On 2017/1/5 19:15, Heiko Stübner wrote:
Hi Shawn,
Am Donnerstag, 5. Januar 2017, 17:31:21 schrieb Shawn Lin:
We need to modify the drive impedance according to the
different hardware condition. So let's expose this to
the DT.
Signed-off-by: Shawn Lin <shawn.lin@xxxxxxxxxxxxxx>
---
Documentation/devicetree/bindings/phy/rockchip-emmc-phy.txt | 5 +++++
1 file changed, 5 insertions(+)
diff --git a/Documentation/devicetree/bindings/phy/rockchip-emmc-phy.txt
b/Documentation/devicetree/bindings/phy/rockchip-emmc-phy.txt index
e3ea557..731aeb9 100644
--- a/Documentation/devicetree/bindings/phy/rockchip-emmc-phy.txt
+++ b/Documentation/devicetree/bindings/phy/rockchip-emmc-phy.txt
@@ -14,6 +14,11 @@ specified by name:
access to it), it is strongly suggested.
- clocks: Should have a phandle to the card clock exported by the SDHCI
driver.
+Optional Properties:
+- drive_impedance: Must be one of 33, 40, 50, 66, 100. This property allows
+ different boards to specify their own drive impedance depending on the
+ hardware condition.
In what unit are your 33, 40 etc values?
It is recommended that properties should specify their unit, see all the
properties ending in "-ma", "-ns" and so on and also
Documentation/devicetree/bindings/property-units.txt
Also properties should use dashes ("-") not underscores.
Judging by the second patch, these are Ohm, so combining the above you
probably want
drive-impedance-ohms
as property name.
Also the patch subject is slightly misleading and should probably specify the
rockchip-emmc as well :-)
Thanks, will fix them.
Heiko
--
Best Regards
Shawn Lin
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