ASoC: cs42l42: Fix 1536000 Bit Clock instability

The 16 Bits, 2 channels, 48K sample rate use case needs
to configure a safer pll_divout during the start of PLL
After 800us from the start of PLL the correct pll_divout
can be set
Signed-off-by: Lucas Tanure <tanureal@opensource.cirrus.com>
Reviewed-by: Richard Fitzgerald <rf@opensource.cirrus.com>
Message-Id: <20210525090822.64577-1-tanureal@opensource.cirrus.com>
Signed-off-by: Mark Brown <broonie@sirena.org.uk>

sound/soc/codecs/cs42l42.c

@@ -589,6 +589,7 @@ struct cs42l42_pll_params {
 	u8 pll_divout;
 	u32 mclk_int;
 	u8 pll_cal_ratio;
+	u8 n;
 };
 
 /*
@@ -596,21 +597,21 @@ struct cs42l42_pll_params {
  * Table 4-5 from the Datasheet
  */
 static const struct cs42l42_pll_params pll_ratio_table[] = {
-	{ 1536000, 0, 1, 0x00, 0x7D, 0x000000, 0x03, 0x10, 12000000, 125 },
-	{ 2822400, 0, 1, 0x00, 0x40, 0x000000, 0x03, 0x10, 11289600, 128 },
-	{ 3000000, 0, 1, 0x00, 0x40, 0x000000, 0x03, 0x10, 12000000, 128 },
-	{ 3072000, 0, 1, 0x00, 0x3E, 0x800000, 0x03, 0x10, 12000000, 125 },
-	{ 4000000, 0, 1, 0x00, 0x30, 0x800000, 0x03, 0x10, 12000000, 96 },
-	{ 4096000, 0, 1, 0x00, 0x2E, 0xE00000, 0x03, 0x10, 12000000, 94 },
-	{ 5644800, 0, 1, 0x01, 0x40, 0x000000, 0x03, 0x10, 11289600, 128 },
-	{ 6000000, 0, 1, 0x01, 0x40, 0x000000, 0x03, 0x10, 12000000, 128 },
-	{ 6144000, 0, 1, 0x01, 0x3E, 0x800000, 0x03, 0x10, 12000000, 125 },
-	{ 11289600, 0, 0, 0, 0, 0, 0, 0, 11289600, 0 },
-	{ 12000000, 0, 0, 0, 0, 0, 0, 0, 12000000, 0 },
-	{ 12288000, 0, 0, 0, 0, 0, 0, 0, 12288000, 0 },
-	{ 22579200, 1, 0, 0, 0, 0, 0, 0, 22579200, 0 },
-	{ 24000000, 1, 0, 0, 0, 0, 0, 0, 24000000, 0 },
-	{ 24576000, 1, 0, 0, 0, 0, 0, 0, 24576000, 0 }
+	{ 1536000, 0, 1, 0x00, 0x7D, 0x000000, 0x03, 0x10, 12000000, 125, 2},
+	{ 2822400, 0, 1, 0x00, 0x40, 0x000000, 0x03, 0x10, 11289600, 128, 1},
+	{ 3000000, 0, 1, 0x00, 0x40, 0x000000, 0x03, 0x10, 12000000, 128, 1},
+	{ 3072000, 0, 1, 0x00, 0x3E, 0x800000, 0x03, 0x10, 12000000, 125, 1},
+	{ 4000000, 0, 1, 0x00, 0x30, 0x800000, 0x03, 0x10, 12000000,  96, 1},
+	{ 4096000, 0, 1, 0x00, 0x2E, 0xE00000, 0x03, 0x10, 12000000,  94, 1},
+	{ 5644800, 0, 1, 0x01, 0x40, 0x000000, 0x03, 0x10, 11289600, 128, 1},
+	{ 6000000, 0, 1, 0x01, 0x40, 0x000000, 0x03, 0x10, 12000000, 128, 1},
+	{ 6144000, 0, 1, 0x01, 0x3E, 0x800000, 0x03, 0x10, 12000000, 125, 1},
+	{ 11289600, 0, 0, 0, 0, 0, 0, 0, 11289600, 0, 1},
+	{ 12000000, 0, 0, 0, 0, 0, 0, 0, 12000000, 0, 1},
+	{ 12288000, 0, 0, 0, 0, 0, 0, 0, 12288000, 0, 1},
+	{ 22579200, 1, 0, 0, 0, 0, 0, 0, 22579200, 0, 1},
+	{ 24000000, 1, 0, 0, 0, 0, 0, 0, 24000000, 0, 1},
+	{ 24576000, 1, 0, 0, 0, 0, 0, 0, 24576000, 0, 1}
 };
 
 static int cs42l42_pll_config(struct snd_soc_component *component)
@@ -746,8 +747,12 @@ static int cs42l42_pll_config(struct snd_soc_component *component)
 				snd_soc_component_update_bits(component,
 					CS42L42_PLL_CTL3,
 					CS42L42_PLL_DIVOUT_MASK,
-					pll_ratio_table[i].pll_divout
+					(pll_ratio_table[i].pll_divout * pll_ratio_table[i].n)
 					<< CS42L42_PLL_DIVOUT_SHIFT);
+				if (pll_ratio_table[i].n != 1)
+					cs42l42->pll_divout = pll_ratio_table[i].pll_divout;
+				else
+					cs42l42->pll_divout = 0;
 				snd_soc_component_update_bits(component,
 					CS42L42_PLL_CAL_RATIO,
 					CS42L42_PLL_CAL_RATIO_MASK,
@@ -902,6 +907,16 @@ static int cs42l42_mute_stream(struct snd_soc_dai *dai, int mute, int stream)
 			if ((cs42l42->bclk < 11289600) && (cs42l42->sclk < 11289600)) {
 				snd_soc_component_update_bits(component, CS42L42_PLL_CTL1,
 							      CS42L42_PLL_START_MASK, 1);
+
+				if (cs42l42->pll_divout) {
+					usleep_range(CS42L42_PLL_DIVOUT_TIME_US,
+						     CS42L42_PLL_DIVOUT_TIME_US * 2);
+					snd_soc_component_update_bits(component, CS42L42_PLL_CTL3,
+								      CS42L42_PLL_DIVOUT_MASK,
+								      cs42l42->pll_divout <<
+								      CS42L42_PLL_DIVOUT_SHIFT);
+				}
+
 				ret = regmap_read_poll_timeout(cs42l42->regmap,
 							       CS42L42_PLL_LOCK_STATUS,
 							       regval,

sound/soc/codecs/cs42l42.h

@@ -755,6 +755,7 @@
 
 #define CS42L42_NUM_SUPPLIES	5
 #define CS42L42_BOOT_TIME_US	3000
+#define CS42L42_PLL_DIVOUT_TIME_US	800
 #define CS42L42_CLOCK_SWITCH_DELAY_US 150
 #define CS42L42_PLL_LOCK_POLL_US	250
 #define CS42L42_PLL_LOCK_TIMEOUT_US	1250
@@ -777,6 +778,7 @@ struct  cs42l42_private {
 	int bclk;
 	u32 sclk;
 	u32 srate;
+	u8 pll_divout;
 	u8 plug_state;
 	u8 hs_type;
 	u8 ts_inv;