1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * drd.c - DesignWare USB2 DRD Controller Dual-role support 4 * 5 * Copyright (C) 2020 STMicroelectronics 6 * 7 * Author(s): Amelie Delaunay <amelie.delaunay@st.com> 8 */ 9 10 #include <linux/iopoll.h> 11 #include <linux/platform_device.h> 12 #include <linux/usb/role.h> 13 #include "core.h" 14 15 static void dwc2_ovr_init(struct dwc2_hsotg *hsotg) 16 { 17 unsigned long flags; 18 u32 gotgctl; 19 20 spin_lock_irqsave(&hsotg->lock, flags); 21 22 gotgctl = dwc2_readl(hsotg, GOTGCTL); 23 gotgctl |= GOTGCTL_BVALOEN | GOTGCTL_AVALOEN | GOTGCTL_VBVALOEN; 24 gotgctl |= GOTGCTL_DBNCE_FLTR_BYPASS; 25 gotgctl &= ~(GOTGCTL_BVALOVAL | GOTGCTL_AVALOVAL | GOTGCTL_VBVALOVAL); 26 dwc2_writel(hsotg, gotgctl, GOTGCTL); 27 28 spin_unlock_irqrestore(&hsotg->lock, flags); 29 30 dwc2_force_mode(hsotg, (hsotg->dr_mode == USB_DR_MODE_HOST)); 31 } 32 33 static int dwc2_ovr_avalid(struct dwc2_hsotg *hsotg, bool valid) 34 { 35 u32 gotgctl = dwc2_readl(hsotg, GOTGCTL); 36 37 /* Check if A-Session is already in the right state */ 38 if ((valid && (gotgctl & GOTGCTL_ASESVLD)) || 39 (!valid && !(gotgctl & GOTGCTL_ASESVLD))) 40 return -EALREADY; 41 42 if (valid) 43 gotgctl |= GOTGCTL_AVALOVAL | GOTGCTL_VBVALOVAL; 44 else 45 gotgctl &= ~(GOTGCTL_AVALOVAL | GOTGCTL_VBVALOVAL); 46 dwc2_writel(hsotg, gotgctl, GOTGCTL); 47 48 return 0; 49 } 50 51 static int dwc2_ovr_bvalid(struct dwc2_hsotg *hsotg, bool valid) 52 { 53 u32 gotgctl = dwc2_readl(hsotg, GOTGCTL); 54 55 /* Check if B-Session is already in the right state */ 56 if ((valid && (gotgctl & GOTGCTL_BSESVLD)) || 57 (!valid && !(gotgctl & GOTGCTL_BSESVLD))) 58 return -EALREADY; 59 60 if (valid) 61 gotgctl |= GOTGCTL_BVALOVAL | GOTGCTL_VBVALOVAL; 62 else 63 gotgctl &= ~(GOTGCTL_BVALOVAL | GOTGCTL_VBVALOVAL); 64 dwc2_writel(hsotg, gotgctl, GOTGCTL); 65 66 return 0; 67 } 68 69 static int dwc2_drd_role_sw_set(struct usb_role_switch *sw, enum usb_role role) 70 { 71 struct dwc2_hsotg *hsotg = usb_role_switch_get_drvdata(sw); 72 unsigned long flags; 73 int already = 0; 74 75 /* Skip session not in line with dr_mode */ 76 if ((role == USB_ROLE_DEVICE && hsotg->dr_mode == USB_DR_MODE_HOST) || 77 (role == USB_ROLE_HOST && hsotg->dr_mode == USB_DR_MODE_PERIPHERAL)) 78 return -EINVAL; 79 80 #if IS_ENABLED(CONFIG_USB_DWC2_PERIPHERAL) || \ 81 IS_ENABLED(CONFIG_USB_DWC2_DUAL_ROLE) 82 /* Skip session if core is in test mode */ 83 if (role == USB_ROLE_NONE && hsotg->test_mode) { 84 dev_dbg(hsotg->dev, "Core is in test mode\n"); 85 return -EBUSY; 86 } 87 #endif 88 89 spin_lock_irqsave(&hsotg->lock, flags); 90 91 if (role == USB_ROLE_HOST) { 92 already = dwc2_ovr_avalid(hsotg, true); 93 } else if (role == USB_ROLE_DEVICE) { 94 already = dwc2_ovr_bvalid(hsotg, true); 95 /* This clear DCTL.SFTDISCON bit */ 96 dwc2_hsotg_core_connect(hsotg); 97 } else { 98 if (dwc2_is_device_mode(hsotg)) { 99 if (!dwc2_ovr_bvalid(hsotg, false)) 100 /* This set DCTL.SFTDISCON bit */ 101 dwc2_hsotg_core_disconnect(hsotg); 102 } else { 103 dwc2_ovr_avalid(hsotg, false); 104 } 105 } 106 107 spin_unlock_irqrestore(&hsotg->lock, flags); 108 109 if (!already && hsotg->dr_mode == USB_DR_MODE_OTG) 110 /* This will raise a Connector ID Status Change Interrupt */ 111 dwc2_force_mode(hsotg, role == USB_ROLE_HOST); 112 113 dev_dbg(hsotg->dev, "%s-session valid\n", 114 role == USB_ROLE_NONE ? "No" : 115 role == USB_ROLE_HOST ? "A" : "B"); 116 117 return 0; 118 } 119 120 int dwc2_drd_init(struct dwc2_hsotg *hsotg) 121 { 122 struct usb_role_switch_desc role_sw_desc = {0}; 123 struct usb_role_switch *role_sw; 124 int ret; 125 126 if (!device_property_read_bool(hsotg->dev, "usb-role-switch")) 127 return 0; 128 129 role_sw_desc.driver_data = hsotg; 130 role_sw_desc.fwnode = dev_fwnode(hsotg->dev); 131 role_sw_desc.set = dwc2_drd_role_sw_set; 132 role_sw_desc.allow_userspace_control = true; 133 134 role_sw = usb_role_switch_register(hsotg->dev, &role_sw_desc); 135 if (IS_ERR(role_sw)) { 136 ret = PTR_ERR(role_sw); 137 dev_err(hsotg->dev, 138 "failed to register role switch: %d\n", ret); 139 return ret; 140 } 141 142 hsotg->role_sw = role_sw; 143 144 /* Enable override and initialize values */ 145 dwc2_ovr_init(hsotg); 146 147 return 0; 148 } 149 150 void dwc2_drd_suspend(struct dwc2_hsotg *hsotg) 151 { 152 u32 gintsts, gintmsk; 153 154 if (hsotg->role_sw && !hsotg->params.external_id_pin_ctl) { 155 gintmsk = dwc2_readl(hsotg, GINTMSK); 156 gintmsk &= ~GINTSTS_CONIDSTSCHNG; 157 dwc2_writel(hsotg, gintmsk, GINTMSK); 158 gintsts = dwc2_readl(hsotg, GINTSTS); 159 dwc2_writel(hsotg, gintsts | GINTSTS_CONIDSTSCHNG, GINTSTS); 160 } 161 } 162 163 void dwc2_drd_resume(struct dwc2_hsotg *hsotg) 164 { 165 u32 gintsts, gintmsk; 166 167 if (hsotg->role_sw && !hsotg->params.external_id_pin_ctl) { 168 gintsts = dwc2_readl(hsotg, GINTSTS); 169 dwc2_writel(hsotg, gintsts | GINTSTS_CONIDSTSCHNG, GINTSTS); 170 gintmsk = dwc2_readl(hsotg, GINTMSK); 171 gintmsk |= GINTSTS_CONIDSTSCHNG; 172 dwc2_writel(hsotg, gintmsk, GINTMSK); 173 } 174 } 175 176 void dwc2_drd_exit(struct dwc2_hsotg *hsotg) 177 { 178 if (hsotg->role_sw) 179 usb_role_switch_unregister(hsotg->role_sw); 180 } 181