[U-Boot] [PATCH 04/10] video: exynos_fimd: Add framework to disable FIMD sysmmu

[Simon Glass]

Hi Ajay,

On 20 June 2014 00:42, Ajay kumar <ajaynumb at gmail.com> wrote:
> Hi Simon,
>
>
> On Fri, Jun 20, 2014 at 8:59 AM, Simon Glass <sjg at google.com> wrote:
>> On 17 June 2014 03:06, Ajay Kumar <ajaykumar.rs at samsung.com> wrote:
>>> On Exynos5420 and newer versions, the FIMD sysmmus are in
>>> "on state" by default.
>>> We have to disable them in order to make FIMD DMA work.
>>> This patch adds the required framework to exynos_fimd driver,
>>> and disables FIMD sysmmu on Exynos5420.
>>>
>>> Signed-off-by: Ajay Kumar <ajaykumar.rs at samsung.com>
>>
>> Acked-by: Simon Glass <sjg at chromium.org>
>> Tested-by: Simon Glass <sjg at chromium.org>
>>
>> (I assume this is the same device tree binding as Linux?)
> Actually, No!
> Kernel has a generic binding named "samsung,sysmmu-v3.3", and it is common
> for all sysmmu nodes. There is a seperate IOMMU driver to handle the same.
> We can port the device probing part from kernel to u-boot, but we would need
> to add seperate driver(since the name is generic) to handle the same.
> That driver, even though being generic, will be used only by FIMD
> sysmmus(that too, just to turn them off).

OK. I suppose you could add a very short new C file with a function
which finds the device tree node by its compatible string or whatever,
and then updates the hardware.

Regards,
Simon