[PATCH 0/2] usb: exynos: Fix compatible strings used for device

[Vivek Gautam]

Hi Kukjin,


On Tue, Jan 22, 2013 at 11:05 AM, Kukjin Kim <kgene.kim at samsung.com> wrote:
> Sylwester Nawrocki wrote:
>>
>> On 12/24/2012 09:13 AM, Vivek Gautam wrote:
>> >>>> These two changes look good to me.  For both of them:
>> >>>>
>> >>>> Reviewed-by: Doug Anderson<dianders at chromium.org>
>> >>>
>> >>> Well, I have another idea. Yes, I know, specific chip name should be
> used.
>> >> But
>> >>> you know the specific chip name in compatible can cause another
>> confusion
>> >>> on other SoC which has same IP. So I think, we need to consider to use
>> >>> common name or any specific name not chip in compatible for IP/driver
>> like
>> >>> following?
>> >>>
>> >>> -     { .compatible = "samsung,exynos-dwc3" },
>> >>> +     { .compatible = "samsung,synopsis-dwc3" },
>> >>>
>> >>> Or if any version or something, how about following?
>> >>>
>> >>> +     { .compatible = "samsung,dwc-v3" },
>> >>>
>> > Well, yes the newer SoCs with same IP using the chip name can cause some
>> > confusion, but won't it be fine that -
>> > "Newer parts using the same core can claim compatibility by
>> > including the older string in the compatible list" - as quoted by Grant
> Likely
>> >
>> > Or, can we try another option, using multiple compatible strings for
>> > SoC specific
>> > in of_match_table, so that we don't create any confusion by using same
>> > compatible for newer SoCs also. Like,
>> >
>> > -     { .compatible = "samsung,exynos-dwc3" },
>> > +     { .compatible = "samsung,exynos5250-dwc3" },
>> > +     { .compatible =<new SoC using same IP>  },
>>
>> Yes, why not just use an SoC name where given IP first appeared ? I
> believe
>> IP revision numbers are not always well documented. Also when an IP is
>> instantiated multiple times in specific SoC, its revision number might not
>> be sufficient to determine the system integration details for each
> instance.
>> I think having version for some devices and SoC name for others just adds
>> to the confusion. Thus using specific chip name in the compatible property
>> seems more clear to me.
>>
> Well, I don't think so. Let's see the DMAC PL330. Its compatible is
> "arm,pl330" and "arm,primecell" not SoC/Chip name. I think DWC is a same
> case or at least similar.
>
> You know, the DWC is a IP from Synopsis and I _Believe_ it has a kind of
> version and it can be used for identify.
>

Right, DWC has version number, but that being the kind of USB controller
(USB 2.0 and USB 3.0)

DWC2: USB High Speed controller (as also indicated in the patch from
Paul: [RFC PATCH 0/6] DWC2 DesignWare HS OTG driver)
DWC3: USB Super Speed controller

Is it fine if we use something like shown below, as suggested by you earlier ?

-     { .compatible = "samsung,exynos-dwc3" },
+     { .compatible = "samsung,synopsis-dwc3" }




-- 
Thanks & Regards
Vivek