diff options
| author | Richard Fitzgerald <rf@opensource.wolfsonmicro.com> | 2016-04-21 14:04:14 +0100 |
|---|---|---|
| committer | Mark Brown <broonie@kernel.org> | 2016-04-21 16:58:38 +0100 |
| commit | 8e42db1eaab6c2558dbc2e6c1428730df0a295f4 (patch) | |
| tree | 7625993cf1061fa92fb315dcacc88108e425911b /sound/soc/codecs/arizona.c | |
| parent | 43b27d7286737d9af9ebeff0219e38560cb31748 (diff) | |
ASoC: arizona: Prefer lower FRATIO in pseudo-fractional mode
When setting up an FLL in pseudo-fractional mode it is preferred
to use a lower FRATIO if possible to give a higher reference clock
frequency. This patch swaps the two loops in arizona_calc_fratio()
so that lower FRATIOs are tried first. The decrementing loop is also
changed to start from init_ratio because the original settings might
already give a fractional value for N.K
Signed-off-by: Richard Fitzgerald <rf@opensource.wolfsonmicro.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
Diffstat (limited to 'sound/soc/codecs/arizona.c')
| -rw-r--r-- | sound/soc/codecs/arizona.c | 27 |
1 files changed, 15 insertions, 12 deletions
diff --git a/sound/soc/codecs/arizona.c b/sound/soc/codecs/arizona.c index d8a682302580..0caecc6f78df 100644 --- a/sound/soc/codecs/arizona.c +++ b/sound/soc/codecs/arizona.c @@ -2037,7 +2037,21 @@ static int arizona_calc_fratio(struct arizona_fll *fll, init_ratio, Fref, refdiv); while (div <= ARIZONA_FLL_MAX_REFDIV) { - for (ratio = init_ratio; ratio <= ARIZONA_FLL_MAX_FRATIO; + /* start from init_ratio because this may already give a + * fractional N.K + */ + for (ratio = init_ratio; ratio > 0; ratio--) { + if (target % (ratio * Fref)) { + cfg->refdiv = refdiv; + cfg->fratio = ratio - 1; + arizona_fll_dbg(fll, + "pseudo: found fref=%u refdiv=%d(%d) ratio=%d\n", + Fref, refdiv, div, ratio); + return ratio; + } + } + + for (ratio = init_ratio + 1; ratio <= ARIZONA_FLL_MAX_FRATIO; ratio++) { if ((ARIZONA_FLL_VCO_CORNER / 2) / (fll->vco_mult * ratio) < Fref) { @@ -2063,17 +2077,6 @@ static int arizona_calc_fratio(struct arizona_fll *fll, } } - for (ratio = init_ratio - 1; ratio > 0; ratio--) { - if (target % (ratio * Fref)) { - cfg->refdiv = refdiv; - cfg->fratio = ratio - 1; - arizona_fll_dbg(fll, - "pseudo: found fref=%u refdiv=%d(%d) ratio=%d\n", - Fref, refdiv, div, ratio); - return ratio; - } - } - div *= 2; Fref /= 2; refdiv++; |