iio: vcnl4000: Export near level property for proximity sensor

Introduce a file for common properties of iio sensors. So far this contains the new proximity-near-level property for proximity sensors that indicates when an object should be considered near.

Signed-off-by Guido Günther <[email protected]>

---
 .../devicetree/bindings/iio/common.yaml       | 35 +++++++++++++++++++
 1 file changed, 35 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/iio/common.yaml

Documentation/devicetree/bindings/iio/common.yaml new file +35 -0

new file mode 100644
index 000000000000..97ffcb77043d
@@ -0,0 +1,35 @@
+# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/iio/common.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Common properties for iio sensors
+
+maintainers:
+  - Jonathan Cameron <[email protected]>
+  - Guido Günther <[email protected]>
+
+description: |
+  This document defines device tree properties common to several iio
+  sensors. It doesn't constitue a device tree binding specification by itself but
+  is meant to be referenced by device tree bindings.
+
+  When referenced from sensor tree bindings the properties defined in this
+  document are defined as follows. The sensor tree bindings are responsible for
+  defining whether each property is required or optional.
+
+properties:
+  proximity-near-level:
+    $ref: /schemas/types.yaml#/definitions/uint32
+    description: |
+      For proximity sensors whether an object can be considered near to the
+      device depends on parameters like sensor position, covering glass and
+      aperture. This value gives an indication to userspace for which
+      sensor readings this is the case.
+
+      Raw proximity values equal or above this level should be
+      considered 'near' to the device (an object is near to the
+      sensor).
+
+...

Introduce a file for common properties of iio sensors. So far this contains the new proximity-near-level property for proximity sensors that indicates when an object should be considered near.

Signed-off-by Guido Günther <[email protected]>

---
 .../devicetree/bindings/iio/common.yaml       | 35 +++++++++++++++++++
 1 file changed, 35 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/iio/common.yaml

Quoted 4 lines · On Sun, 5 Apr 2020 15:50:29 +0200, =?UTF-8?q?Guido=20G=C3=BCnther?= wrote:

Introduce a file for common properties of iio sensors. So far this contains the new proximity-near-level property for proximity sensors that indicates when an object should be considered near.

Quoted 6 lines

Signed-off-by Guido Günther <[email protected]>

---
 .../devicetree/bindings/iio/common.yaml       | 35 +++++++++++++++++++
 1 file changed, 35 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/iio/common.yaml

Reviewed-by Rob Herring <[email protected]>

This value indicates when userspace should consider an object near to the sensor/device.

Signed-off-by Guido Günther <[email protected]>

---
 .../devicetree/bindings/iio/light/vishay,vcnl4000.yaml     | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

Quoted 8 lines · On Sun, 5 Apr 2020 15:50:30 +0200, =?UTF-8?q?Guido=20G=C3=BCnther?= wrote:

This value indicates when userspace should consider an object near to the sensor/device.

Signed-off-by Guido Günther <[email protected]>

---
 .../devicetree/bindings/iio/light/vishay,vcnl4000.yaml     | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

Reviewed-by Rob Herring <[email protected]>

When an object can be considered close to the sensor is hardware dependent. Allowing to configure the property via device tree allows to configure this device specific value.

This is useful for e.g. iio-sensor-proxy to indicate to userspace if an object is close to the sensor.

Signed-off-by Guido Günther <[email protected]>

---
 drivers/iio/light/vcnl4000.c | 25 +++++++++++++++++++++++++
 1 file changed, 25 insertions(+)

drivers/iio/light/vcnl4000.c +25 -0

index ec803c1e81df..985cc39ede8e 100644
@@ -83,6 +83,7 @@ struct vcnl4000_data {
 	struct mutex vcnl4000_lock;
 	struct vcnl4200_channel vcnl4200_al;
 	struct vcnl4200_channel vcnl4200_ps;
+	uint32_t near_level;
 };
 
 struct vcnl4000_chip_spec {

@@ -343,6 +344,25 @@ static const struct vcnl4000_chip_spec vcnl4000_chip_spec_cfg[] = {
 	},
 };
 
+static ssize_t vcnl4000_read_near_level(struct iio_dev *indio_dev,
+					uintptr_t priv,
+					const struct iio_chan_spec *chan,
+					char *buf)
+{
+	struct vcnl4000_data *data = iio_priv(indio_dev);
+
+	return sprintf(buf, "%u\n", data->near_level);
+}
+
+static const struct iio_chan_spec_ext_info vcnl4000_ext_info[] = {
+	{
+		.name = "nearlevel",
+		.shared = IIO_SEPARATE,
+		.read = vcnl4000_read_near_level,
+	},
+	{ /* sentinel */ }
+};
+
 static const struct iio_chan_spec vcnl4000_channels[] = {
 	{
 		.type = IIO_LIGHT,

@@ -351,6 +371,7 @@ static const struct iio_chan_spec vcnl4000_channels[] = {
 	}, {
 		.type = IIO_PROXIMITY,
 		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
+		.ext_info = vcnl4000_ext_info,
 	}
 };
 

@@ -440,6 +461,10 @@ static int vcnl4000_probe(struct i2c_client *client,
 	dev_dbg(&client->dev, "%s Ambient light/proximity sensor, Rev: %02x\n",
 		data->chip_spec->prod, data->rev);
 
+	if (device_property_read_u32(&client->dev, "proximity-near-level",
+				     &data->near_level))
+		data->near_level = 0;
+
 	indio_dev->dev.parent = &client->dev;
 	indio_dev->info = &vcnl4000_info;
 	indio_dev->channels = vcnl4000_channels;

The vcnl4000 IIO driver introduced a new attribute "in_proximity_nearlevel". This adds it to the list of documented ABI for sysfs-bus-iio.

Signed-off-by Guido Günther <[email protected]>

---
 Documentation/ABI/testing/sysfs-bus-iio-proximity | 10 ++++++++++
 1 file changed, 10 insertions(+)
 create mode 100644 Documentation/ABI/testing/sysfs-bus-iio-proximity

Documentation/ABI/testing/sysfs-bus-iio-proximity new file +10 -0

new file mode 100644
index 000000000000..2172f3bb9c64
@@ -0,0 +1,10 @@
+What:		/sys/bus/iio/devices/iio:deviceX/in_proximity_nearlevel
+Date:		March 2020
+KernelVersion:	5.7
+Contact:	[email protected]
+Description:
+		Near level for proximity sensors. This is a single integer
+		value that tells user space when an object should be
+		considered close to the device. If the value read from the
+		sensor is above or equal to the value in this file an object
+		should typically be considered near.