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  * You should have received a copy of the GNU General Public License
  21  * along with this program; if not, write to the Free Software
  22  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
  23  *
  24  */
  25
  26 #include <linux/device.h>
  27 #include <linux/module.h>
  28 #include <linux/sched.h>
  29 #include <media/rc-core.h>
  30
  31 #define DRIVER_NAME     "rc-loopback"
  32 #define dprintk(x...)   if (debug) printk(KERN_INFO DRIVER_NAME ": " x)
  33 #define RXMASK_REGULAR  0x1
  34 #define RXMASK_LEARNING 0x2
  35
  36 static bool debug;
  37
  38 struct loopback_dev {
  39         struct rc_dev *dev;
  40         u32 txmask;
  41         u32 txcarrier;
  42         u32 txduty;
  43         bool idle;
  44         bool learning;
  45         bool carrierreport;
  46         u32 rxcarriermin;
  47         u32 rxcarriermax;
  48 };
  49
  50 static struct loopback_dev loopdev;
  51
  52 static int loop_set_tx_mask(struct rc_dev *dev, u32 mask)
  53 {
  54         struct loopback_dev *lodev = dev->priv;
  55
  56         if ((mask & (RXMASK_REGULAR | RXMASK_LEARNING)) != mask) {
  57                 dprintk("invalid tx mask: %u\n", mask);
  58                 return -EINVAL;
  59         }
  60
  61         dprintk("setting tx mask: %u\n", mask);
  62         lodev->txmask = mask;
  63         return 0;
  64 }
  65
  66 static int loop_set_tx_carrier(struct rc_dev *dev, u32 carrier)
  67 {
  68         struct loopback_dev *lodev = dev->priv;
  69
  70         dprintk("setting tx carrier: %u\n", carrier);
  71         lodev->txcarrier = carrier;
  72         return 0;
  73 }
  74
  75 static int loop_set_tx_duty_cycle(struct rc_dev *dev, u32 duty_cycle)
  76 {
  77         struct loopback_dev *lodev = dev->priv;
  78
  79         if (duty_cycle < 1 || duty_cycle > 99) {
  80                 dprintk("invalid duty cycle: %u\n", duty_cycle);
  81                 return -EINVAL;
  82         }
  83
  84         dprintk("setting duty cycle: %u\n", duty_cycle);
  85         lodev->txduty = duty_cycle;
  86         return 0;
  87 }
  88
  89 static int loop_set_rx_carrier_range(struct rc_dev *dev, u32 min, u32 max)
  90 {
  91         struct loopback_dev *lodev = dev->priv;
  92
  93         if (min < 1 || min > max) {
  94                 dprintk("invalid rx carrier range %u to %u\n", min, max);
  95                 return -EINVAL;
  96         }
  97
  98         dprintk("setting rx carrier range %u to %u\n", min, max);
  99         lodev->rxcarriermin = min;
 100         lodev->rxcarriermax = max;
 101         return 0;
 102 }
 103
 104 static int loop_tx_ir(struct rc_dev *dev, unsigned *txbuf, unsigned count)
 105 {
 106         struct loopback_dev *lodev = dev->priv;
 107         u32 rxmask;
 108         unsigned total_duration = 0;
 109         unsigned i;
 110         DEFINE_IR_RAW_EVENT(rawir);
 111
 112         for (i = 0; i < count; i++)
 113                 total_duration += abs(txbuf[i]);
 114
 115         if (total_duration == 0) {
 116                 dprintk("invalid tx data, total duration zero\n");
 117                 return -EINVAL;
 118         }
 119
 120         if (lodev->txcarrier < lodev->rxcarriermin ||
 121             lodev->txcarrier > lodev->rxcarriermax) {
 122                 dprintk("ignoring tx, carrier out of range\n");
 123                 goto out;
 124         }
 125
 126         if (lodev->learning)
 127                 rxmask = RXMASK_LEARNING;
 128         else
 129                 rxmask = RXMASK_REGULAR;
 130
 131         if (!(rxmask & lodev->txmask)) {
 132                 dprintk("ignoring tx, rx mask mismatch\n");
 133                 goto out;
 134         }
 135
 136         for (i = 0; i < count; i++) {
 137                 rawir.pulse = i % 2 ? false : true;
 138                 rawir.duration = txbuf[i] * 1000;
 139                 if (rawir.duration)
 140                         ir_raw_event_store_with_filter(dev, &rawir);
 141         }
 142
 143         /* Fake a silence long enough to cause us to go idle */
 144         rawir.pulse = false;
 145         rawir.duration = dev->timeout;
 146         ir_raw_event_store_with_filter(dev, &rawir);
 147
 148         ir_raw_event_handle(dev);
 149
 150 out:
 151         /* Lirc expects this function to take as long as the total duration */
 152         set_current_state(TASK_INTERRUPTIBLE);
 153         schedule_timeout(usecs_to_jiffies(total_duration));
 154         return count;
 155 }
 156
 157 static void loop_set_idle(struct rc_dev *dev, bool enable)
 158 {
 159         struct loopback_dev *lodev = dev->priv;
 160
 161         if (lodev->idle != enable) {
 162                 dprintk("%sing idle mode\n", enable ? "enter" : "exit");
 163                 lodev->idle = enable;
 164         }
 165 }
 166
 167 static int loop_set_learning_mode(struct rc_dev *dev, int enable)
 168 {
 169         struct loopback_dev *lodev = dev->priv;
 170
 171         if (lodev->learning != enable) {
 172                 dprintk("%sing learning mode\n", enable ? "enter" : "exit");
 173                 lodev->learning = !!enable;
 174         }
 175
 176         return 0;
 177 }
 178
 179 static int loop_set_carrier_report(struct rc_dev *dev, int enable)
 180 {
 181         struct loopback_dev *lodev = dev->priv;
 182
 183         if (lodev->carrierreport != enable) {
 184                 dprintk("%sabling carrier reports\n", enable ? "en" : "dis");
 185                 lodev->carrierreport = !!enable;
 186         }
 187
 188         return 0;
 189 }
 190
 191 static int __init loop_init(void)
 192 {
 193         struct rc_dev *rc;
 194         int ret;
 195
 196         rc = rc_allocate_device();
 197         if (!rc) {
 198                 printk(KERN_ERR DRIVER_NAME ": rc_dev allocation failed\n");
 199                 return -ENOMEM;
 200         }
 201
 202         rc->input_name          = "rc-core loopback device";
 203         rc->input_phys          = "rc-core/virtual";
 204         rc->input_id.bustype    = BUS_VIRTUAL;
 205         rc->input_id.version    = 1;
 206         rc->driver_name         = DRIVER_NAME;
 207         rc->map_name            = RC_MAP_EMPTY;
 208         rc->priv                = &loopdev;
 209         rc->driver_type         = RC_DRIVER_IR_RAW;
 210         rc->allowed_protos      = RC_TYPE_ALL;
 211         rc->timeout             = 100 * 1000 * 1000; /* 100 ms */
 212         rc->min_timeout         = 1;
 213         rc->max_timeout         = UINT_MAX;
 214         rc->rx_resolution       = 1000;
 215         rc->tx_resolution       = 1000;
 216         rc->s_tx_mask           = loop_set_tx_mask;
 217         rc->s_tx_carrier        = loop_set_tx_carrier;
 218         rc->s_tx_duty_cycle     = loop_set_tx_duty_cycle;
 219         rc->s_rx_carrier_range  = loop_set_rx_carrier_range;
 220         rc->tx_ir               = loop_tx_ir;
 221         rc->s_idle              = loop_set_idle;
 222         rc->s_learning_mode     = loop_set_learning_mode;
 223         rc->s_carrier_report    = loop_set_carrier_report;
 224
 225         loopdev.txmask          = RXMASK_REGULAR;
 226         loopdev.txcarrier       = 36000;
 227         loopdev.txduty          = 50;
 228         loopdev.rxcarriermin    = 1;
 229         loopdev.rxcarriermax    = ~0;
 230         loopdev.idle            = true;
 231         loopdev.learning        = false;
 232         loopdev.carrierreport   = false;
 233
 234         ret = rc_register_device(rc);
 235         if (ret < 0) {
 236                 printk(KERN_ERR DRIVER_NAME ": rc_dev registration failed\n");
 237                 rc_free_device(rc);
 238                 return ret;
 239         }
 240
 241         loopdev.dev = rc;
 242         return 0;
 243 }
 244
 245 static void __exit loop_exit(void)
 246 {
 247         rc_unregister_device(loopdev.dev);
 248 }
 249
 250 module_init(loop_init);
 251 module_exit(loop_exit);
 252
 253 module_param(debug, bool, S_IRUGO | S_IWUSR);
 254 MODULE_PARM_DESC(debug, "Enable debug messages");
 255
 256 MODULE_DESCRIPTION("Loopback device for rc-core debugging");
 257 MODULE_AUTHOR("David Härdeman <david@hardeman.nu>");
 258 MODULE_LICENSE("GPL");