On Wed, 10 Nov 2021 15:42:32 +0100
Lorenzo Bianconi <lorenzo@xxxxxxxxxx> wrote:
> 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.
That's some 'interesting' wiring...
My only suggestion here is perhaps expand on shub as disable-sensor-hub
would be easier for people not familiar with the abbreviation?
Jonathan
>
> Tested-by: Mario Tesi <mario.tesi@xxxxxx>
> Signed-off-by: Lorenzo Bianconi <lorenzo@xxxxxxxxxx>
> ---
> 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;
