e7dd7abc0e
Some I2C peripherals like TI charger or gauge chips need support for I2C clock stretching. This patch includes that and makes these modules usable with I2C emulation over GPIO. Signed-off-by: Bas van Loon <bas@arch-embedded.com>
75 lines
2.2 KiB
C
75 lines
2.2 KiB
C
/*
|
|
* Copyright (c) 2017 Linaro Ltd.
|
|
*
|
|
* SPDX-License-Identifier: Apache-2.0
|
|
*/
|
|
|
|
/**
|
|
* @brief Functions for setting and getting the state of the I2C lines.
|
|
*
|
|
* These need to be implemented by the user of this library.
|
|
*/
|
|
struct i2c_bitbang_io {
|
|
/* Set the state of the SCL line (zero/non-zero value) */
|
|
void (*set_scl)(void *io_context, int state);
|
|
#ifdef CONFIG_I2C_GPIO_CLOCK_STRETCHING
|
|
/* Return the state of the SCL line (zero/non-zero value) */
|
|
int (*get_scl)(void *io_context);
|
|
#endif
|
|
/* Set the state of the SDA line (zero/non-zero value) */
|
|
void (*set_sda)(void *io_context, int state);
|
|
/* Return the state of the SDA line (zero/non-zero value) */
|
|
int (*get_sda)(void *io_context);
|
|
};
|
|
|
|
/**
|
|
* @brief Instance data for i2c_bitbang
|
|
*
|
|
* A driver or other code wishing to use the i2c_bitbang library should
|
|
* create one of these structures then use it via the library APIs.
|
|
* Structure members are private, and shouldn't be accessed directly.
|
|
*/
|
|
struct i2c_bitbang {
|
|
const struct i2c_bitbang_io *io;
|
|
void *io_context;
|
|
uint32_t delays[2];
|
|
uint32_t dev_config;
|
|
};
|
|
|
|
/**
|
|
* @brief Initialize an i2c_bitbang instance
|
|
*
|
|
* @param bitbang The instance to initialize
|
|
* @param io Functions to use for controlling I2C bus lines
|
|
* @param io_context Context pointer to pass to i/o functions when then are
|
|
* called.
|
|
*/
|
|
void i2c_bitbang_init(struct i2c_bitbang *bitbang,
|
|
const struct i2c_bitbang_io *io, void *io_context);
|
|
|
|
/**
|
|
* Implementation of the functionality required by the 'configure' function
|
|
* in struct i2c_driver_api.
|
|
*/
|
|
int i2c_bitbang_configure(struct i2c_bitbang *bitbang, uint32_t dev_config);
|
|
|
|
/**
|
|
* Implementation of the functionality required by the 'get_config' function
|
|
* in struct i2c_driver_api.
|
|
*/
|
|
int i2c_bitbang_get_config(struct i2c_bitbang *context, uint32_t *config);
|
|
|
|
/**
|
|
* Implementation of the functionality required by the 'recover_bus'
|
|
* function in struct i2c_driver_api.
|
|
*/
|
|
int i2c_bitbang_recover_bus(struct i2c_bitbang *bitbang);
|
|
|
|
/**
|
|
* Implementation of the functionality required by the 'transfer' function
|
|
* in struct i2c_driver_api.
|
|
*/
|
|
int i2c_bitbang_transfer(struct i2c_bitbang *bitbang,
|
|
struct i2c_msg *msgs, uint8_t num_msgs,
|
|
uint16_t slave_address);
|