RE: [PATCH v3 2/2] ARM: EXYNOS: Add Gscaler device from DT

[Kukjin Kim <kgene.kim@samsung.com>]

Thomas Abraham wrote:
> 
> On 1 August 2012 12:10, Kukjin Kim <kgene.kim@samsung.com> wrote:
> > Shaik Ameer Basha wrote:
> 
> [...]
> 
> >> +* Samsung Exynos5 Gscaler device
> >> +
> >> +Gscaler is used for scaling and color space conversion on EXYNOS5
SoCs.
> >> +
> >> +Required properties:
> >> +- compatible: should be "samsung,exynos5250-gsc"
> >
> > IMO, should be "samsung,exynos5-gsc" because upcoming EXYNOS5 SoCs can
> use
> > same gscaler driver.
> 
> The compatible string should always be specific and it should clearly
> identify the type of the controller. If there are other variants of
> the GSC controller in previous of upcoming SoC's, then those
> controllers will have a different compatible value.
> 
As I commented, there will be no differences for gscaler between EXYNOS5
SoCs. So IMO, the 'exynos5-gsc' is clear enough for compatible string of
EXYNOS5 Gscaler.

> This allows device drivers to know the type of the controller and
> handle the differences among them. And, the node in the dts/dtsi file
> should always claim compatibility to the base version of the
> controller that the platform supports.
> 
> So the compatible value "samsung,exynos5250-gsc" is right one. If a
> new SoC in the Exynos5 family has the same GSC controller as that in
> Exynos5250 (no difference at all), then GSC device node in its dts
> file can continue to claim compatibility to Exynos5250 type. The

I don't think so...

> "samsung,s3c2410-wdt is an example of this case which has been used on
> all Samsung SoC's .
> 
I think, the case of 's3c2410-wdt' is different because you know, the name
has been used for a long time in addition, the name of driver is
s3c2410_wdt.c. But in this case, gscaler should be same on EXYNOS5 SoCs
which is including upcoming, so I don't see why we should use
'exynos5250-gsc' for all of EXYNOS5 series.

Thanks.

Best regards,
Kgene.
--
Kukjin Kim <kgene.kim@samsung.com>, Senior Engineer,
SW Solution Development Team, Samsung Electronics Co., Ltd.