linux/drivers/iio/chemical/sunrise_co2.c

// 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 …

#define SUNRISE_ERROR_STATUS_REG …
#define SUNRISE_CO2_FILTERED_COMP_REG …
#define SUNRISE_CHIP_TEMPERATURE_REG …
#define SUNRISE_CALIBRATION_STATUS_REG …
#define SUNRISE_CALIBRATION_COMMAND_REG …
#define SUNRISE_CALIBRATION_FACTORY_CMD …
#define SUNRISE_CALIBRATION_BACKGROUND_CMD …
/*
 * The calibration timeout is not characterized in the datasheet.
 * Use 30 seconds as a reasonable upper limit.
 */
#define SUNRISE_CALIBRATION_TIMEOUT_US …

struct sunrise_dev { … };

/* 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)
{ … }

static int sunrise_regmap_write(void *context, const void *val_buf, size_t count)
{ … }

/*
 * 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)
{ … }

static int sunrise_read_word(struct sunrise_dev *sunrise, u8 reg, u16 *val)
{ … }

static int sunrise_write_byte(struct sunrise_dev *sunrise, u8 reg, u8 val)
{ … }

static int sunrise_write_word(struct sunrise_dev *sunrise, u8 reg, u16 data)
{ … }

/* Trigger a calibration cycle. */

enum { … };

static const struct sunrise_calib_data { … } calib_data[] = …;

static int sunrise_calibrate(struct sunrise_dev *sunrise,
			     const struct sunrise_calib_data *data)
{ … }

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)
{ … }

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)
{ … }

 /* Enumerate and retrieve the chip error status. */
enum { … };

static const char * const sunrise_error_statuses[] = …;

static const struct iio_enum sunrise_error_statuses_enum = …;

static ssize_t sunrise_error_status_read(struct iio_dev *iiodev,
					 uintptr_t private,
					 const struct iio_chan_spec *chan,
					 char *buf)
{ … }

static const struct iio_chan_spec_ext_info sunrise_concentration_ext_info[] = …;

static const struct iio_chan_spec sunrise_channels[] = …;

static int sunrise_read_raw(struct iio_dev *iio_dev,
			    const struct iio_chan_spec *chan,
			    int *val, int *val2, long mask)
{ … }

static const struct iio_info sunrise_info = …;

static const struct regmap_bus sunrise_regmap_bus = …;

static const struct regmap_config sunrise_regmap_config = …;

static int sunrise_probe(struct i2c_client *client)
{ … }

static const struct of_device_id sunrise_of_match[] = …;
MODULE_DEVICE_TABLE(of, sunrise_of_match);

static struct i2c_driver sunrise_driver = …;
module_i2c_driver(…) …;

MODULE_AUTHOR(…) …;
MODULE_DESCRIPTION(…) …;
MODULE_LICENSE(…) …;