[alsa-devel] [PATCH] ASoC: da7218: Update PLL ranges and dividers to improve locking

[Adam Thomson]

The expected MCLK frequency ranges and the associated dividers
are updated to improve PLL locking in a corner scenario, with low
MCLK frequency near an input divider change boundary.

Signed-off-by: Adam Thomson <Adam.Thomson.Opensource at diasemi.com>
---

This patch is based on v4.6-rc1 kernel version

 sound/soc/codecs/da7218.c | 32 ++++++++++++++++----------------
 sound/soc/codecs/da7218.h | 21 ++++++++++++---------
 2 files changed, 28 insertions(+), 25 deletions(-)

diff --git a/sound/soc/codecs/da7218.c b/sound/soc/codecs/da7218.c
index 93575f2..99ce23e 100644
--- a/sound/soc/codecs/da7218.c
+++ b/sound/soc/codecs/da7218.c
@@ -1868,27 +1868,27 @@ static int da7218_set_dai_pll(struct snd_soc_dai *codec_dai, int pll_id,
 
 	/* Verify 32KHz, 2MHz - 54MHz MCLK provided, and set input divider */
 	if (da7218->mclk_rate == 32768) {
-		indiv_bits = DA7218_PLL_INDIV_2_5_MHZ;
-		indiv = DA7218_PLL_INDIV_2_10_MHZ_VAL;
+		indiv_bits = DA7218_PLL_INDIV_9_TO_18_MHZ;
+		indiv = DA7218_PLL_INDIV_9_TO_18_MHZ_VAL;
 	} else if (da7218->mclk_rate < 2000000) {
 		dev_err(codec->dev, "PLL input clock %d below valid range\n",
 			da7218->mclk_rate);
 		return -EINVAL;
-	} else if (da7218->mclk_rate <= 5000000) {
-		indiv_bits = DA7218_PLL_INDIV_2_5_MHZ;
-		indiv = DA7218_PLL_INDIV_2_10_MHZ_VAL;
-	} else if (da7218->mclk_rate <= 10000000) {
-		indiv_bits = DA7218_PLL_INDIV_5_10_MHZ;
-		indiv = DA7218_PLL_INDIV_2_10_MHZ_VAL;
-	} else if (da7218->mclk_rate <= 20000000) {
-		indiv_bits = DA7218_PLL_INDIV_10_20_MHZ;
-		indiv = DA7218_PLL_INDIV_10_20_MHZ_VAL;
-	} else if (da7218->mclk_rate <= 40000000) {
-		indiv_bits = DA7218_PLL_INDIV_20_40_MHZ;
-		indiv = DA7218_PLL_INDIV_20_40_MHZ_VAL;
+	} else if (da7218->mclk_rate <= 4500000) {
+		indiv_bits = DA7218_PLL_INDIV_2_TO_4_5_MHZ;
+		indiv = DA7218_PLL_INDIV_2_TO_4_5_MHZ_VAL;
+	} else if (da7218->mclk_rate <= 9000000) {
+		indiv_bits = DA7218_PLL_INDIV_4_5_TO_9_MHZ;
+		indiv = DA7218_PLL_INDIV_4_5_TO_9_MHZ_VAL;
+	} else if (da7218->mclk_rate <= 18000000) {
+		indiv_bits = DA7218_PLL_INDIV_9_TO_18_MHZ;
+		indiv = DA7218_PLL_INDIV_9_TO_18_MHZ_VAL;
+	} else if (da7218->mclk_rate <= 36000000) {
+		indiv_bits = DA7218_PLL_INDIV_18_TO_36_MHZ;
+		indiv = DA7218_PLL_INDIV_18_TO_36_MHZ_VAL;
 	} else if (da7218->mclk_rate <= 54000000) {
-		indiv_bits = DA7218_PLL_INDIV_40_54_MHZ;
-		indiv = DA7218_PLL_INDIV_40_54_MHZ_VAL;
+		indiv_bits = DA7218_PLL_INDIV_36_TO_54_MHZ;
+		indiv = DA7218_PLL_INDIV_36_TO_54_MHZ_VAL;
 	} else {
 		dev_err(codec->dev, "PLL input clock %d above valid range\n",
 			da7218->mclk_rate);
diff --git a/sound/soc/codecs/da7218.h b/sound/soc/codecs/da7218.h
index c2c5904..477cd37 100644
--- a/sound/soc/codecs/da7218.h
+++ b/sound/soc/codecs/da7218.h
@@ -876,15 +876,11 @@
 /* DA7218_PLL_CTRL = 0x91 */
 #define DA7218_PLL_INDIV_SHIFT		0
 #define DA7218_PLL_INDIV_MASK		(0x7 << 0)
-#define DA7218_PLL_INDIV_2_5_MHZ	(0x0 << 0)
-#define DA7218_PLL_INDIV_5_10_MHZ	(0x1 << 0)
-#define DA7218_PLL_INDIV_10_20_MHZ	(0x2 << 0)
-#define DA7218_PLL_INDIV_20_40_MHZ	(0x3 << 0)
-#define DA7218_PLL_INDIV_40_54_MHZ	(0x4 << 0)
-#define DA7218_PLL_INDIV_2_10_MHZ_VAL	2
-#define DA7218_PLL_INDIV_10_20_MHZ_VAL	4
-#define DA7218_PLL_INDIV_20_40_MHZ_VAL	8
-#define DA7218_PLL_INDIV_40_54_MHZ_VAL	16
+#define DA7218_PLL_INDIV_2_TO_4_5_MHZ	(0x0 << 0)
+#define DA7218_PLL_INDIV_4_5_TO_9_MHZ	(0x1 << 0)
+#define DA7218_PLL_INDIV_9_TO_18_MHZ	(0x2 << 0)
+#define DA7218_PLL_INDIV_18_TO_36_MHZ	(0x3 << 0)
+#define DA7218_PLL_INDIV_36_TO_54_MHZ	(0x4 << 0)
 #define DA7218_PLL_MCLK_SQR_EN_SHIFT	4
 #define DA7218_PLL_MCLK_SQR_EN_MASK	(0x1 << 4)
 #define DA7218_PLL_MODE_SHIFT		6
@@ -1336,6 +1332,13 @@
 #define DA7218_PLL_FREQ_OUT_90316	90316800
 #define DA7218_PLL_FREQ_OUT_98304	98304000
 
+/* PLL Frequency Dividers */
+#define DA7218_PLL_INDIV_2_TO_4_5_MHZ_VAL	1
+#define DA7218_PLL_INDIV_4_5_TO_9_MHZ_VAL	2
+#define DA7218_PLL_INDIV_9_TO_18_MHZ_VAL	4
+#define DA7218_PLL_INDIV_18_TO_36_MHZ_VAL	8
+#define DA7218_PLL_INDIV_36_TO_54_MHZ_VAL	16
+
 /* ALC Calibration */
 #define DA7218_ALC_CALIB_DELAY_MIN	2500
 #define DA7218_ALC_CALIB_DELAY_MAX	5000
-- 
1.9.3