diff mbox series

[v6,2/2] dt-bindings: cros-ec: Add ChromeOS fingerprint binding

Message ID 20220614195144.2794796-3-swboyd@chromium.org (mailing list archive)
State New, archived
Headers show
Series dt-bindings: cros-ec: Update for fingerprint devices | expand

Commit Message

Stephen Boyd June 14, 2022, 7:51 p.m. UTC
Add a binding to describe the fingerprint processor found on Chromebooks
with a fingerprint sensor. Previously we've been describing this with
the google,cros-ec-spi binding but it lacks gpio and regulator control
used during firmware flashing.

Cc: Rob Herring <robh+dt@kernel.org>
Cc: Krzysztof Kozlowski <krzysztof.kozlowski+dt@linaro.org>
Cc: <devicetree@vger.kernel.org>
Cc: <chrome-platform@lists.linux.dev>
Cc: Guenter Roeck <groeck@chromium.org>
Cc: Douglas Anderson <dianders@chromium.org>
Cc: Craig Hesling <hesling@chromium.org>
Cc: Tom Hughes <tomhughes@chromium.org>
Cc: Alexandru M Stan <amstan@chromium.org>
Cc: Tzung-Bi Shih <tzungbi@kernel.org>
Cc: Matthias Kaehlcke <mka@chromium.org>
Cc: Benson Leung <bleung@chromium.org>
Cc: Lee Jones <lee.jones@linaro.org>
Signed-off-by: Stephen Boyd <swboyd@chromium.org>
---
 .../bindings/chrome/google,cros-ec-fp.yaml    | 97 +++++++++++++++++++
 .../bindings/mfd/google,cros-ec.yaml          |  9 ++
 2 files changed, 106 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/chrome/google,cros-ec-fp.yaml

Comments

Doug Anderson June 14, 2022, 10:41 p.m. UTC | #1
Hi,

On Tue, Jun 14, 2022 at 12:51 PM Stephen Boyd <swboyd@chromium.org> wrote:
>
> Add a binding to describe the fingerprint processor found on Chromebooks
> with a fingerprint sensor. Previously we've been describing this with
> the google,cros-ec-spi binding but it lacks gpio and regulator control
> used during firmware flashing.
>
> Cc: Rob Herring <robh+dt@kernel.org>
> Cc: Krzysztof Kozlowski <krzysztof.kozlowski+dt@linaro.org>
> Cc: <devicetree@vger.kernel.org>
> Cc: <chrome-platform@lists.linux.dev>
> Cc: Guenter Roeck <groeck@chromium.org>
> Cc: Douglas Anderson <dianders@chromium.org>
> Cc: Craig Hesling <hesling@chromium.org>
> Cc: Tom Hughes <tomhughes@chromium.org>
> Cc: Alexandru M Stan <amstan@chromium.org>
> Cc: Tzung-Bi Shih <tzungbi@kernel.org>
> Cc: Matthias Kaehlcke <mka@chromium.org>
> Cc: Benson Leung <bleung@chromium.org>
> Cc: Lee Jones <lee.jones@linaro.org>
> Signed-off-by: Stephen Boyd <swboyd@chromium.org>
> ---
>  .../bindings/chrome/google,cros-ec-fp.yaml    | 97 +++++++++++++++++++
>  .../bindings/mfd/google,cros-ec.yaml          |  9 ++
>  2 files changed, 106 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/chrome/google,cros-ec-fp.yaml
>
> diff --git a/Documentation/devicetree/bindings/chrome/google,cros-ec-fp.yaml b/Documentation/devicetree/bindings/chrome/google,cros-ec-fp.yaml
> new file mode 100644
> index 000000000000..48c02bd4585c
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/chrome/google,cros-ec-fp.yaml
> @@ -0,0 +1,97 @@
> +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
> +%YAML 1.2
> +---
> +$id: http://devicetree.org/schemas/chrome/google,cros-ec-fp.yaml#
> +$schema: http://devicetree.org/meta-schemas/core.yaml#
> +
> +title: ChromeOS Embedded Fingerprint Controller
> +
> +description:
> +  Google's ChromeOS embedded fingerprint controller is a device which
> +  implements fingerprint functionality such as unlocking a Chromebook
> +  without typing a password.
> +
> +maintainers:
> +  - Tom Hughes <tomhughes@chromium.org>
> +
> +select:
> +  properties:
> +    compatible:
> +      contains:
> +        const: google,cros-ec-spi
> +  required:
> +    - compatible
> +    - boot0-gpios

I've never personally used "select" before and I'm not sure where it's
documented. Without knowing anything, it seems weird to me that in
this file we're matching against a compatible that's not
google,cros-ec-fp. Randomly grabbing some other example that's similar
(panel-lvds.yaml) looks more like what I would have expected. AKA in
this file:

select:
  properties:
    compatible:
      contains:
        const: google,cros-ec-fp
  required:
    - compatible

...and then in the other file:

select:
  properties:
    compatible:
      contains:
        const: google,cros-ec-spi
  not:
    properties:
      compatible:
        contains:
          const: google,cros-ec-fp
  required:
    - compatible


Of course, if one of the dt maintainers gives different advice then
listen to them. ;-)

-Doug
Stephen Boyd June 16, 2022, 12:50 a.m. UTC | #2
Quoting Doug Anderson (2022-06-14 15:41:25)
> On Tue, Jun 14, 2022 at 12:51 PM Stephen Boyd <swboyd@chromium.org> wrote:
> > +
> > +select:
> > +  properties:
> > +    compatible:
> > +      contains:
> > +        const: google,cros-ec-spi
> > +  required:
> > +    - compatible
> > +    - boot0-gpios
>
> I've never personally used "select" before and I'm not sure where it's
> documented. Without knowing anything, it seems weird to me that in
> this file we're matching against a compatible that's not
> google,cros-ec-fp. Randomly grabbing some other example that's similar
> (panel-lvds.yaml) looks more like what I would have expected. AKA in
> this file:
>
> select:
>   properties:
>     compatible:
>       contains:
>         const: google,cros-ec-fp
>   required:
>     - compatible
>
> ...and then in the other file:
>
> select:
>   properties:
>     compatible:
>       contains:
>         const: google,cros-ec-spi
>   not:
>     properties:
>       compatible:
>         contains:
>           const: google,cros-ec-fp
>   required:
>     - compatible
>
>
> Of course, if one of the dt maintainers gives different advice then
> listen to them. ;-)
>

I followed a pwm example, see renesas,tpu-pwm.yaml, but I suspect this
works just as well. I don't really care either way so I'll defer to DT
maintainers here.
Rob Herring June 27, 2022, 9:57 p.m. UTC | #3
On Tue, Jun 14, 2022 at 03:41:25PM -0700, Doug Anderson wrote:
> Hi,
> 
> On Tue, Jun 14, 2022 at 12:51 PM Stephen Boyd <swboyd@chromium.org> wrote:
> >
> > Add a binding to describe the fingerprint processor found on Chromebooks
> > with a fingerprint sensor. Previously we've been describing this with
> > the google,cros-ec-spi binding but it lacks gpio and regulator control
> > used during firmware flashing.
> >
> > Cc: Rob Herring <robh+dt@kernel.org>
> > Cc: Krzysztof Kozlowski <krzysztof.kozlowski+dt@linaro.org>
> > Cc: <devicetree@vger.kernel.org>
> > Cc: <chrome-platform@lists.linux.dev>
> > Cc: Guenter Roeck <groeck@chromium.org>
> > Cc: Douglas Anderson <dianders@chromium.org>
> > Cc: Craig Hesling <hesling@chromium.org>
> > Cc: Tom Hughes <tomhughes@chromium.org>
> > Cc: Alexandru M Stan <amstan@chromium.org>
> > Cc: Tzung-Bi Shih <tzungbi@kernel.org>
> > Cc: Matthias Kaehlcke <mka@chromium.org>
> > Cc: Benson Leung <bleung@chromium.org>
> > Cc: Lee Jones <lee.jones@linaro.org>
> > Signed-off-by: Stephen Boyd <swboyd@chromium.org>
> > ---
> >  .../bindings/chrome/google,cros-ec-fp.yaml    | 97 +++++++++++++++++++
> >  .../bindings/mfd/google,cros-ec.yaml          |  9 ++
> >  2 files changed, 106 insertions(+)
> >  create mode 100644 Documentation/devicetree/bindings/chrome/google,cros-ec-fp.yaml
> >
> > diff --git a/Documentation/devicetree/bindings/chrome/google,cros-ec-fp.yaml b/Documentation/devicetree/bindings/chrome/google,cros-ec-fp.yaml
> > new file mode 100644
> > index 000000000000..48c02bd4585c
> > --- /dev/null
> > +++ b/Documentation/devicetree/bindings/chrome/google,cros-ec-fp.yaml
> > @@ -0,0 +1,97 @@
> > +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
> > +%YAML 1.2
> > +---
> > +$id: http://devicetree.org/schemas/chrome/google,cros-ec-fp.yaml#
> > +$schema: http://devicetree.org/meta-schemas/core.yaml#
> > +
> > +title: ChromeOS Embedded Fingerprint Controller
> > +
> > +description:
> > +  Google's ChromeOS embedded fingerprint controller is a device which
> > +  implements fingerprint functionality such as unlocking a Chromebook
> > +  without typing a password.
> > +
> > +maintainers:
> > +  - Tom Hughes <tomhughes@chromium.org>
> > +
> > +select:
> > +  properties:
> > +    compatible:
> > +      contains:
> > +        const: google,cros-ec-spi
> > +  required:
> > +    - compatible
> > +    - boot0-gpios
> 
> I've never personally used "select" before and I'm not sure where it's
> documented. 

Documentation/devicetree/bindings/writing-schema.rst

> Without knowing anything, it seems weird to me that in
> this file we're matching against a compatible that's not
> google,cros-ec-fp. Randomly grabbing some other example that's similar
> (panel-lvds.yaml) looks more like what I would have expected. AKA in
> this file:
> 
> select:
>   properties:
>     compatible:
>       contains:
>         const: google,cros-ec-fp
>   required:
>     - compatible
> 
> ...and then in the other file:
> 
> select:
>   properties:
>     compatible:
>       contains:
>         const: google,cros-ec-spi

What about i2c and rpmsg variants?

>   not:
>     properties:
>       compatible:
>         contains:
>           const: google,cros-ec-fp
>   required:
>     - compatible

That is what is needed assuming the binding stands as-is. Otherwise, 
boot0-gpios erroneously present or missing will give unexpected results.

If we were starting from scratch, I would say you should just drop 
'google,cros-ec-spi' from this binding. But I guess you want to preserve 
compatibility here. In that case, I think all this should be added to 
the existing doc with an if/then schema for conditional parts. That also 
avoids defining the common properties twice or moving them to a common, 
shared schema.

Rob
Stephen Boyd June 29, 2022, 7:29 a.m. UTC | #4
Quoting Rob Herring (2022-06-27 14:57:20)
>
> If we were starting from scratch, I would say you should just drop
> 'google,cros-ec-spi' from this binding. But I guess you want to preserve
> compatibility here. In that case, I think all this should be added to
> the existing doc with an if/then schema for conditional parts. That also
> avoids defining the common properties twice or moving them to a common,
> shared schema.
>

I had it all combined in a previous version. Let me see if I can merge
the two together (again) and fix the bugs.
diff mbox series

Patch

diff --git a/Documentation/devicetree/bindings/chrome/google,cros-ec-fp.yaml b/Documentation/devicetree/bindings/chrome/google,cros-ec-fp.yaml
new file mode 100644
index 000000000000..48c02bd4585c
--- /dev/null
+++ b/Documentation/devicetree/bindings/chrome/google,cros-ec-fp.yaml
@@ -0,0 +1,97 @@ 
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/chrome/google,cros-ec-fp.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: ChromeOS Embedded Fingerprint Controller
+
+description:
+  Google's ChromeOS embedded fingerprint controller is a device which
+  implements fingerprint functionality such as unlocking a Chromebook
+  without typing a password.
+
+maintainers:
+  - Tom Hughes <tomhughes@chromium.org>
+
+select:
+  properties:
+    compatible:
+      contains:
+        const: google,cros-ec-spi
+  required:
+    - compatible
+    - boot0-gpios
+
+allOf:
+  - $ref: /schemas/spi/spi-peripheral-props.yaml#
+
+properties:
+  compatible:
+    items:
+      - const: google,cros-ec-fp
+      - const: google,cros-ec-spi
+
+  reg:
+    maxItems: 1
+
+  interrupts:
+    maxItems: 1
+
+  controller-data: true
+
+  google,cros-ec-spi-pre-delay:
+    description:
+      This property specifies the delay in usecs between the
+      assertion of the CS and the first clock pulse.
+    $ref: /schemas/types.yaml#/definitions/uint32
+    default: 0
+
+  google,cros-ec-spi-msg-delay:
+    description:
+      This property specifies the delay in usecs between messages.
+    $ref: /schemas/types.yaml#/definitions/uint32
+    default: 0
+
+  spi-max-frequency:
+    maximum: 3000000
+
+  reset-gpios:
+    maxItems: 1
+
+  boot0-gpios:
+    maxItems: 1
+    description: Assert for bootloader mode.
+
+  vdd-supply: true
+
+required:
+  - compatible
+  - reg
+  - interrupts
+  - reset-gpios
+  - boot0-gpios
+  - vdd-supply
+
+additionalProperties: false
+
+examples:
+  - |
+    #include <dt-bindings/interrupt-controller/irq.h>
+    #include <dt-bindings/gpio/gpio.h>
+    spi0 {
+      #address-cells = <0x1>;
+      #size-cells = <0x0>;
+
+      ec@0 {
+        compatible = "google,cros-ec-fp", "google,cros-ec-spi";
+        reg = <0x0>;
+        interrupt-parent = <&gpio_controller>;
+        interrupts = <4 IRQ_TYPE_LEVEL_LOW>;
+        spi-max-frequency = <3000000>;
+        reset-gpios = <&gpio_controller 5 GPIO_ACTIVE_LOW>;
+        boot0-gpios = <&gpio_controller 10 GPIO_ACTIVE_HIGH>;
+        vdd-supply = <&pp3300_fp_mcu>;
+      };
+    };
+...
diff --git a/Documentation/devicetree/bindings/mfd/google,cros-ec.yaml b/Documentation/devicetree/bindings/mfd/google,cros-ec.yaml
index 178e26ab115c..a7453bbd7bed 100644
--- a/Documentation/devicetree/bindings/mfd/google,cros-ec.yaml
+++ b/Documentation/devicetree/bindings/mfd/google,cros-ec.yaml
@@ -10,6 +10,15 @@  maintainers:
   - Benson Leung <bleung@chromium.org>
   - Guenter Roeck <groeck@chromium.org>
 
+select:
+  properties:
+    compatible:
+      contains:
+        const: google,cros-ec-spi
+    boot0-gpios: false
+  required:
+    - compatible
+
 description:
   Google's ChromeOS EC is a microcontroller which talks to the AP and
   implements various functions such as keyboard and battery charging.