--- /dev/null
+// 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);
+ *val = value;
+ mutex_unlock(&sunrise->lock);
+
+ if (ret)
+ return ret;
+
+ return IIO_VAL_INT;
+
+ case IIO_TEMP:
+ mutex_lock(&sunrise->lock);
+ ret = sunrise_read_word(sunrise, SUNRISE_CHIP_TEMPERATURE_REG,
+ &value);
+ *val = value;
+ mutex_unlock(&sunrise->lock);
+
+ if (ret)
+ return ret;
+
+ 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_new = 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");
projects / platform / kernel / linux-rpi.git / commitdiff