diff mbox series

[v3,2/4] dt-bindings: phy: Add a new property drive-impedance-ohm for RK's emmc PHY

Message ID 20190322113456.16324-2-christoph.muellner@theobroma-systems.com (mailing list archive)
State New, archived
Headers show
Series [v3,1/4] phy: rockchip-emmc: Allow to set drive impedance via DTS. | expand

Commit Message

Christoph Muellner March 22, 2019, 11:34 a.m. UTC 
This patch documents the new proprty drive-impedance-ohm for
Rockchip's eMMC PHY node.

Signed-off-by: Christoph Muellner <christoph.muellner@theobroma-systems.com>
Signed-off-by: Philipp Tomsich <philipp.tomsich@theobroma-systems.com>
---
 Documentation/devicetree/bindings/phy/rockchip-emmc-phy.txt | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)
diff mbox series

Patch

diff --git a/Documentation/devicetree/bindings/phy/rockchip-emmc-phy.txt b/Documentation/devicetree/bindings/phy/rockchip-emmc-phy.txt
index e3ea55763b0a..e728786f21e0 100644
--- a/Documentation/devicetree/bindings/phy/rockchip-emmc-phy.txt
+++ b/Documentation/devicetree/bindings/phy/rockchip-emmc-phy.txt
@@ -7,12 +7,15 @@  Required properties:
  - reg: PHY register address offset and length in "general
    register files"
 
-Optional clocks using the clock bindings (see ../clock/clock-bindings.txt),
-specified by name:
+Optional properties:
  - clock-names: Should contain "emmcclk".  Although this is listed as optional
 		(because most boards can get basic functionality without having
 		access to it), it is strongly suggested.
+		See ../clock/clock-bindings.txt for details.
  - clocks: Should have a phandle to the card clock exported by the SDHCI driver.
+ - drive-impedance-ohm: Specifies the drive impedance in Ohm.
+                        Possible values are 33, 40, 50, 66 and 100.
+                        If not set, the default value of 50 will be applied.
 
 Example:
 
@@ -29,6 +32,7 @@  grf: syscon@ff770000 {
 		reg = <0xf780 0x20>;
 		clocks = <&sdhci>;
 		clock-names = "emmcclk";
+		drive-impedance-ohm = <50>;
 		#phy-cells = <0>;
 	};
 };