linux-kernel - [PATCH v2] ASoC: tas5805m: fix pdn polarity

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Date:   Wed,  9 Mar 2022 13:56:49 +0000
From:   John Keeping <john@...anate.com>
To:     alsa-devel@...a-project.org
Cc:     John Keeping <john@...anate.com>,
        Liam Girdwood <lgirdwood@...il.com>,
        Mark Brown <broonie@...nel.org>,
        Jaroslav Kysela <perex@...ex.cz>,
        Takashi Iwai <tiwai@...e.com>,
        Daniel Beer <daniel.beer@...rinstitute.com>,
        linux-kernel@...r.kernel.org
Subject: [PATCH v2] ASoC: tas5805m: fix pdn polarity

The binding defines the GPIO as "pdn-gpios" so when the GPIO is active
the expectation is that the power down signal is asserted and this is
how all other drivers using this GPIO name interpret the value.

But the tas5805m driver inverts the sense from the normal expectation so
when the powerdown GPIO is logically asserted the chip is running.

This is a new driver that is not yet in a released kernel and has no
in-tree users of the binding so fix the sense of the GPIO so that
logically asserted means that the device is powered down.

Rename the variable to match so that the compiler will catch any places
that should have been updated but have been missed.

Fixes: ec45268467f4 ("ASoC: add support for TAS5805M digital amplifier")
Signed-off-by: John Keeping <john@...anate.com>
---
v2:
- Rewrite commit message to make it more obvious that this is a change
  to the interpretation of the GPIO in the binding

 sound/soc/codecs/tas5805m.c | 16 ++++++++--------
 1 file changed, 8 insertions(+), 8 deletions(-)

diff --git a/sound/soc/codecs/tas5805m.c b/sound/soc/codecs/tas5805m.c
index fa0e81ec875a..12146a860ef8 100644
--- a/sound/soc/codecs/tas5805m.c
+++ b/sound/soc/codecs/tas5805m.c
@@ -155,7 +155,7 @@ static const uint32_t tas5805m_volume[] = {
 
 struct tas5805m_priv {
 	struct regulator		*pvdd;
-	struct gpio_desc		*gpio_pdn_n;
+	struct gpio_desc		*gpio_pdn;
 
 	uint8_t				*dsp_cfg_data;
 	int				dsp_cfg_len;
@@ -444,11 +444,11 @@ static int tas5805m_i2c_probe(struct i2c_client *i2c)
 
 	dev_set_drvdata(dev, tas5805m);
 	tas5805m->regmap = regmap;
-	tas5805m->gpio_pdn_n = devm_gpiod_get(dev, "pdn", GPIOD_OUT_LOW);
-	if (IS_ERR(tas5805m->gpio_pdn_n)) {
+	tas5805m->gpio_pdn = devm_gpiod_get(dev, "pdn", GPIOD_OUT_HIGH);
+	if (IS_ERR(tas5805m->gpio_pdn)) {
 		dev_err(dev, "error requesting PDN gpio: %ld\n",
-			PTR_ERR(tas5805m->gpio_pdn_n));
-		return PTR_ERR(tas5805m->gpio_pdn_n);
+			PTR_ERR(tas5805m->gpio_pdn));
+		return PTR_ERR(tas5805m->gpio_pdn);
 	}
 
 	/* This configuration must be generated by PPC3. The file loaded
@@ -505,7 +505,7 @@ static int tas5805m_i2c_probe(struct i2c_client *i2c)
 	}
 
 	usleep_range(100000, 150000);
-	gpiod_set_value(tas5805m->gpio_pdn_n, 1);
+	gpiod_set_value(tas5805m->gpio_pdn, 0);
 	usleep_range(10000, 15000);
 
 	/* Don't register through devm. We need to be able to unregister
@@ -515,7 +515,7 @@ static int tas5805m_i2c_probe(struct i2c_client *i2c)
 					 &tas5805m_dai, 1);
 	if (ret < 0) {
 		dev_err(dev, "unable to register codec: %d\n", ret);
-		gpiod_set_value(tas5805m->gpio_pdn_n, 0);
+		gpiod_set_value(tas5805m->gpio_pdn, 1);
 		regulator_disable(tas5805m->pvdd);
 		return ret;
 	}
@@ -529,7 +529,7 @@ static int tas5805m_i2c_remove(struct i2c_client *i2c)
 	struct tas5805m_priv *tas5805m = dev_get_drvdata(dev);
 
 	snd_soc_unregister_component(dev);
-	gpiod_set_value(tas5805m->gpio_pdn_n, 0);
+	gpiod_set_value(tas5805m->gpio_pdn, 1);
 	usleep_range(10000, 15000);
 	regulator_disable(tas5805m->pvdd);
 	return 0;
-- 
2.35.1