A function which is in function suspend state has to send a
function wake notification to the host in case it needs to
exit from this state and resume data transfer. Add support to
handle such requests by exposing a new gadget op.
Signed-off-by: Elson Roy Serrao <quic_eserrao@xxxxxxxxxxx>
---
drivers/usb/gadget/composite.c | 40 ++++++++++++++++++++++++++++++++++++++++
include/linux/usb/composite.h | 6 ++++++
include/linux/usb/gadget.h | 1 +
3 files changed, 47 insertions(+)
diff --git a/drivers/usb/gadget/composite.c b/drivers/usb/gadget/composite.c
index 7512854..7ae78c05 100644
--- a/drivers/usb/gadget/composite.c
+++ b/drivers/usb/gadget/composite.c
@@ -492,6 +492,46 @@ int usb_interface_id(struct usb_configuration *config,
}
EXPORT_SYMBOL_GPL(usb_interface_id);
+/**
+ * usb_func_wakeup - sends function wake notification to the host.
+ * @func: function that sends the remote wakeup notification.
+ *
+ * Applicable only to enhanced super speed devices when usb functions
+ * are put in function suspend state and armed for function remote wakeup.
+ * On completion, function wake notification is sent. If the device is in
+ * low power state it tries to bring the device to active state before
+ * sending the wake notification. Since it is a synchronous call, caller
+ * must take care of not calling it in interrupt context. For non enhanced
+ * super speed devices operating in lower speeds returns negative errno.
+ *
+ * Returns zero on success, else negative errno.
+ */
+int usb_func_wakeup(struct usb_function *func)
+{
+ struct usb_gadget *gadget = func->config->cdev->gadget;
+ int id;
+
+ if (!func->func_wakeup_armed) {
+ ERROR(func->config->cdev, "not armed for func remote wakeup\n");
+ return -EINVAL;
+ }
+
+ if (!gadget->ops->func_wakeup)
+ return -EOPNOTSUPP;
+
+ for (id = 0; id < MAX_CONFIG_INTERFACES; id++)
+ if (func->config->interface[id] == func)
+ break;
+
+ if (id == MAX_CONFIG_INTERFACES) {
+ ERROR(func->config->cdev, "Invalid function\n");
+ return -EINVAL;
+ }
+
+ return gadget->ops->func_wakeup(gadget, id);
+}
+EXPORT_SYMBOL_GPL(usb_func_wakeup);
+
static u8 encode_bMaxPower(enum usb_device_speed speed,
struct usb_configuration *c)
{
diff --git a/include/linux/usb/composite.h b/include/linux/usb/composite.h
index d949e91..a2448e9 100644
--- a/include/linux/usb/composite.h
+++ b/include/linux/usb/composite.h
@@ -150,6 +150,9 @@ struct usb_os_desc_table {
* GetStatus() request when the recipient is Interface.
* @func_suspend: callback to be called when
* SetFeature(FUNCTION_SUSPEND) is reseived
+ * @func_suspended: Indicates whether the function is in function suspend state.
+ * @func_wakeup_armed: Indicates whether the function is armed by the host for
+ * wakeup signaling.
*
* A single USB function uses one or more interfaces, and should in most
* cases support operation at both full and high speeds. Each function is
@@ -220,6 +223,8 @@ struct usb_function {
int (*get_status)(struct usb_function *);
int (*func_suspend)(struct usb_function *,
u8 suspend_opt);
+ bool func_suspended;
+ bool func_wakeup_armed;
/* private: */
/* internals */
struct list_head list;
@@ -241,6 +246,7 @@ int config_ep_by_speed_and_alt(struct usb_gadget *g, struct usb_function *f,
int config_ep_by_speed(struct usb_gadget *g, struct usb_function *f,
struct usb_ep *_ep);
+int usb_func_wakeup(struct usb_function *func);
#define MAX_CONFIG_INTERFACES 16 /* arbitrary; max 255 */
diff --git a/include/linux/usb/gadget.h b/include/linux/usb/gadget.h
index 1d79612..75bda078 100644
--- a/include/linux/usb/gadget.h
+++ b/include/linux/usb/gadget.h
@@ -310,6 +310,7 @@ struct usb_udc;
struct usb_gadget_ops {
int (*get_frame)(struct usb_gadget *);
int (*wakeup)(struct usb_gadget *);
+ int (*func_wakeup)(struct usb_gadget *gadget, int intf_id);
int (*set_remote_wakeup)(struct usb_gadget *, int set);
int (*set_selfpowered) (struct usb_gadget *, int is_selfpowered);
int (*vbus_session) (struct usb_gadget *, int is_active);
--
2.7.4
