PCI/pwrctl: Reuse the OF node for power controlled devices

With PCI power control we deal with two struct device objects bound to
two different drivers but consuming the same OF node. We must not bind
the pinctrl twice. To that end: before setting the OF node of the newly
instantiated PCI device, check if a platform device consuming the same
OF node doesn't already exist on the platform bus and - if so - mark the
PCI device as reusing the OF node.

Tested-by: Amit Pundir <amit.pundir@linaro.org>
Tested-by: Neil Armstrong <neil.armstrong@linaro.org> # on SM8550-QRD, SM8650-QRD & SM8650-HDK
Tested-by: Caleb Connolly <caleb.connolly@linaro.org> # OnePlus 8T
Acked-by: Bjorn Helgaas <bhelgaas@google.com>
Link: https://lore.kernel.org/r/20240612082019.19161-3-brgl@bgdev.pl
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>

diff --git a/drivers/pci/of.c b/drivers/pci/of.c
index 51e3dd0ea5abe02c4e9ce07d096f5ded30f26883..b908fe1ae951e9a226f57c3cdeda04f1d6acae31 100644 (file)
--- a/drivers/pci/of.c
+++ b/drivers/pci/of.c
@@ -6,6 +6,7 @@
  */
 #define pr_fmt(fmt)    "PCI: OF: " fmt
 
+#include <linux/cleanup.h>
 #include <linux/irqdomain.h>
 #include <linux/kernel.h>
 #include <linux/pci.h>
@@ -13,6 +14,7 @@
 #include <linux/of_irq.h>
 #include <linux/of_address.h>
 #include <linux/of_pci.h>
+#include <linux/platform_device.h>
 #include "pci.h"
 
 #ifdef CONFIG_PCI
@@ -25,16 +27,20 @@
  */
 int pci_set_of_node(struct pci_dev *dev)
 {
-       struct device_node *node;
-
        if (!dev->bus->dev.of_node)
                return 0;
 
-       node = of_pci_find_child_device(dev->bus->dev.of_node, dev->devfn);
+       struct device_node *node __free(device_node) =
+               of_pci_find_child_device(dev->bus->dev.of_node, dev->devfn);
        if (!node)
                return 0;
 
-       device_set_node(&dev->dev, of_fwnode_handle(node));
+       struct device *pdev __free(put_device) =
+               bus_find_device_by_of_node(&platform_bus_type, node);
+       if (pdev)
+               dev->bus->dev.of_node_reused = true;
+
+       device_set_node(&dev->dev, of_fwnode_handle(no_free_ptr(node)));
        return 0;
 }