42750b04c5
This patch implements a TLV mechanism to transfer an additional information like dB scale to the user space. The types might be extended in future. Acked-by: Takashi Iwai <tiwai@suse.de> Signed-off-by: Jaroslav Kysela <perex@suse.cz>
44 lines
1.5 KiB
C
44 lines
1.5 KiB
C
#ifndef __SOUND_TLV_H
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#define __SOUND_TLV_H
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/*
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* Advanced Linux Sound Architecture - ALSA - Driver
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* Copyright (c) 2006 by Jaroslav Kysela <perex@suse.cz>
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*
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2 of the License, or
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* (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
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*
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*/
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/*
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* TLV structure is right behind the struct snd_ctl_tlv:
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* unsigned int type - see SNDRV_CTL_TLVT_*
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* unsigned int length
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* .... data aligned to sizeof(unsigned int), use
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* block_length = (length + (sizeof(unsigned int) - 1)) &
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* ~(sizeof(unsigned int) - 1)) ....
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*/
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#define SNDRV_CTL_TLVT_CONTAINER 0 /* one level down - group of TLVs */
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#define SNDRV_CTL_TLVT_DB_SCALE 1 /* dB scale */
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#define DECLARE_TLV_DB_SCALE(name, min, step, mute) \
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unsigned int name[] = { \
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SNDRV_CTL_TLVT_DB_SCALE, 2 * sizeof(unsigned int), \
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(min), ((step) & 0xffff) | ((mute) ? 0x10000 : 0) \
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}
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#endif /* __SOUND_TLV_H */
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