From mboxrd@z Thu Jan 1 00:00:00 1970 From: Krzysztof Kozlowski Subject: Re: [PATCH 3/3] ARM: dts: exynos5422-odroidxu3: Added UHS-I bus speed support Date: Wed, 14 Oct 2015 10:52:55 +0900 Message-ID: <561DB577.8080808@samsung.com> References: <1444578364-1384-1-git-send-email-linux.amoon@gmail.com> <1444578364-1384-3-git-send-email-linux.amoon@gmail.com> <561B48B7.1040201@samsung.com> <561C4CEE.3050905@samsung.com> <561C7DF1.6000609@samsung.com> <561D9ACE.6050103@samsung.com> <561DACC6.9040209@samsung.com> <561DB290.5070903@samsung.com> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit Return-path: In-reply-to: <561DB290.5070903@samsung.com> Sender: linux-samsung-soc-owner@vger.kernel.org To: Jaehoon Chung , Alim Akhtar Cc: Anand Moon , Kukjin Kim , Javier Martinez Canillas , Lukasz Majewski , "devicetree@vger.kernel.org" , "linux-arm-kernel@lists.infradead.org" , "linux-samsung-soc@vger.kernel.org" , Linux Kernel , Douglas Anderson List-Id: devicetree@vger.kernel.org On 14.10.2015 10:40, Jaehoon Chung wrote: > On 10/14/2015 10:15 AM, Krzysztof Kozlowski wrote: >> On 14.10.2015 10:06, Alim Akhtar wrote: >>> +Doug >>> Hello, >>> AFAIR, dw_mmc host controller does support UHS-I [1], specially SDR50 >>> and SDR104 modes. >>> >>> [1]: http://www.spinics.net/lists/linux-mmc/msg28186.html >>> >>> What I remember is, one need to set "broken-cd" property also in order >>> to make it work because of the vqmmc and vmmc connection on board. I >>> didn't find the link right now, but you can search on the web, there >>> was a long discussion about handling this. >>> Have not checked it recently, so not sure if this got broken somehow. >>> >> >> Please, don't top post. >> >> I am not a SD/MMC specialist (I do not feel enough confident in its >> internals) but the datasheet for 5422 does not mention UHS. However it >> mentions "High Speed DDR Mode with 200 MHz clock rate (HS400)". This >> does not look like UHS... > > You're right. It's not UHS mode. it mentions eMMC's HS400 mode. > UHS and HS400 are difference mode. > > eMMC mode are supported > >> https://www.sdcard.org/developers/overview/bus_speed/ >> This of course is not a definite proof that 5422 does not support UHS. I >> am just saying that I couldn't find any information that *it does*. > > Well, I think you want to know whether it supported or not. > Then you can find the information at User manual. > In mobile storage part of User manual, it described the overview. > Mobile storage host supports these specification: > - Secure Digital memory (SD memory version 3.0) > - Secure Digital I/O SDIO (SDIO version 3.0) > - etc... > > SD3.0 is supported UHS-I mode. > If user manual of exynos5422 is mentioned this specification, it should be supported UHS-I mode. Thanks! Indeed datasheet mentions that supported SD and SDIO is version 3.0 (not 3.01... which seems irrelevant because 3.0 introduced UHS-I, right?). Best regards, Krzysztof