[PATCH v3 1/5] usb: typec: Add mode_control field to port property

Andrei Kuchynski
2025-09-05T14:22:16Z

This new field in the port properties dictates whether the Platform Policy
Manager (PPM) allows the OS Policy Manager (OPM) to change the currently
active, negotiated alternate mode.

Signed-off-by: Andrei Kuchynski <akuchynski@chromium.org>
---
drivers/usb/typec/class.c | 9 ++++++---
drivers/usb/typec/class.h | 2 ++
include/linux/usb/typec.h | 2 ++
3 files changed, 10 insertions(+), 3 deletions(-)

diff --git a/drivers/usb/typec/class.c b/drivers/usb/typec/class.c
index 67a533e35150..9f86605ce125 100644
--- a/drivers/usb/typec/class.c
+++ b/drivers/usb/typec/class.c
@@ -457,11 +457,13 @@ static umode_t typec_altmode_attr_is_visible(struct kobject *kobj,
struct attribute *attr, int n)
{
struct typec_altmode *adev = to_typec_altmode(kobj_to_dev(kobj));
+ struct typec_port *port = typec_altmode2port(adev);

if (attr == &dev_attr_active.attr)
- if (!is_typec_port(adev->dev.parent) &&
- (!adev->ops || !adev->ops->activate))
- return 0444;
+ if (!is_typec_port(adev->dev.parent)) {
+ if (!port->mode_control || !adev->ops || !adev->ops->activate)
+ return 0444;
+ }

return attr->mode;
}
@@ -2681,6 +2683,7 @@ struct typec_port *typec_register_port(struct device *parent,
}

port->pd = cap->pd;
+ port->mode_control = !cap->no_mode_control;

ret = device_add(&port->dev);
if (ret) {
diff --git a/drivers/usb/typec/class.h b/drivers/usb/typec/class.h
index db2fe96c48ff..c53a04b9dc75 100644
--- a/drivers/usb/typec/class.h
+++ b/drivers/usb/typec/class.h
@@ -80,6 +80,8 @@ struct typec_port {
*/
struct device *usb2_dev;
struct device *usb3_dev;
+
+ bool mode_control;
};

#define to_typec_port(_dev_) container_of(_dev_, struct typec_port, dev)
diff --git a/include/linux/usb/typec.h b/include/linux/usb/typec.h
index 252af3f77039..8f51665d44ec 100644
--- a/include/linux/usb/typec.h
+++ b/include/linux/usb/typec.h
@@ -287,6 +287,7 @@ enum usb_pd_svdm_ver {
* @prefer_role: Initial role preference (DRP ports).
* @accessory: Supported Accessory Modes
* @usb_capability: Supported USB Modes
+ * @no_mode_control: Ability to manage Alternate Modes
* @fwnode: Optional fwnode of the port
* @driver_data: Private pointer for driver specific info
* @pd: Optional USB Power Delivery Support
@@ -304,6 +305,7 @@ struct typec_capability {
enum typec_accessory accessory[TYPEC_MAX_ACCESSORY];
unsigned int orientation_aware:1;
u8 usb_capability;
+ bool no_mode_control;

struct fwnode_handle *fwnode;
void *driver_data;
--
2.51.0.355.g5224444f11-goog