linux-kernel - [PATCH v1 2/3] ASoC: cs42l42: Don't rely on GPIOD_OUT

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Message-ID: <20230913150012.604775-3-sbinding@opensource.cirrus.com>
Date:   Wed, 13 Sep 2023 16:00:11 +0100
From:   Stefan Binding <sbinding@...nsource.cirrus.com>
To:     Mark Brown <broonie@...nel.org>,
        Uday M Bhat <uday.m.bhat@...el.com>,
        Pierre-Louis Bossart <pierre-louis.bossart@...ux.intel.com>
CC:     <alsa-devel@...a-project.org>, <linux-kernel@...r.kernel.org>,
        <patches@...nsource.cirrus.com>,
        Richard Fitzgerald <rf@...nsource.cirrus.com>,
        Stefan Binding <sbinding@...nsource.cirrus.com>
Subject: [PATCH v1 2/3] ASoC: cs42l42: Don't rely on GPIOD_OUT_LOW to set RESET initially low

From: Richard Fitzgerald <rf@...nsource.cirrus.com>

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>
Signed-off-by: Stefan Binding <sbinding@...nsource.cirrus.com>
---
 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