| Message ID | 20171027072612.26565-2-jeffy.chen@rock-chips.com (mailing list archive) |
|---|---|
| State | RFC, archived |
| Headers | show |
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
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
* 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 --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.
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(+)