LXR linux/drivers/isdn/mISDN/dsp

   1/*
   2 * dsp_hwec.c:
   3 * builtin mISDN dsp pipeline element for enabling the hw echocanceller
   4 *
   5 * Copyright (C) 2007, Nadi Sarrar
   6 *
   7 * Nadi Sarrar <nadi@beronet.com>
   8 *
   9 * This program is free software; you can redistribute it and/or modify it
  10 * under the terms of the GNU General Public License as published by the Free
  11 * Software Foundation; either version 2 of the License, or (at your option)
  12 * any later version.
  13 *
  14 * This program is distributed in the hope that it will be useful, but WITHOUT
  15 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  16 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
  17 * more details.
  18 *
  19 * You should have received a copy of the GNU General Public License along with
  20 * this program; if not, write to the Free Software Foundation, Inc., 59
  21 * Temple Place - Suite 330, Boston, MA  02111-1307, USA.
  22 *
  23 * The full GNU General Public License is included in this distribution in the
  24 * file called LICENSE.
  25 *
  26 */
  27
  28#include <linux/kernel.h>
  29#include <linux/string.h>
  30#include <linux/mISDNdsp.h>
  31#include <linux/mISDNif.h>
  32#include "core.h"
  33#include "dsp.h"
  34#include "dsp_hwec.h"
  35
  36static struct mISDN_dsp_element_arg args[] = {
  37        { "deftaps", "128", "Set the number of taps of cancellation." },
  38};
  39
  40static struct mISDN_dsp_element dsp_hwec_p = {
  41        .name = "hwec",
  42        .new = NULL,
  43        .free = NULL,
  44        .process_tx = NULL,
  45        .process_rx = NULL,
  46        .num_args = ARRAY_SIZE(args),
  47        .args = args,
  48};
  49struct mISDN_dsp_element *dsp_hwec = &dsp_hwec_p;
  50
  51void dsp_hwec_enable(struct dsp *dsp, const char *arg)
  52{
  53        int deftaps = 128,
  54                len;
  55        struct mISDN_ctrl_req   cq;
  56
  57        if (!dsp) {
  58                printk(KERN_ERR "%s: failed to enable hwec: dsp is NULL\n",
  59                       __func__);
  60                return;
  61        }
  62
  63        if (!arg)
  64                goto _do;
  65
  66        len = strlen(arg);
  67        if (!len)
  68                goto _do;
  69
  70        {
  71                char _dup[len + 1];
  72                char *dup, *tok, *name, *val;
  73                int tmp;
  74
  75                strcpy(_dup, arg);
  76                dup = _dup;
  77
  78                while ((tok = strsep(&dup, ","))) {
  79                        if (!strlen(tok))
  80                                continue;
  81                        name = strsep(&tok, "=");
  82                        val = tok;
  83
  84                        if (!val)
  85                                continue;
  86
  87                        if (!strcmp(name, "deftaps")) {
  88                                if (sscanf(val, "%d", &tmp) == 1)
  89                                        deftaps = tmp;
  90                        }
  91                }
  92        }
  93
  94_do:
  95        printk(KERN_DEBUG "%s: enabling hwec with deftaps=%d\n",
  96               __func__, deftaps);
  97        memset(&cq, 0, sizeof(cq));
  98        cq.op = MISDN_CTRL_HFC_ECHOCAN_ON;
  99        cq.p1 = deftaps;
 100        if (!dsp->ch.peer->ctrl(&dsp->ch, CONTROL_CHANNEL, &cq)) {
 101                printk(KERN_DEBUG "%s: CONTROL_CHANNEL failed\n",
 102                       __func__);
 103                return;
 104        }
 105}
 106
 107void dsp_hwec_disable(struct dsp *dsp)
 108{
 109        struct mISDN_ctrl_req   cq;
 110
 111        if (!dsp) {
 112                printk(KERN_ERR "%s: failed to disable hwec: dsp is NULL\n",
 113                       __func__);
 114                return;
 115        }
 116
 117        printk(KERN_DEBUG "%s: disabling hwec\n", __func__);
 118        memset(&cq, 0, sizeof(cq));
 119        cq.op = MISDN_CTRL_HFC_ECHOCAN_OFF;
 120        if (!dsp->ch.peer->ctrl(&dsp->ch, CONTROL_CHANNEL, &cq)) {
 121                printk(KERN_DEBUG "%s: CONTROL_CHANNEL failed\n",
 122                       __func__);
 123                return;
 124        }
 125}
 126
 127int dsp_hwec_init(void)
 128{
 129        mISDN_dsp_element_register(dsp_hwec);
 130
 131        return 0;
 132}
 133
 134void dsp_hwec_exit(void)
 135{
 136        mISDN_dsp_element_unregister(dsp_hwec);
 137}
 138