Hi Sasha, On Tue, Nov 26, 2024 at 09:47:58PM +0100, Sasha Finkelstein via B4 Relay wrote: > Hi. > > This series adds support for Apple touchscreens using the Z2 protocol. > Those are used as the primary touchscreen on mobile Apple devices, and for the > touchbar on laptops using the M-series chips. (T1/T2 laptops have a coprocessor > in charge of speaking Z2 to the touchbar). > > Originally sent as a RFC at https://lore.kernel.org/all/20230223-z2-for-ml-v1-0-028f2b85dc15@xxxxxxxxx/ > The changes since then mostly address the review feedback, but also > add another machine that has this specific controller. > > The extra gpio needed to be toggled turned out to be a quirk of the > j293, normal CS is unusable on it, and a gpio has to be used instead. > (j493 does not have this quirk) I believe this needs to be done at the SPI controller level. See "cs-gpiods" property in Documentation/devicetree/bindings/spi/spi-controller.yaml that, as far as I understand, allows overriding controller's native CS handling with a GPIO when needed. Cc-ing Mark Brown. Thanks. -- Dmitry