// SPDX-License-Identifier: GPL-2.0 /* * sgp30.c - Support for Sensirion SGP Gas Sensors * * Copyright (C) 2018 Andreas Brauchli <[email protected]> * * I2C slave address: 0x58 * * Datasheets: * https://www.sensirion.com/file/datasheet_sgp30 * https://www.sensirion.com/file/datasheet_sgpc3 * * TODO: * - baseline support * - humidity compensation * - power mode switching (SGPC3) */ #include <linux/crc8.h> #include <linux/delay.h> #include <linux/kthread.h> #include <linux/module.h> #include <linux/mod_devicetable.h> #include <linux/mutex.h> #include <linux/i2c.h> #include <linux/iio/iio.h> #include <linux/iio/sysfs.h> #define SGP_WORD_LEN … #define SGP_CRC8_POLYNOMIAL … #define SGP_CRC8_INIT … #define SGP_CRC8_LEN … #define SGP_CMD(cmd_word) … #define SGP_CMD_DURATION_US … #define SGP_MEASUREMENT_DURATION_US … #define SGP_CMD_LEN … #define SGP_CMD_MAX_BUF_SIZE … #define SGP_MEASUREMENT_LEN … #define SGP30_MEASURE_INTERVAL_HZ … #define SGPC3_MEASURE_INTERVAL_HZ … #define SGP_VERS_PRODUCT(data) … #define SGP_VERS_RESERVED(data) … #define SGP_VERS_GEN(data) … #define SGP_VERS_ENG_BIT(data) … #define SGP_VERS_MAJOR(data) … #define SGP_VERS_MINOR(data) … DECLARE_CRC8_TABLE(sgp_crc8_table); enum sgp_product_id { … }; enum sgp30_channel_idx { … }; enum sgpc3_channel_idx { … }; enum sgp_cmd { … }; struct sgp_version { … }; struct sgp_crc_word { … } __attribute__((packed)); sgp_reading; enum _iaq_buffer_state { … }; struct sgp_data { … }; struct sgp_device { … }; static const struct sgp_version supported_versions_sgp30[] = …; static const struct sgp_version supported_versions_sgpc3[] = …; static const struct iio_chan_spec sgp30_channels[] = …; static const struct iio_chan_spec sgpc3_channels[] = …; static const struct sgp_device sgp_devices[] = …; /** * sgp_verify_buffer() - verify the checksums of the data buffer words * * @data: SGP data * @buf: Raw data buffer * @word_count: Num data words stored in the buffer, excluding CRC bytes * * Return: 0 on success, negative error otherwise. */ static int sgp_verify_buffer(const struct sgp_data *data, union sgp_reading *buf, size_t word_count) { … } /** * sgp_read_cmd() - reads data from sensor after issuing a command * The caller must hold data->data_lock for the duration of the call. * @data: SGP data * @cmd: SGP Command to issue * @buf: Raw data buffer to use * @word_count: Num words to read, excluding CRC bytes * @duration_us: Time taken to sensor to take a reading and data to be ready. * * Return: 0 on success, negative error otherwise. */ static int sgp_read_cmd(struct sgp_data *data, enum sgp_cmd cmd, union sgp_reading *buf, size_t word_count, unsigned long duration_us) { … } /** * sgp_measure_iaq() - measure and retrieve IAQ values from sensor * The caller must hold data->data_lock for the duration of the call. * @data: SGP data * * Return: 0 on success, -EBUSY on default values, negative error * otherwise. */ static int sgp_measure_iaq(struct sgp_data *data) { … } static void sgp_iaq_thread_sleep_until(const struct sgp_data *data, unsigned long sleep_jiffies) { … } static int sgp_iaq_threadfn(void *p) { … } static int sgp_read_raw(struct iio_dev *indio_dev, struct iio_chan_spec const *chan, int *val, int *val2, long mask) { … } static int sgp_check_compat(struct sgp_data *data, unsigned int product_id) { … } static void sgp_init(struct sgp_data *data) { … } static const struct iio_info sgp_info = …; static const struct of_device_id sgp_dt_ids[] = …; static int sgp_probe(struct i2c_client *client) { … } static void sgp_remove(struct i2c_client *client) { … } static const struct i2c_device_id sgp_id[] = …; MODULE_DEVICE_TABLE(i2c, sgp_id); MODULE_DEVICE_TABLE(of, sgp_dt_ids); static struct i2c_driver sgp_driver = …; module_i2c_driver(…) …; MODULE_AUTHOR(…) …; MODULE_AUTHOR(…) …; MODULE_DESCRIPTION(…) …; MODULE_LICENSE(…) …;
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