OpenRTX/platform/drivers/SPI/spi_custom.h

90 wiersze
3.5 KiB
C

/***************************************************************************
* Copyright (C) 2024 - 2025 by Federico Amedeo Izzo IU2NUO, *
* Niccolò Izzo IU2KIN *
* Frederik Saraci IU2NRO *
* Silvano Seva IU2KWO *
* *
* This program is free software; you can redistribute it and/or modify *
* it under the terms of the GNU General Public License as published by *
* the Free Software Foundation; either version 3 of the License, or *
* (at your option) any later version. *
* *
* This program is distributed in the hope that it will be useful, *
* but WITHOUT ANY WARRANTY; without even the implied warranty of *
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the *
* GNU General Public License for more details. *
* *
* You should have received a copy of the GNU General Public License *
* along with this program; if not, see <http://www.gnu.org/licenses/> *
***************************************************************************/
#ifndef SPI_CUSTOM_H
#define SPI_CUSTOM_H
#include <peripherals/spi.h>
#ifdef __cplusplus
extern "C" {
#endif
/**
* This module allows to create an SPI device with a custom implementation of
* the bus transfer function. An example usage is to create an SPI device using
* an high-performance bitbanging routine.
*/
/**
* Transfer single byte on the SPI bus.
*
* @param dev: SPI device handle.
* @param tx: byte to be sent.
* @return byte received from remote device.
*/
typedef uint8_t (*spi_func)(const void *priv, uint8_t tx);
/**
* Implementation of the SPI transfer function.
*
* @param dev: SPI device handle.
* @param txBuf: pointer to TX buffer, can be NULL.
* @param rxBuf: pointer to RX buffer, can be NULL.
* @param size: number of bytes to transfer.
* @return zero on success, a negative error code otherwise.
*/
int spiCustom_transfer(const struct spiDevice *dev, const void *txBuf,
void *rxBuf, const size_t size);
/**
* Custom SPI device descriptor.
*/
struct spiCustomDevice
{
spi_transfer_impl transfer; ///< Device-specific implementation of the SPI transfer function
const void *priv; ///< Pointer to device driver private data
pthread_mutex_t *mutex; ///< Pointer to mutex for exclusive access
spi_func spiFunc; ///< Pointer to driver configuration data.
};
/**
* Instantiate a custom SPI device.
*
* @param name: device name.
* @param impl: user-provided implementation of the single byte transfer function.
* @param args: pointer to user-defined arguments.
* @param mutx: pointer to mutex, or NULL.
*/
#define SPI_CUSTOM_DEVICE_DEFINE(name, impl, args, mutx) \
const struct spiCustomDevice name = \
{ \
.transfer = spiCustom_transfer, \
.priv = args, \
.mutex = mutx, \
.spiFunc = impl \
};
#ifdef __cplusplus
}
#endif
#endif /* SPI_CUSTOM_H */