[RFC 3/6] dt/bindings: Add bindings for Tegra20/30 NOR bus driver
From: Mirza Krak <hidden>
Date: 2016-07-22 19:07:02
Also in:
linux-clk, linux-devicetree, linux-tegra
2016-07-22 11:32 GMT+02:00 Jon Hunter [off-list ref]:
On 21/07/16 21:10, Mirza Krak wrote:quoted
2016-07-21 11:56 GMT+02:00 Jon Hunter [off-list ref]:quoted
I wonder if it is worth mentioning that the chip-select specified in the "nvidia,config" prop should match that in the "ranges" prop unless you have some external decoding logic to provide an external chip-select. Which raises a question, what does the chip-select in the ranges actually represent? I am not sure if there is a common practice here for device tree when boards have external logic to provide additional chip-selects. I am sure this is quite common.I do not understand why CS pin setting in nvidia,config need to match the "ranges" prop? Other then maybe cosmetics.Yes it would be cosmetic. That said, I even wonder if CS needs to be exposed at all given that they all map to the same CPU address space. Couldn't your binding for the CAN devices be as follows? nor at 70009000 { ... can at 48000000 { ... }; can at 48040000 { ... }; };
This has also crossed my mind, maybe just get rid of the "ranges" prop and do like you have above. But then again I do not know what is preferred so I went with "ranges" prop initially.
Problem is if you did have devices on different chip-selects then how would these be handled? They could not point to the same physical address. I am not sure if there is a way to do that in DT?
Having trouble following your though here. We do not have "different" chip-selects? Best Regards Mirza