usbcore: add autosuspend/autoresume infrastructure
This patch (as739) adds the basic infrastructure for USB autosuspend
and autoresume. The main features are:
PM usage counters added to struct usb_device and struct
usb_interface, indicating whether it's okay to autosuspend
them or they are currently in use.
Flag added to usb_device indicating whether the current
suspend/resume operation originated from outside or as an
autosuspend/autoresume.
Flag added to usb_driver indicating whether the driver
supports autosuspend. If not, no device bound to the driver
will be autosuspended.
Mutex added to usb_device for protecting PM operations.
Unlike the device semaphore, the locking rule for the pm_mutex
is that you must acquire the locks going _up_ the device tree.
New routines handling autosuspend/autoresume requests for
interfaces and devices.
Suspend and resume requests are propagated up the device tree
(but not outside the USB subsystem).
work_struct added to usb_device, for carrying out delayed
autosuspend requests.
Autoresume added (and autosuspend prevented) during probe and
disconnect.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
diff --git a/include/linux/usb.h b/include/linux/usb.h
index df5c93e..0da15b0 100644
--- a/include/linux/usb.h
+++ b/include/linux/usb.h
@@ -19,6 +19,7 @@
#include <linux/fs.h> /* for struct file_operations */
#include <linux/completion.h> /* for struct completion */
#include <linux/sched.h> /* for current && schedule_timeout */
+#include <linux/mutex.h> /* for struct mutex */
struct usb_device;
struct usb_driver;
@@ -103,8 +104,12 @@
* @condition: binding state of the interface: not bound, binding
* (in probe()), bound to a driver, or unbinding (in disconnect())
* @is_active: flag set when the interface is bound and not suspended.
+ * @needs_remote_wakeup: flag set when the driver requires remote-wakeup
+ * capability during autosuspend.
* @dev: driver model's view of this device
* @class_dev: driver model's class view of this device.
+ * @pm_usage_cnt: PM usage counter for this interface; autosuspend is not
+ * allowed unless the counter is 0.
*
* USB device drivers attach to interfaces on a physical device. Each
* interface encapsulates a single high level function, such as feeding
@@ -144,9 +149,11 @@
* bound to */
enum usb_interface_condition condition; /* state of binding */
unsigned is_active:1; /* the interface is not suspended */
+ unsigned needs_remote_wakeup:1; /* driver requires remote wakeup */
struct device dev; /* interface specific device info */
struct class_device *class_dev;
+ int pm_usage_cnt; /* usage counter for autosuspend */
};
#define to_usb_interface(d) container_of(d, struct usb_interface, dev)
#define interface_to_usbdev(intf) \
@@ -372,6 +379,15 @@
int maxchild; /* Number of ports if hub */
struct usb_device *children[USB_MAXCHILDREN];
+
+#ifdef CONFIG_PM
+ struct work_struct autosuspend; /* for delayed autosuspends */
+ struct mutex pm_mutex; /* protects PM operations */
+ int pm_usage_cnt; /* usage counter for autosuspend */
+
+ unsigned auto_pm:1; /* autosuspend/resume in progress */
+ unsigned do_remote_wakeup:1; /* remote wakeup should be enabled */
+#endif
};
#define to_usb_device(d) container_of(d, struct usb_device, dev)
@@ -392,6 +408,17 @@
extern struct usb_device *usb_find_device(u16 vendor_id, u16 product_id);
+/* USB autosuspend and autoresume */
+#ifdef CONFIG_USB_SUSPEND
+extern int usb_autopm_get_interface(struct usb_interface *intf);
+extern void usb_autopm_put_interface(struct usb_interface *intf);
+
+#else
+#define usb_autopm_get_interface(intf) 0
+#define usb_autopm_put_interface(intf) do {} while (0)
+#endif
+
+
/*-------------------------------------------------------------------------*/
/* for drivers using iso endpoints */
@@ -593,6 +620,8 @@
* @drvwrap: Driver-model core structure wrapper.
* @no_dynamic_id: if set to 1, the USB core will not allow dynamic ids to be
* added to this driver by preventing the sysfs file from being created.
+ * @supports_autosuspend: if set to 0, the USB core will not allow autosuspend
+ * for interfaces bound to this driver.
*
* USB interface drivers must provide a name, probe() and disconnect()
* methods, and an id_table. Other driver fields are optional.
@@ -631,6 +660,7 @@
struct usb_dynids dynids;
struct usbdrv_wrap drvwrap;
unsigned int no_dynamic_id:1;
+ unsigned int supports_autosuspend:1;
};
#define to_usb_driver(d) container_of(d, struct usb_driver, drvwrap.driver)
@@ -648,6 +678,8 @@
* @suspend: Called when the device is going to be suspended by the system.
* @resume: Called when the device is being resumed by the system.
* @drvwrap: Driver-model core structure wrapper.
+ * @supports_autosuspend: if set to 0, the USB core will not allow autosuspend
+ * for devices bound to this driver.
*
* USB drivers must provide all the fields listed above except drvwrap.
*/
@@ -660,6 +692,7 @@
int (*suspend) (struct usb_device *udev, pm_message_t message);
int (*resume) (struct usb_device *udev);
struct usbdrv_wrap drvwrap;
+ unsigned int supports_autosuspend:1;
};
#define to_usb_device_driver(d) container_of(d, struct usb_device_driver, \
drvwrap.driver)