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Implement universal in-PCM-driver software volume control.

Browse source 
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>
This commit is contained in:
Michael Sevakis 2013-04-05 04:36:05 -04:00
parent a9049a79d7
commit f5a5b94686
13 changed files with 478 additions and 156 deletions
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27
firmware/target/mips/ingenic_jz47xx/codec-jz4740.c
View file

@ -24,11 +24,12 @@
#include "sound.h"
#include "jz4740.h"
#include "system.h"
#include "pcm_sw_volume.h"
/* TODO */
const struct sound_settings_info audiohw_settings[] = {
#ifdef HAVE_SW_VOLUME_CONTROL
[SOUND_VOLUME] = {"dB", 0, 1, SW_VOLUME_MIN, 6, 0},
[SOUND_VOLUME] = {"dB", 0, 1, -74, 6, -25},
#else
[SOUND_VOLUME] = {"dB", 0, 1, 0, 6, 0},
#endif
@ -293,16 +294,24 @@ void audiohw_init(void)
i2s_codec_init();
}
void audiohw_set_volume(int v)
void audiohw_set_master_vol(int vol_l, int vol_r)
{
if(v >= 0)
{
/* 0 <= v <= 60 */
unsigned int codec_volume = ICDC_CDCCR2_HPVOL(v / 20);
#ifdef HAVE_SW_VOLUME_CONTROL
/* SW volume for <= 1.0 gain, HW at unity, < VOLUME_MIN == MUTE */
int sw_volume_l = vol_l < VOLUME_MIN ? PCM_MUTE_LEVEL : MIN(vol_l, 0);
int sw_volume_r = vol_r < VOLUME_MIN ? PCM_MUTE_LEVEL : MIN(vol_r, 0);
pcm_set_master_volume(sw_volume_l, sw_volume_r);
#endif /* HAVE_SW_VOLUME_CONTROL */
if((REG_ICDC_CDCCR2 & ICDC_CDCCR2_HPVOL(0x3)) != codec_volume)
REG_ICDC_CDCCR2 = (REG_ICDC_CDCCR2 & ~ICDC_CDCCR2_HPVOL(0x3)) | codec_volume;
}
/* NOTE: the channel being cut if balance is not equal will need
adjusting downward so maintain proportion if using volume boost */
/* HW volume for > 1.0 gain */
int v = MAX(vol_l, vol_r);
unsigned int hw_volume = v > 0 ? ICDC_CDCCR2_HPVOL(v / 20) : 0;
if((REG_ICDC_CDCCR2 & ICDC_CDCCR2_HPVOL(0x3)) != hw_volume)
REG_ICDC_CDCCR2 = (REG_ICDC_CDCCR2 & ~ICDC_CDCCR2_HPVOL(0x3)) | hw_volume;
}
void audiohw_set_frequency(int freq)