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 #ifdef VERBOSE 35 #define VDBG(fmt, args...) pr_debug("[%s] " fmt, \ 36 __func__, ## args) 37 #else 38 #define VDBG(stuff...) do {} while (0) 39 #endif 40 41 /* Change USB protocol when there is a protocol change */ 42 static int otg_set_protocol(struct otg_fsm *fsm, int protocol) 43 { 44 int ret = 0; 45 46 if (fsm->protocol != protocol) { 47 VDBG("Changing role fsm->protocol= %d; new protocol= %d\n", 48 fsm->protocol, protocol); 49 /* stop old protocol */ 50 if (fsm->protocol == PROTO_HOST) 51 ret = otg_start_host(fsm, 0); 52 else if (fsm->protocol == PROTO_GADGET) 53 ret = otg_start_gadget(fsm, 0); 54 if (ret) 55 return ret; 56 57 /* start new protocol */ 58 if (protocol == PROTO_HOST) 59 ret = otg_start_host(fsm, 1); 60 else if (protocol == PROTO_GADGET) 61 ret = otg_start_gadget(fsm, 1); 62 if (ret) 63 return ret; 64 65 fsm->protocol = protocol; 66 return 0; 67 } 68 69 return 0; 70 } 71 72 /* Called when leaving a state. Do state clean up jobs here */ 73 static void otg_leave_state(struct otg_fsm *fsm, enum usb_otg_state old_state) 74 { 75 switch (old_state) { 76 case OTG_STATE_B_IDLE: 77 otg_del_timer(fsm, B_SE0_SRP); 78 fsm->b_se0_srp = 0; 79 fsm->adp_sns = 0; 80 fsm->adp_prb = 0; 81 break; 82 case OTG_STATE_B_SRP_INIT: 83 fsm->data_pulse = 0; 84 fsm->b_srp_done = 0; 85 break; 86 case OTG_STATE_B_PERIPHERAL: 87 if (fsm->otg->gadget) 88 fsm->otg->gadget->host_request_flag = 0; 89 break; 90 case OTG_STATE_B_WAIT_ACON: 91 otg_del_timer(fsm, B_ASE0_BRST); 92 fsm->b_ase0_brst_tmout = 0; 93 break; 94 case OTG_STATE_B_HOST: 95 break; 96 case OTG_STATE_A_IDLE: 97 fsm->adp_prb = 0; 98 break; 99 case OTG_STATE_A_WAIT_VRISE: 100 otg_del_timer(fsm, A_WAIT_VRISE); 101 fsm->a_wait_vrise_tmout = 0; 102 break; 103 case OTG_STATE_A_WAIT_BCON: 104 otg_del_timer(fsm, A_WAIT_BCON); 105 fsm->a_wait_bcon_tmout = 0; 106 break; 107 case OTG_STATE_A_HOST: 108 otg_del_timer(fsm, A_WAIT_ENUM); 109 break; 110 case OTG_STATE_A_SUSPEND: 111 otg_del_timer(fsm, A_AIDL_BDIS); 112 fsm->a_aidl_bdis_tmout = 0; 113 fsm->a_suspend_req_inf = 0; 114 break; 115 case OTG_STATE_A_PERIPHERAL: 116 otg_del_timer(fsm, A_BIDL_ADIS); 117 fsm->a_bidl_adis_tmout = 0; 118 if (fsm->otg->gadget) 119 fsm->otg->gadget->host_request_flag = 0; 120 break; 121 case OTG_STATE_A_WAIT_VFALL: 122 otg_del_timer(fsm, A_WAIT_VFALL); 123 fsm->a_wait_vfall_tmout = 0; 124 otg_del_timer(fsm, A_WAIT_VRISE); 125 break; 126 case OTG_STATE_A_VBUS_ERR: 127 break; 128 default: 129 break; 130 } 131 } 132 133 static void otg_hnp_polling_work(struct work_struct *work) 134 { 135 struct otg_fsm *fsm = container_of(to_delayed_work(work), 136 struct otg_fsm, hnp_polling_work); 137 struct usb_device *udev; 138 enum usb_otg_state state = fsm->otg->state; 139 u8 flag; 140 int retval; 141 142 if (state != OTG_STATE_A_HOST && state != OTG_STATE_B_HOST) 143 return; 144 145 udev = usb_hub_find_child(fsm->otg->host->root_hub, 1); 146 if (!udev) { 147 dev_err(fsm->otg->host->controller, 148 "no usb dev connected, can't start HNP polling\n"); 149 return; 150 } 151 152 *fsm->host_req_flag = 0; 153 /* Get host request flag from connected USB device */ 154 retval = usb_control_msg(udev, 155 usb_rcvctrlpipe(udev, 0), 156 USB_REQ_GET_STATUS, 157 USB_DIR_IN | USB_RECIP_DEVICE, 158 0, 159 OTG_STS_SELECTOR, 160 fsm->host_req_flag, 161 1, 162 USB_CTRL_GET_TIMEOUT); 163 if (retval != 1) { 164 dev_err(&udev->dev, "Get one byte OTG status failed\n"); 165 return; 166 } 167 168 flag = *fsm->host_req_flag; 169 if (flag == 0) { 170 /* Continue HNP polling */ 171 schedule_delayed_work(&fsm->hnp_polling_work, 172 msecs_to_jiffies(T_HOST_REQ_POLL)); 173 return; 174 } else if (flag != HOST_REQUEST_FLAG) { 175 dev_err(&udev->dev, "host request flag %d is invalid\n", flag); 176 return; 177 } 178 179 /* Host request flag is set */ 180 if (state == OTG_STATE_A_HOST) { 181 /* Set b_hnp_enable */ 182 if (!fsm->otg->host->b_hnp_enable) { 183 retval = usb_control_msg(udev, 184 usb_sndctrlpipe(udev, 0), 185 USB_REQ_SET_FEATURE, 0, 186 USB_DEVICE_B_HNP_ENABLE, 187 0, NULL, 0, 188 USB_CTRL_SET_TIMEOUT); 189 if (retval >= 0) 190 fsm->otg->host->b_hnp_enable = 1; 191 } 192 fsm->a_bus_req = 0; 193 } else if (state == OTG_STATE_B_HOST) { 194 fsm->b_bus_req = 0; 195 } 196 197 otg_statemachine(fsm); 198 } 199 200 static void otg_start_hnp_polling(struct otg_fsm *fsm) 201 { 202 /* 203 * The memory of host_req_flag should be allocated by 204 * controller driver, otherwise, hnp polling is not started. 205 */ 206 if (!fsm->host_req_flag) 207 return; 208 209 INIT_DELAYED_WORK(&fsm->hnp_polling_work, otg_hnp_polling_work); 210 schedule_delayed_work(&fsm->hnp_polling_work, 211 msecs_to_jiffies(T_HOST_REQ_POLL)); 212 } 213 214 /* Called when entering a state */ 215 static int otg_set_state(struct otg_fsm *fsm, enum usb_otg_state new_state) 216 { 217 if (fsm->otg->state == new_state) 218 return 0; 219 VDBG("Set state: %s\n", usb_otg_state_string(new_state)); 220 otg_leave_state(fsm, fsm->otg->state); 221 switch (new_state) { 222 case OTG_STATE_B_IDLE: 223 otg_drv_vbus(fsm, 0); 224 otg_chrg_vbus(fsm, 0); 225 otg_loc_conn(fsm, 0); 226 otg_loc_sof(fsm, 0); 227 /* 228 * Driver is responsible for starting ADP probing 229 * if ADP sensing times out. 230 */ 231 otg_start_adp_sns(fsm); 232 otg_set_protocol(fsm, PROTO_UNDEF); 233 otg_add_timer(fsm, B_SE0_SRP); 234 break; 235 case OTG_STATE_B_SRP_INIT: 236 otg_start_pulse(fsm); 237 otg_loc_sof(fsm, 0); 238 otg_set_protocol(fsm, PROTO_UNDEF); 239 otg_add_timer(fsm, B_SRP_FAIL); 240 break; 241 case OTG_STATE_B_PERIPHERAL: 242 otg_chrg_vbus(fsm, 0); 243 otg_loc_sof(fsm, 0); 244 otg_set_protocol(fsm, PROTO_GADGET); 245 otg_loc_conn(fsm, 1); 246 break; 247 case OTG_STATE_B_WAIT_ACON: 248 otg_chrg_vbus(fsm, 0); 249 otg_loc_conn(fsm, 0); 250 otg_loc_sof(fsm, 0); 251 otg_set_protocol(fsm, PROTO_HOST); 252 otg_add_timer(fsm, B_ASE0_BRST); 253 fsm->a_bus_suspend = 0; 254 break; 255 case OTG_STATE_B_HOST: 256 otg_chrg_vbus(fsm, 0); 257 otg_loc_conn(fsm, 0); 258 otg_loc_sof(fsm, 1); 259 otg_set_protocol(fsm, PROTO_HOST); 260 usb_bus_start_enum(fsm->otg->host, 261 fsm->otg->host->otg_port); 262 otg_start_hnp_polling(fsm); 263 break; 264 case OTG_STATE_A_IDLE: 265 otg_drv_vbus(fsm, 0); 266 otg_chrg_vbus(fsm, 0); 267 otg_loc_conn(fsm, 0); 268 otg_loc_sof(fsm, 0); 269 otg_start_adp_prb(fsm); 270 otg_set_protocol(fsm, PROTO_HOST); 271 break; 272 case OTG_STATE_A_WAIT_VRISE: 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_VRISE); 278 break; 279 case OTG_STATE_A_WAIT_BCON: 280 otg_drv_vbus(fsm, 1); 281 otg_loc_conn(fsm, 0); 282 otg_loc_sof(fsm, 0); 283 otg_set_protocol(fsm, PROTO_HOST); 284 otg_add_timer(fsm, A_WAIT_BCON); 285 break; 286 case OTG_STATE_A_HOST: 287 otg_drv_vbus(fsm, 1); 288 otg_loc_conn(fsm, 0); 289 otg_loc_sof(fsm, 1); 290 otg_set_protocol(fsm, PROTO_HOST); 291 /* 292 * When HNP is triggered while a_bus_req = 0, a_host will 293 * suspend too fast to complete a_set_b_hnp_en 294 */ 295 if (!fsm->a_bus_req || fsm->a_suspend_req_inf) 296 otg_add_timer(fsm, A_WAIT_ENUM); 297 otg_start_hnp_polling(fsm); 298 break; 299 case OTG_STATE_A_SUSPEND: 300 otg_drv_vbus(fsm, 1); 301 otg_loc_conn(fsm, 0); 302 otg_loc_sof(fsm, 0); 303 otg_set_protocol(fsm, PROTO_HOST); 304 otg_add_timer(fsm, A_AIDL_BDIS); 305 306 break; 307 case OTG_STATE_A_PERIPHERAL: 308 otg_loc_sof(fsm, 0); 309 otg_set_protocol(fsm, PROTO_GADGET); 310 otg_drv_vbus(fsm, 1); 311 otg_loc_conn(fsm, 1); 312 otg_add_timer(fsm, A_BIDL_ADIS); 313 break; 314 case OTG_STATE_A_WAIT_VFALL: 315 otg_drv_vbus(fsm, 0); 316 otg_loc_conn(fsm, 0); 317 otg_loc_sof(fsm, 0); 318 otg_set_protocol(fsm, PROTO_HOST); 319 otg_add_timer(fsm, A_WAIT_VFALL); 320 break; 321 case OTG_STATE_A_VBUS_ERR: 322 otg_drv_vbus(fsm, 0); 323 otg_loc_conn(fsm, 0); 324 otg_loc_sof(fsm, 0); 325 otg_set_protocol(fsm, PROTO_UNDEF); 326 break; 327 default: 328 break; 329 } 330 331 fsm->otg->state = new_state; 332 fsm->state_changed = 1; 333 return 0; 334 } 335 336 /* State change judgement */ 337 int otg_statemachine(struct otg_fsm *fsm) 338 { 339 enum usb_otg_state state; 340 341 mutex_lock(&fsm->lock); 342 343 state = fsm->otg->state; 344 fsm->state_changed = 0; 345 /* State machine state change judgement */ 346 347 switch (state) { 348 case OTG_STATE_UNDEFINED: 349 VDBG("fsm->id = %d\n", fsm->id); 350 if (fsm->id) 351 otg_set_state(fsm, OTG_STATE_B_IDLE); 352 else 353 otg_set_state(fsm, OTG_STATE_A_IDLE); 354 break; 355 case OTG_STATE_B_IDLE: 356 if (!fsm->id) 357 otg_set_state(fsm, OTG_STATE_A_IDLE); 358 else if (fsm->b_sess_vld && fsm->otg->gadget) 359 otg_set_state(fsm, OTG_STATE_B_PERIPHERAL); 360 else if ((fsm->b_bus_req || fsm->adp_change || fsm->power_up) && 361 fsm->b_ssend_srp && fsm->b_se0_srp) 362 otg_set_state(fsm, OTG_STATE_B_SRP_INIT); 363 break; 364 case OTG_STATE_B_SRP_INIT: 365 if (!fsm->id || fsm->b_srp_done) 366 otg_set_state(fsm, OTG_STATE_B_IDLE); 367 break; 368 case OTG_STATE_B_PERIPHERAL: 369 if (!fsm->id || !fsm->b_sess_vld) 370 otg_set_state(fsm, OTG_STATE_B_IDLE); 371 else if (fsm->b_bus_req && fsm->otg-> 372 gadget->b_hnp_enable && fsm->a_bus_suspend) 373 otg_set_state(fsm, OTG_STATE_B_WAIT_ACON); 374 break; 375 case OTG_STATE_B_WAIT_ACON: 376 if (fsm->a_conn) 377 otg_set_state(fsm, OTG_STATE_B_HOST); 378 else if (!fsm->id || !fsm->b_sess_vld) 379 otg_set_state(fsm, OTG_STATE_B_IDLE); 380 else if (fsm->a_bus_resume || fsm->b_ase0_brst_tmout) { 381 fsm->b_ase0_brst_tmout = 0; 382 otg_set_state(fsm, OTG_STATE_B_PERIPHERAL); 383 } 384 break; 385 case OTG_STATE_B_HOST: 386 if (!fsm->id || !fsm->b_sess_vld) 387 otg_set_state(fsm, OTG_STATE_B_IDLE); 388 else if (!fsm->b_bus_req || !fsm->a_conn || fsm->test_device) 389 otg_set_state(fsm, OTG_STATE_B_PERIPHERAL); 390 break; 391 case OTG_STATE_A_IDLE: 392 if (fsm->id) 393 otg_set_state(fsm, OTG_STATE_B_IDLE); 394 else if (!fsm->a_bus_drop && (fsm->a_bus_req || 395 fsm->a_srp_det || fsm->adp_change || fsm->power_up)) 396 otg_set_state(fsm, OTG_STATE_A_WAIT_VRISE); 397 break; 398 case OTG_STATE_A_WAIT_VRISE: 399 if (fsm->a_vbus_vld) 400 otg_set_state(fsm, OTG_STATE_A_WAIT_BCON); 401 else if (fsm->id || fsm->a_bus_drop || 402 fsm->a_wait_vrise_tmout) 403 otg_set_state(fsm, OTG_STATE_A_WAIT_VFALL); 404 break; 405 case OTG_STATE_A_WAIT_BCON: 406 if (!fsm->a_vbus_vld) 407 otg_set_state(fsm, OTG_STATE_A_VBUS_ERR); 408 else if (fsm->b_conn) 409 otg_set_state(fsm, OTG_STATE_A_HOST); 410 else if (fsm->id || fsm->a_bus_drop || fsm->a_wait_bcon_tmout) 411 otg_set_state(fsm, OTG_STATE_A_WAIT_VFALL); 412 break; 413 case OTG_STATE_A_HOST: 414 if (fsm->id || fsm->a_bus_drop) 415 otg_set_state(fsm, OTG_STATE_A_WAIT_VFALL); 416 else if ((!fsm->a_bus_req || fsm->a_suspend_req_inf) && 417 fsm->otg->host->b_hnp_enable) 418 otg_set_state(fsm, OTG_STATE_A_SUSPEND); 419 else if (!fsm->b_conn) 420 otg_set_state(fsm, OTG_STATE_A_WAIT_BCON); 421 else if (!fsm->a_vbus_vld) 422 otg_set_state(fsm, OTG_STATE_A_VBUS_ERR); 423 break; 424 case OTG_STATE_A_SUSPEND: 425 if (!fsm->b_conn && fsm->otg->host->b_hnp_enable) 426 otg_set_state(fsm, OTG_STATE_A_PERIPHERAL); 427 else if (!fsm->b_conn && !fsm->otg->host->b_hnp_enable) 428 otg_set_state(fsm, OTG_STATE_A_WAIT_BCON); 429 else if (fsm->a_bus_req || fsm->b_bus_resume) 430 otg_set_state(fsm, OTG_STATE_A_HOST); 431 else if (fsm->id || fsm->a_bus_drop || fsm->a_aidl_bdis_tmout) 432 otg_set_state(fsm, OTG_STATE_A_WAIT_VFALL); 433 else if (!fsm->a_vbus_vld) 434 otg_set_state(fsm, OTG_STATE_A_VBUS_ERR); 435 break; 436 case OTG_STATE_A_PERIPHERAL: 437 if (fsm->id || fsm->a_bus_drop) 438 otg_set_state(fsm, OTG_STATE_A_WAIT_VFALL); 439 else if (fsm->a_bidl_adis_tmout || fsm->b_bus_suspend) 440 otg_set_state(fsm, OTG_STATE_A_WAIT_BCON); 441 else if (!fsm->a_vbus_vld) 442 otg_set_state(fsm, OTG_STATE_A_VBUS_ERR); 443 break; 444 case OTG_STATE_A_WAIT_VFALL: 445 if (fsm->a_wait_vfall_tmout) 446 otg_set_state(fsm, OTG_STATE_A_IDLE); 447 break; 448 case OTG_STATE_A_VBUS_ERR: 449 if (fsm->id || fsm->a_bus_drop || fsm->a_clr_err) 450 otg_set_state(fsm, OTG_STATE_A_WAIT_VFALL); 451 break; 452 default: 453 break; 454 } 455 mutex_unlock(&fsm->lock); 456 457 VDBG("quit statemachine, changed = %d\n", fsm->state_changed); 458 return fsm->state_changed; 459 } 460 EXPORT_SYMBOL_GPL(otg_statemachine); 461 MODULE_LICENSE("GPL"); 462