| Message ID | 1483608682-226716-1-git-send-email-shawn.lin@rock-chips.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
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@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 > 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 :-) Heiko
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@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 >> 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 > > >
On Thu, Jan 05, 2017 at 05:31:21PM +0800, Shawn Lin wrote: > 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@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 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. Needs a vendor prefix. Don't use '_'. And needs unit suffix (-ohms). > + > Example: > > > -- > 1.9.1 > >
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. + Example:
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@rock-chips.com> --- Documentation/devicetree/bindings/phy/rockchip-emmc-phy.txt | 5 +++++ 1 file changed, 5 insertions(+)