USB: xhci: Support USB hubs.

For a USB hub to work under an xHCI host controller, the xHC's internal
scheduler must be made aware of the hub's characteristics.  Add an xHCI
hook that the USB core will call after it fetches the hub descriptor.
This hook will add hub information to the slot context for that device,
including whether it has multiple TTs or a single TT, the number of ports
on the hub, and TT think time.

Setting up the slot context for the device is different for 0.95 and 0.96
xHCI host controllers.

Some of the slot context reserved fields in the 0.95 specification were
changed into hub fields in the 0.96 specification.  Don't set the TT think
time or number of ports for a hub if we're dealing with a 0.95-compliant
xHCI host controller.

The 0.95 xHCI specification says that to modify the hub flag, we need to
issue an evaluate context command.  The 0.96 specification says that flag
can be set with a configure endpoint command.  Issue the correct command
based on the version reported by the hardware.

This patch does not add support for multi-TT hubs.  Multi-TT hubs expose
a single TT on alt setting 0, and multi-TT on alt setting 1.  The xHCI
driver can't handle setting alternate interfaces yet.

Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

1 files changed, 82 insertions, 0 deletions

diff --git a/drivers/usb/host/xhci-hcd.c b/drivers/usb/host/xhci-hcd.c
index 2fcc360f064..99911e727e0 100644
--- a/drivers/usb/host/xhci-hcd.c
+++ b/drivers/usb/host/xhci-hcd.c
@@ -1594,6 +1594,88 @@ int xhci_address_device(struct usb_hcd *hcd, struct usb_device *udev)
 	return 0;
 }
 
+/* Once a hub descriptor is fetched for a device, we need to update the xHC's
+ * internal data structures for the device.
+ */
+int xhci_update_hub_device(struct usb_hcd *hcd, struct usb_device *hdev,
+			struct usb_tt *tt, gfp_t mem_flags)
+{
+	struct xhci_hcd *xhci = hcd_to_xhci(hcd);
+	struct xhci_virt_device *vdev;
+	struct xhci_command *config_cmd;
+	struct xhci_input_control_ctx *ctrl_ctx;
+	struct xhci_slot_ctx *slot_ctx;
+	unsigned long flags;
+	unsigned think_time;
+	int ret;
+
+	/* Ignore root hubs */
+	if (!hdev->parent)
+		return 0;
+
+	vdev = xhci->devs[hdev->slot_id];
+	if (!vdev) {
+		xhci_warn(xhci, "Cannot update hub desc for unknown device.\n");
+		return -EINVAL;
+	}
+	config_cmd = xhci_alloc_command(xhci, true, mem_flags);
+	if (!config_cmd) {
+		xhci_dbg(xhci, "Could not allocate xHCI command structure.\n");
+		return -ENOMEM;
+	}
+
+	spin_lock_irqsave(&xhci->lock, flags);
+	xhci_slot_copy(xhci, config_cmd->in_ctx, vdev->out_ctx);
+	ctrl_ctx = xhci_get_input_control_ctx(xhci, config_cmd->in_ctx);
+	ctrl_ctx->add_flags |= SLOT_FLAG;
+	slot_ctx = xhci_get_slot_ctx(xhci, config_cmd->in_ctx);
+	slot_ctx->dev_info |= DEV_HUB;
+	if (tt->multi)
+		slot_ctx->dev_info |= DEV_MTT;
+	if (xhci->hci_version > 0x95) {
+		xhci_dbg(xhci, "xHCI version %x needs hub "
+				"TT think time and number of ports\n",
+				(unsigned int) xhci->hci_version);
+		slot_ctx->dev_info2 |= XHCI_MAX_PORTS(hdev->maxchild);
+		/* Set TT think time - convert from ns to FS bit times.
+		 * 0 = 8 FS bit times, 1 = 16 FS bit times,
+		 * 2 = 24 FS bit times, 3 = 32 FS bit times.
+		 */
+		think_time = tt->think_time;
+		if (think_time != 0)
+			think_time = (think_time / 666) - 1;
+		slot_ctx->tt_info |= TT_THINK_TIME(think_time);
+	} else {
+		xhci_dbg(xhci, "xHCI version %x doesn't need hub "
+				"TT think time or number of ports\n",
+				(unsigned int) xhci->hci_version);
+	}
+	slot_ctx->dev_state = 0;
+	spin_unlock_irqrestore(&xhci->lock, flags);
+
+	xhci_dbg(xhci, "Set up %s for hub device.\n",
+			(xhci->hci_version > 0x95) ?
+			"configure endpoint" : "evaluate context");
+	xhci_dbg(xhci, "Slot %u Input Context:\n", hdev->slot_id);
+	xhci_dbg_ctx(xhci, config_cmd->in_ctx, 0);
+
+	/* Issue and wait for the configure endpoint or
+	 * evaluate context command.
+	 */
+	if (xhci->hci_version > 0x95)
+		ret = xhci_configure_endpoint(xhci, hdev, config_cmd,
+				false, false);
+	else
+		ret = xhci_configure_endpoint(xhci, hdev, config_cmd,
+				true, false);
+
+	xhci_dbg(xhci, "Slot %u Output Context:\n", hdev->slot_id);
+	xhci_dbg_ctx(xhci, vdev->out_ctx, 0);
+
+	xhci_free_command(xhci, config_cmd);
+	return ret;
+}
+
 int xhci_get_frame(struct usb_hcd *hcd)
 {
 	struct xhci_hcd *xhci = hcd_to_xhci(hcd);