[PATCHv4 0/3] iio: Add a ChromeOS EC MKBP proximity driver

This is a different approach to [1] where I tried to add this proximity
sensor logic to the input subsystem. Instead, we'll take the approach of
making a small IIO proximity driver that parses the EC switch bitmap to
find out if the front proximity sensor is detecting something or not.
This allows us to treat proximity sensors as IIO devices all the time in
userspace instead of handling this switch on the EC via the input
subsystem and then other proximity sensors via IIO.

I propose this is all merged through IIO subsystem. Please ack
the first patch so it can be merged that way.

Changes from v3:
 * Added SPI and cros-ec wrapper nodes to yaml example
 * Ignore notifier registration return code that is always zero

Changes from v2:
 * Check iio clock and use IIO time if not boottime

Changes from v1:
 * Driver moved location
 * Put mkbp everywhere
 * Fixed up DT binding to not fail and make sure is a child of cros-ec
 * Simplified logic for sending a message
 * Dropped CONFIG_OF usage
 * Sorted includes

[1] https://lore.kernel.org/r/20201205004709.3126266-1-swboyd@chromium.org

Cc: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Cc: Benson Leung <bleung@chromium.org>
Cc: Guenter Roeck <groeck@chromium.org>
Cc: Douglas Anderson <dianders@chromium.org>
Cc: Gwendal Grignou <redacted>
Cc: <redacted>
Cc: Rob Herring <robh+dt@kernel.org>
Cc: Enric Balletbo i Serra <redacted>

Stephen Boyd (3):
  platform/chrome: cros_ec: Add SW_FRONT_PROXIMITY MKBP define
  dt-bindings: iio: Add cros ec proximity yaml doc
  iio: proximity: Add a ChromeOS EC MKBP proximity driver

 .../google,cros-ec-mkbp-proximity.yaml        |  46 ++++
 .../bindings/mfd/google,cros-ec.yaml          |   3 +
 drivers/iio/proximity/Kconfig                 |  11 +
 drivers/iio/proximity/Makefile                |   1 +
 .../iio/proximity/cros_ec_mkbp_proximity.c    | 242 ++++++++++++++++++
 .../linux/platform_data/cros_ec_commands.h    |   1 +
 6 files changed, 304 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/iio/proximity/google,cros-ec-mkbp-proximity.yaml
 create mode 100644 drivers/iio/proximity/cros_ec_mkbp_proximity.c


base-commit: 19c329f6808995b142b3966301f217c831e7cf31
-- 
https://chromeos.dev

Some cros ECs support a front proximity MKBP event via
'EC_MKBP_FRONT_PROXIMITY'. Add a DT binding to document this feature via
a node that is a child of the main cros_ec device node. Devices that
have this ability will describe this in firmware.

Cc: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Cc: Benson Leung <bleung@chromium.org>
Cc: Guenter Roeck <groeck@chromium.org>
Cc: Douglas Anderson <dianders@chromium.org>
Cc: Gwendal Grignou <redacted>
Cc: <redacted>
Cc: Rob Herring <robh+dt@kernel.org>
Cc: Enric Balletbo i Serra <redacted>
Signed-off-by: Stephen Boyd <redacted>
---
 .../google,cros-ec-mkbp-proximity.yaml        | 46 +++++++++++++++++++
 .../bindings/mfd/google,cros-ec.yaml          |  3 ++
 2 files changed, 49 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/iio/proximity/google,cros-ec-mkbp-proximity.yaml

diff --git a/Documentation/devicetree/bindings/iio/proximity/google,cros-ec-mkbp-proximity.yaml b/Documentation/devicetree/bindings/iio/proximity/google,cros-ec-mkbp-proximity.yaml
new file mode 100644
index 000000000000..d82b929af445
--- /dev/null
+++ b/Documentation/devicetree/bindings/iio/proximity/google,cros-ec-mkbp-proximity.yaml

@@ -0,0 +1,46 @@
+# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause)
+%YAML 1.2
+---
+
+$id: http://devicetree.org/schemas/iio/proximity/google,cros-ec-mkbp-proximity.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: ChromeOS EC MKBP Proximity Sensor
+
+maintainers:
+  - Stephen Boyd <swboyd@chromium.org>
+  - Benson Leung <bleung@chromium.org>
+  - Enric Balletbo i Serra <enric.balletbo@collabora.com>
+
+description: |
+  Google's ChromeOS EC sometimes has the ability to detect user proximity.
+  This is implemented on the EC as near/far logic and exposed to the OS
+  via an MKBP switch bit.
+
+properties:
+  compatible:
+    const: google,cros-ec-mkbp-proximity
+
+  label:
+    description: Name for proximity sensor
+
+required:
+  - compatible
+
+unevaluatedProperties: false
+additionalProperties: false
+
+examples:
+  - |
+    spi {
+      #address-cells = <1>;
+      #size-cells = <0>;
+      ec@0 {
+        compatible = "google,cros-ec-spi";
+        reg = <0>;
+        proximity {
+          compatible = "google,cros-ec-mkbp-proximity";
+          label = "proximity-wifi-lte";
+        };
+      };
+    };

diff --git a/Documentation/devicetree/bindings/mfd/google,cros-ec.yaml b/Documentation/devicetree/bindings/mfd/google,cros-ec.yaml
index 76bf16ee27ec..479a9f15de32 100644
--- a/Documentation/devicetree/bindings/mfd/google,cros-ec.yaml
+++ b/Documentation/devicetree/bindings/mfd/google,cros-ec.yaml

@@ -94,6 +94,9 @@ properties:
   keyboard-controller:
     $ref: "/schemas/input/google,cros-ec-keyb.yaml#"
 
+  proximity:
+    $ref: "/schemas/iio/proximity/google,cros-ec-mkbp-proximity.yaml#"
+
   codecs:
     type: object
     additionalProperties: false

-- 
https://chromeos.dev

Hi Stephen,

Missatge de Stephen Boyd [off-list ref] del dia dt., 2 de febr.
2021 a les 19:53:

Some cros ECs support a front proximity MKBP event via
'EC_MKBP_FRONT_PROXIMITY'. Add a DT binding to document this feature via
a node that is a child of the main cros_ec device node. Devices that
have this ability will describe this in firmware.

Cc: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Cc: Benson Leung <bleung@chromium.org>
Cc: Guenter Roeck <groeck@chromium.org>
Cc: Douglas Anderson <dianders@chromium.org>
Cc: Gwendal Grignou <redacted>
Cc: <redacted>
Cc: Rob Herring <robh+dt@kernel.org>
Cc: Enric Balletbo i Serra <redacted>
Signed-off-by: Stephen Boyd <redacted>

Thanks for adding a full example, IIRC this is preferred by Rob and we
are also trying to apply this rule on all the cros-ec related
bindings, so the dt_bindings_check really checks a full example. From
my side looks good to me.

Reviewed-by: Enric Balletbo i Serra <redacted>

On Tue, Feb 02, 2021 at 10:44:33AM -0800, Stephen Boyd wrote:

Only need one. In this case 'additionalProperties'.

+
+examples:
+  - |
+    spi {
+      #address-cells = <1>;
+      #size-cells = <0>;
+      ec@0 {
+        compatible = "google,cros-ec-spi";
+        reg = <0>;
+        proximity {
+          compatible = "google,cros-ec-mkbp-proximity";
+          label = "proximity-wifi-lte";
+        };

The complete examples I prefer is 1 example for the whole MFD in the MFD 
schema and no example here.

Quoting Rob Herring (2021-02-09 13:13:47)

On Tue, Feb 02, 2021 at 10:44:33AM -0800, Stephen Boyd wrote:

quoted

+    description: Name for proximity sensor
+
+required:
+  - compatible
+
+unevaluatedProperties: false
+additionalProperties: false

Only need one. In this case 'additionalProperties'.

Got it.

quoted

+
+examples:
+  - |
+    spi {
+      #address-cells = <1>;
+      #size-cells = <0>;
+      ec@0 {
+        compatible = "google,cros-ec-spi";
+        reg = <0>;
+        proximity {
+          compatible = "google,cros-ec-mkbp-proximity";
+          label = "proximity-wifi-lte";
+        };

The complete examples I prefer is 1 example for the whole MFD in the MFD 
schema and no example here.

Alright. I can add it to the mfd binding instead.

quoted

+      };
+    };

diff --git a/Documentation/devicetree/bindings/mfd/google,cros-ec.yaml b/Documentation/devicetree/bindings/mfd/google,cros-ec.yaml
index 76bf16ee27ec..479a9f15de32 100644
--- a/Documentation/devicetree/bindings/mfd/google,cros-ec.yaml
+++ b/Documentation/devicetree/bindings/mfd/google,cros-ec.yaml

@@ -94,6 +94,9 @@ properties:
   keyboard-controller:
     $ref: "/schemas/input/google,cros-ec-keyb.yaml#"