aboutsummaryrefslogtreecommitdiff
path: root/drivers/usb/gadget/composite.c
diff options
context:
space:
mode:
Diffstat (limited to 'drivers/usb/gadget/composite.c')
-rw-r--r--drivers/usb/gadget/composite.c68
1 files changed, 66 insertions, 2 deletions
diff --git a/drivers/usb/gadget/composite.c b/drivers/usb/gadget/composite.c
index 85c876c1f15..f2da0269e1b 100644
--- a/drivers/usb/gadget/composite.c
+++ b/drivers/usb/gadget/composite.c
@@ -128,6 +128,70 @@ done:
}
/**
+ * usb_function_deactivate - prevent function and gadget enumeration
+ * @function: the function that isn't yet ready to respond
+ *
+ * Blocks response of the gadget driver to host enumeration by
+ * preventing the data line pullup from being activated. This is
+ * normally called during @bind() processing to change from the
+ * initial "ready to respond" state, or when a required resource
+ * becomes available.
+ *
+ * For example, drivers that serve as a passthrough to a userspace
+ * daemon can block enumeration unless that daemon (such as an OBEX,
+ * MTP, or print server) is ready to handle host requests.
+ *
+ * Not all systems support software control of their USB peripheral
+ * data pullups.
+ *
+ * Returns zero on success, else negative errno.
+ */
+int usb_function_deactivate(struct usb_function *function)
+{
+ struct usb_composite_dev *cdev = function->config->cdev;
+ int status = 0;
+
+ spin_lock(&cdev->lock);
+
+ if (cdev->deactivations == 0)
+ status = usb_gadget_disconnect(cdev->gadget);
+ if (status == 0)
+ cdev->deactivations++;
+
+ spin_unlock(&cdev->lock);
+ return status;
+}
+
+/**
+ * usb_function_activate - allow function and gadget enumeration
+ * @function: function on which usb_function_activate() was called
+ *
+ * Reverses effect of usb_function_deactivate(). If no more functions
+ * are delaying their activation, the gadget driver will respond to
+ * host enumeration procedures.
+ *
+ * Returns zero on success, else negative errno.
+ */
+int usb_function_activate(struct usb_function *function)
+{
+ struct usb_composite_dev *cdev = function->config->cdev;
+ int status = 0;
+
+ spin_lock(&cdev->lock);
+
+ if (WARN_ON(cdev->deactivations == 0))
+ status = -EINVAL;
+ else {
+ cdev->deactivations--;
+ if (cdev->deactivations == 0)
+ status = usb_gadget_connect(cdev->gadget);
+ }
+
+ spin_unlock(&cdev->lock);
+ return status;
+}
+
+/**
* usb_interface_id() - allocate an unused interface ID
* @config: configuration associated with the interface
* @function: function handling the interface
@@ -181,7 +245,7 @@ static int config_buf(struct usb_configuration *config,
c->bConfigurationValue = config->bConfigurationValue;
c->iConfiguration = config->iConfiguration;
c->bmAttributes = USB_CONFIG_ATT_ONE | config->bmAttributes;
- c->bMaxPower = config->bMaxPower;
+ c->bMaxPower = config->bMaxPower ? : (CONFIG_USB_GADGET_VBUS_DRAW / 2);
/* There may be e.g. OTG descriptors */
if (config->descriptors) {
@@ -368,7 +432,7 @@ static int set_config(struct usb_composite_dev *cdev,
}
/* when we return, be sure our power usage is valid */
- power = 2 * c->bMaxPower;
+ power = c->bMaxPower ? (2 * c->bMaxPower) : CONFIG_USB_GADGET_VBUS_DRAW;
done:
usb_gadget_vbus_draw(gadget, power);
return result;