From mboxrd@z Thu Jan 1 00:00:00 1970 From: Zach Brown Subject: [RFC 1/2] sdhci: Add device tree property sd-broken-highspeed Date: Fri, 23 Sep 2016 15:01:08 -0500 Message-ID: <1474660869-15532-2-git-send-email-zach.brown@ni.com> References: <1474660869-15532-1-git-send-email-zach.brown@ni.com> Return-path: In-Reply-To: <1474660869-15532-1-git-send-email-zach.brown@ni.com> Sender: linux-mmc-owner@vger.kernel.org To: ulf.hansson@linaro.org Cc: adrian.hunter@intel.com, robh+dt@kernel.org, mark.rutland@arm.com, linux-mmc@vger.kernel.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, zach.brown@ni.com List-Id: devicetree@vger.kernel.org Certain board configurations can make highspeed malfunction due to timing issues. In these cases a way is needed to force the controller and card into standard speed even if they otherwise appear to be capable of highspeed. The sd-broken-highspeed property will let the sdhci driver know that highspeed will not work. Signed-off-by: Zach Brown --- Documentation/devicetree/bindings/mmc/mmc.txt | 2 ++ 1 file changed, 2 insertions(+) diff --git a/Documentation/devicetree/bindings/mmc/mmc.txt b/Documentation/devicetree/bindings/mmc/mmc.txt index 8a37782..59332ea 100644 --- a/Documentation/devicetree/bindings/mmc/mmc.txt +++ b/Documentation/devicetree/bindings/mmc/mmc.txt @@ -52,6 +52,8 @@ 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 +- sd-broken-highspeed: Highspeed is broken, even if the controller and card + themselves claim they support highspeed. *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