From mboxrd@z Thu Jan 1 00:00:00 1970 From: Grant Likely Subject: Re: [PATCH] dt: platform: Extract device name from device tree blob Date: Thu, 15 Nov 2012 15:52:46 +0000 Message-ID: <20121115155246.C4EC83E194B@localhost> References: <1352732343-1199-1-git-send-email-per.forlin@stericsson.com> <50A17E30.7030807@stericsson.com> Mime-Version: 1.0 Content-Type: multipart/mixed; boundary="===============6816041666675836764==" Return-path: In-Reply-To: <50A17E30.7030807-0IS4wlFg1OjSUeElwK9/Pw@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" Cc: "devicetree-discuss-uLR06cmDAlY/bJ5BZ2RsiQ@public.gmane.org" , Fredrik SODERSTEDT , "rob.herring-bsGFqQB8/DxBDgjK7y7TUQ@public.gmane.org" , "linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org" , "lee.jones-QSEj5FYQhm4dnm+yROfE0A@public.gmane.org" List-Id: devicetree@vger.kernel.org --===============6816041666675836764== Content-Type: text/plain On Mon, 12 Nov 2012 23:54:40 +0100, Per Förlin wrote: > On 11/12/2012 04:20 PM, Grant Likely wrote: > > On Mon, Nov 12, 2012 at 2:59 PM, Per Forlin wrote: > >> Add support to extract device name from device tree blob. > >> If the property "dev-name" is set in the DTS this name will > >> be used when creating the device. > >> The auxdata_lookup has precedence and will override > >> the "dev-name" property. > > > > Using a 'dev-name' property has the same problem that the 'cell-index' > > properties have in that it is encoding part of the global namespace > > local to the node and it becomes easy to create collisions. Instead of > > this check to see if one of the properties in /aliases points to the > > node and use that for the name. > > > > g. > > > Thanks Grant for your feedback, > > Extract from exynos5250.dtsi: > ----------- > aliases { > spi0 = &spi_0; > spi1 = &spi_1; > spi2 = &spi_2; > }; > > spi_0: spi@12d20000 { > ... > }; > > spi_1: spi@12d30000 { > ... > }; > > spi_2: spi@12d40000 { > ... > }; > --------------- > > Alias refers to the device node. The device node is not aware of the alias. > > How to get a device name from the aliases. > 1. Traverse all aliases for each device node (time consuming if there are many aliases) > 2. Make a new function of_alias_get_name(), today there is only of_alias_get_id() > 3. The functionality of setting device_name based on alias name needs to be optional because one may want to use aliases without changing the name of the device. > All this is feasible but perhaps not optimal. > > I don't really see how come name space is a big issue in this case. The name space of "dev-name" is local to the device node. A child device node can use the same dev-name as the parent (unless I'm mistaken which happens quite often). Introducing yet another property name pollutes the name space of the device node. Still I think the pros are stronger than the cons. > > Do you still prefer to use the name of the Alias? Could you please elaborate a bit more how this can be done in practice? > I would agree with you if there was a reference from the device node to the alias. Oh, I see what you're trying to do. As Lee pointed out you're trying to make the Linux internal way of matching up clocks and regulators happy. That is very much a Linux-kernel internal thing and should be solved in the kernel. Trying to solve it with fixed names in the device tree will cause problems down the road. I though you were wanting to have logical names for the devices that make sense to the user which is how aliases is used now. So, no, don't do this. g. --===============6816041666675836764== Content-Type: text/plain; charset="us-ascii" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Content-Disposition: inline _______________________________________________ devicetree-discuss mailing list devicetree-discuss-uLR06cmDAlY/bJ5BZ2RsiQ@public.gmane.org https://lists.ozlabs.org/listinfo/devicetree-discuss --===============6816041666675836764==--