drivers/media/pci/ivtv/ivtv-alsa-mixer.c

   1 /*
   2  *  ALSA mixer controls for the
   3  *  ALSA interface to ivtv PCM capture streams
   4  *
   5  *  Copyright (C) 2009,2012  Andy Walls <awalls@md.metrocast.net>
   6  *
   7  *  This program is free software; you can redistribute it and/or modify
   8  *  it under the terms of the GNU General Public License as published by
   9  *  the Free Software Foundation; either version 2 of the License, or
  10  *  (at your option) any later version.
  11  *
  12  *  This program is distributed in the hope that it will be useful,
  13  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15  *  GNU General Public License for more details.
  16  */
  17
  18 #include "ivtv-alsa.h"
  19 #include "ivtv-alsa-mixer.h"
  20 #include "ivtv-driver.h"
  21
  22 #include <linux/videodev2.h>
  23
  24 #include <sound/core.h>
  25 #include <sound/control.h>
  26 #include <sound/tlv.h>
  27
  28 /*
  29  * Note the cx25840-core volume scale is funny, due to the alignment of the
  30  * scale with another chip's range:
  31  *
  32  * v4l2_control value   /512    indicated dB    actual dB       reg 0x8d4
  33  * 0x0000 - 0x01ff        0     -119            -96             228
  34  * 0x0200 - 0x02ff        1     -118            -96             228
  35  * ...
  36  * 0x2c00 - 0x2dff       22      -97            -96             228
  37  * 0x2e00 - 0x2fff       23      -96            -96             228
  38  * 0x3000 - 0x31ff       24      -95            -95             226
  39  * ...
  40  * 0xee00 - 0xefff      119        0              0              36
  41  * ...
  42  * 0xfe00 - 0xffff      127       +8             +8              20
  43  */
  44 static inline int dB_to_cx25840_vol(int dB)
  45 {
  46         if (dB < -96)
  47                 dB = -96;
  48         else if (dB > 8)
  49                 dB = 8;
  50         return (dB + 119) << 9;
  51 }
  52
  53 static inline int cx25840_vol_to_dB(int v)
  54 {
  55         if (v < (23 << 9))
  56                 v = (23 << 9);
  57         else if (v > (127 << 9))
  58                 v = (127 << 9);
  59         return (v >> 9) - 119;
  60 }
  61
  62 static int snd_ivtv_mixer_tv_vol_info(struct snd_kcontrol *kcontrol,
  63                                       struct snd_ctl_elem_info *uinfo)
  64 {
  65         uinfo->type = SNDRV_CTL_ELEM_TYPE_INTEGER;
  66         uinfo->count = 1;
  67         /* We're already translating values, just keep this control in dB */
  68         uinfo->value.integer.min  = -96;
  69         uinfo->value.integer.max  =   8;
  70         uinfo->value.integer.step =   1;
  71         return 0;
  72 }
  73
  74 static int snd_ivtv_mixer_tv_vol_get(struct snd_kcontrol *kctl,
  75                                      struct snd_ctl_elem_value *uctl)
  76 {
  77         struct snd_ivtv_card *itvsc = snd_kcontrol_chip(kctl);
  78         struct ivtv *itv = to_ivtv(itvsc->v4l2_dev);
  79         struct v4l2_control vctrl;
  80         int ret;
  81
  82         vctrl.id = V4L2_CID_AUDIO_VOLUME;
  83         vctrl.value = dB_to_cx25840_vol(uctl->value.integer.value[0]);
  84
  85         snd_ivtv_lock(itvsc);
  86         ret = v4l2_g_ctrl(itv->sd_audio->ctrl_handler, &vctrl);
  87         snd_ivtv_unlock(itvsc);
  88
  89         if (!ret)
  90                 uctl->value.integer.value[0] = cx25840_vol_to_dB(vctrl.value);
  91         return ret;
  92 }
  93
  94 static int snd_ivtv_mixer_tv_vol_put(struct snd_kcontrol *kctl,
  95                                      struct snd_ctl_elem_value *uctl)
  96 {
  97         struct snd_ivtv_card *itvsc = snd_kcontrol_chip(kctl);
  98         struct ivtv *itv = to_ivtv(itvsc->v4l2_dev);
  99         struct v4l2_control vctrl;
 100         int ret;
 101
 102         vctrl.id = V4L2_CID_AUDIO_VOLUME;
 103         vctrl.value = dB_to_cx25840_vol(uctl->value.integer.value[0]);
 104
 105         snd_ivtv_lock(itvsc);
 106
 107         /* Fetch current state */
 108         ret = v4l2_g_ctrl(itv->sd_audio->ctrl_handler, &vctrl);
 109
 110         if (ret ||
 111             (cx25840_vol_to_dB(vctrl.value) != uctl->value.integer.value[0])) {
 112
 113                 /* Set, if needed */
 114                 vctrl.value = dB_to_cx25840_vol(uctl->value.integer.value[0]);
 115                 ret = v4l2_s_ctrl(itv->sd_audio->ctrl_handler, &vctrl);
 116                 if (!ret)
 117                         ret = 1; /* Indicate control was changed w/o error */
 118         }
 119         snd_ivtv_unlock(itvsc);
 120
 121         return ret;
 122 }
 123
 124
 125 /* This is a bit of overkill, the slider is already in dB internally */
 126 static DECLARE_TLV_DB_SCALE(snd_ivtv_mixer_tv_vol_db_scale, -9600, 100, 0);
 127
 128 static struct snd_kcontrol_new snd_ivtv_mixer_tv_vol __initdata = {
 129         .iface = SNDRV_CTL_ELEM_IFACE_MIXER,
 130         .name = "Analog TV Capture Volume",
 131         .access = SNDRV_CTL_ELEM_ACCESS_READWRITE |
 132                   SNDRV_CTL_ELEM_ACCESS_TLV_READ,
 133         .info = snd_ivtv_mixer_tv_volume_info,
 134         .get = snd_ivtv_mixer_tv_volume_get,
 135         .put = snd_ivtv_mixer_tv_volume_put,
 136         .tlv.p = snd_ivtv_mixer_tv_vol_db_scale
 137 };
 138
 139 /* FIXME - add mute switch and balance, bass, treble sliders:
 140         V4L2_CID_AUDIO_MUTE
 141
 142         V4L2_CID_AUDIO_BALANCE
 143
 144         V4L2_CID_AUDIO_BASS
 145         V4L2_CID_AUDIO_TREBLE
 146 */
 147
 148 /* FIXME - add stereo, lang1, lang2, mono menu */
 149 /* FIXME - add I2S volume */
 150
 151 int __init snd_ivtv_mixer_create(struct snd_ivtv_card *itvsc)
 152 {
 153         struct v4l2_device *v4l2_dev = itvsc->v4l2_dev;
 154         struct snd_card *sc = itvsc->sc;
 155         int ret;
 156
 157         strlcpy(sc->mixername, "CX2341[56] Mixer", sizeof(sc->mixername));
 158
 159         ret = snd_ctl_add(sc, snd_ctl_new1(&snd_ivtv_mixer_tv_vol, itvsc));
 160         if (ret) {
 161                 IVTV_ALSA_WARN("%s: failed to add %s control, err %d\n",
 162                                __func__, snd_ivtv_mixer_tv_vol.name, ret);
 163         }
 164         return ret;
 165 }