On Tue, Mar 12, 2019 at 9:41 PM Stanley Chu <stanley.chu@xxxxxxxxxxxx> wrote: > > Hi Rob, > > On Tue, 2019-03-12 at 21:31 +0800, Rob Herring wrote: > > On Wed, Feb 27, 2019 at 03:23:10PM +0800, Stanley Chu wrote: > > > Add UFS and UFS PHY node document for Mediatek SoC chips. > > > > > > Signed-off-by: Stanley Chu <stanley.chu@xxxxxxxxxxxx> > > > --- > > > .../devicetree/bindings/ufs/ufs-mediatek.txt | 47 +++++++++++++++++++ > > > 1 file changed, 47 insertions(+) > > > create mode 100644 Documentation/devicetree/bindings/ufs/ufs-mediatek.txt > > > > > > diff --git a/Documentation/devicetree/bindings/ufs/ufs-mediatek.txt b/Documentation/devicetree/bindings/ufs/ufs-mediatek.txt > > > new file mode 100644 > > > index 000000000000..5fc985928b3e > > > --- /dev/null > > > +++ b/Documentation/devicetree/bindings/ufs/ufs-mediatek.txt > > > @@ -0,0 +1,47 @@ > > > +* Mediatek Universal Flash Storage (UFS) Host Controller > > > + > > > +UFS nodes are defined to describe on-chip UFS hardware macro. > > > +Each UFS Host Controller should have its own node. > > > + > > > +To bind UFS PHY with UFS host controller, the controller node should > > > +contain a phandle reference to UFS M-PHY node. > > > + > > > +Required properties for UFS nodes: > > > +- compatible : Compatible list, contains the following controller: > > > + "mediatek,ufshci" > > > > Needs an SoC specific compatible string. > > Will add. > > > > > > +- reg : Address and length of the UFS register set. > > > +- interrupt-parent : Interrupt device. > > > > Drop this. It is implied or may be in a parent node. > > Will remove it. > > > > > > +- phys : phandle to m-phy. > > > +- clocks : List of phandle and clock specifier pairs. > > > +- clock-names : List of clock input name strings sorted in the same > > > + order as the clocks property. "ufs-clk" is mandatory. > > > +- freq-table-hz : Array of <min max> operating frequencies stored in the same > > > + order as the clocks property. If this property is not > > > + defined or a value in the array is "0" then it is assumed > > > + that the frequency is set by the parent clock or a > > > + fixed rate clock source. > > > +- vcc-supply : Power to the UFS device. > > > +- vcc-fixed-regulator: Specify that vcc-supply is a fixed regulator. > > > > Why is this needed? The driver could query the voltage range of the > > regulator or you could check the regulator node. > > Both ufshcd-pltfrm.txt and ufshcd-pltfrm.c driver allow > > - <name>-fixed-regulator : boolean property specifying that > <name>-supply is a fixed regulator. > > Our vcc does not require further initializatio, so is it OK here or > shall we also modify both ufshcd-pltfrm dt-bindings document and ufs > driver to avoid using it ? There are no users of that property in tree and doesn't look like adding it was ever reviewed. We have standard ways to handle this and don't need a custom property. Rob
