Re: [PATCH v3 2/4] dt-bindings: iio: magnetometer: ak8975: add gpio reset support

Jonathan Albrieux
2020-05-19T14:09:39Z

On Tue, May 19, 2020 at 03:23:54PM +0200, Stephan Gerhold wrote:
> On Tue, May 19, 2020 at 02:43:52PM +0200, Jonathan Albrieux wrote:
> > Add reset-gpio support.
> >
> > Without reset's deassertion during ak8975_power_on(), driver's probe fails
> > on ak8975_who_i_am() while checking for device identity for AK09911 chip.
> >
> > AK09911 has an active low reset gpio to handle register's reset.
> > AK09911 datasheed says that, if not used, reset pin should be connected
>
> datasheed -> datasheet
>

Will fix that soon

> > to VID. This patch emulates this situation.
> >
> > Signed-off-by: Jonathan Albrieux <jonathan.albrieux@gmail.com>
> > ---
> > .../devicetree/bindings/iio/magnetometer/ak8975.yaml | 4 ++++
> > 1 file changed, 4 insertions(+)
> >
> > diff --git a/Documentation/devicetree/bindings/iio/magnetometer/ak8975.yaml b/Documentation/devicetree/bindings/iio/magnetometer/ak8975.yaml
> > index 86e3efa693a8..a82c0ff5d098 100644
> > --- a/Documentation/devicetree/bindings/iio/magnetometer/ak8975.yaml
> > +++ b/Documentation/devicetree/bindings/iio/magnetometer/ak8975.yaml
> > @@ -37,6 +37,9 @@ properties:
> > mount-matrix:
> > description: an optional 3x3 mounting rotation matrix
> >
> > + reset-gpio:
> > + description: an optional pin needed for AK09911 to set the reset state
>
> Maybe add a comment that this should be "usually active low".
>
> > +
> > required:
> > - compatible
> > - reg
> > @@ -53,6 +56,7 @@ examples:
> > reg = <0x0c>;
> > gpios = <&gpj0 7 0>;
> > vdd-supply = <&ldo_3v3_gnss>;
> > + reset-gpio = <&msmgpio 111 1>;
>
> Same here, reset-gpio = <&msmgpio 111 GPIO_ACTIVE_LOW>,
> would be more clear.
>
> > mount-matrix = "-0.984807753012208", /* x0 */
> > "0", /* y0 */
> > "-0.173648177666930", /* z0 */
> > --
> > 2.17.1

Thank you for the suggestions, will work on them,

Best regards,
Jonathan Albrieux