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, *tok, *name, *val;
55		int tmp;
56
57		dup = kstrdup(arg, GFP_ATOMIC);
58		if (!dup)
59			return;
60
61		while ((tok = strsep(&dup, ","))) {
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}
123