f5a5b94686
Implements double-buffered volume, balance and prescaling control in the main PCM driver when HAVE_SW_VOLUME_CONTROL is defined ensuring that all PCM is volume controlled and level changes are low in latency. Supports -73 to +6 dB using a 15-bit factor so that no large-integer math is needed. Low-level hardware drivers do not have to implement it themselves but parameters can be changed (currently defined in pcm-internal.h) to work best with a particular SoC or to provide different volume ranges. Volume and prescale calls should be made in the codec driver. It should appear as a normal hardware interface. PCM volume calls expect .1 dB units. Change-Id: Idf6316a64ef4fb8abcede10707e1e6c6d01d57db Reviewed-on: http://gerrit.rockbox.org/423 Reviewed-by: Michael Sevakis <jethead71@rockbox.org> Tested-by: Michael Sevakis <jethead71@rockbox.org>
37 lines
1.3 KiB
C
37 lines
1.3 KiB
C
/***************************************************************************
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* __________ __ ___.
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* Open \______ \ ____ ____ | | _\_ |__ _______ ___
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* Source | _// _ \_/ ___\| |/ /| __ \ / _ \ \/ /
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* Jukebox | | ( <_> ) \___| < | \_\ ( <_> > < <
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* Firmware |____|_ /\____/ \___ >__|_ \|___ /\____/__/\_ \
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* \/ \/ \/ \/ \/
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* $Id$
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*
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* Copyright (C) 2012 Michael Sevakis
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License
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* as published by the Free Software Foundation; either version 2
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* of the License, or (at your option) any later version.
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*
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* This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
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* KIND, either express or implied.
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*
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****************************************************************************/
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#ifndef PGA_H
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#define PGA_H
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#define PGA_UNITY ((int32_t)0x01000000) /* s7.24 */
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/* Various gains supported by pre-gain amp */
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enum pga_gain_ids
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{
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PGA_EQ_PRECUT = 0,
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PGA_REPLAYGAIN,
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PGA_NUM_GAINS,
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};
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void pga_set_gain(enum pga_gain_ids id, int32_t value);
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void pga_enable_gain(enum pga_gain_ids id, bool enable);
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#endif /* PGA_H */
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