Hi Rob,
On 4/12/23 15:39, Rob Herring wrote:
On Tue, Apr 11, 2023 at 04:22:37PM +0200, Johannes Zink wrote:
Hi Krzystof,
thank you for your explanations. As I'm still quite new to writing
bindings, I still have some questions:
On Fri, 2023-04-07 at 11:03 +0200, Krzysztof Kozlowski wrote:
On 05/04/2023 14:14, Johannes Zink wrote:
Hi Krysztof,
thanks for your review, please find my questions below.
On Wed, 2023-04-05 at 13:51 +0200, Krzysztof Kozlowski wrote:
[snip]
A phandle to the regulator for USB VBUS.
+ fsl,phy-tx-vref-tune:
+ description:
+ HS DC Voltage level adjustment
"Level" in what units?
The datasheet just shows percent, ranging from -6 to +24%, in 2%
increments. What unit would you suggest?
percent
https://github.com/devicetree-org/dt-schema/blob/main/dtschema/schemas/property-units.yaml
I am still a bit confused how to use this properly. How can I restrict
the values to multiples of 2 in order to avoid illegal values?
At the moment the only thing I could come up with is something like
fsl,phy-tx-vref-tune-percent:
description: |
Adjusts the high-speed DC level voltage
$ref: /schemas/types.yaml#/definitions/int32
Note that with standard unit suffixes, you don't need a type.
minimum: -6
maximum: 24
default: 0
Does something like this work? I am not quite sure if I am on the right
track here, especially as this requires a signed int, of which I have
not seen many examples so far.
We'd have to change the type for -percent to signed. That's possible,
but for vendor specific properties there's not much advantage to use
standard units instead of just using the register values directly.
I don't have any objections to that, this is pretty much what I sent in
my v1 patch <20230405112118.1256151-2-j.zink@xxxxxxxxxxxxxx>, but
Krzysztof requested to change the vendor specific properties to use
property-units.
Would something along the lines of the st,trim-hs-current on
Documentation/devicetree/bindings/phy/phy-stm32-usbphyc.yaml be
acceptable (i.e. use an enum and annotate the meaning of the values in
the description)?
I will, nevertheless, try to make the descriptions a bit more verbose in
my v2 (wherever the datasheet gives me proper informations), as
Krzysztof requested.
Best regards
Johannes
Rob
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