usb: Add remote wakeup support

This commit adds support for remote wakeup and extends USB api
with a wakeup request call. Remote wakeup can be dsabled in kconfig
when a specific driver does not support this feature.

Signed-off-by: Paweł Zadrożniak <pawel.zadrozniak@nordicsemi.no>

include/drivers/usb/usb_dc.h

@@ -392,6 +392,15 @@ int usb_dc_ep_read_continue(u8_t ep);
  */
 int usb_dc_ep_mps(u8_t ep);
 
+/**
+ * @brief Start the host wake up procedure.
+ *
+ * Function to wake up the host if it's currently in sleep mode.
+ *
+ * @return 0 on success, negative errno code on fail.
+ */
+int usb_dc_wakeup_request(void);
+
 /**
  * @}
  */

include/usb/usb_common.h

@@ -96,7 +96,10 @@
  * D5:Remote Wakeup -> 0,
  * D4...0:Reserved -> 0
  */
-#define USB_CONFIGURATION_ATTRIBUTES	0xC0
+#define USB_CONFIGURATION_ATTRIBUTES_REMOTE_WAKEUP  0x20
+#define USB_CONFIGURATION_ATTRIBUTES                0xC0       \
+	| (COND_CODE_1(CONFIG_USB_DEVICE_REMOTE_WAKEUP,        \
+	   (USB_CONFIGURATION_ATTRIBUTES_REMOTE_WAKEUP), (0)))
 
 /* Classes */
 #define COMMUNICATION_DEVICE_CLASS	0x02

include/usb/usb_device.h

@@ -418,6 +418,18 @@ int usb_transfer_sync(u8_t ep, u8_t *data, size_t dlen, unsigned int flags);
  */
 void usb_cancel_transfer(u8_t ep);
 
+/**
+ * @brief Start the USB remote wakeup procedure
+ *
+ * Function to request a remote wakeup.
+ * This feature must be enabled in configuration, otherwise
+ * it will always return -ENOTSUP error.
+ *
+ * @return 0 on success, negative errno code on fail,
+ *         i.e. when the bus is already active.
+ */
+int usb_wakeup_request(void);
+
 /**
  * @}
  */

include/usb/usbstruct.h

@@ -71,6 +71,9 @@
 #define FEA_REMOTE_WAKEUP           0x01
 #define FEA_TEST_MODE               0x02
 
+#define DEVICE_STATUS_SELF_POWERED  0x01
+#define DEVICE_STATUS_REMOTE_WAKEUP 0x02
+
 /*
  *  USB descriptors
  */

subsys/usb/Kconfig

@@ -64,6 +64,11 @@ config USB_COMPOSITE_BUFFER_SIZE
 config USB_DEVICE_SOF
 	bool "Enable Start of Frame processing in events"
 
+config USB_DEVICE_REMOTE_WAKEUP
+	bool "Enable support for remote wakeup"
+	help
+	  This option requires USBD peripheral driver to also support remote wakeup.
+
 config USB_DEVICE_BOS
 	bool "Enable USB Binary Device Object Store (BOS)"
 

subsys/usb/usb_device.c

@@ -162,6 +162,8 @@ static struct usb_dev_priv {
 	bool enabled;
 	/** Currently selected configuration */
 	u8_t configuration;
+	/** Remote wakeup feature status */
+	bool remote_wakeup;
 	/** Transfer list */
 	struct usb_transfer_data transfer[MAX_NUM_TRANSFERS];
 } usb_dev;
@@ -615,9 +617,15 @@ static bool usb_handle_std_device_req(struct usb_setup_packet *setup,
 	case REQ_GET_STATUS:
 		LOG_DBG("REQ_GET_STATUS");
 		/* bit 0: self-powered */
-		/* bit 1: remote wakeup = not supported */
+		/* bit 1: remote wakeup */
 		data[0] = 0U;
 		data[1] = 0U;
+
+		if (IS_ENABLED(CONFIG_USB_DEVICE_REMOTE_WAKEUP)) {
+			data[0] |= (usb_dev.remote_wakeup ?
+				    DEVICE_STATUS_REMOTE_WAKEUP : 0);
+		}
+
 		*len = 2;
 		break;
 
@@ -654,18 +662,29 @@ static bool usb_handle_std_device_req(struct usb_setup_packet *setup,
 
 	case REQ_CLEAR_FEATURE:
 		LOG_DBG("REQ_CLEAR_FEATURE");
+		ret = false;
+
+		if (IS_ENABLED(CONFIG_USB_DEVICE_REMOTE_WAKEUP)) {
+			if (value == FEA_REMOTE_WAKEUP) {
+				usb_dev.remote_wakeup = false;
+				ret = true;
+			}
+		}
 		break;
 	case REQ_SET_FEATURE:
 		LOG_DBG("REQ_SET_FEATURE");
+		ret = false;
 
+		if (IS_ENABLED(CONFIG_USB_DEVICE_REMOTE_WAKEUP)) {
 			if (value == FEA_REMOTE_WAKEUP) {
-			/* put DEVICE_REMOTE_WAKEUP code here */
+				usb_dev.remote_wakeup = true;
+				ret = true;
+			}
 		}
 
 		if (value == FEA_TEST_MODE) {
 			/* put TEST_MODE code here */
 		}
-		ret = false;
 		break;
 
 	case REQ_SET_DESCRIPTOR:
@@ -1368,6 +1387,18 @@ int usb_transfer_sync(u8_t ep, u8_t *data, size_t dlen, unsigned int flags)
 	return pdata.tsize;
 }
 
+int usb_wakeup_request(void)
+{
+	if (IS_ENABLED(CONFIG_USB_DEVICE_REMOTE_WAKEUP)) {
+		if (usb_dev.remote_wakeup) {
+			return usb_dc_wakeup_request();
+		}
+		return -EACCES;
+	} else {
+		return -ENOTSUP;
+	}
+}
+
 #ifdef CONFIG_USB_COMPOSITE_DEVICE
 
 static u8_t iface_data_buf[CONFIG_USB_COMPOSITE_BUFFER_SIZE];