[PATCH v1 3/8] ALSA: hda: cs35l41: Assert Reset prior to de-asserting in probe and system resume

From: Stefan Binding
Date: Thu Oct 26 2023 - 11:06:56 EST


To ensure we are in a known state, exiting from reset at the point of
probe or in system resume, assert reset before we de-assert it.

Since the BIOS may enter into a pre-boot environment to control the
amps (for example for boot beep), we need to ensure we start from a
known, reset state prior to probe or system resume.

Signed-off-by: Stefan Binding <sbinding@xxxxxxxxxxxxxxxxxxxxx>
---
sound/pci/hda/cs35l41_hda.c | 2 ++
1 file changed, 2 insertions(+)

diff --git a/sound/pci/hda/cs35l41_hda.c b/sound/pci/hda/cs35l41_hda.c
index 919e38213975..1ac721085fb5 100644
--- a/sound/pci/hda/cs35l41_hda.c
+++ b/sound/pci/hda/cs35l41_hda.c
@@ -840,6 +840,7 @@ static int cs35l41_system_resume(struct device *dev)
}

if (cs35l41->reset_gpio) {
+ gpiod_set_value_cansleep(cs35l41->reset_gpio, 0);
usleep_range(2000, 2100);
gpiod_set_value_cansleep(cs35l41->reset_gpio, 1);
}
@@ -1693,6 +1694,7 @@ int cs35l41_hda_probe(struct device *dev, const char *device_name, int id, int i
}
}
if (cs35l41->reset_gpio) {
+ gpiod_set_value_cansleep(cs35l41->reset_gpio, 0);
usleep_range(2000, 2100);
gpiod_set_value_cansleep(cs35l41->reset_gpio, 1);
}
--
2.34.1