Added support for USB remote wakeup

linux_5.10/drivers/usb/dwc2/gadget.c

@@ -4306,6 +4306,78 @@ static int dwc2_hsotg_ep_dequeue(struct usb_ep *ep, struct usb_request *req)
 	return 0;
 }
 
+/**
+ * dwc2_hsotg_wakeup - send wakeup signal to the host
+ * @gadget: The usb gadget state
+ *
+ * If the gadget is in device mode and in the L1 or L2 state,
+ * it sends a wakeup signal to the host.
+ */
+static int dwc2_hsotg_wakeup(struct usb_gadget *gadget)
+{
+	struct dwc2_hsotg *hsotg = to_hsotg(gadget);
+	int ret = -1;
+	unsigned long flags;
+
+	spin_lock_irqsave(&hsotg->lock, flags);
+
+	if (!hsotg->remote_wakeup_allowed) {
+		dev_info(hsotg->dev,
+			"wakeup: signalling skipped: is not allowed by host\n");
+		goto skip;
+	}
+	if (hsotg->lx_state != DWC2_L1 && hsotg->lx_state != DWC2_L2) {
+		dev_info(hsotg->dev,
+			"wakeup: signalling skipped: gadget not in L1/L2 state: %d\n", hsotg->lx_state);
+		goto skip;
+	}
+	if (!dwc2_is_device_mode(hsotg)) {
+		dev_info(hsotg->dev,
+			"wakeup: signalling skipped: gadget not in device mode\n");
+		goto skip;
+	}
+
+	/*if (hsotg->in_ppd) {
+		if (dwc2_exit_partial_power_down(hsotg, 1, true))
+			dev_err(hsotg->dev, "wakeup: exit partial_power_down failed\n");
+		call_gadget(hsotg, resume);
+	}*/
+	if (hsotg->params.power_down == DWC2_POWER_DOWN_PARAM_NONE && hsotg->bus_suspended) {
+		u32 pcgctl;
+
+		dev_info(hsotg->dev, "wakeup: exiting device clock gating\n");
+
+		/* Clear the Gate hclk. */
+		pcgctl = dwc2_readl(hsotg, PCGCTL);
+		pcgctl &= ~PCGCTL_GATEHCLK;
+		dwc2_writel(hsotg, pcgctl, PCGCTL);
+		udelay(5);
+
+		/* Phy Clock bit. */
+		pcgctl = dwc2_readl(hsotg, PCGCTL);
+		pcgctl &= ~PCGCTL_STOPPCLK;
+		dwc2_writel(hsotg, pcgctl, PCGCTL);
+		udelay(5);
+
+		hsotg->bus_suspended = false;
+	}
+
+	dev_info(hsotg->dev, "wakeup: sending signal to the host");
+
+	dwc2_set_bit(hsotg, DCTL, DCTL_RMTWKUPSIG);
+	mdelay(10);
+	dwc2_clear_bit(hsotg, DCTL, DCTL_RMTWKUPSIG);
+
+	/* After the signalling, the USB core wakes up to L0 */
+	call_gadget(hsotg, resume);
+	hsotg->lx_state = DWC2_L0;
+
+	ret = 0;
+skip:
+	spin_unlock_irqrestore(&hsotg->lock, flags);
+	return ret;
+}
+
 /**
  * dwc2_hsotg_ep_sethalt - set halt on a given endpoint
  * @ep: The endpoint to set halt.
@@ -4688,6 +4760,7 @@ static const struct usb_gadget_ops dwc2_hsotg_gadget_ops = {
 	.pullup                 = dwc2_hsotg_pullup,
 	.vbus_session		= dwc2_hsotg_vbus_session,
 	.vbus_draw		= dwc2_hsotg_vbus_draw,
+ 	.wakeup			= dwc2_hsotg_wakeup,
 };
 
 /**

linux_5.10/drivers/usb/gadget/function/f_hid.c

@@ -44,6 +44,8 @@ struct f_hidg {
 	unsigned short			report_desc_length;
 	char				*report_desc;
 	unsigned short			report_length;
+	bool				use_out_ep;
+	bool				wakeup_on_write;
 
 	/* recv report */
 	struct list_head		completed_out_req;
@@ -332,10 +334,23 @@ static ssize_t f_hidg_write(struct file *file, const char __user *buffer,
 			    size_t count, loff_t *offp)
 {
 	struct f_hidg *hidg  = file->private_data;
+	struct usb_composite_dev *cdev = hidg->func.config->cdev;
 	struct usb_request *req;
 	unsigned long flags;
 	ssize_t status = -ENOMEM;
 
+	/*
+	 * remote wakeup is allowed only when the corresponding bit
+	 * in config descriptor is set and wakeup_on_write is enabled.
+     * FIXME: cdev->config can be NULLed on disconnect.
+	 */
+	if (hidg->wakeup_on_write /*&& cdev->config->bmAttributes & 0x20*/){
+		usb_gadget_wakeup(cdev->gadget);
+		ERROR(hidg->func.config->cdev,
+			"usb_gadget_wakeup\n");
+	}
+
+
 	spin_lock_irqsave(&hidg->write_spinlock, flags);
 
 #define WRITE_COND (!hidg->write_pending)
@@ -918,6 +933,7 @@ CONFIGFS_ATTR(f_hid_opts_, name)
 F_HID_OPT(subclass, 8, 255);
 F_HID_OPT(protocol, 8, 255);
 F_HID_OPT(report_length, 16, 65535);
+F_HID_OPT(wakeup_on_write, 8, 1);
 
 static ssize_t f_hid_opts_report_desc_show(struct config_item *item, char *page)
 {
@@ -976,6 +992,7 @@ CONFIGFS_ATTR_RO(f_hid_opts_, dev);
 static struct configfs_attribute *hid_attrs[] = {
 	&f_hid_opts_attr_subclass,
 	&f_hid_opts_attr_protocol,
+	&f_hid_opts_attr_wakeup_on_write,
 	&f_hid_opts_attr_report_length,
 	&f_hid_opts_attr_report_desc,
 	&f_hid_opts_attr_dev,
@@ -1106,6 +1123,7 @@ static struct usb_function *hidg_alloc(struct usb_function_instance *fi)
 			return ERR_PTR(-ENOMEM);
 		}
 	}
+	hidg->wakeup_on_write = opts->wakeup_on_write;
 
 	mutex_unlock(&opts->lock);
 

linux_5.10/drivers/usb/gadget/function/u_hid.h

@@ -20,6 +20,7 @@ struct f_hid_opts {
 	int				minor;
 	unsigned char			subclass;
 	unsigned char			protocol;
+	unsigned char			wakeup_on_write;
 	unsigned short			report_length;
 	unsigned short			report_desc_length;
 	unsigned char			*report_desc;

linux_5.10/drivers/usb/gadget/legacy/hid.c

@@ -123,7 +123,7 @@ static struct usb_configuration config_driver = {
 	.label			= "HID Gadget",
 	.bConfigurationValue	= 1,
 	/* .iConfiguration = DYNAMIC */
-	.bmAttributes		= USB_CONFIG_ATT_SELFPOWER,
+	.bmAttributes		= USB_CONFIG_ATT_SELFPOWER | USB_CONFIG_ATT_WAKEUP,
 };
 
 /****************************** Gadget Bind ******************************/

linux_5.10/drivers/usb/gadget/udc/core.c

@@ -499,6 +499,8 @@ int usb_gadget_wakeup(struct usb_gadget *gadget)
 {
 	int ret = 0;
 
+	// printf("usb_gadget_wakeup \r\n");
+	// dev_err(dev, "usb_gadget_wakeup\n");
 	if (!gadget->ops->wakeup) {
 		ret = -EOPNOTSUPP;
 		goto out;