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[v2,1/3] dt-bindings: mmc: describe new eMMC binding for fixed driver type

Message ID 20171004173920.15232-2-wsa+renesas@sang-engineering.com (mailing list archive)
State New, archived
Headers show

Commit Message

Wolfram Sang Oct. 4, 2017, 5:39 p.m. UTC
Some boards may have to use a certain driver type (or drive strength) to
achieve stable eMMC communication. Describe a binding to set this up via
DT.

Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Acked-by: Rob Herring <robh@kernel.org>
Cc: devicetree@vger.kernel.org
---
Changes since RFC v1:
* rebased to mmc/next based on 4.14-rc3
* proper prefix for subject
* added Rob's ack

 Documentation/devicetree/bindings/mmc/mmc.txt | 3 +++
 1 file changed, 3 insertions(+)
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Patch

diff --git a/Documentation/devicetree/bindings/mmc/mmc.txt b/Documentation/devicetree/bindings/mmc/mmc.txt
index b32ade645ad97c..94a90b49a6925d 100644
--- a/Documentation/devicetree/bindings/mmc/mmc.txt
+++ b/Documentation/devicetree/bindings/mmc/mmc.txt
@@ -53,6 +53,9 @@  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
+- fixed-emmc-driver-type: for non-removable eMMC, enforce this driver type.
+  The value <n> is the driver type as specified in the eMMC specification
+  (table 206 in spec version 5.1).
 
 *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"