[v3,2/3] dt-bindings: gnss: u-blox: add "reset-gpios" binding

Commit Message

Wolfram Sang Sept. 21, 2023, 1:32 p.m. UTC

Needed to enable this chip on a Renesas KingFisher board. Description
copied over from the Mediatek driver which already supports it.

Signed-off-by: Wolfram Sang <[e-mail]>
Acked-by: Conor Dooley <[e-mail]>
Reviewed-by: Geert Uytterhoeven <[e-mail]>
---
 Documentation/devicetree/bindings/gnss/u-blox,neo-6m.yaml | 5 +++++
 1 file changed, 5 insertions(+)

Comments

Johan Hovold Oct. 16, 2023, 1:43 p.m. UTC | #1

On Thu, Sep 21, 2023 at 03:32:00PM +0200, Wolfram Sang wrote:
> Needed to enable this chip on a Renesas KingFisher board.

What is needed? Please make the commit message self-contained.

And what GNSS chip/module is this? This should also be included in the
commit message.

Do you have a link to a datasheet?

None of the u-blox modules I've seen have a reset line so I'd like to
where this came from and how it is intended to be used.

> Description
> copied over from the Mediatek driver which already supports it.

The mediatek driver does not support managing a reset line, but the
binding includes a description of this pin for completeness. Also you
don't seem include any description of the property below (which is fine)
so perhaps you can just drop this sentence.

Johan

Wolfram Sang Oct. 23, 2023, 6:52 a.m. UTC | #2

Hi Johan,

> And what GNSS chip/module is this? This should also be included in the
> commit message.

Ok. UBlox Neo-M8.

> Do you have a link to a datasheet?

https://www.u-blox.com/sites/default/files/NEO-M8-FW3_DataSheet_UBX-15031086.pdf

> None of the u-blox modules I've seen have a reset line so I'd like to
> where this came from and how it is intended to be used.

I didn't know that old modules did not have the reset pin. I thought
they were simply not used, so far. This one has. Check pin8 in chapter
2.1 in the datasheet.

> The mediatek driver does not support managing a reset line, but the
> binding includes a description of this pin for completeness. Also you
> don't seem include any description of the property below (which is fine)
> so perhaps you can just drop this sentence.

Correct.

Kind regards,

   Wolfram

Johan Hovold Nov. 6, 2023, 2:14 p.m. UTC | #3

On Mon, Oct 23, 2023 at 08:52:25AM +0200, Wolfram Sang wrote:
> > And what GNSS chip/module is this? This should also be included in the
> > commit message.
> 
> Ok. UBlox Neo-M8.
> 
> > Do you have a link to a datasheet?
> 
> https://www.u-blox.com/sites/default/files/NEO-M8-FW3_DataSheet_UBX-15031086.pdf
> 
> > None of the u-blox modules I've seen have a reset line so I'd like to
> > where this came from and how it is intended to be used.
> 
> I didn't know that old modules did not have the reset pin. I thought
> they were simply not used, so far. This one has. Check pin8 in chapter
> 2.1 in the datasheet.

Indeed. I must have looked at the datasheet of the older neo-6, which
does not have a reset pin, before replying.

Johan

Patch

diff --git a/Documentation/devicetree/bindings/gnss/u-blox,neo-6m.yaml b/Documentation/devicetree/bindings/gnss/u-blox,neo-6m.yaml
index 4835a280b3bf..8e97e475613f 100644
--- a/Documentation/devicetree/bindings/gnss/u-blox,neo-6m.yaml
+++ b/Documentation/devicetree/bindings/gnss/u-blox,neo-6m.yaml
@@ -41,6 +41,9 @@  properties:
     description: >
       Backup voltage regulator
 
+  reset-gpios:
+    maxItems: 1
+
 required:
   - compatible
   - vcc-supply
@@ -49,10 +52,12 @@  unevaluatedProperties: false
 
 examples:
   - |
+    #include <dt-bindings/gpio/gpio.h>
     serial {
         gnss {
             compatible = "u-blox,neo-8";
             v-bckp-supply = <&gnss_v_bckp_reg>;
             vcc-supply = <&gnss_vcc_reg>;
+            reset-gpios = <&gpio 1 GPIO_ACTIVE_LOW>;
         };
     };