I think I don't understand your question. I'm sure that you know that GPIOs 12 to 15 on CM4 will be connected to the same pins on CM5, so the question must be less trivial than that.Are the pins I mapped in the picture the same?
CM5 uses RP1, and although RP1's ALT function pin assignments are based on BCM2711 the ALT function numbers are often different. However, the RP1 pinctrl driver has a built-in mapping from the legacy "brcm,function" numbers to the new scheme, so old-style overlays can often be used on Pi 5 without modification.
Ah - are you referring to the slightly different function names? Some of the RP1 SPI blocks can be run in a mode where they drive 2 or 4 pins at once, making it a dual- or quad-SPI configuration. To accommodate that fact in the function numbering, and neatly sidestepping the problematic "MOSI/MISO" names, SIO0 is always an output, although it can be the LSB of a pair or quartet. SIO1 can either be an input or bit 1 in a pair or quartet. If used, SIO2 and SIO3 are always output bits 2 and 3.
Statistics: Posted by PhilE — Mon Dec 02, 2024 1:17 pm
