1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * otg.c - ChipIdea USB IP core OTG driver 4 * 5 * Copyright (C) 2013 Freescale Semiconductor, Inc. 6 * 7 * Author: Peter Chen 8 */ 9 10 /* 11 * This file mainly handles otgsc register, OTG fsm operations for HNP and SRP 12 * are also included. 13 */ 14 15 #include <linux/usb/otg.h> 16 #include <linux/usb/gadget.h> 17 #include <linux/usb/chipidea.h> 18 19 #include "ci.h" 20 #include "bits.h" 21 #include "otg.h" 22 #include "otg_fsm.h" 23 24 /** 25 * hw_read_otgsc - returns otgsc register bits value. 26 * @ci: the controller 27 * @mask: bitfield mask 28 */ 29 u32 hw_read_otgsc(struct ci_hdrc *ci, u32 mask) 30 { 31 struct ci_hdrc_cable *cable; 32 u32 val = hw_read(ci, OP_OTGSC, mask); 33 34 /* 35 * If using extcon framework for VBUS and/or ID signal 36 * detection overwrite OTGSC register value 37 */ 38 cable = &ci->platdata->vbus_extcon; 39 if (!IS_ERR(cable->edev) || ci->role_switch) { 40 if (cable->changed) 41 val |= OTGSC_BSVIS; 42 else 43 val &= ~OTGSC_BSVIS; 44 45 if (cable->connected) 46 val |= OTGSC_BSV; 47 else 48 val &= ~OTGSC_BSV; 49 50 if (cable->enabled) 51 val |= OTGSC_BSVIE; 52 else 53 val &= ~OTGSC_BSVIE; 54 } 55 56 cable = &ci->platdata->id_extcon; 57 if (!IS_ERR(cable->edev) || ci->role_switch) { 58 if (cable->changed) 59 val |= OTGSC_IDIS; 60 else 61 val &= ~OTGSC_IDIS; 62 63 if (cable->connected) 64 val &= ~OTGSC_ID; /* host */ 65 else 66 val |= OTGSC_ID; /* device */ 67 68 if (cable->enabled) 69 val |= OTGSC_IDIE; 70 else 71 val &= ~OTGSC_IDIE; 72 } 73 74 return val & mask; 75 } 76 77 /** 78 * hw_write_otgsc - updates target bits of OTGSC register. 79 * @ci: the controller 80 * @mask: bitfield mask 81 * @data: to be written 82 */ 83 void hw_write_otgsc(struct ci_hdrc *ci, u32 mask, u32 data) 84 { 85 struct ci_hdrc_cable *cable; 86 87 cable = &ci->platdata->vbus_extcon; 88 if (!IS_ERR(cable->edev) || ci->role_switch) { 89 if (data & mask & OTGSC_BSVIS) 90 cable->changed = false; 91 92 /* Don't enable vbus interrupt if using external notifier */ 93 if (data & mask & OTGSC_BSVIE) { 94 cable->enabled = true; 95 data &= ~OTGSC_BSVIE; 96 } else if (mask & OTGSC_BSVIE) { 97 cable->enabled = false; 98 } 99 } 100 101 cable = &ci->platdata->id_extcon; 102 if (!IS_ERR(cable->edev) || ci->role_switch) { 103 if (data & mask & OTGSC_IDIS) 104 cable->changed = false; 105 106 /* Don't enable id interrupt if using external notifier */ 107 if (data & mask & OTGSC_IDIE) { 108 cable->enabled = true; 109 data &= ~OTGSC_IDIE; 110 } else if (mask & OTGSC_IDIE) { 111 cable->enabled = false; 112 } 113 } 114 115 hw_write(ci, OP_OTGSC, mask | OTGSC_INT_STATUS_BITS, data); 116 } 117 118 /** 119 * ci_otg_role - pick role based on ID pin state 120 * @ci: the controller 121 */ 122 enum ci_role ci_otg_role(struct ci_hdrc *ci) 123 { 124 enum ci_role role = hw_read_otgsc(ci, OTGSC_ID) 125 ? CI_ROLE_GADGET 126 : CI_ROLE_HOST; 127 128 return role; 129 } 130 131 void ci_handle_vbus_change(struct ci_hdrc *ci) 132 { 133 if (!ci->is_otg) { 134 if (ci->platdata->flags & CI_HDRC_FORCE_VBUS_ACTIVE_ALWAYS) 135 usb_gadget_vbus_connect(&ci->gadget); 136 return; 137 } 138 139 if (hw_read_otgsc(ci, OTGSC_BSV) && !ci->vbus_active) 140 usb_gadget_vbus_connect(&ci->gadget); 141 else if (!hw_read_otgsc(ci, OTGSC_BSV) && ci->vbus_active) 142 usb_gadget_vbus_disconnect(&ci->gadget); 143 } 144 145 /** 146 * hw_wait_vbus_lower_bsv - When we switch to device mode, the vbus value 147 * should be lower than OTGSC_BSV before connecting 148 * to host. 149 * 150 * @ci: the controller 151 * 152 * This function returns an error code if timeout 153 */ 154 static int hw_wait_vbus_lower_bsv(struct ci_hdrc *ci) 155 { 156 unsigned long elapse = jiffies + msecs_to_jiffies(5000); 157 u32 mask = OTGSC_BSV; 158 159 while (hw_read_otgsc(ci, mask)) { 160 if (time_after(jiffies, elapse)) { 161 dev_err(ci->dev, "timeout waiting for %08x in OTGSC\n", 162 mask); 163 return -ETIMEDOUT; 164 } 165 msleep(20); 166 } 167 168 return 0; 169 } 170 171 void ci_handle_id_switch(struct ci_hdrc *ci) 172 { 173 enum ci_role role; 174 175 mutex_lock(&ci->mutex); 176 role = ci_otg_role(ci); 177 if (role != ci->role) { 178 dev_dbg(ci->dev, "switching from %s to %s\n", 179 ci_role(ci)->name, ci->roles[role]->name); 180 181 if (ci->vbus_active && ci->role == CI_ROLE_GADGET) 182 /* 183 * vbus disconnect event is lost due to role 184 * switch occurs during system suspend. 185 */ 186 usb_gadget_vbus_disconnect(&ci->gadget); 187 188 ci_role_stop(ci); 189 190 if (role == CI_ROLE_GADGET && 191 IS_ERR(ci->platdata->vbus_extcon.edev)) 192 /* 193 * Wait vbus lower than OTGSC_BSV before connecting 194 * to host. If connecting status is from an external 195 * connector instead of register, we don't need to 196 * care vbus on the board, since it will not affect 197 * external connector status. 198 */ 199 hw_wait_vbus_lower_bsv(ci); 200 201 ci_role_start(ci, role); 202 /* vbus change may have already occurred */ 203 if (role == CI_ROLE_GADGET) 204 ci_handle_vbus_change(ci); 205 } 206 mutex_unlock(&ci->mutex); 207 } 208 /** 209 * ci_otg_work - perform otg (vbus/id) event handle 210 * @work: work struct 211 */ 212 static void ci_otg_work(struct work_struct *work) 213 { 214 struct ci_hdrc *ci = container_of(work, struct ci_hdrc, work); 215 216 if (ci_otg_is_fsm_mode(ci) && !ci_otg_fsm_work(ci)) { 217 enable_irq(ci->irq); 218 return; 219 } 220 221 pm_runtime_get_sync(ci->dev); 222 223 if (ci->id_event) { 224 ci->id_event = false; 225 ci_handle_id_switch(ci); 226 } 227 228 if (ci->b_sess_valid_event) { 229 ci->b_sess_valid_event = false; 230 ci_handle_vbus_change(ci); 231 } 232 233 pm_runtime_put_sync(ci->dev); 234 235 enable_irq(ci->irq); 236 } 237 238 239 /** 240 * ci_hdrc_otg_init - initialize otg struct 241 * @ci: the controller 242 */ 243 int ci_hdrc_otg_init(struct ci_hdrc *ci) 244 { 245 INIT_WORK(&ci->work, ci_otg_work); 246 ci->wq = create_freezable_workqueue("ci_otg"); 247 if (!ci->wq) { 248 dev_err(ci->dev, "can't create workqueue\n"); 249 return -ENODEV; 250 } 251 252 if (ci_otg_is_fsm_mode(ci)) 253 return ci_hdrc_otg_fsm_init(ci); 254 255 return 0; 256 } 257 258 /** 259 * ci_hdrc_otg_destroy - destroy otg struct 260 * @ci: the controller 261 */ 262 void ci_hdrc_otg_destroy(struct ci_hdrc *ci) 263 { 264 if (ci->wq) 265 destroy_workqueue(ci->wq); 266 267 /* Disable all OTG irq and clear status */ 268 hw_write_otgsc(ci, OTGSC_INT_EN_BITS | OTGSC_INT_STATUS_BITS, 269 OTGSC_INT_STATUS_BITS); 270 if (ci_otg_is_fsm_mode(ci)) 271 ci_hdrc_otg_fsm_remove(ci); 272 } 273