From mboxrd@z Thu Jan 1 00:00:00 1970 From: Florian Vaussard Subject: Re: [PATCH 2/5] ARM: dts: OMAP2+: create a DT header for GPIO Date: Wed, 22 May 2013 18:00:32 +0200 Message-ID: <519CEBA0.1080103@epfl.ch> References: <1369232864-14460-1-git-send-email-florian.vaussard@epfl.ch> <1369232864-14460-3-git-send-email-florian.vaussard@epfl.ch> <519CE3BB.3040704@wwwdotorg.org> <20130522153452.GZ10378@atomide.com> Reply-To: florian.vaussard@epfl.ch Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20130522153452.GZ10378@atomide.com> Sender: linux-omap-owner@vger.kernel.org To: Tony Lindgren Cc: Stephen Warren , Benoit Cousson , linux-omap@vger.kernel.org, devicetree-discuss@lists.ozlabs.org, linux-arm-kernel@lists.infradead.org List-Id: devicetree@vger.kernel.org Hello Stephan, Tony, Thank you for your reviews. On 05/22/2013 05:34 PM, Tony Lindgren wrote: > * Stephen Warren [130522 08:32]: >> On 05/22/2013 08:27 AM, Florian Vaussard wrote: >>> Define the OMAP_GPIO macro to conveniently use GPIO inside OMAP DT. >>> For example: >>> >>> gpios = <&gpio6 3 0>; /* GPIO 163 */ >>> >>> can be replaced by >>> >>> gpios = OMAP_GPIO(163, 0); >> >>> diff --git a/include/dt-bindings/gpio/omap-gpio.h b/include/dt-bindings/gpio/omap-gpio.h >> >>> +#define OMAP_GPIO_0_BANK gpio1 >>> +#define OMAP_GPIO_1_BANK gpio1 >>> +#define OMAP_GPIO_2_BANK gpio1 >>> +#define OMAP_GPIO_3_BANK gpio1 >> >> There are a /lot/ of those. Is this really worth it? >> >> If the OMAP GPIO HW is already represented as a bunch of separate DT >> nodes which represent separate GPIO blocks, then I would have thought >> the syntax <&gpioN M 0> more directly represents what would be found in >> the HW manual? If not, surely the DT should have a single node to >> represent a single GPIO controller, which just happens to internally >> support a bunch of register arrays. > > Yes I agree, let's not go back to numbering anything except within the > a single instance. If anything, we can put the gpio number into comments. > From a board point a view, I consider this macro as being easier to use, than having to perform the necessary arithmetic to get the bank + offset for each GPIO when converting existing boards or developing new ones. But I also agree with you, and I was sad not to find a more elegant way. Maybe someone with better preprocessor skills could come up with a better solution? Regards, Florian