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 /* Used to keep track of IR raw clients, protected by ir_raw_handler_lock */ 24 static LIST_HEAD(ir_raw_client_list); 25 26 /* Used to handle IR raw handler extensions */ 27 static DEFINE_MUTEX(ir_raw_handler_lock); 28 static LIST_HEAD(ir_raw_handler_list); 29 static DEFINE_MUTEX(available_protocols_lock); 30 static u64 available_protocols; 31 32 static int ir_raw_event_thread(void *data) 33 { 34 struct ir_raw_event ev; 35 struct ir_raw_handler *handler; 36 struct ir_raw_event_ctrl *raw = (struct ir_raw_event_ctrl *)data; 37 38 while (!kthread_should_stop()) { 39 40 spin_lock_irq(&raw->lock); 41 42 if (!kfifo_len(&raw->kfifo)) { 43 set_current_state(TASK_INTERRUPTIBLE); 44 45 if (kthread_should_stop()) 46 set_current_state(TASK_RUNNING); 47 48 spin_unlock_irq(&raw->lock); 49 schedule(); 50 continue; 51 } 52 53 if(!kfifo_out(&raw->kfifo, &ev, 1)) 54 dev_err(&raw->dev->dev, "IR event FIFO is empty!\n"); 55 spin_unlock_irq(&raw->lock); 56 57 mutex_lock(&ir_raw_handler_lock); 58 list_for_each_entry(handler, &ir_raw_handler_list, list) 59 if (raw->dev->enabled_protocols & handler->protocols || 60 !handler->protocols) 61 handler->decode(raw->dev, ev); 62 raw->prev_ev = ev; 63 mutex_unlock(&ir_raw_handler_lock); 64 } 65 66 return 0; 67 } 68 69 /** 70 * ir_raw_event_store() - pass a pulse/space duration to the raw ir decoders 71 * @dev: the struct rc_dev device descriptor 72 * @ev: the struct ir_raw_event descriptor of the pulse/space 73 * 74 * This routine (which may be called from an interrupt context) stores a 75 * pulse/space duration for the raw ir decoding state machines. Pulses are 76 * signalled as positive values and spaces as negative values. A zero value 77 * will reset the decoding state machines. 78 */ 79 int ir_raw_event_store(struct rc_dev *dev, struct ir_raw_event *ev) 80 { 81 if (!dev->raw) 82 return -EINVAL; 83 84 IR_dprintk(2, "sample: (%05dus %s)\n", 85 TO_US(ev->duration), TO_STR(ev->pulse)); 86 87 if (!kfifo_put(&dev->raw->kfifo, *ev)) { 88 dev_err(&dev->dev, "IR event FIFO is full!\n"); 89 return -ENOSPC; 90 } 91 92 return 0; 93 } 94 EXPORT_SYMBOL_GPL(ir_raw_event_store); 95 96 /** 97 * ir_raw_event_store_edge() - notify raw ir decoders of the start of a pulse/space 98 * @dev: the struct rc_dev device descriptor 99 * @type: the type of the event that has occurred 100 * 101 * This routine (which may be called from an interrupt context) is used to 102 * store the beginning of an ir pulse or space (or the start/end of ir 103 * reception) for the raw ir decoding state machines. This is used by 104 * hardware which does not provide durations directly but only interrupts 105 * (or similar events) on state change. 106 */ 107 int ir_raw_event_store_edge(struct rc_dev *dev, enum raw_event_type type) 108 { 109 ktime_t now; 110 s64 delta; /* ns */ 111 DEFINE_IR_RAW_EVENT(ev); 112 int rc = 0; 113 int delay; 114 115 if (!dev->raw) 116 return -EINVAL; 117 118 now = ktime_get(); 119 delta = ktime_to_ns(ktime_sub(now, dev->raw->last_event)); 120 delay = MS_TO_NS(dev->input_dev->rep[REP_DELAY]); 121 122 /* Check for a long duration since last event or if we're 123 * being called for the first time, note that delta can't 124 * possibly be negative. 125 */ 126 if (delta > delay || !dev->raw->last_type) 127 type |= IR_START_EVENT; 128 else 129 ev.duration = delta; 130 131 if (type & IR_START_EVENT) 132 ir_raw_event_reset(dev); 133 else if (dev->raw->last_type & IR_SPACE) { 134 ev.pulse = false; 135 rc = ir_raw_event_store(dev, &ev); 136 } else if (dev->raw->last_type & IR_PULSE) { 137 ev.pulse = true; 138 rc = ir_raw_event_store(dev, &ev); 139 } else 140 return 0; 141 142 dev->raw->last_event = now; 143 dev->raw->last_type = type; 144 return rc; 145 } 146 EXPORT_SYMBOL_GPL(ir_raw_event_store_edge); 147 148 /** 149 * ir_raw_event_store_with_filter() - pass next pulse/space to decoders with some processing 150 * @dev: the struct rc_dev device descriptor 151 * @type: the type of the event that has occurred 152 * 153 * This routine (which may be called from an interrupt context) works 154 * in similar manner to ir_raw_event_store_edge. 155 * This routine is intended for devices with limited internal buffer 156 * It automerges samples of same type, and handles timeouts. Returns non-zero 157 * if the event was added, and zero if the event was ignored due to idle 158 * processing. 159 */ 160 int ir_raw_event_store_with_filter(struct rc_dev *dev, struct ir_raw_event *ev) 161 { 162 if (!dev->raw) 163 return -EINVAL; 164 165 /* Ignore spaces in idle mode */ 166 if (dev->idle && !ev->pulse) 167 return 0; 168 else if (dev->idle) 169 ir_raw_event_set_idle(dev, false); 170 171 if (!dev->raw->this_ev.duration) 172 dev->raw->this_ev = *ev; 173 else if (ev->pulse == dev->raw->this_ev.pulse) 174 dev->raw->this_ev.duration += ev->duration; 175 else { 176 ir_raw_event_store(dev, &dev->raw->this_ev); 177 dev->raw->this_ev = *ev; 178 } 179 180 /* Enter idle mode if nessesary */ 181 if (!ev->pulse && dev->timeout && 182 dev->raw->this_ev.duration >= dev->timeout) 183 ir_raw_event_set_idle(dev, true); 184 185 return 1; 186 } 187 EXPORT_SYMBOL_GPL(ir_raw_event_store_with_filter); 188 189 /** 190 * ir_raw_event_set_idle() - provide hint to rc-core when the device is idle or not 191 * @dev: the struct rc_dev device descriptor 192 * @idle: whether the device is idle or not 193 */ 194 void ir_raw_event_set_idle(struct rc_dev *dev, bool idle) 195 { 196 if (!dev->raw) 197 return; 198 199 IR_dprintk(2, "%s idle mode\n", idle ? "enter" : "leave"); 200 201 if (idle) { 202 dev->raw->this_ev.timeout = true; 203 ir_raw_event_store(dev, &dev->raw->this_ev); 204 init_ir_raw_event(&dev->raw->this_ev); 205 } 206 207 if (dev->s_idle) 208 dev->s_idle(dev, idle); 209 210 dev->idle = idle; 211 } 212 EXPORT_SYMBOL_GPL(ir_raw_event_set_idle); 213 214 /** 215 * ir_raw_event_handle() - schedules the decoding of stored ir data 216 * @dev: the struct rc_dev device descriptor 217 * 218 * This routine will tell rc-core to start decoding stored ir data. 219 */ 220 void ir_raw_event_handle(struct rc_dev *dev) 221 { 222 unsigned long flags; 223 224 if (!dev->raw) 225 return; 226 227 spin_lock_irqsave(&dev->raw->lock, flags); 228 wake_up_process(dev->raw->thread); 229 spin_unlock_irqrestore(&dev->raw->lock, flags); 230 } 231 EXPORT_SYMBOL_GPL(ir_raw_event_handle); 232 233 /* used internally by the sysfs interface */ 234 u64 235 ir_raw_get_allowed_protocols(void) 236 { 237 u64 protocols; 238 mutex_lock(&available_protocols_lock); 239 protocols = available_protocols; 240 mutex_unlock(&available_protocols_lock); 241 return protocols; 242 } 243 244 static int change_protocol(struct rc_dev *dev, u64 *rc_type) 245 { 246 /* the caller will update dev->enabled_protocols */ 247 return 0; 248 } 249 250 static void ir_raw_disable_protocols(struct rc_dev *dev, u64 protocols) 251 { 252 mutex_lock(&dev->lock); 253 dev->enabled_protocols &= ~protocols; 254 dev->enabled_wakeup_protocols &= ~protocols; 255 mutex_unlock(&dev->lock); 256 } 257 258 /* 259 * Used to (un)register raw event clients 260 */ 261 int ir_raw_event_register(struct rc_dev *dev) 262 { 263 int rc; 264 struct ir_raw_handler *handler; 265 266 if (!dev) 267 return -EINVAL; 268 269 dev->raw = kzalloc(sizeof(*dev->raw), GFP_KERNEL); 270 if (!dev->raw) 271 return -ENOMEM; 272 273 dev->raw->dev = dev; 274 dev->change_protocol = change_protocol; 275 INIT_KFIFO(dev->raw->kfifo); 276 277 spin_lock_init(&dev->raw->lock); 278 dev->raw->thread = kthread_run(ir_raw_event_thread, dev->raw, 279 "rc%u", dev->minor); 280 281 if (IS_ERR(dev->raw->thread)) { 282 rc = PTR_ERR(dev->raw->thread); 283 goto out; 284 } 285 286 mutex_lock(&ir_raw_handler_lock); 287 list_add_tail(&dev->raw->list, &ir_raw_client_list); 288 list_for_each_entry(handler, &ir_raw_handler_list, list) 289 if (handler->raw_register) 290 handler->raw_register(dev); 291 mutex_unlock(&ir_raw_handler_lock); 292 293 return 0; 294 295 out: 296 kfree(dev->raw); 297 dev->raw = NULL; 298 return rc; 299 } 300 301 void ir_raw_event_unregister(struct rc_dev *dev) 302 { 303 struct ir_raw_handler *handler; 304 305 if (!dev || !dev->raw) 306 return; 307 308 kthread_stop(dev->raw->thread); 309 310 mutex_lock(&ir_raw_handler_lock); 311 list_del(&dev->raw->list); 312 list_for_each_entry(handler, &ir_raw_handler_list, list) 313 if (handler->raw_unregister) 314 handler->raw_unregister(dev); 315 mutex_unlock(&ir_raw_handler_lock); 316 317 kfree(dev->raw); 318 dev->raw = NULL; 319 } 320 321 /* 322 * Extension interface - used to register the IR decoders 323 */ 324 325 int ir_raw_handler_register(struct ir_raw_handler *ir_raw_handler) 326 { 327 struct ir_raw_event_ctrl *raw; 328 329 mutex_lock(&ir_raw_handler_lock); 330 list_add_tail(&ir_raw_handler->list, &ir_raw_handler_list); 331 if (ir_raw_handler->raw_register) 332 list_for_each_entry(raw, &ir_raw_client_list, list) 333 ir_raw_handler->raw_register(raw->dev); 334 mutex_lock(&available_protocols_lock); 335 available_protocols |= ir_raw_handler->protocols; 336 mutex_unlock(&available_protocols_lock); 337 mutex_unlock(&ir_raw_handler_lock); 338 339 return 0; 340 } 341 EXPORT_SYMBOL(ir_raw_handler_register); 342 343 void ir_raw_handler_unregister(struct ir_raw_handler *ir_raw_handler) 344 { 345 struct ir_raw_event_ctrl *raw; 346 u64 protocols = ir_raw_handler->protocols; 347 348 mutex_lock(&ir_raw_handler_lock); 349 list_del(&ir_raw_handler->list); 350 list_for_each_entry(raw, &ir_raw_client_list, list) { 351 ir_raw_disable_protocols(raw->dev, protocols); 352 if (ir_raw_handler->raw_unregister) 353 ir_raw_handler->raw_unregister(raw->dev); 354 } 355 mutex_lock(&available_protocols_lock); 356 available_protocols &= ~protocols; 357 mutex_unlock(&available_protocols_lock); 358 mutex_unlock(&ir_raw_handler_lock); 359 } 360 EXPORT_SYMBOL(ir_raw_handler_unregister); 361