xref: /openbmc/linux/drivers/isdn/mISDN/dsp_hwec.c (revision 9e567af4)
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 
19 static struct mISDN_dsp_element_arg args[] = {
20 	{ "deftaps", "128", "Set the number of taps of cancellation." },
21 };
22 
23 static 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 };
32 struct mISDN_dsp_element *dsp_hwec = &dsp_hwec_p;
33 
dsp_hwec_enable(struct dsp * dsp,const char * arg)34 void 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 
dsp_hwec_disable(struct dsp * dsp)92 void 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 
dsp_hwec_init(void)112 int dsp_hwec_init(void)
113 {
114 	mISDN_dsp_element_register(dsp_hwec);
115 
116 	return 0;
117 }
118 
dsp_hwec_exit(void)119 void dsp_hwec_exit(void)
120 {
121 	mISDN_dsp_element_unregister(dsp_hwec);
122 }
123