These functions allows to deactivate gadget to make it not visible to
host and make it active again when gadget driver is finally ready.
They are needed to fix usb_function_activate() and usb_function_deactivate()
functions which currently are not working as usb_gadget_connect() is
called immediately after function bind regardless to previous calls of
usb_gadget_disconnect() function.
Signed-off-by: Robert Baldyga <r.baldyga@xxxxxxxxxxx>
---
include/linux/usb/gadget.h | 100 ++++++++++++++++++++++++++++++++++++++++++---
1 file changed, 94 insertions(+), 6 deletions(-)
diff --git a/include/linux/usb/gadget.h b/include/linux/usb/gadget.h
index 4f3dfb7..15604bb 100644
--- a/include/linux/usb/gadget.h
+++ b/include/linux/usb/gadget.h
@@ -526,6 +526,9 @@ struct usb_gadget_ops {
* @quirk_ep_out_aligned_size: epout requires buffer size to be aligned to
* MaxPacketSize.
* @is_selfpowered: if the gadget is self-powered.
+ * @deactivated: True if gadget is deactivated - in deactivated state it cannot
+ * be connected.
+ * @connected: True if gadget is connected.
*
* Gadgets have a mostly-portable "gadget driver" implementing device
* functions, handling all usb configurations and interfaces. Gadget
@@ -568,6 +571,8 @@ struct usb_gadget {
unsigned a_alt_hnp_support:1;
unsigned quirk_ep_out_aligned_size:1;
unsigned is_selfpowered:1;
+ unsigned deactivated:1;
+ unsigned connected:1;
};
#define work_to_gadget(w) (container_of((w), struct usb_gadget, work))
@@ -771,9 +776,24 @@ static inline int usb_gadget_vbus_disconnect(struct usb_gadget *gadget)
*/
static inline int usb_gadget_connect(struct usb_gadget *gadget)
{
+ int ret;
+
if (!gadget->ops->pullup)
return -EOPNOTSUPP;
- return gadget->ops->pullup(gadget, 1);
+
+ if (gadget->deactivated) {
+ /*
+ * If gadget is deactivated we only save new state.
+ * Gadget will be connected automatically after activation.
+ */
+ gadget->connected = true;
+ return 0;
+ }
+
+ ret = gadget->ops->pullup(gadget, 1);
+ if (!ret)
+ gadget->connected = 1;
+ return ret;
}
/**
@@ -784,20 +804,88 @@ static inline int usb_gadget_connect(struct usb_gadget *gadget)
* as a disconnect (when a VBUS session is active). Not all systems
* support software pullup controls.
*
+ * Returns zero on success, else negative errno.
+ */
+static inline int usb_gadget_disconnect(struct usb_gadget *gadget)
+{
+ int ret;
+
+ if (!gadget->ops->pullup)
+ return -EOPNOTSUPP;
+
+ if (gadget->deactivated) {
+ /*
+ * If gadget is deactivated we only save new state.
+ * Gadget will stay disconnected after activation.
+ */
+ gadget->connected = false;
+ return 0;
+ }
+
+ ret = gadget->ops->pullup(gadget, 0);
+ if (!ret)
+ gadget->connected = 0;
+ return ret;
+}
+
+/**
+ * usb_gadget_deactivate - deactivate function which is not ready to work
+ * @gadget: the peripheral being deactivated
+ *
* This routine may be used during the gadget driver bind() call to prevent
* the peripheral from ever being visible to the USB host, unless later
- * usb_gadget_connect() is called. For example, user mode components may
+ * usb_gadget_activate() is called. For example, user mode components may
* need to be activated before the system can talk to hosts.
*
* Returns zero on success, else negative errno.
*/
-static inline int usb_gadget_disconnect(struct usb_gadget *gadget)
+static inline int usb_gadget_deactivate(struct usb_gadget *gadget)
{
- if (!gadget->ops->pullup)
- return -EOPNOTSUPP;
- return gadget->ops->pullup(gadget, 0);
+ int ret;
+
+ if (gadget->deactivated)
+ return 0;
+
+ if (gadget->connected) {
+ ret = usb_gadget_disconnect(gadget);
+ if (ret)
+ return ret;
+ /*
+ * If gadget was being connected before deactivation, we want
+ * to reconnect it in usb_gadget_activate().
+ */
+ gadget->connected = true;
+ }
+ gadget->deactivated = true;
+
+ return 0;
}
+/**
+ * usb_gadget_activate - activate function which is not ready to work
+ * @gadget: the peripheral being activated
+ *
+ * This routine activates gadget which was previously deactivated with
+ * usb_gadget_deactivate() call. It calls usb_gadget_connect() if needed.
+ *
+ * Returns zero on success, else negative errno.
+ */
+static inline int usb_gadget_activate(struct usb_gadget *gadget)
+{
+ if (!gadget->deactivated)
+ return 0;
+
+ gadget->deactivated = false;
+
+ /*
+ * If gadget has been connected before deactivation, or became connected
+ * while it was being deactivated, we call usb_gadget_connect().
+ */
+ if (gadget->connected)
+ return usb_gadget_connect(gadget);
+
+ return 0;
+}
/*-------------------------------------------------------------------------*/
--
1.9.1
--
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