1 /* 2 * OTG Finite State Machine from OTG spec 3 * 4 * Copyright (C) 2007,2008 Freescale Semiconductor, Inc. 5 * 6 * Author: Li Yang <LeoLi@freescale.com> 7 * Jerry Huang <Chang-Ming.Huang@freescale.com> 8 * 9 * This program is free software; you can redistribute it and/or modify it 10 * under the terms of the GNU General Public License as published by the 11 * Free Software Foundation; either version 2 of the License, or (at your 12 * option) any later version. 13 * 14 * This program is distributed in the hope that it will be useful, but 15 * WITHOUT ANY WARRANTY; without even the implied warranty of 16 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 17 * General Public License for more details. 18 * 19 * You should have received a copy of the GNU General Public License along 20 * with this program; if not, write to the Free Software Foundation, Inc., 21 * 675 Mass Ave, Cambridge, MA 02139, USA. 22 */ 23 24 #include <linux/module.h> 25 #include <linux/kernel.h> 26 #include <linux/types.h> 27 #include <linux/mutex.h> 28 #include <linux/delay.h> 29 #include <linux/usb.h> 30 #include <linux/usb/gadget.h> 31 #include <linux/usb/otg.h> 32 #include <linux/usb/otg-fsm.h> 33 34 /* Change USB protocol when there is a protocol change */ 35 static int otg_set_protocol(struct otg_fsm *fsm, int protocol) 36 { 37 int ret = 0; 38 39 if (fsm->protocol != protocol) { 40 VDBG("Changing role fsm->protocol= %d; new protocol= %d\n", 41 fsm->protocol, protocol); 42 /* stop old protocol */ 43 if (fsm->protocol == PROTO_HOST) 44 ret = otg_start_host(fsm, 0); 45 else if (fsm->protocol == PROTO_GADGET) 46 ret = otg_start_gadget(fsm, 0); 47 if (ret) 48 return ret; 49 50 /* start new protocol */ 51 if (protocol == PROTO_HOST) 52 ret = otg_start_host(fsm, 1); 53 else if (protocol == PROTO_GADGET) 54 ret = otg_start_gadget(fsm, 1); 55 if (ret) 56 return ret; 57 58 fsm->protocol = protocol; 59 return 0; 60 } 61 62 return 0; 63 } 64 65 /* Called when leaving a state. Do state clean up jobs here */ 66 static void otg_leave_state(struct otg_fsm *fsm, enum usb_otg_state old_state) 67 { 68 switch (old_state) { 69 case OTG_STATE_B_IDLE: 70 otg_del_timer(fsm, B_SE0_SRP); 71 fsm->b_se0_srp = 0; 72 fsm->adp_sns = 0; 73 fsm->adp_prb = 0; 74 break; 75 case OTG_STATE_B_SRP_INIT: 76 fsm->data_pulse = 0; 77 fsm->b_srp_done = 0; 78 break; 79 case OTG_STATE_B_PERIPHERAL: 80 if (fsm->otg->gadget) 81 fsm->otg->gadget->host_request_flag = 0; 82 break; 83 case OTG_STATE_B_WAIT_ACON: 84 otg_del_timer(fsm, B_ASE0_BRST); 85 fsm->b_ase0_brst_tmout = 0; 86 break; 87 case OTG_STATE_B_HOST: 88 break; 89 case OTG_STATE_A_IDLE: 90 fsm->adp_prb = 0; 91 break; 92 case OTG_STATE_A_WAIT_VRISE: 93 otg_del_timer(fsm, A_WAIT_VRISE); 94 fsm->a_wait_vrise_tmout = 0; 95 break; 96 case OTG_STATE_A_WAIT_BCON: 97 otg_del_timer(fsm, A_WAIT_BCON); 98 fsm->a_wait_bcon_tmout = 0; 99 break; 100 case OTG_STATE_A_HOST: 101 otg_del_timer(fsm, A_WAIT_ENUM); 102 break; 103 case OTG_STATE_A_SUSPEND: 104 otg_del_timer(fsm, A_AIDL_BDIS); 105 fsm->a_aidl_bdis_tmout = 0; 106 fsm->a_suspend_req_inf = 0; 107 break; 108 case OTG_STATE_A_PERIPHERAL: 109 otg_del_timer(fsm, A_BIDL_ADIS); 110 fsm->a_bidl_adis_tmout = 0; 111 if (fsm->otg->gadget) 112 fsm->otg->gadget->host_request_flag = 0; 113 break; 114 case OTG_STATE_A_WAIT_VFALL: 115 otg_del_timer(fsm, A_WAIT_VFALL); 116 fsm->a_wait_vfall_tmout = 0; 117 otg_del_timer(fsm, A_WAIT_VRISE); 118 break; 119 case OTG_STATE_A_VBUS_ERR: 120 break; 121 default: 122 break; 123 } 124 } 125 126 static void otg_hnp_polling_work(struct work_struct *work) 127 { 128 struct otg_fsm *fsm = container_of(to_delayed_work(work), 129 struct otg_fsm, hnp_polling_work); 130 struct usb_device *udev; 131 enum usb_otg_state state = fsm->otg->state; 132 u8 flag; 133 int retval; 134 135 if (state != OTG_STATE_A_HOST && state != OTG_STATE_B_HOST) 136 return; 137 138 udev = usb_hub_find_child(fsm->otg->host->root_hub, 1); 139 if (!udev) { 140 dev_err(fsm->otg->host->controller, 141 "no usb dev connected, can't start HNP polling\n"); 142 return; 143 } 144 145 *fsm->host_req_flag = 0; 146 /* Get host request flag from connected USB device */ 147 retval = usb_control_msg(udev, 148 usb_rcvctrlpipe(udev, 0), 149 USB_REQ_GET_STATUS, 150 USB_DIR_IN | USB_RECIP_DEVICE, 151 0, 152 OTG_STS_SELECTOR, 153 fsm->host_req_flag, 154 1, 155 USB_CTRL_GET_TIMEOUT); 156 if (retval != 1) { 157 dev_err(&udev->dev, "Get one byte OTG status failed\n"); 158 return; 159 } 160 161 flag = *fsm->host_req_flag; 162 if (flag == 0) { 163 /* Continue HNP polling */ 164 schedule_delayed_work(&fsm->hnp_polling_work, 165 msecs_to_jiffies(T_HOST_REQ_POLL)); 166 return; 167 } else if (flag != HOST_REQUEST_FLAG) { 168 dev_err(&udev->dev, "host request flag %d is invalid\n", flag); 169 return; 170 } 171 172 /* Host request flag is set */ 173 if (state == OTG_STATE_A_HOST) { 174 /* Set b_hnp_enable */ 175 if (!fsm->otg->host->b_hnp_enable) { 176 retval = usb_control_msg(udev, 177 usb_sndctrlpipe(udev, 0), 178 USB_REQ_SET_FEATURE, 0, 179 USB_DEVICE_B_HNP_ENABLE, 180 0, NULL, 0, 181 USB_CTRL_SET_TIMEOUT); 182 if (retval >= 0) 183 fsm->otg->host->b_hnp_enable = 1; 184 } 185 fsm->a_bus_req = 0; 186 } else if (state == OTG_STATE_B_HOST) { 187 fsm->b_bus_req = 0; 188 } 189 190 otg_statemachine(fsm); 191 } 192 193 static void otg_start_hnp_polling(struct otg_fsm *fsm) 194 { 195 /* 196 * The memory of host_req_flag should be allocated by 197 * controller driver, otherwise, hnp polling is not started. 198 */ 199 if (!fsm->host_req_flag) 200 return; 201 202 INIT_DELAYED_WORK(&fsm->hnp_polling_work, otg_hnp_polling_work); 203 schedule_delayed_work(&fsm->hnp_polling_work, 204 msecs_to_jiffies(T_HOST_REQ_POLL)); 205 } 206 207 /* Called when entering a state */ 208 static int otg_set_state(struct otg_fsm *fsm, enum usb_otg_state new_state) 209 { 210 if (fsm->otg->state == new_state) 211 return 0; 212 VDBG("Set state: %s\n", usb_otg_state_string(new_state)); 213 otg_leave_state(fsm, fsm->otg->state); 214 switch (new_state) { 215 case OTG_STATE_B_IDLE: 216 otg_drv_vbus(fsm, 0); 217 otg_chrg_vbus(fsm, 0); 218 otg_loc_conn(fsm, 0); 219 otg_loc_sof(fsm, 0); 220 /* 221 * Driver is responsible for starting ADP probing 222 * if ADP sensing times out. 223 */ 224 otg_start_adp_sns(fsm); 225 otg_set_protocol(fsm, PROTO_UNDEF); 226 otg_add_timer(fsm, B_SE0_SRP); 227 break; 228 case OTG_STATE_B_SRP_INIT: 229 otg_start_pulse(fsm); 230 otg_loc_sof(fsm, 0); 231 otg_set_protocol(fsm, PROTO_UNDEF); 232 otg_add_timer(fsm, B_SRP_FAIL); 233 break; 234 case OTG_STATE_B_PERIPHERAL: 235 otg_chrg_vbus(fsm, 0); 236 otg_loc_sof(fsm, 0); 237 otg_set_protocol(fsm, PROTO_GADGET); 238 otg_loc_conn(fsm, 1); 239 break; 240 case OTG_STATE_B_WAIT_ACON: 241 otg_chrg_vbus(fsm, 0); 242 otg_loc_conn(fsm, 0); 243 otg_loc_sof(fsm, 0); 244 otg_set_protocol(fsm, PROTO_HOST); 245 otg_add_timer(fsm, B_ASE0_BRST); 246 fsm->a_bus_suspend = 0; 247 break; 248 case OTG_STATE_B_HOST: 249 otg_chrg_vbus(fsm, 0); 250 otg_loc_conn(fsm, 0); 251 otg_loc_sof(fsm, 1); 252 otg_set_protocol(fsm, PROTO_HOST); 253 usb_bus_start_enum(fsm->otg->host, 254 fsm->otg->host->otg_port); 255 otg_start_hnp_polling(fsm); 256 break; 257 case OTG_STATE_A_IDLE: 258 otg_drv_vbus(fsm, 0); 259 otg_chrg_vbus(fsm, 0); 260 otg_loc_conn(fsm, 0); 261 otg_loc_sof(fsm, 0); 262 otg_start_adp_prb(fsm); 263 otg_set_protocol(fsm, PROTO_HOST); 264 break; 265 case OTG_STATE_A_WAIT_VRISE: 266 otg_drv_vbus(fsm, 1); 267 otg_loc_conn(fsm, 0); 268 otg_loc_sof(fsm, 0); 269 otg_set_protocol(fsm, PROTO_HOST); 270 otg_add_timer(fsm, A_WAIT_VRISE); 271 break; 272 case OTG_STATE_A_WAIT_BCON: 273 otg_drv_vbus(fsm, 1); 274 otg_loc_conn(fsm, 0); 275 otg_loc_sof(fsm, 0); 276 otg_set_protocol(fsm, PROTO_HOST); 277 otg_add_timer(fsm, A_WAIT_BCON); 278 break; 279 case OTG_STATE_A_HOST: 280 otg_drv_vbus(fsm, 1); 281 otg_loc_conn(fsm, 0); 282 otg_loc_sof(fsm, 1); 283 otg_set_protocol(fsm, PROTO_HOST); 284 /* 285 * When HNP is triggered while a_bus_req = 0, a_host will 286 * suspend too fast to complete a_set_b_hnp_en 287 */ 288 if (!fsm->a_bus_req || fsm->a_suspend_req_inf) 289 otg_add_timer(fsm, A_WAIT_ENUM); 290 otg_start_hnp_polling(fsm); 291 break; 292 case OTG_STATE_A_SUSPEND: 293 otg_drv_vbus(fsm, 1); 294 otg_loc_conn(fsm, 0); 295 otg_loc_sof(fsm, 0); 296 otg_set_protocol(fsm, PROTO_HOST); 297 otg_add_timer(fsm, A_AIDL_BDIS); 298 299 break; 300 case OTG_STATE_A_PERIPHERAL: 301 otg_loc_sof(fsm, 0); 302 otg_set_protocol(fsm, PROTO_GADGET); 303 otg_drv_vbus(fsm, 1); 304 otg_loc_conn(fsm, 1); 305 otg_add_timer(fsm, A_BIDL_ADIS); 306 break; 307 case OTG_STATE_A_WAIT_VFALL: 308 otg_drv_vbus(fsm, 0); 309 otg_loc_conn(fsm, 0); 310 otg_loc_sof(fsm, 0); 311 otg_set_protocol(fsm, PROTO_HOST); 312 otg_add_timer(fsm, A_WAIT_VFALL); 313 break; 314 case OTG_STATE_A_VBUS_ERR: 315 otg_drv_vbus(fsm, 0); 316 otg_loc_conn(fsm, 0); 317 otg_loc_sof(fsm, 0); 318 otg_set_protocol(fsm, PROTO_UNDEF); 319 break; 320 default: 321 break; 322 } 323 324 fsm->otg->state = new_state; 325 fsm->state_changed = 1; 326 return 0; 327 } 328 329 /* State change judgement */ 330 int otg_statemachine(struct otg_fsm *fsm) 331 { 332 enum usb_otg_state state; 333 334 mutex_lock(&fsm->lock); 335 336 state = fsm->otg->state; 337 fsm->state_changed = 0; 338 /* State machine state change judgement */ 339 340 switch (state) { 341 case OTG_STATE_UNDEFINED: 342 VDBG("fsm->id = %d\n", fsm->id); 343 if (fsm->id) 344 otg_set_state(fsm, OTG_STATE_B_IDLE); 345 else 346 otg_set_state(fsm, OTG_STATE_A_IDLE); 347 break; 348 case OTG_STATE_B_IDLE: 349 if (!fsm->id) 350 otg_set_state(fsm, OTG_STATE_A_IDLE); 351 else if (fsm->b_sess_vld && fsm->otg->gadget) 352 otg_set_state(fsm, OTG_STATE_B_PERIPHERAL); 353 else if ((fsm->b_bus_req || fsm->adp_change || fsm->power_up) && 354 fsm->b_ssend_srp && fsm->b_se0_srp) 355 otg_set_state(fsm, OTG_STATE_B_SRP_INIT); 356 break; 357 case OTG_STATE_B_SRP_INIT: 358 if (!fsm->id || fsm->b_srp_done) 359 otg_set_state(fsm, OTG_STATE_B_IDLE); 360 break; 361 case OTG_STATE_B_PERIPHERAL: 362 if (!fsm->id || !fsm->b_sess_vld) 363 otg_set_state(fsm, OTG_STATE_B_IDLE); 364 else if (fsm->b_bus_req && fsm->otg-> 365 gadget->b_hnp_enable && fsm->a_bus_suspend) 366 otg_set_state(fsm, OTG_STATE_B_WAIT_ACON); 367 break; 368 case OTG_STATE_B_WAIT_ACON: 369 if (fsm->a_conn) 370 otg_set_state(fsm, OTG_STATE_B_HOST); 371 else if (!fsm->id || !fsm->b_sess_vld) 372 otg_set_state(fsm, OTG_STATE_B_IDLE); 373 else if (fsm->a_bus_resume || fsm->b_ase0_brst_tmout) { 374 fsm->b_ase0_brst_tmout = 0; 375 otg_set_state(fsm, OTG_STATE_B_PERIPHERAL); 376 } 377 break; 378 case OTG_STATE_B_HOST: 379 if (!fsm->id || !fsm->b_sess_vld) 380 otg_set_state(fsm, OTG_STATE_B_IDLE); 381 else if (!fsm->b_bus_req || !fsm->a_conn || fsm->test_device) 382 otg_set_state(fsm, OTG_STATE_B_PERIPHERAL); 383 break; 384 case OTG_STATE_A_IDLE: 385 if (fsm->id) 386 otg_set_state(fsm, OTG_STATE_B_IDLE); 387 else if (!fsm->a_bus_drop && (fsm->a_bus_req || 388 fsm->a_srp_det || fsm->adp_change || fsm->power_up)) 389 otg_set_state(fsm, OTG_STATE_A_WAIT_VRISE); 390 break; 391 case OTG_STATE_A_WAIT_VRISE: 392 if (fsm->a_vbus_vld) 393 otg_set_state(fsm, OTG_STATE_A_WAIT_BCON); 394 else if (fsm->id || fsm->a_bus_drop || 395 fsm->a_wait_vrise_tmout) 396 otg_set_state(fsm, OTG_STATE_A_WAIT_VFALL); 397 break; 398 case OTG_STATE_A_WAIT_BCON: 399 if (!fsm->a_vbus_vld) 400 otg_set_state(fsm, OTG_STATE_A_VBUS_ERR); 401 else if (fsm->b_conn) 402 otg_set_state(fsm, OTG_STATE_A_HOST); 403 else if (fsm->id || fsm->a_bus_drop || fsm->a_wait_bcon_tmout) 404 otg_set_state(fsm, OTG_STATE_A_WAIT_VFALL); 405 break; 406 case OTG_STATE_A_HOST: 407 if (fsm->id || fsm->a_bus_drop) 408 otg_set_state(fsm, OTG_STATE_A_WAIT_VFALL); 409 else if ((!fsm->a_bus_req || fsm->a_suspend_req_inf) && 410 fsm->otg->host->b_hnp_enable) 411 otg_set_state(fsm, OTG_STATE_A_SUSPEND); 412 else if (!fsm->b_conn) 413 otg_set_state(fsm, OTG_STATE_A_WAIT_BCON); 414 else if (!fsm->a_vbus_vld) 415 otg_set_state(fsm, OTG_STATE_A_VBUS_ERR); 416 break; 417 case OTG_STATE_A_SUSPEND: 418 if (!fsm->b_conn && fsm->otg->host->b_hnp_enable) 419 otg_set_state(fsm, OTG_STATE_A_PERIPHERAL); 420 else if (!fsm->b_conn && !fsm->otg->host->b_hnp_enable) 421 otg_set_state(fsm, OTG_STATE_A_WAIT_BCON); 422 else if (fsm->a_bus_req || fsm->b_bus_resume) 423 otg_set_state(fsm, OTG_STATE_A_HOST); 424 else if (fsm->id || fsm->a_bus_drop || fsm->a_aidl_bdis_tmout) 425 otg_set_state(fsm, OTG_STATE_A_WAIT_VFALL); 426 else if (!fsm->a_vbus_vld) 427 otg_set_state(fsm, OTG_STATE_A_VBUS_ERR); 428 break; 429 case OTG_STATE_A_PERIPHERAL: 430 if (fsm->id || fsm->a_bus_drop) 431 otg_set_state(fsm, OTG_STATE_A_WAIT_VFALL); 432 else if (fsm->a_bidl_adis_tmout || fsm->b_bus_suspend) 433 otg_set_state(fsm, OTG_STATE_A_WAIT_BCON); 434 else if (!fsm->a_vbus_vld) 435 otg_set_state(fsm, OTG_STATE_A_VBUS_ERR); 436 break; 437 case OTG_STATE_A_WAIT_VFALL: 438 if (fsm->a_wait_vfall_tmout) 439 otg_set_state(fsm, OTG_STATE_A_IDLE); 440 break; 441 case OTG_STATE_A_VBUS_ERR: 442 if (fsm->id || fsm->a_bus_drop || fsm->a_clr_err) 443 otg_set_state(fsm, OTG_STATE_A_WAIT_VFALL); 444 break; 445 default: 446 break; 447 } 448 mutex_unlock(&fsm->lock); 449 450 VDBG("quit statemachine, changed = %d\n", fsm->state_changed); 451 return fsm->state_changed; 452 } 453 EXPORT_SYMBOL_GPL(otg_statemachine); 454 MODULE_LICENSE("GPL"); 455