[PATCH v1 2/3] ASoC: cs42l42: Don't rely on GPIOD_OUT_LOW to set RESET initially low

From: Stefan Binding
Date: Wed Sep 13 2023 - 11:00:35 EST


From: Richard Fitzgerald <rf@xxxxxxxxxxxxxxxxxxxxx>

The ACPI setting for a GPIO default state has higher priority than the
flag passed to devm_gpiod_get_optional() so ACPI can override the
GPIOD_OUT_LOW. Explicitly set the GPIO low when hard resetting.

Although GPIOD_OUT_LOW can't be relied on this doesn't seem like a
reason to stop passing it to devm_gpiod_get_optional(). So we still pass
it to state our intent, but can deal with it having no effect.

Signed-off-by: Richard Fitzgerald <rf@xxxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Stefan Binding <sbinding@xxxxxxxxxxxxxxxxxxxxx>
---
sound/soc/codecs/cs42l42.c | 6 ++++++
1 file changed, 6 insertions(+)

diff --git a/sound/soc/codecs/cs42l42.c b/sound/soc/codecs/cs42l42.c
index 56d2857a4f01..dc93861ddfb0 100644
--- a/sound/soc/codecs/cs42l42.c
+++ b/sound/soc/codecs/cs42l42.c
@@ -2321,6 +2321,12 @@ int cs42l42_common_probe(struct cs42l42_private *cs42l42,
if (cs42l42->reset_gpio) {
dev_dbg(cs42l42->dev, "Found reset GPIO\n");

+ /*
+ * 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);

--
2.34.1