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  *  You should have received a copy of the GNU General Public License
  18  *  along with this program; if not, write to the Free Software
  19  *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
  20  *  02111-1307  USA
  21  */
  22
  23 #include <linux/init.h>
  24 #include <linux/kernel.h>
  25 #include <linux/device.h>
  26 #include <linux/spinlock.h>
  27 #include <linux/videodev2.h>
  28
  29 #include <media/v4l2-device.h>
  30
  31 #include <sound/core.h>
  32 #include <sound/control.h>
  33 #include <sound/tlv.h>
  34
  35 #include "ivtv-alsa.h"
  36 #include "ivtv-driver.h"
  37
  38 /*
  39  * Note the cx25840-core volume scale is funny, due to the alignment of the
  40  * scale with another chip's range:
  41  *
  42  * v4l2_control value   /512    indicated dB    actual dB       reg 0x8d4
  43  * 0x0000 - 0x01ff        0     -119            -96             228
  44  * 0x0200 - 0x02ff        1     -118            -96             228
  45  * ...
  46  * 0x2c00 - 0x2dff       22      -97            -96             228
  47  * 0x2e00 - 0x2fff       23      -96            -96             228
  48  * 0x3000 - 0x31ff       24      -95            -95             226
  49  * ...
  50  * 0xee00 - 0xefff      119        0              0              36
  51  * ...
  52  * 0xfe00 - 0xffff      127       +8             +8              20
  53  */
  54 static inline int dB_to_cx25840_vol(int dB)
  55 {
  56         if (dB < -96)
  57                 dB = -96;
  58         else if (dB > 8)
  59                 dB = 8;
  60         return (dB + 119) << 9;
  61 }
  62
  63 static inline int cx25840_vol_to_dB(int v)
  64 {
  65         if (v < (23 << 9))
  66                 v = (23 << 9);
  67         else if (v > (127 << 9))
  68                 v = (127 << 9);
  69         return (v >> 9) - 119;
  70 }
  71
  72 static int snd_ivtv_mixer_tv_vol_info(struct snd_kcontrol *kcontrol,
  73                                       struct snd_ctl_elem_info *uinfo)
  74 {
  75         uinfo->type = SNDRV_CTL_ELEM_TYPE_INTEGER;
  76         uinfo->count = 1;
  77         /* We're already translating values, just keep this control in dB */
  78         uinfo->value.integer.min  = -96;
  79         uinfo->value.integer.max  =   8;
  80         uinfo->value.integer.step =   1;
  81         return 0;
  82 }
  83
  84 static int snd_ivtv_mixer_tv_vol_get(struct snd_kcontrol *kctl,
  85                                      struct snd_ctl_elem_value *uctl)
  86 {
  87         struct snd_ivtv_card *itvsc = snd_kcontrol_chip(kctl);
  88         struct ivtv *itv = to_ivtv(itvsc->v4l2_dev);
  89         struct v4l2_control vctrl;
  90         int ret;
  91
  92         vctrl.id = V4L2_CID_AUDIO_VOLUME;
  93         vctrl.value = dB_to_cx25840_vol(uctl->value.integer.value[0]);
  94
  95         snd_ivtv_lock(itvsc);
  96         ret = v4l2_g_ctrl(itv->sd_audio->ctrl_handler, &vctrl);
  97         snd_ivtv_unlock(itvsc);
  98
  99         if (!ret)
 100                 uctl->value.integer.value[0] = cx25840_vol_to_dB(vctrl.value);
 101         return ret;
 102 }
 103
 104 static int snd_ivtv_mixer_tv_vol_put(struct snd_kcontrol *kctl,
 105                                      struct snd_ctl_elem_value *uctl)
 106 {
 107         struct snd_ivtv_card *itvsc = snd_kcontrol_chip(kctl);
 108         struct ivtv *itv = to_ivtv(itvsc->v4l2_dev);
 109         struct v4l2_control vctrl;
 110         int ret;
 111
 112         vctrl.id = V4L2_CID_AUDIO_VOLUME;
 113         vctrl.value = dB_to_cx25840_vol(uctl->value.integer.value[0]);
 114
 115         snd_ivtv_lock(itvsc);
 116
 117         /* Fetch current state */
 118         ret = v4l2_g_ctrl(itv->sd_audio->ctrl_handler, &vctrl);
 119
 120         if (ret ||
 121             (cx25840_vol_to_dB(vctrl.value) != uctl->value.integer.value[0])) {
 122
 123                 /* Set, if needed */
 124                 vctrl.value = dB_to_cx25840_vol(uctl->value.integer.value[0]);
 125                 ret = v4l2_s_ctrl(itv->sd_audio->ctrl_handler, &vctrl);
 126                 if (!ret)
 127                         ret = 1; /* Indicate control was changed w/o error */
 128         }
 129         snd_ivtv_unlock(itvsc);
 130
 131         return ret;
 132 }
 133
 134
 135 /* This is a bit of overkill, the slider is already in dB internally */
 136 static DECLARE_TLV_DB_SCALE(snd_ivtv_mixer_tv_vol_db_scale, -9600, 100, 0);
 137
 138 static struct snd_kcontrol_new snd_ivtv_mixer_tv_vol __initdata = {
 139         .iface = SNDRV_CTL_ELEM_IFACE_MIXER,
 140         .name = "Analog TV Capture Volume",
 141         .access = SNDRV_CTL_ELEM_ACCESS_READWRITE |
 142                   SNDRV_CTL_ELEM_ACCESS_TLV_READ,
 143         .info = snd_ivtv_mixer_tv_volume_info,
 144         .get = snd_ivtv_mixer_tv_volume_get,
 145         .put = snd_ivtv_mixer_tv_volume_put,
 146         .tlv.p = snd_ivtv_mixer_tv_vol_db_scale
 147 };
 148
 149 /* FIXME - add mute switch and balance, bass, treble sliders:
 150         V4L2_CID_AUDIO_MUTE
 151
 152         V4L2_CID_AUDIO_BALANCE
 153
 154         V4L2_CID_AUDIO_BASS
 155         V4L2_CID_AUDIO_TREBLE
 156 */
 157
 158 /* FIXME - add stereo, lang1, lang2, mono menu */
 159 /* FIXME - add I2S volume */
 160
 161 int __init snd_ivtv_mixer_create(struct snd_ivtv_card *itvsc)
 162 {
 163         struct v4l2_device *v4l2_dev = itvsc->v4l2_dev;
 164         struct snd_card *sc = itvsc->sc;
 165         int ret;
 166
 167         strlcpy(sc->mixername, "CX2341[56] Mixer", sizeof(sc->mixername));
 168
 169         ret = snd_ctl_add(sc, snd_ctl_new1(snd_ivtv_mixer_tv_vol, itvsc));
 170         if (ret) {
 171                 IVTV_ALSA_WARN("%s: failed to add %s control, err %d\n",
 172                                __func__, snd_ivtv_mixer_tv_vol.name, ret);
 173         }
 174         return ret;
 175 }