[PATCH] powerpc/85xx: P2020: Add law_trgt_if property to PCIe DT nodes

[PATCH] powerpc/85xx: P2020: Add law_trgt_if property to PCIe DT nodes

[Pali Rohár]

DT law_trgt_if property defines Local Access Window Target Interface.

Local Access Window Target Interface is used for identifying individual
peripheral and mapping its memory to CPU. Interface id is defined by
hardware itself.

U-Boot uses law_trgt_if DT property in PCIe nodes for configuring memory
mapping of individual PCIe controllers.

Linux kernel fsl_pci.c driver currently does not touch Local Access Window
and expects that U-Boot configures it properly.

Add law_trgt_if property to PCIe DT nodes for P2020. This allows usage of
kernel P2020 PCIe DT nodes in U-Boot. And therefore allows to share P2020
DTS files between Linux kernel and U-Boot.

Signed-off-by: Pali Rohár <pali@kernel.org>
---
 arch/powerpc/boot/dts/fsl/p2020si-post.dtsi | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/arch/powerpc/boot/dts/fsl/p2020si-post.dtsi b/arch/powerpc/boot/dts/fsl/p2020si-post.dtsi
index 884e01bcb243..6345629524fe 100644
--- a/arch/powerpc/boot/dts/fsl/p2020si-post.dtsi
+++ b/arch/powerpc/boot/dts/fsl/p2020si-post.dtsi
@@ -48,6 +48,7 @@
 	bus-range = <0 255>;
 	clock-frequency = <33333333>;
 	interrupts = <26 2 0 0>;
+	law_trgt_if = <2>;
 
 	pcie@0 {
 		reg = <0 0 0 0 0>;
@@ -76,6 +77,7 @@
 	bus-range = <0 255>;
 	clock-frequency = <33333333>;
 	interrupts = <25 2 0 0>;
+	law_trgt_if = <1>;
 
 	pcie@0 {
 		reg = <0 0 0 0 0>;
@@ -105,6 +107,7 @@
 	bus-range = <0 255>;
 	clock-frequency = <33333333>;
 	interrupts = <24 2 0 0>;
+	law_trgt_if = <0>;
 
 	pcie@0 {
 		reg = <0 0 0 0 0>;
-- 
2.20.1

Re: [PATCH] powerpc/85xx: P2020: Add law_trgt_if property to PCIe DT nodes

[Rob Herring]

On Wed, May 4, 2022 at 1:09 PM Pali Rohár <pali@kernel.org> wrote:
>
> DT law_trgt_if property defines Local Access Window Target Interface.

Documentation?

fsl,law-trgt-if would be the preferred form.

> Local Access Window Target Interface is used for identifying individual
> peripheral and mapping its memory to CPU. Interface id is defined by
> hardware itself.

Normally, we avoid instance indices like this, but if it is more than
just documentation convention maybe that's fine.

Rob

Re: [PATCH] powerpc/85xx: P2020: Add law_trgt_if property to PCIe DT nodes

[Pali Rohár]

On Thursday 05 May 2022 10:40:09 Rob Herring wrote:
> On Wed, May 4, 2022 at 1:09 PM Pali Rohár <pali@kernel.org> wrote:
> >
> > DT law_trgt_if property defines Local Access Window Target Interface.
> 
> Documentation?

I was not able to find it :-( So the only documentation for me was the
source code and decoding how it works and how it is used.

> fsl,law-trgt-if would be the preferred form.
> 
> > Local Access Window Target Interface is used for identifying individual
> > peripheral and mapping its memory to CPU. Interface id is defined by
> > hardware itself.
> 
> Normally, we avoid instance indices like this, but if it is more than
> just documentation convention maybe that's fine.
> 
> Rob

It is id defined by HW. Software needs to know how to pair DT node with
address range defined in "ranges" to the correct HW PCIe controller.

Re: [PATCH] powerpc/85xx: P2020: Add law_trgt_if property to PCIe DT nodes

[Michael Ellerman]

On Wed, 4 May 2022 20:08:22 +0200, Pali Rohár wrote:
> DT law_trgt_if property defines Local Access Window Target Interface.
> 
> Local Access Window Target Interface is used for identifying individual
> peripheral and mapping its memory to CPU. Interface id is defined by
> hardware itself.
> 
> U-Boot uses law_trgt_if DT property in PCIe nodes for configuring memory
> mapping of individual PCIe controllers.
> 
> [...]

Applied to powerpc/next.

[1/1] powerpc/85xx: P2020: Add law_trgt_if property to PCIe DT nodes
      https://git.kernel.org/powerpc/c/1f00b5ab992c122c51bc37662b3b4df5963462f3

cheers

Re: [PATCH] powerpc/85xx: P2020: Add law_trgt_if property to PCIe DT nodes

[Rob Herring]

On Fri, Jul 29, 2022 at 7:17 AM Michael Ellerman
<patch-notifications@ellerman.id.au> wrote:
>
> On Wed, 4 May 2022 20:08:22 +0200, Pali Rohár wrote:
> > DT law_trgt_if property defines Local Access Window Target Interface.
> >
> > Local Access Window Target Interface is used for identifying individual
> > peripheral and mapping its memory to CPU. Interface id is defined by
> > hardware itself.
> >
> > U-Boot uses law_trgt_if DT property in PCIe nodes for configuring memory
> > mapping of individual PCIe controllers.
> >
> > [...]
>
> Applied to powerpc/next.
>
> [1/1] powerpc/85xx: P2020: Add law_trgt_if property to PCIe DT nodes
>       https://git.kernel.org/powerpc/c/1f00b5ab992c122c51bc37662b3b4df5963462f3

Why? Minimally, it needs a vendor prefix and s/_/-/ as I commented.

Rob

Re: [PATCH] powerpc/85xx: P2020: Add law_trgt_if property to PCIe DT nodes

[Michael Ellerman]

Rob Herring <robh+dt@kernel.org> writes:
> On Fri, Jul 29, 2022 at 7:17 AM Michael Ellerman
> <patch-notifications@ellerman.id.au> wrote:
>>
>> On Wed, 4 May 2022 20:08:22 +0200, Pali Rohár wrote:
>> > DT law_trgt_if property defines Local Access Window Target Interface.
>> >
>> > Local Access Window Target Interface is used for identifying individual
>> > peripheral and mapping its memory to CPU. Interface id is defined by
>> > hardware itself.
>> >
>> > U-Boot uses law_trgt_if DT property in PCIe nodes for configuring memory
>> > mapping of individual PCIe controllers.
>> >
>> > [...]
>>
>> Applied to powerpc/next.
>>
>> [1/1] powerpc/85xx: P2020: Add law_trgt_if property to PCIe DT nodes
>>       https://git.kernel.org/powerpc/c/1f00b5ab992c122c51bc37662b3b4df5963462f3
>
> Why? Minimally, it needs a vendor prefix and s/_/-/ as I commented.

OK. I misread your "maybe that's fine" as approval.

Pali can you send a fixup patch please?

cheers

Re: [PATCH] powerpc/85xx: P2020: Add law_trgt_if property to PCIe DT nodes

[Pali Rohár]

On Monday 01 August 2022 13:38:32 Michael Ellerman wrote:
> Rob Herring <robh+dt@kernel.org> writes:
> > On Fri, Jul 29, 2022 at 7:17 AM Michael Ellerman
> > <patch-notifications@ellerman.id.au> wrote:
> >>
> >> On Wed, 4 May 2022 20:08:22 +0200, Pali Rohár wrote:
> >> > DT law_trgt_if property defines Local Access Window Target Interface.
> >> >
> >> > Local Access Window Target Interface is used for identifying individual
> >> > peripheral and mapping its memory to CPU. Interface id is defined by
> >> > hardware itself.
> >> >
> >> > U-Boot uses law_trgt_if DT property in PCIe nodes for configuring memory
> >> > mapping of individual PCIe controllers.
> >> >
> >> > [...]
> >>
> >> Applied to powerpc/next.
> >>
> >> [1/1] powerpc/85xx: P2020: Add law_trgt_if property to PCIe DT nodes
> >>       https://git.kernel.org/powerpc/c/1f00b5ab992c122c51bc37662b3b4df5963462f3
> >
> > Why? Minimally, it needs a vendor prefix and s/_/-/ as I commented.
> 
> OK. I misread your "maybe that's fine" as approval.
> 
> Pali can you send a fixup patch please?
> 
> cheers

No I cannot. This is how this property is used by bootloaders for at
least 10 years. There are underlines (not hyphens) and there is no
vendor prefix.