From: "Mark Brown" <broo...@kernel.org> Sent: Thursday, 16 May, 2024 14:18:00 > On Wed, May 15, 2024 at 03:54:10PM +0200, Elinor Montmasson wrote: >> Add new optional DT property "cpu-system-clock-direction-out" to set >> sysclk direction as "out" for the CPU DAI when using the generic codec. >> It is set for both Tx and Rx. >> If not set, the direction is "in". >> The way the direction value is used is up to the CPU DAI driver >> implementation. > > This feels like we should be using the clock bindings to specify the > clock input of whatever is using the output from the SoC, though that's > a lot more work.
Similarly to patch 7/9, I exposed this parameter because the driver has it, and because there might be CPU DAIs needing this parameter. Otherwise the cpu sysclk direction will always be IN as a default. This parameter could be needed for cases with CPU DAIs, such as an SAI, which can provide or consume Tx/Rx clocks. For these devices I know the sysclk direction should correspond to what was set in the dai format. This new compatible is intended to be used when there is no codec device/driver. There is technically no codec device/driver for which the clock input can be set. Is it a bad idea to allow setting the cpu sysclk direction only ? Should the compatible be limited to use-cases where the cpu sysclk direction cannot be set by the machine driver ? Best regards, Elinor Montmasson
