drivers/media/rc/ir-raw.c

   1 /* ir-raw.c - handle IR pulse/space events
   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 "rc-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->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  * @dev:        the struct rc_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 rc_dev *dev, struct ir_raw_event *ev)
  86 {
  87         if (!dev->raw)
  88                 return -EINVAL;
  89
  90         IR_dprintk(2, "sample: (%05dus %s)\n",
  91                    TO_US(ev->duration), TO_STR(ev->pulse));
  92
  93         if (kfifo_in(&dev->raw->kfifo, ev, sizeof(*ev)) != sizeof(*ev))
  94                 return -ENOMEM;
  95
  96         return 0;
  97 }
  98 EXPORT_SYMBOL_GPL(ir_raw_event_store);
  99
 100 /**
 101  * ir_raw_event_store_edge() - notify raw ir decoders of the start of a pulse/space
 102  * @dev:        the struct rc_dev device descriptor
 103  * @type:       the type of the event that has occurred
 104  *
 105  * This routine (which may be called from an interrupt context) is used to
 106  * store the beginning of an ir pulse or space (or the start/end of ir
 107  * reception) for the raw ir decoding state machines. This is used by
 108  * hardware which does not provide durations directly but only interrupts
 109  * (or similar events) on state change.
 110  */
 111 int ir_raw_event_store_edge(struct rc_dev *dev, enum raw_event_type type)
 112 {
 113         ktime_t                 now;
 114         s64                     delta; /* ns */
 115         struct ir_raw_event     ev;
 116         int                     rc = 0;
 117
 118         if (!dev->raw)
 119                 return -EINVAL;
 120
 121         now = ktime_get();
 122         delta = ktime_to_ns(ktime_sub(now, dev->raw->last_event));
 123
 124         /* Check for a long duration since last event or if we're
 125          * being called for the first time, note that delta can't
 126          * possibly be negative.
 127          */
 128         ev.duration = 0;
 129         if (delta > IR_MAX_DURATION || !dev->raw->last_type)
 130                 type |= IR_START_EVENT;
 131         else
 132                 ev.duration = delta;
 133
 134         if (type & IR_START_EVENT)
 135                 ir_raw_event_reset(dev);
 136         else if (dev->raw->last_type & IR_SPACE) {
 137                 ev.pulse = false;
 138                 rc = ir_raw_event_store(dev, &ev);
 139         } else if (dev->raw->last_type & IR_PULSE) {
 140                 ev.pulse = true;
 141                 rc = ir_raw_event_store(dev, &ev);
 142         } else
 143                 return 0;
 144
 145         dev->raw->last_event = now;
 146         dev->raw->last_type = type;
 147         return rc;
 148 }
 149 EXPORT_SYMBOL_GPL(ir_raw_event_store_edge);
 150
 151 /**
 152  * ir_raw_event_store_with_filter() - pass next pulse/space to decoders with some processing
 153  * @dev:        the struct rc_dev device descriptor
 154  * @type:       the type of the event that has occurred
 155  *
 156  * This routine (which may be called from an interrupt context) works
 157  * in similiar manner to ir_raw_event_store_edge.
 158  * This routine is intended for devices with limited internal buffer
 159  * It automerges samples of same type, and handles timeouts
 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 0;
 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 /*
 246  * Used to (un)register raw event clients
 247  */
 248 int ir_raw_event_register(struct rc_dev *dev)
 249 {
 250         int rc;
 251         struct ir_raw_handler *handler;
 252
 253         if (!dev)
 254                 return -EINVAL;
 255
 256         dev->raw = kzalloc(sizeof(*dev->raw), GFP_KERNEL);
 257         if (!dev->raw)
 258                 return -ENOMEM;
 259
 260         dev->raw->dev = dev;
 261         dev->raw->enabled_protocols = ~0;
 262         rc = kfifo_alloc(&dev->raw->kfifo,
 263                          sizeof(struct ir_raw_event) * MAX_IR_EVENT_SIZE,
 264                          GFP_KERNEL);
 265         if (rc < 0)
 266                 goto out;
 267
 268         spin_lock_init(&dev->raw->lock);
 269         dev->raw->thread = kthread_run(ir_raw_event_thread, dev->raw,
 270                                        "rc%ld", dev->devno);
 271
 272         if (IS_ERR(dev->raw->thread)) {
 273                 rc = PTR_ERR(dev->raw->thread);
 274                 goto out;
 275         }
 276
 277         mutex_lock(&ir_raw_handler_lock);
 278         list_add_tail(&dev->raw->list, &ir_raw_client_list);
 279         list_for_each_entry(handler, &ir_raw_handler_list, list)
 280                 if (handler->raw_register)
 281                         handler->raw_register(dev);
 282         mutex_unlock(&ir_raw_handler_lock);
 283
 284         return 0;
 285
 286 out:
 287         kfree(dev->raw);
 288         dev->raw = NULL;
 289         return rc;
 290 }
 291
 292 void ir_raw_event_unregister(struct rc_dev *dev)
 293 {
 294         struct ir_raw_handler *handler;
 295
 296         if (!dev || !dev->raw)
 297                 return;
 298
 299         kthread_stop(dev->raw->thread);
 300
 301         mutex_lock(&ir_raw_handler_lock);
 302         list_del(&dev->raw->list);
 303         list_for_each_entry(handler, &ir_raw_handler_list, list)
 304                 if (handler->raw_unregister)
 305                         handler->raw_unregister(dev);
 306         mutex_unlock(&ir_raw_handler_lock);
 307
 308         kfifo_free(&dev->raw->kfifo);
 309         kfree(dev->raw);
 310         dev->raw = NULL;
 311 }
 312
 313 /*
 314  * Extension interface - used to register the IR decoders
 315  */
 316
 317 int ir_raw_handler_register(struct ir_raw_handler *ir_raw_handler)
 318 {
 319         struct ir_raw_event_ctrl *raw;
 320
 321         mutex_lock(&ir_raw_handler_lock);
 322         list_add_tail(&ir_raw_handler->list, &ir_raw_handler_list);
 323         if (ir_raw_handler->raw_register)
 324                 list_for_each_entry(raw, &ir_raw_client_list, list)
 325                         ir_raw_handler->raw_register(raw->dev);
 326         available_protocols |= ir_raw_handler->protocols;
 327         mutex_unlock(&ir_raw_handler_lock);
 328
 329         return 0;
 330 }
 331 EXPORT_SYMBOL(ir_raw_handler_register);
 332
 333 void ir_raw_handler_unregister(struct ir_raw_handler *ir_raw_handler)
 334 {
 335         struct ir_raw_event_ctrl *raw;
 336
 337         mutex_lock(&ir_raw_handler_lock);
 338         list_del(&ir_raw_handler->list);
 339         if (ir_raw_handler->raw_unregister)
 340                 list_for_each_entry(raw, &ir_raw_client_list, list)
 341                         ir_raw_handler->raw_unregister(raw->dev);
 342         available_protocols &= ~ir_raw_handler->protocols;
 343         mutex_unlock(&ir_raw_handler_lock);
 344 }
 345 EXPORT_SYMBOL(ir_raw_handler_unregister);
 346
 347 #ifdef MODULE
 348 static void init_decoders(struct work_struct *work)
 349 {
 350         /* Load the decoder modules */
 351
 352         load_nec_decode();
 353         load_rc5_decode();
 354         load_rc6_decode();
 355         load_jvc_decode();
 356         load_sony_decode();
 357         load_lirc_codec();
 358
 359         /* If needed, we may later add some init code. In this case,
 360            it is needed to change the CONFIG_MODULE test at rc-core.h
 361          */
 362 }
 363 #endif
 364
 365 void ir_raw_init(void)
 366 {
 367 #ifdef MODULE
 368         INIT_WORK(&wq_load, init_decoders);
 369         schedule_work(&wq_load);
 370 #endif
 371 }