linux-kernel - [PATCH v7 1/7] iio: accel: adxl345: add function to switch measuring mode

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Message-Id: <20241213211909.40896-2-l.rubusch@gmail.com>
Date: Fri, 13 Dec 2024 21:19:03 +0000
From: Lothar Rubusch <l.rubusch@...il.com>
To: lars@...afoo.de,
	Michael.Hennerich@...log.com,
	jic23@...nel.org,
	robh@...nel.org,
	krzk+dt@...nel.org,
	conor+dt@...nel.org
Cc: devicetree@...r.kernel.org,
	linux-iio@...r.kernel.org,
	linux-kernel@...r.kernel.org,
	eraretuya@...il.com,
	l.rubusch@...il.com
Subject: [PATCH v7 1/7] iio: accel: adxl345: add function to switch measuring mode

Replace the powerup / powerdown functions by a generic function to put
the sensor in STANDBY, or MEASURE mode. When configuring the FIFO for
several features of the accelerometer, it is recommended to put
measuring in STANDBY mode.

Signed-off-by: Lothar Rubusch <l.rubusch@...il.com>
---
 drivers/iio/accel/adxl345_core.c | 42 +++++++++++++++++++++++---------
 1 file changed, 30 insertions(+), 12 deletions(-)

diff --git a/drivers/iio/accel/adxl345_core.c b/drivers/iio/accel/adxl345_core.c
index 88df9547b..b48bc838c 100644
--- a/drivers/iio/accel/adxl345_core.c
+++ b/drivers/iio/accel/adxl345_core.c
@@ -138,6 +138,34 @@ static int adxl345_write_raw_get_fmt(struct iio_dev *indio_dev,
 	}
 }
 
+/**
+ * adxl345_set_measure_en() - Enable and disable measuring.
+ *
+ * @st: The device data.
+ * @en: Enable measurements, else standby mode.
+ *
+ * For lowest power operation, standby mode can be used. In standby mode,
+ * current consumption is supposed to be reduced to 0.1uA (typical). In this
+ * mode no measurements are made. Placing the device into standby mode
+ * preserves the contents of FIFO.
+ *
+ * Return: Returns 0 if successful, or a negative error value.
+ */
+static int adxl345_set_measure_en(struct adxl345_state *st, bool en)
+{
+	unsigned int val = 0;
+
+	val = (en) ? ADXL345_POWER_CTL_MEASURE : ADXL345_POWER_CTL_STANDBY;
+	return regmap_write(st->regmap, ADXL345_REG_POWER_CTL, val);
+}
+
+static void adxl345_powerdown(void *ptr)
+{
+	struct adxl345_state *st = ptr;
+
+	adxl345_set_measure_en(st, false);
+}
+
 static IIO_CONST_ATTR_SAMP_FREQ_AVAIL(
 "0.09765625 0.1953125 0.390625 0.78125 1.5625 3.125 6.25 12.5 25 50 100 200 400 800 1600 3200"
 );
@@ -158,16 +186,6 @@ static const struct iio_info adxl345_info = {
 	.write_raw_get_fmt	= adxl345_write_raw_get_fmt,
 };
 
-static int adxl345_powerup(void *regmap)
-{
-	return regmap_write(regmap, ADXL345_REG_POWER_CTL, ADXL345_POWER_CTL_MEASURE);
-}
-
-static void adxl345_powerdown(void *regmap)
-{
-	regmap_write(regmap, ADXL345_REG_POWER_CTL, ADXL345_POWER_CTL_STANDBY);
-}
-
 /**
  * adxl345_core_probe() - Probe and setup for the accelerometer.
  * @dev:	Driver model representation of the device
@@ -237,11 +255,11 @@ int adxl345_core_probe(struct device *dev, struct regmap *regmap,
 				     regval, ADXL345_DEVID);
 
 	/* Enable measurement mode */
-	ret = adxl345_powerup(st->regmap);
+	ret = adxl345_set_measure_en(st, true);
 	if (ret < 0)
 		return dev_err_probe(dev, ret, "Failed to enable measurement mode\n");
 
-	ret = devm_add_action_or_reset(dev, adxl345_powerdown, st->regmap);
+	ret = devm_add_action_or_reset(dev, adxl345_powerdown, st);
 	if (ret < 0)
 		return ret;
 
-- 
2.39.5