dsp_hwec.c

  1// SPDX-License-Identifier: GPL-2.0-or-later
  2/*
  3 * dsp_hwec.c:
  4 * builtin mISDN dsp pipeline element for enabling the hw echocanceller
  5 *
  6 * Copyright (C) 2007, Nadi Sarrar
  7 *
  8 * Nadi Sarrar <nadi@beronet.com>
  9 */
 10
 11#include <linux/kernel.h>
 12#include <linux/string.h>
 13#include <linux/mISDNdsp.h>
 14#include <linux/mISDNif.h>
 15#include "core.h"
 16#include "dsp.h"
 17#include "dsp_hwec.h"
 18
 19static struct mISDN_dsp_element_arg args[] = {
 20	{ "deftaps", "128", "Set the number of taps of cancellation." },
 21};
 22
 23static struct mISDN_dsp_element dsp_hwec_p = {
 24	.name = "hwec",
 25	.new = NULL,
 26	.free = NULL,
 27	.process_tx = NULL,
 28	.process_rx = NULL,
 29	.num_args = ARRAY_SIZE(args),
 30	.args = args,
 31};
 32struct mISDN_dsp_element *dsp_hwec = &dsp_hwec_p;
 33
 34void dsp_hwec_enable(struct dsp *dsp, const char *arg)
 35{
 36	int deftaps = 128,
 37		len;
 38	struct mISDN_ctrl_req	cq;
 39
 40	if (!dsp) {
 41		printk(KERN_ERR "%s: failed to enable hwec: dsp is NULL\n",
 42		       __func__);
 43		return;
 44	}
 45
 46	if (!arg)
 47		goto _do;
 48
 49	len = strlen(arg);
 50	if (!len)
 51		goto _do;
 52
 53	{
 54		char *dup, *next, *tok, *name, *val;
 55		int tmp;
 56
 57		dup = next = kstrdup(arg, GFP_ATOMIC);
 58		if (!dup)
 59			return;
 60
 61		while ((tok = strsep(&next, ","))) {
 62			if (!strlen(tok))
 63				continue;
 64			name = strsep(&tok, "=");
 65			val = tok;
 66
 67			if (!val)
 68				continue;
 69
 70			if (!strcmp(name, "deftaps")) {
 71				if (sscanf(val, "%d", &tmp) == 1)
 72					deftaps = tmp;
 73			}
 74		}
 75
 76		kfree(dup);
 77	}
 78
 79_do:
 80	printk(KERN_DEBUG "%s: enabling hwec with deftaps=%d\n",
 81	       __func__, deftaps);
 82	memset(&cq, 0, sizeof(cq));
 83	cq.op = MISDN_CTRL_HFC_ECHOCAN_ON;
 84	cq.p1 = deftaps;
 85	if (!dsp->ch.peer->ctrl(&dsp->ch, CONTROL_CHANNEL, &cq)) {
 86		printk(KERN_DEBUG "%s: CONTROL_CHANNEL failed\n",
 87		       __func__);
 88		return;
 89	}
 90}
 91
 92void dsp_hwec_disable(struct dsp *dsp)
 93{
 94	struct mISDN_ctrl_req	cq;
 95
 96	if (!dsp) {
 97		printk(KERN_ERR "%s: failed to disable hwec: dsp is NULL\n",
 98		       __func__);
 99		return;
100	}
101
102	printk(KERN_DEBUG "%s: disabling hwec\n", __func__);
103	memset(&cq, 0, sizeof(cq));
104	cq.op = MISDN_CTRL_HFC_ECHOCAN_OFF;
105	if (!dsp->ch.peer->ctrl(&dsp->ch, CONTROL_CHANNEL, &cq)) {
106		printk(KERN_DEBUG "%s: CONTROL_CHANNEL failed\n",
107		       __func__);
108		return;
109	}
110}
111
112int dsp_hwec_init(void)
113{
114	mISDN_dsp_element_register(dsp_hwec);
115
116	return 0;
117}
118
119void dsp_hwec_exit(void)
120{
121	mISDN_dsp_element_unregister(dsp_hwec);
122}