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authorNicolas Ferre <nicolas.ferre@microchip.com>2019-10-08 14:34:31 +0200
committerUlf Hansson <ulf.hansson@linaro.org>2019-11-13 16:10:16 +0100
commit5cd41fe89704d4614562363d9051ee8bfdcf1ea1 (patch)
treefd927636ae39ebbe6aa9871193f82ecab373d41f /Documentation/devicetree
parent61a14e5299bd526c30c00918f7195a89547c8667 (diff)
dt-bindings: sdhci-of-at91: add the microchip,sdcal-inverted property
Add the specific microchip,sdcal-inverted property to at91 sdhci device binding. This optional property describes how the SoC SDCAL pin is connected. It could be handled at SiP, SoM or board level. This property read by at91 sdhci driver will allow to put in place a software workaround that would reduce power consumption. Signed-off-by: Nicolas Ferre <nicolas.ferre@microchip.com> Reviewed-by: Rob Herring <robh@kernel.org> Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Diffstat (limited to 'Documentation/devicetree')
-rw-r--r--Documentation/devicetree/bindings/mmc/sdhci-atmel.txt5
1 files changed, 5 insertions, 0 deletions
diff --git a/Documentation/devicetree/bindings/mmc/sdhci-atmel.txt b/Documentation/devicetree/bindings/mmc/sdhci-atmel.txt
index 1b662d7171a0..503c6dbac1b2 100644
--- a/Documentation/devicetree/bindings/mmc/sdhci-atmel.txt
+++ b/Documentation/devicetree/bindings/mmc/sdhci-atmel.txt
@@ -9,6 +9,11 @@ Required properties:
- clocks: Phandlers to the clocks.
- clock-names: Must be "hclock", "multclk", "baseclk";
+Optional properties:
+- microchip,sdcal-inverted: when present, polarity on the SDCAL SoC pin is
+ inverted. The default polarity for this signal is described in the datasheet.
+ For instance on SAMA5D2, the pin is usually tied to the GND with a resistor
+ and a capacitor (see "SDMMC I/O Calibration" chapter).
Example: