[PATCH v2 2/2] PCI: of: Attach created of_node to existing device

Herve Codina
2023-11-30T16:57:25Z

The commit 407d1a51921e ("PCI: Create device tree node for bridge")
creates of_node for PCI devices.
During the insertion handling of these new DT nodes done by of_platform,
new devices (struct device) are created.
For each PCI devices a struct device is already present (created and
handled by the PCI core).
Having a second struct device to represent the exact same PCI device is
not correct.

On the of_node creation, tell the of_platform that there is no need to
create a device for this node (OF_POPULATED flag), link this newly
created of_node to the already present device and tell fwnode that the
device attached to this of_node is ready (fwnode_dev_initialized()).

With this fix, the of_node are available in the sysfs device tree:
/sys/devices/platform/soc/d0070000.pcie/
+ of_node -> .../devicetree/base/soc/pcie@d0070000
+ pci0000:00
+ 0000:00:00.0
+ of_node -> .../devicetree/base/soc/pcie@d0070000/pci@0,0
+ 0000:01:00.0
+ of_node -> .../devicetree/base/soc/pcie@d0070000/pci@0,0/dev@0,0

On the of_node removal, revert the operations.

Fixes: 407d1a51921e ("PCI: Create device tree node for bridge")
Cc: stable@vger.kernel.org
Signed-off-by: Herve Codina <herve.codina@bootlin.com>
---
drivers/pci/of.c | 15 +++++++++++++--
1 file changed, 13 insertions(+), 2 deletions(-)

diff --git a/drivers/pci/of.c b/drivers/pci/of.c
index 51e3dd0ea5ab..5afd2731e876 100644
--- a/drivers/pci/of.c
+++ b/drivers/pci/of.c
@@ -615,7 +615,8 @@ void of_pci_remove_node(struct pci_dev *pdev)
np = pci_device_to_OF_node(pdev);
if (!np || !of_node_check_flag(np, OF_DYNAMIC))
return;
- pdev->dev.of_node = NULL;
+
+ device_remove_of_node(&pdev->dev);

of_changeset_revert(np->data);
of_changeset_destroy(np->data);
@@ -668,12 +669,22 @@ void of_pci_make_dev_node(struct pci_dev *pdev)
if (ret)
goto out_free_node;

+ /*
+ * This of_node will be added to an existing device.
+ * Avoid any device creation and use the existing device
+ */
+ of_node_set_flag(np, OF_POPULATED);
+ np->fwnode.dev = &pdev->dev;
+ fwnode_dev_initialized(&np->fwnode, true);
+
ret = of_changeset_apply(cset);
if (ret)
goto out_free_node;

np->data = cset;
- pdev->dev.of_node = np;
+
+ /* Add the of_node to the existing device */
+ device_add_of_node(&pdev->dev, np);
kfree(name);

return;
--
2.42.0