From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jaehoon Chung Subject: Re: [PATCH V5 1/2] mmc: dw_mmc: exynos: Support eMMC's HS400 mode Date: Thu, 26 Feb 2015 10:22:28 +0900 Message-ID: <54EE7554.6060506@samsung.com> References: <1422499318-13726-1-git-send-email-alim.akhtar@samsung.com> <1422499318-13726-2-git-send-email-alim.akhtar@samsung.com> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit Return-path: Received: from mailout2.samsung.com ([203.254.224.25]:13261 "EHLO mailout2.samsung.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752925AbbBZBWa (ORCPT ); Wed, 25 Feb 2015 20:22:30 -0500 In-reply-to: Sender: linux-mmc-owner@vger.kernel.org List-Id: linux-mmc@vger.kernel.org To: Rob Herring , Alim Akhtar Cc: "linux-mmc@vger.kernel.org" , "devicetree@vger.kernel.org" , Ulf Hansson , "linux-samsung-soc@vger.kernel.org" , Seungwon Jeon , "chris@printf.net" , Doug Anderson , "kgene@kernel.org" , a.kesavan@samsung.com, alim.akhtar@gmail.com, "linux-arm-kernel@lists.infradead.org" Dear, Rob. On 02/25/2015 11:38 PM, Rob Herring wrote: > On Wed, Jan 28, 2015 at 8:41 PM, Alim Akhtar wrote: >> From: Seungwon Jeon >> >> Implements HS400 mode support for exynos host driver. >> This also include some updates as new mode is added. >> >> Signed-off-by: Seungwon Jeon >> Signed-off-by: Alim Akhtar >> [Alim: addressed review comments] >> --- >> .../devicetree/bindings/mmc/exynos-dw-mshc.txt | 7 + >> drivers/mmc/host/dw_mmc-exynos.c | 185 ++++++++++++++++---- >> drivers/mmc/host/dw_mmc-exynos.h | 19 +- >> drivers/mmc/host/dw_mmc.c | 16 +- >> drivers/mmc/host/dw_mmc.h | 2 + >> 5 files changed, 195 insertions(+), 34 deletions(-) >> >> diff --git a/Documentation/devicetree/bindings/mmc/exynos-dw-mshc.txt b/Documentation/devicetree/bindings/mmc/exynos-dw-mshc.txt >> index ee4fc05..aad9844 100644 >> --- a/Documentation/devicetree/bindings/mmc/exynos-dw-mshc.txt >> +++ b/Documentation/devicetree/bindings/mmc/exynos-dw-mshc.txt >> @@ -36,6 +36,8 @@ Required Properties: >> in transmit mode and CIU clock phase shift value in receive mode for double >> data rate mode operation. Refer notes below for the order of the cells and the >> valid values. >> +* samsung,dw-mshc-hs400-timing: Specifies the value of CIU TX and RX clock phase >> + shift value for hs400 mode operation. > > What are the units? Do you means what is "sumsung,dw-mshci-hs400-timing" unit? It's timing value for eMMC/SD/SDIO clock phase.(It's exynos specific value.) Using timing value can shift the H/W clock phase. If invalid timing value is set, eMMC/SD/SDIO can produce the CRC error. Do you think it can't include into device-tree? I want to know your thinking. let me know, plz. Best Regards, Jaehoon Chung > > Rob > From mboxrd@z Thu Jan 1 00:00:00 1970 From: jh80.chung@samsung.com (Jaehoon Chung) Date: Thu, 26 Feb 2015 10:22:28 +0900 Subject: [PATCH V5 1/2] mmc: dw_mmc: exynos: Support eMMC's HS400 mode In-Reply-To: References: <1422499318-13726-1-git-send-email-alim.akhtar@samsung.com> <1422499318-13726-2-git-send-email-alim.akhtar@samsung.com> Message-ID: <54EE7554.6060506@samsung.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org Dear, Rob. On 02/25/2015 11:38 PM, Rob Herring wrote: > On Wed, Jan 28, 2015 at 8:41 PM, Alim Akhtar wrote: >> From: Seungwon Jeon >> >> Implements HS400 mode support for exynos host driver. >> This also include some updates as new mode is added. >> >> Signed-off-by: Seungwon Jeon >> Signed-off-by: Alim Akhtar >> [Alim: addressed review comments] >> --- >> .../devicetree/bindings/mmc/exynos-dw-mshc.txt | 7 + >> drivers/mmc/host/dw_mmc-exynos.c | 185 ++++++++++++++++---- >> drivers/mmc/host/dw_mmc-exynos.h | 19 +- >> drivers/mmc/host/dw_mmc.c | 16 +- >> drivers/mmc/host/dw_mmc.h | 2 + >> 5 files changed, 195 insertions(+), 34 deletions(-) >> >> diff --git a/Documentation/devicetree/bindings/mmc/exynos-dw-mshc.txt b/Documentation/devicetree/bindings/mmc/exynos-dw-mshc.txt >> index ee4fc05..aad9844 100644 >> --- a/Documentation/devicetree/bindings/mmc/exynos-dw-mshc.txt >> +++ b/Documentation/devicetree/bindings/mmc/exynos-dw-mshc.txt >> @@ -36,6 +36,8 @@ Required Properties: >> in transmit mode and CIU clock phase shift value in receive mode for double >> data rate mode operation. Refer notes below for the order of the cells and the >> valid values. >> +* samsung,dw-mshc-hs400-timing: Specifies the value of CIU TX and RX clock phase >> + shift value for hs400 mode operation. > > What are the units? Do you means what is "sumsung,dw-mshci-hs400-timing" unit? It's timing value for eMMC/SD/SDIO clock phase.(It's exynos specific value.) Using timing value can shift the H/W clock phase. If invalid timing value is set, eMMC/SD/SDIO can produce the CRC error. Do you think it can't include into device-tree? I want to know your thinking. let me know, plz. Best Regards, Jaehoon Chung > > Rob >