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

   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 DEFINE_MUTEX(available_protocols_lock);
  30 static u64 available_protocols;
  31
  32 static int ir_raw_event_thread(void *data)
  33 {
  34         struct ir_raw_event ev;
  35         struct ir_raw_handler *handler;
  36         struct ir_raw_event_ctrl *raw = (struct ir_raw_event_ctrl *)data;
  37
  38         while (!kthread_should_stop()) {
  39
  40                 spin_lock_irq(&raw->lock);
  41
  42                 if (!kfifo_len(&raw->kfifo)) {
  43                         set_current_state(TASK_INTERRUPTIBLE);
  44
  45                         if (kthread_should_stop())
  46                                 set_current_state(TASK_RUNNING);
  47
  48                         spin_unlock_irq(&raw->lock);
  49                         schedule();
  50                         continue;
  51                 }
  52
  53                 if(!kfifo_out(&raw->kfifo, &ev, 1))
  54                         dev_err(&raw->dev->dev, "IR event FIFO is empty!\n");
  55                 spin_unlock_irq(&raw->lock);
  56
  57                 mutex_lock(&ir_raw_handler_lock);
  58                 list_for_each_entry(handler, &ir_raw_handler_list, list)
  59                         if (raw->dev->enabled_protocols & handler->protocols ||
  60                             !handler->protocols)
  61                                 handler->decode(raw->dev, ev);
  62                 raw->prev_ev = ev;
  63                 mutex_unlock(&ir_raw_handler_lock);
  64         }
  65
  66         return 0;
  67 }
  68
  69 /**
  70  * ir_raw_event_store() - pass a pulse/space duration to the raw ir decoders
  71  * @dev:        the struct rc_dev device descriptor
  72  * @ev:         the struct ir_raw_event descriptor of the pulse/space
  73  *
  74  * This routine (which may be called from an interrupt context) stores a
  75  * pulse/space duration for the raw ir decoding state machines. Pulses are
  76  * signalled as positive values and spaces as negative values. A zero value
  77  * will reset the decoding state machines.
  78  */
  79 int ir_raw_event_store(struct rc_dev *dev, struct ir_raw_event *ev)
  80 {
  81         if (!dev->raw)
  82                 return -EINVAL;
  83
  84         IR_dprintk(2, "sample: (%05dus %s)\n",
  85                    TO_US(ev->duration), TO_STR(ev->pulse));
  86
  87         if (!kfifo_put(&dev->raw->kfifo, *ev)) {
  88                 dev_err(&dev->dev, "IR event FIFO is full!\n");
  89                 return -ENOSPC;
  90         }
  91
  92         return 0;
  93 }
  94 EXPORT_SYMBOL_GPL(ir_raw_event_store);
  95
  96 /**
  97  * ir_raw_event_store_edge() - notify raw ir decoders of the start of a pulse/space
  98  * @dev:        the struct rc_dev device descriptor
  99  * @type:       the type of the event that has occurred
 100  *
 101  * This routine (which may be called from an interrupt context) is used to
 102  * store the beginning of an ir pulse or space (or the start/end of ir
 103  * reception) for the raw ir decoding state machines. This is used by
 104  * hardware which does not provide durations directly but only interrupts
 105  * (or similar events) on state change.
 106  */
 107 int ir_raw_event_store_edge(struct rc_dev *dev, enum raw_event_type type)
 108 {
 109         ktime_t                 now;
 110         s64                     delta; /* ns */
 111         DEFINE_IR_RAW_EVENT(ev);
 112         int                     rc = 0;
 113         int                     delay;
 114
 115         if (!dev->raw)
 116                 return -EINVAL;
 117
 118         now = ktime_get();
 119         delta = ktime_to_ns(ktime_sub(now, dev->raw->last_event));
 120         delay = MS_TO_NS(dev->input_dev->rep[REP_DELAY]);
 121
 122         /* Check for a long duration since last event or if we're
 123          * being called for the first time, note that delta can't
 124          * possibly be negative.
 125          */
 126         if (delta > delay || !dev->raw->last_type)
 127                 type |= IR_START_EVENT;
 128         else
 129                 ev.duration = delta;
 130
 131         if (type & IR_START_EVENT)
 132                 ir_raw_event_reset(dev);
 133         else if (dev->raw->last_type & IR_SPACE) {
 134                 ev.pulse = false;
 135                 rc = ir_raw_event_store(dev, &ev);
 136         } else if (dev->raw->last_type & IR_PULSE) {
 137                 ev.pulse = true;
 138                 rc = ir_raw_event_store(dev, &ev);
 139         } else
 140                 return 0;
 141
 142         dev->raw->last_event = now;
 143         dev->raw->last_type = type;
 144         return rc;
 145 }
 146 EXPORT_SYMBOL_GPL(ir_raw_event_store_edge);
 147
 148 /**
 149  * ir_raw_event_store_with_filter() - pass next pulse/space to decoders with some processing
 150  * @dev:        the struct rc_dev device descriptor
 151  * @type:       the type of the event that has occurred
 152  *
 153  * This routine (which may be called from an interrupt context) works
 154  * in similar manner to ir_raw_event_store_edge.
 155  * This routine is intended for devices with limited internal buffer
 156  * It automerges samples of same type, and handles timeouts. Returns non-zero
 157  * if the event was added, and zero if the event was ignored due to idle
 158  * processing.
 159  */
 160 int ir_raw_event_store_with_filter(struct rc_dev *dev, struct ir_raw_event *ev)
 161 {
 162         if (!dev->raw)
 163                 return -EINVAL;
 164
 165         /* Ignore spaces in idle mode */
 166         if (dev->idle && !ev->pulse)
 167                 return 0;
 168         else if (dev->idle)
 169                 ir_raw_event_set_idle(dev, false);
 170
 171         if (!dev->raw->this_ev.duration)
 172                 dev->raw->this_ev = *ev;
 173         else if (ev->pulse == dev->raw->this_ev.pulse)
 174                 dev->raw->this_ev.duration += ev->duration;
 175         else {
 176                 ir_raw_event_store(dev, &dev->raw->this_ev);
 177                 dev->raw->this_ev = *ev;
 178         }
 179
 180         /* Enter idle mode if nessesary */
 181         if (!ev->pulse && dev->timeout &&
 182             dev->raw->this_ev.duration >= dev->timeout)
 183                 ir_raw_event_set_idle(dev, true);
 184
 185         return 1;
 186 }
 187 EXPORT_SYMBOL_GPL(ir_raw_event_store_with_filter);
 188
 189 /**
 190  * ir_raw_event_set_idle() - provide hint to rc-core when the device is idle or not
 191  * @dev:        the struct rc_dev device descriptor
 192  * @idle:       whether the device is idle or not
 193  */
 194 void ir_raw_event_set_idle(struct rc_dev *dev, bool idle)
 195 {
 196         if (!dev->raw)
 197                 return;
 198
 199         IR_dprintk(2, "%s idle mode\n", idle ? "enter" : "leave");
 200
 201         if (idle) {
 202                 dev->raw->this_ev.timeout = true;
 203                 ir_raw_event_store(dev, &dev->raw->this_ev);
 204                 init_ir_raw_event(&dev->raw->this_ev);
 205         }
 206
 207         if (dev->s_idle)
 208                 dev->s_idle(dev, idle);
 209
 210         dev->idle = idle;
 211 }
 212 EXPORT_SYMBOL_GPL(ir_raw_event_set_idle);
 213
 214 /**
 215  * ir_raw_event_handle() - schedules the decoding of stored ir data
 216  * @dev:        the struct rc_dev device descriptor
 217  *
 218  * This routine will tell rc-core to start decoding stored ir data.
 219  */
 220 void ir_raw_event_handle(struct rc_dev *dev)
 221 {
 222         unsigned long flags;
 223
 224         if (!dev->raw)
 225                 return;
 226
 227         spin_lock_irqsave(&dev->raw->lock, flags);
 228         wake_up_process(dev->raw->thread);
 229         spin_unlock_irqrestore(&dev->raw->lock, flags);
 230 }
 231 EXPORT_SYMBOL_GPL(ir_raw_event_handle);
 232
 233 /* used internally by the sysfs interface */
 234 u64
 235 ir_raw_get_allowed_protocols(void)
 236 {
 237         u64 protocols;
 238         mutex_lock(&available_protocols_lock);
 239         protocols = available_protocols;
 240         mutex_unlock(&available_protocols_lock);
 241         return protocols;
 242 }
 243
 244 static int change_protocol(struct rc_dev *dev, u64 *rc_type)
 245 {
 246         /* the caller will update dev->enabled_protocols */
 247         return 0;
 248 }
 249
 250 static void ir_raw_disable_protocols(struct rc_dev *dev, u64 protocols)
 251 {
 252         mutex_lock(&dev->lock);
 253         dev->enabled_protocols &= ~protocols;
 254         dev->enabled_wakeup_protocols &= ~protocols;
 255         mutex_unlock(&dev->lock);
 256 }
 257
 258 /*
 259  * Used to (un)register raw event clients
 260  */
 261 int ir_raw_event_register(struct rc_dev *dev)
 262 {
 263         int rc;
 264         struct ir_raw_handler *handler;
 265
 266         if (!dev)
 267                 return -EINVAL;
 268
 269         dev->raw = kzalloc(sizeof(*dev->raw), GFP_KERNEL);
 270         if (!dev->raw)
 271                 return -ENOMEM;
 272
 273         dev->raw->dev = dev;
 274         dev->change_protocol = change_protocol;
 275         INIT_KFIFO(dev->raw->kfifo);
 276
 277         spin_lock_init(&dev->raw->lock);
 278         dev->raw->thread = kthread_run(ir_raw_event_thread, dev->raw,
 279                                        "rc%u", dev->minor);
 280
 281         if (IS_ERR(dev->raw->thread)) {
 282                 rc = PTR_ERR(dev->raw->thread);
 283                 goto out;
 284         }
 285
 286         mutex_lock(&ir_raw_handler_lock);
 287         list_add_tail(&dev->raw->list, &ir_raw_client_list);
 288         list_for_each_entry(handler, &ir_raw_handler_list, list)
 289                 if (handler->raw_register)
 290                         handler->raw_register(dev);
 291         mutex_unlock(&ir_raw_handler_lock);
 292
 293         return 0;
 294
 295 out:
 296         kfree(dev->raw);
 297         dev->raw = NULL;
 298         return rc;
 299 }
 300
 301 void ir_raw_event_unregister(struct rc_dev *dev)
 302 {
 303         struct ir_raw_handler *handler;
 304
 305         if (!dev || !dev->raw)
 306                 return;
 307
 308         kthread_stop(dev->raw->thread);
 309
 310         mutex_lock(&ir_raw_handler_lock);
 311         list_del(&dev->raw->list);
 312         list_for_each_entry(handler, &ir_raw_handler_list, list)
 313                 if (handler->raw_unregister)
 314                         handler->raw_unregister(dev);
 315         mutex_unlock(&ir_raw_handler_lock);
 316
 317         kfree(dev->raw);
 318         dev->raw = NULL;
 319 }
 320
 321 /*
 322  * Extension interface - used to register the IR decoders
 323  */
 324
 325 int ir_raw_handler_register(struct ir_raw_handler *ir_raw_handler)
 326 {
 327         struct ir_raw_event_ctrl *raw;
 328
 329         mutex_lock(&ir_raw_handler_lock);
 330         list_add_tail(&ir_raw_handler->list, &ir_raw_handler_list);
 331         if (ir_raw_handler->raw_register)
 332                 list_for_each_entry(raw, &ir_raw_client_list, list)
 333                         ir_raw_handler->raw_register(raw->dev);
 334         mutex_lock(&available_protocols_lock);
 335         available_protocols |= ir_raw_handler->protocols;
 336         mutex_unlock(&available_protocols_lock);
 337         mutex_unlock(&ir_raw_handler_lock);
 338
 339         return 0;
 340 }
 341 EXPORT_SYMBOL(ir_raw_handler_register);
 342
 343 void ir_raw_handler_unregister(struct ir_raw_handler *ir_raw_handler)
 344 {
 345         struct ir_raw_event_ctrl *raw;
 346         u64 protocols = ir_raw_handler->protocols;
 347
 348         mutex_lock(&ir_raw_handler_lock);
 349         list_del(&ir_raw_handler->list);
 350         list_for_each_entry(raw, &ir_raw_client_list, list) {
 351                 ir_raw_disable_protocols(raw->dev, protocols);
 352                 if (ir_raw_handler->raw_unregister)
 353                         ir_raw_handler->raw_unregister(raw->dev);
 354         }
 355         mutex_lock(&available_protocols_lock);
 356         available_protocols &= ~protocols;
 357         mutex_unlock(&available_protocols_lock);
 358         mutex_unlock(&ir_raw_handler_lock);
 359 }
 360 EXPORT_SYMBOL(ir_raw_handler_unregister);