3320a_id[] = {
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{"al3320a", 0},
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{}
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};
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MODULE_DEVICE_TABLE(i2c, al3320a_id);
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static struct i2c_driver al3320a_driver = {
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.driver = {
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.name = AL3320A_DRV_NAME,
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},
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.probe = al3320a_probe,
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.remove = al3320a_remove,
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.id_table = al3320a_id,
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};
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module_i2c_driver(al3320a_driver);
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MODULE_AUTHOR("Daniel Baluta <daniel.baluta@intel.com>");
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MODULE_DESCRIPTION("AL3320A Ambient Light Sensor driver");
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MODULE_LICENSE("GPL v2");
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