xref: /openbmc/linux/drivers/isdn/mISDN/dsp_hwec.c (revision f220d3eb)
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 
36 static struct mISDN_dsp_element_arg args[] = {
37 	{ "deftaps", "128", "Set the number of taps of cancellation." },
38 };
39 
40 static 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 };
49 struct mISDN_dsp_element *dsp_hwec = &dsp_hwec_p;
50 
51 void 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, *tok, *name, *val;
72 		int tmp;
73 
74 		dup = kstrdup(arg, GFP_ATOMIC);
75 		if (!dup)
76 			return;
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 		kfree(dup);
94 	}
95 
96 _do:
97 	printk(KERN_DEBUG "%s: enabling hwec with deftaps=%d\n",
98 	       __func__, deftaps);
99 	memset(&cq, 0, sizeof(cq));
100 	cq.op = MISDN_CTRL_HFC_ECHOCAN_ON;
101 	cq.p1 = deftaps;
102 	if (!dsp->ch.peer->ctrl(&dsp->ch, CONTROL_CHANNEL, &cq)) {
103 		printk(KERN_DEBUG "%s: CONTROL_CHANNEL failed\n",
104 		       __func__);
105 		return;
106 	}
107 }
108 
109 void dsp_hwec_disable(struct dsp *dsp)
110 {
111 	struct mISDN_ctrl_req	cq;
112 
113 	if (!dsp) {
114 		printk(KERN_ERR "%s: failed to disable hwec: dsp is NULL\n",
115 		       __func__);
116 		return;
117 	}
118 
119 	printk(KERN_DEBUG "%s: disabling hwec\n", __func__);
120 	memset(&cq, 0, sizeof(cq));
121 	cq.op = MISDN_CTRL_HFC_ECHOCAN_OFF;
122 	if (!dsp->ch.peer->ctrl(&dsp->ch, CONTROL_CHANNEL, &cq)) {
123 		printk(KERN_DEBUG "%s: CONTROL_CHANNEL failed\n",
124 		       __func__);
125 		return;
126 	}
127 }
128 
129 int dsp_hwec_init(void)
130 {
131 	mISDN_dsp_element_register(dsp_hwec);
132 
133 	return 0;
134 }
135 
136 void dsp_hwec_exit(void)
137 {
138 	mISDN_dsp_element_unregister(dsp_hwec);
139 }
140