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/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 /* Define the max number of pulse/space transitions to buffer */
  24 #define MAX_IR_EVENT_SIZE      512
  25
  26 /* Used to keep track of IR raw clients, protected by ir_raw_handler_lock */
  27 static LIST_HEAD(ir_raw_client_list);
  28
  29 /* Used to handle IR raw handler extensions */
  30 static DEFINE_MUTEX(ir_raw_handler_lock);
  31 static LIST_HEAD(ir_raw_handler_list);
  32 static u64 available_protocols;
  33
  34 #ifdef MODULE
  35 /* Used to load the decoders */
  36 static struct work_struct wq_load;
  37 #endif
  38
  39 static int ir_raw_event_thread(void *data)
  40 {
  41         struct ir_raw_event ev;
  42         struct ir_raw_handler *handler;
  43         struct ir_raw_event_ctrl *raw = (struct ir_raw_event_ctrl *)data;
  44         int retval;
  45
  46         while (!kthread_should_stop()) {
  47
  48                 spin_lock_irq(&raw->lock);
  49                 retval = kfifo_out(&raw->kfifo, &ev, sizeof(ev));
  50
  51                 if (!retval) {
  52                         set_current_state(TASK_INTERRUPTIBLE);
  53
  54                         if (kthread_should_stop())
  55                                 set_current_state(TASK_RUNNING);
  56
  57                         spin_unlock_irq(&raw->lock);
  58                         schedule();
  59                         continue;
  60                 }
  61
  62                 spin_unlock_irq(&raw->lock);
  63
  64
  65                 BUG_ON(retval != sizeof(ev));
  66
  67                 mutex_lock(&ir_raw_handler_lock);
  68                 list_for_each_entry(handler, &ir_raw_handler_list, list)
  69                         handler->decode(raw->dev, ev);
  70                 raw->prev_ev = ev;
  71                 mutex_unlock(&ir_raw_handler_lock);
  72         }
  73
  74         return 0;
  75 }
  76
  77 /**
  78  * ir_raw_event_store() - pass a pulse/space duration to the raw ir decoders
  79  * @dev:        the struct rc_dev device descriptor
  80  * @ev:         the struct ir_raw_event descriptor of the pulse/space
  81  *
  82  * This routine (which may be called from an interrupt context) stores a
  83  * pulse/space duration for the raw ir decoding state machines. Pulses are
  84  * signalled as positive values and spaces as negative values. A zero value
  85  * will reset the decoding state machines.
  86  */
  87 int ir_raw_event_store(struct rc_dev *dev, struct ir_raw_event *ev)
  88 {
  89         if (!dev->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(&dev->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  * @dev:        the struct rc_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 rc_dev *dev, enum raw_event_type type)
 114 {
 115         ktime_t                 now;
 116         s64                     delta; /* ns */
 117         DEFINE_IR_RAW_EVENT(ev);
 118         int                     rc = 0;
 119         int                     delay;
 120
 121         if (!dev->raw)
 122                 return -EINVAL;
 123
 124         now = ktime_get();
 125         delta = ktime_to_ns(ktime_sub(now, dev->raw->last_event));
 126         delay = MS_TO_NS(dev->input_dev->rep[REP_DELAY]);
 127
 128         /* Check for a long duration since last event or if we're
 129          * being called for the first time, note that delta can't
 130          * possibly be negative.
 131          */
 132         if (delta > delay || !dev->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(dev);
 139         else if (dev->raw->last_type & IR_SPACE) {
 140                 ev.pulse = false;
 141                 rc = ir_raw_event_store(dev, &ev);
 142         } else if (dev->raw->last_type & IR_PULSE) {
 143                 ev.pulse = true;
 144                 rc = ir_raw_event_store(dev, &ev);
 145         } else
 146                 return 0;
 147
 148         dev->raw->last_event = now;
 149         dev->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  * @dev:        the struct rc_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 similar 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 rc_dev *dev, struct ir_raw_event *ev)
 165 {
 166         if (!dev->raw)
 167                 return -EINVAL;
 168
 169         /* Ignore spaces in idle mode */
 170         if (dev->idle && !ev->pulse)
 171                 return 0;
 172         else if (dev->idle)
 173                 ir_raw_event_set_idle(dev, false);
 174
 175         if (!dev->raw->this_ev.duration)
 176                 dev->raw->this_ev = *ev;
 177         else if (ev->pulse == dev->raw->this_ev.pulse)
 178                 dev->raw->this_ev.duration += ev->duration;
 179         else {
 180                 ir_raw_event_store(dev, &dev->raw->this_ev);
 181                 dev->raw->this_ev = *ev;
 182         }
 183
 184         /* Enter idle mode if nessesary */
 185         if (!ev->pulse && dev->timeout &&
 186             dev->raw->this_ev.duration >= dev->timeout)
 187                 ir_raw_event_set_idle(dev, true);
 188
 189         return 0;
 190 }
 191 EXPORT_SYMBOL_GPL(ir_raw_event_store_with_filter);
 192
 193 /**
 194  * ir_raw_event_set_idle() - provide hint to rc-core when the device is idle or not
 195  * @dev:        the struct rc_dev device descriptor
 196  * @idle:       whether the device is idle or not
 197  */
 198 void ir_raw_event_set_idle(struct rc_dev *dev, bool idle)
 199 {
 200         if (!dev->raw)
 201                 return;
 202
 203         IR_dprintk(2, "%s idle mode\n", idle ? "enter" : "leave");
 204
 205         if (idle) {
 206                 dev->raw->this_ev.timeout = true;
 207                 ir_raw_event_store(dev, &dev->raw->this_ev);
 208                 init_ir_raw_event(&dev->raw->this_ev);
 209         }
 210
 211         if (dev->s_idle)
 212                 dev->s_idle(dev, idle);
 213
 214         dev->idle = idle;
 215 }
 216 EXPORT_SYMBOL_GPL(ir_raw_event_set_idle);
 217
 218 /**
 219  * ir_raw_event_handle() - schedules the decoding of stored ir data
 220  * @dev:        the struct rc_dev device descriptor
 221  *
 222  * This routine will tell rc-core to start decoding stored ir data.
 223  */
 224 void ir_raw_event_handle(struct rc_dev *dev)
 225 {
 226         unsigned long flags;
 227
 228         if (!dev->raw)
 229                 return;
 230
 231         spin_lock_irqsave(&dev->raw->lock, flags);
 232         wake_up_process(dev->raw->thread);
 233         spin_unlock_irqrestore(&dev->raw->lock, flags);
 234 }
 235 EXPORT_SYMBOL_GPL(ir_raw_event_handle);
 236
 237 /* used internally by the sysfs interface */
 238 u64
 239 ir_raw_get_allowed_protocols(void)
 240 {
 241         u64 protocols;
 242         mutex_lock(&ir_raw_handler_lock);
 243         protocols = available_protocols;
 244         mutex_unlock(&ir_raw_handler_lock);
 245         return protocols;
 246 }
 247
 248 /*
 249  * Used to (un)register raw event clients
 250  */
 251 int ir_raw_event_register(struct rc_dev *dev)
 252 {
 253         int rc;
 254         struct ir_raw_handler *handler;
 255
 256         if (!dev)
 257                 return -EINVAL;
 258
 259         dev->raw = kzalloc(sizeof(*dev->raw), GFP_KERNEL);
 260         if (!dev->raw)
 261                 return -ENOMEM;
 262
 263         dev->raw->dev = dev;
 264         dev->raw->enabled_protocols = ~0;
 265         rc = kfifo_alloc(&dev->raw->kfifo,
 266                          sizeof(struct ir_raw_event) * MAX_IR_EVENT_SIZE,
 267                          GFP_KERNEL);
 268         if (rc < 0)
 269                 goto out;
 270
 271         spin_lock_init(&dev->raw->lock);
 272         dev->raw->thread = kthread_run(ir_raw_event_thread, dev->raw,
 273                                        "rc%ld", dev->devno);
 274
 275         if (IS_ERR(dev->raw->thread)) {
 276                 rc = PTR_ERR(dev->raw->thread);
 277                 goto out;
 278         }
 279
 280         mutex_lock(&ir_raw_handler_lock);
 281         list_add_tail(&dev->raw->list, &ir_raw_client_list);
 282         list_for_each_entry(handler, &ir_raw_handler_list, list)
 283                 if (handler->raw_register)
 284                         handler->raw_register(dev);
 285         mutex_unlock(&ir_raw_handler_lock);
 286
 287         return 0;
 288
 289 out:
 290         kfree(dev->raw);
 291         dev->raw = NULL;
 292         return rc;
 293 }
 294
 295 void ir_raw_event_unregister(struct rc_dev *dev)
 296 {
 297         struct ir_raw_handler *handler;
 298
 299         if (!dev || !dev->raw)
 300                 return;
 301
 302         kthread_stop(dev->raw->thread);
 303
 304         mutex_lock(&ir_raw_handler_lock);
 305         list_del(&dev->raw->list);
 306         list_for_each_entry(handler, &ir_raw_handler_list, list)
 307                 if (handler->raw_unregister)
 308                         handler->raw_unregister(dev);
 309         mutex_unlock(&ir_raw_handler_lock);
 310
 311         kfifo_free(&dev->raw->kfifo);
 312         kfree(dev->raw);
 313         dev->raw = NULL;
 314 }
 315
 316 /*
 317  * Extension interface - used to register the IR decoders
 318  */
 319
 320 int ir_raw_handler_register(struct ir_raw_handler *ir_raw_handler)
 321 {
 322         struct ir_raw_event_ctrl *raw;
 323
 324         mutex_lock(&ir_raw_handler_lock);
 325         list_add_tail(&ir_raw_handler->list, &ir_raw_handler_list);
 326         if (ir_raw_handler->raw_register)
 327                 list_for_each_entry(raw, &ir_raw_client_list, list)
 328                         ir_raw_handler->raw_register(raw->dev);
 329         available_protocols |= ir_raw_handler->protocols;
 330         mutex_unlock(&ir_raw_handler_lock);
 331
 332         return 0;
 333 }
 334 EXPORT_SYMBOL(ir_raw_handler_register);
 335
 336 void ir_raw_handler_unregister(struct ir_raw_handler *ir_raw_handler)
 337 {
 338         struct ir_raw_event_ctrl *raw;
 339
 340         mutex_lock(&ir_raw_handler_lock);
 341         list_del(&ir_raw_handler->list);
 342         if (ir_raw_handler->raw_unregister)
 343                 list_for_each_entry(raw, &ir_raw_client_list, list)
 344                         ir_raw_handler->raw_unregister(raw->dev);
 345         available_protocols &= ~ir_raw_handler->protocols;
 346         mutex_unlock(&ir_raw_handler_lock);
 347 }
 348 EXPORT_SYMBOL(ir_raw_handler_unregister);
 349
 350 #ifdef MODULE
 351 static void init_decoders(struct work_struct *work)
 352 {
 353         /* Load the decoder modules */
 354
 355         load_nec_decode();
 356         load_rc5_decode();
 357         load_rc6_decode();
 358         load_jvc_decode();
 359         load_sony_decode();
 360         load_mce_kbd_decode();
 361         load_lirc_codec();
 362
 363         /* If needed, we may later add some init code. In this case,
 364            it is needed to change the CONFIG_MODULE test at rc-core.h
 365          */
 366 }
 367 #endif
 368
 369 void ir_raw_init(void)
 370 {
 371 #ifdef MODULE
 372         INIT_WORK(&wq_load, init_decoders);
 373         schedule_work(&wq_load);
 374 #endif
 375 }