[PATCH 1/2] iio: imu: st_lsm6dsx: add dts property to disable sensor-hub

[Lorenzo Bianconi <lorenzo@kernel.org>]

Introduce the capability to disable sensorhub through a device-tree
property since there are some configurations where users want to
explicitly disable sensor-hub auto-probing at bootstrap.
A typical configuration is when the sensorhub clock/data lines are connected
to a pull-up resistor since no slave sensors are connected to the i2c master.
If SDO/SA0 line is connected to the same pull-up resistor, when the driver
tries to probe slave devices connected on sensor-hub, it will force SDO/SA0
line to low, modifying the device i2c address.

Tested-by: Mario Tesi <mario.tesi@st.com>
Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org>
---
 drivers/iio/imu/st_lsm6dsx/st_lsm6dsx_core.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/drivers/iio/imu/st_lsm6dsx/st_lsm6dsx_core.c b/drivers/iio/imu/st_lsm6dsx/st_lsm6dsx_core.c
index f2cbbc756459..82ac6c59ca03 100644
--- a/drivers/iio/imu/st_lsm6dsx/st_lsm6dsx_core.c
+++ b/drivers/iio/imu/st_lsm6dsx/st_lsm6dsx_core.c
@@ -2244,7 +2244,9 @@ int st_lsm6dsx_probe(struct device *dev, int irq, int hw_id,
 		return err;
 
 	hub_settings = &hw->settings->shub_settings;
-	if (hub_settings->master_en.addr) {
+	if (hub_settings->master_en.addr &&
+	    (!dev_fwnode(dev) ||
+	     !device_property_read_bool(dev, "st,disable-shub"))) {
 		err = st_lsm6dsx_shub_probe(hw, name);
 		if (err < 0)
 			return err;
-- 
2.31.1