[PATCH 1/4] ASoC: cs42l42: Fix 1536000 Bit Clock instability

From: Lucas Tanure
Date: Tue May 25 2021 - 05:09:18 EST


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@xxxxxxxxxxxxxxxxxxxxx>
---
sound/soc/codecs/cs42l42.c | 47 +++++++++++++++++++++++++-------------
sound/soc/codecs/cs42l42.h | 2 ++
2 files changed, 33 insertions(+), 16 deletions(-)

diff --git a/sound/soc/codecs/cs42l42.c b/sound/soc/codecs/cs42l42.c
index b084acd1e86b..94788a55fa3b 100644
--- a/sound/soc/codecs/cs42l42.c
+++ b/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,
diff --git a/sound/soc/codecs/cs42l42.h b/sound/soc/codecs/cs42l42.h
index 24f7be228d5f..7bf05ff05f74 100644
--- a/sound/soc/codecs/cs42l42.h
+++ b/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;
--
2.31.1