[RFC/PATCH 2/3] usb:gadget: Add SuperSpeed function power management

[Amit Blay <ablay@codeaurora.org>]

1. Add missing definitions in ch9.h for requests tarageted to an
Interface: GET_STATUS & SET_FEATURE(FUNC_SUSPEND).

2. Add func_wakeup api to usb_gadget_ops.
Super-Speed device must provide interface number to the UDC when
it triggers remote wakeup (function wake).
The func_wakeup api is used instead of the wakeup api, when the
gadget is connected in Super-Speed. The wakeup api is left as is,
and it is used when the gadget is connected in High-Speed. Therefore,
no change is required in non Super-Speed UDCs.

Signed-off-by: Amit Blay <ablay@codeaurora.org>

---
 drivers/usb/gadget/udc-core.c |    2 +-
 drivers/usb/gadget/zero.c     |    6 +++++-
 include/linux/usb/ch9.h       |    8 ++++++++
 include/linux/usb/gadget.h    |   35 +++++++++++++++++++++++++++--------
 4 files changed, 41 insertions(+), 10 deletions(-)

diff --git a/drivers/usb/gadget/udc-core.c b/drivers/usb/gadget/udc-core.c
index 05ba472..beb7e89 100644
--- a/drivers/usb/gadget/udc-core.c
+++ b/drivers/usb/gadget/udc-core.c
@@ -347,7 +347,7 @@ static ssize_t usb_udc_srp_store(struct device *dev,
 	struct usb_udc		*udc = dev_get_drvdata(dev);
 
 	if (sysfs_streq(buf, "1"))
-		usb_gadget_wakeup(udc->gadget);
+		usb_gadget_wakeup(udc->gadget, 0);
 
 	return n;
 }
diff --git a/drivers/usb/gadget/zero.c b/drivers/usb/gadget/zero.c
index 00e2fd2..a5d13c6 100644
--- a/drivers/usb/gadget/zero.c
+++ b/drivers/usb/gadget/zero.c
@@ -239,7 +239,11 @@ static void zero_autoresume(unsigned long _c)
 	 * because of some direct user request.
 	 */
 	if (g->speed != USB_SPEED_UNKNOWN) {
-		int status = usb_gadget_wakeup(g);
+		/*
+		 * The single interface of the current configuration
+		 * triggers the wakeup.
+		 */
+		int status = usb_gadget_wakeup(g, 1);
 		INFO(cdev, "%s --> %d\n", __func__, status);
 	}
 }
diff --git a/include/linux/usb/ch9.h b/include/linux/usb/ch9.h
index 0fd3fbd..404c10e 100644
--- a/include/linux/usb/ch9.h
+++ b/include/linux/usb/ch9.h
@@ -142,7 +142,13 @@
 #define USB_DEVICE_LTM_ENABLE	50	/* dev may send LTM */
 #define USB_INTRF_FUNC_SUSPEND	0	/* function suspend */
 
+/*
+ * Function Suspend Options as defined by USB 3.0
+ * See USB 3.0 spec Table 9-7
+ */
 #define USB_INTR_FUNC_SUSPEND_OPT_MASK	0xFF00
+#define USB_INTR_FUNC_SUSPEND_SUSP		1 /* function suspend option */
+#define USB_INTR_FUNC_SUSPEND_RWAKE_EN	2 /* function wake enabled option */
 
 #define USB_ENDPOINT_HALT		0	/* IN/OUT will STALL */
 
@@ -150,6 +156,8 @@
 #define USB_DEV_STAT_U1_ENABLED		2	/* transition into U1 state */
 #define USB_DEV_STAT_U2_ENABLED		3	/* transition into U2 state */
 #define USB_DEV_STAT_LTM_ENABLED	4	/* Latency tolerance messages */
+#define USB_INTR_STAT_RWAKE_CAP		0	/* Function wake capable */
+#define USB_INTR_STAT_RWAKE_EN			1	/* Function wake enabled */
 
 /**
  * struct usb_ctrlrequest - SETUP data for a USB device control request
diff --git a/include/linux/usb/gadget.h b/include/linux/usb/gadget.h
index 087f4b9..3ebbc11 100644
--- a/include/linux/usb/gadget.h
+++ b/include/linux/usb/gadget.h
@@ -458,7 +458,11 @@ struct usb_gadget_ops {
 	int	(*pullup) (struct usb_gadget *, int is_on);
 	int	(*ioctl)(struct usb_gadget *,
 				unsigned code, unsigned long param);
+
+	/* USB 3.0 additions */
 	void	(*get_config_params)(struct usb_dcd_config_params *);
+	int     (*func_wakeup)(struct usb_gadget *, int interface_id);
+
 	int	(*udc_start)(struct usb_gadget *,
 			struct usb_gadget_driver *);
 	int	(*udc_stop)(struct usb_gadget *,
@@ -607,21 +611,36 @@ static inline int usb_gadget_frame_number(struct usb_gadget *gadget)
 /**
  * usb_gadget_wakeup - tries to wake up the host connected to this gadget
  * @gadget: controller used to wake up the host
+ * @interface_id: id of the first interface of the function that
+ *	triggered the wake up
  *
  * Returns zero on success, else negative error code if the hardware
  * doesn't support such attempts, or its support has not been enabled
  * by the usb host.  Drivers must return device descriptors that report
  * their ability to support this, or hosts won't enable it.
+ * For Super-Speed devices only, the gadget should provide the
+ * id of the first interface that triggered the wake up
+ * (function wake). For non Super-Speed devices, the value of
+ * this parameter doesn't matter.
  *
- * This may also try to use SRP to wake the host and start enumeration,
- * even if OTG isn't otherwise in use.  OTG devices may also start
- * remote wakeup even when hosts don't explicitly enable it.
+ * This may also try to use SRP to wake the host and start
+ * enumeration, even if OTG isn't otherwise in use.  OTG devices
+ * may also start remote wakeup even when hosts don't explicitly
+ * enable it.
  */
-static inline int usb_gadget_wakeup(struct usb_gadget *gadget)
+static inline int usb_gadget_wakeup(struct usb_gadget *gadget, int interface_id)
 {
-	if (!gadget->ops->wakeup)
-		return -EOPNOTSUPP;
-	return gadget->ops->wakeup(gadget);
+	if (gadget->speed == USB_SPEED_SUPER) {
+		if (!gadget->ops->func_wakeup)
+			return -EOPNOTSUPP;
+
+		return gadget->ops->func_wakeup(gadget, interface_id);
+	} else {
+		if (!gadget->ops->wakeup)
+			return -EOPNOTSUPP;
+
+		return gadget->ops->wakeup(gadget);
+	}
 }
 
 /**
-- 
1.7.3.3

--
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The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum.