dsp_hwec.c

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/*
 * dsp_hwec.c:
 * builtin mISDN dsp pipeline element for enabling the hw echocanceller
 *
 * Copyright (C) 2007, Nadi Sarrar
 *
 * Nadi Sarrar <[email protected]>
 *
 * 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.
 *
 * The full GNU General Public License is included in this distribution in the
 * file called LICENSE.
 *
 */

#include <linux/kernel.h>
#include <linux/string.h>
#include <linux/mISDNdsp.h>
#include <linux/mISDNif.h>
#include "core.h"
#include "dsp.h"
#include "dsp_hwec.h"

static struct mISDN_dsp_element_arg args[] = {
    { "deftaps", "128", "Set the number of taps of cancellation." },
};

static struct mISDN_dsp_element dsp_hwec_p = {
    .name = "hwec",
    .new = NULL,
    .free = NULL,
    .process_tx = NULL,
    .process_rx = NULL,
    .num_args = ARRAY_SIZE(args),
    .args = args,
};
struct mISDN_dsp_element *dsp_hwec = &dsp_hwec_p;

void dsp_hwec_enable(struct dsp *dsp, const char *arg)
{
    int deftaps = 128,
        len;
    struct mISDN_ctrl_req   cq;

    if (!dsp) {
        printk(KERN_ERR "%s: failed to enable hwec: dsp is NULL\n",
               __func__);
        return;
    }

    if (!arg)
        goto _do;

    len = strlen(arg);
    if (!len)
        goto _do;

    {
        char _dup[len + 1];
        char *dup, *tok, *name, *val;
        int tmp;

        strcpy(_dup, arg);
        dup = _dup;

        while ((tok = strsep(&dup, ","))) {
            if (!strlen(tok))
                continue;
            name = strsep(&tok, "=");
            val = tok;

            if (!val)
                continue;

            if (!strcmp(name, "deftaps")) {
                if (sscanf(val, "%d", &tmp) == 1)
                    deftaps = tmp;
            }
        }
    }

_do:
    printk(KERN_DEBUG "%s: enabling hwec with deftaps=%d\n",
           __func__, deftaps);
    memset(&cq, 0, sizeof(cq));
    cq.op = MISDN_CTRL_HFC_ECHOCAN_ON;
    cq.p1 = deftaps;
    if (!dsp->ch.peer->ctrl(&dsp->ch, CONTROL_CHANNEL, &cq)) {
        printk(KERN_DEBUG "%s: CONTROL_CHANNEL failed\n",
               __func__);
        return;
    }
}

void dsp_hwec_disable(struct dsp *dsp)
{
    struct mISDN_ctrl_req   cq;

    if (!dsp) {
        printk(KERN_ERR "%s: failed to disable hwec: dsp is NULL\n",
               __func__);
        return;
    }

    printk(KERN_DEBUG "%s: disabling hwec\n", __func__);
    memset(&cq, 0, sizeof(cq));
    cq.op = MISDN_CTRL_HFC_ECHOCAN_OFF;
    if (!dsp->ch.peer->ctrl(&dsp->ch, CONTROL_CHANNEL, &cq)) {
        printk(KERN_DEBUG "%s: CONTROL_CHANNEL failed\n",
               __func__);
        return;
    }
}

int dsp_hwec_init(void)
{
    mISDN_dsp_element_register(dsp_hwec);

    return 0;
}

void dsp_hwec_exit(void)
{
    mISDN_dsp_element_unregister(dsp_hwec);
}