[PATCH v4 3/6] iio: imu: st_lsm6dsx: add wakeup-source option

[Sean Nyekjaer <sean@geanix.com>]

This add ways for the SoC to wake from accelerometer wake events.

In the suspend function we skip disabling the sensor if wakeup-source
and events are activated.

Signed-off-by: Sean Nyekjaer <sean@geanix.com>
---
 drivers/iio/imu/st_lsm6dsx/st_lsm6dsx_core.c | 14 ++++++++++++++
 1 file changed, 14 insertions(+)

diff --git a/drivers/iio/imu/st_lsm6dsx/st_lsm6dsx_core.c b/drivers/iio/imu/st_lsm6dsx/st_lsm6dsx_core.c
index 7761ee5b1ec7..2dda0f90a816 100644
--- a/drivers/iio/imu/st_lsm6dsx/st_lsm6dsx_core.c
+++ b/drivers/iio/imu/st_lsm6dsx/st_lsm6dsx_core.c
@@ -1755,6 +1755,9 @@ int st_lsm6dsx_probe(struct device *dev, int irq, int hw_id,
 			return err;
 	}
 
+	if (dev->of_node && of_property_read_bool(dev->of_node, "wakeup-source"))
+		device_init_wakeup(dev, true);
+
 	return 0;
 }
 EXPORT_SYMBOL(st_lsm6dsx_probe);
@@ -1773,6 +1776,12 @@ static int __maybe_unused st_lsm6dsx_suspend(struct device *dev)
 		if (!(hw->enable_mask & BIT(sensor->id)))
 			continue;
 
+		if (device_may_wakeup(dev) && i == ST_LSM6DSX_ID_ACC) {
+			/* Enable wake from IRQ */
+			enable_irq_wake(hw->irq);
+			continue;
+		}
+
 		if (sensor->id == ST_LSM6DSX_ID_EXT0 ||
 		    sensor->id == ST_LSM6DSX_ID_EXT1 ||
 		    sensor->id == ST_LSM6DSX_ID_EXT2)
@@ -1805,6 +1814,11 @@ static int __maybe_unused st_lsm6dsx_resume(struct device *dev)
 		if (!(hw->suspend_mask & BIT(sensor->id)))
 			continue;
 
+		if (device_may_wakeup(dev) && i == ST_LSM6DSX_ID_ACC) {
+			disable_irq_wake(hw->irq);
+			continue;
+		}
+
 		if (sensor->id == ST_LSM6DSX_ID_EXT0 ||
 		    sensor->id == ST_LSM6DSX_ID_EXT1 ||
 		    sensor->id == ST_LSM6DSX_ID_EXT2)
-- 
2.23.0