eive-obsw/bsp_q7s/callbacks/rwSpiCallback.h

#ifndef BSP_Q7S_RW_SPI_CALLBACK_H_
#define BSP_Q7S_RW_SPI_CALLBACK_H_

#include "fsfw/returnvalues/returnvalue.h"
#include "fsfw_hal/common/gpio/GpioCookie.h"
#include "fsfw_hal/linux/spi/SpiComIF.h"

namespace rwSpiCallback {

//! This is the end and start marker of the frame datalinklayer
static constexpr uint8_t FLAG_BYTE = 0x7E;

/**
 * @brief   This is the callback function to send commands to the nano avionics reaction wheels and
 *          receive the replies.
 *
 * @details The data to sent are additionally encoded according to the HDLC framing defined in the
 *          datasheet of the reaction wheels:
 *          https://eive-cloud.irs.uni-stuttgart.de/index.php/apps/files/?dir=/EIVE_IRS/
 *          Arbeitsdaten/08_Used%20Components/Nanoavionics_Reactionwheels&fileid=181622
 *          Each command entails exactly one reply which will also be read in and decoded by this
 *          function.
 *          Because the reaction wheels require a spi clock frequency of maximum 300 kHZ and minimum
 *          150 kHz which is not supported by the processing system SPI peripheral an AXI SPI core
 *          has been implemented in the programmable logic. This AXI SPI core works with a fixed
 *          frequency of 250 kHz.
 *          To allow the parallel usage of the same physical SPI bus, a VHDL module has been
 *          implemented which is able to disconnect the hard-wired SPI peripheral of the PS and
 *          route the AXI SPI to the SPI lines.
 *          To switch between the to SPI peripherals, an EMIO is used which will also be controlled
 *          by this function.
 */
ReturnValue_t spiCallback(SpiComIF* comIf, SpiCookie* cookie, const uint8_t* sendData,
                          size_t sendLen, void* args);

}  // namespace rwSpiCallback
#endif /* BSP_Q7S_RW_SPI_CALLBACK_H_ */