raspberrypi
Add support for RP1's SPI target mode
RP1 has two SPI target (slave) interfaces - SPI4 on GPIOs 8-11 and SPI7 with a number of positions from GPIO45 upwards. Until recently, the Linux driver for the Synopsys SPI block did not support target mode, but a patch has just appeared in the next branch that does just that.
This patch set adds the two required patches, rebasing the downstream patches on top of them. Currently there is no spi4-pi5 overlay (the only one we are likely to require), but getting the driver changes in now should shake out any major breakage with the SPI controller instances.
The Forums thread asking about SPI target mode on Pi 5 is here: https://forums.raspberrypi.com/viewtopic.php?t=393684