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}