linux/drivers/media/rc/rc-loopback.c
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   1/*
   2 * Loopback driver for rc-core,
   3 *
   4 * Copyright (c) 2010 David Härdeman <david@hardeman.nu>
   5 *
   6 * This driver receives TX data and passes it back as RX data,
   7 * which is useful for (scripted) debugging of rc-core without
   8 * having to use actual hardware.
   9 *
  10 * This program is free software; you can redistribute it and/or modify
  11 * it under the terms of the GNU General Public License as published by
  12 * the Free Software Foundation; either version 2 of the License, or
  13 * (at your option) any later version.
  14 *
  15 * This program is distributed in the hope that it will be useful,
  16 * but WITHOUT ANY WARRANTY; without even the implied warranty of
  17 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  18 * GNU General Public License for more details.
  19 *
  20 */
  21
  22#include <linux/device.h>
  23#include <linux/module.h>
  24#include <linux/sched.h>
  25#include <linux/slab.h>
  26#include <media/rc-core.h>
  27
  28#define DRIVER_NAME     "rc-loopback"
  29#define dprintk(x...)   if (debug) printk(KERN_INFO DRIVER_NAME ": " x)
  30#define RXMASK_REGULAR  0x1
  31#define RXMASK_LEARNING 0x2
  32
  33static bool debug;
  34
  35struct loopback_dev {
  36        struct rc_dev *dev;
  37        u32 txmask;
  38        u32 txcarrier;
  39        u32 txduty;
  40        bool idle;
  41        bool learning;
  42        bool carrierreport;
  43        u32 rxcarriermin;
  44        u32 rxcarriermax;
  45};
  46
  47static struct loopback_dev loopdev;
  48
  49static int loop_set_tx_mask(struct rc_dev *dev, u32 mask)
  50{
  51        struct loopback_dev *lodev = dev->priv;
  52
  53        if ((mask & (RXMASK_REGULAR | RXMASK_LEARNING)) != mask) {
  54                dprintk("invalid tx mask: %u\n", mask);
  55                return -EINVAL;
  56        }
  57
  58        dprintk("setting tx mask: %u\n", mask);
  59        lodev->txmask = mask;
  60        return 0;
  61}
  62
  63static int loop_set_tx_carrier(struct rc_dev *dev, u32 carrier)
  64{
  65        struct loopback_dev *lodev = dev->priv;
  66
  67        dprintk("setting tx carrier: %u\n", carrier);
  68        lodev->txcarrier = carrier;
  69        return 0;
  70}
  71
  72static int loop_set_tx_duty_cycle(struct rc_dev *dev, u32 duty_cycle)
  73{
  74        struct loopback_dev *lodev = dev->priv;
  75
  76        if (duty_cycle < 1 || duty_cycle > 99) {
  77                dprintk("invalid duty cycle: %u\n", duty_cycle);
  78                return -EINVAL;
  79        }
  80
  81        dprintk("setting duty cycle: %u\n", duty_cycle);
  82        lodev->txduty = duty_cycle;
  83        return 0;
  84}
  85
  86static int loop_set_rx_carrier_range(struct rc_dev *dev, u32 min, u32 max)
  87{
  88        struct loopback_dev *lodev = dev->priv;
  89
  90        if (min < 1 || min > max) {
  91                dprintk("invalid rx carrier range %u to %u\n", min, max);
  92                return -EINVAL;
  93        }
  94
  95        dprintk("setting rx carrier range %u to %u\n", min, max);
  96        lodev->rxcarriermin = min;
  97        lodev->rxcarriermax = max;
  98        return 0;
  99}
 100
 101static int loop_tx_ir(struct rc_dev *dev, unsigned *txbuf, unsigned count)
 102{
 103        struct loopback_dev *lodev = dev->priv;
 104        u32 rxmask;
 105        unsigned i;
 106        DEFINE_IR_RAW_EVENT(rawir);
 107
 108        if (lodev->txcarrier < lodev->rxcarriermin ||
 109            lodev->txcarrier > lodev->rxcarriermax) {
 110                dprintk("ignoring tx, carrier out of range\n");
 111                goto out;
 112        }
 113
 114        if (lodev->learning)
 115                rxmask = RXMASK_LEARNING;
 116        else
 117                rxmask = RXMASK_REGULAR;
 118
 119        if (!(rxmask & lodev->txmask)) {
 120                dprintk("ignoring tx, rx mask mismatch\n");
 121                goto out;
 122        }
 123
 124        for (i = 0; i < count; i++) {
 125                rawir.pulse = i % 2 ? false : true;
 126                rawir.duration = txbuf[i] * 1000;
 127                if (rawir.duration)
 128                        ir_raw_event_store_with_filter(dev, &rawir);
 129        }
 130
 131        /* Fake a silence long enough to cause us to go idle */
 132        rawir.pulse = false;
 133        rawir.duration = dev->timeout;
 134        ir_raw_event_store_with_filter(dev, &rawir);
 135
 136        ir_raw_event_handle(dev);
 137
 138out:
 139        return count;
 140}
 141
 142static void loop_set_idle(struct rc_dev *dev, bool enable)
 143{
 144        struct loopback_dev *lodev = dev->priv;
 145
 146        if (lodev->idle != enable) {
 147                dprintk("%sing idle mode\n", enable ? "enter" : "exit");
 148                lodev->idle = enable;
 149        }
 150}
 151
 152static int loop_set_learning_mode(struct rc_dev *dev, int enable)
 153{
 154        struct loopback_dev *lodev = dev->priv;
 155
 156        if (lodev->learning != enable) {
 157                dprintk("%sing learning mode\n", enable ? "enter" : "exit");
 158                lodev->learning = !!enable;
 159        }
 160
 161        return 0;
 162}
 163
 164static int loop_set_carrier_report(struct rc_dev *dev, int enable)
 165{
 166        struct loopback_dev *lodev = dev->priv;
 167
 168        if (lodev->carrierreport != enable) {
 169                dprintk("%sabling carrier reports\n", enable ? "en" : "dis");
 170                lodev->carrierreport = !!enable;
 171        }
 172
 173        return 0;
 174}
 175
 176static int loop_set_wakeup_filter(struct rc_dev *dev,
 177                                  struct rc_scancode_filter *sc)
 178{
 179        static const unsigned int max = 512;
 180        struct ir_raw_event *raw;
 181        int ret;
 182        int i;
 183
 184        /* fine to disable filter */
 185        if (!sc->mask)
 186                return 0;
 187
 188        /* encode the specified filter and loop it back */
 189        raw = kmalloc_array(max, sizeof(*raw), GFP_KERNEL);
 190        if (!raw)
 191                return -ENOMEM;
 192
 193        ret = ir_raw_encode_scancode(dev->wakeup_protocol, sc->data, raw, max);
 194        /* still loop back the partial raw IR even if it's incomplete */
 195        if (ret == -ENOBUFS)
 196                ret = max;
 197        if (ret >= 0) {
 198                /* do the loopback */
 199                for (i = 0; i < ret; ++i)
 200                        ir_raw_event_store(dev, &raw[i]);
 201                ir_raw_event_handle(dev);
 202
 203                ret = 0;
 204        }
 205
 206        kfree(raw);
 207
 208        return ret;
 209}
 210
 211static int __init loop_init(void)
 212{
 213        struct rc_dev *rc;
 214        int ret;
 215
 216        rc = rc_allocate_device(RC_DRIVER_IR_RAW);
 217        if (!rc) {
 218                printk(KERN_ERR DRIVER_NAME ": rc_dev allocation failed\n");
 219                return -ENOMEM;
 220        }
 221
 222        rc->device_name         = "rc-core loopback device";
 223        rc->input_phys          = "rc-core/virtual";
 224        rc->input_id.bustype    = BUS_VIRTUAL;
 225        rc->input_id.version    = 1;
 226        rc->driver_name         = DRIVER_NAME;
 227        rc->map_name            = RC_MAP_EMPTY;
 228        rc->priv                = &loopdev;
 229        rc->allowed_protocols   = RC_PROTO_BIT_ALL_IR_DECODER;
 230        rc->allowed_wakeup_protocols = RC_PROTO_BIT_ALL_IR_ENCODER;
 231        rc->encode_wakeup       = true;
 232        rc->timeout             = 100 * 1000 * 1000; /* 100 ms */
 233        rc->min_timeout         = 1;
 234        rc->max_timeout         = UINT_MAX;
 235        rc->rx_resolution       = 1000;
 236        rc->tx_resolution       = 1000;
 237        rc->s_tx_mask           = loop_set_tx_mask;
 238        rc->s_tx_carrier        = loop_set_tx_carrier;
 239        rc->s_tx_duty_cycle     = loop_set_tx_duty_cycle;
 240        rc->s_rx_carrier_range  = loop_set_rx_carrier_range;
 241        rc->tx_ir               = loop_tx_ir;
 242        rc->s_idle              = loop_set_idle;
 243        rc->s_learning_mode     = loop_set_learning_mode;
 244        rc->s_carrier_report    = loop_set_carrier_report;
 245        rc->s_wakeup_filter     = loop_set_wakeup_filter;
 246
 247        loopdev.txmask          = RXMASK_REGULAR;
 248        loopdev.txcarrier       = 36000;
 249        loopdev.txduty          = 50;
 250        loopdev.rxcarriermin    = 1;
 251        loopdev.rxcarriermax    = ~0;
 252        loopdev.idle            = true;
 253        loopdev.learning        = false;
 254        loopdev.carrierreport   = false;
 255
 256        ret = rc_register_device(rc);
 257        if (ret < 0) {
 258                printk(KERN_ERR DRIVER_NAME ": rc_dev registration failed\n");
 259                rc_free_device(rc);
 260                return ret;
 261        }
 262
 263        loopdev.dev = rc;
 264        return 0;
 265}
 266
 267static void __exit loop_exit(void)
 268{
 269        rc_unregister_device(loopdev.dev);
 270}
 271
 272module_init(loop_init);
 273module_exit(loop_exit);
 274
 275module_param(debug, bool, S_IRUGO | S_IWUSR);
 276MODULE_PARM_DESC(debug, "Enable debug messages");
 277
 278MODULE_DESCRIPTION("Loopback device for rc-core debugging");
 279MODULE_AUTHOR("David Härdeman <david@hardeman.nu>");
 280MODULE_LICENSE("GPL");
 281