diff options
Diffstat (limited to 'drivers/iio/proximity/rfd77402.c')
| -rw-r--r-- | drivers/iio/proximity/rfd77402.c | 330 |
1 files changed, 330 insertions, 0 deletions
diff --git a/drivers/iio/proximity/rfd77402.c b/drivers/iio/proximity/rfd77402.c new file mode 100644 index 000000000..cb80b3c9d --- /dev/null +++ b/drivers/iio/proximity/rfd77402.c @@ -0,0 +1,330 @@ +// 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 i2c_client *client, u8 state, u16 check) +{ + int ret; + + ret = i2c_smbus_write_byte_data(client, RFD77402_CMD_R, + state | RFD77402_CMD_VALID); + if (ret < 0) + return ret; + + usleep_range(10000, 20000); + + ret = i2c_smbus_read_word_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 i2c_client *client) +{ + int ret; + int tries = 10; + + ret = rfd77402_set_state(client, RFD77402_CMD_MCPU_ON, + RFD77402_STATUS_MCPU_ON); + if (ret < 0) + return ret; + + ret = i2c_smbus_write_byte_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(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(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(client, 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->client); + 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 i2c_client *client) +{ + int ret, i; + + ret = rfd77402_set_state(client, 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(client, RFD77402_ICSR, + RFD77402_ICSR_INT_MODE); + if (ret < 0) + return ret; + + /* I2C configuration */ + ret = i2c_smbus_write_word_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(client, RFD77402_PMU_CFG, 0x0500); + if (ret < 0) + return ret; + + ret = rfd77402_set_state(client, RFD77402_CMD_MCPU_OFF, + RFD77402_STATUS_MCPU_OFF); + if (ret < 0) + return ret; + + /* set initialization */ + ret = i2c_smbus_write_word_data(client, RFD77402_PMU_CFG, 0x0600); + if (ret < 0) + return ret; + + ret = rfd77402_set_state(client, 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(client, + rf77402_tof_config[i].reg, + rf77402_tof_config[i].val); + if (ret < 0) + return ret; + } + + ret = rfd77402_set_state(client, RFD77402_CMD_STANDBY, + RFD77402_STATUS_STANDBY); + + return ret; +} + +static int rfd77402_powerdown(struct i2c_client *client) +{ + return rfd77402_set_state(client, RFD77402_CMD_STANDBY, + RFD77402_STATUS_STANDBY); +} + +static void rfd77402_disable(void *client) +{ + rfd77402_powerdown(client); +} + +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); + data->client = client; + mutex_init(&data->lock); + + 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(client); + if (ret < 0) + return ret; + + ret = devm_add_action_or_reset(&client->dev, rfd77402_disable, client); + if (ret) + return ret; + + return devm_iio_device_register(&client->dev, indio_dev); +} + +static int rfd77402_suspend(struct device *dev) +{ + return rfd77402_powerdown(to_i2c_client(dev)); +} + +static int rfd77402_resume(struct device *dev) +{ + return rfd77402_init(to_i2c_client(dev)); +} + +static DEFINE_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 = pm_sleep_ptr(&rfd77402_pm_ops), + }, + .probe = rfd77402_probe, + .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"); |