1 // SPDX-License-Identifier: GPL-2.0
3  * drd.c - DesignWare USB2 DRD Controller Dual-role support
13 #include <linux/usb/role.h>
21 	spin_lock_irqsave(&hsotg->lock, flags);  in dwc2_ovr_init()
29 	spin_unlock_irqrestore(&hsotg->lock, flags);  in dwc2_ovr_init()
31 	dwc2_force_mode(hsotg, (hsotg->dr_mode == USB_DR_MODE_HOST));  in dwc2_ovr_init()
38 	/* Check if A-Session is already in the right state */  in dwc2_ovr_avalid()
41 		return -EALREADY;  in dwc2_ovr_avalid()
57 	/* Check if B-Session is already in the right state */  in dwc2_ovr_bvalid()
60 		return -EALREADY;  in dwc2_ovr_bvalid()
72 static int dwc2_drd_role_sw_set(struct usb_role_switch *sw, enum usb_role role)  in dwc2_drd_role_sw_set()  argument
79 	if ((role == USB_ROLE_DEVICE && hsotg->dr_mode == USB_DR_MODE_HOST) ||  in dwc2_drd_role_sw_set()
80 	    (role == USB_ROLE_HOST && hsotg->dr_mode == USB_DR_MODE_PERIPHERAL))  in dwc2_drd_role_sw_set()
81 		return -EINVAL;  in dwc2_drd_role_sw_set()
86 	if (role == USB_ROLE_NONE && hsotg->test_mode) {  in dwc2_drd_role_sw_set()
87 		dev_dbg(hsotg->dev, "Core is in test mode\n");  in dwc2_drd_role_sw_set()
88 		return -EBUSY;  in dwc2_drd_role_sw_set()
95 	 * If role-switch set is called before the udc_start, we need to enable  in dwc2_drd_role_sw_set()
99 	if (!hsotg->ll_hw_enabled && hsotg->clk) {  in dwc2_drd_role_sw_set()
100 		int ret = clk_prepare_enable(hsotg->clk);  in dwc2_drd_role_sw_set()
106 	spin_lock_irqsave(&hsotg->lock, flags);  in dwc2_drd_role_sw_set()
108 	if (role == USB_ROLE_HOST) {  in dwc2_drd_role_sw_set()
110 	} else if (role == USB_ROLE_DEVICE) {  in dwc2_drd_role_sw_set()
124 	spin_unlock_irqrestore(&hsotg->lock, flags);  in dwc2_drd_role_sw_set()
126 	if (!already && hsotg->dr_mode == USB_DR_MODE_OTG)  in dwc2_drd_role_sw_set()
128 		dwc2_force_mode(hsotg, role == USB_ROLE_HOST);  in dwc2_drd_role_sw_set()
130 	if (!hsotg->ll_hw_enabled && hsotg->clk)  in dwc2_drd_role_sw_set()
131 		clk_disable_unprepare(hsotg->clk);  in dwc2_drd_role_sw_set()
133 	dev_dbg(hsotg->dev, "%s-session valid\n",  in dwc2_drd_role_sw_set()
134 		role == USB_ROLE_NONE ? "No" :  in dwc2_drd_role_sw_set()
135 		role == USB_ROLE_HOST ? "A" : "B");  in dwc2_drd_role_sw_set()
146 	if (!device_property_read_bool(hsotg->dev, "usb-role-switch"))  in dwc2_drd_init()
150 	role_sw_desc.fwnode = dev_fwnode(hsotg->dev);  in dwc2_drd_init()
154 	role_sw = usb_role_switch_register(hsotg->dev, &role_sw_desc);  in dwc2_drd_init()
157 		dev_err(hsotg->dev,  in dwc2_drd_init()
158 			"failed to register role switch: %d\n", ret);  in dwc2_drd_init()
162 	hsotg->role_sw = role_sw;  in dwc2_drd_init()
174 	if (hsotg->role_sw && !hsotg->params.external_id_pin_ctl) {  in dwc2_drd_suspend()
187 	if (hsotg->role_sw && !hsotg->params.external_id_pin_ctl) {  in dwc2_drd_resume()
198 	if (hsotg->role_sw)  in dwc2_drd_exit()
199 		usb_role_switch_unregister(hsotg->role_sw);  in dwc2_drd_exit()