diff options
Diffstat (limited to 'drivers/iio/chemical/sunrise_co2.c')
| -rw-r--r-- | drivers/iio/chemical/sunrise_co2.c | 537 |
1 files changed, 537 insertions, 0 deletions
diff --git a/drivers/iio/chemical/sunrise_co2.c b/drivers/iio/chemical/sunrise_co2.c new file mode 100644 index 0000000000..cdb8696a4e --- /dev/null +++ b/drivers/iio/chemical/sunrise_co2.c @@ -0,0 +1,537 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Senseair Sunrise 006-0-0007 CO2 sensor driver. + * + * Copyright (C) 2021 Jacopo Mondi + * + * List of features not yet supported by the driver: + * - controllable EN pin + * - single-shot operations using the nDRY pin. + * - ABC/target calibration + */ + +#include <linux/bitops.h> +#include <linux/i2c.h> +#include <linux/kernel.h> +#include <linux/mod_devicetable.h> +#include <linux/module.h> +#include <linux/mutex.h> +#include <linux/regmap.h> +#include <linux/time64.h> + +#include <linux/iio/iio.h> + +#define DRIVER_NAME "sunrise_co2" + +#define SUNRISE_ERROR_STATUS_REG 0x00 +#define SUNRISE_CO2_FILTERED_COMP_REG 0x06 +#define SUNRISE_CHIP_TEMPERATURE_REG 0x08 +#define SUNRISE_CALIBRATION_STATUS_REG 0x81 +#define SUNRISE_CALIBRATION_COMMAND_REG 0x82 +#define SUNRISE_CALIBRATION_FACTORY_CMD 0x7c02 +#define SUNRISE_CALIBRATION_BACKGROUND_CMD 0x7c06 +/* + * The calibration timeout is not characterized in the datasheet. + * Use 30 seconds as a reasonable upper limit. + */ +#define SUNRISE_CALIBRATION_TIMEOUT_US (30 * USEC_PER_SEC) + +struct sunrise_dev { + struct i2c_client *client; + struct regmap *regmap; + /* Protects access to IIO attributes. */ + struct mutex lock; + bool ignore_nak; +}; + +/* Custom regmap read/write operations: perform unlocked access to the i2c bus. */ + +static int sunrise_regmap_read(void *context, const void *reg_buf, + size_t reg_size, void *val_buf, size_t val_size) +{ + struct i2c_client *client = context; + struct sunrise_dev *sunrise = i2c_get_clientdata(client); + union i2c_smbus_data data; + int ret; + + if (reg_size != 1 || !val_size) + return -EINVAL; + + memset(&data, 0, sizeof(data)); + data.block[0] = val_size; + + /* + * Wake up sensor by sending sensor address: START, sensor address, + * STOP. Sensor will not ACK this byte. + * + * The chip enters a low power state after 15ms without + * communications or after a complete read/write sequence. + */ + __i2c_smbus_xfer(client->adapter, client->addr, + sunrise->ignore_nak ? I2C_M_IGNORE_NAK : 0, + I2C_SMBUS_WRITE, 0, I2C_SMBUS_BYTE_DATA, &data); + + usleep_range(500, 1500); + + ret = __i2c_smbus_xfer(client->adapter, client->addr, client->flags, + I2C_SMBUS_READ, ((u8 *)reg_buf)[0], + I2C_SMBUS_I2C_BLOCK_DATA, &data); + if (ret < 0) + return ret; + + memcpy(val_buf, &data.block[1], data.block[0]); + + return 0; +} + +static int sunrise_regmap_write(void *context, const void *val_buf, size_t count) +{ + struct i2c_client *client = context; + struct sunrise_dev *sunrise = i2c_get_clientdata(client); + union i2c_smbus_data data; + + /* Discard reg address from values count. */ + if (!count) + return -EINVAL; + count--; + + memset(&data, 0, sizeof(data)); + data.block[0] = count; + memcpy(&data.block[1], (u8 *)val_buf + 1, count); + + __i2c_smbus_xfer(client->adapter, client->addr, + sunrise->ignore_nak ? I2C_M_IGNORE_NAK : 0, + I2C_SMBUS_WRITE, 0, I2C_SMBUS_BYTE_DATA, &data); + + usleep_range(500, 1500); + + return __i2c_smbus_xfer(client->adapter, client->addr, client->flags, + I2C_SMBUS_WRITE, ((u8 *)val_buf)[0], + I2C_SMBUS_I2C_BLOCK_DATA, &data); +} + +/* + * Sunrise i2c read/write operations: lock the i2c segment to avoid losing the + * wake up session. Use custom regmap operations that perform unlocked access to + * the i2c bus. + */ +static int sunrise_read_byte(struct sunrise_dev *sunrise, u8 reg) +{ + const struct i2c_client *client = sunrise->client; + const struct device *dev = &client->dev; + unsigned int val; + int ret; + + i2c_lock_bus(client->adapter, I2C_LOCK_SEGMENT); + ret = regmap_read(sunrise->regmap, reg, &val); + i2c_unlock_bus(client->adapter, I2C_LOCK_SEGMENT); + if (ret) { + dev_err(dev, "Read byte failed: reg 0x%02x (%d)\n", reg, ret); + return ret; + } + + return val; +} + +static int sunrise_read_word(struct sunrise_dev *sunrise, u8 reg, u16 *val) +{ + const struct i2c_client *client = sunrise->client; + const struct device *dev = &client->dev; + __be16 be_val; + int ret; + + i2c_lock_bus(client->adapter, I2C_LOCK_SEGMENT); + ret = regmap_bulk_read(sunrise->regmap, reg, &be_val, sizeof(be_val)); + i2c_unlock_bus(client->adapter, I2C_LOCK_SEGMENT); + if (ret) { + dev_err(dev, "Read word failed: reg 0x%02x (%d)\n", reg, ret); + return ret; + } + + *val = be16_to_cpu(be_val); + + return 0; +} + +static int sunrise_write_byte(struct sunrise_dev *sunrise, u8 reg, u8 val) +{ + const struct i2c_client *client = sunrise->client; + const struct device *dev = &client->dev; + int ret; + + i2c_lock_bus(client->adapter, I2C_LOCK_SEGMENT); + ret = regmap_write(sunrise->regmap, reg, val); + i2c_unlock_bus(client->adapter, I2C_LOCK_SEGMENT); + if (ret) + dev_err(dev, "Write byte failed: reg 0x%02x (%d)\n", reg, ret); + + return ret; +} + +static int sunrise_write_word(struct sunrise_dev *sunrise, u8 reg, u16 data) +{ + const struct i2c_client *client = sunrise->client; + const struct device *dev = &client->dev; + __be16 be_data = cpu_to_be16(data); + int ret; + + i2c_lock_bus(client->adapter, I2C_LOCK_SEGMENT); + ret = regmap_bulk_write(sunrise->regmap, reg, &be_data, sizeof(be_data)); + i2c_unlock_bus(client->adapter, I2C_LOCK_SEGMENT); + if (ret) + dev_err(dev, "Write word failed: reg 0x%02x (%d)\n", reg, ret); + + return ret; +} + +/* Trigger a calibration cycle. */ + +enum { + SUNRISE_CALIBRATION_FACTORY, + SUNRISE_CALIBRATION_BACKGROUND, +}; + +static const struct sunrise_calib_data { + u16 cmd; + u8 bit; + const char * const name; +} calib_data[] = { + [SUNRISE_CALIBRATION_FACTORY] = { + SUNRISE_CALIBRATION_FACTORY_CMD, + BIT(2), + "factory_calibration", + }, + [SUNRISE_CALIBRATION_BACKGROUND] = { + SUNRISE_CALIBRATION_BACKGROUND_CMD, + BIT(5), + "background_calibration", + }, +}; + +static int sunrise_calibrate(struct sunrise_dev *sunrise, + const struct sunrise_calib_data *data) +{ + unsigned int status; + int ret; + + /* Reset the calibration status reg. */ + ret = sunrise_write_byte(sunrise, SUNRISE_CALIBRATION_STATUS_REG, 0x00); + if (ret) + return ret; + + /* Write a calibration command and poll the calibration status bit. */ + ret = sunrise_write_word(sunrise, SUNRISE_CALIBRATION_COMMAND_REG, data->cmd); + if (ret) + return ret; + + dev_dbg(&sunrise->client->dev, "%s in progress\n", data->name); + + /* + * Calibration takes several seconds, so the sleep time between reads + * can be pretty relaxed. + */ + return read_poll_timeout(sunrise_read_byte, status, status & data->bit, + 200000, SUNRISE_CALIBRATION_TIMEOUT_US, false, + sunrise, SUNRISE_CALIBRATION_STATUS_REG); +} + +static ssize_t sunrise_cal_factory_write(struct iio_dev *iiodev, + uintptr_t private, + const struct iio_chan_spec *chan, + const char *buf, size_t len) +{ + struct sunrise_dev *sunrise = iio_priv(iiodev); + bool enable; + int ret; + + ret = kstrtobool(buf, &enable); + if (ret) + return ret; + + if (!enable) + return len; + + mutex_lock(&sunrise->lock); + ret = sunrise_calibrate(sunrise, &calib_data[SUNRISE_CALIBRATION_FACTORY]); + mutex_unlock(&sunrise->lock); + if (ret) + return ret; + + return len; +} + +static ssize_t sunrise_cal_background_write(struct iio_dev *iiodev, + uintptr_t private, + const struct iio_chan_spec *chan, + const char *buf, size_t len) +{ + struct sunrise_dev *sunrise = iio_priv(iiodev); + bool enable; + int ret; + + ret = kstrtobool(buf, &enable); + if (ret) + return ret; + + if (!enable) + return len; + + mutex_lock(&sunrise->lock); + ret = sunrise_calibrate(sunrise, &calib_data[SUNRISE_CALIBRATION_BACKGROUND]); + mutex_unlock(&sunrise->lock); + if (ret) + return ret; + + return len; +} + + /* Enumerate and retrieve the chip error status. */ +enum { + SUNRISE_ERROR_FATAL, + SUNRISE_ERROR_I2C, + SUNRISE_ERROR_ALGORITHM, + SUNRISE_ERROR_CALIBRATION, + SUNRISE_ERROR_SELF_DIAGNOSTIC, + SUNRISE_ERROR_OUT_OF_RANGE, + SUNRISE_ERROR_MEMORY, + SUNRISE_ERROR_NO_MEASUREMENT, + SUNRISE_ERROR_LOW_VOLTAGE, + SUNRISE_ERROR_MEASUREMENT_TIMEOUT, +}; + +static const char * const sunrise_error_statuses[] = { + [SUNRISE_ERROR_FATAL] = "error_fatal", + [SUNRISE_ERROR_I2C] = "error_i2c", + [SUNRISE_ERROR_ALGORITHM] = "error_algorithm", + [SUNRISE_ERROR_CALIBRATION] = "error_calibration", + [SUNRISE_ERROR_SELF_DIAGNOSTIC] = "error_self_diagnostic", + [SUNRISE_ERROR_OUT_OF_RANGE] = "error_out_of_range", + [SUNRISE_ERROR_MEMORY] = "error_memory", + [SUNRISE_ERROR_NO_MEASUREMENT] = "error_no_measurement", + [SUNRISE_ERROR_LOW_VOLTAGE] = "error_low_voltage", + [SUNRISE_ERROR_MEASUREMENT_TIMEOUT] = "error_measurement_timeout", +}; + +static const struct iio_enum sunrise_error_statuses_enum = { + .items = sunrise_error_statuses, + .num_items = ARRAY_SIZE(sunrise_error_statuses), +}; + +static ssize_t sunrise_error_status_read(struct iio_dev *iiodev, + uintptr_t private, + const struct iio_chan_spec *chan, + char *buf) +{ + struct sunrise_dev *sunrise = iio_priv(iiodev); + unsigned long errors; + ssize_t len = 0; + u16 value; + int ret; + u8 i; + + mutex_lock(&sunrise->lock); + ret = sunrise_read_word(sunrise, SUNRISE_ERROR_STATUS_REG, &value); + if (ret) { + mutex_unlock(&sunrise->lock); + return ret; + } + + errors = value; + for_each_set_bit(i, &errors, ARRAY_SIZE(sunrise_error_statuses)) + len += sysfs_emit_at(buf, len, "%s ", sunrise_error_statuses[i]); + + if (len) + buf[len - 1] = '\n'; + + mutex_unlock(&sunrise->lock); + + return len; +} + +static const struct iio_chan_spec_ext_info sunrise_concentration_ext_info[] = { + /* Calibration triggers. */ + { + .name = "calibration_factory", + .write = sunrise_cal_factory_write, + .shared = IIO_SEPARATE, + }, + { + .name = "calibration_background", + .write = sunrise_cal_background_write, + .shared = IIO_SEPARATE, + }, + + /* Error statuses. */ + { + .name = "error_status", + .read = sunrise_error_status_read, + .shared = IIO_SHARED_BY_ALL, + }, + { + .name = "error_status_available", + .shared = IIO_SHARED_BY_ALL, + .read = iio_enum_available_read, + .private = (uintptr_t)&sunrise_error_statuses_enum, + }, + {} +}; + +static const struct iio_chan_spec sunrise_channels[] = { + { + .type = IIO_CONCENTRATION, + .modified = 1, + .channel2 = IIO_MOD_CO2, + .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | + BIT(IIO_CHAN_INFO_SCALE), + .ext_info = sunrise_concentration_ext_info, + }, + { + .type = IIO_TEMP, + .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | + BIT(IIO_CHAN_INFO_SCALE), + }, +}; + +static int sunrise_read_raw(struct iio_dev *iio_dev, + const struct iio_chan_spec *chan, + int *val, int *val2, long mask) +{ + struct sunrise_dev *sunrise = iio_priv(iio_dev); + u16 value; + int ret; + + switch (mask) { + case IIO_CHAN_INFO_RAW: + switch (chan->type) { + case IIO_CONCENTRATION: + mutex_lock(&sunrise->lock); + ret = sunrise_read_word(sunrise, SUNRISE_CO2_FILTERED_COMP_REG, + &value); + mutex_unlock(&sunrise->lock); + + if (ret) + return ret; + + *val = value; + return IIO_VAL_INT; + + case IIO_TEMP: + mutex_lock(&sunrise->lock); + ret = sunrise_read_word(sunrise, SUNRISE_CHIP_TEMPERATURE_REG, + &value); + mutex_unlock(&sunrise->lock); + + if (ret) + return ret; + + *val = value; + return IIO_VAL_INT; + + default: + return -EINVAL; + } + + case IIO_CHAN_INFO_SCALE: + switch (chan->type) { + case IIO_CONCENTRATION: + /* + * 1 / 10^4 to comply with IIO scale for CO2 + * (percentage). The chip CO2 reading range is [400 - + * 5000] ppm which corresponds to [0,004 - 0,5] %. + */ + *val = 1; + *val2 = 10000; + return IIO_VAL_FRACTIONAL; + + case IIO_TEMP: + /* x10 to comply with IIO scale (millidegrees celsius). */ + *val = 10; + return IIO_VAL_INT; + + default: + return -EINVAL; + } + + default: + return -EINVAL; + } +} + +static const struct iio_info sunrise_info = { + .read_raw = sunrise_read_raw, +}; + +static const struct regmap_bus sunrise_regmap_bus = { + .read = sunrise_regmap_read, + .write = sunrise_regmap_write, +}; + +static const struct regmap_config sunrise_regmap_config = { + .reg_bits = 8, + .val_bits = 8, +}; + +static int sunrise_probe(struct i2c_client *client) +{ + struct sunrise_dev *sunrise; + struct iio_dev *iio_dev; + + if (!i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_BYTE_DATA | + I2C_FUNC_SMBUS_BLOCK_DATA)) { + dev_err(&client->dev, + "Adapter does not support required functionalities\n"); + return -EOPNOTSUPP; + } + + iio_dev = devm_iio_device_alloc(&client->dev, sizeof(*sunrise)); + if (!iio_dev) + return -ENOMEM; + + sunrise = iio_priv(iio_dev); + sunrise->client = client; + mutex_init(&sunrise->lock); + + i2c_set_clientdata(client, sunrise); + + sunrise->regmap = devm_regmap_init(&client->dev, &sunrise_regmap_bus, + client, &sunrise_regmap_config); + if (IS_ERR(sunrise->regmap)) { + dev_err(&client->dev, "Failed to initialize regmap\n"); + return PTR_ERR(sunrise->regmap); + } + + /* + * The chip nacks the wake up message. If the adapter does not support + * protocol mangling do not set the I2C_M_IGNORE_NAK flag at the expense + * of possible cruft in the logs. + */ + if (i2c_check_functionality(client->adapter, I2C_FUNC_PROTOCOL_MANGLING)) + sunrise->ignore_nak = true; + + iio_dev->info = &sunrise_info; + iio_dev->name = DRIVER_NAME; + iio_dev->channels = sunrise_channels; + iio_dev->num_channels = ARRAY_SIZE(sunrise_channels); + iio_dev->modes = INDIO_DIRECT_MODE; + + return devm_iio_device_register(&client->dev, iio_dev); +} + +static const struct of_device_id sunrise_of_match[] = { + { .compatible = "senseair,sunrise-006-0-0007" }, + {} +}; +MODULE_DEVICE_TABLE(of, sunrise_of_match); + +static struct i2c_driver sunrise_driver = { + .driver = { + .name = DRIVER_NAME, + .of_match_table = sunrise_of_match, + }, + .probe = sunrise_probe, +}; +module_i2c_driver(sunrise_driver); + +MODULE_AUTHOR("Jacopo Mondi <jacopo@jmondi.org>"); +MODULE_DESCRIPTION("Senseair Sunrise 006-0-0007 CO2 sensor IIO driver"); +MODULE_LICENSE("GPL v2"); |