| // SPDX-License-Identifier: GPL-2.0-only |
| /* |
| * rfd77402.c - Support for RF Digital RFD77402 Time-of-Flight (distance) sensor |
| * |
| * Copyright 2017 Peter Meerwald-Stadler <pmeerw@pmeerw.net> |
| * |
| * 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"); |