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[6/7] ASoC: fsl_sai: use DIV_ROUND_CLOSEST() to calculate divider

Message ID 20220302083428.3804687-7-s.hauer@pengutronix.de
State Accepted
Commit 1d4cbdf7bf2eaa794528250a29aed08f1df7f837
Headers show
Series ASoC: fsl_sai: Cleanups and 1:1 bclk:mclk ratio support | expand

Commit Message

Sascha Hauer March 2, 2022, 8:34 a.m. UTC 
In fsl_sai_set_bclk() we want to calculate the divider that gets us
closest to the desired frequency, so use DIV_ROUND_CLOSEST() instead of
just doing a clk_rate/freq.
Also discard invalid ratios earlier.

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
---
 sound/soc/fsl/fsl_sai.c | 12 +++++-------
 1 file changed, 5 insertions(+), 7 deletions(-)
diff mbox series

Patch

diff --git a/sound/soc/fsl/fsl_sai.c b/sound/soc/fsl/fsl_sai.c
index 190f6206023fa..818bb982427f8 100644
--- a/sound/soc/fsl/fsl_sai.c
+++ b/sound/soc/fsl/fsl_sai.c
@@ -366,9 +366,11 @@  static int fsl_sai_set_bclk(struct snd_soc_dai *dai, bool tx, u32 freq)
 		if (!clk_rate)
 			continue;
 
-		ratio = clk_rate / freq;
+		ratio = DIV_ROUND_CLOSEST(clk_rate, freq);
+		if (!ratio || ratio > 512 || ratio & 1)
+			continue;
 
-		diff = clk_rate - ratio * freq;
+		diff = abs((long)clk_rate - ratio * freq);
 
 		/*
 		 * Drop the source that can not be
@@ -381,10 +383,6 @@  static int fsl_sai_set_bclk(struct snd_soc_dai *dai, bool tx, u32 freq)
 			"ratio %d for freq %dHz based on clock %ldHz\n",
 			ratio, freq, clk_rate);
 
-		if (ratio % 2 == 0 && ratio >= 2 && ratio <= 512)
-			ratio /= 2;
-		else
-			continue;
 
 		if (diff < bestdiff) {
 			savediv = ratio;
@@ -424,7 +422,7 @@  static int fsl_sai_set_bclk(struct snd_soc_dai *dai, bool tx, u32 freq)
 
 	regmap_update_bits(sai->regmap, reg, FSL_SAI_CR2_MSEL_MASK,
 			   FSL_SAI_CR2_MSEL(sai->mclk_id[tx]));
-	regmap_update_bits(sai->regmap, reg, FSL_SAI_CR2_DIV_MASK, savediv - 1);
+	regmap_update_bits(sai->regmap, reg, FSL_SAI_CR2_DIV_MASK, savediv / 2 - 1);
 
 	return 0;
 }