Question regarding clocks in the DW-HDMI DT bindings

[Vladimir Zapolskiy]

On 11/25/2016 03:06 PM, Fabio Estevam wrote:
> Hi Vladimir,
>
> On Fri, Nov 25, 2016 at 11:00 AM, Vladimir Zapolskiy
> <vladimir_zapolskiy at mentor.com> wrote:
>
>> according to the DTSI files in the vanilla kernel DW HDMI IP is found
>> only on iMX6Q/D and iMX6DL/iMX6S SoCs (but please double check it),
>> so this approach should work ideally.
>
> After thinking more about this I think we can not get rid of "gpr". If
> we have a new i.MX SoC that is not compatible with
> "fsl,imx6q-iomuxc-gpr" then the lookup will fail.
>

Practically and when it becomes needed it should be possible to add SoC
specific hooks related to IOMUX_GPRx controls on basis of device
compatibles bound to the SoC variant.

Hypothetically if in future there is one more iMX SoC with a similar PCIe
or SATA controller but different GPR controls, to preserve backward
compatibility with old iMX6* DTB firmware the same handling of device
compatibles must be done in the drivers.

>> I see that the same has already been done in PCIe and SATA drivers,
>> but please consider to send a similar change against iMX LDB driver
>
> The i.MX LDB driver is also used on imx53, so we cannot search for
> "fsl,imx6q-iomuxc-gpr" compatible, as it will fail on imx53.
>
> So it seems we need to keep the "gpr" property in this case.
>

Right, I missed it. By chance GPR controls of LDB/LVDS are the same
on iMX53 and iMX6*, otherwise the driver shall care about GPR controls
differently, for example get a SoC specific GPR device compatible.

Nevertheless it is just a suggestion and it may remain just a mental
exercise of how to beautify/standardize iMX device binding descriptions.

--
With best wishes,
Vladimir