[PATCH v2 11/12] iio: accel: adxl313: implement power-save on inactivity

[Lothar Rubusch <l.rubusch@gmail.com>]

Link activity and inactivity to indicate the internal power-saving state.
Add auto-sleep to be linked to inactivity.

Signed-off-by: Lothar Rubusch <l.rubusch@gmail.com>
---
 drivers/iio/accel/adxl313.h      |  3 +++
 drivers/iio/accel/adxl313_core.c | 29 ++++++++++++++++++++++++++---
 2 files changed, 29 insertions(+), 3 deletions(-)

diff --git a/drivers/iio/accel/adxl313.h b/drivers/iio/accel/adxl313.h
index 1398ac54d19b..eafdf8f57816 100644
--- a/drivers/iio/accel/adxl313.h
+++ b/drivers/iio/accel/adxl313.h
@@ -41,6 +41,9 @@
 #define ADXL313_RATE_BASE		6
 
 #define ADXL313_POWER_CTL_MSK		BIT(3)
+#define ADXL313_POWER_CTL_INACT_MSK	GENMASK(5, 4)
+#define ADXL313_POWER_CTL_LINK		BIT(5)
+#define ADXL313_POWER_CTL_AUTO_SLEEP	BIT(4)
 #define ADXL313_MEASUREMENT_MODE	BIT(3)
 #define ADXL313_MEASUREMENT_STANDBY	0x00
 
diff --git a/drivers/iio/accel/adxl313_core.c b/drivers/iio/accel/adxl313_core.c
index 7356aacd8874..2b24e6b01f1f 100644
--- a/drivers/iio/accel/adxl313_core.c
+++ b/drivers/iio/accel/adxl313_core.c
@@ -390,6 +390,7 @@ static int adxl313_set_act_inact_en(struct adxl313_data *data,
 	unsigned int axis_ctrl;
 	unsigned int threshold;
 	unsigned int inact_time_s;
+	int act_en, inact_en;
 	bool en;
 	int ret;
 
@@ -418,9 +419,31 @@ static int adxl313_set_act_inact_en(struct adxl313_data *data,
 		en = en && inact_time_s;
 	}
 
-	return regmap_update_bits(data->regmap, ADXL313_REG_INT_ENABLE,
-				  adxl313_act_int_reg[type],
-				  en ? adxl313_act_int_reg[type] : 0);
+	ret = regmap_update_bits(data->regmap, ADXL313_REG_INT_ENABLE,
+				 adxl313_act_int_reg[type],
+				 en ? adxl313_act_int_reg[type] : 0);
+	if (ret)
+		return ret;
+
+	/*
+	 * Advanced power saving: Set sleep and link bit only when ACT and INACT
+	 * are set. Check enable against regmap cached values.
+	 */
+	act_en = adxl313_is_act_inact_en(data, ADXL313_ACTIVITY);
+	if (act_en < 0)
+		return act_en;
+
+	inact_en = adxl313_is_act_inact_en(data, ADXL313_INACTIVITY);
+	if (inact_en < 0)
+		return inact_en;
+
+	en = en && act_en && inact_en;
+
+	return regmap_update_bits(data->regmap,
+				  ADXL313_REG_POWER_CTL,
+				  ADXL313_POWER_CTL_INACT_MSK,
+				  en ?
+				  (ADXL313_POWER_CTL_AUTO_SLEEP | ADXL313_POWER_CTL_LINK) : 0);
 }
 
 static int adxl313_read_raw(struct iio_dev *indio_dev,
-- 
2.39.5