drivers/isdn/mISDN/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
  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
  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
  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
 112 int dsp_hwec_init(void)
 113 {
 114         mISDN_dsp_element_register(dsp_hwec);
 115
 116         return 0;
 117 }
 118
 119 void dsp_hwec_exit(void)
 120 {
 121         mISDN_dsp_element_unregister(dsp_hwec);
 122 }