Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754268AbaDOK0T (ORCPT ); Tue, 15 Apr 2014 06:26:19 -0400 Received: from mail-ee0-f44.google.com ([74.125.83.44]:58271 "EHLO mail-ee0-f44.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750899AbaDOK0R (ORCPT ); Tue, 15 Apr 2014 06:26:17 -0400 Message-ID: <534D0943.2050100@gmail.com> Date: Tue, 15 Apr 2014 12:26:11 +0200 From: Sebastian Hesselbarth User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:24.0) Gecko/20100101 Thunderbird/24.4.0 To: Jisheng Zhang CC: =?UTF-8?B?QW50b2luZSBUw6luYXJ0?= , "alexandre.belloni@free-electrons.com" , Jimmy Xu , "linux-arm-kernel@lists.infradead.org" , "devicetree@vger.kernel.org" , "linux-kernel@vger.kernel.org" Subject: Re: [PATCH 2/2] ARM: dts: berlin: add GPIO nodes for the BG2Q References: <1397549245-3338-1-git-send-email-antoine.tenart@free-electrons.com> <1397549245-3338-3-git-send-email-antoine.tenart@free-electrons.com> <534CFA77.9030108@gmail.com> <20140415180058.2fefca78@xhacker> In-Reply-To: <20140415180058.2fefca78@xhacker> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 04/15/2014 12:00 PM, Jisheng Zhang wrote: > On Tue, 15 Apr 2014 02:23:03 -0700 > Sebastian Hesselbarth 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 >>> --- >>> 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/