Re: [PATCH v2 2/2] arm: dts: k3-am642-evm/sk: Enable OSPI support in SPL

[Jon Humphreys <j-humphreys@ti.com>]

Tom Rini <trini@konsulko.com> writes:

> On Sat, Feb 24, 2024 at 11:34:36AM -0600, Jon Humphreys wrote:
>> Tom Rini <trini@konsulko.com> writes:
>> 
>> > On Fri, Feb 23, 2024 at 06:17:02PM -0600, Jonathan Humphreys wrote:
>> >> Add bootph DT tags to enable OSPI in SPL.
>> >> Set OSPI regs for R5 SPL to address OSPI's boot region.
>> >> 
>> >> Signed-off-by: Jonathan Humphreys <j-humphreys@ti.com>
>> >> ---
>> >>  arch/arm/dts/k3-am642-evm-u-boot.dtsi | 16 ++++++++++++++++
>> >>  arch/arm/dts/k3-am642-r5-evm.dts      |  5 +++++
>> >>  arch/arm/dts/k3-am642-r5-sk.dts       |  5 +++++
>> >>  arch/arm/dts/k3-am642-sk-u-boot.dtsi  | 16 ++++++++++++++++
>> >>  4 files changed, 42 insertions(+)
>> >> 
>> >> diff --git a/arch/arm/dts/k3-am642-evm-u-boot.dtsi b/arch/arm/dts/k3-am642-evm-u-boot.dtsi
>> >> index b843078243..60b219c0be 100644
>> >> --- a/arch/arm/dts/k3-am642-evm-u-boot.dtsi
>> >> +++ b/arch/arm/dts/k3-am642-evm-u-boot.dtsi
>> >> @@ -182,3 +182,19 @@
>> >>  &cpsw_port2 {
>> >>  	status = "disabled";
>> >>  };
>> >> +
>> >> +&ospi0_pins_default {
>> >> +	bootph-all;
>> >> +};
>> >> +
>> >> +&fss {
>> >> +	bootph-all;
>> >> +};
>> >> +
>> >> +&ospi0 {
>> >> +	bootph-all;
>> >> +
>> >> +	flash@0 {
>> >> +		bootph-all;
>> >> +	};
>> >> +};
>> >
>> > So this gets back to what I was asking in the first series, is this
>> > needed in SPL or full U-Boot as well? The bootph-* properties are
>> > supposed to be transitive, but originally the tooling didn't handle this
>> > and now the tooling handles SPL but not full U-Boot. Which also brings
>> > back the is this _needed_ question and is bootph-all right, rather than
>> > just the big hammer?
>> >
>> By "this", are you referring to the original phypattern partition nodes,
>> or the ospi0 node itself?  The partition nodes are not needed at all, so
>> removed.  The ospi node is needed in both SPL and U-Boot.  In that case,
>> using the bootph-all tag is the proper way, correct?
>> 
>> What do you mean by the 'big hammer'?
>> 
>> Please advise and thanks.
>
> So, part of the answer is that the documentation isn't as clear and well
> formatted as I'd like (aside, include/dm/ofnode.h::ofnode_pre_reloc
> comment should be reworded to render better). First, I want to point to
> the schema itself:
> https://github.com/devicetree-org/dt-schema/blob/main/dtschema/schemas/bootph.yaml
> and then next:
> https://docs.u-boot.org/en/latest/develop/driver-model/design.html#pre-relocation-support
>
> And in this case, the "pre" options are a bit less clear as TI platforms
> don't do the TPL->SPL->Full U-Boot dance that others like say Rockchip
> do but instead the Cortex-R/Cortex-A dance for the K3 architecture.
>
> Which gets back to what I was trying to ask. What, functionally,
> requires that property to be present? And then, for the cortex-a
> platforms these should be in the upstream dtb and I forget if you said
> that's in progress for these platforms or not.

Without those properties, the on-board OSPI flash is not available to
u-boot.

There is a separate action to move the bootph properities (not just the
above) to the upstream DT.

>
> -- 
> Tom