[PATCH v2 0/2] add the capability to disable st_lsm6dsx sensor-hub

[PATCH v2 0/2] add the capability to disable st_lsm6dsx sensor-hub

[Lorenzo Bianconi]

Introduce the capability to disable sensorhub through a device-tree property
since 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.

Changes since v1:
- rename disable-shub property in disable-sensor-hub
- improve commit log

Lorenzo Bianconi (2):
  iio: imu: st_lsm6dsx: add dts property to disable sensor-hub
  Documentation: dt: iio: st_lsm6dsx: add disable-sensor-hub property

 Documentation/devicetree/bindings/iio/imu/st,lsm6dsx.yaml | 7 +++++++
 drivers/iio/imu/st_lsm6dsx/st_lsm6dsx_core.c              | 4 +++-
 2 files changed, 10 insertions(+), 1 deletion(-)

-- 
2.31.1

[PATCH v2 1/2] iio: imu: st_lsm6dsx: add dts property to disable sensor-hub

[Lorenzo Bianconi]

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..727b4b6ac696 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-sensor-hub"))) {
 		err = st_lsm6dsx_shub_probe(hw, name);
 		if (err < 0)
 			return err;
-- 
2.31.1

[PATCH v2 2/2] Documentation: dt: iio: st_lsm6dsx: add disable-sensor-hub property

[Lorenzo Bianconi]

Enable/disable internal i2c controller slave autoprobing at bootstrap.
Disable sensor-hub is useful if i2c controller clock/data lines are
connected through a pull-up with other chip lines (e.g. SDO/SA0).

Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org>
---
 Documentation/devicetree/bindings/iio/imu/st,lsm6dsx.yaml | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/Documentation/devicetree/bindings/iio/imu/st,lsm6dsx.yaml b/Documentation/devicetree/bindings/iio/imu/st,lsm6dsx.yaml
index d9b3213318fb..0750f700a143 100644
--- a/Documentation/devicetree/bindings/iio/imu/st,lsm6dsx.yaml
+++ b/Documentation/devicetree/bindings/iio/imu/st,lsm6dsx.yaml
@@ -61,6 +61,13 @@ properties:
     type: boolean
     description: enable/disable internal i2c controller pullup resistors.
 
+  st,disable-sensor-hub:
+    type: boolean
+    description:
+      Enable/disable internal i2c controller slave autoprobing at bootstrap.
+      Disable sensor-hub is useful if i2c controller clock/data lines are
+      connected through a pull-up with other chip lines (e.g. SDO/SA0).
+
   drive-open-drain:
     type: boolean
     description:
-- 
2.31.1

Re: [PATCH v2 2/2] Documentation: dt: iio: st_lsm6dsx: add disable-sensor-hub property

[Rob Herring]

On Sat, 13 Nov 2021 16:23:15 +0100, Lorenzo Bianconi wrote:
> Enable/disable internal i2c controller slave autoprobing at bootstrap.
> Disable sensor-hub is useful if i2c controller clock/data lines are
> connected through a pull-up with other chip lines (e.g. SDO/SA0).
> 
> Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org>
> ---
>  Documentation/devicetree/bindings/iio/imu/st,lsm6dsx.yaml | 7 +++++++
>  1 file changed, 7 insertions(+)
> 

Reviewed-by: Rob Herring <robh@kernel.org>

Re: [PATCH v2 2/2] Documentation: dt: iio: st_lsm6dsx: add disable-sensor-hub property

[Jonathan Cameron]

On Mon, 29 Nov 2021 15:26:17 -0600
Rob Herring <robh@kernel.org> wrote:

> On Sat, 13 Nov 2021 16:23:15 +0100, Lorenzo Bianconi wrote:
> > Enable/disable internal i2c controller slave autoprobing at bootstrap.
> > Disable sensor-hub is useful if i2c controller clock/data lines are
> > connected through a pull-up with other chip lines (e.g. SDO/SA0).
> > 
> > Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org>
> > ---
> >  Documentation/devicetree/bindings/iio/imu/st,lsm6dsx.yaml | 7 +++++++
> >  1 file changed, 7 insertions(+)
> >   
> 
> Reviewed-by: Rob Herring <robh@kernel.org>

Series applied to the togreg branch of iio.git

Thanks,

Jonathan