[PATCH 2/2] ASoC: codec: wm8960: Relax bit clock computation when using PLL
From: Daniel Baluta
Date: Tue Apr 04 2017 - 12:45:55 EST
Bitclk is derived from sysclk using bclk_divs.
Sysclk can be derived in two ways:
(1) directly from MLCK
(2) MCLK via PLL
Commit 3c01b9ee2ab9d0d ("ASoC: codec: wm8960: Relax bit clock computation")
relaxed bitclk computation when sysclk is directly derived from MCLK.
Lets do the same thing when sysclk is derived via PLL.
Signed-off-by: Daniel Baluta <daniel.baluta@xxxxxxx>
---
sound/soc/codecs/wm8960.c | 14 +++++++++++++-
1 file changed, 13 insertions(+), 1 deletion(-)
diff --git a/sound/soc/codecs/wm8960.c b/sound/soc/codecs/wm8960.c
index 36c8454..e8cb764 100644
--- a/sound/soc/codecs/wm8960.c
+++ b/sound/soc/codecs/wm8960.c
@@ -679,6 +679,10 @@ int wm8960_configure_sysclk(struct wm8960_priv *wm8960, int mclk,
* - freq_out = sysclk * sysclk_divs
* - 10 * sysclk = bclk * bclk_divs
*
+ * If we cannot find an exact match for (sysclk, lrclk, bclk)
+ * triplet, we relax the bclk such that bclk is chosen as the
+ * closest available frequency greater than expected bclk.
+ *
* @codec: codec structure
* @freq_in: input frequency used to derive freq out via PLL
* @sysclk_idx: sysclk_divs index for found sysclk
@@ -696,11 +700,12 @@ int wm8960_configure_pll(struct snd_soc_codec *codec, int freq_in,
{
struct wm8960_priv *wm8960 = snd_soc_codec_get_drvdata(codec);
int sysclk, bclk, lrclk, freq_out;
- int diff, best_freq_out;
+ int diff, closest, best_freq_out;
int i, j, k;
bclk = wm8960->bclk;
lrclk = wm8960->lrclk;
+ closest = freq_in;
*bclk_idx = -1;
@@ -723,6 +728,13 @@ int wm8960_configure_pll(struct snd_soc_codec *codec, int freq_in,
best_freq_out = freq_out;
break;
}
+ if (diff > 0 && closest > diff) {
+ *sysclk_idx = i;
+ *dac_idx = j;
+ *bclk_idx = k;
+ closest = diff;
+ best_freq_out = freq_out;
+ }
}
}
}
--
2.7.4