114 lines
4.1 KiB
C
114 lines
4.1 KiB
C
|
/*
|
||
|
|
* Copyright (c) 2018, Sensirion AG
|
||
|
|
* All rights reserved.
|
||
|
|
*
|
||
|
|
* Redistribution and use in source and binary forms, with or without
|
||
|
|
* modification, are permitted provided that the following conditions are met:
|
||
|
|
*
|
||
|
|
* * Redistributions of source code must retain the above copyright notice, this
|
||
|
|
* list of conditions and the following disclaimer.
|
||
|
|
*
|
||
|
|
* * Redistributions in binary form must reproduce the above copyright notice,
|
||
|
|
* this list of conditions and the following disclaimer in the documentation
|
||
|
|
* and/or other materials provided with the distribution.
|
||
|
|
*
|
||
|
|
* * Neither the name of Sensirion AG nor the names of its
|
||
|
|
* contributors may be used to endorse or promote products derived from
|
||
|
|
* this software without specific prior written permission.
|
||
|
|
*
|
||
|
|
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
|
||
|
|
* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
|
||
|
|
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
|
||
|
|
* ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
|
||
|
|
* LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
|
||
|
|
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
|
||
|
|
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
|
||
|
|
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
|
||
|
|
* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
|
||
|
|
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
|
||
|
|
* POSSIBILITY OF SUCH DAMAGE.
|
||
|
|
*/
|
||
|
|
|
||
|
|
#ifndef SENSIRION_I2C_HAL_H
|
||
|
|
#define SENSIRION_I2C_HAL_H
|
||
|
|
|
||
|
|
#include "sensirion_config.h"
|
||
|
|
#include "common/pimoroni_i2c.hpp"
|
||
|
|
|
||
|
|
#ifdef __cplusplus
|
||
|
|
extern "C" {
|
||
|
|
#endif /* __cplusplus */
|
||
|
|
|
||
|
|
/**
|
||
|
|
* Select the current i2c bus by index.
|
||
|
|
* All following i2c operations will be directed at that bus.
|
||
|
|
*
|
||
|
|
* THE IMPLEMENTATION IS OPTIONAL ON SINGLE-BUS SETUPS (all sensors on the same
|
||
|
|
* bus)
|
||
|
|
*
|
||
|
|
* @param bus_idx Bus index to select
|
||
|
|
* @returns 0 on success, an error code otherwise
|
||
|
|
*/
|
||
|
|
int16_t sensirion_i2c_hal_select_bus(uint8_t bus_idx);
|
||
|
|
|
||
|
|
/**
|
||
|
|
* Initialize all hard- and software components that are needed for the I2C
|
||
|
|
* communication.
|
||
|
|
*/
|
||
|
|
void sensirion_i2c_hal_init(pimoroni::I2C *_i2c);
|
||
|
|
|
||
|
|
/**
|
||
|
|
* Release all resources initialized by sensirion_i2c_hal_init().
|
||
|
|
*/
|
||
|
|
void sensirion_i2c_hal_free(void);
|
||
|
|
|
||
|
|
/**
|
||
|
|
* Execute one read transaction on the I2C bus, reading a given number of bytes.
|
||
|
|
* If the device does not acknowledge the read command, an error shall be
|
||
|
|
* returned.
|
||
|
|
*
|
||
|
|
* @param address 7-bit I2C address to read from
|
||
|
|
* @param data pointer to the buffer where the data is to be stored
|
||
|
|
* @param count number of bytes to read from I2C and store in the buffer
|
||
|
|
* @returns 0 on success, error code otherwise
|
||
|
|
*/
|
||
|
|
int8_t sensirion_i2c_hal_read(uint8_t address, uint8_t* data, uint16_t count);
|
||
|
|
|
||
|
|
/**
|
||
|
|
* Execute one write transaction on the I2C bus, sending a given number of
|
||
|
|
* bytes. The bytes in the supplied buffer must be sent to the given address. If
|
||
|
|
* the slave device does not acknowledge any of the bytes, an error shall be
|
||
|
|
* returned.
|
||
|
|
*
|
||
|
|
* @param address 7-bit I2C address to write to
|
||
|
|
* @param data pointer to the buffer containing the data to write
|
||
|
|
* @param count number of bytes to read from the buffer and send over I2C
|
||
|
|
* @returns 0 on success, error code otherwise
|
||
|
|
*/
|
||
|
|
int8_t sensirion_i2c_hal_write(uint8_t address, const uint8_t* data,
|
||
|
|
uint16_t count);
|
||
|
|
|
||
|
|
/**
|
||
|
|
* Sleep for a given number of microseconds. The function should delay the
|
||
|
|
* execution approximately, but no less than, the given time.
|
||
|
|
*
|
||
|
|
* When using hardware i2c:
|
||
|
|
* Despite the unit, a <10 millisecond precision is sufficient.
|
||
|
|
*
|
||
|
|
* When using software i2c:
|
||
|
|
* The precision needed depends on the desired i2c frequency, i.e. should be
|
||
|
|
* exact to about half a clock cycle (defined in
|
||
|
|
* `SENSIRION_I2C_CLOCK_PERIOD_USEC` in `sensirion_sw_i2c_gpio.h`).
|
||
|
|
*
|
||
|
|
* Example with 400kHz requires a precision of 1 / (2 * 400kHz) == 1.25usec.
|
||
|
|
*
|
||
|
|
* @param useconds the sleep time in microseconds
|
||
|
|
*/
|
||
|
|
void sensirion_i2c_hal_sleep_usec(uint32_t useconds);
|
||
|
|
|
||
|
|
#ifdef __cplusplus
|
||
|
|
}
|
||
|
|
#endif /* __cplusplus */
|
||
|
|
|
||
|
|
#endif /* SENSIRION_I2C_HAL_H */
|