Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752183AbdFNJWN (ORCPT ); Wed, 14 Jun 2017 05:22:13 -0400 Received: from mail-pf0-f175.google.com ([209.85.192.175]:33993 "EHLO mail-pf0-f175.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751919AbdFNJWJ (ORCPT ); Wed, 14 Jun 2017 05:22:09 -0400 From: Chunyan Zhang To: robh+dt@kernel.org, mturquette@baylibre.com, sboyd@codeaurora.org Cc: mark.rutland@arm.com, linux-clk@vger.kernel.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, zhang.lyra@gmail.com Subject: [PATCH v2] Documentation: clock: address more for clock-cells property Date: Wed, 14 Jun 2017 17:21:44 +0800 Message-Id: <1497432104-22609-1-git-send-email-zhang.chunyan@linaro.org> X-Mailer: git-send-email 2.7.4 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1723 Lines: 41 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 + clock outputs, but also for clocks with a single clock + output whose identifying number is not zero. + + So long as clock-indices is set, clock-cells cannot be + set zero. + For example, if we have two clocks <&oscillator 1> and <&oscillator 3>: oscillator { -- 2.7.4