446 lines
11 KiB
C
446 lines
11 KiB
C
/*
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* ltr501.c - Support for Lite-On LTR501 ambient light and proximity sensor
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*
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* Copyright 2014 Peter Meerwald <pmeerw@pmeerw.net>
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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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* 7-bit I2C slave address 0x23
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*
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* TODO: interrupt, threshold, measurement rate, IR LED characteristics
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*/
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#include <linux/module.h>
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#include <linux/i2c.h>
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#include <linux/err.h>
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#include <linux/delay.h>
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#include <linux/iio/iio.h>
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#include <linux/iio/sysfs.h>
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#include <linux/iio/trigger_consumer.h>
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#include <linux/iio/buffer.h>
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#include <linux/iio/triggered_buffer.h>
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#define LTR501_DRV_NAME "ltr501"
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#define LTR501_ALS_CONTR 0x80 /* ALS operation mode, SW reset */
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#define LTR501_PS_CONTR 0x81 /* PS operation mode */
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#define LTR501_PART_ID 0x86
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#define LTR501_MANUFAC_ID 0x87
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#define LTR501_ALS_DATA1 0x88 /* 16-bit, little endian */
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#define LTR501_ALS_DATA0 0x8a /* 16-bit, little endian */
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#define LTR501_ALS_PS_STATUS 0x8c
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#define LTR501_PS_DATA 0x8d /* 16-bit, little endian */
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#define LTR501_ALS_CONTR_SW_RESET BIT(2)
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#define LTR501_CONTR_PS_GAIN_MASK (BIT(3) | BIT(2))
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#define LTR501_CONTR_PS_GAIN_SHIFT 2
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#define LTR501_CONTR_ALS_GAIN_MASK BIT(3)
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#define LTR501_CONTR_ACTIVE BIT(1)
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#define LTR501_STATUS_ALS_RDY BIT(2)
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#define LTR501_STATUS_PS_RDY BIT(0)
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#define LTR501_PS_DATA_MASK 0x7ff
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struct ltr501_data {
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struct i2c_client *client;
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struct mutex lock_als, lock_ps;
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u8 als_contr, ps_contr;
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};
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static int ltr501_drdy(struct ltr501_data *data, u8 drdy_mask)
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{
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int tries = 100;
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int ret;
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while (tries--) {
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ret = i2c_smbus_read_byte_data(data->client,
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LTR501_ALS_PS_STATUS);
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if (ret < 0)
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return ret;
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if ((ret & drdy_mask) == drdy_mask)
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return 0;
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msleep(25);
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}
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dev_err(&data->client->dev, "ltr501_drdy() failed, data not ready\n");
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return -EIO;
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}
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static int ltr501_read_als(struct ltr501_data *data, __le16 buf[2])
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{
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int ret = ltr501_drdy(data, LTR501_STATUS_ALS_RDY);
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if (ret < 0)
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return ret;
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/* always read both ALS channels in given order */
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return i2c_smbus_read_i2c_block_data(data->client,
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LTR501_ALS_DATA1, 2 * sizeof(__le16), (u8 *) buf);
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}
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static int ltr501_read_ps(struct ltr501_data *data)
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{
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int ret = ltr501_drdy(data, LTR501_STATUS_PS_RDY);
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if (ret < 0)
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return ret;
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return i2c_smbus_read_word_data(data->client, LTR501_PS_DATA);
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}
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#define LTR501_INTENSITY_CHANNEL(_idx, _addr, _mod, _shared) { \
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.type = IIO_INTENSITY, \
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.modified = 1, \
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.address = (_addr), \
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.channel2 = (_mod), \
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.info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \
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.info_mask_shared_by_type = (_shared), \
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.scan_index = (_idx), \
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.scan_type = { \
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.sign = 'u', \
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.realbits = 16, \
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.storagebits = 16, \
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.endianness = IIO_CPU, \
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} \
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}
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static const struct iio_chan_spec ltr501_channels[] = {
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LTR501_INTENSITY_CHANNEL(0, LTR501_ALS_DATA0, IIO_MOD_LIGHT_BOTH, 0),
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LTR501_INTENSITY_CHANNEL(1, LTR501_ALS_DATA1, IIO_MOD_LIGHT_IR,
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BIT(IIO_CHAN_INFO_SCALE)),
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{
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.type = IIO_PROXIMITY,
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.address = LTR501_PS_DATA,
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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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.scan_index = 2,
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.scan_type = {
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.sign = 'u',
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.realbits = 11,
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.storagebits = 16,
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.endianness = IIO_CPU,
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},
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},
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IIO_CHAN_SOFT_TIMESTAMP(3),
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};
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static const int ltr501_ps_gain[4][2] = {
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{1, 0}, {0, 250000}, {0, 125000}, {0, 62500}
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};
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static int ltr501_read_raw(struct iio_dev *indio_dev,
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struct iio_chan_spec const *chan,
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int *val, int *val2, long mask)
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{
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struct ltr501_data *data = iio_priv(indio_dev);
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__le16 buf[2];
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int ret, i;
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switch (mask) {
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case IIO_CHAN_INFO_RAW:
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if (iio_buffer_enabled(indio_dev))
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return -EBUSY;
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switch (chan->type) {
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case IIO_INTENSITY:
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mutex_lock(&data->lock_als);
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ret = ltr501_read_als(data, buf);
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mutex_unlock(&data->lock_als);
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if (ret < 0)
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return ret;
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*val = le16_to_cpu(chan->address == LTR501_ALS_DATA1 ?
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buf[0] : buf[1]);
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return IIO_VAL_INT;
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case IIO_PROXIMITY:
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mutex_lock(&data->lock_ps);
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ret = ltr501_read_ps(data);
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mutex_unlock(&data->lock_ps);
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if (ret < 0)
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return ret;
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*val = ret & LTR501_PS_DATA_MASK;
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return IIO_VAL_INT;
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default:
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return -EINVAL;
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}
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case IIO_CHAN_INFO_SCALE:
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switch (chan->type) {
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case IIO_INTENSITY:
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if (data->als_contr & LTR501_CONTR_ALS_GAIN_MASK) {
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*val = 0;
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*val2 = 5000;
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return IIO_VAL_INT_PLUS_MICRO;
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} else {
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*val = 1;
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*val2 = 0;
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return IIO_VAL_INT;
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}
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case IIO_PROXIMITY:
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i = (data->ps_contr & LTR501_CONTR_PS_GAIN_MASK) >>
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LTR501_CONTR_PS_GAIN_SHIFT;
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*val = ltr501_ps_gain[i][0];
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*val2 = ltr501_ps_gain[i][1];
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return IIO_VAL_INT_PLUS_MICRO;
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default:
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return -EINVAL;
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}
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}
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return -EINVAL;
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}
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static int ltr501_get_ps_gain_index(int val, int val2)
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{
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int i;
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for (i = 0; i < ARRAY_SIZE(ltr501_ps_gain); i++)
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if (val == ltr501_ps_gain[i][0] && val2 == ltr501_ps_gain[i][1])
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return i;
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return -1;
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}
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static int ltr501_write_raw(struct iio_dev *indio_dev,
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struct iio_chan_spec const *chan,
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int val, int val2, long mask)
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{
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struct ltr501_data *data = iio_priv(indio_dev);
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int i;
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if (iio_buffer_enabled(indio_dev))
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return -EBUSY;
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switch (mask) {
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case IIO_CHAN_INFO_SCALE:
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switch (chan->type) {
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case IIO_INTENSITY:
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if (val == 0 && val2 == 5000)
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data->als_contr |= LTR501_CONTR_ALS_GAIN_MASK;
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else if (val == 1 && val2 == 0)
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data->als_contr &= ~LTR501_CONTR_ALS_GAIN_MASK;
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else
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return -EINVAL;
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return i2c_smbus_write_byte_data(data->client,
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LTR501_ALS_CONTR, data->als_contr);
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case IIO_PROXIMITY:
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i = ltr501_get_ps_gain_index(val, val2);
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if (i < 0)
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return -EINVAL;
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data->ps_contr &= ~LTR501_CONTR_PS_GAIN_MASK;
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data->ps_contr |= i << LTR501_CONTR_PS_GAIN_SHIFT;
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return i2c_smbus_write_byte_data(data->client,
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LTR501_PS_CONTR, data->ps_contr);
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default:
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return -EINVAL;
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}
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}
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return -EINVAL;
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}
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static IIO_CONST_ATTR(in_proximity_scale_available, "1 0.25 0.125 0.0625");
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static IIO_CONST_ATTR(in_intensity_scale_available, "1 0.005");
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static struct attribute *ltr501_attributes[] = {
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&iio_const_attr_in_proximity_scale_available.dev_attr.attr,
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&iio_const_attr_in_intensity_scale_available.dev_attr.attr,
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NULL
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};
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static const struct attribute_group ltr501_attribute_group = {
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.attrs = ltr501_attributes,
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};
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static const struct iio_info ltr501_info = {
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.read_raw = ltr501_read_raw,
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.write_raw = ltr501_write_raw,
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.attrs = <r501_attribute_group,
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.driver_module = THIS_MODULE,
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};
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static int ltr501_write_contr(struct i2c_client *client, u8 als_val, u8 ps_val)
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{
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int ret = i2c_smbus_write_byte_data(client, LTR501_ALS_CONTR, als_val);
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if (ret < 0)
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return ret;
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return i2c_smbus_write_byte_data(client, LTR501_PS_CONTR, ps_val);
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}
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static irqreturn_t ltr501_trigger_handler(int irq, void *p)
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{
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struct iio_poll_func *pf = p;
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struct iio_dev *indio_dev = pf->indio_dev;
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struct ltr501_data *data = iio_priv(indio_dev);
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u16 buf[8];
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__le16 als_buf[2];
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u8 mask = 0;
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int j = 0;
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int ret;
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memset(buf, 0, sizeof(buf));
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/* figure out which data needs to be ready */
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if (test_bit(0, indio_dev->active_scan_mask) ||
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test_bit(1, indio_dev->active_scan_mask))
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mask |= LTR501_STATUS_ALS_RDY;
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if (test_bit(2, indio_dev->active_scan_mask))
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mask |= LTR501_STATUS_PS_RDY;
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ret = ltr501_drdy(data, mask);
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if (ret < 0)
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goto done;
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if (mask & LTR501_STATUS_ALS_RDY) {
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ret = i2c_smbus_read_i2c_block_data(data->client,
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LTR501_ALS_DATA1, sizeof(als_buf), (u8 *) als_buf);
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if (ret < 0)
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return ret;
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if (test_bit(0, indio_dev->active_scan_mask))
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buf[j++] = le16_to_cpu(als_buf[1]);
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if (test_bit(1, indio_dev->active_scan_mask))
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buf[j++] = le16_to_cpu(als_buf[0]);
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}
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if (mask & LTR501_STATUS_PS_RDY) {
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ret = i2c_smbus_read_word_data(data->client, LTR501_PS_DATA);
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if (ret < 0)
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goto done;
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buf[j++] = ret & LTR501_PS_DATA_MASK;
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}
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iio_push_to_buffers_with_timestamp(indio_dev, buf,
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iio_get_time_ns());
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done:
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iio_trigger_notify_done(indio_dev->trig);
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return IRQ_HANDLED;
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}
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static int ltr501_init(struct ltr501_data *data)
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{
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int ret;
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ret = i2c_smbus_read_byte_data(data->client, LTR501_ALS_CONTR);
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if (ret < 0)
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return ret;
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data->als_contr = ret | LTR501_CONTR_ACTIVE;
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ret = i2c_smbus_read_byte_data(data->client, LTR501_PS_CONTR);
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if (ret < 0)
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return ret;
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data->ps_contr = ret | LTR501_CONTR_ACTIVE;
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return ltr501_write_contr(data->client, data->als_contr,
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data->ps_contr);
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}
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static int ltr501_probe(struct i2c_client *client,
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const struct i2c_device_id *id)
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{
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struct ltr501_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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mutex_init(&data->lock_als);
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mutex_init(&data->lock_ps);
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ret = i2c_smbus_read_byte_data(data->client, LTR501_PART_ID);
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if (ret < 0)
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return ret;
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if ((ret >> 4) != 0x8)
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return -ENODEV;
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indio_dev->dev.parent = &client->dev;
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indio_dev->info = <r501_info;
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indio_dev->channels = ltr501_channels;
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indio_dev->num_channels = ARRAY_SIZE(ltr501_channels);
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indio_dev->name = LTR501_DRV_NAME;
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indio_dev->modes = INDIO_DIRECT_MODE;
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ret = ltr501_init(data);
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if (ret < 0)
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return ret;
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ret = iio_triggered_buffer_setup(indio_dev, NULL,
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ltr501_trigger_handler, NULL);
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if (ret)
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return ret;
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ret = iio_device_register(indio_dev);
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if (ret)
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goto error_unreg_buffer;
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return 0;
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error_unreg_buffer:
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iio_triggered_buffer_cleanup(indio_dev);
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return ret;
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}
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static int ltr501_powerdown(struct ltr501_data *data)
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{
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return ltr501_write_contr(data->client,
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data->als_contr & ~LTR501_CONTR_ACTIVE,
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data->ps_contr & ~LTR501_CONTR_ACTIVE);
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}
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static int ltr501_remove(struct i2c_client *client)
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{
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struct iio_dev *indio_dev = i2c_get_clientdata(client);
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iio_device_unregister(indio_dev);
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iio_triggered_buffer_cleanup(indio_dev);
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ltr501_powerdown(iio_priv(indio_dev));
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return 0;
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}
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#ifdef CONFIG_PM_SLEEP
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static int ltr501_suspend(struct device *dev)
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{
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struct ltr501_data *data = iio_priv(i2c_get_clientdata(
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to_i2c_client(dev)));
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return ltr501_powerdown(data);
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}
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static int ltr501_resume(struct device *dev)
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{
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struct ltr501_data *data = iio_priv(i2c_get_clientdata(
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to_i2c_client(dev)));
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return ltr501_write_contr(data->client, data->als_contr,
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data->ps_contr);
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}
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#endif
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static SIMPLE_DEV_PM_OPS(ltr501_pm_ops, ltr501_suspend, ltr501_resume);
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static const struct i2c_device_id ltr501_id[] = {
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{ "ltr501", 0 },
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{ }
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};
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MODULE_DEVICE_TABLE(i2c, ltr501_id);
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static struct i2c_driver ltr501_driver = {
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.driver = {
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.name = LTR501_DRV_NAME,
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.pm = <r501_pm_ops,
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.owner = THIS_MODULE,
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},
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.probe = ltr501_probe,
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.remove = ltr501_remove,
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.id_table = ltr501_id,
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};
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module_i2c_driver(ltr501_driver);
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MODULE_AUTHOR("Peter Meerwald <pmeerw@pmeerw.net>");
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MODULE_DESCRIPTION("Lite-On LTR501 ambient light and proximity sensor driver");
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MODULE_LICENSE("GPL");
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