Re: [PATCH] fbdev: simplefb: add support for 'memory-region' property on DT node

From: Andy Shevchenko
Date: Thu Feb 01 2018 - 14:03:37 EST


On Thu, Feb 1, 2018 at 5:56 PM, Bartlomiej Zolnierkiewicz
<b.zolnierkie@xxxxxxxxxxx> wrote:
> On Tuesday, January 23, 2018 08:34:56 PM Kunihiko Hayashi wrote:
>> Enables 'memory-region' property referring to the memory description on
>> the reserved-memory node in case of devicetree use.
>> If there is no 'reg' property that specifies the address and size of
>> the framebuffer, the address and size written in the memory description
>> on the reserved-memory node can be used for the framebuffer.
>>
>> Furthermore, the reserved-memory node needs to have "no-map" attributes
>> because simplefb driver maps the region by ioremap_wc().
>>
>> Signed-off-by: Kunihiko Hayashi <hayashi.kunihiko@xxxxxxxxxxxxx>

>> +- memory-region: phandle to a node describing memory region as framebuffer
>> + memory instead of reg property. The node should include
>> + 'no-map'.

>> mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
>> + if (!mem)
>> + mem = simplefb_parse_dt_reserved_mem(&pdev->dev);

I'm not sure I understood why you need this entire function?

Put your memory resource ('reg' property) as part of reserved memory
with necessary flags.

--
With Best Regards,
Andy Shevchenko