diff mbox

[RFC,v10,1/7] dt-bindings: PCI: Add definition of PCIe WAKE# irq and PCI irq

Message ID 20171027072612.26565-2-jeffy.chen@rock-chips.com (mailing list archive)
State New, archived
Delegated to: Bjorn Helgaas
Headers show

Commit Message

Jeffy Chen Oct. 27, 2017, 7:26 a.m. UTC
We are going to handle PCIe WAKE# pin for PCI bus bridges and PCI
devices in the pci core, so add definitions of the optional PCIe
WAKE# pin for PCI bus bridges and PCI devices.

Also add an definition of the optional PCI interrupt pin for PCI
devices to distinguish it from the PCIe WAKE# pin.

Signed-off-by: Jeffy Chen <jeffy.chen@rock-chips.com>
---

Changes in v10: None
Changes in v9:
Add section for PCI devices and rewrite the commit message.

Changes in v8:
Add optional "pci", and rewrite commit message.

Changes in v7: None
Changes in v6: None
Changes in v5:
Move to pci.txt

Changes in v3: None
Changes in v2: None

 Documentation/devicetree/bindings/pci/pci.txt | 8 ++++++++
 1 file changed, 8 insertions(+)

Comments

Brian Norris Oct. 27, 2017, 8:45 p.m. UTC | #1
Hi,

On Fri, Oct 27, 2017 at 03:26:06PM +0800, Jeffy Chen wrote:
> We are going to handle PCIe WAKE# pin for PCI bus bridges and PCI
> devices in the pci core, so add definitions of the optional PCIe
> WAKE# pin for PCI bus bridges and PCI devices.
> 
> Also add an definition of the optional PCI interrupt pin for PCI
> devices to distinguish it from the PCIe WAKE# pin.
> 
> Signed-off-by: Jeffy Chen <jeffy.chen@rock-chips.com>
> ---
> 
> Changes in v10: None
> Changes in v9:
> Add section for PCI devices and rewrite the commit message.
> 
> Changes in v8:
> Add optional "pci", and rewrite commit message.
> 
> Changes in v7: None
> Changes in v6: None
> Changes in v5:
> Move to pci.txt
> 
> Changes in v3: None
> Changes in v2: None
> 
>  Documentation/devicetree/bindings/pci/pci.txt | 8 ++++++++
>  1 file changed, 8 insertions(+)
> 
> diff --git a/Documentation/devicetree/bindings/pci/pci.txt b/Documentation/devicetree/bindings/pci/pci.txt
> index c77981c5dd18..d4406d4e15ad 100644
> --- a/Documentation/devicetree/bindings/pci/pci.txt
> +++ b/Documentation/devicetree/bindings/pci/pci.txt
> @@ -24,3 +24,11 @@ driver implementation may support the following properties:
>     unsupported link speed, for instance, trying to do training for
>     unsupported link speed, etc.  Must be '4' for gen4, '3' for gen3, '2'
>     for gen2, and '1' for gen1. Any other values are invalid.
> +- interrupts: Interrupt specifier for each name in interrupt-names.
> +- interrupt-names: May contains "wakeup" for PCIe WAKE# interrupt.

s/contains/contain/

> +
> +PCI devices have standardized Device Tree bindings:

This line is a little unclear, especially since there *is* an old
documented standard, yet the following text is actually introducing new,
non-standard additions.

> +
> +- interrupts: Interrupt specifier for each name in interrupt-names.
> +- interrupt-names: May contains "wakeup" for PCIe WAKE# interrupt and "pci" for

s/contains/contain/

> +  PCI interrupt.

IMO, since you're trying to augment a standardized binding, you need to
be a lot clearer here. I expect you should mention the existing standard
(that devices may optionally include an 'interrupts' property that
represents the legacy PCI interrupt) and how you're augmenting it (that
additional interrupts can be supported optionally, but they require a
corresponding 'interrupt-names' property).

Also, is this binding only applying either to a host bridge or to
devices? No intermediate bridges or ports? It seems so, but I wanted to
be clear. (And it probably could be extended if needed. Notably, ACPI
has a tree-walk implementation, so if the device itself doesn't have
a wakeup config, it can look into any of its parents.)

Once you fix up the documentation...I suppose this looks like a sane
idea. But I'd like 2nd opinions on this.

Brian
Rob Herring (Arm) Nov. 1, 2017, 9:05 p.m. UTC | #2
On Fri, Oct 27, 2017 at 01:45:17PM -0700, Brian Norris wrote:
> Hi,
> 
> On Fri, Oct 27, 2017 at 03:26:06PM +0800, Jeffy Chen wrote:
> > We are going to handle PCIe WAKE# pin for PCI bus bridges and PCI
> > devices in the pci core, so add definitions of the optional PCIe
> > WAKE# pin for PCI bus bridges and PCI devices.
> > 
> > Also add an definition of the optional PCI interrupt pin for PCI
> > devices to distinguish it from the PCIe WAKE# pin.
> > 
> > Signed-off-by: Jeffy Chen <jeffy.chen@rock-chips.com>
> > ---
> > 
> > Changes in v10: None
> > Changes in v9:
> > Add section for PCI devices and rewrite the commit message.
> > 
> > Changes in v8:
> > Add optional "pci", and rewrite commit message.
> > 
> > Changes in v7: None
> > Changes in v6: None
> > Changes in v5:
> > Move to pci.txt
> > 
> > Changes in v3: None
> > Changes in v2: None
> > 
> >  Documentation/devicetree/bindings/pci/pci.txt | 8 ++++++++
> >  1 file changed, 8 insertions(+)
> > 
> > diff --git a/Documentation/devicetree/bindings/pci/pci.txt b/Documentation/devicetree/bindings/pci/pci.txt
> > index c77981c5dd18..d4406d4e15ad 100644
> > --- a/Documentation/devicetree/bindings/pci/pci.txt
> > +++ b/Documentation/devicetree/bindings/pci/pci.txt
> > @@ -24,3 +24,11 @@ driver implementation may support the following properties:
> >     unsupported link speed, for instance, trying to do training for
> >     unsupported link speed, etc.  Must be '4' for gen4, '3' for gen3, '2'
> >     for gen2, and '1' for gen1. Any other values are invalid.
> > +- interrupts: Interrupt specifier for each name in interrupt-names.
> > +- interrupt-names: May contains "wakeup" for PCIe WAKE# interrupt.
> 
> s/contains/contain/
> 
> > +
> > +PCI devices have standardized Device Tree bindings:
> 
> This line is a little unclear, especially since there *is* an old
> documented standard, yet the following text is actually introducing new,
> non-standard additions.
> 
> > +
> > +- interrupts: Interrupt specifier for each name in interrupt-names.
> > +- interrupt-names: May contains "wakeup" for PCIe WAKE# interrupt and "pci" for
> 
> s/contains/contain/
> 
> > +  PCI interrupt.
> 
> IMO, since you're trying to augment a standardized binding, you need to
> be a lot clearer here. I expect you should mention the existing standard
> (that devices may optionally include an 'interrupts' property that
> represents the legacy PCI interrupt) and how you're augmenting it (that
> additional interrupts can be supported optionally, but they require a
> corresponding 'interrupt-names' property).

There's an additional complication that I'd guess the wakeup is 
typically a GPIO line and hence a different parent. We have 2 options 
there. The first is interrupts-extended which is generally implicitly 
supported (i.e. we only document interrupts). The second is we already 
have interrupt-map if we have legacy interrupts and can map to different 
parents. For this to work, we'd have to use a number >4 for the wakeup 
interrupts.

Rob
Tony Lindgren Nov. 2, 2017, 9:55 p.m. UTC | #3
* Rob Herring <robh@kernel.org> [171101 21:07]:
> On Fri, Oct 27, 2017 at 01:45:17PM -0700, Brian Norris wrote:
> > IMO, since you're trying to augment a standardized binding, you need to
> > be a lot clearer here. I expect you should mention the existing standard
> > (that devices may optionally include an 'interrupts' property that
> > represents the legacy PCI interrupt) and how you're augmenting it (that
> > additional interrupts can be supported optionally, but they require a
> > corresponding 'interrupt-names' property).
> 
> There's an additional complication that I'd guess the wakeup is 
> typically a GPIO line and hence a different parent. We have 2 options 
> there. The first is interrupts-extended which is generally implicitly 
> supported (i.e. we only document interrupts). The second is we already 
> have interrupt-map if we have legacy interrupts and can map to different 
> parents. For this to work, we'd have to use a number >4 for the wakeup 
> interrupts.

The wakeup interrupt can also be a separate always on interrupt
controller in addition to GPIOs. Anyways, the interrupts-extended
binding works well for these. And the interrupt-names we seem
to have standardized on are "irq" and "wakeup".

Regards,

Tony
diff mbox

Patch

diff --git a/Documentation/devicetree/bindings/pci/pci.txt b/Documentation/devicetree/bindings/pci/pci.txt
index c77981c5dd18..d4406d4e15ad 100644
--- a/Documentation/devicetree/bindings/pci/pci.txt
+++ b/Documentation/devicetree/bindings/pci/pci.txt
@@ -24,3 +24,11 @@  driver implementation may support the following properties:
    unsupported link speed, for instance, trying to do training for
    unsupported link speed, etc.  Must be '4' for gen4, '3' for gen3, '2'
    for gen2, and '1' for gen1. Any other values are invalid.
+- interrupts: Interrupt specifier for each name in interrupt-names.
+- interrupt-names: May contains "wakeup" for PCIe WAKE# interrupt.
+
+PCI devices have standardized Device Tree bindings:
+
+- interrupts: Interrupt specifier for each name in interrupt-names.
+- interrupt-names: May contains "wakeup" for PCIe WAKE# interrupt and "pci" for
+  PCI interrupt.