px4-firmware/platforms/common/spi.cpp

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#include <board_config.h>
#ifndef BOARD_DISABLE_I2C_SPI

#include <px4_platform_common/spi.h>

#if BOARD_NUM_SPI_CFG_HW_VERSIONS > 1
void px4_set_spi_buses_from_hw_version()
{
	int hw_version = board_get_hw_version();

	for (int i = 0; i < BOARD_NUM_SPI_CFG_HW_VERSIONS; ++i) {
		if (!px4_spi_buses && px4_spi_buses_all_hw[i].board_hw_version == 0) {
			px4_spi_buses = px4_spi_buses_all_hw[i].buses;
		}

		if (px4_spi_buses_all_hw[i].board_hw_version == hw_version) {
			px4_spi_buses = px4_spi_buses_all_hw[i].buses;
		}
	}

	if (!px4_spi_buses) { // fallback
		px4_spi_buses = px4_spi_buses_all_hw[0].buses;
	}
}

const px4_spi_bus_t *px4_spi_buses{};
#endif

int px4_find_spi_bus(uint32_t devid)
{
	for (int i = 0; i < SPI_BUS_MAX_BUS_ITEMS; ++i) {
		const px4_spi_bus_t &bus_data = px4_spi_buses[i];

		if (bus_data.bus == -1) {
			break;
		}

		if (px4_spi_bus_external(bus_data)) {
			continue;
		}

		for (int j = 0; j < SPI_BUS_MAX_DEVICES; ++j) {
			if (PX4_SPIDEVID_TYPE(devid) == PX4_SPIDEVID_TYPE(bus_data.devices[j].devid) &&
			    PX4_SPI_DEV_ID(devid) == bus_data.devices[j].devtype_driver) {
				return bus_data.bus;
			}
		}
	}

	return -1;
}

bool px4_spi_bus_requires_locking(int bus)
{
	for (int i = 0; i < SPI_BUS_MAX_BUS_ITEMS; ++i) {
		const px4_spi_bus_t &bus_data = px4_spi_buses[i];

		if (bus_data.bus == bus) {
			return bus_data.requires_locking;
		}
	}

	return true;
}


bool px4_spi_bus_external(const px4_spi_bus_t &bus)
{
	return bus.is_external;
}

bool SPIBusIterator::next()
{
	// we have at most 1 match per bus, so we can directly jump to the next bus
	while (++_index < SPI_BUS_MAX_BUS_ITEMS && px4_spi_buses[_index].bus != -1) {
		const px4_spi_bus_t &bus_data = px4_spi_buses[_index];

		if (!board_has_bus(BOARD_SPI_BUS, bus_data.bus)) {
			continue;
		}

		// Note: we use bus_data.is_external here instead of px4_spi_bus_external(),
		// otherwise the chip-select matching does not work if a bus is configured as
		// external/internal, but at runtime the other way around.
		// (On boards where a bus can be internal/external at runtime, it should be
		// configured as external.)
		switch (_filter) {
		case FilterType::InternalBus:
			if (!bus_data.is_external) {
				if (_bus == bus_data.bus || _bus == -1) {
					// find device id
					for (int i = 0; i < SPI_BUS_MAX_DEVICES; ++i) {
						if (PX4_SPI_DEVICE_ID == PX4_SPIDEVID_TYPE(bus_data.devices[i].devid) &&
						    _devid_driver_index == bus_data.devices[i].devtype_driver) {
							_bus_device_index = i;
							return true;
						}
					}
				}
			}

			break;

		case FilterType::ExternalBus:
			if (bus_data.is_external) {
				++_external_bus_counter;
				uint16_t cs_index = _devid_driver_index - 1;

				if (_bus == _external_bus_counter && cs_index < SPI_BUS_MAX_DEVICES &&
				    bus_data.devices[cs_index].cs_gpio != 0) {
					// we know that bus_data.devices[cs_index].devtype_driver == cs_index
					_bus_device_index = cs_index;
					return true;
				}
			}

			break;
		}
	}

	return false;
}

#endif /* BOARD_DISABLE_I2C_SPI */