lkml.org 
[lkml]   [2014]   [Apr]   [15]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [PATCH 2/2] ARM: dts: berlin: add GPIO nodes for the BG2Q
On 04/15/2014 12:00 PM, Jisheng Zhang wrote:
> On Tue, 15 Apr 2014 02:23:03 -0700
> Sebastian Hesselbarth <sebastian.hesselbarth@gmail.com> wrote:
>> On 04/15/2014 10:07 AM, Antoine Ténart wrote:
>>> The Marvell Berlin BG2Q has 6 GPIO ports compatible with the
>>> snps,dw-apb-gpio driver. This patch add the corresponding device tree
>>> nodes.
>>>
>>> Signed-off-by: Antoine Ténart <antoine.tenart@free-electrons.com>
>>> ---
>>> arch/arm/boot/dts/berlin2q.dtsi | 102
>>> ++++++++++++++++++++++++++++++++++++++++ 1 file changed, 102 insertions(+)
>>>
>>> diff --git a/arch/arm/boot/dts/berlin2q.dtsi
>>> b/arch/arm/boot/dts/berlin2q.dtsi index e6e556055dfc..b2625f896bc5 100644
>>> --- a/arch/arm/boot/dts/berlin2q.dtsi
>>> +++ b/arch/arm/boot/dts/berlin2q.dtsi
[...]
>>> + compatible =
>>> "snps,dw-apb-gpio-port";
>>> + gpio-controller;
>>> + #gpio-cells = <2>;
>>> + snps,nr-gpios = <32>;
>>
>> 32 gpio pins for each of the 6 GPIO controllers? Either BG2Q is a GPIO
>
> Yes, BG2Q support 32 pins every port

Wow. Thanks for confirming this!

>> I am fine with using nr-gpios property now, but I guess BG2Q also
>> has that CONFIG[1,2] registers to actually read out the features
>> synthesized in? If I find some time, I'll prepare a patch for
>> dw-apb-gpio to exploit that (optional) information instead of
>> using nr-gpios.
>
> The problem is CONFIG1/2 registers don't exist on some versions.
> For example, the version used in BG2/BG2CD. So nr-gpio is necessary
> if we want to support these versions.

Hmm, are you sure about BG2? I remember reading it and it contains
sane values. Anyway, a proper patch for dw-apb-gpio would include
checking for sane (e.g. non-zero) values. And nr-gpios will always
stay as fall-back just because e.g. sunxi does not have the CONFIG
registers.

Sebastian

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/

\
 
 \ /
  Last update: 2014-04-15 12:41    [W:0.071 / U:0.364 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site