usb: add device connection/disconnection detection
Provide a function to detect USB device insertion/removal in order to
avoid having to do USB enumeration in a tight loop when trying to detect
peripheral hotplugging.
Signed-off-by: Vincent Palatin <vpalatin@chromium.org>
Reviewed-by: Stefan Reinauer <reinauer@chromium.org>
Tested-by: Stefan Reinauer <reinauer@chromium.org>
Signed-off-by: Simon Glass <sjg@chromium.org>
diff --git a/common/usb.c b/common/usb.c
index 20c614c..6283f39 100644
--- a/common/usb.c
+++ b/common/usb.c
@@ -148,6 +148,32 @@
return 0;
}
+/******************************************************************************
+ * Detect if a USB device has been plugged or unplugged.
+ */
+int usb_detect_change(void)
+{
+ int i, j;
+ int change = 0;
+
+ for (j = 0; j < USB_MAX_DEVICE; j++) {
+ for (i = 0; i < usb_dev[j].maxchild; i++) {
+ struct usb_port_status status;
+
+ if (usb_get_port_status(&usb_dev[j], i + 1,
+ &status) < 0)
+ /* USB request failed */
+ continue;
+
+ if (le16_to_cpu(status.wPortChange) &
+ USB_PORT_STAT_C_CONNECTION)
+ change++;
+ }
+ }
+
+ return change;
+}
+
/*
* disables the asynch behaviour of the control message. This is used for data
* transfers that uses the exclusiv access to the control and bulk messages.