[RFC][PATCH 2/3] usb: xhci: implement hc_driver notify entry

[Lu Baolu <baolu.lu@linux.intel.com>]

This patch implements the notify entry defined in hc_driver for xHC
driver. For HCD_MSG_DEV_SUSPEND message, it will issue stop endpoint
command for each endpoint in the device. The Suspend(SP) bit in the
command TRB will be set, which gives xHC a hint about the suspend.
For HCD_MSG_DEV_RESUME, it will ring doorbells for all endpoints
unconditionally. XHC may use these hints to optimize its operation
on endpoint state cashes.

Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
---
 drivers/usb/host/xhci-hub.c |  2 +-
 drivers/usb/host/xhci.c     | 28 ++++++++++++++++++++++++++++
 drivers/usb/host/xhci.h     |  3 +++
 3 files changed, 32 insertions(+), 1 deletion(-)

diff --git a/drivers/usb/host/xhci-hub.c b/drivers/usb/host/xhci-hub.c
index 0827d7c..a83e82e 100644
--- a/drivers/usb/host/xhci-hub.c
+++ b/drivers/usb/host/xhci-hub.c
@@ -266,7 +266,7 @@ int xhci_find_slot_id_by_port(struct usb_hcd *hcd, struct xhci_hcd *xhci,
  * to complete.
  * suspend will set to 1, if suspend bit need to set in command.
  */
-static int xhci_stop_device(struct xhci_hcd *xhci, int slot_id, int suspend)
+int xhci_stop_device(struct xhci_hcd *xhci, int slot_id, int suspend)
 {
 	struct xhci_virt_device *virt_dev;
 	struct xhci_command *cmd;
diff --git a/drivers/usb/host/xhci.c b/drivers/usb/host/xhci.c
index ec8ac16..1e4aa78 100644
--- a/drivers/usb/host/xhci.c
+++ b/drivers/usb/host/xhci.c
@@ -4917,6 +4917,29 @@ error:
 }
 EXPORT_SYMBOL_GPL(xhci_gen_setup);
 
+void xhci_notify(struct usb_hcd *hcd, struct usb_device *udev,
+		enum hcd_notification_type type, void *data)
+{
+	struct xhci_hcd	*xhci;
+
+	xhci = hcd_to_xhci(hcd);
+	if (!xhci || !xhci->devs[udev->slot_id])
+		return;
+
+	switch (type) {
+	case HCD_MSG_DEV_SUSPEND:
+		xhci_stop_device(xhci, udev->slot_id, 1);
+		break;
+	case HCD_MSG_DEV_RESUME:
+		xhci_ring_device(xhci, udev->slot_id);
+		break;
+	default:
+		xhci_dbg(xhci, "unknown notification message %d.\n", type);
+		break;
+	}
+
+}
+
 static const struct hc_driver xhci_hc_driver = {
 	.description =		"xhci-hcd",
 	.product_desc =		"xHCI Host Controller",
@@ -4976,6 +4999,11 @@ static const struct hc_driver xhci_hc_driver = {
 	.enable_usb3_lpm_timeout =	xhci_enable_usb3_lpm_timeout,
 	.disable_usb3_lpm_timeout =	xhci_disable_usb3_lpm_timeout,
 	.find_raw_port_number =	xhci_find_raw_port_number,
+
+	/*
+	 * notification call back
+	 */
+	.notify =		xhci_notify,
 };
 
 void xhci_init_driver(struct hc_driver *drv, int (*setup_fn)(struct usb_hcd *))
diff --git a/drivers/usb/host/xhci.h b/drivers/usb/host/xhci.h
index 8e421b8..f71c643 100644
--- a/drivers/usb/host/xhci.h
+++ b/drivers/usb/host/xhci.h
@@ -1867,10 +1867,13 @@ u32 xhci_port_state_to_neutral(u32 state);
 int xhci_find_slot_id_by_port(struct usb_hcd *hcd, struct xhci_hcd *xhci,
 		u16 port);
 void xhci_ring_device(struct xhci_hcd *xhci, int slot_id);
+int xhci_stop_device(struct xhci_hcd *xhci, int slot_id, int suspend);
 
 /* xHCI contexts */
 struct xhci_input_control_ctx *xhci_get_input_control_ctx(struct xhci_container_ctx *ctx);
 struct xhci_slot_ctx *xhci_get_slot_ctx(struct xhci_hcd *xhci, struct xhci_container_ctx *ctx);
 struct xhci_ep_ctx *xhci_get_ep_ctx(struct xhci_hcd *xhci, struct xhci_container_ctx *ctx, unsigned int ep_index);
 
+void xhci_notify(struct usb_hcd *hcd, struct usb_device *udev,
+		enum hcd_notification_type type, void *data);
 #endif /* __LINUX_XHCI_HCD_H */
-- 
2.1.0