[PATCH V2 4/6] DT: add binding for mxs on-chip regulators

[Stefan Wahren]

Hello Juergen,

> Jürgen Borleis <jbe at pengutronix.de> hat am 4. Mai 2015 um 15:51 geschrieben:
>
>
> Hi Stefan,
>
> for the i.MX23 the regulator daisy chain looks a little bit different:
>
> +------------+     VDD5V  +---------+  VDDIO
> | DC-DC      |   +--------> LINREG  +--------->+
> |            |            | VDDIO   |          |
> |            |            +---------+          |
> | DCDC_VDDIO +->-+-----------------------------+
> |            |   |
> |            |   | VDDIO  +---------+ VDDMEM
> |            |   +--------> LINREG  +--------->
> |            |   |        | VDDMEM  |
> |            |   |        +---------+
> |            |   | VDDIO  +---------+  VDDA
> |            |   +--------> LINREG  +--------->+
> |            |            | VDDA    |          |
> |            |            +---------+          |
> | DCDC_VDDA  +->-+-----------------------------+
> |            |   | VDDA   +---------+  VDDD
> |            |   +--------> LINREG  +--------->+
> |            |            | VDDD    |          |
> |            |            +---------+          |
> | DCDC_VDDD  +->-------------------------------+
> +------------+                                 |
>                                                v

damn! I didn't noticed that VDDMEM is powered by VDDIO and VDD1P5 is powered by
VDDA. Thank you very much.

>From my understanding VDDMEM and VDD1P5 describe the same regulator function
(provides power to external memory such as SDRAM and mDDR which doesn't fit to
VDDD, VDDIO or VDDA). But the usage of
the name is not consistent across the documentation:
                   
                  | i.MX23 | i.MX28 
------------------------------------
Application note  | VDDMEM | VDD1P5
Reference manual  | VDDMEM | VDDMEM
Data sheet        | -      | VDD1P5

I would suggest to use VDDMEM, because the registers are always called HW_VDDMEM
(for both SoCs).

I think we have 3 options here:

a) add the regulator daisy chain for the i.MX23 too
b) remove VDD1P5 from the i.MX28 diagram so it would fit for both again
c) remove the diagram complete

I would prefer option b. What's your opinion?

>
> Regards,
> Juergen

Best regards
Stefan