diff mbox series

[v6,3/5] dt-bindings: iio: magnetometer: ak8975: add gpio reset support

Message ID 20200525151117.32540-4-jonathan.albrieux@gmail.com (mailing list archive)
State New, archived
Headers show
Series iio: magnetometer: ak8975: Add gpio reset support | expand

Commit Message

Jonathan Albrieux May 25, 2020, 3:10 p.m. UTC
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 datasheet says that, if not used, reset pin should be connected
to VID. This patch emulates this situation.

Signed-off-by: Jonathan Albrieux <jonathan.albrieux@gmail.com>
---
 .../bindings/iio/magnetometer/asahi-kasei,ak8975.yaml      | 7 +++++++
 1 file changed, 7 insertions(+)

Comments

Linus Walleij May 26, 2020, 9:22 a.m. UTC | #1
On Mon, May 25, 2020 at 5:13 PM Jonathan Albrieux
<jonathan.albrieux@gmail.com> 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 datasheet says that, if not used, reset pin should be connected
> to VID. This patch emulates this situation.
>
> Signed-off-by: Jonathan Albrieux <jonathan.albrieux@gmail.com>

Reviewed-by: Linus Walleij <linus.walleij@linaro.org>

Yours,
Linus Walleij
Jonathan Albrieux May 26, 2020, 5:11 p.m. UTC | #2
On Tue, May 26, 2020 at 11:22:07AM +0200, Linus Walleij wrote:
> On Mon, May 25, 2020 at 5:13 PM Jonathan Albrieux
> <jonathan.albrieux@gmail.com> 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 datasheet says that, if not used, reset pin should be connected
> > to VID. This patch emulates this situation.
> >
> > Signed-off-by: Jonathan Albrieux <jonathan.albrieux@gmail.com>
> 
> Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
> 
> Yours,
> Linus Walleij

Thank you!!

Best regards,
Jonathan Albrieux
Rob Herring (Arm) May 26, 2020, 10:29 p.m. UTC | #3
On Mon, 25 May 2020 17:10:37 +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 datasheet says that, if not used, reset pin should be connected
> to VID. This patch emulates this situation.
> 
> Signed-off-by: Jonathan Albrieux <jonathan.albrieux@gmail.com>
> ---
>  .../bindings/iio/magnetometer/asahi-kasei,ak8975.yaml      | 7 +++++++
>  1 file changed, 7 insertions(+)
> 

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

Patch

diff --git a/Documentation/devicetree/bindings/iio/magnetometer/asahi-kasei,ak8975.yaml b/Documentation/devicetree/bindings/iio/magnetometer/asahi-kasei,ak8975.yaml
index a603659d5fa5..04b895c7143c 100644
--- a/Documentation/devicetree/bindings/iio/magnetometer/asahi-kasei,ak8975.yaml
+++ b/Documentation/devicetree/bindings/iio/magnetometer/asahi-kasei,ak8975.yaml
@@ -48,6 +48,11 @@  properties:
   mount-matrix:
     description: an optional 3x3 mounting rotation matrix.
 
+  reset-gpios:
+    description: |
+      an optional pin needed for AK09911 to set the reset state. This should
+      be usually active low
+
 required:
   - compatible
   - reg
@@ -55,6 +60,7 @@  required:
 examples:
   - |
     #include <dt-bindings/interrupt-controller/irq.h>
+    #include <dt-bindings/gpio/gpio.h>
     i2c {
         #address-cells = <1>;
         #size-cells = <0>;
@@ -65,6 +71,7 @@  examples:
             interrupt-parent = <&gpio6>;
             interrupts = <15 IRQ_TYPE_EDGE_RISING>;
             vdd-supply = <&ldo_3v3_gnss>;
+            reset-gpios = <&msmgpio 111 GPIO_ACTIVE_LOW>;
             mount-matrix = "-0.984807753012208",  /* x0 */
                            "0",                   /* y0 */
                            "-0.173648177666930",  /* z0 */