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Subject[PATCH v3 13/15] ASoC: cs42l42: Wait at least 150us after writing SCLK_PRESENT
Date
From: Richard Fitzgerald <rf@opensource.cirrus.com>

There must be a delay of at least 150us after writing SCLK_PRESENT
before issuing another I2C write.

This is done using struct reg_sequence because it can specify a delay
after the write and the whole sequence is written atomically.

Signed-off-by: Richard Fitzgerald <rf@opensource.cirrus.com>
Signed-off-by: Lucas Tanure <tanureal@opensource.cirrus.com>
---
Changes in v3:
- No changes

Changes in v2:
- struct cs42l42_private add by this patch was wrong and moved to the
correct patch
- Lucas signed-off added

sound/soc/codecs/cs42l42.c | 27 ++++++++++++++++++++++-----
sound/soc/codecs/cs42l42.h | 1 +
2 files changed, 23 insertions(+), 5 deletions(-)

diff --git a/sound/soc/codecs/cs42l42.c b/sound/soc/codecs/cs42l42.c
index 68b7ed71ad542..08718fd10fb9b 100644
--- a/sound/soc/codecs/cs42l42.c
+++ b/sound/soc/codecs/cs42l42.c
@@ -549,6 +549,24 @@ static const struct snd_soc_component_driver soc_component_dev_cs42l42 = {
.non_legacy_dai_naming = 1,
};

+/* Switch to SCLK. Atomic delay after the write to allow the switch to complete. */
+static const struct reg_sequence cs42l42_to_sclk_seq[] = {
+ {
+ .reg = CS42L42_OSC_SWITCH,
+ .def = CS42L42_SCLK_PRESENT_MASK,
+ .delay_us = CS42L42_CLOCK_SWITCH_DELAY_US,
+ },
+};
+
+/* Switch to OSC. Atomic delay after the write to allow the switch to complete. */
+static const struct reg_sequence cs42l42_to_osc_seq[] = {
+ {
+ .reg = CS42L42_OSC_SWITCH,
+ .def = 0,
+ .delay_us = CS42L42_CLOCK_SWITCH_DELAY_US,
+ },
+};
+
struct cs42l42_pll_params {
u32 sclk;
u8 mclk_div;
@@ -861,8 +879,8 @@ static int cs42l42_mute_stream(struct snd_soc_dai *dai, int mute, int stream)
* SCLK must remain running until after this clock switch.
* Without a source of clock the I2C bus doesn't work.
*/
- snd_soc_component_update_bits(component, CS42L42_OSC_SWITCH,
- CS42L42_SCLK_PRESENT_MASK, 0);
+ regmap_multi_reg_write(cs42l42->regmap, cs42l42_to_osc_seq,
+ ARRAY_SIZE(cs42l42_to_osc_seq));
snd_soc_component_update_bits(component, CS42L42_PLL_CTL1,
CS42L42_PLL_START_MASK, 0);
}
@@ -873,9 +891,8 @@ static int cs42l42_mute_stream(struct snd_soc_dai *dai, int mute, int stream)
CS42L42_PLL_START_MASK, 1);

/* Mark SCLK as present, turn off internal oscillator */
- snd_soc_component_update_bits(component, CS42L42_OSC_SWITCH,
- CS42L42_SCLK_PRESENT_MASK,
- CS42L42_SCLK_PRESENT_MASK);
+ regmap_multi_reg_write(cs42l42->regmap, cs42l42_to_sclk_seq,
+ ARRAY_SIZE(cs42l42_to_sclk_seq));
}
cs42l42->stream_use |= 1 << stream;

diff --git a/sound/soc/codecs/cs42l42.h b/sound/soc/codecs/cs42l42.h
index 429c6833fc811..214cee762709d 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_CLOCK_SWITCH_DELAY_US 150

static const char *const cs42l42_supply_names[CS42L42_NUM_SUPPLIES] = {
"VA",
--
2.30.1
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