Messages in this thread | | | Date | Tue, 20 Jun 2023 09:26:57 +0100 | From | Conor Dooley <> | Subject | Re: [PATCH v3 1/2] dt-bindings: net: motorcomm: Add pad driver strength cfg |
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Hey,
On Tue, Jun 20, 2023 at 11:09:52AM +0800, Guo Samin wrote: > From: Guo Samin <samin.guo@starfivetech.com> > > From: Conor Dooley <conor@kernel.org> > >> On Fri, May 26, 2023 at 05:05:01PM +0800, Samin Guo wrote: > >>> The motorcomm phy (YT8531) supports the ability to adjust the drive > >>> strength of the rx_clk/rx_data, the value range of pad driver > >>> strength is 0 to 7.
> >>> + motorcomm,rx-clk-driver-strength: > >>> + description: drive strength of rx_clk pad. > >>> + $ref: /schemas/types.yaml#/definitions/uint32 > >>> + enum: [ 0, 1, 2, 3, 4, 5, 6, 7 ] > >> > >> I think you should use minimum & maximum instead of these listed out > >> enums.
> > You have also had this comment since v1 & were reminded of it on > >> v2 by Krzysztof: "What do the numbers mean? What are the units? mA?"
> > The good news is that we just got some data about units from Motorcomm. > > Maybe I can post the data show of the unit later after I get the complete data.
> Sorry, haven't updated in a while.
NW chief.
> I just got the detailed data of Driver Strength(DS) from Motorcomm , which applies to both rx_clk and rx_data. > > |----------------------| > | ds map table | > |----------------------| > | DS(3b) | Current (mA)| > |--------|-------------| > | 000 | 1.20 | > | 001 | 2.10 | > | 010 | 2.70 | > | 011 | 2.91 | > | 100 | 3.11 | > | 101 | 3.60 | > | 110 | 3.97 | > | 111 | 4.35 | > |--------|-------------| > > Since these currents are not integer values and have no regularity, > it is not very good to use in the drive/dts in my opinion.
Who says you have to use mA? What about uA?
> Therefore, I tend to continue to use DS(0-7) in dts/driver, and adding > a description of the current value corresponding to DS in dt-bindings.
I think this goes against not putting register values into the dts & that the accurate description of the hardware are the currents.
> Like This: > > + motorcomm,rx-clk-driver-strength: > + description: drive strength of rx_clk pad.
You need "description: |" to preserve the formatting if you add tables, but I don't think that this is a good idea. Put the values in here that describe the hardware (IOW the currents) and then you don't need to have this table.
> + |----------------------| > + | rx_clk ds map table | > + |----------------------| > + | DS(3b) | Current (mA)| > + | 000 | 1.20 | > + | 001 | 2.10 | > + | 010 | 2.70 | > + | 011 | 2.91 | > + | 100 | 3.11 | > + | 101 | 3.60 | > + | 110 | 3.97 | > + | 111 | 4.35 | > + |--------|-------------| > + $ref: /schemas/types.yaml#/definitions/uint32 > + enum: [ 0, 1, 2, 3, 4, 5, 6, 7 ] > + default: 3 > +
> Or use minimum & maximum instead of these listed out enums
With the actual current values, enum rather than min + max.
Cheers, Conor. [unhandled content-type:application/pgp-signature] | |