[PATCH v4 0/3] add custom hinge sensor support

[PATCH v4 0/3] add custom hinge sensor support

[Ye Xiang]

Here we register one iio device with three channels which present angle for
hinge, keyboard and screen.

This driver works on devices with Intel integrated sensor hub, where
hinge sensor is presented using a custom sensor usage id.

Here the angle is presented in degrees, which is converted to radians.

Changes since v3:
  - hid-sensor-custom: remove sensor_inst::custom_pdev_exposed.
  - hid-sensor-custom: use static buf, w_buf to avoid using goto in 
    get_known_custom_sensor_index.
  - hid-sensor-custom-intel-hinge: use devm_ prefix function instead.
  - sysfs-bus-iio: put in_anglY_raw together with in_angl_raw.

Changes since v2:
  - use 1 iio device instead of 3 for hinge sensor.
  - use indexed channel instead of modified channel and added channel
    labels.
  - remove 2,3 patch in last version, add a document patch to describe the
    hinge channels.
  - hid-sensor-custom: use meaningful return value in 
    get_known_custom_sensor_index and checked in call side.
  - hid-sensor-ids.h: use HID_USAGE_SENSOR_DATA_FIELD_CUSTOM_VALUE(x) to 
    define custom sensor value.

Changes since v1:
  - fixed errors reported by lkp

Ye Xiang (3):
  HID: hid-sensor-custom: Add custom sensor iio support
  iio: hid-sensors: Add hinge sensor driver
  iio:Documentation: Add documentation for hinge sensor channels

 Documentation/ABI/testing/sysfs-bus-iio       |  11 +
 drivers/hid/hid-sensor-custom.c               | 143 +++++++
 .../hid-sensors/hid-sensor-attributes.c       |   2 +
 drivers/iio/position/Kconfig                  |  16 +
 drivers/iio/position/Makefile                 |   1 +
 .../position/hid-sensor-custom-intel-hinge.c  | 391 ++++++++++++++++++
 include/linux/hid-sensor-ids.h                |  14 +
 7 files changed, 578 insertions(+)
 create mode 100644 drivers/iio/position/hid-sensor-custom-intel-hinge.c

-- 
2.17.1

[PATCH v4 1/3] HID: hid-sensor-custom: Add custom sensor iio support

[Ye Xiang]

Currently custom sensors properties are not decoded and it is up to
user space to interpret.

Some manufacturers already standardized the meaning of some custom sensors.
They can be presented as a proper IIO sensor. We can identify these sensors
based on manufacturer and serial number property in the report.

This change is identifying hinge sensor when the manufacturer is "INTEL".
This creates a platform device so that a sensor driver can be loaded to
process these sensors.

Signed-off-by: Ye Xiang <xiang.ye@intel.com>
---
 drivers/hid/hid-sensor-custom.c | 143 ++++++++++++++++++++++++++++++++
 include/linux/hid-sensor-ids.h  |  14 ++++
 2 files changed, 157 insertions(+)

diff --git a/drivers/hid/hid-sensor-custom.c b/drivers/hid/hid-sensor-custom.c
index 4d25577a8573..2628bc53ed80 100644
--- a/drivers/hid/hid-sensor-custom.c
+++ b/drivers/hid/hid-sensor-custom.c
@@ -4,6 +4,7 @@
  * Copyright (c) 2015, Intel Corporation.
  */
 
+#include <linux/ctype.h>
 #include <linux/kernel.h>
 #include <linux/module.h>
 #include <linux/init.h>
@@ -21,6 +22,7 @@
 #define HID_CUSTOM_TOTAL_ATTRS		(HID_CUSTOM_MAX_CORE_ATTRS + 1)
 #define HID_CUSTOM_FIFO_SIZE		4096
 #define HID_CUSTOM_MAX_FEATURE_BYTES	64
+#define HID_SENSOR_USAGE_LENGTH (4 + 1)
 
 struct hid_sensor_custom_field {
 	int report_id;
@@ -50,6 +52,7 @@ struct hid_sensor_custom {
 	struct kfifo data_fifo;
 	unsigned long misc_opened;
 	wait_queue_head_t wait;
+	struct platform_device *custom_pdev;
 };
 
 /* Header for each sample to user space via dev interface */
@@ -746,11 +749,130 @@ static void hid_sensor_custom_dev_if_remove(struct hid_sensor_custom
 
 }
 
+/* luid defined in FW (e.g. ISH).  Maybe used to identify sensor. */
+static const char *const known_sensor_luid[] = { "020B000000000000" };
+
+static int get_luid_table_index(unsigned char *usage_str)
+{
+	int i;
+
+	for (i = 0; i < ARRAY_SIZE(known_sensor_luid); i++) {
+		if (!strncmp(usage_str, known_sensor_luid[i],
+			     strlen(known_sensor_luid[i])))
+			return i;
+	}
+
+	return -ENODEV;
+}
+
+static int get_known_custom_sensor_index(struct hid_sensor_hub_device *hsdev)
+{
+	struct hid_sensor_hub_attribute_info sensor_manufacturer = { 0 };
+	struct hid_sensor_hub_attribute_info sensor_luid_info = { 0 };
+	int report_size;
+	int ret;
+	static u16 w_buf[HID_CUSTOM_MAX_FEATURE_BYTES];
+	static char buf[HID_CUSTOM_MAX_FEATURE_BYTES];
+	int i;
+
+	memset(w_buf, 0, sizeof(w_buf));
+	memset(buf, 0, sizeof(buf));
+
+	/* get manufacturer info */
+	ret = sensor_hub_input_get_attribute_info(hsdev,
+			HID_FEATURE_REPORT, hsdev->usage,
+			HID_USAGE_SENSOR_PROP_MANUFACTURER, &sensor_manufacturer);
+	if (ret < 0)
+		return ret;
+
+	report_size =
+		sensor_hub_get_feature(hsdev, sensor_manufacturer.report_id,
+				       sensor_manufacturer.index, sizeof(w_buf),
+				       w_buf);
+	if (report_size <= 0) {
+		hid_err(hsdev->hdev,
+			"Failed to get sensor manufacturer info %d\n",
+			report_size);
+		return -ENODEV;
+	}
+
+	/* convert from wide char to char */
+	for (i = 0; i < ARRAY_SIZE(buf) - 1 && w_buf[i]; i++)
+		buf[i] = (char)w_buf[i];
+
+	/* ensure it's ISH sensor */
+	if (strncmp(buf, "INTEL", strlen("INTEL")))
+		return -ENODEV;
+
+	memset(w_buf, 0, sizeof(w_buf));
+	memset(buf, 0, sizeof(buf));
+
+	/* get real usage id */
+	ret = sensor_hub_input_get_attribute_info(hsdev,
+			HID_FEATURE_REPORT, hsdev->usage,
+			HID_USAGE_SENSOR_PROP_SERIAL_NUM, &sensor_luid_info);
+	if (ret < 0)
+		return ret;
+
+	report_size = sensor_hub_get_feature(hsdev, sensor_luid_info.report_id,
+					     sensor_luid_info.index, sizeof(w_buf),
+					     w_buf);
+	if (report_size <= 0) {
+		hid_err(hsdev->hdev, "Failed to get real usage info %d\n",
+			report_size);
+		return -ENODEV;
+	}
+
+	/* convert from wide char to char */
+	for (i = 0; i < ARRAY_SIZE(buf) - 1 && w_buf[i]; i++)
+		buf[i] = (char)w_buf[i];
+
+	if (strlen(buf) != strlen(known_sensor_luid[0]) + 5) {
+		hid_err(hsdev->hdev,
+			"%s luid length not match %zu != (%zu + 5)\n", __func__,
+			strlen(buf), strlen(known_sensor_luid[0]));
+		return -ENODEV;
+	}
+
+	/* get table index with luid (not matching 'LUID: ' in luid) */
+	return get_luid_table_index(&buf[5]);
+}
+
+static struct platform_device *
+hid_sensor_register_platform_device(struct platform_device *pdev,
+				    struct hid_sensor_hub_device *hsdev,
+				    int index)
+{
+	char real_usage[HID_SENSOR_USAGE_LENGTH] = { 0 };
+	struct platform_device *custom_pdev;
+	const char *dev_name;
+	char *c;
+
+	/* copy real usage id */
+	memcpy(real_usage, known_sensor_luid[index], 4);
+
+	/* usage id are all lowcase */
+	for (c = real_usage; *c != '\0'; c++)
+		*c = tolower(*c);
+
+	/* HID-SENSOR-INT-REAL_USAGE_ID */
+	dev_name = kasprintf(GFP_KERNEL, "HID-SENSOR-INT-%s", real_usage);
+	if (!dev_name)
+		return ERR_PTR(-ENOMEM);
+
+	custom_pdev = platform_device_register_data(pdev->dev.parent, dev_name,
+						    PLATFORM_DEVID_NONE, hsdev,
+						    sizeof(*hsdev));
+	kfree(dev_name);
+	return custom_pdev;
+}
+
 static int hid_sensor_custom_probe(struct platform_device *pdev)
 {
 	struct hid_sensor_custom *sensor_inst;
 	struct hid_sensor_hub_device *hsdev = pdev->dev.platform_data;
 	int ret;
+	int index;
 
 	sensor_inst = devm_kzalloc(&pdev->dev, sizeof(*sensor_inst),
 				   GFP_KERNEL);
@@ -764,6 +886,22 @@ static int hid_sensor_custom_probe(struct platform_device *pdev)
 	sensor_inst->pdev = pdev;
 	mutex_init(&sensor_inst->mutex);
 	platform_set_drvdata(pdev, sensor_inst);
+
+	index = get_known_custom_sensor_index(hsdev);
+	if (index >= 0 && index < ARRAY_SIZE(known_sensor_luid)) {
+		sensor_inst->custom_pdev =
+			hid_sensor_register_platform_device(pdev, hsdev, index);
+
+		ret = PTR_ERR_OR_ZERO(sensor_inst->custom_pdev);
+		if (ret) {
+			dev_err(&pdev->dev,
+				"register_platform_device failed\n");
+			return ret;
+		}
+
+		return 0;
+	}
+
 	ret = sensor_hub_register_callback(hsdev, hsdev->usage,
 					   &sensor_inst->callbacks);
 	if (ret < 0) {
@@ -802,6 +940,11 @@ static int hid_sensor_custom_remove(struct platform_device *pdev)
 	struct hid_sensor_custom *sensor_inst = platform_get_drvdata(pdev);
 	struct hid_sensor_hub_device *hsdev = pdev->dev.platform_data;
 
+	if (sensor_inst->custom_pdev) {
+		platform_device_unregister(sensor_inst->custom_pdev);
+		return 0;
+	}
+
 	hid_sensor_custom_dev_if_remove(sensor_inst);
 	hid_sensor_custom_remove_attributes(sensor_inst);
 	sysfs_remove_group(&sensor_inst->pdev->dev.kobj,
diff --git a/include/linux/hid-sensor-ids.h b/include/linux/hid-sensor-ids.h
index 530c09f3e64a..ac631159403a 100644
--- a/include/linux/hid-sensor-ids.h
+++ b/include/linux/hid-sensor-ids.h
@@ -128,6 +128,10 @@
 #define HID_USAGE_SENSOR_UNITS_DEGREES_PER_SECOND		0x15
 
 /* Common selectors */
+#define HID_USAGE_SENSOR_PROP_DESC				0x200300
+#define HID_USAGE_SENSOR_PROP_FRIENDLY_NAME			0x200301
+#define HID_USAGE_SENSOR_PROP_SERIAL_NUM			0x200307
+#define HID_USAGE_SENSOR_PROP_MANUFACTURER			0x200305
 #define HID_USAGE_SENSOR_PROP_REPORT_INTERVAL			0x20030E
 #define HID_USAGE_SENSOR_PROP_SENSITIVITY_ABS			0x20030F
 #define HID_USAGE_SENSOR_PROP_SENSITIVITY_RANGE_PCT		0x200310
@@ -159,4 +163,14 @@
 #define HID_USAGE_SENSOR_PROP_REPORTING_STATE_NO_EVENTS_ENUM	0x200840
 #define HID_USAGE_SENSOR_PROP_REPORTING_STATE_ALL_EVENTS_ENUM	0x200841
 
+/* Custom Sensor (2000e1) */
+#define HID_USAGE_SENSOR_HINGE				        0x20020B
+#define HID_USAGE_SENSOR_DATA_FIELD_LOCATION			0x200400
+#define HID_USAGE_SENSOR_DATA_FIELE_TIME_SINCE_SYS_BOOT		0x20052B
+#define HID_USAGE_SENSOR_DATA_FIELD_CUSTOM_USAGE		0x200541
+#define HID_USAGE_SENSOR_DATA_FIELD_CUSTOM_VALUE_BASE           0x200543
+/* Custom Sensor data 28=>x>=0 */
+#define HID_USAGE_SENSOR_DATA_FIELD_CUSTOM_VALUE(x)                            \
+	(HID_USAGE_SENSOR_DATA_FIELD_CUSTOM_VALUE_BASE + (x))
+
 #endif
-- 
2.17.1

[PATCH v4 2/3] iio: hid-sensors: Add hinge sensor driver

[Ye Xiang]

The Hinge sensor is a common custom sensor on laptops. It calculates
the angle between the lid (screen) and the base (keyboard). In addition,
it also exposes screen and the keyboard angles with respect to the
ground. Applications can easily get laptop's status in space through
this sensor, in order to display appropriate user interface.

Signed-off-by: Ye Xiang <xiang.ye@intel.com>
---
 .../hid-sensors/hid-sensor-attributes.c       |   2 +
 drivers/iio/position/Kconfig                  |  16 +
 drivers/iio/position/Makefile                 |   1 +
 .../position/hid-sensor-custom-intel-hinge.c  | 391 ++++++++++++++++++
 4 files changed, 410 insertions(+)
 create mode 100644 drivers/iio/position/hid-sensor-custom-intel-hinge.c

diff --git a/drivers/iio/common/hid-sensors/hid-sensor-attributes.c b/drivers/iio/common/hid-sensors/hid-sensor-attributes.c
index 442ff787f7af..5b822a4298a0 100644
--- a/drivers/iio/common/hid-sensors/hid-sensor-attributes.c
+++ b/drivers/iio/common/hid-sensors/hid-sensor-attributes.c
@@ -71,6 +71,8 @@ static struct {
 	{HID_USAGE_SENSOR_TEMPERATURE, HID_USAGE_SENSOR_UNITS_DEGREES, 1000, 0},
 
 	{HID_USAGE_SENSOR_HUMIDITY, 0, 1000, 0},
+	{HID_USAGE_SENSOR_HINGE, 0, 0, 17453293},
+	{HID_USAGE_SENSOR_HINGE, HID_USAGE_SENSOR_UNITS_DEGREES, 0, 17453293},
 };
 
 static void simple_div(int dividend, int divisor, int *whole,
diff --git a/drivers/iio/position/Kconfig b/drivers/iio/position/Kconfig
index eda67f008c5b..1576a6380b53 100644
--- a/drivers/iio/position/Kconfig
+++ b/drivers/iio/position/Kconfig
@@ -16,4 +16,20 @@ config IQS624_POS
 	  To compile this driver as a module, choose M here: the module
 	  will be called iqs624-pos.
 
+config HID_SENSOR_CUSTOM_INTEL_HINGE
+	depends on HID_SENSOR_HUB
+	select IIO_BUFFER
+	select IIO_TRIGGERED_BUFFER
+	select HID_SENSOR_IIO_COMMON
+	select HID_SENSOR_IIO_TRIGGER
+	tristate "HID Hinge"
+	help
+	  This sensor present three angles, hinge angel, screen angles
+	  and keyboard angle respect to horizon (ground).
+	  Say yes here to build support for the HID custom
+	  intel hinge sensor.
+
+	  To compile this driver as a module, choose M here: the
+	  module will be called hid-sensor-custom-hinge.
+
 endmenu
diff --git a/drivers/iio/position/Makefile b/drivers/iio/position/Makefile
index 3cbe7a734352..d70902f2979d 100644
--- a/drivers/iio/position/Makefile
+++ b/drivers/iio/position/Makefile
@@ -4,4 +4,5 @@
 
 # When adding new entries keep the list in alphabetical order
 
+obj-$(CONFIG_HID_SENSOR_CUSTOM_INTEL_HINGE) += hid-sensor-custom-intel-hinge.o
 obj-$(CONFIG_IQS624_POS)	+= iqs624-pos.o
diff --git a/drivers/iio/position/hid-sensor-custom-intel-hinge.c b/drivers/iio/position/hid-sensor-custom-intel-hinge.c
new file mode 100644
index 000000000000..24cf31c039a3
--- /dev/null
+++ b/drivers/iio/position/hid-sensor-custom-intel-hinge.c
@@ -0,0 +1,391 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * HID Sensors Driver
+ * Copyright (c) 2020, Intel Corporation.
+ */
+#include <linux/hid-sensor-hub.h>
+#include <linux/iio/buffer.h>
+#include <linux/iio/iio.h>
+#include <linux/platform_device.h>
+
+#include "../common/hid-sensors/hid-sensor-trigger.h"
+
+enum hinge_channel {
+	CHANNEL_SCAN_INDEX_HINGE_ANGLE,
+	CHANNEL_SCAN_INDEX_SCREEN_ANGLE,
+	CHANNEL_SCAN_INDEX_KEYBOARD_ANGLE,
+	CHANNEL_SCAN_INDEX_MAX,
+};
+
+#define CHANNEL_SCAN_INDEX_TIMESTAMP CHANNEL_SCAN_INDEX_MAX
+
+static const u32 hinge_addresses[CHANNEL_SCAN_INDEX_MAX] = {
+	HID_USAGE_SENSOR_DATA_FIELD_CUSTOM_VALUE(1),
+	HID_USAGE_SENSOR_DATA_FIELD_CUSTOM_VALUE(2),
+	HID_USAGE_SENSOR_DATA_FIELD_CUSTOM_VALUE(3)
+};
+
+static const char *const hinge_labels[CHANNEL_SCAN_INDEX_MAX] = { "hinge",
+								  "screen",
+								  "keyboard" };
+
+struct hinge_state {
+	struct iio_dev *indio_dev;
+	struct hid_sensor_hub_attribute_info hinge[CHANNEL_SCAN_INDEX_MAX];
+	struct hid_sensor_hub_callbacks callbacks;
+	struct hid_sensor_common common_attributes;
+	const char *labels[CHANNEL_SCAN_INDEX_MAX];
+	struct {
+		u32 hinge_val[3];
+		u64 timestamp __aligned(8);
+	} scan;
+
+	int scale_pre_decml;
+	int scale_post_decml;
+	int scale_precision;
+	int value_offset;
+	u64 timestamp;
+};
+
+/* Channel definitions */
+static const struct iio_chan_spec hinge_channels[] = {
+	{
+		.type = IIO_ANGL,
+		.indexed = 1,
+		.channel = 0,
+		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
+		.info_mask_shared_by_type =
+			BIT(IIO_CHAN_INFO_OFFSET) | BIT(IIO_CHAN_INFO_SCALE) |
+			BIT(IIO_CHAN_INFO_SAMP_FREQ) | BIT(IIO_CHAN_INFO_HYSTERESIS),
+		.scan_index = CHANNEL_SCAN_INDEX_HINGE_ANGLE,
+		.scan_type = {
+			.sign = 's',
+			.storagebits = 32,
+		},
+	}, {
+		.type = IIO_ANGL,
+		.indexed = 1,
+		.channel = 1,
+		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
+		.info_mask_shared_by_type =
+			BIT(IIO_CHAN_INFO_OFFSET) | BIT(IIO_CHAN_INFO_SCALE) |
+			BIT(IIO_CHAN_INFO_SAMP_FREQ) | BIT(IIO_CHAN_INFO_HYSTERESIS),
+		.scan_index = CHANNEL_SCAN_INDEX_SCREEN_ANGLE,
+		.scan_type = {
+			.sign = 's',
+			.storagebits = 32,
+		},
+	}, {
+		.type = IIO_ANGL,
+		.indexed = 1,
+		.channel = 2,
+		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
+		.info_mask_shared_by_type =
+			BIT(IIO_CHAN_INFO_OFFSET) | BIT(IIO_CHAN_INFO_SCALE) |
+			BIT(IIO_CHAN_INFO_SAMP_FREQ) | BIT(IIO_CHAN_INFO_HYSTERESIS),
+		.scan_index = CHANNEL_SCAN_INDEX_KEYBOARD_ANGLE,
+		.scan_type = {
+			.sign = 's',
+			.storagebits = 32,
+		},
+	},
+	IIO_CHAN_SOFT_TIMESTAMP(CHANNEL_SCAN_INDEX_TIMESTAMP)
+};
+
+/* Adjust channel real bits based on report descriptor */
+static void hinge_adjust_channel_realbits(struct iio_chan_spec *channels,
+					  int channel, int size)
+{
+	channels[channel].scan_type.realbits = size * 8;
+}
+
+/* Channel read_raw handler */
+static int hinge_read_raw(struct iio_dev *indio_dev,
+			  struct iio_chan_spec const *chan, int *val, int *val2,
+			  long mask)
+{
+	struct hinge_state *st = iio_priv(indio_dev);
+	struct hid_sensor_hub_device *hsdev;
+	int report_id;
+	int ret_type;
+	s32 min;
+
+	hsdev = st->common_attributes.hsdev;
+	switch (mask) {
+	case IIO_CHAN_INFO_RAW:
+		hid_sensor_power_state(&st->common_attributes, true);
+		report_id = st->hinge[chan->scan_index].report_id;
+		min = st->hinge[chan->scan_index].logical_minimum;
+		if (report_id < 0) {
+			hid_sensor_power_state(&st->common_attributes, false);
+			return -EINVAL;
+		}
+
+		*val = sensor_hub_input_attr_get_raw_value(st->common_attributes.hsdev,
+							   hsdev->usage,
+							   hinge_addresses[chan->scan_index],
+							   report_id,
+							   SENSOR_HUB_SYNC, min < 0);
+
+		hid_sensor_power_state(&st->common_attributes, false);
+		return IIO_VAL_INT;
+	case IIO_CHAN_INFO_SCALE:
+		*val = st->scale_pre_decml;
+		*val2 = st->scale_post_decml;
+		return st->scale_precision;
+	case IIO_CHAN_INFO_OFFSET:
+		*val = st->value_offset;
+		return IIO_VAL_INT;
+	case IIO_CHAN_INFO_SAMP_FREQ:
+		ret_type = hid_sensor_read_samp_freq_value(&st->common_attributes,
+							   val, val2);
+		return ret_type;
+	case IIO_CHAN_INFO_HYSTERESIS:
+		ret_type = hid_sensor_read_raw_hyst_value(&st->common_attributes,
+							  val, val2);
+		return ret_type;
+	default:
+		return -EINVAL;
+	}
+}
+
+/* Channel write_raw handler */
+static int hinge_write_raw(struct iio_dev *indio_dev,
+			   struct iio_chan_spec const *chan, int val, int val2,
+			   long mask)
+{
+	struct hinge_state *st = iio_priv(indio_dev);
+	int ret;
+
+	switch (mask) {
+	case IIO_CHAN_INFO_SAMP_FREQ:
+		ret = hid_sensor_write_samp_freq_value(&st->common_attributes,
+						       val, val2);
+		return ret;
+	case IIO_CHAN_INFO_HYSTERESIS:
+		ret = hid_sensor_write_raw_hyst_value(&st->common_attributes,
+						      val, val2);
+
+		return ret;
+	default:
+		return -EINVAL;
+	}
+}
+
+static int hinge_read_label(struct iio_dev *indio_dev,
+			    struct iio_chan_spec const *chan, char *label)
+{
+	struct hinge_state *st = iio_priv(indio_dev);
+
+	return sprintf(label, "%s\n", st->labels[chan->channel]);
+}
+
+static const struct iio_info hinge_info = {
+	.read_raw = hinge_read_raw,
+	.write_raw = hinge_write_raw,
+	.read_label = hinge_read_label,
+};
+
+/*
+ * Callback handler to send event after all samples are received
+ * and captured.
+ */
+static int hinge_proc_event(struct hid_sensor_hub_device *hsdev,
+			    unsigned int usage_id, void *priv)
+{
+	struct iio_dev *indio_dev = platform_get_drvdata(priv);
+	struct hinge_state *st = iio_priv(indio_dev);
+
+	if (atomic_read(&st->common_attributes.data_ready)) {
+		if (!st->timestamp)
+			st->timestamp = iio_get_time_ns(indio_dev);
+
+		iio_push_to_buffers_with_timestamp(indio_dev, &st->scan,
+						   st->timestamp);
+
+		st->timestamp = 0;
+	}
+	return 0;
+}
+
+/* Capture samples in local storage */
+static int hinge_capture_sample(struct hid_sensor_hub_device *hsdev,
+				unsigned int usage_id, size_t raw_len,
+				char *raw_data, void *priv)
+{
+	struct iio_dev *indio_dev = platform_get_drvdata(priv);
+	struct hinge_state *st = iio_priv(indio_dev);
+	int offset;
+
+	switch (usage_id) {
+	case HID_USAGE_SENSOR_DATA_FIELD_CUSTOM_VALUE(1):
+	case HID_USAGE_SENSOR_DATA_FIELD_CUSTOM_VALUE(2):
+	case HID_USAGE_SENSOR_DATA_FIELD_CUSTOM_VALUE(3):
+		offset = usage_id - HID_USAGE_SENSOR_DATA_FIELD_CUSTOM_VALUE(1);
+		st->scan.hinge_val[offset] = *(u32 *)raw_data;
+		return 0;
+	case HID_USAGE_SENSOR_TIME_TIMESTAMP:
+		st->timestamp = hid_sensor_convert_timestamp(&st->common_attributes,
+							     *(int64_t *)raw_data);
+		return 0;
+	default:
+		return -EINVAL;
+	}
+}
+
+/* Parse report which is specific to an usage id */
+static int hinge_parse_report(struct platform_device *pdev,
+			      struct hid_sensor_hub_device *hsdev,
+			      struct iio_chan_spec *channels,
+			      unsigned int usage_id, struct hinge_state *st)
+{
+	int ret;
+	int i;
+
+	for (i = 0; i < CHANNEL_SCAN_INDEX_MAX; ++i) {
+		ret = sensor_hub_input_get_attribute_info(hsdev,
+							  HID_INPUT_REPORT,
+							  usage_id,
+							  hinge_addresses[i],
+							  &st->hinge[i]);
+		if (ret < 0)
+			return ret;
+
+		hinge_adjust_channel_realbits(channels, i, st->hinge[i].size);
+	}
+
+	st->scale_precision = hid_sensor_format_scale(HID_USAGE_SENSOR_HINGE,
+			&st->hinge[CHANNEL_SCAN_INDEX_HINGE_ANGLE],
+			&st->scale_pre_decml, &st->scale_post_decml);
+
+	/* Set Sensitivity field ids, when there is no individual modifier */
+	if (st->common_attributes.sensitivity.index < 0) {
+		sensor_hub_input_get_attribute_info(hsdev,
+				HID_FEATURE_REPORT, usage_id,
+				HID_USAGE_SENSOR_DATA_MOD_CHANGE_SENSITIVITY_ABS |
+					HID_USAGE_SENSOR_DATA_FIELD_CUSTOM_VALUE(1),
+				&st->common_attributes.sensitivity);
+		dev_dbg(&pdev->dev, "Sensitivity index:report %d:%d\n",
+			st->common_attributes.sensitivity.index,
+			st->common_attributes.sensitivity.report_id);
+	}
+
+	return ret;
+}
+
+/* Function to initialize the processing for usage id */
+static int hid_hinge_probe(struct platform_device *pdev)
+{
+	struct hinge_state *st;
+	struct iio_dev *indio_dev;
+	struct hid_sensor_hub_device *hsdev = pdev->dev.platform_data;
+	int ret;
+	int i;
+
+	indio_dev = devm_iio_device_alloc(&pdev->dev, sizeof(*st));
+	if (!indio_dev)
+		return -ENOMEM;
+
+	platform_set_drvdata(pdev, indio_dev);
+
+	st = iio_priv(indio_dev);
+	st->common_attributes.hsdev = hsdev;
+	st->common_attributes.pdev = pdev;
+	st->indio_dev = indio_dev;
+	for (i = 0; i < CHANNEL_SCAN_INDEX_MAX; i++)
+		st->labels[i] = hinge_labels[i];
+
+	ret = hid_sensor_parse_common_attributes(hsdev, hsdev->usage,
+						 &st->common_attributes);
+	if (ret) {
+		dev_err(&pdev->dev, "failed to setup common attributes\n");
+		return ret;
+	}
+
+	indio_dev->num_channels = ARRAY_SIZE(hinge_channels);
+	indio_dev->channels = devm_kmemdup(&indio_dev->dev, hinge_channels,
+					   sizeof(hinge_channels), GFP_KERNEL);
+	if (!indio_dev->channels)
+		return -ENOMEM;
+
+	ret = hinge_parse_report(pdev, hsdev,
+				 (struct iio_chan_spec *)indio_dev->channels,
+				 hsdev->usage, st);
+	if (ret) {
+		dev_err(&pdev->dev, "failed to setup attributes\n");
+		return ret;
+	}
+
+	indio_dev->dev.parent = &pdev->dev;
+	indio_dev->info = &hinge_info;
+	indio_dev->name = "hinge";
+	indio_dev->modes = INDIO_DIRECT_MODE;
+
+	atomic_set(&st->common_attributes.data_ready, 0);
+	ret = hid_sensor_setup_trigger(indio_dev, indio_dev->name,
+				       &st->common_attributes);
+	if (ret < 0) {
+		dev_err(&pdev->dev, "trigger setup failed\n");
+		return ret;
+	}
+
+	st->callbacks.send_event = hinge_proc_event;
+	st->callbacks.capture_sample = hinge_capture_sample;
+	st->callbacks.pdev = pdev;
+	ret = sensor_hub_register_callback(hsdev, hsdev->usage, &st->callbacks);
+	if (ret < 0) {
+		dev_err(&pdev->dev, "callback reg failed\n");
+		goto error_remove_trigger;
+	}
+
+	ret = devm_iio_device_register(&pdev->dev, indio_dev);
+	if (ret) {
+		dev_err(&pdev->dev, "device register failed\n");
+		goto error_remove_callback;
+	}
+
+	return ret;
+
+error_remove_callback:
+	sensor_hub_remove_callback(hsdev, hsdev->usage);
+error_remove_trigger:
+	hid_sensor_remove_trigger(indio_dev, &st->common_attributes);
+	return ret;
+}
+
+/* Function to deinitialize the processing for usage id */
+static int hid_hinge_remove(struct platform_device *pdev)
+{
+	struct hid_sensor_hub_device *hsdev = pdev->dev.platform_data;
+	struct iio_dev *indio_dev = platform_get_drvdata(pdev);
+	struct hinge_state *st = iio_priv(indio_dev);
+
+	sensor_hub_remove_callback(hsdev, hsdev->usage);
+	hid_sensor_remove_trigger(indio_dev, &st->common_attributes);
+
+	return 0;
+}
+
+static const struct platform_device_id hid_hinge_ids[] = {
+	{
+		/* Format: HID-SENSOR-INT-usage_id_in_hex_lowercase */
+		.name = "HID-SENSOR-INT-020b",
+	},
+	{ /* sentinel */ }
+};
+MODULE_DEVICE_TABLE(platform, hid_hinge_ids);
+
+static struct platform_driver hid_hinge_platform_driver = {
+	.id_table = hid_hinge_ids,
+	.driver = {
+		.name	= KBUILD_MODNAME,
+		.pm	= &hid_sensor_pm_ops,
+	},
+	.probe		= hid_hinge_probe,
+	.remove		= hid_hinge_remove,
+};
+module_platform_driver(hid_hinge_platform_driver);
+
+MODULE_DESCRIPTION("HID Sensor INTEL Hinge");
+MODULE_AUTHOR("Ye Xiang <xiang.ye@intel.com>");
+MODULE_LICENSE("GPL");
-- 
2.17.1

[PATCH v4 3/3] iio:Documentation: Add documentation for hinge sensor channels

[Ye Xiang]

Add channel description for hinge sensor, including channel label
attribute and raw data description.

Signed-off-by: Ye Xiang <xiang.ye@intel.com>
---
 Documentation/ABI/testing/sysfs-bus-iio | 11 +++++++++++
 1 file changed, 11 insertions(+)

diff --git a/Documentation/ABI/testing/sysfs-bus-iio b/Documentation/ABI/testing/sysfs-bus-iio
index df42bed09f25..5c0a84c50d43 100644
--- a/Documentation/ABI/testing/sysfs-bus-iio
+++ b/Documentation/ABI/testing/sysfs-bus-iio
@@ -198,6 +198,7 @@ Description:
 		Units after application of scale and offset are m/s^2.
 
 What:		/sys/bus/iio/devices/iio:deviceX/in_angl_raw
+What:		/sys/bus/iio/devices/iio:deviceX/in_anglY_raw
 KernelVersion:	4.17
 Contact:	linux-iio@vger.kernel.org
 Description:
@@ -1802,3 +1803,13 @@ Contact:	linux-iio@vger.kernel.org
 Description:
 		Unscaled light intensity according to CIE 1931/DIN 5033 color space.
 		Units after application of scale are nano nanowatts per square meter.
+
+What:		/sys/bus/iio/devices/iio:deviceX/in_anglY_label
+KernelVersion:	5.12
+Contact:	linux-iio@vger.kernel.org
+Description:
+		Optional symbolic label for channel Y.
+		For Intel hid hinge sensor, the label values are:
+		hinge, keyboard, screen. It means the three channels
+		each correspond respectively to hinge angle, keyboard angle,
+		and screen angle.
-- 
2.17.1

Re: [PATCH v4 2/3] iio: hid-sensors: Add hinge sensor driver

[Jonathan Cameron]

On Tue, 15 Dec 2020 13:44:43 +0800
Ye Xiang <xiang.ye@intel.com> wrote:

> The Hinge sensor is a common custom sensor on laptops. It calculates
> the angle between the lid (screen) and the base (keyboard). In addition,
> it also exposes screen and the keyboard angles with respect to the
> ground. Applications can easily get laptop's status in space through
> this sensor, in order to display appropriate user interface.
> 
> Signed-off-by: Ye Xiang <xiang.ye@intel.com>
Hi.

A few things spotted on a fresh read through.  If this is all that comes
up in this round of review, I can tidy them up whilst applying.
If you are doing a v5 for any reason, please fix them up whilst doing that.

Thanks,

Jonathan

> ---
>  .../hid-sensors/hid-sensor-attributes.c       |   2 +
>  drivers/iio/position/Kconfig                  |  16 +
>  drivers/iio/position/Makefile                 |   1 +
>  .../position/hid-sensor-custom-intel-hinge.c  | 391 ++++++++++++++++++
>  4 files changed, 410 insertions(+)
>  create mode 100644 drivers/iio/position/hid-sensor-custom-intel-hinge.c
> 
> diff --git a/drivers/iio/common/hid-sensors/hid-sensor-attributes.c b/drivers/iio/common/hid-sensors/hid-sensor-attributes.c
> index 442ff787f7af..5b822a4298a0 100644
> --- a/drivers/iio/common/hid-sensors/hid-sensor-attributes.c
> +++ b/drivers/iio/common/hid-sensors/hid-sensor-attributes.c
> @@ -71,6 +71,8 @@ static struct {
>  	{HID_USAGE_SENSOR_TEMPERATURE, HID_USAGE_SENSOR_UNITS_DEGREES, 1000, 0},
>  
>  	{HID_USAGE_SENSOR_HUMIDITY, 0, 1000, 0},
> +	{HID_USAGE_SENSOR_HINGE, 0, 0, 17453293},
> +	{HID_USAGE_SENSOR_HINGE, HID_USAGE_SENSOR_UNITS_DEGREES, 0, 17453293},
>  };
>  
>  static void simple_div(int dividend, int divisor, int *whole,
> diff --git a/drivers/iio/position/Kconfig b/drivers/iio/position/Kconfig
> index eda67f008c5b..1576a6380b53 100644
> --- a/drivers/iio/position/Kconfig
> +++ b/drivers/iio/position/Kconfig
> @@ -16,4 +16,20 @@ config IQS624_POS
>  	  To compile this driver as a module, choose M here: the module
>  	  will be called iqs624-pos.
>  
> +config HID_SENSOR_CUSTOM_INTEL_HINGE
> +	depends on HID_SENSOR_HUB
> +	select IIO_BUFFER
> +	select IIO_TRIGGERED_BUFFER
> +	select HID_SENSOR_IIO_COMMON
> +	select HID_SENSOR_IIO_TRIGGER
> +	tristate "HID Hinge"
> +	help
> +	  This sensor present three angles, hinge angel, screen angles
> +	  and keyboard angle respect to horizon (ground).
> +	  Say yes here to build support for the HID custom
> +	  intel hinge sensor.
> +
> +	  To compile this driver as a module, choose M here: the
> +	  module will be called hid-sensor-custom-hinge.
> +
>  endmenu
> diff --git a/drivers/iio/position/Makefile b/drivers/iio/position/Makefile
> index 3cbe7a734352..d70902f2979d 100644
> --- a/drivers/iio/position/Makefile
> +++ b/drivers/iio/position/Makefile
> @@ -4,4 +4,5 @@
>  
>  # When adding new entries keep the list in alphabetical order
>  
> +obj-$(CONFIG_HID_SENSOR_CUSTOM_INTEL_HINGE) += hid-sensor-custom-intel-hinge.o
>  obj-$(CONFIG_IQS624_POS)	+= iqs624-pos.o
> diff --git a/drivers/iio/position/hid-sensor-custom-intel-hinge.c b/drivers/iio/position/hid-sensor-custom-intel-hinge.c
> new file mode 100644
> index 000000000000..24cf31c039a3
> --- /dev/null
> +++ b/drivers/iio/position/hid-sensor-custom-intel-hinge.c
> @@ -0,0 +1,391 @@
> +// SPDX-License-Identifier: GPL-2.0-only
> +/*
> + * HID Sensors Driver
> + * Copyright (c) 2020, Intel Corporation.
> + */
> +#include <linux/hid-sensor-hub.h>
> +#include <linux/iio/buffer.h>
> +#include <linux/iio/iio.h>
> +#include <linux/platform_device.h>
> +
> +#include "../common/hid-sensors/hid-sensor-trigger.h"
> +
> +enum hinge_channel {
> +	CHANNEL_SCAN_INDEX_HINGE_ANGLE,
> +	CHANNEL_SCAN_INDEX_SCREEN_ANGLE,
> +	CHANNEL_SCAN_INDEX_KEYBOARD_ANGLE,
> +	CHANNEL_SCAN_INDEX_MAX,
> +};
> +
> +#define CHANNEL_SCAN_INDEX_TIMESTAMP CHANNEL_SCAN_INDEX_MAX
> +
> +static const u32 hinge_addresses[CHANNEL_SCAN_INDEX_MAX] = {
> +	HID_USAGE_SENSOR_DATA_FIELD_CUSTOM_VALUE(1),
> +	HID_USAGE_SENSOR_DATA_FIELD_CUSTOM_VALUE(2),
> +	HID_USAGE_SENSOR_DATA_FIELD_CUSTOM_VALUE(3)
> +};
> +
> +static const char *const hinge_labels[CHANNEL_SCAN_INDEX_MAX] = { "hinge",
> +								  "screen",
> +								  "keyboard" };
> +
> +struct hinge_state {
> +	struct iio_dev *indio_dev;
> +	struct hid_sensor_hub_attribute_info hinge[CHANNEL_SCAN_INDEX_MAX];
> +	struct hid_sensor_hub_callbacks callbacks;
> +	struct hid_sensor_common common_attributes;
> +	const char *labels[CHANNEL_SCAN_INDEX_MAX];
> +	struct {
> +		u32 hinge_val[3];
> +		u64 timestamp __aligned(8);
> +	} scan;
> +
> +	int scale_pre_decml;
> +	int scale_post_decml;
> +	int scale_precision;
> +	int value_offset;
> +	u64 timestamp;
> +};
> +
> +/* Channel definitions */
> +static const struct iio_chan_spec hinge_channels[] = {
> +	{
> +		.type = IIO_ANGL,
> +		.indexed = 1,
> +		.channel = 0,
> +		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
> +		.info_mask_shared_by_type =
> +			BIT(IIO_CHAN_INFO_OFFSET) | BIT(IIO_CHAN_INFO_SCALE) |
> +			BIT(IIO_CHAN_INFO_SAMP_FREQ) | BIT(IIO_CHAN_INFO_HYSTERESIS),
> +		.scan_index = CHANNEL_SCAN_INDEX_HINGE_ANGLE,
> +		.scan_type = {
> +			.sign = 's',
> +			.storagebits = 32,
> +		},
> +	}, {
> +		.type = IIO_ANGL,
> +		.indexed = 1,
> +		.channel = 1,
> +		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
> +		.info_mask_shared_by_type =
> +			BIT(IIO_CHAN_INFO_OFFSET) | BIT(IIO_CHAN_INFO_SCALE) |
> +			BIT(IIO_CHAN_INFO_SAMP_FREQ) | BIT(IIO_CHAN_INFO_HYSTERESIS),
> +		.scan_index = CHANNEL_SCAN_INDEX_SCREEN_ANGLE,
> +		.scan_type = {
> +			.sign = 's',
> +			.storagebits = 32,
> +		},
> +	}, {
> +		.type = IIO_ANGL,
> +		.indexed = 1,
> +		.channel = 2,
> +		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
> +		.info_mask_shared_by_type =
> +			BIT(IIO_CHAN_INFO_OFFSET) | BIT(IIO_CHAN_INFO_SCALE) |
> +			BIT(IIO_CHAN_INFO_SAMP_FREQ) | BIT(IIO_CHAN_INFO_HYSTERESIS),
> +		.scan_index = CHANNEL_SCAN_INDEX_KEYBOARD_ANGLE,
> +		.scan_type = {
> +			.sign = 's',
> +			.storagebits = 32,
> +		},
> +	},
> +	IIO_CHAN_SOFT_TIMESTAMP(CHANNEL_SCAN_INDEX_TIMESTAMP)
> +};
> +
> +/* Adjust channel real bits based on report descriptor */
> +static void hinge_adjust_channel_realbits(struct iio_chan_spec *channels,
> +					  int channel, int size)
> +{
> +	channels[channel].scan_type.realbits = size * 8;
> +}
> +
> +/* Channel read_raw handler */
> +static int hinge_read_raw(struct iio_dev *indio_dev,
> +			  struct iio_chan_spec const *chan, int *val, int *val2,
> +			  long mask)
> +{
> +	struct hinge_state *st = iio_priv(indio_dev);
> +	struct hid_sensor_hub_device *hsdev;
> +	int report_id;
> +	int ret_type;
> +	s32 min;
> +
> +	hsdev = st->common_attributes.hsdev;
> +	switch (mask) {
> +	case IIO_CHAN_INFO_RAW:
> +		hid_sensor_power_state(&st->common_attributes, true);
> +		report_id = st->hinge[chan->scan_index].report_id;
> +		min = st->hinge[chan->scan_index].logical_minimum;
> +		if (report_id < 0) {
> +			hid_sensor_power_state(&st->common_attributes, false);
> +			return -EINVAL;
> +		}
> +
> +		*val = sensor_hub_input_attr_get_raw_value(st->common_attributes.hsdev,
> +							   hsdev->usage,
> +							   hinge_addresses[chan->scan_index],
> +							   report_id,
> +							   SENSOR_HUB_SYNC, min < 0);
> +
> +		hid_sensor_power_state(&st->common_attributes, false);
> +		return IIO_VAL_INT;
> +	case IIO_CHAN_INFO_SCALE:
> +		*val = st->scale_pre_decml;
> +		*val2 = st->scale_post_decml;
> +		return st->scale_precision;
> +	case IIO_CHAN_INFO_OFFSET:
> +		*val = st->value_offset;
> +		return IIO_VAL_INT;
> +	case IIO_CHAN_INFO_SAMP_FREQ:
> +		ret_type = hid_sensor_read_samp_freq_value(&st->common_attributes,
> +							   val, val2);
> +		return ret_type;
> +	case IIO_CHAN_INFO_HYSTERESIS:
> +		ret_type = hid_sensor_read_raw_hyst_value(&st->common_attributes,
> +							  val, val2);
> +		return ret_type;

As below, I would return directly rather than use the local variable.

> +	default:
> +		return -EINVAL;
> +	}
> +}
> +
> +/* Channel write_raw handler */
> +static int hinge_write_raw(struct iio_dev *indio_dev,
> +			   struct iio_chan_spec const *chan, int val, int val2,
> +			   long mask)
> +{
> +	struct hinge_state *st = iio_priv(indio_dev);
> +	int ret;
> +
> +	switch (mask) {
> +	case IIO_CHAN_INFO_SAMP_FREQ:
> +		ret = hid_sensor_write_samp_freq_value(&st->common_attributes,
> +						       val, val2);
> +		return ret;

If you happen to be respinning I'd go with the slightly shorter option of...

		return hid_sensor_write_samp_freq_value(&st->common_attributes,

> +	case IIO_CHAN_INFO_HYSTERESIS:
> +		ret = hid_sensor_write_raw_hyst_value(&st->common_attributes,
> +						      val, val2);
> +
> +		return ret;
> +	default:
> +		return -EINVAL;
> +	}
> +}
> +
> +static int hinge_read_label(struct iio_dev *indio_dev,
> +			    struct iio_chan_spec const *chan, char *label)
> +{
> +	struct hinge_state *st = iio_priv(indio_dev);
> +
> +	return sprintf(label, "%s\n", st->labels[chan->channel]);
> +}
> +
> +static const struct iio_info hinge_info = {
> +	.read_raw = hinge_read_raw,
> +	.write_raw = hinge_write_raw,
> +	.read_label = hinge_read_label,
> +};
> +
> +/*
> + * Callback handler to send event after all samples are received
> + * and captured.
> + */
> +static int hinge_proc_event(struct hid_sensor_hub_device *hsdev,
> +			    unsigned int usage_id, void *priv)
> +{
> +	struct iio_dev *indio_dev = platform_get_drvdata(priv);
> +	struct hinge_state *st = iio_priv(indio_dev);
> +
> +	if (atomic_read(&st->common_attributes.data_ready)) {
> +		if (!st->timestamp)
> +			st->timestamp = iio_get_time_ns(indio_dev);
> +
> +		iio_push_to_buffers_with_timestamp(indio_dev, &st->scan,
> +						   st->timestamp);
> +
> +		st->timestamp = 0;
> +	}
> +	return 0;
> +}
> +
> +/* Capture samples in local storage */
> +static int hinge_capture_sample(struct hid_sensor_hub_device *hsdev,
> +				unsigned int usage_id, size_t raw_len,
> +				char *raw_data, void *priv)
> +{
> +	struct iio_dev *indio_dev = platform_get_drvdata(priv);
> +	struct hinge_state *st = iio_priv(indio_dev);
> +	int offset;
> +
> +	switch (usage_id) {
> +	case HID_USAGE_SENSOR_DATA_FIELD_CUSTOM_VALUE(1):
> +	case HID_USAGE_SENSOR_DATA_FIELD_CUSTOM_VALUE(2):
> +	case HID_USAGE_SENSOR_DATA_FIELD_CUSTOM_VALUE(3):
> +		offset = usage_id - HID_USAGE_SENSOR_DATA_FIELD_CUSTOM_VALUE(1);
> +		st->scan.hinge_val[offset] = *(u32 *)raw_data;
> +		return 0;
> +	case HID_USAGE_SENSOR_TIME_TIMESTAMP:
> +		st->timestamp = hid_sensor_convert_timestamp(&st->common_attributes,
> +							     *(int64_t *)raw_data);
> +		return 0;
> +	default:
> +		return -EINVAL;
> +	}
> +}
> +
> +/* Parse report which is specific to an usage id */
> +static int hinge_parse_report(struct platform_device *pdev,
> +			      struct hid_sensor_hub_device *hsdev,
> +			      struct iio_chan_spec *channels,
> +			      unsigned int usage_id, struct hinge_state *st)
> +{
> +	int ret;
> +	int i;
> +
> +	for (i = 0; i < CHANNEL_SCAN_INDEX_MAX; ++i) {
> +		ret = sensor_hub_input_get_attribute_info(hsdev,
> +							  HID_INPUT_REPORT,
> +							  usage_id,
> +							  hinge_addresses[i],
> +							  &st->hinge[i]);
> +		if (ret < 0)
> +			return ret;
> +
> +		hinge_adjust_channel_realbits(channels, i, st->hinge[i].size);
> +	}
> +
> +	st->scale_precision = hid_sensor_format_scale(HID_USAGE_SENSOR_HINGE,
> +			&st->hinge[CHANNEL_SCAN_INDEX_HINGE_ANGLE],
> +			&st->scale_pre_decml, &st->scale_post_decml);
> +
> +	/* Set Sensitivity field ids, when there is no individual modifier */
> +	if (st->common_attributes.sensitivity.index < 0) {
> +		sensor_hub_input_get_attribute_info(hsdev,
> +				HID_FEATURE_REPORT, usage_id,
> +				HID_USAGE_SENSOR_DATA_MOD_CHANGE_SENSITIVITY_ABS |
> +					HID_USAGE_SENSOR_DATA_FIELD_CUSTOM_VALUE(1),
> +				&st->common_attributes.sensitivity);
> +		dev_dbg(&pdev->dev, "Sensitivity index:report %d:%d\n",
> +			st->common_attributes.sensitivity.index,
> +			st->common_attributes.sensitivity.report_id);
> +	}
> +
> +	return ret;
> +}
> +
> +/* Function to initialize the processing for usage id */
> +static int hid_hinge_probe(struct platform_device *pdev)
> +{
> +	struct hinge_state *st;
> +	struct iio_dev *indio_dev;
> +	struct hid_sensor_hub_device *hsdev = pdev->dev.platform_data;
> +	int ret;
> +	int i;
> +
> +	indio_dev = devm_iio_device_alloc(&pdev->dev, sizeof(*st));
> +	if (!indio_dev)
> +		return -ENOMEM;
> +
> +	platform_set_drvdata(pdev, indio_dev);
> +
> +	st = iio_priv(indio_dev);
> +	st->common_attributes.hsdev = hsdev;
> +	st->common_attributes.pdev = pdev;
> +	st->indio_dev = indio_dev;
> +	for (i = 0; i < CHANNEL_SCAN_INDEX_MAX; i++)
> +		st->labels[i] = hinge_labels[i];
> +
> +	ret = hid_sensor_parse_common_attributes(hsdev, hsdev->usage,
> +						 &st->common_attributes);
> +	if (ret) {
> +		dev_err(&pdev->dev, "failed to setup common attributes\n");
> +		return ret;
> +	}
> +
> +	indio_dev->num_channels = ARRAY_SIZE(hinge_channels);
> +	indio_dev->channels = devm_kmemdup(&indio_dev->dev, hinge_channels,
> +					   sizeof(hinge_channels), GFP_KERNEL);
> +	if (!indio_dev->channels)
> +		return -ENOMEM;
> +
> +	ret = hinge_parse_report(pdev, hsdev,
> +				 (struct iio_chan_spec *)indio_dev->channels,
> +				 hsdev->usage, st);
> +	if (ret) {
> +		dev_err(&pdev->dev, "failed to setup attributes\n");
> +		return ret;
> +	}
> +
> +	indio_dev->dev.parent = &pdev->dev;
> +	indio_dev->info = &hinge_info;
> +	indio_dev->name = "hinge";
> +	indio_dev->modes = INDIO_DIRECT_MODE;
> +
> +	atomic_set(&st->common_attributes.data_ready, 0);
> +	ret = hid_sensor_setup_trigger(indio_dev, indio_dev->name,
> +				       &st->common_attributes);
> +	if (ret < 0) {
> +		dev_err(&pdev->dev, "trigger setup failed\n");
> +		return ret;
> +	}
> +
> +	st->callbacks.send_event = hinge_proc_event;
> +	st->callbacks.capture_sample = hinge_capture_sample;
> +	st->callbacks.pdev = pdev;
> +	ret = sensor_hub_register_callback(hsdev, hsdev->usage, &st->callbacks);
> +	if (ret < 0) {
> +		dev_err(&pdev->dev, "callback reg failed\n");
> +		goto error_remove_trigger;
> +	}
> +
> +	ret = devm_iio_device_register(&pdev->dev, indio_dev);

Please don't mix devm and non devm functions.  The first time we
hit a non devm function that needs manual unwinding, then all later functions
in probe should also go the manual unwind route.

What you have here leads to a remove order which is not the precise reverse of
probe and makes it a lot harder to review for subtle race conditions. In this
case you leave the userspace interface exposed whilst removing some of the
underlying infrastructure.  I really don't want to have to figure out if
that is safe (probably isn't!)

Much better to just use iio_device_register here and
have an explicit iio_device_unregister in the remove function.

If nothing else comes up I can tidy that up whilst applying rather than
you needing to do a v5.

> +	if (ret) {
> +		dev_err(&pdev->dev, "device register failed\n");
> +		goto error_remove_callback;
> +	}
> +
> +	return ret;
> +
> +error_remove_callback:
> +	sensor_hub_remove_callback(hsdev, hsdev->usage);
> +error_remove_trigger:
> +	hid_sensor_remove_trigger(indio_dev, &st->common_attributes);
> +	return ret;
> +}
> +
> +/* Function to deinitialize the processing for usage id */
> +static int hid_hinge_remove(struct platform_device *pdev)
> +{
> +	struct hid_sensor_hub_device *hsdev = pdev->dev.platform_data;
> +	struct iio_dev *indio_dev = platform_get_drvdata(pdev);
> +	struct hinge_state *st = iio_priv(indio_dev);
> +
> +	sensor_hub_remove_callback(hsdev, hsdev->usage);
> +	hid_sensor_remove_trigger(indio_dev, &st->common_attributes);
> +
> +	return 0;
> +}
> +
> +static const struct platform_device_id hid_hinge_ids[] = {
> +	{
> +		/* Format: HID-SENSOR-INT-usage_id_in_hex_lowercase */
> +		.name = "HID-SENSOR-INT-020b",
> +	},
> +	{ /* sentinel */ }
> +};
> +MODULE_DEVICE_TABLE(platform, hid_hinge_ids);
> +
> +static struct platform_driver hid_hinge_platform_driver = {
> +	.id_table = hid_hinge_ids,
> +	.driver = {
> +		.name	= KBUILD_MODNAME,
> +		.pm	= &hid_sensor_pm_ops,
> +	},
> +	.probe		= hid_hinge_probe,
> +	.remove		= hid_hinge_remove,
> +};
> +module_platform_driver(hid_hinge_platform_driver);
> +
> +MODULE_DESCRIPTION("HID Sensor INTEL Hinge");
> +MODULE_AUTHOR("Ye Xiang <xiang.ye@intel.com>");
> +MODULE_LICENSE("GPL");

Re: [PATCH v4 0/3] add custom hinge sensor support

[Jonathan Cameron]

On Tue, 15 Dec 2020 13:44:41 +0800
Ye Xiang <xiang.ye@intel.com> wrote:

> Here we register one iio device with three channels which present angle for
> hinge, keyboard and screen.
> 
> This driver works on devices with Intel integrated sensor hub, where
> hinge sensor is presented using a custom sensor usage id.
> 
> Here the angle is presented in degrees, which is converted to radians.

Other than those minor bits I'm happy to fix up in patch 2, this looks
good to me.  However, I'll need a Jiri Ack for the hid parts before
I apply it.  We are are early in this cycle, so no great rush given
the usual xmas slow down!

Thanks,

Jonathan

> 
> Changes since v3:
>   - hid-sensor-custom: remove sensor_inst::custom_pdev_exposed.
>   - hid-sensor-custom: use static buf, w_buf to avoid using goto in 
>     get_known_custom_sensor_index.
>   - hid-sensor-custom-intel-hinge: use devm_ prefix function instead.
>   - sysfs-bus-iio: put in_anglY_raw together with in_angl_raw.
> 
> Changes since v2:
>   - use 1 iio device instead of 3 for hinge sensor.
>   - use indexed channel instead of modified channel and added channel
>     labels.
>   - remove 2,3 patch in last version, add a document patch to describe the
>     hinge channels.
>   - hid-sensor-custom: use meaningful return value in 
>     get_known_custom_sensor_index and checked in call side.
>   - hid-sensor-ids.h: use HID_USAGE_SENSOR_DATA_FIELD_CUSTOM_VALUE(x) to 
>     define custom sensor value.
> 
> Changes since v1:
>   - fixed errors reported by lkp
> 
> Ye Xiang (3):
>   HID: hid-sensor-custom: Add custom sensor iio support
>   iio: hid-sensors: Add hinge sensor driver
>   iio:Documentation: Add documentation for hinge sensor channels
> 
>  Documentation/ABI/testing/sysfs-bus-iio       |  11 +
>  drivers/hid/hid-sensor-custom.c               | 143 +++++++
>  .../hid-sensors/hid-sensor-attributes.c       |   2 +
>  drivers/iio/position/Kconfig                  |  16 +
>  drivers/iio/position/Makefile                 |   1 +
>  .../position/hid-sensor-custom-intel-hinge.c  | 391 ++++++++++++++++++
>  include/linux/hid-sensor-ids.h                |  14 +
>  7 files changed, 578 insertions(+)
>  create mode 100644 drivers/iio/position/hid-sensor-custom-intel-hinge.c
> 

Re: [PATCH v4 0/3] add custom hinge sensor support

[Ye, Xiang]

On Wed, Dec 30, 2020 at 12:05:17PM +0000, Jonathan Cameron wrote:
> On Tue, 15 Dec 2020 13:44:41 +0800
> Ye Xiang <xiang.ye@intel.com> wrote:
> 
> > Here we register one iio device with three channels which present angle for
> > hinge, keyboard and screen.
> > 
> > This driver works on devices with Intel integrated sensor hub, where
> > hinge sensor is presented using a custom sensor usage id.
> > 
> > Here the angle is presented in degrees, which is converted to radians.
> 
> Other than those minor bits I'm happy to fix up in patch 2, this looks
> good to me.  However, I'll need a Jiri Ack for the hid parts before
> I apply it.  We are are early in this cycle, so no great rush given
> the usual xmas slow down!

Ok, let's wait Jiri to review the hid parts. Thanks for the help.

Thanks
Ye Xiang
> 
> > 
> > Changes since v3:
> >   - hid-sensor-custom: remove sensor_inst::custom_pdev_exposed.
> >   - hid-sensor-custom: use static buf, w_buf to avoid using goto in 
> >     get_known_custom_sensor_index.
> >   - hid-sensor-custom-intel-hinge: use devm_ prefix function instead.
> >   - sysfs-bus-iio: put in_anglY_raw together with in_angl_raw.
> > 
> > Changes since v2:
> >   - use 1 iio device instead of 3 for hinge sensor.
> >   - use indexed channel instead of modified channel and added channel
> >     labels.
> >   - remove 2,3 patch in last version, add a document patch to describe the
> >     hinge channels.
> >   - hid-sensor-custom: use meaningful return value in 
> >     get_known_custom_sensor_index and checked in call side.
> >   - hid-sensor-ids.h: use HID_USAGE_SENSOR_DATA_FIELD_CUSTOM_VALUE(x) to 
> >     define custom sensor value.
> > 
> > Changes since v1:
> >   - fixed errors reported by lkp
> > 
> > Ye Xiang (3):
> >   HID: hid-sensor-custom: Add custom sensor iio support
> >   iio: hid-sensors: Add hinge sensor driver
> >   iio:Documentation: Add documentation for hinge sensor channels
> > 
> >  Documentation/ABI/testing/sysfs-bus-iio       |  11 +
> >  drivers/hid/hid-sensor-custom.c               | 143 +++++++
> >  .../hid-sensors/hid-sensor-attributes.c       |   2 +
> >  drivers/iio/position/Kconfig                  |  16 +
> >  drivers/iio/position/Makefile                 |   1 +
> >  .../position/hid-sensor-custom-intel-hinge.c  | 391 ++++++++++++++++++
> >  include/linux/hid-sensor-ids.h                |  14 +
> >  7 files changed, 578 insertions(+)
> >  create mode 100644 drivers/iio/position/hid-sensor-custom-intel-hinge.c
> > 
> 

Re: [PATCH v4 1/3] HID: hid-sensor-custom: Add custom sensor iio support

[Jiri Kosina]

On Tue, 15 Dec 2020, Ye Xiang wrote:

> Currently custom sensors properties are not decoded and it is up to
> user space to interpret.
> 
> Some manufacturers already standardized the meaning of some custom sensors.
> They can be presented as a proper IIO sensor. We can identify these sensors
> based on manufacturer and serial number property in the report.
> 
> This change is identifying hinge sensor when the manufacturer is "INTEL".
> This creates a platform device so that a sensor driver can be loaded to
> process these sensors.
> 
> Signed-off-by: Ye Xiang <xiang.ye@intel.com>

Acked-by: Jiri Kosina <jkosina@suse.cz>

Jonathan, feel free to take this with the rest through your tree. Thanks,

-- 
Jiri Kosina
SUSE Labs

Re: [PATCH v4 0/3] add custom hinge sensor support

[Jonathan Cameron]

On Thu, 31 Dec 2020 10:46:40 +0800
"Ye, Xiang" <xiang.ye@intel.com> wrote:

> On Wed, Dec 30, 2020 at 12:05:17PM +0000, Jonathan Cameron wrote:
> > On Tue, 15 Dec 2020 13:44:41 +0800
> > Ye Xiang <xiang.ye@intel.com> wrote:
> >   
> > > Here we register one iio device with three channels which present angle for
> > > hinge, keyboard and screen.
> > > 
> > > This driver works on devices with Intel integrated sensor hub, where
> > > hinge sensor is presented using a custom sensor usage id.
> > > 
> > > Here the angle is presented in degrees, which is converted to radians.  
> > 
> > Other than those minor bits I'm happy to fix up in patch 2, this looks
> > good to me.  However, I'll need a Jiri Ack for the hid parts before
> > I apply it.  We are are early in this cycle, so no great rush given
> > the usual xmas slow down!  
> 
> Ok, let's wait Jiri to review the hid parts. Thanks for the help.
Series applied with the changes mentioned in review of patch 2.

Applied to the togreg branch of iio.git and pushed out as testing for
the various autobuilders to poke at it at and see if they can find
anything I missed.

Thanks,

Jonathan

> 
> Thanks
> Ye Xiang
> >   
> > > 
> > > Changes since v3:
> > >   - hid-sensor-custom: remove sensor_inst::custom_pdev_exposed.
> > >   - hid-sensor-custom: use static buf, w_buf to avoid using goto in 
> > >     get_known_custom_sensor_index.
> > >   - hid-sensor-custom-intel-hinge: use devm_ prefix function instead.
> > >   - sysfs-bus-iio: put in_anglY_raw together with in_angl_raw.
> > > 
> > > Changes since v2:
> > >   - use 1 iio device instead of 3 for hinge sensor.
> > >   - use indexed channel instead of modified channel and added channel
> > >     labels.
> > >   - remove 2,3 patch in last version, add a document patch to describe the
> > >     hinge channels.
> > >   - hid-sensor-custom: use meaningful return value in 
> > >     get_known_custom_sensor_index and checked in call side.
> > >   - hid-sensor-ids.h: use HID_USAGE_SENSOR_DATA_FIELD_CUSTOM_VALUE(x) to 
> > >     define custom sensor value.
> > > 
> > > Changes since v1:
> > >   - fixed errors reported by lkp
> > > 
> > > Ye Xiang (3):
> > >   HID: hid-sensor-custom: Add custom sensor iio support
> > >   iio: hid-sensors: Add hinge sensor driver
> > >   iio:Documentation: Add documentation for hinge sensor channels
> > > 
> > >  Documentation/ABI/testing/sysfs-bus-iio       |  11 +
> > >  drivers/hid/hid-sensor-custom.c               | 143 +++++++
> > >  .../hid-sensors/hid-sensor-attributes.c       |   2 +
> > >  drivers/iio/position/Kconfig                  |  16 +
> > >  drivers/iio/position/Makefile                 |   1 +
> > >  .../position/hid-sensor-custom-intel-hinge.c  | 391 ++++++++++++++++++
> > >  include/linux/hid-sensor-ids.h                |  14 +
> > >  7 files changed, 578 insertions(+)
> > >  create mode 100644 drivers/iio/position/hid-sensor-custom-intel-hinge.c
> > >   
> >