[PATCH v6 0/3] iio: Add a ChromeOS EC MKBP proximity driver

[PATCH v6 0/3] iio: Add a ChromeOS EC MKBP proximity driver

[Stephen Boyd]

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 v5:
 * Picked up RB tag from Rob
 * Track state of switch and only push event if it's different

Changes from v4:
 * Reduced binding and moved proximity node to mfd spi example
 * Dropped of_match_ptr()

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 <gwendal@chromium.org>
Cc: <devicetree@vger.kernel.org>
Cc: Rob Herring <robh+dt@kernel.org>
Cc: Enric Balletbo i Serra <enric.balletbo@collabora.com>

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        |  37 +++
 .../bindings/mfd/google,cros-ec.yaml          |   7 +
 drivers/iio/proximity/Kconfig                 |  11 +
 drivers/iio/proximity/Makefile                |   1 +
 .../iio/proximity/cros_ec_mkbp_proximity.c    | 271 ++++++++++++++++++
 .../linux/platform_data/cros_ec_commands.h    |   1 +
 6 files changed, 328 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

[PATCH v6 1/3] platform/chrome: cros_ec: Add SW_FRONT_PROXIMITY MKBP define

[Stephen Boyd]

Some cros ECs support a front proximity MKBP event via
'EC_MKBP_FRONT_PROXIMITY'. Add this define so it can be used in a
future patch.

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 <gwendal@chromium.org>
Acked-by: Enric Balletbo i Serra <enric.balletbo@collabora.com>
Signed-off-by: Stephen Boyd <swboyd@chromium.org>
---
 include/linux/platform_data/cros_ec_commands.h | 1 +
 1 file changed, 1 insertion(+)

diff --git a/include/linux/platform_data/cros_ec_commands.h b/include/linux/platform_data/cros_ec_commands.h
index 86376779ab31..776e0b2be0e9 100644
--- a/include/linux/platform_data/cros_ec_commands.h
+++ b/include/linux/platform_data/cros_ec_commands.h
@@ -3457,6 +3457,7 @@ struct ec_response_get_next_event_v1 {
 #define EC_MKBP_LID_OPEN	0
 #define EC_MKBP_TABLET_MODE	1
 #define EC_MKBP_BASE_ATTACHED	2
+#define EC_MKBP_FRONT_PROXIMITY	3
 
 /* Run keyboard factory test scanning */
 #define EC_CMD_KEYBOARD_FACTORY_TEST 0x0068
-- 
https://chromeos.dev

[PATCH v6 2/3] dt-bindings: iio: Add cros ec proximity yaml doc

[Stephen Boyd]

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 <gwendal@chromium.org>
Cc: <devicetree@vger.kernel.org>
Reviewed-by: Rob Herring <robh@kernel.org>
Cc: Enric Balletbo i Serra <enric.balletbo@collabora.com>
Signed-off-by: Stephen Boyd <swboyd@chromium.org>
---
 .../google,cros-ec-mkbp-proximity.yaml        | 37 +++++++++++++++++++
 .../bindings/mfd/google,cros-ec.yaml          |  7 ++++
 2 files changed, 44 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..099b4be927d4
--- /dev/null
+++ b/Documentation/devicetree/bindings/iio/proximity/google,cros-ec-mkbp-proximity.yaml
@@ -0,0 +1,37 @@
+# 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
+
+additionalProperties: false
+
+examples:
+  - |
+    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..4dfa70a013ae 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
@@ -180,6 +183,10 @@ examples:
             interrupts = <99 0>;
             interrupt-parent = <&gpio7>;
             spi-max-frequency = <5000000>;
+
+            proximity {
+                    compatible = "google,cros-ec-mkbp-proximity";
+            };
         };
     };
 
-- 
https://chromeos.dev

[PATCH v6 3/3] iio: proximity: Add a ChromeOS EC MKBP proximity driver

[Stephen Boyd]

Add support for a ChromeOS EC proximity driver that exposes a "front"
proximity sensor via the IIO subsystem. The EC decides when front
proximity is near and sets an MKBP switch 'EC_MKBP_FRONT_PROXIMITY' to
notify the kernel of proximity. Similarly, when proximity detects
something far away it sets the switch bit to 0. For now this driver
exposes a single sensor, but it could be expanded in the future via more
MKBP bits if desired.

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 <gwendal@chromium.org>
Reviewed-by: Enric Balletbo i Serra <enric.balletbo@collabora.com>
Signed-off-by: Stephen Boyd <swboyd@chromium.org>
---

Changes from v5:
 * Only push event if it's different
 * Check switch on resume

 drivers/iio/proximity/Kconfig                 |  11 +
 drivers/iio/proximity/Makefile                |   1 +
 .../iio/proximity/cros_ec_mkbp_proximity.c    | 271 ++++++++++++++++++
 3 files changed, 283 insertions(+)
 create mode 100644 drivers/iio/proximity/cros_ec_mkbp_proximity.c

diff --git a/drivers/iio/proximity/Kconfig b/drivers/iio/proximity/Kconfig
index 12672a0e89ed..7c7203ca3ac6 100644
--- a/drivers/iio/proximity/Kconfig
+++ b/drivers/iio/proximity/Kconfig
@@ -21,6 +21,17 @@ endmenu
 
 menu "Proximity and distance sensors"
 
+config CROS_EC_MKBP_PROXIMITY
+	tristate "ChromeOS EC MKBP Proximity sensor"
+	depends on CROS_EC
+	help
+	  Say Y here to enable the proximity sensor implemented via the ChromeOS EC MKBP
+	  switches protocol. You must enable one bus option (CROS_EC_I2C or CROS_EC_SPI)
+	  to use this.
+
+	  To compile this driver as a module, choose M here: the
+	  module will be called cros_ec_mkbp_proximity.
+
 config ISL29501
 	tristate "Intersil ISL29501 Time Of Flight sensor"
 	depends on I2C
diff --git a/drivers/iio/proximity/Makefile b/drivers/iio/proximity/Makefile
index 9c1aca1a8b79..cbdac09433eb 100644
--- a/drivers/iio/proximity/Makefile
+++ b/drivers/iio/proximity/Makefile
@@ -5,6 +5,7 @@
 
 # When adding new entries keep the list in alphabetical order
 obj-$(CONFIG_AS3935)		+= as3935.o
+obj-$(CONFIG_CROS_EC_MKBP_PROXIMITY) += cros_ec_mkbp_proximity.o
 obj-$(CONFIG_ISL29501)		+= isl29501.o
 obj-$(CONFIG_LIDAR_LITE_V2)	+= pulsedlight-lidar-lite-v2.o
 obj-$(CONFIG_MB1232)		+= mb1232.o
diff --git a/drivers/iio/proximity/cros_ec_mkbp_proximity.c b/drivers/iio/proximity/cros_ec_mkbp_proximity.c
new file mode 100644
index 000000000000..8213b0081713
--- /dev/null
+++ b/drivers/iio/proximity/cros_ec_mkbp_proximity.c
@@ -0,0 +1,271 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Driver for cros-ec proximity sensor exposed through MKBP switch
+ *
+ * Copyright 2021 Google LLC.
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/mutex.h>
+#include <linux/notifier.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <linux/slab.h>
+#include <linux/types.h>
+
+#include <linux/platform_data/cros_ec_commands.h>
+#include <linux/platform_data/cros_ec_proto.h>
+
+#include <linux/iio/events.h>
+#include <linux/iio/iio.h>
+#include <linux/iio/sysfs.h>
+
+#include <asm/unaligned.h>
+
+struct cros_ec_mkbp_proximity_data {
+	struct cros_ec_device *ec;
+	struct iio_dev *indio_dev;
+	struct mutex lock;
+	struct notifier_block notifier;
+	int last_proximity;
+	bool enabled;
+};
+
+static const struct iio_event_spec cros_ec_mkbp_proximity_events[] = {
+	{
+		.type = IIO_EV_TYPE_THRESH,
+		.dir = IIO_EV_DIR_EITHER,
+		.mask_separate = BIT(IIO_EV_INFO_ENABLE),
+	},
+};
+
+static const struct iio_chan_spec cros_ec_mkbp_proximity_chan_spec[] = {
+	{
+		.type = IIO_PROXIMITY,
+		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
+		.event_spec = cros_ec_mkbp_proximity_events,
+		.num_event_specs = ARRAY_SIZE(cros_ec_mkbp_proximity_events),
+	},
+};
+
+static int cros_ec_mkbp_proximity_parse_state(const void *data)
+{
+	u32 switches = get_unaligned_le32(data);
+
+	return !!(switches & BIT(EC_MKBP_FRONT_PROXIMITY));
+}
+
+static int cros_ec_mkbp_proximity_query(struct cros_ec_device *ec_dev,
+					int *state)
+{
+	struct {
+		struct cros_ec_command msg;
+		union {
+			struct ec_params_mkbp_info params;
+			u32 switches;
+		};
+	} __packed buf = { };
+	struct ec_params_mkbp_info *params = &buf.params;
+	struct cros_ec_command *msg = &buf.msg;
+	u32 *switches = &buf.switches;
+	size_t insize = sizeof(*switches);
+	int ret;
+
+	msg->command = EC_CMD_MKBP_INFO;
+	msg->version = 1;
+	msg->outsize = sizeof(*params);
+	msg->insize = insize;
+
+	params->info_type = EC_MKBP_INFO_CURRENT;
+	params->event_type = EC_MKBP_EVENT_SWITCH;
+
+	ret = cros_ec_cmd_xfer_status(ec_dev, msg);
+	if (ret < 0)
+		return ret;
+
+	if (ret != insize) {
+		dev_warn(ec_dev->dev, "wrong result size: %d != %zu\n", ret,
+			 insize);
+		return -EPROTO;
+	}
+
+	*state = cros_ec_mkbp_proximity_parse_state(switches);
+	return IIO_VAL_INT;
+}
+
+static void cros_ec_mkbp_proximity_push_event(struct cros_ec_mkbp_proximity_data *data, int state)
+{
+	s64 timestamp;
+	u64 ev;
+	int dir;
+	struct iio_dev *indio_dev = data->indio_dev;
+	struct cros_ec_device *ec = data->ec;
+
+	mutex_lock(&data->lock);
+	if (state != data->last_proximity) {
+		if (data->enabled) {
+			timestamp = ktime_to_ns(ec->last_event_time);
+			if (iio_device_get_clock(indio_dev) != CLOCK_BOOTTIME)
+				timestamp = iio_get_time_ns(indio_dev);
+
+			dir = state ? IIO_EV_DIR_FALLING : IIO_EV_DIR_RISING;
+			ev = IIO_UNMOD_EVENT_CODE(IIO_PROXIMITY, 0,
+						  IIO_EV_TYPE_THRESH, dir);
+			iio_push_event(indio_dev, ev, timestamp);
+		}
+		data->last_proximity = state;
+	}
+	mutex_unlock(&data->lock);
+}
+
+static int cros_ec_mkbp_proximity_notify(struct notifier_block *nb,
+					 unsigned long queued_during_suspend,
+					 void *_ec)
+{
+	struct cros_ec_mkbp_proximity_data *data;
+	struct cros_ec_device *ec = _ec;
+	u8 event_type = ec->event_data.event_type & EC_MKBP_EVENT_TYPE_MASK;
+	void *switches;
+	int state;
+
+	if (event_type == EC_MKBP_EVENT_SWITCH) {
+		data = container_of(nb, struct cros_ec_mkbp_proximity_data,
+				    notifier);
+
+		switches = &ec->event_data.data.switches;
+		state = cros_ec_mkbp_proximity_parse_state(switches);
+		cros_ec_mkbp_proximity_push_event(data, state);
+	}
+
+	return NOTIFY_OK;
+}
+
+static int cros_ec_mkbp_proximity_read_raw(struct iio_dev *indio_dev,
+			   const struct iio_chan_spec *chan, int *val,
+			   int *val2, long mask)
+{
+	struct cros_ec_mkbp_proximity_data *data = iio_priv(indio_dev);
+	struct cros_ec_device *ec = data->ec;
+
+	if (chan->type == IIO_PROXIMITY && mask == IIO_CHAN_INFO_RAW)
+		return cros_ec_mkbp_proximity_query(ec, val);
+
+	return -EINVAL;
+}
+
+static int cros_ec_mkbp_proximity_read_event_config(struct iio_dev *indio_dev,
+				    const struct iio_chan_spec *chan,
+				    enum iio_event_type type,
+				    enum iio_event_direction dir)
+{
+	struct cros_ec_mkbp_proximity_data *data = iio_priv(indio_dev);
+
+	return data->enabled;
+}
+
+static int cros_ec_mkbp_proximity_write_event_config(struct iio_dev *indio_dev,
+				     const struct iio_chan_spec *chan,
+				     enum iio_event_type type,
+				     enum iio_event_direction dir, int state)
+{
+	struct cros_ec_mkbp_proximity_data *data = iio_priv(indio_dev);
+
+	mutex_lock(&data->lock);
+	data->enabled = state;
+	mutex_unlock(&data->lock);
+
+	return 0;
+}
+
+static const struct iio_info cros_ec_mkbp_proximity_info = {
+	.read_raw = cros_ec_mkbp_proximity_read_raw,
+	.read_event_config = cros_ec_mkbp_proximity_read_event_config,
+	.write_event_config = cros_ec_mkbp_proximity_write_event_config,
+};
+
+static __maybe_unused int cros_ec_mkbp_proximity_resume(struct device *dev)
+{
+	struct cros_ec_mkbp_proximity_data *data = dev_get_drvdata(dev);
+	struct cros_ec_device *ec = data->ec;
+	int ret, state;
+
+	ret = cros_ec_mkbp_proximity_query(ec, &state);
+	if (ret < 0) {
+		dev_warn(dev, "failed to fetch proximity state on resume: %d\n",
+			 ret);
+	} else {
+		cros_ec_mkbp_proximity_push_event(data, state);
+	}
+
+	return 0;
+}
+
+static SIMPLE_DEV_PM_OPS(cros_ec_mkbp_proximity_pm_ops, NULL,
+			 cros_ec_mkbp_proximity_resume);
+
+static int cros_ec_mkbp_proximity_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct cros_ec_device *ec = dev_get_drvdata(dev->parent);
+	struct iio_dev *indio_dev;
+	struct cros_ec_mkbp_proximity_data *data;
+	int ret;
+
+	indio_dev = devm_iio_device_alloc(dev, sizeof(*data));
+	if (!indio_dev)
+		return -ENOMEM;
+
+	data = iio_priv(indio_dev);
+	data->ec = ec;
+	data->indio_dev = indio_dev;
+	data->last_proximity = -1; /* Unknown to start */
+	mutex_init(&data->lock);
+	platform_set_drvdata(pdev, data);
+
+	indio_dev->name = dev->driver->name;
+	indio_dev->info = &cros_ec_mkbp_proximity_info;
+	indio_dev->modes = INDIO_DIRECT_MODE;
+	indio_dev->channels = cros_ec_mkbp_proximity_chan_spec;
+	indio_dev->num_channels = ARRAY_SIZE(cros_ec_mkbp_proximity_chan_spec);
+
+	ret = devm_iio_device_register(dev, indio_dev);
+	if (ret)
+		return ret;
+
+	data->notifier.notifier_call = cros_ec_mkbp_proximity_notify;
+	blocking_notifier_chain_register(&ec->event_notifier, &data->notifier);
+
+	return 0;
+}
+
+static int cros_ec_mkbp_proximity_remove(struct platform_device *pdev)
+{
+	struct cros_ec_mkbp_proximity_data *data = platform_get_drvdata(pdev);
+	struct cros_ec_device *ec = data->ec;
+
+	blocking_notifier_chain_unregister(&ec->event_notifier,
+					   &data->notifier);
+
+	return 0;
+}
+
+static const struct of_device_id cros_ec_mkbp_proximity_of_match[] = {
+	{ .compatible = "google,cros-ec-mkbp-proximity" },
+	{}
+};
+MODULE_DEVICE_TABLE(of, cros_ec_mkbp_proximity_of_match);
+
+static struct platform_driver cros_ec_mkbp_proximity_driver = {
+	.driver = {
+		.name = "cros-ec-mkbp-proximity",
+		.of_match_table = cros_ec_mkbp_proximity_of_match,
+		.pm = &cros_ec_mkbp_proximity_pm_ops,
+	},
+	.probe = cros_ec_mkbp_proximity_probe,
+	.remove = cros_ec_mkbp_proximity_remove,
+};
+module_platform_driver(cros_ec_mkbp_proximity_driver);
+
+MODULE_LICENSE("GPL v2");
+MODULE_DESCRIPTION("ChromeOS EC MKBP proximity sensor driver");
-- 
https://chromeos.dev

Re: [PATCH v6 3/3] iio: proximity: Add a ChromeOS EC MKBP proximity driver

[Jonathan Cameron]

On Wed, 10 Feb 2021 18:46:01 -0800
Stephen Boyd <swboyd@chromium.org> wrote:

> Add support for a ChromeOS EC proximity driver that exposes a "front"
> proximity sensor via the IIO subsystem. The EC decides when front
> proximity is near and sets an MKBP switch 'EC_MKBP_FRONT_PROXIMITY' to
> notify the kernel of proximity. Similarly, when proximity detects
> something far away it sets the switch bit to 0. For now this driver
> exposes a single sensor, but it could be expanded in the future via more
> MKBP bits if desired.
> 
> 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 <gwendal@chromium.org>
> Reviewed-by: Enric Balletbo i Serra <enric.balletbo@collabora.com>
> Signed-off-by: Stephen Boyd <swboyd@chromium.org>

I'm fine with this, but want to leave a little time for others to take
one last look.  We've missed the coming merge window now anyway.

If I seem to have forgotten this in a couple of weeks, feel free to
give me a bump.

Thanks,

Jonathan
> ---
> 
> Changes from v5:
>  * Only push event if it's different
>  * Check switch on resume
> 
>  drivers/iio/proximity/Kconfig                 |  11 +
>  drivers/iio/proximity/Makefile                |   1 +
>  .../iio/proximity/cros_ec_mkbp_proximity.c    | 271 ++++++++++++++++++
>  3 files changed, 283 insertions(+)
>  create mode 100644 drivers/iio/proximity/cros_ec_mkbp_proximity.c
> 
> diff --git a/drivers/iio/proximity/Kconfig b/drivers/iio/proximity/Kconfig
> index 12672a0e89ed..7c7203ca3ac6 100644
> --- a/drivers/iio/proximity/Kconfig
> +++ b/drivers/iio/proximity/Kconfig
> @@ -21,6 +21,17 @@ endmenu
>  
>  menu "Proximity and distance sensors"
>  
> +config CROS_EC_MKBP_PROXIMITY
> +	tristate "ChromeOS EC MKBP Proximity sensor"
> +	depends on CROS_EC
> +	help
> +	  Say Y here to enable the proximity sensor implemented via the ChromeOS EC MKBP
> +	  switches protocol. You must enable one bus option (CROS_EC_I2C or CROS_EC_SPI)
> +	  to use this.
> +
> +	  To compile this driver as a module, choose M here: the
> +	  module will be called cros_ec_mkbp_proximity.
> +
>  config ISL29501
>  	tristate "Intersil ISL29501 Time Of Flight sensor"
>  	depends on I2C
> diff --git a/drivers/iio/proximity/Makefile b/drivers/iio/proximity/Makefile
> index 9c1aca1a8b79..cbdac09433eb 100644
> --- a/drivers/iio/proximity/Makefile
> +++ b/drivers/iio/proximity/Makefile
> @@ -5,6 +5,7 @@
>  
>  # When adding new entries keep the list in alphabetical order
>  obj-$(CONFIG_AS3935)		+= as3935.o
> +obj-$(CONFIG_CROS_EC_MKBP_PROXIMITY) += cros_ec_mkbp_proximity.o
>  obj-$(CONFIG_ISL29501)		+= isl29501.o
>  obj-$(CONFIG_LIDAR_LITE_V2)	+= pulsedlight-lidar-lite-v2.o
>  obj-$(CONFIG_MB1232)		+= mb1232.o
> diff --git a/drivers/iio/proximity/cros_ec_mkbp_proximity.c b/drivers/iio/proximity/cros_ec_mkbp_proximity.c
> new file mode 100644
> index 000000000000..8213b0081713
> --- /dev/null
> +++ b/drivers/iio/proximity/cros_ec_mkbp_proximity.c
> @@ -0,0 +1,271 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * Driver for cros-ec proximity sensor exposed through MKBP switch
> + *
> + * Copyright 2021 Google LLC.
> + */
> +
> +#include <linux/kernel.h>
> +#include <linux/module.h>
> +#include <linux/mutex.h>
> +#include <linux/notifier.h>
> +#include <linux/of.h>
> +#include <linux/platform_device.h>
> +#include <linux/slab.h>
> +#include <linux/types.h>
> +
> +#include <linux/platform_data/cros_ec_commands.h>
> +#include <linux/platform_data/cros_ec_proto.h>
> +
> +#include <linux/iio/events.h>
> +#include <linux/iio/iio.h>
> +#include <linux/iio/sysfs.h>
> +
> +#include <asm/unaligned.h>
> +
> +struct cros_ec_mkbp_proximity_data {
> +	struct cros_ec_device *ec;
> +	struct iio_dev *indio_dev;
> +	struct mutex lock;
> +	struct notifier_block notifier;
> +	int last_proximity;
> +	bool enabled;
> +};
> +
> +static const struct iio_event_spec cros_ec_mkbp_proximity_events[] = {
> +	{
> +		.type = IIO_EV_TYPE_THRESH,
> +		.dir = IIO_EV_DIR_EITHER,
> +		.mask_separate = BIT(IIO_EV_INFO_ENABLE),
> +	},
> +};
> +
> +static const struct iio_chan_spec cros_ec_mkbp_proximity_chan_spec[] = {
> +	{
> +		.type = IIO_PROXIMITY,
> +		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
> +		.event_spec = cros_ec_mkbp_proximity_events,
> +		.num_event_specs = ARRAY_SIZE(cros_ec_mkbp_proximity_events),
> +	},
> +};
> +
> +static int cros_ec_mkbp_proximity_parse_state(const void *data)
> +{
> +	u32 switches = get_unaligned_le32(data);
> +
> +	return !!(switches & BIT(EC_MKBP_FRONT_PROXIMITY));
> +}
> +
> +static int cros_ec_mkbp_proximity_query(struct cros_ec_device *ec_dev,
> +					int *state)
> +{
> +	struct {
> +		struct cros_ec_command msg;
> +		union {
> +			struct ec_params_mkbp_info params;
> +			u32 switches;
> +		};
> +	} __packed buf = { };
> +	struct ec_params_mkbp_info *params = &buf.params;
> +	struct cros_ec_command *msg = &buf.msg;
> +	u32 *switches = &buf.switches;
> +	size_t insize = sizeof(*switches);
> +	int ret;
> +
> +	msg->command = EC_CMD_MKBP_INFO;
> +	msg->version = 1;
> +	msg->outsize = sizeof(*params);
> +	msg->insize = insize;
> +
> +	params->info_type = EC_MKBP_INFO_CURRENT;
> +	params->event_type = EC_MKBP_EVENT_SWITCH;
> +
> +	ret = cros_ec_cmd_xfer_status(ec_dev, msg);
> +	if (ret < 0)
> +		return ret;
> +
> +	if (ret != insize) {
> +		dev_warn(ec_dev->dev, "wrong result size: %d != %zu\n", ret,
> +			 insize);
> +		return -EPROTO;
> +	}
> +
> +	*state = cros_ec_mkbp_proximity_parse_state(switches);
> +	return IIO_VAL_INT;
> +}
> +
> +static void cros_ec_mkbp_proximity_push_event(struct cros_ec_mkbp_proximity_data *data, int state)
> +{
> +	s64 timestamp;
> +	u64 ev;
> +	int dir;
> +	struct iio_dev *indio_dev = data->indio_dev;
> +	struct cros_ec_device *ec = data->ec;
> +
> +	mutex_lock(&data->lock);
> +	if (state != data->last_proximity) {
> +		if (data->enabled) {
> +			timestamp = ktime_to_ns(ec->last_event_time);
> +			if (iio_device_get_clock(indio_dev) != CLOCK_BOOTTIME)
> +				timestamp = iio_get_time_ns(indio_dev);
> +
> +			dir = state ? IIO_EV_DIR_FALLING : IIO_EV_DIR_RISING;
> +			ev = IIO_UNMOD_EVENT_CODE(IIO_PROXIMITY, 0,
> +						  IIO_EV_TYPE_THRESH, dir);
> +			iio_push_event(indio_dev, ev, timestamp);
> +		}
> +		data->last_proximity = state;
> +	}
> +	mutex_unlock(&data->lock);
> +}
> +
> +static int cros_ec_mkbp_proximity_notify(struct notifier_block *nb,
> +					 unsigned long queued_during_suspend,
> +					 void *_ec)
> +{
> +	struct cros_ec_mkbp_proximity_data *data;
> +	struct cros_ec_device *ec = _ec;
> +	u8 event_type = ec->event_data.event_type & EC_MKBP_EVENT_TYPE_MASK;
> +	void *switches;
> +	int state;
> +
> +	if (event_type == EC_MKBP_EVENT_SWITCH) {
> +		data = container_of(nb, struct cros_ec_mkbp_proximity_data,
> +				    notifier);
> +
> +		switches = &ec->event_data.data.switches;
> +		state = cros_ec_mkbp_proximity_parse_state(switches);
> +		cros_ec_mkbp_proximity_push_event(data, state);
> +	}
> +
> +	return NOTIFY_OK;
> +}
> +
> +static int cros_ec_mkbp_proximity_read_raw(struct iio_dev *indio_dev,
> +			   const struct iio_chan_spec *chan, int *val,
> +			   int *val2, long mask)
> +{
> +	struct cros_ec_mkbp_proximity_data *data = iio_priv(indio_dev);
> +	struct cros_ec_device *ec = data->ec;
> +
> +	if (chan->type == IIO_PROXIMITY && mask == IIO_CHAN_INFO_RAW)
> +		return cros_ec_mkbp_proximity_query(ec, val);
> +
> +	return -EINVAL;
> +}
> +
> +static int cros_ec_mkbp_proximity_read_event_config(struct iio_dev *indio_dev,
> +				    const struct iio_chan_spec *chan,
> +				    enum iio_event_type type,
> +				    enum iio_event_direction dir)
> +{
> +	struct cros_ec_mkbp_proximity_data *data = iio_priv(indio_dev);
> +
> +	return data->enabled;
> +}
> +
> +static int cros_ec_mkbp_proximity_write_event_config(struct iio_dev *indio_dev,
> +				     const struct iio_chan_spec *chan,
> +				     enum iio_event_type type,
> +				     enum iio_event_direction dir, int state)
> +{
> +	struct cros_ec_mkbp_proximity_data *data = iio_priv(indio_dev);
> +
> +	mutex_lock(&data->lock);
> +	data->enabled = state;
> +	mutex_unlock(&data->lock);
> +
> +	return 0;
> +}
> +
> +static const struct iio_info cros_ec_mkbp_proximity_info = {
> +	.read_raw = cros_ec_mkbp_proximity_read_raw,
> +	.read_event_config = cros_ec_mkbp_proximity_read_event_config,
> +	.write_event_config = cros_ec_mkbp_proximity_write_event_config,
> +};
> +
> +static __maybe_unused int cros_ec_mkbp_proximity_resume(struct device *dev)
> +{
> +	struct cros_ec_mkbp_proximity_data *data = dev_get_drvdata(dev);
> +	struct cros_ec_device *ec = data->ec;
> +	int ret, state;
> +
> +	ret = cros_ec_mkbp_proximity_query(ec, &state);
> +	if (ret < 0) {
> +		dev_warn(dev, "failed to fetch proximity state on resume: %d\n",
> +			 ret);
> +	} else {
> +		cros_ec_mkbp_proximity_push_event(data, state);
> +	}
> +
> +	return 0;
> +}
> +
> +static SIMPLE_DEV_PM_OPS(cros_ec_mkbp_proximity_pm_ops, NULL,
> +			 cros_ec_mkbp_proximity_resume);
> +
> +static int cros_ec_mkbp_proximity_probe(struct platform_device *pdev)
> +{
> +	struct device *dev = &pdev->dev;
> +	struct cros_ec_device *ec = dev_get_drvdata(dev->parent);
> +	struct iio_dev *indio_dev;
> +	struct cros_ec_mkbp_proximity_data *data;
> +	int ret;
> +
> +	indio_dev = devm_iio_device_alloc(dev, sizeof(*data));
> +	if (!indio_dev)
> +		return -ENOMEM;
> +
> +	data = iio_priv(indio_dev);
> +	data->ec = ec;
> +	data->indio_dev = indio_dev;
> +	data->last_proximity = -1; /* Unknown to start */
> +	mutex_init(&data->lock);
> +	platform_set_drvdata(pdev, data);
> +
> +	indio_dev->name = dev->driver->name;
> +	indio_dev->info = &cros_ec_mkbp_proximity_info;
> +	indio_dev->modes = INDIO_DIRECT_MODE;
> +	indio_dev->channels = cros_ec_mkbp_proximity_chan_spec;
> +	indio_dev->num_channels = ARRAY_SIZE(cros_ec_mkbp_proximity_chan_spec);
> +
> +	ret = devm_iio_device_register(dev, indio_dev);
> +	if (ret)
> +		return ret;
> +
> +	data->notifier.notifier_call = cros_ec_mkbp_proximity_notify;
> +	blocking_notifier_chain_register(&ec->event_notifier, &data->notifier);
> +
> +	return 0;
> +}
> +
> +static int cros_ec_mkbp_proximity_remove(struct platform_device *pdev)
> +{
> +	struct cros_ec_mkbp_proximity_data *data = platform_get_drvdata(pdev);
> +	struct cros_ec_device *ec = data->ec;
> +
> +	blocking_notifier_chain_unregister(&ec->event_notifier,
> +					   &data->notifier);
> +
> +	return 0;
> +}
> +
> +static const struct of_device_id cros_ec_mkbp_proximity_of_match[] = {
> +	{ .compatible = "google,cros-ec-mkbp-proximity" },
> +	{}
> +};
> +MODULE_DEVICE_TABLE(of, cros_ec_mkbp_proximity_of_match);
> +
> +static struct platform_driver cros_ec_mkbp_proximity_driver = {
> +	.driver = {
> +		.name = "cros-ec-mkbp-proximity",
> +		.of_match_table = cros_ec_mkbp_proximity_of_match,
> +		.pm = &cros_ec_mkbp_proximity_pm_ops,
> +	},
> +	.probe = cros_ec_mkbp_proximity_probe,
> +	.remove = cros_ec_mkbp_proximity_remove,
> +};
> +module_platform_driver(cros_ec_mkbp_proximity_driver);
> +
> +MODULE_LICENSE("GPL v2");
> +MODULE_DESCRIPTION("ChromeOS EC MKBP proximity sensor driver");

Re: [PATCH v6 3/3] iio: proximity: Add a ChromeOS EC MKBP proximity driver

[Stephen Boyd]

Quoting Jonathan Cameron (2021-02-14 04:48:09)
> On Wed, 10 Feb 2021 18:46:01 -0800
> Stephen Boyd <swboyd@chromium.org> wrote:
> 
> > Add support for a ChromeOS EC proximity driver that exposes a "front"
> > proximity sensor via the IIO subsystem. The EC decides when front
> > proximity is near and sets an MKBP switch 'EC_MKBP_FRONT_PROXIMITY' to
> > notify the kernel of proximity. Similarly, when proximity detects
> > something far away it sets the switch bit to 0. For now this driver
> > exposes a single sensor, but it could be expanded in the future via more
> > MKBP bits if desired.
> > 
> > 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 <gwendal@chromium.org>
> > Reviewed-by: Enric Balletbo i Serra <enric.balletbo@collabora.com>
> > Signed-off-by: Stephen Boyd <swboyd@chromium.org>
> 
> I'm fine with this, but want to leave a little time for others to take
> one last look.  We've missed the coming merge window now anyway.
> 
> If I seem to have forgotten this in a couple of weeks, feel free to
> give me a bump.
> 

Ok no problem. Gwendal had some comments on v5 that may be applicable
here too but I think they mostly mean that the resume handler may not be
needed if cros ec is fixed. Having the resume handler shouldn't hurt
though unless I missed something. Gwendal?

Re: [PATCH v6 3/3] iio: proximity: Add a ChromeOS EC MKBP proximity driver

[Jonathan Cameron]

On Sun, 14 Feb 2021 12:39:58 -0800
Stephen Boyd <swboyd@chromium.org> wrote:

> Quoting Jonathan Cameron (2021-02-14 04:48:09)
> > On Wed, 10 Feb 2021 18:46:01 -0800
> > Stephen Boyd <swboyd@chromium.org> wrote:
> >   
> > > Add support for a ChromeOS EC proximity driver that exposes a "front"
> > > proximity sensor via the IIO subsystem. The EC decides when front
> > > proximity is near and sets an MKBP switch 'EC_MKBP_FRONT_PROXIMITY' to
> > > notify the kernel of proximity. Similarly, when proximity detects
> > > something far away it sets the switch bit to 0. For now this driver
> > > exposes a single sensor, but it could be expanded in the future via more
> > > MKBP bits if desired.
> > > 
> > > 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 <gwendal@chromium.org>
> > > Reviewed-by: Enric Balletbo i Serra <enric.balletbo@collabora.com>
> > > Signed-off-by: Stephen Boyd <swboyd@chromium.org>  
> > 
> > I'm fine with this, but want to leave a little time for others to take
> > one last look.  We've missed the coming merge window now anyway.
> > 
> > If I seem to have forgotten this in a couple of weeks, feel free to
> > give me a bump.
> >   
> 
> Ok no problem. Gwendal had some comments on v5 that may be applicable
> here too but I think they mostly mean that the resume handler may not be
> needed if cros ec is fixed. Having the resume handler shouldn't hurt
> though unless I missed something. Gwendal?

@Gwendal, could you take a quick glance at this, or alternatively let
us know if you need more time to get to it.

Thanks,

Jonathan

Re: [PATCH v6 3/3] iio: proximity: Add a ChromeOS EC MKBP proximity driver

[Gwendal Grignou]

On Sun, Feb 21, 2021 at 7:53 AM Jonathan Cameron <jic23@kernel.org> wrote:
>
> On Sun, 14 Feb 2021 12:39:58 -0800
> Stephen Boyd <swboyd@chromium.org> wrote:
>
> > Quoting Jonathan Cameron (2021-02-14 04:48:09)
> > > On Wed, 10 Feb 2021 18:46:01 -0800
> > > Stephen Boyd <swboyd@chromium.org> wrote:
> > >
> > > > Add support for a ChromeOS EC proximity driver that exposes a "front"
> > > > proximity sensor via the IIO subsystem. The EC decides when front
> > > > proximity is near and sets an MKBP switch 'EC_MKBP_FRONT_PROXIMITY' to
> > > > notify the kernel of proximity. Similarly, when proximity detects
> > > > something far away it sets the switch bit to 0. For now this driver
> > > > exposes a single sensor, but it could be expanded in the future via more
> > > > MKBP bits if desired.
> > > >
> > > > 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 <gwendal@chromium.org>
> > > > Reviewed-by: Enric Balletbo i Serra <enric.balletbo@collabora.com>
> > > > Signed-off-by: Stephen Boyd <swboyd@chromium.org>
> > >
> > > I'm fine with this, but want to leave a little time for others to take
> > > one last look.  We've missed the coming merge window now anyway.
> > >
> > > If I seem to have forgotten this in a couple of weeks, feel free to
> > > give me a bump.
> > >
> >
> > Ok no problem. Gwendal had some comments on v5 that may be applicable
> > here too but I think they mostly mean that the resume handler may not be
> > needed if cros ec is fixed. Having the resume handler shouldn't hurt
> > though unless I missed something. Gwendal?
>
> @Gwendal, could you take a quick glance at this, or alternatively let
> us know if you need more time to get to it.
It will work as is.

Reviewed-by: Gwendal Grignou <gwendal@chromium.org>
>
> Thanks,
>
> Jonathan
>
>

Re: [PATCH v6 3/3] iio: proximity: Add a ChromeOS EC MKBP proximity driver

[Jonathan Cameron]

On Fri, 12 Mar 2021 13:23:35 -0800
Gwendal Grignou <gwendal@chromium.org> wrote:

> On Sun, Feb 21, 2021 at 7:53 AM Jonathan Cameron <jic23@kernel.org> wrote:
> >
> > On Sun, 14 Feb 2021 12:39:58 -0800
> > Stephen Boyd <swboyd@chromium.org> wrote:
> >  
> > > Quoting Jonathan Cameron (2021-02-14 04:48:09)  
> > > > On Wed, 10 Feb 2021 18:46:01 -0800
> > > > Stephen Boyd <swboyd@chromium.org> wrote:
> > > >  
> > > > > Add support for a ChromeOS EC proximity driver that exposes a "front"
> > > > > proximity sensor via the IIO subsystem. The EC decides when front
> > > > > proximity is near and sets an MKBP switch 'EC_MKBP_FRONT_PROXIMITY' to
> > > > > notify the kernel of proximity. Similarly, when proximity detects
> > > > > something far away it sets the switch bit to 0. For now this driver
> > > > > exposes a single sensor, but it could be expanded in the future via more
> > > > > MKBP bits if desired.
> > > > >
> > > > > 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 <gwendal@chromium.org>
> > > > > Reviewed-by: Enric Balletbo i Serra <enric.balletbo@collabora.com>
> > > > > Signed-off-by: Stephen Boyd <swboyd@chromium.org>  
> > > >
> > > > I'm fine with this, but want to leave a little time for others to take
> > > > one last look.  We've missed the coming merge window now anyway.
> > > >
> > > > If I seem to have forgotten this in a couple of weeks, feel free to
> > > > give me a bump.
> > > >  
> > >
> > > Ok no problem. Gwendal had some comments on v5 that may be applicable
> > > here too but I think they mostly mean that the resume handler may not be
> > > needed if cros ec is fixed. Having the resume handler shouldn't hurt
> > > though unless I missed something. Gwendal?  
> >
> > @Gwendal, could you take a quick glance at this, or alternatively let
> > us know if you need more time to get to it.  
> It will work as is.
> 
> Reviewed-by: Gwendal Grignou <gwendal@chromium.org>
Applied to the togreg branch of iio.git.  My local build test highlighted
a much older kernel-doc naming issue so I've sent out a patch to tidy that
up whilst we are here.

Thanks,

Jonathan

> >
> > Thanks,
> >
> > Jonathan
> >
> >