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

Ajay kumar ajaynumb at gmail.com
Fri Jun 20 08:42:33 CEST 2014


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).

Ajay
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