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jz4760: Major clocking improvements for audio PLL

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* for <= 48KHz, BCLK must be 256*freq  (ie bdiv = 4)
 * for <= 96KHz, BCLK must be 128*freq  (ie bdiv = 2)
 * for 11/22/44/88 KHz, disable PLL1 and run off XTAL
 * cut PLL1 with 12/24/48/98 KHz audio from 516->86MHz
 * cut PLL1 with 8/16/32/64 KHz audio from 426->106.5MHz

This should result in significant power savings for
common 44.1KHz audio playback, and pretty good savings
for everything else.

As an added bonus:

 * enable de-emphasis filters at 32, 44.1, and 48 KHz

Change-Id: Ie59067cd46c47e62abf4a32c53519efad104d6c8
This commit is contained in:
Solomon Peachy 2020-08-07 08:04:19 -04:00
parent eb0e41c1cc
commit b3a0187416
1 changed files with 55 additions and 37 deletions
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92
firmware/target/mips/ingenic_jz47xx/codec-jz4760.c
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@ -87,10 +87,10 @@ void audiohw_preinit(void)
void audiohw_init(void)
{
__gpio_as_func1(3*32+12); // BCK
__gpio_as_func0(3*32+13); // LRCK
__gpio_as_func2(4*32+5); // MCLK
__gpio_as_func0(4*32+7); // DO
__gpio_as_func1(3*32+12); // BCK - BCLK pin AA20 func 1
__gpio_as_func0(3*32+13); // LRCK - SYNC pin W19 func 0
__gpio_as_func2(4*32+5); // MCLK - SCLK_RSTN - E20 fund 2
__gpio_as_func0(4*32+7); // DO - SDATO pin Y19 func 0
pop_ctrl(0);
ap_mute(true);
@ -194,85 +194,96 @@ void audiohw_set_filter_roll_off(int value)
void pll1_init(unsigned int freq);
void pll1_disable(void);
#if CFG_EXTAL != 12000000
#error "non-12MHz XTAL needs new audio rates calculated!"
#endif
void audiohw_set_frequency(int fsel)
{
unsigned int pll1_speed;
unsigned short mclk_div, bclk_div, func_mode;
unsigned char dem = CS4398_DEM_NONE;
// bclk is 1..8
// bclk is 2,3,4,6,8,12 ONLY
// mclk is 1..512
// for cs4398, BCLK must be 4 for single-rate, 2 for double-rate, 1 for quad-rate!
// 11.025 and 22.050 are a little wonky.
switch(fsel)
{
case HW_FREQ_8: // 0.512 MHz
pll1_speed = 426000000;
mclk_div = 52;
bclk_div = 16;
pll1_speed = 426000000/4;
mclk_div = 208/4;
bclk_div = 4;
func_mode = 0;
break;
case HW_FREQ_11: // 0.7056 MHz
pll1_speed = 508000000;
mclk_div = 45;
bclk_div = 16;
pll1_speed = 0;
mclk_div = 272;
bclk_div = 4;
func_mode = 0;
break;
case HW_FREQ_12: // 0.768 MHz
pll1_speed = 516000000;
mclk_div = 42;
bclk_div = 16;
pll1_speed = 516000000/2/3;
mclk_div = 168/2/3;
bclk_div = 4;
func_mode = 0;
break;
case HW_FREQ_16: // 1.024 MHz
pll1_speed = 426000000;
mclk_div = 52;
bclk_div = 8;
pll1_speed = 426000000/4;
mclk_div = 104/4;
bclk_div = 4;
func_mode = 0;
break;
case HW_FREQ_22: // 1.4112 MHz
pll1_speed = 508000000;
mclk_div = 45;
bclk_div = 8;
pll1_speed = 0;
mclk_div = 136;
bclk_div = 4;
func_mode = 0;
break;
case HW_FREQ_24: // 1.536 MHz
pll1_speed = 516000000;
mclk_div = 42;
bclk_div = 8;
pll1_speed = 516000000/2/3;
mclk_div = 84/2/3;
bclk_div = 4;
func_mode = 0;
break;
case HW_FREQ_32: // 2.048 MHz
pll1_speed = 426000000;
mclk_div = 52;
pll1_speed = 426000000/4;
mclk_div = 52/4;
bclk_div = 4;
dem = CS4398_DEM_32000;
func_mode = 0;
break;
case HW_FREQ_44: // 2.8224 MHz
pll1_speed = 508000000;
mclk_div = 45;
pll1_speed = 0;
mclk_div = 68;
bclk_div = 4;
dem = CS4398_DEM_44100;
func_mode = 0;
break;
case HW_FREQ_48: // 3.072 MHz
pll1_speed = 516000000;
mclk_div = 42;
pll1_speed = 516000000/2/3;
mclk_div = 42/2/3;
bclk_div = 4;
dem = CS4398_DEM_48000;
func_mode = 0;
break;
case HW_FREQ_64: // 4.096 MHz
pll1_speed = 426000000;
mclk_div = 52;
pll1_speed = 426000000/4;
mclk_div = 52/4;
bclk_div = 2;
func_mode = 1;
break;
case HW_FREQ_88: // 5.6448 MHz
pll1_speed = 508000000;
mclk_div = 45;
pll1_speed = 0;
mclk_div = 68;
bclk_div = 2;
func_mode = 1;
break;
case HW_FREQ_96: // 6.144 MHz
pll1_speed = 516000000;
mclk_div = 42;
pll1_speed = 516000000/2/3;
mclk_div = 42/2/3;
bclk_div = 2;
func_mode = 1;
break;
@ -286,13 +297,20 @@ void audiohw_set_frequency(int fsel)
/* 0 = Single-Speed Mode (<50KHz);
1 = Double-Speed Mode (50-100KHz);
2 = Quad-Speed Mode; (100-200KHz) */
cs4398_write_reg(CS4398_REG_MODECTL, (cs4398_read_reg(CS4398_REG_MODECTL) & ~CS4398_FM_MASK) | func_mode);
cs4398_write_reg(CS4398_REG_MODECTL, (cs4398_read_reg(CS4398_REG_MODECTL) & ~(CS4398_FM_MASK|CS4398_DEM_MASK)) | func_mode | dem);
if (func_mode == 2)
cs4398_write_reg(CS4398_REG_MISC, cs4398_read_reg(CS4398_REG_MISC) | CS4398_MCLKDIV2);
else
cs4398_write_reg(CS4398_REG_MISC, cs4398_read_reg(CS4398_REG_MISC) & ~CS4398_MCLKDIV2);
pll1_init(pll1_speed);
if (pll1_speed == 0) {
pll1_disable();
__cpm_select_i2sclk_exclk();
} else {
__cpm_select_i2sclk_pll();
__cpm_select_i2sclk_pll1();
pll1_init(pll1_speed);
}
__cpm_enable_pll_change();
__cpm_set_i2sdiv(mclk_div-1);
__i2s_set_i2sdiv(bclk_div-1);