linux/drivers/media/rc/ir-raw.c
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   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 */
  27static LIST_HEAD(ir_raw_client_list);
  28
  29/* Used to handle IR raw handler extensions */
  30static DEFINE_MUTEX(ir_raw_handler_lock);
  31static LIST_HEAD(ir_raw_handler_list);
  32static u64 available_protocols;
  33
  34#ifdef MODULE
  35/* Used to load the decoders */
  36static struct work_struct wq_load;
  37#endif
  38
  39static 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 */
  87int 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}
 100EXPORT_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 */
 113int 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}
 152EXPORT_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 */
 164int 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}
 191EXPORT_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 */
 198void 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}
 216EXPORT_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 */
 224void 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}
 235EXPORT_SYMBOL_GPL(ir_raw_event_handle);
 236
 237/* used internally by the sysfs interface */
 238u64
 239ir_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 */
 251int 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
 289out:
 290        kfree(dev->raw);
 291        dev->raw = NULL;
 292        return rc;
 293}
 294
 295void 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
 320int 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}
 334EXPORT_SYMBOL(ir_raw_handler_register);
 335
 336void 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}
 348EXPORT_SYMBOL(ir_raw_handler_unregister);
 349
 350#ifdef MODULE
 351static 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_sanyo_decode();
 361        load_mce_kbd_decode();
 362        load_lirc_codec();
 363
 364        /* If needed, we may later add some init code. In this case,
 365           it is needed to change the CONFIG_MODULE test at rc-core.h
 366         */
 367}
 368#endif
 369
 370void ir_raw_init(void)
 371{
 372#ifdef MODULE
 373        INIT_WORK(&wq_load, init_decoders);
 374        schedule_work(&wq_load);
 375#endif
 376}
 377