drivers/media/rc/ir-raw-event.c

   1 /* ir-raw-event.c - handle IR Pulse/Space event
   2  *
   3  * Copyright (C) 2010 by Mauro Carvalho Chehab <mchehab@redhat.com>
   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/kthread.h>
  16 #include <linux/mutex.h>
  17 #include <linux/sched.h>
  18 #include <linux/freezer.h>
  19 #include "ir-core-priv.h"
  20
  21 /* Define the max number of pulse/space transitions to buffer */
  22 #define MAX_IR_EVENT_SIZE      512
  23
  24 /* Used to keep track of IR raw clients, protected by ir_raw_handler_lock */
  25 static LIST_HEAD(ir_raw_client_list);
  26
  27 /* Used to handle IR raw handler extensions */
  28 static DEFINE_MUTEX(ir_raw_handler_lock);
  29 static LIST_HEAD(ir_raw_handler_list);
  30 static u64 available_protocols;
  31
  32 #ifdef MODULE
  33 /* Used to load the decoders */
  34 static struct work_struct wq_load;
  35 #endif
  36
  37 static int ir_raw_event_thread(void *data)
  38 {
  39         struct ir_raw_event ev;
  40         struct ir_raw_handler *handler;
  41         struct ir_raw_event_ctrl *raw = (struct ir_raw_event_ctrl *)data;
  42         int retval;
  43
  44         while (!kthread_should_stop()) {
  45
  46                 spin_lock_irq(&raw->lock);
  47                 retval = kfifo_out(&raw->kfifo, &ev, sizeof(ev));
  48
  49                 if (!retval) {
  50                         set_current_state(TASK_INTERRUPTIBLE);
  51
  52                         if (kthread_should_stop())
  53                                 set_current_state(TASK_RUNNING);
  54
  55                         spin_unlock_irq(&raw->lock);
  56                         schedule();
  57                         continue;
  58                 }
  59
  60                 spin_unlock_irq(&raw->lock);
  61
  62
  63                 BUG_ON(retval != sizeof(ev));
  64
  65                 mutex_lock(&ir_raw_handler_lock);
  66                 list_for_each_entry(handler, &ir_raw_handler_list, list)
  67                         handler->decode(raw->input_dev, ev);
  68                 raw->prev_ev = ev;
  69                 mutex_unlock(&ir_raw_handler_lock);
  70         }
  71
  72         return 0;
  73 }
  74
  75 /**
  76  * ir_raw_event_store() - pass a pulse/space duration to the raw ir decoders
  77  * @input_dev:  the struct input_dev device descriptor
  78  * @ev:         the struct ir_raw_event descriptor of the pulse/space
  79  *
  80  * This routine (which may be called from an interrupt context) stores a
  81  * pulse/space duration for the raw ir decoding state machines. Pulses are
  82  * signalled as positive values and spaces as negative values. A zero value
  83  * will reset the decoding state machines.
  84  */
  85 int ir_raw_event_store(struct input_dev *input_dev, struct ir_raw_event *ev)
  86 {
  87         struct ir_input_dev *ir = input_get_drvdata(input_dev);
  88
  89         if (!ir->raw)
  90                 return -EINVAL;
  91
  92         IR_dprintk(2, "sample: (%05dus %s)\n",
  93                 TO_US(ev->duration), TO_STR(ev->pulse));
  94
  95         if (kfifo_in(&ir->raw->kfifo, ev, sizeof(*ev)) != sizeof(*ev))
  96                 return -ENOMEM;
  97
  98         return 0;
  99 }
 100 EXPORT_SYMBOL_GPL(ir_raw_event_store);
 101
 102 /**
 103  * ir_raw_event_store_edge() - notify raw ir decoders of the start of a pulse/space
 104  * @input_dev:  the struct input_dev device descriptor
 105  * @type:       the type of the event that has occurred
 106  *
 107  * This routine (which may be called from an interrupt context) is used to
 108  * store the beginning of an ir pulse or space (or the start/end of ir
 109  * reception) for the raw ir decoding state machines. This is used by
 110  * hardware which does not provide durations directly but only interrupts
 111  * (or similar events) on state change.
 112  */
 113 int ir_raw_event_store_edge(struct input_dev *input_dev, enum raw_event_type type)
 114 {
 115         struct ir_input_dev     *ir = input_get_drvdata(input_dev);
 116         ktime_t                 now;
 117         s64                     delta; /* ns */
 118         struct ir_raw_event     ev;
 119         int                     rc = 0;
 120
 121         if (!ir->raw)
 122                 return -EINVAL;
 123
 124         now = ktime_get();
 125         delta = ktime_to_ns(ktime_sub(now, ir->raw->last_event));
 126
 127         /* Check for a long duration since last event or if we're
 128          * being called for the first time, note that delta can't
 129          * possibly be negative.
 130          */
 131         ev.duration = 0;
 132         if (delta > IR_MAX_DURATION || !ir->raw->last_type)
 133                 type |= IR_START_EVENT;
 134         else
 135                 ev.duration = delta;
 136
 137         if (type & IR_START_EVENT)
 138                 ir_raw_event_reset(input_dev);
 139         else if (ir->raw->last_type & IR_SPACE) {
 140                 ev.pulse = false;
 141                 rc = ir_raw_event_store(input_dev, &ev);
 142         } else if (ir->raw->last_type & IR_PULSE) {
 143                 ev.pulse = true;
 144                 rc = ir_raw_event_store(input_dev, &ev);
 145         } else
 146                 return 0;
 147
 148         ir->raw->last_event = now;
 149         ir->raw->last_type = type;
 150         return rc;
 151 }
 152 EXPORT_SYMBOL_GPL(ir_raw_event_store_edge);
 153
 154 /**
 155  * ir_raw_event_store_with_filter() - pass next pulse/space to decoders with some processing
 156  * @input_dev:  the struct input_dev device descriptor
 157  * @type:       the type of the event that has occurred
 158  *
 159  * This routine (which may be called from an interrupt context) works
 160  * in similiar manner to ir_raw_event_store_edge.
 161  * This routine is intended for devices with limited internal buffer
 162  * It automerges samples of same type, and handles timeouts
 163  */
 164 int ir_raw_event_store_with_filter(struct input_dev *input_dev,
 165                                                 struct ir_raw_event *ev)
 166 {
 167         struct ir_input_dev *ir = input_get_drvdata(input_dev);
 168         struct ir_raw_event_ctrl *raw = ir->raw;
 169
 170         if (!raw || !ir->props)
 171                 return -EINVAL;
 172
 173         /* Ignore spaces in idle mode */
 174         if (ir->idle && !ev->pulse)
 175                 return 0;
 176         else if (ir->idle)
 177                 ir_raw_event_set_idle(input_dev, false);
 178
 179         if (!raw->this_ev.duration) {
 180                 raw->this_ev = *ev;
 181         } else if (ev->pulse == raw->this_ev.pulse) {
 182                 raw->this_ev.duration += ev->duration;
 183         } else {
 184                 ir_raw_event_store(input_dev, &raw->this_ev);
 185                 raw->this_ev = *ev;
 186         }
 187
 188         /* Enter idle mode if nessesary */
 189         if (!ev->pulse && ir->props->timeout &&
 190                 raw->this_ev.duration >= ir->props->timeout) {
 191                 ir_raw_event_set_idle(input_dev, true);
 192         }
 193         return 0;
 194 }
 195 EXPORT_SYMBOL_GPL(ir_raw_event_store_with_filter);
 196
 197 /**
 198  * ir_raw_event_set_idle() - hint the ir core if device is receiving
 199  * IR data or not
 200  * @input_dev: the struct input_dev device descriptor
 201  * @idle: the hint value
 202  */
 203 void ir_raw_event_set_idle(struct input_dev *input_dev, bool idle)
 204 {
 205         struct ir_input_dev *ir = input_get_drvdata(input_dev);
 206         struct ir_raw_event_ctrl *raw = ir->raw;
 207
 208         if (!ir->props || !ir->raw)
 209                 return;
 210
 211         IR_dprintk(2, "%s idle mode\n", idle ? "enter" : "leave");
 212
 213         if (idle) {
 214                 raw->this_ev.timeout = true;
 215                 ir_raw_event_store(input_dev, &raw->this_ev);
 216                 init_ir_raw_event(&raw->this_ev);
 217         }
 218
 219         if (ir->props->s_idle)
 220                 ir->props->s_idle(ir->props->priv, idle);
 221         ir->idle = idle;
 222 }
 223 EXPORT_SYMBOL_GPL(ir_raw_event_set_idle);
 224
 225 /**
 226  * ir_raw_event_handle() - schedules the decoding of stored ir data
 227  * @input_dev:  the struct input_dev device descriptor
 228  *
 229  * This routine will signal the workqueue to start decoding stored ir data.
 230  */
 231 void ir_raw_event_handle(struct input_dev *input_dev)
 232 {
 233         struct ir_input_dev *ir = input_get_drvdata(input_dev);
 234         unsigned long flags;
 235
 236         if (!ir->raw)
 237                 return;
 238
 239         spin_lock_irqsave(&ir->raw->lock, flags);
 240         wake_up_process(ir->raw->thread);
 241         spin_unlock_irqrestore(&ir->raw->lock, flags);
 242 }
 243 EXPORT_SYMBOL_GPL(ir_raw_event_handle);
 244
 245 /* used internally by the sysfs interface */
 246 u64
 247 ir_raw_get_allowed_protocols()
 248 {
 249         u64 protocols;
 250         mutex_lock(&ir_raw_handler_lock);
 251         protocols = available_protocols;
 252         mutex_unlock(&ir_raw_handler_lock);
 253         return protocols;
 254 }
 255
 256 /*
 257  * Used to (un)register raw event clients
 258  */
 259 int ir_raw_event_register(struct input_dev *input_dev)
 260 {
 261         struct ir_input_dev *ir = input_get_drvdata(input_dev);
 262         int rc;
 263         struct ir_raw_handler *handler;
 264
 265         ir->raw = kzalloc(sizeof(*ir->raw), GFP_KERNEL);
 266         if (!ir->raw)
 267                 return -ENOMEM;
 268
 269         ir->raw->input_dev = input_dev;
 270
 271         ir->raw->enabled_protocols = ~0;
 272         rc = kfifo_alloc(&ir->raw->kfifo, sizeof(s64) * MAX_IR_EVENT_SIZE,
 273                          GFP_KERNEL);
 274         if (rc < 0) {
 275                 kfree(ir->raw);
 276                 ir->raw = NULL;
 277                 return rc;
 278         }
 279
 280         spin_lock_init(&ir->raw->lock);
 281         ir->raw->thread = kthread_run(ir_raw_event_thread, ir->raw,
 282                         "rc%u",  (unsigned int)ir->devno);
 283
 284         if (IS_ERR(ir->raw->thread)) {
 285                 int ret = PTR_ERR(ir->raw->thread);
 286
 287                 kfree(ir->raw);
 288                 ir->raw = NULL;
 289                 return ret;
 290         }
 291
 292         mutex_lock(&ir_raw_handler_lock);
 293         list_add_tail(&ir->raw->list, &ir_raw_client_list);
 294         list_for_each_entry(handler, &ir_raw_handler_list, list)
 295                 if (handler->raw_register)
 296                         handler->raw_register(ir->raw->input_dev);
 297         mutex_unlock(&ir_raw_handler_lock);
 298
 299         return 0;
 300 }
 301
 302 void ir_raw_event_unregister(struct input_dev *input_dev)
 303 {
 304         struct ir_input_dev *ir = input_get_drvdata(input_dev);
 305         struct ir_raw_handler *handler;
 306
 307         if (!ir->raw)
 308                 return;
 309
 310         kthread_stop(ir->raw->thread);
 311
 312         mutex_lock(&ir_raw_handler_lock);
 313         list_del(&ir->raw->list);
 314         list_for_each_entry(handler, &ir_raw_handler_list, list)
 315                 if (handler->raw_unregister)
 316                         handler->raw_unregister(ir->raw->input_dev);
 317         mutex_unlock(&ir_raw_handler_lock);
 318
 319         kfifo_free(&ir->raw->kfifo);
 320         kfree(ir->raw);
 321         ir->raw = NULL;
 322 }
 323
 324 /*
 325  * Extension interface - used to register the IR decoders
 326  */
 327
 328 int ir_raw_handler_register(struct ir_raw_handler *ir_raw_handler)
 329 {
 330         struct ir_raw_event_ctrl *raw;
 331
 332         mutex_lock(&ir_raw_handler_lock);
 333         list_add_tail(&ir_raw_handler->list, &ir_raw_handler_list);
 334         if (ir_raw_handler->raw_register)
 335                 list_for_each_entry(raw, &ir_raw_client_list, list)
 336                         ir_raw_handler->raw_register(raw->input_dev);
 337         available_protocols |= ir_raw_handler->protocols;
 338         mutex_unlock(&ir_raw_handler_lock);
 339
 340         return 0;
 341 }
 342 EXPORT_SYMBOL(ir_raw_handler_register);
 343
 344 void ir_raw_handler_unregister(struct ir_raw_handler *ir_raw_handler)
 345 {
 346         struct ir_raw_event_ctrl *raw;
 347
 348         mutex_lock(&ir_raw_handler_lock);
 349         list_del(&ir_raw_handler->list);
 350         if (ir_raw_handler->raw_unregister)
 351                 list_for_each_entry(raw, &ir_raw_client_list, list)
 352                         ir_raw_handler->raw_unregister(raw->input_dev);
 353         available_protocols &= ~ir_raw_handler->protocols;
 354         mutex_unlock(&ir_raw_handler_lock);
 355 }
 356 EXPORT_SYMBOL(ir_raw_handler_unregister);
 357
 358 #ifdef MODULE
 359 static void init_decoders(struct work_struct *work)
 360 {
 361         /* Load the decoder modules */
 362
 363         load_nec_decode();
 364         load_rc5_decode();
 365         load_rc6_decode();
 366         load_jvc_decode();
 367         load_sony_decode();
 368         load_lirc_codec();
 369
 370         /* If needed, we may later add some init code. In this case,
 371            it is needed to change the CONFIG_MODULE test at ir-core.h
 372          */
 373 }
 374 #endif
 375
 376 void ir_raw_init(void)
 377 {
 378 #ifdef MODULE
 379         INIT_WORK(&wq_load, init_decoders);
 380         schedule_work(&wq_load);
 381 #endif
 382 }