Allow device specific drivers to change the wireless status of a device.
This will allow user-space to know whether the device is available,
whether or not specific USB interfaces can detect it.
This can be used by wireless headsets with USB receivers to propagate to
user-space whether or not the headset is turned on, so as to consider it
as unavailable, and not switch to it just because the receiver is
plugged in.
Signed-off-by: Bastien Nocera <hadess@xxxxxxxxxx>
---
drivers/usb/core/message.c | 13 +++++++++++++
drivers/usb/core/usb.c | 24 ++++++++++++++++++++++++
include/linux/usb.h | 4 ++++
3 files changed, 41 insertions(+)
diff --git a/drivers/usb/core/message.c b/drivers/usb/core/message.c
index 127fac1af676..d5c7749d515e 100644
--- a/drivers/usb/core/message.c
+++ b/drivers/usb/core/message.c
@@ -1908,6 +1908,18 @@ static void __usb_queue_reset_device(struct work_struct *ws)
usb_put_intf(iface); /* Undo _get_ in usb_queue_reset_device() */
}
+/*
+ * Internal function to set the wireless_status sysfs attribute
+ * See usb_set_wireless_status() for more details
+ */
+static void __usb_wireless_status_intf(struct work_struct *ws)
+{
+ struct usb_interface *iface =
+ container_of(ws, struct usb_interface, wireless_status_work);
+
+ usb_update_wireless_status_attr(iface);
+ usb_put_intf(iface); /* Undo _get_ in usb_set_wireless_status() */
+}
/*
* usb_set_configuration - Makes a particular device setting be current
@@ -2100,6 +2112,7 @@ int usb_set_configuration(struct usb_device *dev, int configuration)
intf->dev.type = &usb_if_device_type;
intf->dev.groups = usb_interface_groups;
INIT_WORK(&intf->reset_ws, __usb_queue_reset_device);
+ INIT_WORK(&intf->wireless_status_work, __usb_wireless_status_intf);
intf->minor = -1;
device_initialize(&intf->dev);
pm_runtime_no_callbacks(&intf->dev);
diff --git a/drivers/usb/core/usb.c b/drivers/usb/core/usb.c
index 11b15d7b357a..5f42c5b9d209 100644
--- a/drivers/usb/core/usb.c
+++ b/drivers/usb/core/usb.c
@@ -871,6 +871,30 @@ int usb_get_current_frame_number(struct usb_device *dev)
}
EXPORT_SYMBOL_GPL(usb_get_current_frame_number);
+/**
+ * usb_set_wireless_status - sets the wireless_status struct member
+ * @dev: the device to modify
+ * @status: the new wireless status
+ *
+ * Set the wireless_status struct member to the new value, and emit
+ * sysfs changes as necessary.
+ *
+ * Returns: 0 on success, -EALREADY if already set.
+ */
+int usb_set_wireless_status(struct usb_interface *iface,
+ enum usb_wireless_status status)
+{
+ if (iface->wireless_status == status)
+ return -EALREADY;
+
+ usb_get_intf(iface);
+ iface->wireless_status = status;
+ schedule_work(&iface->wireless_status_work);
+
+ return 0;
+}
+EXPORT_SYMBOL_GPL(usb_set_wireless_status);
+
/*-------------------------------------------------------------------*/
/*
* __usb_get_extra_descriptor() finds a descriptor of specific type in the
diff --git a/include/linux/usb.h b/include/linux/usb.h
index 517ae4b4e333..a48eeec62a66 100644
--- a/include/linux/usb.h
+++ b/include/linux/usb.h
@@ -262,6 +262,7 @@ struct usb_interface {
unsigned resetting_device:1; /* true: bandwidth alloc after reset */
unsigned authorized:1; /* used for interface authorization */
enum usb_wireless_status wireless_status;
+ struct work_struct wireless_status_work;
struct device dev; /* interface specific device info */
struct device *usb_dev;
@@ -897,6 +898,9 @@ static inline int usb_interface_claimed(struct usb_interface *iface)
extern void usb_driver_release_interface(struct usb_driver *driver,
struct usb_interface *iface);
+int usb_set_wireless_status(struct usb_interface *iface,
+ enum usb_wireless_status status);
+
const struct usb_device_id *usb_match_id(struct usb_interface *interface,
const struct usb_device_id *id);
extern int usb_match_one_id(struct usb_interface *interface,
--
2.39.2
