[PATCH 1/2] Documentation: phy: introduce new optional property to specify drive impedance
shawn.lin at rock-chips.com
Thu Jan 5 16:44:09 PST 2017
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 at rock-chips.com>
>> 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
>> +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
> Also properties should use dashes ("-") not underscores.
> Judging by the second patch, these are Ohm, so combining the above you
> probably want
> as property name.
> Also the patch subject is slightly misleading and should probably specify the
> rockchip-emmc as well :-)
Thanks, will fix them.
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