update spi clock polarity

- Perform an empty SPI transfer after setting speed and mode
2022-02-22 18:58:20 +01:00
parent 19f8e41c7f
commit d88d7c938f
2 changed files with 9 additions and 0 deletions
--- a/hal/src/fsfw_hal/linux/spi/SpiComIF.cpp
+++ b/hal/src/fsfw_hal/linux/spi/SpiComIF.cpp
@ -401,4 +401,12 @@ void SpiComIF::setSpiSpeedAndMode(int spiFd, spi::SpiModes mode, uint32_t speed)
  if (retval != 0) {
    utility::handleIoctlError("SpiComIF::setSpiSpeedAndMode: Setting SPI speed failed");
  }
+  // This updates the SPI clock default polarity. Only setting the mode does not update
+  // the line state, which can be an issue on mode switches.
+  clockUpdateTransfer.len = 0;
+  retval = ioctl(spiFd, SPI_IOC_MESSAGE(1), &clockUpdateTransfer);
+  if (retval != 0) {
+    utility::handleIoctlError("SpiComIF::setSpiSpeedAndMode: Updating SPI default clock failed");
+  }
+
 }