drivers/media/rc/rc-loopback.c

   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
  33 static bool debug;
  34
  35 struct 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
  47 static struct loopback_dev loopdev;
  48
  49 static 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
  63 static 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
  72 static 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
  86 static 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
 101 static 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
 138 out:
 139         return count;
 140 }
 141
 142 static 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
 152 static 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
 164 static 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
 176 static 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
 211 static 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
 267 static void __exit loop_exit(void)
 268 {
 269         rc_unregister_device(loopdev.dev);
 270 }
 271
 272 module_init(loop_init);
 273 module_exit(loop_exit);
 274
 275 module_param(debug, bool, S_IRUGO | S_IWUSR);
 276 MODULE_PARM_DESC(debug, "Enable debug messages");
 277
 278 MODULE_DESCRIPTION("Loopback device for rc-core debugging");
 279 MODULE_AUTHOR("David Härdeman <david@hardeman.nu>");
 280 MODULE_LICENSE("GPL");