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         DEFINE_IR_RAW_EVENT(ev);
 116         int                     rc = 0;
 117         int                     delay;
 118
 119         if (!dev->raw)
 120                 return -EINVAL;
 121
 122         now = ktime_get();
 123         delta = ktime_to_ns(ktime_sub(now, dev->raw->last_event));
 124         delay = MS_TO_NS(dev->input_dev->rep[REP_DELAY]);
 125
 126         /* Check for a long duration since last event or if we're
 127          * being called for the first time, note that delta can't
 128          * possibly be negative.
 129          */
 130         if (delta > delay || !dev->raw->last_type)
 131                 type |= IR_START_EVENT;
 132         else
 133                 ev.duration = delta;
 134
 135         if (type & IR_START_EVENT)
 136                 ir_raw_event_reset(dev);
 137         else if (dev->raw->last_type & IR_SPACE) {
 138                 ev.pulse = false;
 139                 rc = ir_raw_event_store(dev, &ev);
 140         } else if (dev->raw->last_type & IR_PULSE) {
 141                 ev.pulse = true;
 142                 rc = ir_raw_event_store(dev, &ev);
 143         } else
 144                 return 0;
 145
 146         dev->raw->last_event = now;
 147         dev->raw->last_type = type;
 148         return rc;
 149 }
 150 EXPORT_SYMBOL_GPL(ir_raw_event_store_edge);
 151
 152 /**
 153  * ir_raw_event_store_with_filter() - pass next pulse/space to decoders with some processing
 154  * @dev:        the struct rc_dev device descriptor
 155  * @type:       the type of the event that has occurred
 156  *
 157  * This routine (which may be called from an interrupt context) works
 158  * in similar manner to ir_raw_event_store_edge.
 159  * This routine is intended for devices with limited internal buffer
 160  * It automerges samples of same type, and handles timeouts
 161  */
 162 int ir_raw_event_store_with_filter(struct rc_dev *dev, struct ir_raw_event *ev)
 163 {
 164         if (!dev->raw)
 165                 return -EINVAL;
 166
 167         /* Ignore spaces in idle mode */
 168         if (dev->idle && !ev->pulse)
 169                 return 0;
 170         else if (dev->idle)
 171                 ir_raw_event_set_idle(dev, false);
 172
 173         if (!dev->raw->this_ev.duration)
 174                 dev->raw->this_ev = *ev;
 175         else if (ev->pulse == dev->raw->this_ev.pulse)
 176                 dev->raw->this_ev.duration += ev->duration;
 177         else {
 178                 ir_raw_event_store(dev, &dev->raw->this_ev);
 179                 dev->raw->this_ev = *ev;
 180         }
 181
 182         /* Enter idle mode if nessesary */
 183         if (!ev->pulse && dev->timeout &&
 184             dev->raw->this_ev.duration >= dev->timeout)
 185                 ir_raw_event_set_idle(dev, true);
 186
 187         return 0;
 188 }
 189 EXPORT_SYMBOL_GPL(ir_raw_event_store_with_filter);
 190
 191 /**
 192  * ir_raw_event_set_idle() - provide hint to rc-core when the device is idle or not
 193  * @dev:        the struct rc_dev device descriptor
 194  * @idle:       whether the device is idle or not
 195  */
 196 void ir_raw_event_set_idle(struct rc_dev *dev, bool idle)
 197 {
 198         if (!dev->raw)
 199                 return;
 200
 201         IR_dprintk(2, "%s idle mode\n", idle ? "enter" : "leave");
 202
 203         if (idle) {
 204                 dev->raw->this_ev.timeout = true;
 205                 ir_raw_event_store(dev, &dev->raw->this_ev);
 206                 init_ir_raw_event(&dev->raw->this_ev);
 207         }
 208
 209         if (dev->s_idle)
 210                 dev->s_idle(dev, idle);
 211
 212         dev->idle = idle;
 213 }
 214 EXPORT_SYMBOL_GPL(ir_raw_event_set_idle);
 215
 216 /**
 217  * ir_raw_event_handle() - schedules the decoding of stored ir data
 218  * @dev:        the struct rc_dev device descriptor
 219  *
 220  * This routine will tell rc-core to start decoding stored ir data.
 221  */
 222 void ir_raw_event_handle(struct rc_dev *dev)
 223 {
 224         unsigned long flags;
 225
 226         if (!dev->raw)
 227                 return;
 228
 229         spin_lock_irqsave(&dev->raw->lock, flags);
 230         wake_up_process(dev->raw->thread);
 231         spin_unlock_irqrestore(&dev->raw->lock, flags);
 232 }
 233 EXPORT_SYMBOL_GPL(ir_raw_event_handle);
 234
 235 /* used internally by the sysfs interface */
 236 u64
 237 ir_raw_get_allowed_protocols(void)
 238 {
 239         u64 protocols;
 240         mutex_lock(&ir_raw_handler_lock);
 241         protocols = available_protocols;
 242         mutex_unlock(&ir_raw_handler_lock);
 243         return protocols;
 244 }
 245
 246 /*
 247  * Used to (un)register raw event clients
 248  */
 249 int ir_raw_event_register(struct rc_dev *dev)
 250 {
 251         int rc;
 252         struct ir_raw_handler *handler;
 253
 254         if (!dev)
 255                 return -EINVAL;
 256
 257         dev->raw = kzalloc(sizeof(*dev->raw), GFP_KERNEL);
 258         if (!dev->raw)
 259                 return -ENOMEM;
 260
 261         dev->raw->dev = dev;
 262         dev->raw->enabled_protocols = ~0;
 263         rc = kfifo_alloc(&dev->raw->kfifo,
 264                          sizeof(struct ir_raw_event) * MAX_IR_EVENT_SIZE,
 265                          GFP_KERNEL);
 266         if (rc < 0)
 267                 goto out;
 268
 269         spin_lock_init(&dev->raw->lock);
 270         dev->raw->thread = kthread_run(ir_raw_event_thread, dev->raw,
 271                                        "rc%ld", dev->devno);
 272
 273         if (IS_ERR(dev->raw->thread)) {
 274                 rc = PTR_ERR(dev->raw->thread);
 275                 goto out;
 276         }
 277
 278         mutex_lock(&ir_raw_handler_lock);
 279         list_add_tail(&dev->raw->list, &ir_raw_client_list);
 280         list_for_each_entry(handler, &ir_raw_handler_list, list)
 281                 if (handler->raw_register)
 282                         handler->raw_register(dev);
 283         mutex_unlock(&ir_raw_handler_lock);
 284
 285         return 0;
 286
 287 out:
 288         kfree(dev->raw);
 289         dev->raw = NULL;
 290         return rc;
 291 }
 292
 293 void ir_raw_event_unregister(struct rc_dev *dev)
 294 {
 295         struct ir_raw_handler *handler;
 296
 297         if (!dev || !dev->raw)
 298                 return;
 299
 300         kthread_stop(dev->raw->thread);
 301
 302         mutex_lock(&ir_raw_handler_lock);
 303         list_del(&dev->raw->list);
 304         list_for_each_entry(handler, &ir_raw_handler_list, list)
 305                 if (handler->raw_unregister)
 306                         handler->raw_unregister(dev);
 307         mutex_unlock(&ir_raw_handler_lock);
 308
 309         kfifo_free(&dev->raw->kfifo);
 310         kfree(dev->raw);
 311         dev->raw = NULL;
 312 }
 313
 314 /*
 315  * Extension interface - used to register the IR decoders
 316  */
 317
 318 int ir_raw_handler_register(struct ir_raw_handler *ir_raw_handler)
 319 {
 320         struct ir_raw_event_ctrl *raw;
 321
 322         mutex_lock(&ir_raw_handler_lock);
 323         list_add_tail(&ir_raw_handler->list, &ir_raw_handler_list);
 324         if (ir_raw_handler->raw_register)
 325                 list_for_each_entry(raw, &ir_raw_client_list, list)
 326                         ir_raw_handler->raw_register(raw->dev);
 327         available_protocols |= ir_raw_handler->protocols;
 328         mutex_unlock(&ir_raw_handler_lock);
 329
 330         return 0;
 331 }
 332 EXPORT_SYMBOL(ir_raw_handler_register);
 333
 334 void ir_raw_handler_unregister(struct ir_raw_handler *ir_raw_handler)
 335 {
 336         struct ir_raw_event_ctrl *raw;
 337
 338         mutex_lock(&ir_raw_handler_lock);
 339         list_del(&ir_raw_handler->list);
 340         if (ir_raw_handler->raw_unregister)
 341                 list_for_each_entry(raw, &ir_raw_client_list, list)
 342                         ir_raw_handler->raw_unregister(raw->dev);
 343         available_protocols &= ~ir_raw_handler->protocols;
 344         mutex_unlock(&ir_raw_handler_lock);
 345 }
 346 EXPORT_SYMBOL(ir_raw_handler_unregister);
 347
 348 #ifdef MODULE
 349 static void init_decoders(struct work_struct *work)
 350 {
 351         /* Load the decoder modules */
 352
 353         load_nec_decode();
 354         load_rc5_decode();
 355         load_rc6_decode();
 356         load_jvc_decode();
 357         load_sony_decode();
 358         load_lirc_codec();
 359
 360         /* If needed, we may later add some init code. In this case,
 361            it is needed to change the CONFIG_MODULE test at rc-core.h
 362          */
 363 }
 364 #endif
 365
 366 void ir_raw_init(void)
 367 {
 368 #ifdef MODULE
 369         INIT_WORK(&wq_load, init_decoders);
 370         schedule_work(&wq_load);
 371 #endif
 372 }