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rockbox/firmware/drivers/audio/ak4376.c
Aidan MacDonald d93e054419 fiiom3k: power down amp before switching DAC power modes 
As detailed in the <Low Power Mode> section of the AK4376A
datasheet, the amp should be powered down before switching
power modes (or to a sample rate <= 12 KHz).

Change-Id: I3ab0a21c78a3ad2bb418b64c916f7dbe2a843efa
2022-01-16 19:35:40 -05:00

270 lines
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/***************************************************************************
* __________ __ ___.
* Open \______ \ ____ ____ | | _\_ |__ _______ ___
* Source | _// _ \_/ ___\| |/ /| __ \ / _ \ \/ /
* Jukebox | | ( <_> ) \___| < | \_\ ( <_> > < <
* Firmware |____|_ /\____/ \___ >__|_ \|___ /\____/__/\_ \
* \/ \/ \/ \/ \/
* $Id$
*
* Copyright (C) 2021 Aidan MacDonald
*
* 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 software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
* KIND, either express or implied.
*
****************************************************************************/
#include "audiohw.h"
#include "sound.h"
#include "panic.h"
#include "pcm_sampr.h"
#include "pcm_sw_volume.h"
#include "system.h"
#include "i2c-async.h"
/* sample rates supported by the hardware */
#define CAPS (SAMPR_CAP_192 | SAMPR_CAP_176 | \
SAMPR_CAP_96 | SAMPR_CAP_88 | SAMPR_CAP_64 | \
SAMPR_CAP_48 | SAMPR_CAP_44 | SAMPR_CAP_32 | \
SAMPR_CAP_24 | SAMPR_CAP_22 | SAMPR_CAP_16 | \
SAMPR_CAP_12 | SAMPR_CAP_11 | SAMPR_CAP_8)
/* future proofing */
#if (HW_SAMPR_CAPS & ~CAPS) != 0
# error "incorrect HW_SAMPR_CAPS"
#endif
#ifndef HAVE_SW_VOLUME_CONTROL
# error "AK4376 requires HAVE_SW_VOLUME_CONTROL!"
#endif
/* NOTE: At present, only the FiiO M3K uses this driver so the handling of
* the clock / audio interface is limited to I2S slave, 16-bit samples, with
* DAC master clock provided directly on the MCLK input pin, fitting the
* clock setup of the M3K.
*
* Feel free to expand upon this if another target ever needs this driver.
*/
/* Converts HW_FREQ_XX constants to register values */
static const uint8_t ak4376_fsel_to_hw[] = {
HW_HAVE_192_(AK4376_FS_192,)
HW_HAVE_176_(AK4376_FS_176,)
HW_HAVE_96_(AK4376_FS_96,)
HW_HAVE_88_(AK4376_FS_88,)
HW_HAVE_64_(AK4376_FS_64,)
HW_HAVE_48_(AK4376_FS_48,)
HW_HAVE_44_(AK4376_FS_44,)
HW_HAVE_32_(AK4376_FS_32,)
HW_HAVE_24_(AK4376_FS_24,)
HW_HAVE_22_(AK4376_FS_22,)
HW_HAVE_16_(AK4376_FS_16,)
HW_HAVE_12_(AK4376_FS_12,)
HW_HAVE_11_(AK4376_FS_11,)
HW_HAVE_8_(AK4376_FS_8,)
};
static int ak4376_regs[AK4376_NUM_REGS];
void ak4376_open(void)
{
/* Initialize DAC state */
for(int i = 0; i < AK4376_NUM_REGS; ++i)
ak4376_regs[i] = -1;
/* Initial reset after power-on */
ak4376_set_pdn_pin(0);
mdelay(1);
ak4376_set_pdn_pin(1);
mdelay(1);
static const uint8_t init_config[] = {
/* Ensure HPRHZ, HPLHZ are 0 */
AK4376_REG_OUTPUT_MODE, 0x00,
/* Mute all volume controls */
AK4376_REG_MIXER, AK4376_MIX_LCH | (AK4376_MIX_RCH << 4),
AK4376_REG_LCH_VOLUME, 0x80,
AK4376_REG_RCH_VOLUME, 0x00,
AK4376_REG_AMP_VOLUME, 0x00,
/* Clock source = MCLK, divider = 1 */
AK4376_REG_DAC_CLK_SRC, 0x00,
AK4376_REG_DAC_CLK_DIV, 0x00,
/* I2S slave mode, 16-bit samples */
AK4376_REG_AUDIO_IF_FMT, 0x03,
/* Recommended by datasheet */
AK4376_REG_ADJUST1, 0x20,
AK4376_REG_ADJUST2, 0x05,
/* Power controls */
AK4376_REG_PWR2, 0x33,
AK4376_REG_PWR3, 0x01,
AK4376_REG_PWR4, 0x03,
};
/* Write initial configuration prior to power-up */
for(size_t i = 0; i < ARRAYLEN(init_config); i += 2)
ak4376_write(init_config[i], init_config[i+1]);
}
void ak4376_close(void)
{
/* Shut off power */
ak4376_write(AK4376_REG_PWR3, 0x00);
ak4376_write(AK4376_REG_PWR4, 0x00);
ak4376_write(AK4376_REG_PWR2, 0x00);
/* PDN pin low */
ak4376_set_pdn_pin(0);
}
void ak4376_write(int reg, int value)
{
/* Ensure value is sensible and differs from the last set value */
if((value & 0xff) == value && ak4376_regs[reg] != value) {
int r = i2c_reg_write1(AK4376_BUS, AK4376_ADDR, reg, value);
if(r == I2C_STATUS_OK)
ak4376_regs[reg] = value;
else
ak4376_regs[reg] = -1;
}
}
int ak4376_read(int reg)
{
/* Only read from I2C if we don't already know the value */
if(ak4376_regs[reg] < 0)
ak4376_regs[reg] = i2c_reg_read1(AK4376_BUS, AK4376_ADDR, reg);
return ak4376_regs[reg];
}
static int round_step_up(int x, int step)
{
int rem = x % step;
if(rem > 0)
rem -= step;
return x - rem;
}
static void calc_volumes(int vol, int* dig, int* sw)
{
/* Apply digital volume */
*dig = round_step_up(vol, AK4376_DIG_VOLUME_STEP);
*dig = MIN(*dig, AK4376_DIG_VOLUME_MAX);
*dig = MAX(*dig, AK4376_DIG_VOLUME_MIN);
vol -= *dig;
/* Seems that this is the allowable range for software volume */
*sw = MIN(vol, 60);
*sw = MAX(*sw, -730);
vol -= *sw;
}
static int dig_vol_to_hw(int vol)
{
if(vol < AK4376_DIG_VOLUME_MIN) return 0;
if(vol > AK4376_DIG_VOLUME_MAX) return 31;
return (vol - AK4376_DIG_VOLUME_MIN) / AK4376_DIG_VOLUME_STEP + 1;
}
static int amp_vol_to_hw(int vol)
{
if(vol < AK4376_AMP_VOLUME_MIN) return 0;
if(vol > AK4376_AMP_VOLUME_MAX) return 14;
return (vol - AK4376_AMP_VOLUME_MIN) / AK4376_AMP_VOLUME_STEP + 1;
}
void ak4376_set_volume(int vol_l, int vol_r)
{
int amp;
int dig_l, sw_l;
int dig_r, sw_r;
if(vol_l <= AK4376_MIN_VOLUME && vol_r <= AK4376_MIN_VOLUME) {
/* Special case for full mute */
amp = AK4376_AMP_VOLUME_MUTE;
dig_l = dig_r = AK4376_DIG_VOLUME_MUTE;
sw_l = sw_r = PCM_MUTE_LEVEL;
} else {
/* Amp is a mono control -- calculate based on the loudest channel.
* The quieter channel then gets reduced more by digital controls. */
amp = round_step_up(MAX(vol_l, vol_r), AK4376_AMP_VOLUME_STEP);
amp = MIN(amp, AK4376_AMP_VOLUME_MAX);
amp = MAX(amp, AK4376_AMP_VOLUME_MIN);
/* Other controls are stereo */
calc_volumes(vol_l - amp, &dig_l, &sw_l);
calc_volumes(vol_r - amp, &dig_r, &sw_r);
}
ak4376_write(AK4376_REG_LCH_VOLUME, dig_vol_to_hw(dig_l) | (1 << 7));
ak4376_write(AK4376_REG_RCH_VOLUME, dig_vol_to_hw(dig_r));
ak4376_write(AK4376_REG_AMP_VOLUME, amp_vol_to_hw(amp));
pcm_set_master_volume(sw_l, sw_r);
}
void ak4376_set_filter_roll_off(int val)
{
int reg = ak4376_read(AK4376_REG_FILTER);
reg &= ~0xc0;
reg |= (val & 3) << 6;
ak4376_write(AK4376_REG_FILTER, reg);
}
void ak4376_set_freqmode(int fsel, int mult, int power_mode)
{
/* Calculate clock mode for frequency. Multipliers of 32/64 are only
* for rates >= 256 KHz which are not supported by Rockbox, so they
* are commented out -- but they're in the correct place. */
int clock_mode = ak4376_fsel_to_hw[fsel];
switch(mult) {
/* case 32: */
case 256:
break;
/* case 64: */
case 512:
clock_mode |= 0x20;
break;
case 1024:
clock_mode |= 0x40;
break;
case 128:
clock_mode |= 0x60;
break;
default:
panicf("ak4376: bad master clock multiple %d", mult);
return;
}
/* Handle the DSMLP bit in the MODE_CTRL register */
int mode_ctrl = 0x00;
if(power_mode == SOUND_LOW_POWER || hw_freq_sampr[fsel] <= SAMPR_12)
mode_ctrl |= 0x40;
/* Handle the LPMODE bit */
int pwr3 = power_mode == SOUND_LOW_POWER ? 0x11 : 0x01;
/* The datasheet says the HP amp must be powered down before changing
* the operating mode of the DAC or HP amp. I'm assuming this means
* the amp must be shut down when changing DSMLP or LPMODE. */
int cur_mode_ctrl = ak4376_read(AK4376_REG_MODE_CTRL);
int cur_pwr3 = ak4376_read(AK4376_REG_PWR3);
bool disable_amp = mode_ctrl != cur_mode_ctrl || pwr3 != cur_pwr3;
/* Program the new settings */
if(disable_amp)
ak4376_write(AK4376_REG_PWR4, 0x00);
ak4376_write(AK4376_REG_CLOCK_MODE, clock_mode);
ak4376_write(AK4376_REG_MODE_CTRL, mode_ctrl);
ak4376_write(AK4376_REG_PWR3, pwr3);
if(disable_amp) {
ak4376_write(AK4376_REG_PWR4, 0x03);
mdelay(26);
}
}
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