Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751937AbdFNKLl (ORCPT ); Wed, 14 Jun 2017 06:11:41 -0400 Received: from mail-vk0-f41.google.com ([209.85.213.41]:33461 "EHLO mail-vk0-f41.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751730AbdFNKLi (ORCPT ); Wed, 14 Jun 2017 06:11:38 -0400 MIME-Version: 1.0 In-Reply-To: References: <1497432104-22609-1-git-send-email-zhang.chunyan@linaro.org> From: Chunyan Zhang Date: Wed, 14 Jun 2017 18:11:37 +0800 Message-ID: Subject: Re: [PATCH v2] Documentation: clock: address more for clock-cells property To: Geert Uytterhoeven Cc: Rob Herring , Michael Turquette , Stephen Boyd , Mark Rutland , linux-clk , "devicetree@vger.kernel.org" , "linux-kernel@vger.kernel.org" , Lyra Zhang Content-Type: text/plain; charset="UTF-8" Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2693 Lines: 69 Hi Geert, On 14 June 2017 at 17:42, Geert Uytterhoeven wrote: > Hi Chunyan, > > On Wed, Jun 14, 2017 at 11:21 AM, Chunyan Zhang > wrote: >> The value of property 'clock-cells' is not determined only by the number >> of clock outputs in one clock node, it is determined by whether the clock >> output in this node can be referenced directly without index. If the >> output clock has to be referenced by a index, the clock-cell of this >> clock node can't be defined 0. >> >> Signed-off-by: Chunyan Zhang >> --- >> Documentation/devicetree/bindings/clock/clock-bindings.txt | 10 ++++++++++ >> 1 file changed, 10 insertions(+) >> >> diff --git a/Documentation/devicetree/bindings/clock/clock-bindings.txt b/Documentation/devicetree/bindings/clock/clock-bindings.txt >> index 2ec489e..e2b76b4 100644 >> --- a/Documentation/devicetree/bindings/clock/clock-bindings.txt >> +++ b/Documentation/devicetree/bindings/clock/clock-bindings.txt >> @@ -18,6 +18,9 @@ Required properties: >> with a single clock output and 1 for nodes with multiple >> clock outputs. >> >> + There's one exception, please see the description for >> + clock-indices below. >> + >> Optional properties: >> clock-output-names: Recommended to be a list of strings of clock output signal >> names indexed by the first cell in the clock specifier. >> @@ -48,6 +51,13 @@ clock-indices: If the identifying number for the clocks in the node >> is not linear from zero, then this allows the mapping of >> identifiers into the clock-output-names array. >> >> + This property not only servers for clocks with multiple > > serves Thanks, I will fix that. > >> + clock outputs, but also for clocks with a single clock >> + output whose identifying number is not zero. > > Why would you want a single clock and a non-zero identifying number? Because of the probably weird hardwire design :) There indeed some clocks like that on the platform I'm working on. > >> + So long as clock-indices is set, clock-cells cannot be >> + set zero. > > Gr{oetje,eeting}s, > > Geert Thanks for your review, Chunyan > > -- > Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org > > In personal conversations with technical people, I call myself a hacker. But > when I'm talking to journalists I just say "programmer" or something like that. > -- Linus Torvalds