pebble/src/fw/drivers/i2c.h
2025-01-27 11:38:16 -08:00

97 lines
4.8 KiB
C

/*
* Copyright 2024 Google LLC
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#pragma once
#include "board/board.h"
#include <stdbool.h>
#include <stdint.h>
//! Start using the I2C bus to which \a slave is connected
//! Must be called before any other reads or writes to the slave are performed
//! @param slave I2C slave reference, which will identify the bus to use
void i2c_use(I2CSlavePort *slave);
//! Stop using the I2C bus to which \a slave is connected
//! Call when done communicating with the slave
//! @param slave I2C slave reference, which will identify the bus to release
void i2c_release(I2CSlavePort *slave);
//! Reset the slave
//! Will cycle the power to and re-initialize the bus to which \a slave is connected, if this is
//! supported for the bus.
//! @param slave I2C slave reference, which will identify the bus to be reset
void i2c_reset(I2CSlavePort *slave);
//! Manually bang out the clock on the bus to which \a slave is connected until the data line
//! recovers for a period or we timeout waiting for it to recover
//! Must not be called before \ref i2c_use has been called for the slave
//! @param slave I2C slave reference, which will identify the bus to be recovered
//! @return true if the data line recovered, false otherwise
bool i2c_bitbang_recovery(I2CSlavePort *slave);
//! Read the value of a register
//! Must not be called before \ref i2c_use has been called for the slave
//! @param slave I2C slave to communicate with
//! @param register_address Address of register to read
//! @param result Pointer to destination buffer
//! @return true if transfer succeeded, false if error occurred
bool i2c_read_register(I2CSlavePort *slave, uint8_t register_address, uint8_t *result);
//! Read a sequence of registers starting from \a register_address_start
//! Must not be called before \ref i2c_use has been called for the slave
//! @param slave I2C slave to communicate with
//! @param register_address_start Address of first register to read
//! @param read_size Number of bytes to read
//! @param result_buffer Pointer to destination buffer
//! @return true if transfer succeeded, false if error occurred
bool i2c_read_register_block(I2CSlavePort *slave, uint8_t register_address_start,
uint32_t read_size, uint8_t* result_buffer);
//! Read a block of data without sending a register address before doing so.
//! Must not be called before \ref i2c_use has been called for the slave
//! @param slave I2C slave to communicate with
//! @param read_size Number of bytes to read
//! @param result_buffer Pointer to destination buffer
//! @return true if transfer succeeded, false if error occurred
bool i2c_read_block(I2CSlavePort *slave, uint32_t read_size, uint8_t* result_buffer);
//! Write to a register
//! Must not be called before \ref i2c_use has been called for the slave
//! @param slave I2C slave to communicate with
//! @param register_address Address of register to write to
//! @param value Data value to write
//! @return true if transfer succeeded, false if error occurred
bool i2c_write_register(I2CSlavePort *slave, uint8_t register_address, uint8_t value);
//! Write to a sequence of registers starting from \a register_address_start
//! Must not be called before \ref i2c_use has been called for the slave
//! @param slave I2C slave to communicate with
//! @param register_address_start Address of first register to read
//! @param write_size Number of bytes to write
//! @param buffer Pointer to source buffer
//! @return true if transfer succeeded, false if error occurred
bool i2c_write_register_block(I2CSlavePort *slave, uint8_t register_address_start,
uint32_t write_size, const uint8_t* buffer);
//! Write a block of data without sending a register address before doing so.
//! Must not be called before \ref i2c_use has been called for the slave
//! @param slave I2C slave to communicate with
//! @param write_size Number of bytes to write
//! @param buffer Pointer to source buffer
//! @return true if transfer succeeded, false if error occurred
bool i2c_write_block(I2CSlavePort *slave, uint32_t write_size, const uint8_t* buffer);