From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S941372AbcJaL7Q (ORCPT ); Mon, 31 Oct 2016 07:59:16 -0400 Received: from mailout2.samsung.com ([203.254.224.25]:47063 "EHLO mailout2.samsung.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S941333AbcJaL7N (ORCPT ); Mon, 31 Oct 2016 07:59:13 -0400 X-AuditID: cbfee61b-f793d6d000005a2a-d2-5817320ee649 Subject: Re: [RFC 1/2] mmc: sdhci: dt: Add device tree properties sdhci-caps and sdhci-caps-mask To: Ulf Hansson , Zach Brown References: <1477425538-3315-1-git-send-email-zach.brown@ni.com> <1477425538-3315-2-git-send-email-zach.brown@ni.com> Cc: Adrian Hunter , Rob Herring , Mark Rutland , linux-mmc , "devicetree@vger.kernel.org" , "linux-kernel@vger.kernel.org" From: Jaehoon Chung Message-id: <6031045c-0eb2-7bea-1efd-874dade0f009@samsung.com> Date: Mon, 31 Oct 2016 20:59:10 +0900 User-Agent: Mozilla/5.0 (X11; Linux i686; rv:45.0) Gecko/20100101 Thunderbird/45.3.0 MIME-version: 1.0 In-reply-to: Content-type: text/plain; charset=utf-8 Content-transfer-encoding: 7bit X-Brightmail-Tracker: H4sIAAAAAAAAA+NgFtrBIsWRmVeSWpSXmKPExsVy+t9jQV0+I/EIg4/7RC1OPlnDZjH/yDlW i8u75rBZHPnfz2ix9PpFJovWvUfYLY6vDbd4tT/OgcNjzbw1jB6L97xk8ti0qpPN4861PWwe 189sZ/L4vEkugC3KzSYjNTEltUghNS85PyUzL91WKTTETddCSSEvMTfVVilC1zckSEmhLDGn FMgzMkADDs4B7sFK+nYJbhmnn7xiL1goVXF+4X/2BsZZol2MnBwSAiYSh1//YoewxSQu3FvP BmILCcxilLi42qWLkQvIfsAosf/MdKYuRg4OYYEkiY2LHUBqRAQ8JFqXvmCHqJnEJPHlxldG kASzwEwmiZnNyiA2m4COxPZvx8F6eQXsJFoaBUDCLAKqEn/nXGIFCYsKhEk8b3QCCfMKCEr8 mHyPBcTmFAiWONc4iR2khFlAXWLKlFyI4fISm9e8ZZ7ACHQiQscshKpZSKoWMDKvYpRILUgu KE5KzzXKSy3XK07MLS7NS9dLzs/dxAiOtWfSOxgP73I/xCjAwajEw7sgSixCiDWxrLgy9xCj BAezkgivv6F4hBBvSmJlVWpRfnxRaU5q8SFGU6AvJjJLiSbnA9NAXkm8oYm5ibmxgYW5paWJ kZI4b+PsZ+FCAumJJanZqakFqUUwfUwcnFINjKK7GSLm8XuJfDTfvzigy6xsZnxSkYiR5/K3 vExF85dsVAw3ss/Y9+9qUHHql4k3jQo/iJz0E5xfeXzJ3HClvnPdW7luJm7cHRYcezVwZbWu nVj2i0nJ1yudCp4Fv7U0WsG3U0wgx93tZmKe5+vctzeUTvO09NewzN5+103DQmJ3782QOVpf lViKMxINtZiLihMBNcH+WMsCAAA= X-MTR: 20000000000000000@CPGS Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 10/28/2016 05:12 PM, Ulf Hansson wrote: > On 25 October 2016 at 21:58, Zach Brown wrote: >> On some systems the sdhci capabilty registers are incorrect for one >> reason or another. >> >> The sdhci-caps-mask property specifies which bits in the registers >> are incorrect and should be turned off before using sdhci-caps to turn >> on bits. >> >> The sdhci-caps property specifies which bits should be turned on. >> >> Signed-off-by: Zach Brown >> --- >> Documentation/devicetree/bindings/mmc/mmc.txt | 7 +++++++ >> 1 file changed, 7 insertions(+) >> >> diff --git a/Documentation/devicetree/bindings/mmc/mmc.txt b/Documentation/devicetree/bindings/mmc/mmc.txt >> index 8a37782..1415aa0 100644 >> --- a/Documentation/devicetree/bindings/mmc/mmc.txt >> +++ b/Documentation/devicetree/bindings/mmc/mmc.txt > > The bindings in this document are common mmc DT bindings, not bindings > specific to a mmc controller. > > So unless these bindings are applicable for another controller than > sdhci, I suggest we create a new file to document these. > How about Documentation/devicetree/bindings/mmc/sdhci.txt? > >> @@ -52,6 +52,13 @@ Optional properties: >> - no-sdio: controller is limited to send sdio cmd during initialization >> - no-sd: controller is limited to send sd cmd during initialization >> - no-mmc: controller is limited to send mmc cmd during initialization >> +- sdhci-caps-mask: The sdhci capabilities registers are incorrect. This 64bit > > /s/registers/register > > This applies to some more places below as well. > >> + property corresponds to the bits in the sdhci capabilty registers. If the bit >> + is on in the mask then the bit is incorrect in the registers and should be >> + turned off. >> +- sdhci-caps: The sdhci capabilities registers are incorrect. This 64bit >> + property corresponds to the bits in the sdhci capability registers. If the >> + bit is on in the property then the bit should be on in the reigsters. > > /s/reigsters/register > >> >> *NOTE* on CD and WP polarity. To use common for all SD/MMC host controllers line >> polarity properties, we have to fix the meaning of the "normal" and "inverted" >> -- >> 2.7.4 >> > > Overall, I like this idea as it gives us good flexibility. Thus it > should avoid us to having to add any further new similar "sdhci broken > cap" DT binding. We could also decide to start deprecate some of the > existing sdhci bindings, if we think that makes sense. > > The downside is that we get a "magic" hex value in the dts. Although, > people could address this issue by providing some comments about what > the bits it means in the dts files themselves. I think it's not good about getting "magic" hex value. In my experience, it's too difficult what bits means and calculate.. Because some people who i know had already used like this.(locally..) It needs to consider this...otherwise..it should become really complex magic code. Best Regards, Jaehoon Chung > > Let's see what Rob thinks about this. > > Kind regards > Uffe > -- > To unsubscribe from this list: send the line "unsubscribe linux-mmc" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html > > >