266 lines
6.4 KiB
C
266 lines
6.4 KiB
C
// SPDX-License-Identifier: GPL-2.0-only
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/*
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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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* 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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* When the driver will get support for interrupt handling, then interrupt
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* will need to be disabled before turning sensor OFF in order to avoid
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* potential races with the interrupt handling.
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*/
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#include <linux/bitfield.h>
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#include <linux/i2c.h>
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#include <linux/module.h>
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#include <linux/of.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_MASK GENMASK(2, 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_set_pwr(struct i2c_client *client, bool pwr)
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{
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u8 val = pwr ? AL3320A_CONFIG_ENABLE : AL3320A_CONFIG_DISABLE;
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return i2c_smbus_write_byte_data(client, AL3320A_REG_CONFIG, val);
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}
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static void al3320a_set_pwr_off(void *_data)
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{
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struct al3320a_data *data = _data;
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al3320a_set_pwr(data->client, false);
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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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ret = al3320a_set_pwr(data->client, true);
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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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FIELD_PREP(AL3320A_GAIN_MASK,
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AL3320A_RANGE_3));
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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 = FIELD_GET(AL3320A_GAIN_MASK, ret);
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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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continue;
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return i2c_smbus_write_byte_data(data->client,
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AL3320A_REG_CONFIG_RANGE,
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FIELD_PREP(AL3320A_GAIN_MASK, i));
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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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.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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ret = devm_add_action_or_reset(&client->dev,
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al3320a_set_pwr_off,
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data);
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if (ret < 0)
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return ret;
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return devm_iio_device_register(&client->dev, indio_dev);
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}
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static int __maybe_unused al3320a_suspend(struct device *dev)
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{
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return al3320a_set_pwr(to_i2c_client(dev), false);
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}
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static int __maybe_unused al3320a_resume(struct device *dev)
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{
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return al3320a_set_pwr(to_i2c_client(dev), true);
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}
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static SIMPLE_DEV_PM_OPS(al3320a_pm_ops, al3320a_suspend, al3320a_resume);
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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 const struct of_device_id al3320a_of_match[] = {
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{ .compatible = "dynaimage,al3320a", },
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{},
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};
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MODULE_DEVICE_TABLE(of, al3320a_of_match);
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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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.of_match_table = al3320a_of_match,
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.pm = &al3320a_pm_ops,
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},
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.probe = al3320a_probe,
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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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