1 /* rc-ir-raw.c - handle IR pulse/space events 2 * 3 * Copyright (C) 2010 by Mauro Carvalho Chehab 4 * 5 * This program is free software; you can redistribute it and/or modify 6 * it under the terms of the GNU General Public License as published by 7 * the Free Software Foundation version 2 of the License. 8 * 9 * This program is distributed in the hope that it will be useful, 10 * but WITHOUT ANY WARRANTY; without even the implied warranty of 11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 12 * GNU General Public License for more details. 13 */ 14 15 #include <linux/export.h> 16 #include <linux/kthread.h> 17 #include <linux/mutex.h> 18 #include <linux/kmod.h> 19 #include <linux/sched.h> 20 #include <linux/freezer.h> 21 #include "rc-core-priv.h" 22 23 /* Define the max number of pulse/space transitions to buffer */ 24 #define MAX_IR_EVENT_SIZE 512 25 26 /* Used to keep track of IR raw clients, protected by ir_raw_handler_lock */ 27 static LIST_HEAD(ir_raw_client_list); 28 29 /* Used to handle IR raw handler extensions */ 30 static DEFINE_MUTEX(ir_raw_handler_lock); 31 static LIST_HEAD(ir_raw_handler_list); 32 static u64 available_protocols; 33 34 static int ir_raw_event_thread(void *data) 35 { 36 struct ir_raw_event ev; 37 struct ir_raw_handler *handler; 38 struct ir_raw_event_ctrl *raw = (struct ir_raw_event_ctrl *)data; 39 int retval; 40 41 while (!kthread_should_stop()) { 42 43 spin_lock_irq(&raw->lock); 44 retval = kfifo_len(&raw->kfifo); 45 46 if (retval < sizeof(ev)) { 47 set_current_state(TASK_INTERRUPTIBLE); 48 49 if (kthread_should_stop()) 50 set_current_state(TASK_RUNNING); 51 52 spin_unlock_irq(&raw->lock); 53 schedule(); 54 continue; 55 } 56 57 retval = kfifo_out(&raw->kfifo, &ev, sizeof(ev)); 58 spin_unlock_irq(&raw->lock); 59 60 mutex_lock(&ir_raw_handler_lock); 61 list_for_each_entry(handler, &ir_raw_handler_list, list) 62 if (raw->dev->enabled_protocols & handler->protocols || 63 !handler->protocols) 64 handler->decode(raw->dev, ev); 65 raw->prev_ev = ev; 66 mutex_unlock(&ir_raw_handler_lock); 67 } 68 69 return 0; 70 } 71 72 /** 73 * ir_raw_event_store() - pass a pulse/space duration to the raw ir decoders 74 * @dev: the struct rc_dev device descriptor 75 * @ev: the struct ir_raw_event descriptor of the pulse/space 76 * 77 * This routine (which may be called from an interrupt context) stores a 78 * pulse/space duration for the raw ir decoding state machines. Pulses are 79 * signalled as positive values and spaces as negative values. A zero value 80 * will reset the decoding state machines. 81 */ 82 int ir_raw_event_store(struct rc_dev *dev, struct ir_raw_event *ev) 83 { 84 if (!dev->raw) 85 return -EINVAL; 86 87 IR_dprintk(2, "sample: (%05dus %s)\n", 88 TO_US(ev->duration), TO_STR(ev->pulse)); 89 90 if (kfifo_in(&dev->raw->kfifo, ev, sizeof(*ev)) != sizeof(*ev)) 91 return -ENOMEM; 92 93 return 0; 94 } 95 EXPORT_SYMBOL_GPL(ir_raw_event_store); 96 97 /** 98 * ir_raw_event_store_edge() - notify raw ir decoders of the start of a pulse/space 99 * @dev: the struct rc_dev device descriptor 100 * @type: the type of the event that has occurred 101 * 102 * This routine (which may be called from an interrupt context) is used to 103 * store the beginning of an ir pulse or space (or the start/end of ir 104 * reception) for the raw ir decoding state machines. This is used by 105 * hardware which does not provide durations directly but only interrupts 106 * (or similar events) on state change. 107 */ 108 int ir_raw_event_store_edge(struct rc_dev *dev, enum raw_event_type type) 109 { 110 ktime_t now; 111 s64 delta; /* ns */ 112 DEFINE_IR_RAW_EVENT(ev); 113 int rc = 0; 114 int delay; 115 116 if (!dev->raw) 117 return -EINVAL; 118 119 now = ktime_get(); 120 delta = ktime_to_ns(ktime_sub(now, dev->raw->last_event)); 121 delay = MS_TO_NS(dev->input_dev->rep[REP_DELAY]); 122 123 /* Check for a long duration since last event or if we're 124 * being called for the first time, note that delta can't 125 * possibly be negative. 126 */ 127 if (delta > delay || !dev->raw->last_type) 128 type |= IR_START_EVENT; 129 else 130 ev.duration = delta; 131 132 if (type & IR_START_EVENT) 133 ir_raw_event_reset(dev); 134 else if (dev->raw->last_type & IR_SPACE) { 135 ev.pulse = false; 136 rc = ir_raw_event_store(dev, &ev); 137 } else if (dev->raw->last_type & IR_PULSE) { 138 ev.pulse = true; 139 rc = ir_raw_event_store(dev, &ev); 140 } else 141 return 0; 142 143 dev->raw->last_event = now; 144 dev->raw->last_type = type; 145 return rc; 146 } 147 EXPORT_SYMBOL_GPL(ir_raw_event_store_edge); 148 149 /** 150 * ir_raw_event_store_with_filter() - pass next pulse/space to decoders with some processing 151 * @dev: the struct rc_dev device descriptor 152 * @type: the type of the event that has occurred 153 * 154 * This routine (which may be called from an interrupt context) works 155 * in similar manner to ir_raw_event_store_edge. 156 * This routine is intended for devices with limited internal buffer 157 * It automerges samples of same type, and handles timeouts. Returns non-zero 158 * if the event was added, and zero if the event was ignored due to idle 159 * processing. 160 */ 161 int ir_raw_event_store_with_filter(struct rc_dev *dev, struct ir_raw_event *ev) 162 { 163 if (!dev->raw) 164 return -EINVAL; 165 166 /* Ignore spaces in idle mode */ 167 if (dev->idle && !ev->pulse) 168 return 0; 169 else if (dev->idle) 170 ir_raw_event_set_idle(dev, false); 171 172 if (!dev->raw->this_ev.duration) 173 dev->raw->this_ev = *ev; 174 else if (ev->pulse == dev->raw->this_ev.pulse) 175 dev->raw->this_ev.duration += ev->duration; 176 else { 177 ir_raw_event_store(dev, &dev->raw->this_ev); 178 dev->raw->this_ev = *ev; 179 } 180 181 /* Enter idle mode if nessesary */ 182 if (!ev->pulse && dev->timeout && 183 dev->raw->this_ev.duration >= dev->timeout) 184 ir_raw_event_set_idle(dev, true); 185 186 return 1; 187 } 188 EXPORT_SYMBOL_GPL(ir_raw_event_store_with_filter); 189 190 /** 191 * ir_raw_event_set_idle() - provide hint to rc-core when the device is idle or not 192 * @dev: the struct rc_dev device descriptor 193 * @idle: whether the device is idle or not 194 */ 195 void ir_raw_event_set_idle(struct rc_dev *dev, bool idle) 196 { 197 if (!dev->raw) 198 return; 199 200 IR_dprintk(2, "%s idle mode\n", idle ? "enter" : "leave"); 201 202 if (idle) { 203 dev->raw->this_ev.timeout = true; 204 ir_raw_event_store(dev, &dev->raw->this_ev); 205 init_ir_raw_event(&dev->raw->this_ev); 206 } 207 208 if (dev->s_idle) 209 dev->s_idle(dev, idle); 210 211 dev->idle = idle; 212 } 213 EXPORT_SYMBOL_GPL(ir_raw_event_set_idle); 214 215 /** 216 * ir_raw_event_handle() - schedules the decoding of stored ir data 217 * @dev: the struct rc_dev device descriptor 218 * 219 * This routine will tell rc-core to start decoding stored ir data. 220 */ 221 void ir_raw_event_handle(struct rc_dev *dev) 222 { 223 unsigned long flags; 224 225 if (!dev->raw) 226 return; 227 228 spin_lock_irqsave(&dev->raw->lock, flags); 229 wake_up_process(dev->raw->thread); 230 spin_unlock_irqrestore(&dev->raw->lock, flags); 231 } 232 EXPORT_SYMBOL_GPL(ir_raw_event_handle); 233 234 /* used internally by the sysfs interface */ 235 u64 236 ir_raw_get_allowed_protocols(void) 237 { 238 u64 protocols; 239 mutex_lock(&ir_raw_handler_lock); 240 protocols = available_protocols; 241 mutex_unlock(&ir_raw_handler_lock); 242 return protocols; 243 } 244 245 static int change_protocol(struct rc_dev *dev, u64 *rc_type) 246 { 247 /* the caller will update dev->enabled_protocols */ 248 return 0; 249 } 250 251 static void ir_raw_disable_protocols(struct rc_dev *dev, u64 protocols) 252 { 253 mutex_lock(&dev->lock); 254 dev->enabled_protocols &= ~protocols; 255 dev->enabled_wakeup_protocols &= ~protocols; 256 mutex_unlock(&dev->lock); 257 } 258 259 /* 260 * Used to (un)register raw event clients 261 */ 262 int ir_raw_event_register(struct rc_dev *dev) 263 { 264 int rc; 265 struct ir_raw_handler *handler; 266 267 if (!dev) 268 return -EINVAL; 269 270 dev->raw = kzalloc(sizeof(*dev->raw), GFP_KERNEL); 271 if (!dev->raw) 272 return -ENOMEM; 273 274 dev->raw->dev = dev; 275 dev->change_protocol = change_protocol; 276 rc = kfifo_alloc(&dev->raw->kfifo, 277 sizeof(struct ir_raw_event) * MAX_IR_EVENT_SIZE, 278 GFP_KERNEL); 279 if (rc < 0) 280 goto out; 281 282 spin_lock_init(&dev->raw->lock); 283 dev->raw->thread = kthread_run(ir_raw_event_thread, dev->raw, 284 "rc%u", dev->minor); 285 286 if (IS_ERR(dev->raw->thread)) { 287 rc = PTR_ERR(dev->raw->thread); 288 goto out; 289 } 290 291 mutex_lock(&ir_raw_handler_lock); 292 list_add_tail(&dev->raw->list, &ir_raw_client_list); 293 list_for_each_entry(handler, &ir_raw_handler_list, list) 294 if (handler->raw_register) 295 handler->raw_register(dev); 296 mutex_unlock(&ir_raw_handler_lock); 297 298 return 0; 299 300 out: 301 kfree(dev->raw); 302 dev->raw = NULL; 303 return rc; 304 } 305 306 void ir_raw_event_unregister(struct rc_dev *dev) 307 { 308 struct ir_raw_handler *handler; 309 310 if (!dev || !dev->raw) 311 return; 312 313 kthread_stop(dev->raw->thread); 314 315 mutex_lock(&ir_raw_handler_lock); 316 list_del(&dev->raw->list); 317 list_for_each_entry(handler, &ir_raw_handler_list, list) 318 if (handler->raw_unregister) 319 handler->raw_unregister(dev); 320 mutex_unlock(&ir_raw_handler_lock); 321 322 kfifo_free(&dev->raw->kfifo); 323 kfree(dev->raw); 324 dev->raw = NULL; 325 } 326 327 /* 328 * Extension interface - used to register the IR decoders 329 */ 330 331 int ir_raw_handler_register(struct ir_raw_handler *ir_raw_handler) 332 { 333 struct ir_raw_event_ctrl *raw; 334 335 mutex_lock(&ir_raw_handler_lock); 336 list_add_tail(&ir_raw_handler->list, &ir_raw_handler_list); 337 if (ir_raw_handler->raw_register) 338 list_for_each_entry(raw, &ir_raw_client_list, list) 339 ir_raw_handler->raw_register(raw->dev); 340 available_protocols |= ir_raw_handler->protocols; 341 mutex_unlock(&ir_raw_handler_lock); 342 343 return 0; 344 } 345 EXPORT_SYMBOL(ir_raw_handler_register); 346 347 void ir_raw_handler_unregister(struct ir_raw_handler *ir_raw_handler) 348 { 349 struct ir_raw_event_ctrl *raw; 350 u64 protocols = ir_raw_handler->protocols; 351 352 mutex_lock(&ir_raw_handler_lock); 353 list_del(&ir_raw_handler->list); 354 list_for_each_entry(raw, &ir_raw_client_list, list) { 355 ir_raw_disable_protocols(raw->dev, protocols); 356 if (ir_raw_handler->raw_unregister) 357 ir_raw_handler->raw_unregister(raw->dev); 358 } 359 available_protocols &= ~protocols; 360 mutex_unlock(&ir_raw_handler_lock); 361 } 362 EXPORT_SYMBOL(ir_raw_handler_unregister); 363