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(s: 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(objp: 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(elem: dsp_hwec);
115
116 return 0;
117}
118
119void dsp_hwec_exit(void)
120{
121 mISDN_dsp_element_unregister(elem: dsp_hwec);
122}
123

source code of linux/drivers/isdn/mISDN/dsp_hwec.c