Re: [PATCH v2 17/19] PCI: of_property: Add interrupt-controller property in PCI device nodes
From: Bjorn Helgaas <helgaas@kernel.org>
Date: 2024-06-06 19:26:14
Also in:
linux-devicetree, linux-pci, lkml, netdev
On Mon, May 27, 2024 at 06:14:44PM +0200, Herve Codina wrote:
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/ (local) Signed-off-by: Herve Codina <herve.codina@bootlin.com>
No objection from me, but I'd like an ack/review from Rob.
quoted hunk ↗ jump to hunk
--- drivers/pci/of_property.c | 24 ++++++++++++++++++++++++ 1 file changed, 24 insertions(+)diff --git a/drivers/pci/of_property.c b/drivers/pci/of_property.c index 03539e505372..5a0b98e69795 100644 --- a/drivers/pci/of_property.c +++ b/drivers/pci/of_property.c@@ -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);-- 2.45.0
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