[PATCH v2] ASoC: wm8962: Relax bit clock divider searching

[Shengjiu Wang]

With S20_3LE format case, the sysclk = rate * 384,
the bclk = rate * 20 * 2, there is no proper bclk divider
for 384 / 40, because current condition needs exact match.
So driver fails to configure the clocking:

wm8962 3-001a: Unsupported BCLK ratio 9

Fix this by relaxing bitclk divider searching, so that when
no exact value can be derived from sysclk pick the closest
value greater than expected bitclk.

Signed-off-by: Shengjiu Wang <shengjiu.w...@nxp.com>
Reviewed-by: Daniel Baluta <daniel.bal...@nxp.com>
---
changes in v2:
- Add debug message according to Charles's comments

 sound/soc/codecs/wm8962.c | 23 +++++++++++++----------
 1 file changed, 13 insertions(+), 10 deletions(-)

diff --git a/sound/soc/codecs/wm8962.c b/sound/soc/codecs/wm8962.c
index ce4666a74793..34080f497584 100644
--- a/sound/soc/codecs/wm8962.c
+++ b/sound/soc/codecs/wm8962.c
@@ -2403,6 +2403,7 @@ static const int sysclk_rates[] = {
 static void wm8962_configure_bclk(struct snd_soc_component *component)
 {
        struct wm8962_priv *wm8962 = snd_soc_component_get_drvdata(component);
+       int best, min_diff, diff;
        int dspclk, i;
        int clocking2 = 0;
        int clocking4 = 0;
@@ -2473,23 +2474,25 @@ static void wm8962_configure_bclk(struct 
snd_soc_component *component)
 
        dev_dbg(component->dev, "DSPCLK is %dHz, BCLK %d\n", dspclk, 
wm8962->bclk);
 
-       /* We're expecting an exact match */
+       /* Search a proper bclk, not exact match. */
+       best = 0;
+       min_diff = INT_MAX;
        for (i = 0; i < ARRAY_SIZE(bclk_divs); i++) {
                if (bclk_divs[i] < 0)
                        continue;
 
-               if (dspclk / bclk_divs[i] == wm8962->bclk) {
-                       dev_dbg(component->dev, "Selected BCLK_DIV %d for 
%dHz\n",
-                               bclk_divs[i], wm8962->bclk);
-                       clocking2 |= i;
+               diff = (dspclk / bclk_divs[i]) - wm8962->bclk;
+               if (diff < 0) /* Table is sorted */
                        break;
+               if (diff < min_diff) {
+                       best = i;
+                       min_diff = diff;
                }
        }
-       if (i == ARRAY_SIZE(bclk_divs)) {
-               dev_err(component->dev, "Unsupported BCLK ratio %d\n",
-                       dspclk / wm8962->bclk);
-               return;
-       }
+       wm8962->bclk = dspclk / bclk_divs[best];
+       clocking2 |= best;
+       dev_dbg(component->dev, "Selected BCLK_DIV %d for %dHz\n",
+               bclk_divs[best], wm8962->bclk);
 
        aif2 |= wm8962->bclk / wm8962->lrclk;
        dev_dbg(component->dev, "Selected LRCLK divisor %d for %dHz\n",
-- 
2.27.0