usb: implement a usb_host_detect to scan individual USB hosts

Currently we can only (re)scan all USB hosts. Add a function to
scan individual hosts. This is useful for implementing the detect
callback in the next patch.

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

1 files changed, 25 insertions, 13 deletions

diff --git a/drivers/usb/core/usb.c b/drivers/usb/core/usb.c
index 07175dc3f1..36fc736fd0 100644
--- a/drivers/usb/core/usb.c
+++ b/drivers/usb/core/usb.c
@@ -488,20 +488,18 @@ static struct usb_device *usb_alloc_new_device(void)
 	return usbdev;
 }
 
-static int scanned;
-
-void usb_rescan(int force)
+int usb_host_detect(struct usb_host *host, int force)
 {
 	struct usb_device *dev, *tmp;
-	struct usb_host *host;
 	int ret;
 
-	if (scanned && !force)
-		return;
-
-	scanned = 1;
+	if (host->scanned && !force)
+		return -EBUSY;
 
 	list_for_each_entry_safe(dev, tmp, &usb_device_list, list) {
+		if (dev->host != host)
+			continue;
+
 		list_del(&dev->list);
 		unregister_device(&dev->dev);
 		if (dev->hub)
@@ -511,17 +509,31 @@ void usb_rescan(int force)
 		free(dev);
 	}
 
+	ret = host->init(host);
+	if (ret)
+		return ret;
+
+	dev = usb_alloc_new_device();
+	dev->host = host;
+	usb_new_device(dev);
+
+	host->scanned = 1;
+
+	return 0;
+}
+
+void usb_rescan(int force)
+{
+	struct usb_host *host;
+	int ret;
+
 	printf("USB: scanning bus for devices...\n");
 	dev_index = 0;
 
 	list_for_each_entry(host, &host_list, list) {
-		ret = host->init(host);
+		ret = usb_host_detect(host, force);
 		if (ret)
 			continue;
-
-		dev = usb_alloc_new_device();
-		dev->host = host;
-		usb_new_device(dev);
 	}
 
 	printf("%d USB Device(s) found\n", dev_index);