Hello, On Fri Feb 16, 2024 at 11:33 AM CET, Krzysztof Kozlowski wrote: > On 16/02/2024 11:18, Théo Lebrun wrote: > > > >>> + mobileye,id: > >>> + $ref: /schemas/types.yaml#/definitions/uint32 > >>> + description: Platform-wide controller ID (integer starting from zero). > >> > >> instance indexes are a NAK. You can use i2cN aliases if you must. > >> > >> Why do you need it? To access OLB? If so, add cell args to the OLB > >> phandle instead. > > > > Why we do what we do: I2C controller must write a 2 bit value depending > > on the bus speed. All I2C controllers write into the same register. > > Which register? Your devices do not share IO address space. mobileye,olb is a prop with a phandle to a syscon. That syscon contains the register we are interested in. The Linux code side of things is in the following patch. We use syscon_regmap_lookup_by_phandle(). [PATCH 10/13] i2c: nomadik: support Mobileye EyeQ5 I2C controller https://lore.kernel.org/lkml/20240215-mbly-i2c-v1-10-19a336e91dca@xxxxxxxxxxx/ Thanks, -- Théo Lebrun, Bootlin Embedded Linux and Kernel engineering https://bootlin.com