[PATCH v4 05/14] usb: hub: Associate port@ fwnode with USB port device

[Chen-Yu Tsai]

When a USB hub port is connected to a connector in a firmware node
graph, the port itself has a node in the graph.

Associate the port's firmware node with the USB port's device,
usb_port::dev. This is used in later changes for the M.2 slot power
sequencing provider to match against the requesting port.

To avoid potential conflicts with ACPI firmware nodes and then causing
power management issues, only assign the firmware node if the hub's
firmware node is not an ACPI firmware node.

Reviewed-by: Andy Shevchenko <andriy.shevchenko at linux.intel.com>
Reviewed-by: Bartosz Golaszewski <bartosz.golaszewski at oss.qualcomm.com>
Signed-off-by: Chen-Yu Tsai <wenst at chromium.org>
---
Changes since v3:
- Added missing fwnode_handle_put()

Changes since v2:
- Skip assignment if hub firmware node is ACPI node
---
 drivers/usb/core/port.c | 14 ++++++++++++++
 1 file changed, 14 insertions(+)

diff --git a/drivers/usb/core/port.c b/drivers/usb/core/port.c
index b1364f0c384c..e8fb2acd77be 100644
--- a/drivers/usb/core/port.c
+++ b/drivers/usb/core/port.c
@@ -7,6 +7,7 @@
  * Author: Lan Tianyu <tianyu.lan at intel.com>
  */
 
+#include <linux/acpi.h>
 #include <linux/kstrtox.h>
 #include <linux/slab.h>
 #include <linux/string_choices.h>
@@ -358,6 +359,11 @@ static void usb_port_device_release(struct device *dev)
 {
 	struct usb_port *port_dev = to_usb_port(dev);
 
+	/*
+	 * At this point ACPI nodes and swnodes have been removed by
+	 * device_platform_notify_remove() in device_del().
+	 */
+	fwnode_handle_put(dev_fwnode(dev));
 	kfree(port_dev->req);
 	kfree(port_dev);
 }
@@ -780,6 +786,13 @@ int usb_hub_create_port_device(struct usb_hub *hub, int port1)
 	port_dev->dev.driver = &usb_port_driver;
 	dev_set_name(&port_dev->dev, "%s-port%d", dev_name(&hub->hdev->dev),
 			port1);
+	/*
+	 * ACPI FW nodes are associated later when device_register() happens.
+	 * Skip assigning one here to avoid potential conflicts.
+	 */
+	if (!is_acpi_node(dev_fwnode(&hdev->dev)))
+		device_set_node(&port_dev->dev,
+				fwnode_graph_get_port_by_id(dev_fwnode(&hdev->dev), port1));
 	mutex_init(&port_dev->status_lock);
 	retval = device_register(&port_dev->dev);
 	if (retval) {
@@ -852,6 +865,7 @@ int usb_hub_create_port_device(struct usb_hub *hub, int port1)
 
 void usb_hub_remove_port_device(struct usb_hub *hub, int port1)
 {
+	struct usb_device *hdev = hub->hdev;
 	struct usb_port *port_dev = hub->ports[port1 - 1];
 	struct usb_port *peer;
 
-- 
2.55.0.795.g602f6c329a-goog