linux-kernel - [PATCH 2/5] ASoC: cs35l56: Don't rely on GPIOD_OUT

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Date:   Tue, 8 Aug 2023 17:46:59 +0100
From:   Richard Fitzgerald <rf@...nsource.cirrus.com>
To:     <broonie@...nel.org>
CC:     <alsa-devel@...a-project.org>, <linux-kernel@...r.kernel.org>,
        <patches@...nsource.cirrus.com>,
        Richard Fitzgerald <rf@...nsource.cirrus.com>
Subject: [PATCH 2/5] ASoC: cs35l56: Don't rely on GPIOD_OUT_LOW to set RESET initially low

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@...nsource.cirrus.com>
---
 sound/soc/codecs/cs35l56.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/sound/soc/codecs/cs35l56.c b/sound/soc/codecs/cs35l56.c
index be400208205a..9560059c867b 100644
--- a/sound/soc/codecs/cs35l56.c
+++ b/sound/soc/codecs/cs35l56.c
@@ -1069,6 +1069,8 @@ int cs35l56_common_probe(struct cs35l56_private *cs35l56)
 		return dev_err_probe(cs35l56->base.dev, ret, "Failed to enable supplies\n");
 
 	if (cs35l56->base.reset_gpio) {
+		/* ACPI can override GPIOD_OUT_LOW flag so force it to start low */
+		gpiod_set_value_cansleep(cs35l56->base.reset_gpio, 0);
 		cs35l56_wait_min_reset_pulse();
 		gpiod_set_value_cansleep(cs35l56->base.reset_gpio, 1);
 	}
-- 
2.30.2