From: Simon Trimmer simont@opensource.cirrus.com
As the dummy wake is a toggling signal (either I2C or SPI activity) it is not guaranteed to meet the minimum asserted hold time for a wake signal. In this case the wake must guarantee rising edges separated by at least the minimum hold time.
Signed-off-by: Simon Trimmer simont@opensource.cirrus.com Signed-off-by: Richard Fitzgerald rf@opensource.cirrus.com --- include/sound/cs35l56.h | 1 + sound/soc/codecs/cs35l56-shared.c | 51 +++++++++++++++++++++---------- 2 files changed, 36 insertions(+), 16 deletions(-)
diff --git a/include/sound/cs35l56.h b/include/sound/cs35l56.h index 762b96b29211..8c18e8b6d27d 100644 --- a/include/sound/cs35l56.h +++ b/include/sound/cs35l56.h @@ -243,6 +243,7 @@ #define CS35L56_HALO_STATE_POLL_US 1000 #define CS35L56_HALO_STATE_TIMEOUT_US 50000 #define CS35L56_RESET_PULSE_MIN_US 1100 +#define CS35L56_WAKE_HOLD_TIME_US 1000
#define CS35L56_SDW1_PLAYBACK_PORT 1 #define CS35L56_SDW1_CAPTURE_PORT 3 diff --git a/sound/soc/codecs/cs35l56-shared.c b/sound/soc/codecs/cs35l56-shared.c index 68dc93b82789..953ba066bab1 100644 --- a/sound/soc/codecs/cs35l56-shared.c +++ b/sound/soc/codecs/cs35l56-shared.c @@ -446,6 +446,32 @@ static const struct reg_sequence cs35l56_hibernate_wake_seq[] = { REG_SEQ0(CS35L56_DSP_VIRTUAL1_MBOX_1, CS35L56_MBOX_CMD_WAKEUP), };
+static void cs35l56_issue_wake_event(struct cs35l56_base *cs35l56_base) +{ + /* + * Dummy transactions to trigger I2C/SPI auto-wake. Issue two + * transactions to meet the minimum required time from the rising edge + * to the last falling edge of wake. + * + * It uses bypassed write because we must wake the chip before + * disabling regmap cache-only. + * + * This can NAK on I2C which will terminate the write sequence so the + * single-write sequence is issued twice. + */ + regmap_multi_reg_write_bypassed(cs35l56_base->regmap, + cs35l56_hibernate_wake_seq, + ARRAY_SIZE(cs35l56_hibernate_wake_seq)); + + usleep_range(CS35L56_WAKE_HOLD_TIME_US, 2 * CS35L56_WAKE_HOLD_TIME_US); + + regmap_multi_reg_write_bypassed(cs35l56_base->regmap, + cs35l56_hibernate_wake_seq, + ARRAY_SIZE(cs35l56_hibernate_wake_seq)); + + cs35l56_wait_control_port_ready(); +} + int cs35l56_runtime_suspend_common(struct cs35l56_base *cs35l56_base) { unsigned int val; @@ -500,17 +526,9 @@ int cs35l56_runtime_resume_common(struct cs35l56_base *cs35l56_base, bool is_sou if (!cs35l56_base->can_hibernate) goto out_sync;
- if (!is_soundwire) { - /* - * Dummy transaction to trigger I2C/SPI auto-wake. This will NAK on I2C. - * Must be done before releasing cache-only. - */ - regmap_multi_reg_write_bypassed(cs35l56_base->regmap, - cs35l56_hibernate_wake_seq, - ARRAY_SIZE(cs35l56_hibernate_wake_seq)); - - cs35l56_wait_control_port_ready(); - } + /* Must be done before releasing cache-only */ + if (!is_soundwire) + cs35l56_issue_wake_event(cs35l56_base);
out_sync: regcache_cache_only(cs35l56_base->regmap, false); @@ -578,13 +596,14 @@ int cs35l56_hw_init(struct cs35l56_base *cs35l56_base) unsigned int devid, revid, otpid, secured;
/* - * If the system is not using a reset_gpio then issue a - * dummy read to force a wakeup. + * When the system is not using a reset_gpio ensure the device is + * awake, otherwise the device has just been released from reset and + * the driver must wait for the control port to become usable. */ if (!cs35l56_base->reset_gpio) - regmap_read(cs35l56_base->regmap, CS35L56_DSP_VIRTUAL1_MBOX_1, &devid); - - cs35l56_wait_control_port_ready(); + cs35l56_issue_wake_event(cs35l56_base); + else + cs35l56_wait_control_port_ready();
/* * The HALO_STATE register is in different locations on Ax and B0