drivers/isdn/mISDN/dsp_hwec.c

   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
  36 static struct mISDN_dsp_element_arg args[] = {
  37         { "deftaps", "128", "Set the number of taps of cancellation." },
  38 };
  39
  40 static 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 };
  49 struct mISDN_dsp_element *dsp_hwec = &dsp_hwec_p;
  50
  51 void 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
 107 void 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
 127 int dsp_hwec_init(void)
 128 {
 129         mISDN_dsp_element_register(dsp_hwec);
 130
 131         return 0;
 132 }
 133
 134 void dsp_hwec_exit(void)
 135 {
 136         mISDN_dsp_element_unregister(dsp_hwec);
 137 }