linux-kernel - [PATCH 2/6] ASoC: tas2770: Add shutdown capability via a GPIO

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Date:   Wed, 23 Sep 2020 08:25:56 -0500
From:   Dan Murphy <dmurphy@...com>
To:     <lgirdwood@...il.com>, <broonie@...nel.org>, <tiwai@...e.com>,
        <robh+dt@...nel.org>
CC:     <devicetree@...r.kernel.org>, <alsa-devel@...a-project.org>,
        <linux-kernel@...r.kernel.org>, Dan Murphy <dmurphy@...com>
Subject: [PATCH 2/6] ASoC: tas2770: Add shutdown capability via a GPIO

Add the hardware shutdown mechanism to shutdown and wake up the device
via a GPIO.

Signed-off-by: Dan Murphy <dmurphy@...com>
---
 sound/soc/codecs/tas2770.c | 53 ++++++++++++++++++++++++++++----------
 sound/soc/codecs/tas2770.h |  1 +
 2 files changed, 40 insertions(+), 14 deletions(-)

diff --git a/sound/soc/codecs/tas2770.c b/sound/soc/codecs/tas2770.c
index 386aaa11fa08..9f7363927c50 100644
--- a/sound/soc/codecs/tas2770.c
+++ b/sound/soc/codecs/tas2770.c
@@ -79,28 +79,42 @@ static int tas2770_set_bias_level(struct snd_soc_component *component,
 #ifdef CONFIG_PM
 static int tas2770_codec_suspend(struct snd_soc_component *component)
 {
-	int ret;
+	struct tas2770_priv *tas2770 = snd_soc_component_get_drvdata(component);
+	int ret = 0;
 
-	ret = snd_soc_component_update_bits(component, TAS2770_PWR_CTRL,
-					    TAS2770_PWR_CTRL_MASK,
-					    TAS2770_PWR_CTRL_SHUTDOWN);
-	if (ret < 0)
-		return ret;
+	if (tas2770->sdz_gpio) {
+		gpiod_set_value_cansleep(tas2770->sdz_gpio, 0);
+	} else {
+		ret = snd_soc_component_update_bits(component, TAS2770_PWR_CTRL,
+						    TAS2770_PWR_CTRL_MASK,
+						    TAS2770_PWR_CTRL_SHUTDOWN);
+		if (ret < 0)
+			return ret;
 
-	return 0;
+		ret = 0;
+	}
+
+	return ret;
 }
 
 static int tas2770_codec_resume(struct snd_soc_component *component)
 {
-	int ret;
+	struct tas2770_priv *tas2770 = snd_soc_component_get_drvdata(component);
+	int ret = 0;
 
-	ret = snd_soc_component_update_bits(component, TAS2770_PWR_CTRL,
-					    TAS2770_PWR_CTRL_MASK,
-					    TAS2770_PWR_CTRL_ACTIVE);
-	if (ret < 0)
-		return ret;
+	if (tas2770->sdz_gpio) {
+		gpiod_set_value_cansleep(tas2770->sdz_gpio, 1);
+	} else {
+		ret = snd_soc_component_update_bits(component, TAS2770_PWR_CTRL,
+						    TAS2770_PWR_CTRL_MASK,
+						    TAS2770_PWR_CTRL_ACTIVE);
+		if (ret < 0)
+			return ret;
 
-	return 0;
+		ret = 0;
+	}
+
+	return ret;
 }
 #else
 #define tas2770_codec_suspend NULL
@@ -498,6 +512,9 @@ static int tas2770_codec_probe(struct snd_soc_component *component)
 
 	tas2770->component = component;
 
+	if (tas2770->sdz_gpio)
+		gpiod_set_value_cansleep(tas2770->sdz_gpio, 1);
+
 	tas2770_reset(tas2770);
 
 	return 0;
@@ -650,6 +667,14 @@ static int tas2770_parse_dt(struct device *dev, struct tas2770_priv *tas2770)
 		tas2770->v_sense_slot = 2;
 	}
 
+	tas2770->sdz_gpio = devm_gpiod_get_optional(dev, "shutdown", GPIOD_OUT_HIGH);
+	if (IS_ERR(tas2770->sdz_gpio)) {
+		if (PTR_ERR(tas2770->sdz_gpio) == -EPROBE_DEFER)
+			return -EPROBE_DEFER;
+
+		tas2770->sdz_gpio = NULL;
+	}
+
 	return 0;
 }
 
diff --git a/sound/soc/codecs/tas2770.h b/sound/soc/codecs/tas2770.h
index 07e3556fc702..b3fc4a487033 100644
--- a/sound/soc/codecs/tas2770.h
+++ b/sound/soc/codecs/tas2770.h
@@ -134,6 +134,7 @@ struct tas2770_priv {
 	int power_state;
 	int asi_format;
 	struct gpio_desc *reset_gpio;
+	struct gpio_desc *sdz_gpio;
 	int sampling_rate;
 	int channel_size;
 	int slot_width;
-- 
2.28.0