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/clk.h> 11#include <linux/iopoll.h> 12#include <linux/platform_device.h> 13#include <linux/usb/role.h> 14#include "core.h" 15 16#define dwc2_ovr_gotgctl(gotgctl) \ 17 ((gotgctl) |= GOTGCTL_BVALOEN | GOTGCTL_AVALOEN | GOTGCTL_VBVALOEN | \ 18 GOTGCTL_DBNCE_FLTR_BYPASS) 19 20static void dwc2_ovr_init(struct dwc2_hsotg *hsotg) 21{ 22 unsigned long flags; 23 u32 gotgctl; 24 25 spin_lock_irqsave(&hsotg->lock, flags); 26 27 gotgctl = dwc2_readl(hsotg, GOTGCTL); 28 dwc2_ovr_gotgctl(gotgctl); 29 gotgctl &= ~(GOTGCTL_BVALOVAL | GOTGCTL_AVALOVAL | GOTGCTL_VBVALOVAL); 30 if (hsotg->role_sw_default_mode == USB_DR_MODE_HOST) 31 gotgctl |= GOTGCTL_AVALOVAL | GOTGCTL_VBVALOVAL; 32 else if (hsotg->role_sw_default_mode == USB_DR_MODE_PERIPHERAL) 33 gotgctl |= GOTGCTL_BVALOVAL | GOTGCTL_VBVALOVAL; 34 dwc2_writel(hsotg, gotgctl, GOTGCTL); 35 36 spin_unlock_irqrestore(&hsotg->lock, flags); 37 38 dwc2_force_mode(hsotg, (hsotg->dr_mode == USB_DR_MODE_HOST) || 39 (hsotg->role_sw_default_mode == USB_DR_MODE_HOST)); 40} 41 42static int dwc2_ovr_avalid(struct dwc2_hsotg *hsotg, bool valid) 43{ 44 u32 gotgctl = dwc2_readl(hsotg, GOTGCTL); 45 46 /* Check if A-Session is already in the right state */ 47 if ((valid && (gotgctl & GOTGCTL_ASESVLD)) || 48 (!valid && !(gotgctl & GOTGCTL_ASESVLD))) 49 return -EALREADY; 50 51 /* Always enable overrides to handle the resume case */ 52 dwc2_ovr_gotgctl(gotgctl); 53 54 gotgctl &= ~GOTGCTL_BVALOVAL; 55 if (valid) 56 gotgctl |= GOTGCTL_AVALOVAL | GOTGCTL_VBVALOVAL; 57 else 58 gotgctl &= ~(GOTGCTL_AVALOVAL | GOTGCTL_VBVALOVAL); 59 dwc2_writel(hsotg, gotgctl, GOTGCTL); 60 61 return 0; 62} 63 64static int dwc2_ovr_bvalid(struct dwc2_hsotg *hsotg, bool valid) 65{ 66 u32 gotgctl = dwc2_readl(hsotg, GOTGCTL); 67 68 /* Check if B-Session is already in the right state */ 69 if ((valid && (gotgctl & GOTGCTL_BSESVLD)) || 70 (!valid && !(gotgctl & GOTGCTL_BSESVLD))) 71 return -EALREADY; 72 73 /* Always enable overrides to handle the resume case */ 74 dwc2_ovr_gotgctl(gotgctl); 75 76 gotgctl &= ~GOTGCTL_AVALOVAL; 77 if (valid) 78 gotgctl |= GOTGCTL_BVALOVAL | GOTGCTL_VBVALOVAL; 79 else 80 gotgctl &= ~(GOTGCTL_BVALOVAL | GOTGCTL_VBVALOVAL); 81 dwc2_writel(hsotg, gotgctl, GOTGCTL); 82 83 return 0; 84} 85 86static int dwc2_drd_role_sw_set(struct usb_role_switch *sw, enum usb_role role) 87{ 88 struct dwc2_hsotg *hsotg = usb_role_switch_get_drvdata(sw); 89 unsigned long flags; 90 int already = 0; 91 92 /* Skip session not in line with dr_mode */ 93 if ((role == USB_ROLE_DEVICE && hsotg->dr_mode == USB_DR_MODE_HOST) || 94 (role == USB_ROLE_HOST && hsotg->dr_mode == USB_DR_MODE_PERIPHERAL)) 95 return -EINVAL; 96 97#if IS_ENABLED(CONFIG_USB_DWC2_PERIPHERAL) || \ 98 IS_ENABLED(CONFIG_USB_DWC2_DUAL_ROLE) 99 /* Skip session if core is in test mode */ 100 if (role == USB_ROLE_NONE && hsotg->test_mode) { 101 dev_dbg(hsotg->dev, "Core is in test mode\n"); 102 return -EBUSY; 103 } 104#endif 105 106 /* 107 * In case of USB_DR_MODE_PERIPHERAL, clock is disabled at the end of 108 * the probe and enabled on udc_start. 109 * If role-switch set is called before the udc_start, we need to enable 110 * the clock to read/write GOTGCTL and GUSBCFG registers to override 111 * mode and sessions. It is the case if cable is plugged at boot. 112 */ 113 if (!hsotg->ll_hw_enabled && hsotg->clk) { 114 int ret = clk_prepare_enable(hsotg->clk); 115 116 if (ret) 117 return ret; 118 } 119 120 spin_lock_irqsave(&hsotg->lock, flags); 121 122 if (role == USB_ROLE_NONE) { 123 /* default operation mode when usb role is USB_ROLE_NONE */ 124 if (hsotg->role_sw_default_mode == USB_DR_MODE_HOST) 125 role = USB_ROLE_HOST; 126 else if (hsotg->role_sw_default_mode == USB_DR_MODE_PERIPHERAL) 127 role = USB_ROLE_DEVICE; 128 } 129 130 if (role == USB_ROLE_HOST) { 131 already = dwc2_ovr_avalid(hsotg, true); 132 } else if (role == USB_ROLE_DEVICE) { 133 already = dwc2_ovr_bvalid(hsotg, true); 134 if (dwc2_is_device_enabled(hsotg)) { 135 /* This clear DCTL.SFTDISCON bit */ 136 dwc2_hsotg_core_connect(hsotg); 137 } 138 } else { 139 if (dwc2_is_device_mode(hsotg)) { 140 if (!dwc2_ovr_bvalid(hsotg, false)) 141 /* This set DCTL.SFTDISCON bit */ 142 dwc2_hsotg_core_disconnect(hsotg); 143 } else { 144 dwc2_ovr_avalid(hsotg, false); 145 } 146 } 147 148 spin_unlock_irqrestore(&hsotg->lock, flags); 149 150 if (!already && hsotg->dr_mode == USB_DR_MODE_OTG) 151 /* This will raise a Connector ID Status Change Interrupt */ 152 dwc2_force_mode(hsotg, role == USB_ROLE_HOST); 153 154 if (!hsotg->ll_hw_enabled && hsotg->clk) 155 clk_disable_unprepare(hsotg->clk); 156 157 dev_dbg(hsotg->dev, "%s-session valid\n", 158 role == USB_ROLE_NONE ? "No" : 159 role == USB_ROLE_HOST ? "A" : "B"); 160 161 return 0; 162} 163 164int dwc2_drd_init(struct dwc2_hsotg *hsotg) 165{ 166 struct usb_role_switch_desc role_sw_desc = {0}; 167 struct usb_role_switch *role_sw; 168 int ret; 169 170 if (!device_property_read_bool(hsotg->dev, "usb-role-switch")) 171 return 0; 172 173 hsotg->role_sw_default_mode = usb_get_role_switch_default_mode(hsotg->dev); 174 role_sw_desc.driver_data = hsotg; 175 role_sw_desc.fwnode = dev_fwnode(hsotg->dev); 176 role_sw_desc.set = dwc2_drd_role_sw_set; 177 role_sw_desc.allow_userspace_control = true; 178 179 role_sw = usb_role_switch_register(hsotg->dev, &role_sw_desc); 180 if (IS_ERR(role_sw)) { 181 ret = PTR_ERR(role_sw); 182 dev_err(hsotg->dev, 183 "failed to register role switch: %d\n", ret); 184 return ret; 185 } 186 187 hsotg->role_sw = role_sw; 188 189 /* Enable override and initialize values */ 190 dwc2_ovr_init(hsotg); 191 192 return 0; 193} 194 195void dwc2_drd_suspend(struct dwc2_hsotg *hsotg) 196{ 197 u32 gintsts, gintmsk; 198 199 if (hsotg->role_sw && !hsotg->params.external_id_pin_ctl) { 200 gintmsk = dwc2_readl(hsotg, GINTMSK); 201 gintmsk &= ~GINTSTS_CONIDSTSCHNG; 202 dwc2_writel(hsotg, gintmsk, GINTMSK); 203 gintsts = dwc2_readl(hsotg, GINTSTS); 204 dwc2_writel(hsotg, gintsts | GINTSTS_CONIDSTSCHNG, GINTSTS); 205 } 206} 207 208void dwc2_drd_resume(struct dwc2_hsotg *hsotg) 209{ 210 u32 gintsts, gintmsk; 211 enum usb_role role; 212 213 if (hsotg->role_sw) { 214 /* get last known role (as the get ops isn't implemented by this driver) */ 215 role = usb_role_switch_get_role(hsotg->role_sw); 216 217 if (role == USB_ROLE_NONE) { 218 if (hsotg->role_sw_default_mode == USB_DR_MODE_HOST) 219 role = USB_ROLE_HOST; 220 else if (hsotg->role_sw_default_mode == USB_DR_MODE_PERIPHERAL) 221 role = USB_ROLE_DEVICE; 222 } 223 224 /* restore last role that may have been lost */ 225 if (role == USB_ROLE_HOST) 226 dwc2_ovr_avalid(hsotg, true); 227 else if (role == USB_ROLE_DEVICE) 228 dwc2_ovr_bvalid(hsotg, true); 229 230 dwc2_force_mode(hsotg, role == USB_ROLE_HOST); 231 232 dev_dbg(hsotg->dev, "resuming %s-session valid\n", 233 role == USB_ROLE_NONE ? "No" : 234 role == USB_ROLE_HOST ? "A" : "B"); 235 } 236 237 if (hsotg->role_sw && !hsotg->params.external_id_pin_ctl) { 238 gintsts = dwc2_readl(hsotg, GINTSTS); 239 dwc2_writel(hsotg, gintsts | GINTSTS_CONIDSTSCHNG, GINTSTS); 240 gintmsk = dwc2_readl(hsotg, GINTMSK); 241 gintmsk |= GINTSTS_CONIDSTSCHNG; 242 dwc2_writel(hsotg, gintmsk, GINTMSK); 243 } 244} 245 246void dwc2_drd_exit(struct dwc2_hsotg *hsotg) 247{ 248 if (hsotg->role_sw) 249 usb_role_switch_unregister(hsotg->role_sw); 250} 251