tlv.h

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#ifndef __SOUND_TLV_H
#define __SOUND_TLV_H

/*
 *  Advanced Linux Sound Architecture - ALSA - Driver
 *  Copyright (c) 2006 by Jaroslav Kysela <[email protected]>
 *
 *
 *   This program is free software; you can redistribute it and/or modify
 *   it under the terms of the GNU General Public License as published by
 *   the Free Software Foundation; either version 2 of the License, or
 *   (at your option) any later version.
 *
 *   This program is distributed in the hope that it will be useful,
 *   but WITHOUT ANY WARRANTY; without even the implied warranty of
 *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *   GNU General Public License for more details.
 *
 *   You should have received a copy of the GNU General Public License
 *   along with this program; if not, write to the Free Software
 *   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
 *
 */

/*
 * TLV structure is right behind the struct snd_ctl_tlv:
 *   unsigned int type      - see SNDRV_CTL_TLVT_*
 *   unsigned int length
 *   .... data aligned to sizeof(unsigned int), use
 *        block_length = (length + (sizeof(unsigned int) - 1)) &
 *                       ~(sizeof(unsigned int) - 1)) ....
 */

#define SNDRV_CTL_TLVT_CONTAINER 0  /* one level down - group of TLVs */
#define SNDRV_CTL_TLVT_DB_SCALE 1       /* dB scale */
#define SNDRV_CTL_TLVT_DB_LINEAR 2  /* linear volume */
#define SNDRV_CTL_TLVT_DB_RANGE 3   /* dB range container */
#define SNDRV_CTL_TLVT_DB_MINMAX 4  /* dB scale with min/max */
#define SNDRV_CTL_TLVT_DB_MINMAX_MUTE 5 /* dB scale with min/max with mute */

#define TLV_ITEM(type, ...) \
    (type), TLV_LENGTH(__VA_ARGS__), __VA_ARGS__
#define TLV_LENGTH(...) \
    ((unsigned int)sizeof((const unsigned int[]) { __VA_ARGS__ }))

#define TLV_CONTAINER_ITEM(...) \
    TLV_ITEM(SNDRV_CTL_TLVT_CONTAINER, __VA_ARGS__)
#define DECLARE_TLV_CONTAINER(name, ...) \
    unsigned int name[] = { TLV_CONTAINER_ITEM(__VA_ARGS__) }

#define TLV_DB_SCALE_MASK   0xffff
#define TLV_DB_SCALE_MUTE   0x10000
#define TLV_DB_SCALE_ITEM(min, step, mute)          \
    TLV_ITEM(SNDRV_CTL_TLVT_DB_SCALE,           \
         (min),                 \
         ((step) & TLV_DB_SCALE_MASK) |     \
            ((mute) ? TLV_DB_SCALE_MUTE : 0))
#define DECLARE_TLV_DB_SCALE(name, min, step, mute) \
    unsigned int name[] = { TLV_DB_SCALE_ITEM(min, step, mute) }

/* dB scale specified with min/max values instead of step */
#define TLV_DB_MINMAX_ITEM(min_dB, max_dB)          \
    TLV_ITEM(SNDRV_CTL_TLVT_DB_MINMAX, (min_dB), (max_dB))
#define TLV_DB_MINMAX_MUTE_ITEM(min_dB, max_dB)         \
    TLV_ITEM(SNDRV_CTL_TLVT_DB_MINMAX_MUTE, (min_dB), (max_dB))
#define DECLARE_TLV_DB_MINMAX(name, min_dB, max_dB) \
    unsigned int name[] = { TLV_DB_MINMAX_ITEM(min_dB, max_dB) }
#define DECLARE_TLV_DB_MINMAX_MUTE(name, min_dB, max_dB) \
    unsigned int name[] = { TLV_DB_MINMAX_MUTE_ITEM(min_dB, max_dB) }

/* linear volume between min_dB and max_dB (.01dB unit) */
#define TLV_DB_LINEAR_ITEM(min_dB, max_dB)          \
    TLV_ITEM(SNDRV_CTL_TLVT_DB_LINEAR, (min_dB), (max_dB))
#define DECLARE_TLV_DB_LINEAR(name, min_dB, max_dB) \
    unsigned int name[] = { TLV_DB_LINEAR_ITEM(min_dB, max_dB) }

/* dB range container */
/* Each item is: <min> <max> <TLV> */
#define TLV_DB_RANGE_ITEM(...) \
    TLV_ITEM(SNDRV_CTL_TLVT_DB_RANGE, __VA_ARGS__)
#define DECLARE_TLV_DB_RANGE(name, ...) \
    unsigned int name[] = { TLV_DB_RANGE_ITEM(__VA_ARGS__) }
/* The below assumes that each item TLV is 4 words like DB_SCALE or LINEAR */
#define TLV_DB_RANGE_HEAD(num)          \
    SNDRV_CTL_TLVT_DB_RANGE, 6 * (num) * sizeof(unsigned int)

#define TLV_DB_GAIN_MUTE    -9999999

/*
 * channel-mapping TLV items
 *  TLV length must match with num_channels
 */
#define SNDRV_CTL_TLVT_CHMAP_FIXED  0x101   /* fixed channel position */
#define SNDRV_CTL_TLVT_CHMAP_VAR    0x102   /* channels freely swappable */
#define SNDRV_CTL_TLVT_CHMAP_PAIRED 0x103   /* pair-wise swappable */

#endif /* __SOUND_TLV_H */