[U-Boot] [RFC 3/4] dm: usb: Store usb_device parent pointer in usb_device

[Hans de Goede]

When calling into the hcd code in usb_scan_device() we do not yet have
the actual udevice for the device we are scanning, so we temporarily set
usb_device.dev to the parent.

This means that we cannot use usb_device.dev to accurately determine our
place in the usb topology when reading descriptors, and this is necessary
to correctly program the usb-2 hub tt settings when a usb-1 device is
connected to a usb-2 hub.

This commit (re)adds a direct parent usb_device pointer to struct usb_device
so that the usb hcd code can get to the usb_device parent without needing to
go through the dm.

This fixes usb-1 devices plugged into usb-2 hubs not working with the driver
model.

Signed-off-by: Hans de Goede <hdegoede at redhat.com>
---
 drivers/usb/host/ehci-hcd.c   | 24 +-----------------------
 drivers/usb/host/usb-uclass.c |  5 ++---
 include/usb.h                 |  2 +-
 3 files changed, 4 insertions(+), 27 deletions(-)

diff --git a/drivers/usb/host/ehci-hcd.c b/drivers/usb/host/ehci-hcd.c
index 19f1e29..00c038c 100644
--- a/drivers/usb/host/ehci-hcd.c
+++ b/drivers/usb/host/ehci-hcd.c
@@ -292,7 +292,6 @@ static void ehci_update_endpt2_dev_n_port(struct usb_device *udev,
 					  struct QH *qh)
 {
 	struct usb_device *ttdev;
-	int parent_devnum;
 
 	if (udev->speed != USB_SPEED_LOW && udev->speed != USB_SPEED_FULL)
 		return;
@@ -302,35 +301,14 @@ static void ehci_update_endpt2_dev_n_port(struct usb_device *udev,
 	 * the tt, so of the first upstream usb-2 hub, there may be usb-1 hubs
 	 * in the tree before that one!
 	 */
-#ifdef CONFIG_DM_USB
-	struct udevice *parent;
-
-	for (ttdev = udev; ; ) {
-		struct udevice *dev = ttdev->dev;
-
-		if (dev->parent &&
-		    device_get_uclass_id(dev->parent) == UCLASS_USB_HUB)
-			parent = dev->parent;
-		else
-			parent = NULL;
-		if (!parent)
-			return;
-		ttdev = dev_get_parentdata(parent);
-		if (!ttdev->speed != USB_SPEED_HIGH)
-			break;
-	}
-	parent_devnum = ttdev->devnum;
-#else
 	ttdev = udev;
 	while (ttdev->parent && ttdev->parent->speed != USB_SPEED_HIGH)
 		ttdev = ttdev->parent;
 	if (!ttdev->parent)
 		return;
-	parent_devnum = ttdev->parent->devnum;
-#endif
 
 	qh->qh_endpt2 |= cpu_to_hc32(QH_ENDPT2_PORTNUM(ttdev->portnr) |
-				     QH_ENDPT2_HUBADDR(parent_devnum));
+				     QH_ENDPT2_HUBADDR(ttdev->parent->devnum));
 }
 
 static int
diff --git a/drivers/usb/host/usb-uclass.c b/drivers/usb/host/usb-uclass.c
index 95e371d..0157bc6 100644
--- a/drivers/usb/host/usb-uclass.c
+++ b/drivers/usb/host/usb-uclass.c
@@ -470,7 +470,6 @@ int usb_scan_device(struct udevice *parent, int port,
 	bool created = false;
 	struct usb_dev_platdata *plat;
 	struct usb_bus_priv *priv;
-	struct usb_device *parent_udev;
 	int ret;
 	ALLOC_CACHE_ALIGN_BUFFER(struct usb_device, udev, 1);
 	struct usb_interface_descriptor *iface = &udev->config.if_desc[0].desc;
@@ -515,9 +514,9 @@ int usb_scan_device(struct udevice *parent, int port,
 	udev->devnum = priv->next_addr + 1;
 	udev->portnr = port;
 	debug("Calling usb_setup_device(), portnr=%d\n", udev->portnr);
-	parent_udev = device_get_uclass_id(parent) == UCLASS_USB_HUB ?
+	udev->parent = device_get_uclass_id(parent) == UCLASS_USB_HUB ?
 		dev_get_parentdata(parent) : NULL;
-	ret = usb_setup_device(udev, priv->desc_before_addr, parent_udev, port);
+	ret = usb_setup_device(udev, priv->desc_before_addr, udev->parent, port);
 	debug("read_descriptor for '%s': ret=%d\n", parent->name, ret);
 	if (ret)
 		return ret;
diff --git a/include/usb.h b/include/usb.h
index 1b667ff..7876df4 100644
--- a/include/usb.h
+++ b/include/usb.h
@@ -141,9 +141,9 @@ struct usb_device {
 	int act_len;			/* transfered bytes */
 	int maxchild;			/* Number of ports if hub */
 	int portnr;			/* Port number, 1=first */
-#ifndef CONFIG_DM_USB
 	/* parent hub, or NULL if this is the root hub */
 	struct usb_device *parent;
+#ifndef CONFIG_DM_USB
 	struct usb_device *children[USB_MAXCHILDREN];
 	void *controller;		/* hardware controller private data */
 #endif
-- 
2.3.6