Commit dc12273f authored by Herve Codina's avatar Herve Codina Committed by Rob Herring (Arm)
Browse files

PCI: of_property: Add interrupt-controller property in PCI device nodes 

PCI devices and bridges DT nodes created during the PCI scan are created
with the interrupt-map property set to handle interrupts.

In order to set this interrupt-map property at a specific level, a
phandle to the parent interrupt controller is needed. On systems that
are not fully described by a device-tree, the parent interrupt
controller may be unavailable (i.e. not described by the device-tree).

As mentioned in the [1], avoiding the use of the interrupt-map property
and considering a PCI device as an interrupt controller itself avoid the
use of a parent interrupt phandle.

In that case, the PCI device itself as an interrupt controller is
responsible for routing the interrupts described in the device-tree
world (DT overlay) to the PCI interrupts.

Add the 'interrupt-controller' property in the PCI device DT node.

[1]: https://lore.kernel.org/lkml/CAL_Jsq+je7+9ATR=B6jXHjEJHjn24vQFs4Tvi9=vhDeK9n42Aw@mail.gmail.com/



Signed-off-by: default avatarHerve Codina <herve.codina@bootlin.com>
Acked-by: default avatarBjorn Helgaas <bhelgaas@google.com>
Link: https://lore.kernel.org/r/20240527161450.326615-18-herve.codina@bootlin.com


Signed-off-by: default avatarRob Herring (Arm) <robh@kernel.org>
parent 1e436839

drivers/pci/of_property.c

+24 −0
Original line number Diff line number Diff line
@@ -183,6 +183,26 @@ static int of_pci_prop_interrupts(struct pci_dev *pdev, 
	return of_changeset_add_prop_u32(ocs, np, "interrupts", (u32)pin);

}



static int of_pci_prop_intr_ctrl(struct pci_dev *pdev, struct of_changeset *ocs,

				 struct device_node *np)

{

	int ret;

	u8 pin;



	ret = pci_read_config_byte(pdev, PCI_INTERRUPT_PIN, &pin);

	if (ret != 0)

		return ret;



	if (!pin)

		return 0;



	ret = of_changeset_add_prop_u32(ocs, np, "#interrupt-cells", 1);

	if (ret)

		return ret;



	return of_changeset_add_prop_bool(ocs, np, "interrupt-controller");

}



static int of_pci_prop_intr_map(struct pci_dev *pdev, struct of_changeset *ocs,

				struct device_node *np)

{
@@ -336,6 +356,10 @@ int of_pci_add_properties(struct pci_dev *pdev, struct of_changeset *ocs, 
		ret = of_pci_prop_intr_map(pdev, ocs, np);

		if (ret)

			return ret;

	} else {

		ret = of_pci_prop_intr_ctrl(pdev, ocs, np);

		if (ret)

			return ret;

	}



	ret = of_pci_prop_ranges(pdev, ocs, np);