eive-obsw/bsp_q7s/spi/Q7sSpiComIF.h
2021-07-15 19:06:57 +02:00

34 lines
1.5 KiB
C++

#ifndef BSP_Q7S_SPI_Q7SSPICOMIF_H_
#define BSP_Q7S_SPI_Q7SSPICOMIF_H_
#include <fsfw/hal/linux/spi/SpiComIF.h>
/**
* @brief This additional communication interface is required because the SPI busses behind the
* devices "/dev/spi2.0" and "dev/spidev3.0" are multiplexed to one SPI interface.
* This was necessary because the processing system spi (/dev/spi2.0) does not support
* frequencies lower than 650 kHz. To reach lower frequencies also the CPU frequency must
* be reduced which leads to other effects compromising kernel drivers.
* The nano avionics reaction wheels require a spi frequency between 150 kHz and 300 kHz
* why an additional AXI SPI core has been implemented in the programmable logic. However,
* the spi frequency of the AXI SPI core is not configurable during runtime. Therefore,
* this communication interface multiplexes either the hard-wired SPI or the AXI SPI to
* the SPI interface. The multiplexing is performed via a GPIO connected to a VHDL
* module responsible for switching between the to SPI peripherals.
*/
class Q7sSpiComIF: public SpiComIF {
public:
/**
* @brief Constructor
*
* @param objectId
* @param gpioComIF
* @param gpioSwitchId The gpio ID of the GPIO connected to the SPI mux module in the PL.
*/
Q7sSpiComIF(object_id_t objectId, GpioIF* gpioComIF, gpioId_t gpioSwitchId);
virtual ~Q7sSpiComIF();
};
#endif /* BSP_Q7S_SPI_Q7SSPICOMIF_H_ */