rc-loopback.c

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/*
 * Loopback driver for rc-core,
 *
 * Copyright (c) 2010 David Härdeman <[email protected]>
 *
 * This driver receives TX data and passes it back as RX data,
 * which is useful for (scripted) debugging of rc-core without
 * having to use actual hardware.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
 *
 */

#include <linux/device.h>
#include <linux/module.h>
#include <linux/sched.h>
#include <media/rc-core.h>

#define DRIVER_NAME "rc-loopback"
#define dprintk(x...)   if (debug) printk(KERN_INFO DRIVER_NAME ": " x)
#define RXMASK_REGULAR  0x1
#define RXMASK_LEARNING 0x2

static bool debug;

struct loopback_dev {
    struct rc_dev *dev;
    u32 txmask;
    u32 txcarrier;
    u32 txduty;
    bool idle;
    bool learning;
    bool carrierreport;
    u32 rxcarriermin;
    u32 rxcarriermax;
};

static struct loopback_dev loopdev;

static int loop_set_tx_mask(struct rc_dev *dev, u32 mask)
{
    struct loopback_dev *lodev = dev->priv;

    if ((mask & (RXMASK_REGULAR | RXMASK_LEARNING)) != mask) {
        dprintk("invalid tx mask: %u\n", mask);
        return -EINVAL;
    }

    dprintk("setting tx mask: %u\n", mask);
    lodev->txmask = mask;
    return 0;
}

static int loop_set_tx_carrier(struct rc_dev *dev, u32 carrier)
{
    struct loopback_dev *lodev = dev->priv;

    dprintk("setting tx carrier: %u\n", carrier);
    lodev->txcarrier = carrier;
    return 0;
}

static int loop_set_tx_duty_cycle(struct rc_dev *dev, u32 duty_cycle)
{
    struct loopback_dev *lodev = dev->priv;

    if (duty_cycle < 1 || duty_cycle > 99) {
        dprintk("invalid duty cycle: %u\n", duty_cycle);
        return -EINVAL;
    }

    dprintk("setting duty cycle: %u\n", duty_cycle);
    lodev->txduty = duty_cycle;
    return 0;
}

static int loop_set_rx_carrier_range(struct rc_dev *dev, u32 min, u32 max)
{
    struct loopback_dev *lodev = dev->priv;

    if (min < 1 || min > max) {
        dprintk("invalid rx carrier range %u to %u\n", min, max);
        return -EINVAL;
    }

    dprintk("setting rx carrier range %u to %u\n", min, max);
    lodev->rxcarriermin = min;
    lodev->rxcarriermax = max;
    return 0;
}

static int loop_tx_ir(struct rc_dev *dev, unsigned *txbuf, unsigned count)
{
    struct loopback_dev *lodev = dev->priv;
    u32 rxmask;
    unsigned i;
    DEFINE_IR_RAW_EVENT(rawir);

    if (lodev->txcarrier < lodev->rxcarriermin ||
        lodev->txcarrier > lodev->rxcarriermax) {
        dprintk("ignoring tx, carrier out of range\n");
        goto out;
    }

    if (lodev->learning)
        rxmask = RXMASK_LEARNING;
    else
        rxmask = RXMASK_REGULAR;

    if (!(rxmask & lodev->txmask)) {
        dprintk("ignoring tx, rx mask mismatch\n");
        goto out;
    }

    for (i = 0; i < count; i++) {
        rawir.pulse = i % 2 ? false : true;
        rawir.duration = txbuf[i] * 1000;
        if (rawir.duration)
            ir_raw_event_store_with_filter(dev, &rawir);
    }

    /* Fake a silence long enough to cause us to go idle */
    rawir.pulse = false;
    rawir.duration = dev->timeout;
    ir_raw_event_store_with_filter(dev, &rawir);

    ir_raw_event_handle(dev);

out:
    return count;
}

static void loop_set_idle(struct rc_dev *dev, bool enable)
{
    struct loopback_dev *lodev = dev->priv;

    if (lodev->idle != enable) {
        dprintk("%sing idle mode\n", enable ? "enter" : "exit");
        lodev->idle = enable;
    }
}

static int loop_set_learning_mode(struct rc_dev *dev, int enable)
{
    struct loopback_dev *lodev = dev->priv;

    if (lodev->learning != enable) {
        dprintk("%sing learning mode\n", enable ? "enter" : "exit");
        lodev->learning = !!enable;
    }

    return 0;
}

static int loop_set_carrier_report(struct rc_dev *dev, int enable)
{
    struct loopback_dev *lodev = dev->priv;

    if (lodev->carrierreport != enable) {
        dprintk("%sabling carrier reports\n", enable ? "en" : "dis");
        lodev->carrierreport = !!enable;
    }

    return 0;
}

static int __init loop_init(void)
{
    struct rc_dev *rc;
    int ret;

    rc = rc_allocate_device();
    if (!rc) {
        printk(KERN_ERR DRIVER_NAME ": rc_dev allocation failed\n");
        return -ENOMEM;
    }

    rc->input_name      = "rc-core loopback device";
    rc->input_phys      = "rc-core/virtual";
    rc->input_id.bustype    = BUS_VIRTUAL;
    rc->input_id.version    = 1;
    rc->driver_name     = DRIVER_NAME;
    rc->map_name        = RC_MAP_EMPTY;
    rc->priv        = &loopdev;
    rc->driver_type     = RC_DRIVER_IR_RAW;
    rc->allowed_protos  = RC_TYPE_ALL;
    rc->timeout     = 100 * 1000 * 1000; /* 100 ms */
    rc->min_timeout     = 1;
    rc->max_timeout     = UINT_MAX;
    rc->rx_resolution   = 1000;
    rc->tx_resolution   = 1000;
    rc->s_tx_mask       = loop_set_tx_mask;
    rc->s_tx_carrier    = loop_set_tx_carrier;
    rc->s_tx_duty_cycle = loop_set_tx_duty_cycle;
    rc->s_rx_carrier_range  = loop_set_rx_carrier_range;
    rc->tx_ir       = loop_tx_ir;
    rc->s_idle      = loop_set_idle;
    rc->s_learning_mode = loop_set_learning_mode;
    rc->s_carrier_report    = loop_set_carrier_report;

    loopdev.txmask      = RXMASK_REGULAR;
    loopdev.txcarrier   = 36000;
    loopdev.txduty      = 50;
    loopdev.rxcarriermin    = 1;
    loopdev.rxcarriermax    = ~0;
    loopdev.idle        = true;
    loopdev.learning    = false;
    loopdev.carrierreport   = false;

    ret = rc_register_device(rc);
    if (ret < 0) {
        printk(KERN_ERR DRIVER_NAME ": rc_dev registration failed\n");
        rc_free_device(rc);
        return ret;
    }

    loopdev.dev = rc;
    return 0;
}

static void __exit loop_exit(void)
{
    rc_unregister_device(loopdev.dev);
}

module_init(loop_init);
module_exit(loop_exit);

module_param(debug, bool, S_IRUGO | S_IWUSR);
MODULE_PARM_DESC(debug, "Enable debug messages");

MODULE_DESCRIPTION("Loopback device for rc-core debugging");
MODULE_AUTHOR("David Härdeman <[email protected]>");
MODULE_LICENSE("GPL");