2022-04-19 12:08:12

by Won Chung

[permalink] [raw]
Subject: [PATCH 2/2] thunderbolt: Link USB4 ports to their USB Type-C connectors

From: Heikki Krogerus <[email protected]>

Creating a symlink pointing to the correct USB Type-C
connector for the on-board USB4 ports when they are created.
The link will be created only if the firmware is able to
describe the connection between the port and its connector.

Signed-off-by: Heikki Krogerus <[email protected]>
Signed-off-by: Won Chung <[email protected]>
---
.../ABI/testing/sysfs-bus-thunderbolt | 10 +++++
drivers/thunderbolt/usb4_port.c | 38 +++++++++++++++++++
2 files changed, 48 insertions(+)

diff --git a/Documentation/ABI/testing/sysfs-bus-thunderbolt b/Documentation/ABI/testing/sysfs-bus-thunderbolt
index b7e87f6c7d47..f7570c240ce8 100644
--- a/Documentation/ABI/testing/sysfs-bus-thunderbolt
+++ b/Documentation/ABI/testing/sysfs-bus-thunderbolt
@@ -293,6 +293,16 @@ Contact: [email protected]
Description: This contains XDomain service specific settings as
bitmask. Format: %x

+What: /sys/bus/thunderbolt/devices/usb4_portX/connector
+Date: April 2022
+Contact: Heikki Krogerus <[email protected]>
+Description:
+ Symlink to the USB Type-C connector. This link is only
+ created when USB Type-C Connector Class is enabled,
+ and only if the system firmware is capable of
+ describing the connection between a port and its
+ connector.
+
What: /sys/bus/thunderbolt/devices/usb4_portX/link
Date: Sep 2021
KernelVersion: v5.14
diff --git a/drivers/thunderbolt/usb4_port.c b/drivers/thunderbolt/usb4_port.c
index 29e2a4f9c9f5..6b02945624ee 100644
--- a/drivers/thunderbolt/usb4_port.c
+++ b/drivers/thunderbolt/usb4_port.c
@@ -7,9 +7,37 @@
*/

#include <linux/pm_runtime.h>
+#include <linux/component.h>
+#include <linux/property.h>

#include "tb.h"

+static int connector_bind(struct device *dev, struct device *connector, void *data)
+{
+ int ret;
+
+ ret = sysfs_create_link(&dev->kobj, &connector->kobj, "connector");
+ if (ret)
+ return ret;
+
+ ret = sysfs_create_link(&connector->kobj, &dev->kobj, dev_name(dev));
+ if (ret)
+ sysfs_remove_link(&dev->kobj, "connector");
+
+ return ret;
+}
+
+static void connector_unbind(struct device *dev, struct device *connector, void *data)
+{
+ sysfs_remove_link(&connector->kobj, dev_name(dev));
+ sysfs_remove_link(&dev->kobj, "connector");
+}
+
+static const struct component_ops connector_ops = {
+ .bind = connector_bind,
+ .unbind = connector_unbind,
+};
+
static ssize_t link_show(struct device *dev, struct device_attribute *attr,
char *buf)
{
@@ -246,6 +274,14 @@ struct usb4_port *usb4_port_device_add(struct tb_port *port)
return ERR_PTR(ret);
}

+ if (dev_fwnode(&usb4->dev)) {
+ ret = component_add(&usb4->dev, &connector_ops);
+ if (ret) {
+ dev_err(&usb4->dev, "failed to add component\n");
+ device_unregister(&usb4->dev);
+ }
+ }
+
pm_runtime_no_callbacks(&usb4->dev);
pm_runtime_set_active(&usb4->dev);
pm_runtime_enable(&usb4->dev);
@@ -265,6 +301,8 @@ struct usb4_port *usb4_port_device_add(struct tb_port *port)
*/
void usb4_port_device_remove(struct usb4_port *usb4)
{
+ if (dev_fwnode(&usb4->dev))
+ component_del(&usb4->dev, &connector_ops);
device_unregister(&usb4->dev);
}

--
2.36.0.rc0.470.gd361397f0d-goog