Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751782AbdFAIrE (ORCPT ); Thu, 1 Jun 2017 04:47:04 -0400 Received: from mail-io0-f180.google.com ([209.85.223.180]:33727 "EHLO mail-io0-f180.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751093AbdFAIrB (ORCPT ); Thu, 1 Jun 2017 04:47:01 -0400 From: Chunyan Zhang To: mturquette@baylibre.com, sboyd@codeaurora.org, robh+dt@kernel.org, mark.rutland@arm.com Cc: linux-clk@vger.kernel.org, linux-kernel@vger.kernel.org, devicetree@vger.kernel.org, zhang.lyra@gmail.com Subject: [PATCH] Documentation: clock: address more for clock-cells property Date: Thu, 1 Jun 2017 16:46:41 +0800 Message-Id: <1496306801-19239-1-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: 1579 Lines: 34 The value of property 'clock-cells' is not determined only by the number of clock outputs in one clock node, it is actually 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, 8 insertions(+), 2 deletions(-) diff --git a/Documentation/devicetree/bindings/clock/clock-bindings.txt b/Documentation/devicetree/bindings/clock/clock-bindings.txt index 2ec489e..cef3db5 100644 --- a/Documentation/devicetree/bindings/clock/clock-bindings.txt +++ b/Documentation/devicetree/bindings/clock/clock-bindings.txt @@ -15,8 +15,14 @@ value of a #clock-cells property in the clock provider node. Required properties: #clock-cells: Number of cells in a clock specifier; Typically 0 for nodes - with a single clock output and 1 for nodes with multiple - clock outputs. + with a single clock output and it must be able to be + referenced without index, and 1 for nodes with single or + multiple clock outputs which have to be referenced by index. + + Please note that if a node with a single clock output + but it has "clock-indices" property (see bellow), it has + to be referenced by index, its "#clock-cells" cannot be + defined 0. Optional properties: clock-output-names: Recommended to be a list of strings of clock output signal -- 2.7.4