On Thu, 20 Feb 2025 19:26:41 +0100 Théo Lebrun theo.lebrun@bootlin.com wrote:
That used to exist! I cannot see how it could be a good idea to reintroduce the distinction though.
commit eca3930163ba8884060ce9d9ff5ef0d9b7c7b00f Author: Grant Likely grant.likely@secretlab.ca Date: Tue Jun 8 07:48:21 2010 -0600
of: Merge of_platform_bus_type with platform_bus_type
I don't really see how an of_platform bus would make sense. OF is not a bus at all, it's a way of providing HW description to an operating system.
What would IMO make a lot more sense is mmio_bus, for Memory-Mapped I/O peripherals. mmio_device can be described through OF, through old-style board.c, possibly through ACPI, or other means.
But in my eyes, the current platform bus is exactly this: the bus for MMIO devices. It would have be clearer to name it mmio_bus, and that would have probably prevented abuses of the platform bus for things that aren't memory-mapped peripherals.
But clearly any bus that has "OF" in its name is wrong, as OF cannot be a bus. Keep in mind that OF allows to describe not only MMIO devices, but also I2C devices, SPI devices, MMC/SDIO devices, PCI devices, USB devices, etc. OF is a description of the HW, not a bus.
Best regards,
Thomas