From mboxrd@z Thu Jan 1 00:00:00 1970 From: Thomas Petazzoni Subject: Re: [PATCH 3.9 1/3] misc: new driver for GPIO-connected 7-segment displays Date: Mon, 7 Jan 2013 20:58:54 +0100 Message-ID: <20130107205854.1f019816@skate> References: <1357576928-29133-1-git-send-email-thomas.petazzoni@free-electrons.com> <1357576928-29133-2-git-send-email-thomas.petazzoni@free-electrons.com> <201301071943.40074.arnd@arndb.de> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <201301071943.40074.arnd-r2nGTMty4D4@public.gmane.org> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: devicetree-discuss-bounces+gldd-devicetree-discuss=m.gmane.org-uLR06cmDAlY/bJ5BZ2RsiQ@public.gmane.org Sender: "devicetree-discuss" To: Arnd Bergmann Cc: Lior Amsalem , Andrew Lunn , Jason Cooper , Greg Kroah-Hartman , devicetree-discuss-uLR06cmDAlY/bJ5BZ2RsiQ@public.gmane.org, linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org List-Id: devicetree@vger.kernel.org Dear Arnd Bergmann, On Mon, 7 Jan 2013 19:43:39 +0000, Arnd Bergmann wrote: > > .../devicetree/bindings/misc/gpio-7seg.txt | 18 +++ > > drivers/misc/Kconfig | 13 ++ > > drivers/misc/Makefile | 1 + > > drivers/misc/gpio-7seg.c | 168 ++++++++++++++++++++ > > I wonder if it would make sense to merge this into the LED subsystem > rather than having it as a standalone driver. Hum, maybe. How do you see it fitting inside the LED subsystem? The purpose of the device is quite different in its userspace to kernel interface, no? > > diff --git a/Documentation/devicetree/bindings/misc/gpio-7seg.txt b/Documentation/devicetree/bindings/misc/gpio-7seg.txt > > new file mode 100644 > > index 0000000..107d178 > > --- /dev/null > > +++ b/Documentation/devicetree/bindings/misc/gpio-7seg.txt > > @@ -0,0 +1,18 @@ > > +* 7-segment driver connected over GPIO through a BCD decoder > > + > > +Required properties: > > +- compatible: "generic,gpio-7seg" > > +- gpios: list of GPIOs to use to control the 7-segment display > > Maybe list the minimum and maximum number of gpio lines here? Indeed. Seems like it should be anywhere between 0 and 32 GPIOs. > > + sdev->dev_attr.attr.name = "value"; > > + sdev->dev_attr.attr.mode = S_IRUGO | S_IWUGO; > > + sdev->dev_attr.show = gpio_7seg_show; > > + sdev->dev_attr.store = gpio_7seg_store; > > Any reason why you are not using the DEVICE_ATTR macro? DEVICE_ATTR declares the structure, and I wanted one per gpio_7seg device, which is dynamically allocated, so I thought that using DEVICE_ATTR was not possible. But now that you point this, I realize that I was stupid. I can perfectly live with one single global 'struct device_attribute' that I register to several devices using device_create_file(), no? That said, is it worth the effort to continue polishing this driver, after seeing the feedback from Greg about it? I don't mind working on it more and fix the problems of course, but if the general answer is that we don't want such a driver in the kernel, then I'd better not spend more time on this. Thanks, Thomas -- Thomas Petazzoni, Free Electrons Kernel, drivers, real-time and embedded Linux development, consulting, training and support. http://free-electrons.com