Messages in this thread | | | Date | Mon, 29 Sep 2014 13:53:22 +0200 | From | Stefan Wahren <> | Subject | Re: [PATCH 1/2] DT: add binding for mxs regulator |
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Hi Mark,
Am 29.09.2014 um 13:09 schrieb Mark Rutland: > On Sat, Sep 27, 2014 at 01:59:47AM +0100, Stefan Wahren wrote: >> This patch adds the Device tree bindings for the Freescale MXS >> on-chip regulators. >> >> Signed-off-by: Stefan Wahren <stefan.wahren@i2se.com> >> --- >> .../bindings/regulator/mxs-regulator.txt | 36 ++++++++++++++++++++ >> 1 file changed, 36 insertions(+) >> create mode 100644 Documentation/devicetree/bindings/regulator/mxs-regulator.txt >> >> diff --git a/Documentation/devicetree/bindings/regulator/mxs-regulator.txt b/Documentation/devicetree/bindings/regulator/mxs-regulator.txt >> new file mode 100644 >> index 0000000..e3133a4 >> --- /dev/null >> +++ b/Documentation/devicetree/bindings/regulator/mxs-regulator.txt >> @@ -0,0 +1,36 @@ >> +MXS regulators >> + >> +Required node properties: >> +- compatible: Should be "simple-bus" > This does not look like an appropriate use of simple-bus. > > Why do you want the parent node to be a simple-bus?
the current parent node in imx28.dtsi looks like a placeholder for the power sub system:
power: power@80044000 { reg = <0x80044000 0x2000>; status = "disabled"; };
I want to trigger the probing of the child nodes (regulators) without writing a driver for the complete power sub system. The simple-bus avoids that.
Do we need a extra driver?
> >> +- #address-cells: Number of cells required to define regulator register, >> + must be 1 >> +- #size-cells: Number of cells required to define register size, must be 1 > Why must this be the case, given that the child node expects an absolute > physical address?
I need a property to define the control register for the regulators without defining vendor specific properties like "fsl,mxs-control-reg" or something.
> What's wrong with #address-cells = <2>, for example?
Nothing
> >> +- reg: Absolute physical address and size of the register set for the device > Why is this here _and_ in the child node(s)?
The parent of the power node is also a simple bus. I use this to calculate the power status register per offset.
> What is the difference between this node and its children?
The parent node represent the power sub system and the regulators are part of this sub system.
> Can there be more than one sub-node?
In the i.MX28 are at least 4 voltage regulators, 1 current regulator and many more. At first, the driver should implement only 3 voltage regulators (vddd, vdda, vddio).
> Mark. >
Best regards
Stefan
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