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/*
* rfd77402.c - Support for RF Digital RFD77402 Time-of-Flight (distance) sensor
*
* Copyright 2017 Peter Meerwald-Stadler <pmeerw@pmeerw.net>
*
* This file is subject to the terms and conditions of version 2 of
* the GNU General Public License. See the file COPYING in the main
* directory of this archive for more details.
*
* 7-bit I2C slave address 0x4c
*
* TODO: interrupt
* https://media.digikey.com/pdf/Data%20Sheets/RF%20Digital%20PDFs/RFD77402.pdf
*/
#include <linux/module.h>
#include <linux/i2c.h>
#include <linux/delay.h>
#include <linux/iio/iio.h>
#define RFD77402_DRV_NAME "rfd77402"
#define RFD77402_ICSR 0x00 /* Interrupt Control Status Register */
#define RFD77402_ICSR_INT_MODE BIT(2)
#define RFD77402_ICSR_INT_POL BIT(3)
#define RFD77402_ICSR_RESULT BIT(4)
#define RFD77402_ICSR_M2H_MSG BIT(5)
#define RFD77402_ICSR_H2M_MSG BIT(6)
#define RFD77402_ICSR_RESET BIT(7)
#define RFD77402_CMD_R 0x04
#define RFD77402_CMD_SINGLE 0x01
#define RFD77402_CMD_STANDBY 0x10
#define RFD77402_CMD_MCPU_OFF 0x11
#define RFD77402_CMD_MCPU_ON 0x12
#define RFD77402_CMD_RESET BIT(6)
#define RFD77402_CMD_VALID BIT(7)
#define RFD77402_STATUS_R 0x06
#define RFD77402_STATUS_PM_MASK GENMASK(4, 0)
#define RFD77402_STATUS_STANDBY 0x00
#define RFD77402_STATUS_MCPU_OFF 0x10
#define RFD77402_STATUS_MCPU_ON 0x18
#define RFD77402_RESULT_R 0x08
#define RFD77402_RESULT_DIST_MASK GENMASK(12, 2)
#define RFD77402_RESULT_ERR_MASK GENMASK(14, 13)
#define RFD77402_RESULT_VALID BIT(15)
#define RFD77402_PMU_CFG 0x14
#define RFD77402_PMU_MCPU_INIT BIT(9)
#define RFD77402_I2C_INIT_CFG 0x1c
#define RFD77402_I2C_ADDR_INCR BIT(0)
#define RFD77402_I2C_DATA_INCR BIT(2)
#define RFD77402_I2C_HOST_DEBUG BIT(5)
#define RFD77402_I2C_MCPU_DEBUG BIT(6)
#define RFD77402_CMD_CFGR_A 0x0c
#define RFD77402_CMD_CFGR_B 0x0e
#define RFD77402_HFCFG_0 0x20
#define RFD77402_HFCFG_1 0x22
#define RFD77402_HFCFG_2 0x24
#define RFD77402_HFCFG_3 0x26
#define RFD77402_MOD_CHIP_ID 0x28
/* magic configuration values from datasheet */
static const struct {
u8 reg;
u16 val;
} rf77402_tof_config[] = {
{RFD77402_CMD_CFGR_A, 0xe100},
{RFD77402_CMD_CFGR_B, 0x10ff},
{RFD77402_HFCFG_0, 0x07d0},
{RFD77402_HFCFG_1, 0x5008},
{RFD77402_HFCFG_2, 0xa041},
{RFD77402_HFCFG_3, 0x45d4},
};
struct rfd77402_data {
struct i2c_client *client;
/* Serialize reads from the sensor */
struct mutex lock;
};
static const struct iio_chan_spec rfd77402_channels[] = {
{
.type = IIO_DISTANCE,
.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
BIT(IIO_CHAN_INFO_SCALE),
},
};
static int rfd77402_set_state(struct rfd77402_data *data, u8 state, u16 check)
{
int ret;
ret = i2c_smbus_write_byte_data(data->client, RFD77402_CMD_R,
state | RFD77402_CMD_VALID);
if (ret < 0)
return ret;
usleep_range(10000, 20000);
ret = i2c_smbus_read_word_data(data->client, RFD77402_STATUS_R);
if (ret < 0)
return ret;
if ((ret & RFD77402_STATUS_PM_MASK) != check)
return -ENODEV;
return 0;
}
static int rfd77402_measure(struct rfd77402_data *data)
{
int ret;
int tries = 10;
ret = rfd77402_set_state(data, RFD77402_CMD_MCPU_ON,
RFD77402_STATUS_MCPU_ON);
if (ret < 0)
return ret;
ret = i2c_smbus_write_byte_data(data->client, RFD77402_CMD_R,
RFD77402_CMD_SINGLE |
RFD77402_CMD_VALID);
if (ret < 0)
goto err;
while (tries-- > 0) {
ret = i2c_smbus_read_byte_data(data->client, RFD77402_ICSR);
if (ret < 0)
goto err;
if (ret & RFD77402_ICSR_RESULT)
break;
msleep(20);
}
if (tries < 0) {
ret = -ETIMEDOUT;
goto err;
}
ret = i2c_smbus_read_word_data(data->client, RFD77402_RESULT_R);
if (ret < 0)
goto err;
if ((ret & RFD77402_RESULT_ERR_MASK) ||
!(ret & RFD77402_RESULT_VALID)) {
ret = -EIO;
goto err;
}
return (ret & RFD77402_RESULT_DIST_MASK) >> 2;
err:
rfd77402_set_state(data, RFD77402_CMD_MCPU_OFF,
RFD77402_STATUS_MCPU_OFF);
return ret;
}
static int rfd77402_read_raw(struct iio_dev *indio_dev,
struct iio_chan_spec const *chan,
int *val, int *val2, long mask)
{
struct rfd77402_data *data = iio_priv(indio_dev);
int ret;
switch (mask) {
case IIO_CHAN_INFO_RAW:
mutex_lock(&data->lock);
ret = rfd77402_measure(data);
mutex_unlock(&data->lock);
if (ret < 0)
return ret;
*val = ret;
return IIO_VAL_INT;
case IIO_CHAN_INFO_SCALE:
/* 1 LSB is 1 mm */
*val = 0;
*val2 = 1000;
return IIO_VAL_INT_PLUS_MICRO;
default:
return -EINVAL;
}
}
static const struct iio_info rfd77402_info = {
.read_raw = rfd77402_read_raw,
};
static int rfd77402_init(struct rfd77402_data *data)
{
int ret, i;
ret = rfd77402_set_state(data, RFD77402_CMD_STANDBY,
RFD77402_STATUS_STANDBY);
if (ret < 0)
return ret;
/* configure INT pad as push-pull, active low */
ret = i2c_smbus_write_byte_data(data->client, RFD77402_ICSR,
RFD77402_ICSR_INT_MODE);
if (ret < 0)
return ret;
/* I2C configuration */
ret = i2c_smbus_write_word_data(data->client, RFD77402_I2C_INIT_CFG,
RFD77402_I2C_ADDR_INCR |
RFD77402_I2C_DATA_INCR |
RFD77402_I2C_HOST_DEBUG |
RFD77402_I2C_MCPU_DEBUG);
if (ret < 0)
return ret;
/* set initialization */
ret = i2c_smbus_write_word_data(data->client, RFD77402_PMU_CFG, 0x0500);
if (ret < 0)
return ret;
ret = rfd77402_set_state(data, RFD77402_CMD_MCPU_OFF,
RFD77402_STATUS_MCPU_OFF);
if (ret < 0)
return ret;
/* set initialization */
ret = i2c_smbus_write_word_data(data->client, RFD77402_PMU_CFG, 0x0600);
if (ret < 0)
return ret;
ret = rfd77402_set_state(data, RFD77402_CMD_MCPU_ON,
RFD77402_STATUS_MCPU_ON);
if (ret < 0)
return ret;
for (i = 0; i < ARRAY_SIZE(rf77402_tof_config); i++) {
ret = i2c_smbus_write_word_data(data->client,
rf77402_tof_config[i].reg,
rf77402_tof_config[i].val);
if (ret < 0)
return ret;
}
ret = rfd77402_set_state(data, RFD77402_CMD_STANDBY,
RFD77402_STATUS_STANDBY);
return ret;
}
static int rfd77402_powerdown(struct rfd77402_data *data)
{
return rfd77402_set_state(data, RFD77402_CMD_STANDBY,
RFD77402_STATUS_STANDBY);
}
static int rfd77402_probe(struct i2c_client *client,
const struct i2c_device_id *id)
{
struct rfd77402_data *data;
struct iio_dev *indio_dev;
int ret;
ret = i2c_smbus_read_word_data(client, RFD77402_MOD_CHIP_ID);
if (ret < 0)
return ret;
if (ret != 0xad01 && ret != 0xad02) /* known chip ids */
return -ENODEV;
indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));
if (!indio_dev)
return -ENOMEM;
data = iio_priv(indio_dev);
i2c_set_clientdata(client, indio_dev);
data->client = client;
mutex_init(&data->lock);
indio_dev->dev.parent = &client->dev;
indio_dev->info = &rfd77402_info;
indio_dev->channels = rfd77402_channels;
indio_dev->num_channels = ARRAY_SIZE(rfd77402_channels);
indio_dev->name = RFD77402_DRV_NAME;
indio_dev->modes = INDIO_DIRECT_MODE;
ret = rfd77402_init(data);
if (ret < 0)
return ret;
ret = iio_device_register(indio_dev);
if (ret)
goto err_powerdown;
return 0;
err_powerdown:
rfd77402_powerdown(data);
return ret;
}
static int rfd77402_remove(struct i2c_client *client)
{
struct iio_dev *indio_dev = i2c_get_clientdata(client);
iio_device_unregister(indio_dev);
rfd77402_powerdown(iio_priv(indio_dev));
return 0;
}
#ifdef CONFIG_PM_SLEEP
static int rfd77402_suspend(struct device *dev)
{
struct rfd77402_data *data = iio_priv(i2c_get_clientdata(
to_i2c_client(dev)));
return rfd77402_powerdown(data);
}
static int rfd77402_resume(struct device *dev)
{
struct rfd77402_data *data = iio_priv(i2c_get_clientdata(
to_i2c_client(dev)));
return rfd77402_init(data);
}
#endif
static SIMPLE_DEV_PM_OPS(rfd77402_pm_ops, rfd77402_suspend, rfd77402_resume);
static const struct i2c_device_id rfd77402_id[] = {
{ "rfd77402", 0},
{ }
};
MODULE_DEVICE_TABLE(i2c, rfd77402_id);
static struct i2c_driver rfd77402_driver = {
.driver = {
.name = RFD77402_DRV_NAME,
.pm = &rfd77402_pm_ops,
},
.probe = rfd77402_probe,
.remove = rfd77402_remove,
.id_table = rfd77402_id,
};
module_i2c_driver(rfd77402_driver);
MODULE_AUTHOR("Peter Meerwald-Stadler <pmeerw@pmeerw.net>");
MODULE_DESCRIPTION("RFD77402 Time-of-Flight sensor driver");
MODULE_LICENSE("GPL");
|
