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/kernel.h> 25 #include <linux/types.h> 26 #include <linux/mutex.h> 27 #include <linux/delay.h> 28 #include <linux/usb.h> 29 #include <linux/usb/gadget.h> 30 #include <linux/usb/otg.h> 31 #include <linux/usb/otg-fsm.h> 32 33 /* Change USB protocol when there is a protocol change */ 34 static int otg_set_protocol(struct otg_fsm *fsm, int protocol) 35 { 36 int ret = 0; 37 38 if (fsm->protocol != protocol) { 39 VDBG("Changing role fsm->protocol= %d; new protocol= %d\n", 40 fsm->protocol, protocol); 41 /* stop old protocol */ 42 if (fsm->protocol == PROTO_HOST) 43 ret = otg_start_host(fsm, 0); 44 else if (fsm->protocol == PROTO_GADGET) 45 ret = otg_start_gadget(fsm, 0); 46 if (ret) 47 return ret; 48 49 /* start new protocol */ 50 if (protocol == PROTO_HOST) 51 ret = otg_start_host(fsm, 1); 52 else if (protocol == PROTO_GADGET) 53 ret = otg_start_gadget(fsm, 1); 54 if (ret) 55 return ret; 56 57 fsm->protocol = protocol; 58 return 0; 59 } 60 61 return 0; 62 } 63 64 static int state_changed; 65 66 /* Called when leaving a state. Do state clean up jobs here */ 67 static void otg_leave_state(struct otg_fsm *fsm, enum usb_otg_state old_state) 68 { 69 switch (old_state) { 70 case OTG_STATE_B_IDLE: 71 otg_del_timer(fsm, B_SE0_SRP); 72 fsm->b_se0_srp = 0; 73 fsm->adp_sns = 0; 74 fsm->adp_prb = 0; 75 break; 76 case OTG_STATE_B_SRP_INIT: 77 fsm->data_pulse = 0; 78 fsm->b_srp_done = 0; 79 break; 80 case OTG_STATE_B_PERIPHERAL: 81 break; 82 case OTG_STATE_B_WAIT_ACON: 83 otg_del_timer(fsm, B_ASE0_BRST); 84 fsm->b_ase0_brst_tmout = 0; 85 break; 86 case OTG_STATE_B_HOST: 87 break; 88 case OTG_STATE_A_IDLE: 89 fsm->adp_prb = 0; 90 break; 91 case OTG_STATE_A_WAIT_VRISE: 92 otg_del_timer(fsm, A_WAIT_VRISE); 93 fsm->a_wait_vrise_tmout = 0; 94 break; 95 case OTG_STATE_A_WAIT_BCON: 96 otg_del_timer(fsm, A_WAIT_BCON); 97 fsm->a_wait_bcon_tmout = 0; 98 break; 99 case OTG_STATE_A_HOST: 100 otg_del_timer(fsm, A_WAIT_ENUM); 101 break; 102 case OTG_STATE_A_SUSPEND: 103 otg_del_timer(fsm, A_AIDL_BDIS); 104 fsm->a_aidl_bdis_tmout = 0; 105 fsm->a_suspend_req_inf = 0; 106 break; 107 case OTG_STATE_A_PERIPHERAL: 108 otg_del_timer(fsm, A_BIDL_ADIS); 109 fsm->a_bidl_adis_tmout = 0; 110 break; 111 case OTG_STATE_A_WAIT_VFALL: 112 otg_del_timer(fsm, A_WAIT_VFALL); 113 fsm->a_wait_vfall_tmout = 0; 114 otg_del_timer(fsm, A_WAIT_VRISE); 115 break; 116 case OTG_STATE_A_VBUS_ERR: 117 break; 118 default: 119 break; 120 } 121 } 122 123 /* Called when entering a state */ 124 static int otg_set_state(struct otg_fsm *fsm, enum usb_otg_state new_state) 125 { 126 state_changed = 1; 127 if (fsm->otg->state == new_state) 128 return 0; 129 VDBG("Set state: %s\n", usb_otg_state_string(new_state)); 130 otg_leave_state(fsm, fsm->otg->state); 131 switch (new_state) { 132 case OTG_STATE_B_IDLE: 133 otg_drv_vbus(fsm, 0); 134 otg_chrg_vbus(fsm, 0); 135 otg_loc_conn(fsm, 0); 136 otg_loc_sof(fsm, 0); 137 /* 138 * Driver is responsible for starting ADP probing 139 * if ADP sensing times out. 140 */ 141 otg_start_adp_sns(fsm); 142 otg_set_protocol(fsm, PROTO_UNDEF); 143 otg_add_timer(fsm, B_SE0_SRP); 144 break; 145 case OTG_STATE_B_SRP_INIT: 146 otg_start_pulse(fsm); 147 otg_loc_sof(fsm, 0); 148 otg_set_protocol(fsm, PROTO_UNDEF); 149 otg_add_timer(fsm, B_SRP_FAIL); 150 break; 151 case OTG_STATE_B_PERIPHERAL: 152 otg_chrg_vbus(fsm, 0); 153 otg_loc_sof(fsm, 0); 154 otg_set_protocol(fsm, PROTO_GADGET); 155 otg_loc_conn(fsm, 1); 156 break; 157 case OTG_STATE_B_WAIT_ACON: 158 otg_chrg_vbus(fsm, 0); 159 otg_loc_conn(fsm, 0); 160 otg_loc_sof(fsm, 0); 161 otg_set_protocol(fsm, PROTO_HOST); 162 otg_add_timer(fsm, B_ASE0_BRST); 163 fsm->a_bus_suspend = 0; 164 break; 165 case OTG_STATE_B_HOST: 166 otg_chrg_vbus(fsm, 0); 167 otg_loc_conn(fsm, 0); 168 otg_loc_sof(fsm, 1); 169 otg_set_protocol(fsm, PROTO_HOST); 170 usb_bus_start_enum(fsm->otg->host, 171 fsm->otg->host->otg_port); 172 break; 173 case OTG_STATE_A_IDLE: 174 otg_drv_vbus(fsm, 0); 175 otg_chrg_vbus(fsm, 0); 176 otg_loc_conn(fsm, 0); 177 otg_loc_sof(fsm, 0); 178 otg_start_adp_prb(fsm); 179 otg_set_protocol(fsm, PROTO_HOST); 180 break; 181 case OTG_STATE_A_WAIT_VRISE: 182 otg_drv_vbus(fsm, 1); 183 otg_loc_conn(fsm, 0); 184 otg_loc_sof(fsm, 0); 185 otg_set_protocol(fsm, PROTO_HOST); 186 otg_add_timer(fsm, A_WAIT_VRISE); 187 break; 188 case OTG_STATE_A_WAIT_BCON: 189 otg_drv_vbus(fsm, 1); 190 otg_loc_conn(fsm, 0); 191 otg_loc_sof(fsm, 0); 192 otg_set_protocol(fsm, PROTO_HOST); 193 otg_add_timer(fsm, A_WAIT_BCON); 194 break; 195 case OTG_STATE_A_HOST: 196 otg_drv_vbus(fsm, 1); 197 otg_loc_conn(fsm, 0); 198 otg_loc_sof(fsm, 1); 199 otg_set_protocol(fsm, PROTO_HOST); 200 /* 201 * When HNP is triggered while a_bus_req = 0, a_host will 202 * suspend too fast to complete a_set_b_hnp_en 203 */ 204 if (!fsm->a_bus_req || fsm->a_suspend_req_inf) 205 otg_add_timer(fsm, A_WAIT_ENUM); 206 break; 207 case OTG_STATE_A_SUSPEND: 208 otg_drv_vbus(fsm, 1); 209 otg_loc_conn(fsm, 0); 210 otg_loc_sof(fsm, 0); 211 otg_set_protocol(fsm, PROTO_HOST); 212 otg_add_timer(fsm, A_AIDL_BDIS); 213 214 break; 215 case OTG_STATE_A_PERIPHERAL: 216 otg_loc_sof(fsm, 0); 217 otg_set_protocol(fsm, PROTO_GADGET); 218 otg_drv_vbus(fsm, 1); 219 otg_loc_conn(fsm, 1); 220 otg_add_timer(fsm, A_BIDL_ADIS); 221 break; 222 case OTG_STATE_A_WAIT_VFALL: 223 otg_drv_vbus(fsm, 0); 224 otg_loc_conn(fsm, 0); 225 otg_loc_sof(fsm, 0); 226 otg_set_protocol(fsm, PROTO_HOST); 227 otg_add_timer(fsm, A_WAIT_VFALL); 228 break; 229 case OTG_STATE_A_VBUS_ERR: 230 otg_drv_vbus(fsm, 0); 231 otg_loc_conn(fsm, 0); 232 otg_loc_sof(fsm, 0); 233 otg_set_protocol(fsm, PROTO_UNDEF); 234 break; 235 default: 236 break; 237 } 238 239 fsm->otg->state = new_state; 240 return 0; 241 } 242 243 /* State change judgement */ 244 int otg_statemachine(struct otg_fsm *fsm) 245 { 246 enum usb_otg_state state; 247 248 mutex_lock(&fsm->lock); 249 250 state = fsm->otg->state; 251 state_changed = 0; 252 /* State machine state change judgement */ 253 254 switch (state) { 255 case OTG_STATE_UNDEFINED: 256 VDBG("fsm->id = %d\n", fsm->id); 257 if (fsm->id) 258 otg_set_state(fsm, OTG_STATE_B_IDLE); 259 else 260 otg_set_state(fsm, OTG_STATE_A_IDLE); 261 break; 262 case OTG_STATE_B_IDLE: 263 if (!fsm->id) 264 otg_set_state(fsm, OTG_STATE_A_IDLE); 265 else if (fsm->b_sess_vld && fsm->otg->gadget) 266 otg_set_state(fsm, OTG_STATE_B_PERIPHERAL); 267 else if ((fsm->b_bus_req || fsm->adp_change || fsm->power_up) && 268 fsm->b_ssend_srp && fsm->b_se0_srp) 269 otg_set_state(fsm, OTG_STATE_B_SRP_INIT); 270 break; 271 case OTG_STATE_B_SRP_INIT: 272 if (!fsm->id || fsm->b_srp_done) 273 otg_set_state(fsm, OTG_STATE_B_IDLE); 274 break; 275 case OTG_STATE_B_PERIPHERAL: 276 if (!fsm->id || !fsm->b_sess_vld) 277 otg_set_state(fsm, OTG_STATE_B_IDLE); 278 else if (fsm->b_bus_req && fsm->otg-> 279 gadget->b_hnp_enable && fsm->a_bus_suspend) 280 otg_set_state(fsm, OTG_STATE_B_WAIT_ACON); 281 break; 282 case OTG_STATE_B_WAIT_ACON: 283 if (fsm->a_conn) 284 otg_set_state(fsm, OTG_STATE_B_HOST); 285 else if (!fsm->id || !fsm->b_sess_vld) 286 otg_set_state(fsm, OTG_STATE_B_IDLE); 287 else if (fsm->a_bus_resume || fsm->b_ase0_brst_tmout) { 288 fsm->b_ase0_brst_tmout = 0; 289 otg_set_state(fsm, OTG_STATE_B_PERIPHERAL); 290 } 291 break; 292 case OTG_STATE_B_HOST: 293 if (!fsm->id || !fsm->b_sess_vld) 294 otg_set_state(fsm, OTG_STATE_B_IDLE); 295 else if (!fsm->b_bus_req || !fsm->a_conn || fsm->test_device) 296 otg_set_state(fsm, OTG_STATE_B_PERIPHERAL); 297 break; 298 case OTG_STATE_A_IDLE: 299 if (fsm->id) 300 otg_set_state(fsm, OTG_STATE_B_IDLE); 301 else if (!fsm->a_bus_drop && (fsm->a_bus_req || 302 fsm->a_srp_det || fsm->adp_change || fsm->power_up)) 303 otg_set_state(fsm, OTG_STATE_A_WAIT_VRISE); 304 break; 305 case OTG_STATE_A_WAIT_VRISE: 306 if (fsm->a_vbus_vld) 307 otg_set_state(fsm, OTG_STATE_A_WAIT_BCON); 308 else if (fsm->id || fsm->a_bus_drop || 309 fsm->a_wait_vrise_tmout) 310 otg_set_state(fsm, OTG_STATE_A_WAIT_VFALL); 311 break; 312 case OTG_STATE_A_WAIT_BCON: 313 if (!fsm->a_vbus_vld) 314 otg_set_state(fsm, OTG_STATE_A_VBUS_ERR); 315 else if (fsm->b_conn) 316 otg_set_state(fsm, OTG_STATE_A_HOST); 317 else if (fsm->id || fsm->a_bus_drop || fsm->a_wait_bcon_tmout) 318 otg_set_state(fsm, OTG_STATE_A_WAIT_VFALL); 319 break; 320 case OTG_STATE_A_HOST: 321 if (fsm->id || fsm->a_bus_drop) 322 otg_set_state(fsm, OTG_STATE_A_WAIT_VFALL); 323 else if ((!fsm->a_bus_req || fsm->a_suspend_req_inf) && 324 fsm->otg->host->b_hnp_enable) 325 otg_set_state(fsm, OTG_STATE_A_SUSPEND); 326 else if (!fsm->b_conn) 327 otg_set_state(fsm, OTG_STATE_A_WAIT_BCON); 328 else if (!fsm->a_vbus_vld) 329 otg_set_state(fsm, OTG_STATE_A_VBUS_ERR); 330 break; 331 case OTG_STATE_A_SUSPEND: 332 if (!fsm->b_conn && fsm->otg->host->b_hnp_enable) 333 otg_set_state(fsm, OTG_STATE_A_PERIPHERAL); 334 else if (!fsm->b_conn && !fsm->otg->host->b_hnp_enable) 335 otg_set_state(fsm, OTG_STATE_A_WAIT_BCON); 336 else if (fsm->a_bus_req || fsm->b_bus_resume) 337 otg_set_state(fsm, OTG_STATE_A_HOST); 338 else if (fsm->id || fsm->a_bus_drop || fsm->a_aidl_bdis_tmout) 339 otg_set_state(fsm, OTG_STATE_A_WAIT_VFALL); 340 else if (!fsm->a_vbus_vld) 341 otg_set_state(fsm, OTG_STATE_A_VBUS_ERR); 342 break; 343 case OTG_STATE_A_PERIPHERAL: 344 if (fsm->id || fsm->a_bus_drop) 345 otg_set_state(fsm, OTG_STATE_A_WAIT_VFALL); 346 else if (fsm->a_bidl_adis_tmout || fsm->b_bus_suspend) 347 otg_set_state(fsm, OTG_STATE_A_WAIT_BCON); 348 else if (!fsm->a_vbus_vld) 349 otg_set_state(fsm, OTG_STATE_A_VBUS_ERR); 350 break; 351 case OTG_STATE_A_WAIT_VFALL: 352 if (fsm->a_wait_vfall_tmout) 353 otg_set_state(fsm, OTG_STATE_A_IDLE); 354 break; 355 case OTG_STATE_A_VBUS_ERR: 356 if (fsm->id || fsm->a_bus_drop || fsm->a_clr_err) 357 otg_set_state(fsm, OTG_STATE_A_WAIT_VFALL); 358 break; 359 default: 360 break; 361 } 362 mutex_unlock(&fsm->lock); 363 364 VDBG("quit statemachine, changed = %d\n", state_changed); 365 return state_changed; 366 } 367 EXPORT_SYMBOL_GPL(otg_statemachine); 368