ASoC: arizona: Optimise FLL loop gains

For optimal performance the FLL loop gain should be adjusted depending on
the frequency of the input clock for the loop.

Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
This commit is contained in:
Mark Brown 2013-03-05 12:08:57 +08:00
parent 576411be20
commit 8f113d7d26

View file

@ -990,6 +990,16 @@ static struct {
{ 1000000, 13500000, 0, 1 },
};
static struct {
unsigned int min;
unsigned int max;
u16 gain;
} fll_gains[] = {
{ 0, 256000, 0 },
{ 256000, 1000000, 2 },
{ 1000000, 13500000, 4 },
};
struct arizona_fll_cfg {
int n;
int theta;
@ -997,6 +1007,7 @@ struct arizona_fll_cfg {
int refdiv;
int outdiv;
int fratio;
int gain;
};
static int arizona_calc_fll(struct arizona_fll *fll,
@ -1056,6 +1067,18 @@ static int arizona_calc_fll(struct arizona_fll *fll,
return -EINVAL;
}
for (i = 0; i < ARRAY_SIZE(fll_gains); i++) {
if (fll_gains[i].min <= Fref && Fref <= fll_gains[i].max) {
cfg->gain = fll_gains[i].gain;
break;
}
}
if (i == ARRAY_SIZE(fll_gains)) {
arizona_fll_err(fll, "Unable to find gain for Fref=%uHz\n",
Fref);
return -EINVAL;
}
cfg->n = target / (ratio * Fref);
if (target % (ratio * Fref)) {
@ -1083,13 +1106,15 @@ static int arizona_calc_fll(struct arizona_fll *fll,
cfg->n, cfg->theta, cfg->lambda);
arizona_fll_dbg(fll, "FRATIO=%x(%d) OUTDIV=%x REFCLK_DIV=%x\n",
cfg->fratio, cfg->fratio, cfg->outdiv, cfg->refdiv);
arizona_fll_dbg(fll, "GAIN=%d\n", cfg->gain);
return 0;
}
static void arizona_apply_fll(struct arizona *arizona, unsigned int base,
struct arizona_fll_cfg *cfg, int source)
struct arizona_fll_cfg *cfg, int source,
bool sync)
{
regmap_update_bits(arizona->regmap, base + 3,
ARIZONA_FLL1_THETA_MASK, cfg->theta);
@ -1104,6 +1129,15 @@ static void arizona_apply_fll(struct arizona *arizona, unsigned int base,
cfg->refdiv << ARIZONA_FLL1_CLK_REF_DIV_SHIFT |
source << ARIZONA_FLL1_CLK_REF_SRC_SHIFT);
if (sync)
regmap_update_bits(arizona->regmap, base + 0x7,
ARIZONA_FLL1_GAIN_MASK,
cfg->gain << ARIZONA_FLL1_GAIN_SHIFT);
else
regmap_update_bits(arizona->regmap, base + 0x9,
ARIZONA_FLL1_GAIN_MASK,
cfg->gain << ARIZONA_FLL1_GAIN_SHIFT);
regmap_update_bits(arizona->regmap, base + 2,
ARIZONA_FLL1_CTRL_UPD | ARIZONA_FLL1_N_MASK,
ARIZONA_FLL1_CTRL_UPD | cfg->n);
@ -1141,17 +1175,18 @@ static void arizona_enable_fll(struct arizona_fll *fll,
ARIZONA_FLL1_OUTDIV_MASK,
ref->outdiv << ARIZONA_FLL1_OUTDIV_SHIFT);
arizona_apply_fll(arizona, fll->base, ref, fll->ref_src);
arizona_apply_fll(arizona, fll->base, ref, fll->ref_src,
false);
if (fll->sync_src >= 0)
arizona_apply_fll(arizona, fll->base + 0x10, sync,
fll->sync_src);
fll->sync_src, true);
} else if (fll->sync_src >= 0) {
regmap_update_bits(arizona->regmap, fll->base + 5,
ARIZONA_FLL1_OUTDIV_MASK,
sync->outdiv << ARIZONA_FLL1_OUTDIV_SHIFT);
arizona_apply_fll(arizona, fll->base, sync,
fll->sync_src);
fll->sync_src, false);
} else {
arizona_fll_err(fll, "No clocks provided\n");
return;