Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752517AbcCGJgi (ORCPT ); Mon, 7 Mar 2016 04:36:38 -0500 Received: from lucky1.263xmail.com ([211.157.147.131]:58907 "EHLO lucky1.263xmail.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751938AbcCGJg3 (ORCPT ); Mon, 7 Mar 2016 04:36:29 -0500 X-263anti-spam: KSV:0; X-MAIL-GRAY: 1 X-MAIL-DELIVERY: 0 X-KSVirus-check: 0 X-ABS-CHECKED: 4 X-ADDR-CHECKED: 0 X-RL-SENDER: shawn.lin@rock-chips.com X-FST-TO: shawn.lin@kernel-upstream.org X-SENDER-IP: 58.22.7.114 X-LOGIN-NAME: shawn.lin@rock-chips.com X-UNIQUE-TAG: <06603ec5603c027e0e3566622ce08b06> X-ATTACHMENT-NUM: 0 X-DNS-TYPE: 0 Subject: Re: [PATCH 1/2] Documentation: synopsys-dw-mshc: add binding for resets To: Jaehoon Chung , Guodong Xu , robh+dt@kernel.org, pawel.moll@arm.com, mark.rutland@arm.com, ijc+devicetree@hellion.org.uk, galak@codeaurora.org, ulf.hansson@linaro.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, linux-mmc@vger.kernel.org References: <1457254062-22677-1-git-send-email-guodong.xu@linaro.org> <56DCD11E.5000901@samsung.com> Cc: shawn.lin@rock-chips.com, shawn.lin@kernel-upstream.org From: Shawn Lin Message-ID: <56DD4B79.2090509@rock-chips.com> Date: Mon, 7 Mar 2016 17:35:53 +0800 User-Agent: Mozilla/5.0 (Windows NT 6.3; WOW64; rv:38.0) Gecko/20100101 Thunderbird/38.6.0 MIME-Version: 1.0 In-Reply-To: <56DCD11E.5000901@samsung.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2255 Lines: 66 Hi Jaehoon, On 2016/3/7 8:53, Jaehoon Chung wrote: > Hi Goudong, > > On 03/06/2016 05:47 PM, Guodong Xu wrote: >> Add resets property to synopsys-dw-mshc bindings. It is intended to >> represent the hardware reset signal present internally in some host >> controller IC designs. >> >> See Documentation/devicetree/bindings/reset/reset.txt for details. >> >> Signed-off-by: Guodong Xu >> Acked-by: Rob Herring >> --- >> Documentation/devicetree/bindings/mmc/synopsys-dw-mshc.txt | 4 ++++ >> 1 file changed, 4 insertions(+) >> >> diff --git a/Documentation/devicetree/bindings/mmc/synopsys-dw-mshc.txt b/Documentation/devicetree/bindings/mmc/synopsys-dw-mshc.txt >> index 8636f5a..4e00e85 100644 >> --- a/Documentation/devicetree/bindings/mmc/synopsys-dw-mshc.txt >> +++ b/Documentation/devicetree/bindings/mmc/synopsys-dw-mshc.txt >> @@ -39,6 +39,10 @@ Required Properties: >> >> Optional properties: >> >> +* resets: phandle + reset specifier pair, intended to represent hardware >> + reset signal present internally in some host controller IC designs. >> + See Documentation/devicetree/bindings/reset/reset.txt for details. > > Is this reset property for common dwmmc IP controller? I think so. By discussion with my ASIC team, it's provided by synopsys. From dw_mmc databook version 270a, section 3.2.5, FBE Scenarios: An FBE occurs due to an AHB error response on the AHB bus. This is a system error, so the software driver should not perform any further programming to the DWC_mobile_storage. The only recovery mechanism from such scenarios is to do one of the following: ■ Issue a hard reset by asserting the reset_n signal ■ Do a program controller reset by writing to the CTRL[0] register the reset_n signal can be used to reset all the internal logic block with dwmmc and reset the register value to default stat. Note: reset_n is a internal signal, which is diff from rst_n for mmc hw reset. (refer to databook section 5.2 Signal Descriptions, table 5-1) > > Best Regards, > Jaehoon Chung > >> + >> * clocks: from common clock binding: handle to biu and ciu clocks for the >> bus interface unit clock and the card interface unit clock. >> >> > > > > -- Best Regards Shawn Lin