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authorMark Brown <broonie@kernel.org>2023-09-14 00:46:18 +0300
committerMark Brown <broonie@kernel.org>2023-09-14 00:46:18 +0300
commitef3e1b8a31f3579b7dae2077f501974aca3beb74 (patch)
treed248a8ac00075ef927ca9c6251b22140127de50b /sound/soc
parent781118bc2fc1026c8285f83ea7ecab07071a09c4 (diff)
parent2d066c6a78654c179f95c9beda1985d4c6befa4e (diff)
downloadlinux-ef3e1b8a31f3579b7dae2077f501974aca3beb74.tar.xz
ASoC: cs42l42: Fix handling of hard reset
Merge series from Stefan Binding <sbinding@opensource.cirrus.com>: These patches fix 3 problems with hard reset: 1. Ensure a minimum reset pulse width 2. Deal with ACPI overriding the requested default GPIO state 3. Avoid a race condition when hard-resetting a SoundWire peripheral that is already enumerated
Diffstat (limited to 'sound/soc')
-rw-r--r--sound/soc/codecs/cs42l42-sdw.c20
-rw-r--r--sound/soc/codecs/cs42l42.c21
-rw-r--r--sound/soc/codecs/cs42l42.h1
3 files changed, 41 insertions, 1 deletions
diff --git a/sound/soc/codecs/cs42l42-sdw.c b/sound/soc/codecs/cs42l42-sdw.c
index eeab07c850f9..974bae4abfad 100644
--- a/sound/soc/codecs/cs42l42-sdw.c
+++ b/sound/soc/codecs/cs42l42-sdw.c
@@ -344,6 +344,16 @@ static int cs42l42_sdw_update_status(struct sdw_slave *peripheral,
switch (status) {
case SDW_SLAVE_ATTACHED:
dev_dbg(cs42l42->dev, "ATTACHED\n");
+
+ /*
+ * The SoundWire core can report stale ATTACH notifications
+ * if we hard-reset CS42L42 in probe() but it had already been
+ * enumerated. Reject the ATTACH if we haven't yet seen an
+ * UNATTACH report for the device being in reset.
+ */
+ if (cs42l42->sdw_waiting_first_unattach)
+ break;
+
/*
* Initialise codec, this only needs to be done once.
* When resuming from suspend, resume callback will handle re-init of codec,
@@ -354,6 +364,16 @@ static int cs42l42_sdw_update_status(struct sdw_slave *peripheral,
break;
case SDW_SLAVE_UNATTACHED:
dev_dbg(cs42l42->dev, "UNATTACHED\n");
+
+ if (cs42l42->sdw_waiting_first_unattach) {
+ /*
+ * SoundWire core has seen that CS42L42 is not on
+ * the bus so release RESET and wait for ATTACH.
+ */
+ cs42l42->sdw_waiting_first_unattach = false;
+ gpiod_set_value_cansleep(cs42l42->reset_gpio, 1);
+ }
+
break;
default:
break;
diff --git a/sound/soc/codecs/cs42l42.c b/sound/soc/codecs/cs42l42.c
index a0de0329406a..2961340f15e2 100644
--- a/sound/soc/codecs/cs42l42.c
+++ b/sound/soc/codecs/cs42l42.c
@@ -2320,7 +2320,26 @@ int cs42l42_common_probe(struct cs42l42_private *cs42l42,
if (cs42l42->reset_gpio) {
dev_dbg(cs42l42->dev, "Found reset GPIO\n");
- gpiod_set_value_cansleep(cs42l42->reset_gpio, 1);
+
+ /*
+ * ACPI can override the default GPIO state we requested
+ * so ensure that we start with RESET low.
+ */
+ gpiod_set_value_cansleep(cs42l42->reset_gpio, 0);
+
+ /* Ensure minimum reset pulse width */
+ usleep_range(10, 500);
+
+ /*
+ * On SoundWire keep the chip in reset until we get an UNATTACH
+ * notification from the SoundWire core. This acts as a
+ * synchronization point to reject stale ATTACH notifications
+ * if the chip was already enumerated before we reset it.
+ */
+ if (cs42l42->sdw_peripheral)
+ cs42l42->sdw_waiting_first_unattach = true;
+ else
+ gpiod_set_value_cansleep(cs42l42->reset_gpio, 1);
}
usleep_range(CS42L42_BOOT_TIME_US, CS42L42_BOOT_TIME_US * 2);
diff --git a/sound/soc/codecs/cs42l42.h b/sound/soc/codecs/cs42l42.h
index 4bd7b85a5747..7785125b73ab 100644
--- a/sound/soc/codecs/cs42l42.h
+++ b/sound/soc/codecs/cs42l42.h
@@ -53,6 +53,7 @@ struct cs42l42_private {
u8 stream_use;
bool hp_adc_up_pending;
bool suspended;
+ bool sdw_waiting_first_unattach;
bool init_done;
};