![Peter Meerwald-Stadler](/assets/img/avatar_default.png)
Driver for RF Digital RFD77402 VCSEL (vertical-cavity surface-emitting laser) Time-of-Flight (ToF) sensor to measure distance up to 2 m with millimeter precision Signed-off-by: Peter Meerwald-Stadler <pmeerw@pmeerw.net> Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
353 lines
8.1 KiB
C
353 lines
8.1 KiB
C
/*
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* rfd77402.c - Support for RF Digital RFD77402 Time-of-Flight (distance) sensor
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*
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* Copyright 2017 Peter Meerwald-Stadler <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 0x4c
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*
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* TODO: interrupt
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* https://media.digikey.com/pdf/Data%20Sheets/RF%20Digital%20PDFs/RFD77402.pdf
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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/delay.h>
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#include <linux/iio/iio.h>
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#define RFD77402_DRV_NAME "rfd77402"
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#define RFD77402_ICSR 0x00 /* Interrupt Control Status Register */
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#define RFD77402_ICSR_INT_MODE BIT(2)
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#define RFD77402_ICSR_INT_POL BIT(3)
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#define RFD77402_ICSR_RESULT BIT(4)
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#define RFD77402_ICSR_M2H_MSG BIT(5)
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#define RFD77402_ICSR_H2M_MSG BIT(6)
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#define RFD77402_ICSR_RESET BIT(7)
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#define RFD77402_CMD_R 0x04
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#define RFD77402_CMD_SINGLE 0x01
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#define RFD77402_CMD_STANDBY 0x10
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#define RFD77402_CMD_MCPU_OFF 0x11
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#define RFD77402_CMD_MCPU_ON 0x12
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#define RFD77402_CMD_RESET BIT(6)
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#define RFD77402_CMD_VALID BIT(7)
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#define RFD77402_STATUS_R 0x06
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#define RFD77402_STATUS_PM_MASK GENMASK(4, 0)
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#define RFD77402_STATUS_STANDBY 0x00
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#define RFD77402_STATUS_MCPU_OFF 0x10
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#define RFD77402_STATUS_MCPU_ON 0x18
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#define RFD77402_RESULT_R 0x08
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#define RFD77402_RESULT_DIST_MASK GENMASK(12, 2)
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#define RFD77402_RESULT_ERR_MASK GENMASK(14, 13)
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#define RFD77402_RESULT_VALID BIT(15)
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#define RFD77402_PMU_CFG 0x14
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#define RFD77402_PMU_MCPU_INIT BIT(9)
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#define RFD77402_I2C_INIT_CFG 0x1c
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#define RFD77402_I2C_ADDR_INCR BIT(0)
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#define RFD77402_I2C_DATA_INCR BIT(2)
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#define RFD77402_I2C_HOST_DEBUG BIT(5)
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#define RFD77402_I2C_MCPU_DEBUG BIT(6)
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#define RFD77402_CMD_CFGR_A 0x0c
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#define RFD77402_CMD_CFGR_B 0x0e
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#define RFD77402_HFCFG_0 0x20
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#define RFD77402_HFCFG_1 0x22
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#define RFD77402_HFCFG_2 0x24
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#define RFD77402_HFCFG_3 0x26
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#define RFD77402_MOD_CHIP_ID 0x28
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/* magic configuration values from datasheet */
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static const struct {
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u8 reg;
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u16 val;
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} rf77402_tof_config[] = {
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{RFD77402_CMD_CFGR_A, 0xe100},
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{RFD77402_CMD_CFGR_B, 0x10ff},
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{RFD77402_HFCFG_0, 0x07d0},
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{RFD77402_HFCFG_1, 0x5008},
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{RFD77402_HFCFG_2, 0xa041},
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{RFD77402_HFCFG_3, 0x45d4},
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};
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struct rfd77402_data {
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struct i2c_client *client;
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/* Serialize reads from the sensor */
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struct mutex lock;
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};
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static const struct iio_chan_spec rfd77402_channels[] = {
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{
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.type = IIO_DISTANCE,
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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 int rfd77402_set_state(struct rfd77402_data *data, u8 state, u16 check)
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{
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int ret;
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ret = i2c_smbus_write_byte_data(data->client, RFD77402_CMD_R,
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state | RFD77402_CMD_VALID);
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if (ret < 0)
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return ret;
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usleep_range(10000, 20000);
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ret = i2c_smbus_read_word_data(data->client, RFD77402_STATUS_R);
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if (ret < 0)
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return ret;
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if ((ret & RFD77402_STATUS_PM_MASK) != check)
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return -ENODEV;
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return 0;
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}
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static int rfd77402_measure(struct rfd77402_data *data)
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{
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int ret;
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int tries = 10;
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ret = rfd77402_set_state(data, RFD77402_CMD_MCPU_ON,
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RFD77402_STATUS_MCPU_ON);
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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, RFD77402_CMD_R,
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RFD77402_CMD_SINGLE |
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RFD77402_CMD_VALID);
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if (ret < 0)
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goto err;
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while (tries-- > 0) {
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ret = i2c_smbus_read_byte_data(data->client, RFD77402_ICSR);
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if (ret < 0)
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goto err;
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if (ret & RFD77402_ICSR_RESULT)
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break;
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msleep(20);
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}
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if (tries < 0) {
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ret = -ETIMEDOUT;
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goto err;
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}
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ret = i2c_smbus_read_word_data(data->client, RFD77402_RESULT_R);
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if (ret < 0)
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goto err;
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if ((ret & RFD77402_RESULT_ERR_MASK) ||
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!(ret & RFD77402_RESULT_VALID)) {
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ret = -EIO;
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goto err;
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}
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return (ret & RFD77402_RESULT_DIST_MASK) >> 2;
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err:
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rfd77402_set_state(data, RFD77402_CMD_MCPU_OFF,
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RFD77402_STATUS_MCPU_OFF);
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return ret;
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}
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static int rfd77402_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 rfd77402_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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mutex_lock(&data->lock);
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ret = rfd77402_measure(data);
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mutex_unlock(&data->lock);
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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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/* 1 LSB is 1 mm */
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*val = 0;
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*val2 = 1000;
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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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static const struct iio_info rfd77402_info = {
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.read_raw = rfd77402_read_raw,
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};
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static int rfd77402_init(struct rfd77402_data *data)
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{
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int ret, i;
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ret = rfd77402_set_state(data, RFD77402_CMD_STANDBY,
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RFD77402_STATUS_STANDBY);
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if (ret < 0)
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return ret;
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/* configure INT pad as push-pull, active low */
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ret = i2c_smbus_write_byte_data(data->client, RFD77402_ICSR,
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RFD77402_ICSR_INT_MODE);
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if (ret < 0)
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return ret;
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/* I2C configuration */
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ret = i2c_smbus_write_word_data(data->client, RFD77402_I2C_INIT_CFG,
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RFD77402_I2C_ADDR_INCR |
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RFD77402_I2C_DATA_INCR |
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RFD77402_I2C_HOST_DEBUG |
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RFD77402_I2C_MCPU_DEBUG);
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if (ret < 0)
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return ret;
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/* set initialization */
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ret = i2c_smbus_write_word_data(data->client, RFD77402_PMU_CFG, 0x0500);
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if (ret < 0)
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return ret;
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ret = rfd77402_set_state(data, RFD77402_CMD_MCPU_OFF,
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RFD77402_STATUS_MCPU_OFF);
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if (ret < 0)
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return ret;
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/* set initialization */
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ret = i2c_smbus_write_word_data(data->client, RFD77402_PMU_CFG, 0x0600);
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if (ret < 0)
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return ret;
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ret = rfd77402_set_state(data, RFD77402_CMD_MCPU_ON,
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RFD77402_STATUS_MCPU_ON);
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if (ret < 0)
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return ret;
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for (i = 0; i < ARRAY_SIZE(rf77402_tof_config); i++) {
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ret = i2c_smbus_write_word_data(data->client,
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rf77402_tof_config[i].reg,
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rf77402_tof_config[i].val);
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if (ret < 0)
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return ret;
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}
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ret = rfd77402_set_state(data, RFD77402_CMD_STANDBY,
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RFD77402_STATUS_STANDBY);
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return ret;
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}
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static int rfd77402_powerdown(struct rfd77402_data *data)
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{
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return rfd77402_set_state(data, RFD77402_CMD_STANDBY,
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RFD77402_STATUS_STANDBY);
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}
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static int rfd77402_probe(struct i2c_client *client,
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const struct i2c_device_id *id)
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{
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struct rfd77402_data *data;
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struct iio_dev *indio_dev;
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int ret;
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ret = i2c_smbus_read_word_data(client, RFD77402_MOD_CHIP_ID);
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if (ret < 0)
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return ret;
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if (ret != 0xad01 && ret != 0xad02) /* known chip ids */
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return -ENODEV;
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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);
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indio_dev->dev.parent = &client->dev;
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indio_dev->info = &rfd77402_info;
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indio_dev->channels = rfd77402_channels;
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indio_dev->num_channels = ARRAY_SIZE(rfd77402_channels);
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indio_dev->name = RFD77402_DRV_NAME;
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indio_dev->modes = INDIO_DIRECT_MODE;
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ret = rfd77402_init(data);
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if (ret < 0)
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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 err_powerdown;
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return 0;
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err_powerdown:
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rfd77402_powerdown(data);
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return ret;
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}
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static int rfd77402_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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rfd77402_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 rfd77402_suspend(struct device *dev)
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{
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struct rfd77402_data *data = iio_priv(i2c_get_clientdata(
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to_i2c_client(dev)));
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return rfd77402_powerdown(data);
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}
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static int rfd77402_resume(struct device *dev)
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{
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struct rfd77402_data *data = iio_priv(i2c_get_clientdata(
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to_i2c_client(dev)));
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return rfd77402_init(data);
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}
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#endif
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static SIMPLE_DEV_PM_OPS(rfd77402_pm_ops, rfd77402_suspend, rfd77402_resume);
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static const struct i2c_device_id rfd77402_id[] = {
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{ "rfd77402", 0},
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{ }
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};
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MODULE_DEVICE_TABLE(i2c, rfd77402_id);
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static struct i2c_driver rfd77402_driver = {
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.driver = {
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.name = RFD77402_DRV_NAME,
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.pm = &rfd77402_pm_ops,
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},
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.probe = rfd77402_probe,
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.remove = rfd77402_remove,
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.id_table = rfd77402_id,
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};
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module_i2c_driver(rfd77402_driver);
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MODULE_AUTHOR("Peter Meerwald-Stadler <pmeerw@pmeerw.net>");
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MODULE_DESCRIPTION("RFD77402 Time-of-Flight sensor driver");
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MODULE_LICENSE("GPL");
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