From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1761437AbdAISGc (ORCPT ); Mon, 9 Jan 2017 13:06:32 -0500 Received: from mail-oi0-f65.google.com ([209.85.218.65]:33899 "EHLO mail-oi0-f65.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S970274AbdAISG3 (ORCPT ); Mon, 9 Jan 2017 13:06:29 -0500 Date: Mon, 9 Jan 2017 12:06:27 -0600 From: Rob Herring To: Shawn Lin Cc: Kishon Vijay Abraham I , devicetree@vger.kernel.org, linux-rockchip@lists.infradead.org, Heiko Stuebner , Douglas Anderson , linux-kernel@vger.kernel.org Subject: Re: [PATCH 1/2] Documentation: phy: introduce new optional property to specify drive impedance Message-ID: <20170109180627.uhkfnyxunksp3s6q@rob-hp-laptop> References: <1483608682-226716-1-git-send-email-shawn.lin@rock-chips.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1483608682-226716-1-git-send-email-shawn.lin@rock-chips.com> User-Agent: Mutt/1.6.2-neo (2016-08-21) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Jan 05, 2017 at 05:31:21PM +0800, Shawn Lin wrote: > We need to modify the drive impedance according to the > different hardware condition. So let's expose this to > the DT. > > Signed-off-by: Shawn Lin > --- > > Documentation/devicetree/bindings/phy/rockchip-emmc-phy.txt | 5 +++++ > 1 file changed, 5 insertions(+) > > diff --git a/Documentation/devicetree/bindings/phy/rockchip-emmc-phy.txt b/Documentation/devicetree/bindings/phy/rockchip-emmc-phy.txt > index e3ea557..731aeb9 100644 > --- a/Documentation/devicetree/bindings/phy/rockchip-emmc-phy.txt > +++ b/Documentation/devicetree/bindings/phy/rockchip-emmc-phy.txt > @@ -14,6 +14,11 @@ specified by name: > access to it), it is strongly suggested. > - clocks: Should have a phandle to the card clock exported by the SDHCI driver. > > +Optional Properties: > +- drive_impedance: Must be one of 33, 40, 50, 66, 100. This property allows > + different boards to specify their own drive impedance depending on the > + hardware condition. Needs a vendor prefix. Don't use '_'. And needs unit suffix (-ohms). > + > Example: > > > -- > 1.9.1 > >