From mboxrd@z Thu Jan 1 00:00:00 1970 From: sebastian.hesselbarth@gmail.com (Sebastian Hesselbarth) Date: Tue, 15 Apr 2014 12:26:11 +0200 Subject: [PATCH 2/2] ARM: dts: berlin: add GPIO nodes for the BG2Q In-Reply-To: <20140415180058.2fefca78@xhacker> 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> Message-ID: <534D0943.2050100@gmail.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.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 T?nart 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 T?nart >>> --- >>> 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