/* * rfd77402.c - Support for RF Digital RFD77402 Time-of-Flight (distance) sensor * * Copyright 2017 Peter Meerwald-Stadler * * 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 #include #include #include #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 "); MODULE_DESCRIPTION("RFD77402 Time-of-Flight sensor driver"); MODULE_LICENSE("GPL");