From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1162271AbdAFApt (ORCPT ); Thu, 5 Jan 2017 19:45:49 -0500 Received: from lucky1.263xmail.com ([211.157.147.134]:57252 "EHLO lucky1.263xmail.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752303AbdAFApN (ORCPT ); Thu, 5 Jan 2017 19:45:13 -0500 X-263anti-spam: KSV:0; X-MAIL-GRAY: 1 X-MAIL-DELIVERY: 0 X-KSVirus-check: 0 X-ABS-CHECKED: 4 X-RL-SENDER: shawn.lin@rock-chips.com X-FST-TO: linux-kernel@vger.kernel.org X-SENDER-IP: 58.22.7.114 X-LOGIN-NAME: shawn.lin@rock-chips.com X-UNIQUE-TAG: X-ATTACHMENT-NUM: 0 X-DNS-TYPE: 0 Subject: Re: [PATCH 1/2] Documentation: phy: introduce new optional property to specify drive impedance To: =?UTF-8?Q?Heiko_St=c3=bcbner?= References: <1483608682-226716-1-git-send-email-shawn.lin@rock-chips.com> <11505388.Y1Yzh8HsIT@diego> Cc: shawn.lin@rock-chips.com, Kishon Vijay Abraham I , Rob Herring , devicetree@vger.kernel.org, linux-rockchip@lists.infradead.org, Douglas Anderson , linux-kernel@vger.kernel.org From: Shawn Lin Message-ID: <4f26b8e6-494b-72f9-9490-f56f130d8043@rock-chips.com> Date: Fri, 6 Jan 2017 08:44:09 +0800 User-Agent: Mozilla/5.0 (Windows NT 6.3; WOW64; rv:45.0) Gecko/20100101 Thunderbird/45.6.0 MIME-Version: 1.0 In-Reply-To: <11505388.Y1Yzh8HsIT@diego> Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 2017/1/5 19:15, Heiko Stübner wrote: > Hi Shawn, > > Am Donnerstag, 5. Januar 2017, 17:31:21 schrieb Shawn Lin: >> 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. > > In what unit are your 33, 40 etc values? > > It is recommended that properties should specify their unit, see all the > properties ending in "-ma", "-ns" and so on and also > Documentation/devicetree/bindings/property-units.txt > > Also properties should use dashes ("-") not underscores. > > Judging by the second patch, these are Ohm, so combining the above you > probably want > > drive-impedance-ohms > > as property name. > > Also the patch subject is slightly misleading and should probably specify the > rockchip-emmc as well :-) Thanks, will fix them. > > > Heiko > > > -- Best Regards Shawn Lin