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RIOT/drivers/sps30/sps30.c
Marian Buschsieweke f022f88629
drivers/sps30: make cppcheck happy
2022-01-05 15:09:10 +01:00

301 lines
11 KiB
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/*
* Copyright (C) 2020 Michel Rottleuthner
*
* This file is subject to the terms and conditions of the GNU Lesser
* General Public License v2.1. See the file LICENSE in the top level
* directory for more details.
*/
/**
* @ingroup drivers_sps30
* @brief Device driver for the Sensirion SPS30 particulate matter sensor
* @author Michel Rottleuthner <michel.rottleuthner@haw-hamburg.de>
* @file
*/
#define LOG_LEVEL LOG_DEBUG
#include "log.h"
#include <assert.h>
#include <errno.h>
#include <string.h>
#include "checksum/crc8.h"
#include "sps30.h"
#include "byteorder.h"
#include "kernel_defines.h"
/**
* @name SPS30 literal definitions
* @{
*/
#define SPS30_I2C_ADDR (0x69) /**< Fixed I2C address for the Sensor */
#define SPS30_CRC_POLY (0x31) /**< Polynomial for the CRC calculation */
#define SPS30_CRC_INIT (0xFF) /**< Init value for the CRC calculation */
#define SPS30_MESAURE_MODE (0x03) /**< Fixed mode byte for start cmd */
#define SPS30_DUMMY_BYTE (0x00) /**< Fixed dummy byte for unused bytes */
#define SPS30_PTR_LEN (2) /**< Pointer address length in bytes */
/** @} */
/**
* @name Address pointer values for all SPS30 I2C commands
* @{
*/
typedef enum {
SPS30_CMD_START_MEASURE = 0x0010, /**< Start measurement mode */
SPS30_CMD_STOP_MEASURE = 0x0104, /**< Stop measurement mode */
SPS30_CMD_RD_DATA_READY = 0x0202, /**< Read data-ready flag */
SPS30_CMD_RD_MEASUREMENTS = 0x0300, /**< Read measured values */
SPS30_CMD_RW_AUTOCLEAN = 0x8004, /**< Read/write autoclean interval */
SPS30_CMD_START_FAN_CLEAN = 0x5607, /**< Start fan cleaning */
SPS30_CMD_RD_ARTICLE = 0xD025, /**< Read article code */
SPS30_CMD_RD_SERIAL = 0xD033, /**< Read serial number */
SPS30_CMD_RESET = 0xD304, /**< Reset */
SPS30_CMD_SLEEP = 0x1001, /**< Sleep */
SPS30_CMD_WAKE_UP = 0x1103 /**< Wake-up */
} sps30_cmd_t;
/** @} */
/**
* @brief Combine payload and CRC into an SDS30 I2C data frame.
*
* @details The CRC for `data` is calculated and written to `crcd_data`
* together with the payload itself.
* The format of `data` must be just the pure payload:
* { data[0], data[1], data[2], ..., data[n]}
* The format of `crcd_data` same as it shall be sent to the SPS30.
* It consists of payload byte-pairs followed by a single CRC byte:
* { data[0], data[1], csum[0],.., data[n-1], data[n], csum[n-1] }
*
* @param[in] data Source buffer containing just the raw payload
* @param[in] len Size of the 'data' buffer
* @param[out] crcd_data Destination buffer for combined payload and CRCs
*
* @pre sizeof(crcd_data) must be equal to 1.5 * len
*
*/
static inline void _cpy_add_crc(uint8_t *data, size_t len, uint8_t *crcd_data)
{
for (size_t elem = 0; elem < len / 2; elem++) {
int idx = (elem << 1);
crcd_data[idx + elem] = data[idx];
crcd_data[idx + elem + 1] = data[idx + 1];
crcd_data[idx + elem + 2] = crc8(&data[idx], 2, SPS30_CRC_POLY,
SPS30_CRC_INIT);
}
}
/**
* @brief Check the CRC of an SDS30 I2C data frame.
*
* @details The CRC contained in the `crcd_data` is checked and the payload is
* copied to `data`.
* The format of `data` will be just the pure payload:
* { data[0], data[1], data[2], ..., data[n]}
* The format of `crcd_data` is same as it is read from the SPS30.
* It consists of payload byte-pairs followed by a single CRC byte:
* { data[0], data[1], csum[0],.., data[n-1], data[n], csum[n-1] }
*
* @pre sizeof(crcd_data) must be equal to 1.5 * len
*
* @param[out] data Destination buffer for just the raw payload
* @param[in] len Size of the 'data' buffer
* @param[in] crcd_data Source buffer containing combined payload and CRCs
*
* @return true if all CRCs are valid
* @return false if at least one CRC is invalid
*/
static inline bool _cpy_check_crc(uint8_t *data, size_t len, const uint8_t *crcd_data)
{
for (size_t elem = 0; elem < len / 2; elem++) {
int idx = (elem << 1);
data[idx] = crcd_data[idx + elem];
data[idx + 1] = crcd_data[idx + elem + 1];
if (crc8(&data[idx], 2, SPS30_CRC_POLY, SPS30_CRC_INIT) !=
(crcd_data[idx + elem + 2])) {
return false;
}
}
return true;
}
/**
* @brief Communicates with an SPS30 device by reading or writing data.
*
* @details This performs all three data transfer types supported by SPS30.
* (1) `Set Pointer`: writes a 16 bit pointer address to the device
* (2) `Set Pointer & Read Data`: (1) followed by separate data-read
* (3) `Set Pointer & Write Data`: (1) combined with a data-write
*
* @param[in] dev Pointer to SPS30 device handle
* @param[in] ptr_addr 16 bit pointer address used as command
* @param[in/out] data Pre-allocated memory pointing to either the data
* that will be sent to the device or to memory that
* will hold the response. For type (1) transfers
* this parameter will be ignored.
* @param[in] len Length of `data` buffer, set to 0 for type (1)
* @param[in] read set to true for reading or false for writing
*
* @return SPS30_OK if everything went fine
* @return -SPS30_CRC_ERROR if the CRC check failed
* @return -SPS30_I2C_ERROR if the I2C communication failed
*/
static int _rx_tx_data(const sps30_t *dev, uint16_t ptr_addr,
uint8_t *data, size_t len, bool read)
{
int res = 0;
unsigned retr = CONFIG_SPS30_ERROR_RETRY;
i2c_acquire(dev->p.i2c_dev);
do {
size_t addr_data_crc_len = SPS30_PTR_LEN + len + len / 2;
uint8_t frame_data[addr_data_crc_len];
frame_data[0] = ptr_addr >> 8;
frame_data[1] = ptr_addr & 0xFF;
/* Both transfer types, `Set Pointer` and `Set Pointer & Read Data`
require writing a pointer address to the device in a separate write
transaction */
if (len == 0 || read) {
res = i2c_write_bytes(dev->p.i2c_dev, SPS30_I2C_ADDR,
&frame_data[0], SPS30_PTR_LEN, 0);
}
if (res == 0 && read) {
/* The `Set Pointer & Read Data` transfer type requires a separate
read transaction to actually read the data */
res = i2c_read_bytes(dev->p.i2c_dev, SPS30_I2C_ADDR,
&frame_data[SPS30_PTR_LEN],
addr_data_crc_len - SPS30_PTR_LEN, 0);
if (!_cpy_check_crc(data, len, &frame_data[SPS30_PTR_LEN])) {
res = -SPS30_CRC_ERROR;
}
} else {
/* For the `Set Pointer & Write Data` transfer type the full frame
is transmitted as one single chunk */
_cpy_add_crc(data, len, &frame_data[SPS30_PTR_LEN]);
res = i2c_write_bytes(dev->p.i2c_dev, SPS30_I2C_ADDR,
&frame_data[0], addr_data_crc_len, 0);
}
} while (res != 0 && retr--);
i2c_release(dev->p.i2c_dev);
return res == 0 ? SPS30_OK : -SPS30_I2C_ERROR;
}
int sps30_init(sps30_t *dev, const sps30_params_t *params)
{
assert(dev && params);
dev->p = *params;
return sps30_start_measurement(dev);
}
int sps30_start_measurement(const sps30_t *dev)
{
assert(dev);
uint8_t data[] = {SPS30_MESAURE_MODE, SPS30_DUMMY_BYTE};
return _rx_tx_data(dev, SPS30_CMD_START_MEASURE, (uint8_t*)data,
sizeof(data), false);
}
int sps30_stop_measurement(const sps30_t *dev)
{
assert(dev);
return _rx_tx_data(dev, SPS30_CMD_STOP_MEASURE, NULL, 0, false);
}
bool sps30_data_ready(const sps30_t *dev, int *error)
{
assert(dev);
uint8_t data[2];
int res = _rx_tx_data(dev, SPS30_CMD_RD_DATA_READY, data, sizeof(data),
true);
if (*error) {
*error = res;
}
return (res == SPS30_OK) && data[1];
}
int sps30_read_measurement(const sps30_t *dev, sps30_data_t *data)
{
/* This compile time check is needed to ensure the below method used for
endianness conversion will work as expected */
static_assert(sizeof(sps30_data_t) == (sizeof(float) * 10),
"sps30_data_t must be sized 10 floats");
assert(dev && data);
/* The target buffer is also used for storing the raw data temporarily */
int res = _rx_tx_data(dev, SPS30_CMD_RD_MEASUREMENTS, (uint8_t*)data,
sizeof(sps30_data_t), true);
/* The sps30_data_t consists only of floats, so it is safe to treat it as
an array of 32 bit values for swapping to correct endianness */
uint32_t *values = (uint32_t*)data;
/* swap to the endianness of this platform */
for (unsigned i = 0; i < (sizeof(sps30_data_t) / sizeof(uint32_t)); i++) {
values[i] = ntohl(values[i]);
}
return res;
}
int sps30_read_ac_interval(const sps30_t *dev, uint32_t *seconds) {
assert(dev);
int res = _rx_tx_data(dev, SPS30_CMD_RW_AUTOCLEAN, (uint8_t*)seconds,
sizeof(uint32_t), true);
*seconds = ntohl(*seconds);
return res;
}
int sps30_write_ac_interval(const sps30_t *dev, uint32_t seconds)
{
assert(dev);
seconds = htonl(seconds);
int res = _rx_tx_data(dev, SPS30_CMD_RW_AUTOCLEAN, (uint8_t*)&seconds,
sizeof(uint32_t), false);
return res;
}
int sps30_start_fan_clean(const sps30_t *dev)
{
assert(dev);
return _rx_tx_data(dev, SPS30_CMD_START_FAN_CLEAN, NULL, 0, false);
}
int sps30_read_article_code(const sps30_t *dev, char *str, size_t len)
{
assert(dev && str && (len == SPS30_SER_ART_LEN));
return _rx_tx_data(dev, SPS30_CMD_RD_ARTICLE, (uint8_t*)str, len, true);
}
int sps30_read_serial_number(const sps30_t *dev, char *str, size_t len)
{
assert(dev && str && (len == SPS30_SER_ART_LEN));
return _rx_tx_data(dev, SPS30_CMD_RD_SERIAL, (uint8_t*)str, len, true);
}
int sps30_reset(const sps30_t *dev)
{
assert(dev);
return _rx_tx_data(dev, SPS30_CMD_RESET, NULL, 0, false);
}
int sps30_sleep(const sps30_t *dev)
{
assert(dev);
sps30_stop_measurement(dev);
return _rx_tx_data(dev, SPS30_CMD_SLEEP, NULL, 0, false);
}
int sps30_wakeup(const sps30_t *dev)
{
assert(dev);
/* Send I2C start stop sequence to re-enable I2C interface on sensor */
i2c_write_bytes(dev->p.i2c_dev, SPS30_I2C_ADDR, NULL, 0, 0);
return _rx_tx_data(dev, SPS30_CMD_WAKE_UP, NULL, 0, false);
}
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