On Mon, 2020-03-23 at 16:00 -0600, Rob Herring wrote:

On Wed, Mar 11, 2020 at 03:40:29PM +0800, Jitao Shi wrote:

quoted

Add a property to control mipi tx drive current:
"drive-strength-microamp"

Signed-off-by: Jitao Shi <redacted>
---
 .../devicetree/bindings/display/mediatek/mediatek,dsi.txt     | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/Documentation/devicetree/bindings/display/mediatek/mediatek,dsi.txt b/Documentation/devicetree/bindings/display/mediatek/mediatek,dsi.txt
index a19a6cc375ed..d501f9ff4b1f 100644
--- a/Documentation/devicetree/bindings/display/mediatek/mediatek,dsi.txt
+++ b/Documentation/devicetree/bindings/display/mediatek/mediatek,dsi.txt

@@ -33,6 +33,9 @@ Required properties:
 - #clock-cells: must be <0>;
 - #phy-cells: must be <0>.
 
+Optional properties:
+- drive-strength-microamp: adjust driving current, should be 1 ~ 0xF

TBC, 1-0xf is in units of microamps? So a max drive strength of 15uA? 
Seems a bit low.

The minimum amp is 3000 macroamps,  step is 200macroamps.
So the drive current is 3000 + 200 * drive-strength-microamp amps.

I will update "drive-strength-microamp" define next version.

BR
Jitao

quoted

+
 Example:
 
 mipi_tx0: mipi-dphy@10215000 {

@@ -42,6 +45,7 @@ mipi_tx0: mipi-dphy@10215000 {
 	clock-output-names = "mipi_tx0_pll";
 	#clock-cells = <0>;
 	#phy-cells = <0>;
+	drive-strength-microamp = <0x8>;
 };
 
 dsi0: dsi@1401b000 {

-- 
2.21.0

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