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