Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756861AbaF3SeY (ORCPT ); Mon, 30 Jun 2014 14:34:24 -0400 Received: from mail-lb0-f178.google.com ([209.85.217.178]:42498 "EHLO mail-lb0-f178.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756819AbaF3SeV (ORCPT ); Mon, 30 Jun 2014 14:34:21 -0400 MIME-Version: 1.0 In-Reply-To: References: <53AB1CC1.4010907@codeaurora.org> <53ACB568.4000903@codeaurora.org> <20140627015354.32686.83046@quantum> From: Rob Herring Date: Mon, 30 Jun 2014 13:33:59 -0500 Message-ID: Subject: Re: [PATCH 2/2] cpufreq: cpu0: Extend support beyond CPU0 To: Viresh Kumar Cc: Mike Turquette , Grant Likely , Stephen Boyd , "Rafael J. Wysocki" , Shawn Guo , Lists linaro-kernel , "linux-pm@vger.kernel.org" , Linux Kernel Mailing List , Arvind Chauhan , "linux-arm-kernel@lists.infradead.org" , linux-arm-msm@vger.kernel.org, Sachin Kamat , Thomas P Abraham , Nishanth Menon , Tomasz Figa , Mark Brown , Mark Rutland Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Jun 30, 2014 at 2:57 AM, Viresh Kumar wrote: > On 27 June 2014 07:45, Viresh Kumar wrote: >> On 27 June 2014 07:23, Mike Turquette wrote: >>>> but it isn't future-proof if/when the clock framework starts returning >>>> dynamically allocated clock pointers for each clk_get() invocation. >>>> Maybe we need a function in the common clock framework that tells us if >>>> the clocks are the same either via DT or by taking two clock pointers? >>> >>> I looked through the patch briefly and did not see why we would need to >>> do this. Any hint? >> >> We want to know which CPUs are sharing clock line, so that we can >> fill affected-cpus field of cpufreq core. > > What about comparing "clocks" property in cpu DT nodes? What if a different clock is selected for some reason. I think a clock api function would be better. That being said, I don't really have any issue with such a function. Some comments on the implementation. > > @Rob/Grant: I tried looking for an existing routine to do that, but couldn't > find it. And so wrote one. > > I am not good at DT stuff and so I do hope there would be few correction > required here. Let me know if this can be added to drivers/of/base.c : > > +/** > + * of_property_match - Match property in two nodes > + * @np1, np2: Nodes to match > + * @list_name: property to match > + * > + * Returns 1 on match, 0 on no match, and error for missing property. > + */ > +static int of_property_match(const struct device_node *np1, > + const struct device_node *np2, > + const char *list_name) > +{ > + const __be32 *list1, *list2, *list1_end; s/list/prop/ Everywhere. > + int size1, size2; > + phandle phandle1, phandle2; > + > + /* Retrieve the list property */ > + list1 = of_get_property(np1, list_name, &size1); > + if (!list1) > + return -ENOENT; > + > + list2 = of_get_property(np2, list_name, &size2); > + if (!list2) > + return -ENOENT; > + > + if (size1 != size2) > + return 0; > + > + list1_end = list1 + size1 / sizeof(*list1); > + > + /* Loop over the phandles */ > + while (list1 < list1_end) { > + phandle1 = be32_to_cpup(list1++); > + phandle2 = be32_to_cpup(list2++); > + > + if (phandle1 != phandle2) > + return 0; > + } You can just do a memcmp here. This is wrong anyway because you don't know #clock-cells size. Rob -- 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/