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/*
* Copyright 2020 Google LLC
*
* SPDX-License-Identifier: Apache-2.0
*/
#ifndef ZEPHYR_INCLUDE_DRIVERS_SPI_SPI_EMUL_H_
#define ZEPHYR_INCLUDE_DRIVERS_SPI_SPI_EMUL_H_
/**
* @file
*
* @brief Public APIs for the SPI emulation drivers.
*/
#include <zephyr/types.h>
#include <device.h>
/**
* @brief SPI Emulation Interface
* @defgroup spi_emul_interface SPI Emulation Interface
* @ingroup io_emulators
* @{
*/
#ifdef __cplusplus
extern "C" {
#endif
struct spi_msg;
struct spi_emul_api;
/** Node in a linked list of emulators for SPI devices */
struct spi_emul {
sys_snode_t node;
/* API provided for this device */
const struct spi_emul_api *api;
/* SPI chip-slect of the emulated device */
uint16_t chipsel;
};
/**
* Passes SPI messages to the emulator. The emulator updates the data with what
* was read back.
*
* @param emul Emulator instance
* @param config Pointer to a valid spi_config structure instance.
* Pointer-comparison may be used to detect changes from
* previous operations.
* @param tx_bufs Buffer array where data to be sent originates from,
* or NULL if none.
* @param rx_bufs Buffer array where data to be read will be written to,
* or NULL if none.
*
* @retval 0 If successful.
* @retval -EIO General input / output error.
*/
typedef int (*spi_emul_io_t)(struct spi_emul *emul,
const struct spi_config *config,
const struct spi_buf_set *tx_bufs,
const struct spi_buf_set *rx_bufs);
/**
* Register an emulated device on the controller
*
* @param dev Device that will use the emulator
* @param name User-friendly name for this emulator
* @param emul SPI emulator to use
* @return 0 indicating success (always)
*/
int spi_emul_register(const struct device *dev, const char *name,
struct spi_emul *emul);
/** Definition of the emulator API */
struct spi_emul_api {
spi_emul_io_t io;
};
/**
* Back door to allow an emulator to retrieve the host configuration.
*
* @param dev SPI device associated with the emulator
* @return Bit-packed 32-bit value containing the device's runtime configuration
*/
uint32_t spi_emul_get_config(const struct device *dev);
#ifdef __cplusplus
}
#endif
/**
* @}
*/
#endif /* ZEPHYR_INCLUDE_DRIVERS_SPI_SPI_EMUL_H_ */