[Patch v2 1/3] IIO: core: Add quaternion modifier

[Patch v2 1/3] IIO: core: Add quaternion modifier

[Srinivas Pandruvada]

Added quaternion in the list of supported modifiers.

Signed-off-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
---
 drivers/iio/industrialio-core.c | 1 +
 include/linux/iio/types.h       | 1 +
 2 files changed, 2 insertions(+)

diff --git a/drivers/iio/industrialio-core.c b/drivers/iio/industrialio-core.c
index acc911a..27bb9ca 100644
--- a/drivers/iio/industrialio-core.c
+++ b/drivers/iio/industrialio-core.c
@@ -84,6 +84,7 @@ static const char * const iio_modifier_names[] = {
 	[IIO_MOD_LIGHT_RED] = "red",
 	[IIO_MOD_LIGHT_GREEN] = "green",
 	[IIO_MOD_LIGHT_BLUE] = "blue",
+	[IIO_MOD_QUATERNION] = "quaternion",
 };
 
 /* relies on pairs of these shared then separate */
diff --git a/include/linux/iio/types.h b/include/linux/iio/types.h
index 084d882..e495720 100644
--- a/include/linux/iio/types.h
+++ b/include/linux/iio/types.h
@@ -53,6 +53,7 @@ enum iio_modifier {
 	IIO_MOD_LIGHT_RED,
 	IIO_MOD_LIGHT_GREEN,
 	IIO_MOD_LIGHT_BLUE,
+	IIO_MOD_QUATERNION,
 };
 
 enum iio_event_type {
-- 
1.9.1

[Patch v2 2/3] IIO: core: Modify scan element type

[Srinivas Pandruvada]

The current scan element type uses the following format:
  [be|le]:[s|u]bits/storagebits[>>shift].
To specify multiple elements in this type, added a repeat value.
So new format is:
  [be|le]:([s|u]bits/storagebits){repeat}[>>shift].
Here repeat is specifying how may times, real/storage bits are repeating.

When repeat is value is 0 or 1, then repeat value is not used in the format,
and it will be same as existing format.

Signed-off-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
---
 drivers/iio/industrialio-buffer.c | 41 +++++++++++++++++++++++++++++++++------
 include/linux/iio/iio.h           |  9 +++++++++
 2 files changed, 44 insertions(+), 6 deletions(-)

diff --git a/drivers/iio/industrialio-buffer.c b/drivers/iio/industrialio-buffer.c
index c67d83b..598eacd 100644
--- a/drivers/iio/industrialio-buffer.c
+++ b/drivers/iio/industrialio-buffer.c
@@ -150,7 +150,16 @@ static ssize_t iio_show_fixed_type(struct device *dev,
 		type = IIO_BE;
 #endif
 	}
-	return sprintf(buf, "%s:%c%d/%d>>%u\n",
+	if (this_attr->c->scan_type.repeat > 1)
+		return sprintf(buf, "%s:(%c%d/%d){%d}>>%u\n",
+		       iio_endian_prefix[type],
+		       this_attr->c->scan_type.sign,
+		       this_attr->c->scan_type.realbits,
+		       this_attr->c->scan_type.storagebits,
+		       this_attr->c->scan_type.repeat,
+		       this_attr->c->scan_type.shift);
+		else
+			return sprintf(buf, "%s:%c%d/%d>>%u\n",
 		       iio_endian_prefix[type],
 		       this_attr->c->scan_type.sign,
 		       this_attr->c->scan_type.realbits,
@@ -475,14 +484,22 @@ static int iio_compute_scan_bytes(struct iio_dev *indio_dev,
 	for_each_set_bit(i, mask,
 			 indio_dev->masklength) {
 		ch = iio_find_channel_from_si(indio_dev, i);
-		length = ch->scan_type.storagebits / 8;
+		if (ch->scan_type.repeat > 1)
+			length = ch->scan_type.storagebits / 8 *
+				ch->scan_type.repeat;
+		else
+			length = ch->scan_type.storagebits / 8;
 		bytes = ALIGN(bytes, length);
 		bytes += length;
 	}
 	if (timestamp) {
 		ch = iio_find_channel_from_si(indio_dev,
 					      indio_dev->scan_index_timestamp);
-		length = ch->scan_type.storagebits / 8;
+		if (ch->scan_type.repeat > 1)
+			length = ch->scan_type.storagebits / 8 *
+				ch->scan_type.repeat;
+		else
+			length = ch->scan_type.storagebits / 8;
 		bytes = ALIGN(bytes, length);
 		bytes += length;
 	}
@@ -961,7 +978,11 @@ static int iio_buffer_update_demux(struct iio_dev *indio_dev,
 					       indio_dev->masklength,
 					       in_ind + 1);
 			ch = iio_find_channel_from_si(indio_dev, in_ind);
-			length = ch->scan_type.storagebits/8;
+			if (ch->scan_type.repeat > 1)
+				length = ch->scan_type.storagebits / 8 *
+					ch->scan_type.repeat;
+			else
+				length = ch->scan_type.storagebits / 8;
 			/* Make sure we are aligned */
 			in_loc += length;
 			if (in_loc % length)
@@ -973,7 +994,11 @@ static int iio_buffer_update_demux(struct iio_dev *indio_dev,
 			goto error_clear_mux_table;
 		}
 		ch = iio_find_channel_from_si(indio_dev, in_ind);
-		length = ch->scan_type.storagebits/8;
+		if (ch->scan_type.repeat > 1)
+			length = ch->scan_type.storagebits / 8 *
+				ch->scan_type.repeat;
+		else
+			length = ch->scan_type.storagebits / 8;
 		if (out_loc % length)
 			out_loc += length - out_loc % length;
 		if (in_loc % length)
@@ -994,7 +1019,11 @@ static int iio_buffer_update_demux(struct iio_dev *indio_dev,
 		}
 		ch = iio_find_channel_from_si(indio_dev,
 			indio_dev->scan_index_timestamp);
-		length = ch->scan_type.storagebits/8;
+		if (ch->scan_type.repeat > 1)
+			length = ch->scan_type.storagebits / 8 *
+				ch->scan_type.repeat;
+		else
+			length = ch->scan_type.storagebits / 8;
 		if (out_loc % length)
 			out_loc += length - out_loc % length;
 		if (in_loc % length)
diff --git a/include/linux/iio/iio.h b/include/linux/iio/iio.h
index 75a8a20..9f1483b 100644
--- a/include/linux/iio/iio.h
+++ b/include/linux/iio/iio.h
@@ -177,6 +177,14 @@ struct iio_event_spec {
  *			shift:		Shift right by this before masking out
  *					realbits.
  *			endianness:	little or big endian
+ *			repeat:		No. of times real/storage bits repeats.
+ *					By default, when repeat is set to 0
+ *					repeat value is treated as 1. When
+ *					repeat value is 0 or 1, then there is
+ *					no change in existing scan element
+ *					type, in sysfs. When set to more than
+ *					1, then the type element in sysfs will
+ *					show repeat value.
  * @info_mask_separate: What information is to be exported that is specific to
  *			this channel.
  * @info_mask_shared_by_type: What information is to be exported that is shared
@@ -219,6 +227,7 @@ struct iio_chan_spec {
 		u8	realbits;
 		u8	storagebits;
 		u8	shift;
+		u8	repeat;
 		enum iio_endian endianness;
 	} scan_type;
 	long			info_mask_separate;
-- 
1.9.1

[Patch v2 3/3] iio: hid-sensors: Added device rotation support

[Srinivas Pandruvada]

Added usage id processing for device rotation. This uses IIO
interfaces for triggered buffer to present data to user
mode.This uses HID sensor framework for registering callback
events from the sensor hub.
Data is exported to user space in the form of quaternion rotation
format.

Signed-off-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
---
 drivers/iio/orientation/Kconfig               |  12 +
 drivers/iio/orientation/Makefile              |   1 +
 drivers/iio/orientation/hid-sensor-rotation.c | 345 ++++++++++++++++++++++++++
 include/linux/hid-sensor-ids.h                |   1 +
 4 files changed, 359 insertions(+)
 create mode 100644 drivers/iio/orientation/hid-sensor-rotation.c

diff --git a/drivers/iio/orientation/Kconfig b/drivers/iio/orientation/Kconfig
index 58c62c8..e3aa1e5 100644
--- a/drivers/iio/orientation/Kconfig
+++ b/drivers/iio/orientation/Kconfig
@@ -16,4 +16,16 @@ config HID_SENSOR_INCLINOMETER_3D
 	  Say yes here to build support for the HID SENSOR
 	  Inclinometer 3D.
 
+config HID_SENSOR_DEVICE_ROTATION
+	depends on HID_SENSOR_HUB
+	select IIO_BUFFER
+	select IIO_TRIGGERED_BUFFER
+	select HID_SENSOR_IIO_COMMON
+	select HID_SENSOR_IIO_TRIGGER
+	tristate "HID Device Rotation"
+	help
+	  Say yes here to build support for the HID SENSOR
+	  device rotation. The output of a device rotation sensor
+	  is presented using quaternion format.
+
 endmenu
diff --git a/drivers/iio/orientation/Makefile b/drivers/iio/orientation/Makefile
index 2c97572..4734dab 100644
--- a/drivers/iio/orientation/Makefile
+++ b/drivers/iio/orientation/Makefile
@@ -4,3 +4,4 @@
 
 # When adding new entries keep the list in alphabetical order
 obj-$(CONFIG_HID_SENSOR_INCLINOMETER_3D) += hid-sensor-incl-3d.o
+obj-$(CONFIG_HID_SENSOR_DEVICE_ROTATION) += hid-sensor-rotation.o
diff --git a/drivers/iio/orientation/hid-sensor-rotation.c b/drivers/iio/orientation/hid-sensor-rotation.c
new file mode 100644
index 0000000..b9cbb11
--- /dev/null
+++ b/drivers/iio/orientation/hid-sensor-rotation.c
@@ -0,0 +1,345 @@
+/*
+ * HID Sensors Driver
+ * Copyright (c) 2014, Intel Corporation.
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
+ * more details.
+ */
+
+#include <linux/device.h>
+#include <linux/platform_device.h>
+#include <linux/module.h>
+#include <linux/interrupt.h>
+#include <linux/irq.h>
+#include <linux/slab.h>
+#include <linux/hid-sensor-hub.h>
+#include <linux/iio/iio.h>
+#include <linux/iio/sysfs.h>
+#include <linux/iio/buffer.h>
+#include <linux/iio/trigger_consumer.h>
+#include <linux/iio/triggered_buffer.h>
+#include "../common/hid-sensors/hid-sensor-trigger.h"
+
+#define MAX_QUATERNION_COMP	4
+
+struct dev_rot_state {
+	struct hid_sensor_hub_callbacks callbacks;
+	struct hid_sensor_common common_attributes;
+	struct hid_sensor_hub_attribute_info quaternion;
+	u32 sampled_vals[MAX_QUATERNION_COMP];
+};
+
+/* Channel definitions */
+static const struct iio_chan_spec dev_rot_channels[] = {
+	{
+		.type = IIO_ROT,
+		.modified = 1,
+		.channel2 = IIO_MOD_QUATERNION,
+		.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_OFFSET) |
+					BIT(IIO_CHAN_INFO_SAMP_FREQ) |
+					BIT(IIO_CHAN_INFO_HYSTERESIS),
+	}
+};
+
+/* Adjust channel real bits based on report descriptor */
+static void dev_rot_adjust_channel_bit_mask(struct iio_chan_spec *chan,
+						int size)
+{
+	chan->scan_type.sign = 's';
+	/* Real storage bits will change based on the report desc. */
+	chan->scan_type.realbits = size * 8;
+	/* Maximum size of a sample to capture is u32 */
+	chan->scan_type.storagebits = sizeof(u32) * 8;
+	chan->scan_type.repeat = MAX_QUATERNION_COMP;
+}
+
+/* Channel read_raw handler */
+static int dev_rot_read_raw(struct iio_dev *indio_dev,
+			      struct iio_chan_spec const *chan,
+			      int *val, int *val2,
+			      long mask)
+{
+	struct dev_rot_state *rot_state = iio_priv(indio_dev);
+	int ret_type;
+
+	*val = 0;
+	*val2 = 0;
+	switch (mask) {
+	case IIO_CHAN_INFO_OFFSET:
+		*val = hid_sensor_convert_exponent(
+			rot_state->quaternion.unit_expo);
+		ret_type = IIO_VAL_INT;
+		break;
+	case IIO_CHAN_INFO_SAMP_FREQ:
+		ret_type = hid_sensor_read_samp_freq_value(
+			&rot_state->common_attributes, val, val2);
+		break;
+	case IIO_CHAN_INFO_HYSTERESIS:
+		ret_type = hid_sensor_read_raw_hyst_value(
+			&rot_state->common_attributes, val, val2);
+		break;
+	default:
+		ret_type = -EINVAL;
+		break;
+	}
+
+	return ret_type;
+}
+
+/* Channel write_raw handler */
+static int dev_rot_write_raw(struct iio_dev *indio_dev,
+			       struct iio_chan_spec const *chan,
+			       int val,
+			       int val2,
+			       long mask)
+{
+	struct dev_rot_state *rot_state = iio_priv(indio_dev);
+	int ret;
+
+	switch (mask) {
+	case IIO_CHAN_INFO_SAMP_FREQ:
+		ret = hid_sensor_write_samp_freq_value(
+				&rot_state->common_attributes, val, val2);
+		break;
+	case IIO_CHAN_INFO_HYSTERESIS:
+		ret = hid_sensor_write_raw_hyst_value(
+				&rot_state->common_attributes, val, val2);
+		break;
+	default:
+		ret = -EINVAL;
+	}
+
+	return ret;
+}
+
+static const struct iio_info dev_rot_info = {
+	.driver_module = THIS_MODULE,
+	.read_raw = &dev_rot_read_raw,
+	.write_raw = &dev_rot_write_raw,
+};
+
+/* Function to push data to buffer */
+static void hid_sensor_push_data(struct iio_dev *indio_dev, u8 *data, int len)
+{
+	dev_dbg(&indio_dev->dev, "hid_sensor_push_data >>\n");
+	iio_push_to_buffers(indio_dev, (u8 *)data);
+	dev_dbg(&indio_dev->dev, "hid_sensor_push_data <<\n");
+
+}
+
+/* Callback handler to send event after all samples are received and captured */
+static int dev_rot_proc_event(struct hid_sensor_hub_device *hsdev,
+				unsigned usage_id,
+				void *priv)
+{
+	struct iio_dev *indio_dev = platform_get_drvdata(priv);
+	struct dev_rot_state *rot_state = iio_priv(indio_dev);
+
+	dev_dbg(&indio_dev->dev, "dev_rot_proc_event [%d]\n",
+				rot_state->common_attributes.data_ready);
+
+	if (rot_state->common_attributes.data_ready)
+		hid_sensor_push_data(indio_dev,
+				(u8 *)rot_state->sampled_vals,
+				sizeof(rot_state->sampled_vals));
+
+	return 0;
+}
+
+/* Capture samples in local storage */
+static int dev_rot_capture_sample(struct hid_sensor_hub_device *hsdev,
+				unsigned usage_id,
+				size_t raw_len, char *raw_data,
+				void *priv)
+{
+	struct iio_dev *indio_dev = platform_get_drvdata(priv);
+	struct dev_rot_state *rot_state = iio_priv(indio_dev);
+
+	if (usage_id == HID_USAGE_SENSOR_ORIENT_QUATERNION) {
+		memcpy(rot_state->sampled_vals, raw_data,
+					sizeof(rot_state->sampled_vals));
+		dev_dbg(&indio_dev->dev, "Recd Quat len:%lu::%lu\n", raw_len,
+					sizeof(rot_state->sampled_vals));
+	}
+
+	return 0;
+}
+
+/* Parse report which is specific to an usage id*/
+static int dev_rot_parse_report(struct platform_device *pdev,
+				struct hid_sensor_hub_device *hsdev,
+				struct iio_chan_spec *channels,
+				unsigned usage_id,
+				struct dev_rot_state *st)
+{
+	int ret;
+
+	ret = sensor_hub_input_get_attribute_info(hsdev,
+				HID_INPUT_REPORT,
+				usage_id,
+				HID_USAGE_SENSOR_ORIENT_QUATERNION,
+				&st->quaternion);
+	if (ret)
+		return ret;
+	dev_rot_adjust_channel_bit_mask(&channels[0],
+		st->quaternion.size / MAX_QUATERNION_COMP);
+
+	dev_dbg(&pdev->dev, "dev_rot %x:%x\n", st->quaternion.index,
+		st->quaternion.report_id);
+
+	dev_dbg(&pdev->dev, "dev_rot: attrib size %d\n",
+				st->quaternion.size);
+
+	/* 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_ORIENTATION,
+			&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 0;
+}
+
+/* Function to initialize the processing for usage id */
+static int hid_dev_rot_probe(struct platform_device *pdev)
+{
+	int ret;
+	static char *name = "dev_rotation";
+	struct iio_dev *indio_dev;
+	struct dev_rot_state *rot_state;
+	struct hid_sensor_hub_device *hsdev = pdev->dev.platform_data;
+	struct iio_chan_spec *channels;
+
+	indio_dev = devm_iio_device_alloc(&pdev->dev,
+					  sizeof(struct dev_rot_state));
+	if (indio_dev == NULL)
+		return -ENOMEM;
+
+	platform_set_drvdata(pdev, indio_dev);
+
+	rot_state = iio_priv(indio_dev);
+	rot_state->common_attributes.hsdev = hsdev;
+	rot_state->common_attributes.pdev = pdev;
+
+	ret = hid_sensor_parse_common_attributes(hsdev,
+				HID_USAGE_SENSOR_DEVICE_ORIENTATION,
+				&rot_state->common_attributes);
+	if (ret) {
+		dev_err(&pdev->dev, "failed to setup common attributes\n");
+		return ret;
+	}
+
+	channels = kmemdup(dev_rot_channels, sizeof(dev_rot_channels),
+			   GFP_KERNEL);
+	if (!channels) {
+		dev_err(&pdev->dev, "failed to duplicate channels\n");
+		return -ENOMEM;
+	}
+
+	ret = dev_rot_parse_report(pdev, hsdev, channels,
+			HID_USAGE_SENSOR_DEVICE_ORIENTATION, rot_state);
+	if (ret) {
+		dev_err(&pdev->dev, "failed to setup attributes\n");
+		goto error_free_dev_mem;
+	}
+
+	indio_dev->channels = channels;
+	indio_dev->num_channels = ARRAY_SIZE(dev_rot_channels);
+	indio_dev->dev.parent = &pdev->dev;
+	indio_dev->info = &dev_rot_info;
+	indio_dev->name = name;
+	indio_dev->modes = INDIO_DIRECT_MODE;
+
+	ret = iio_triggered_buffer_setup(indio_dev, &iio_pollfunc_store_time,
+		NULL, NULL);
+	if (ret) {
+		dev_err(&pdev->dev, "failed to initialize trigger buffer\n");
+		goto error_free_dev_mem;
+	}
+	rot_state->common_attributes.data_ready = false;
+	ret = hid_sensor_setup_trigger(indio_dev, name,
+					&rot_state->common_attributes);
+	if (ret) {
+		dev_err(&pdev->dev, "trigger setup failed\n");
+		goto error_unreg_buffer_funcs;
+	}
+
+	ret = iio_device_register(indio_dev);
+	if (ret) {
+		dev_err(&pdev->dev, "device register failed\n");
+		goto error_remove_trigger;
+	}
+
+	rot_state->callbacks.send_event = dev_rot_proc_event;
+	rot_state->callbacks.capture_sample = dev_rot_capture_sample;
+	rot_state->callbacks.pdev = pdev;
+	ret = sensor_hub_register_callback(hsdev,
+					HID_USAGE_SENSOR_DEVICE_ORIENTATION,
+					&rot_state->callbacks);
+	if (ret) {
+		dev_err(&pdev->dev, "callback reg failed\n");
+		goto error_iio_unreg;
+	}
+
+	return 0;
+
+error_iio_unreg:
+	iio_device_unregister(indio_dev);
+error_remove_trigger:
+	hid_sensor_remove_trigger(&rot_state->common_attributes);
+error_unreg_buffer_funcs:
+	iio_triggered_buffer_cleanup(indio_dev);
+error_free_dev_mem:
+	kfree(indio_dev->channels);
+	return ret;
+}
+
+/* Function to deinitialize the processing for usage id */
+static int hid_dev_rot_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 dev_rot_state *rot_state = iio_priv(indio_dev);
+
+	sensor_hub_remove_callback(hsdev, HID_USAGE_SENSOR_DEVICE_ORIENTATION);
+	iio_device_unregister(indio_dev);
+	hid_sensor_remove_trigger(&rot_state->common_attributes);
+	iio_triggered_buffer_cleanup(indio_dev);
+	kfree(indio_dev->channels);
+
+	return 0;
+}
+
+static struct platform_device_id hid_dev_rot_ids[] = {
+	{
+		/* Format: HID-SENSOR-usage_id_in_hex_lowercase */
+		.name = "HID-SENSOR-20008a",
+	},
+	{ /* sentinel */ }
+};
+MODULE_DEVICE_TABLE(platform, hid_dev_rot_ids);
+
+static struct platform_driver hid_dev_rot_platform_driver = {
+	.id_table = hid_dev_rot_ids,
+	.driver = {
+		.name	= KBUILD_MODNAME,
+		.owner	= THIS_MODULE,
+	},
+	.probe		= hid_dev_rot_probe,
+	.remove		= hid_dev_rot_remove,
+};
+module_platform_driver(hid_dev_rot_platform_driver);
+
+MODULE_DESCRIPTION("HID Sensor Device Rotation");
+MODULE_AUTHOR("Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>");
+MODULE_LICENSE("GPL");
diff --git a/include/linux/hid-sensor-ids.h b/include/linux/hid-sensor-ids.h
index beaf965..3fc44a0 100644
--- a/include/linux/hid-sensor-ids.h
+++ b/include/linux/hid-sensor-ids.h
@@ -66,6 +66,7 @@
 #define HID_USAGE_SENSOR_ORIENT_TILT_Y				0x200480
 #define HID_USAGE_SENSOR_ORIENT_TILT_Z				0x200481
 
+#define HID_USAGE_SENSOR_DEVICE_ORIENTATION			0x20008A
 #define HID_USAGE_SENSOR_ORIENT_ROTATION_MATRIX			0x200482
 #define HID_USAGE_SENSOR_ORIENT_QUATERNION			0x200483
 #define HID_USAGE_SENSOR_ORIENT_MAGN_FLUX			0x200484
-- 
1.9.1

Re: [Patch v2 2/3] IIO: core: Modify scan element type

[Jonathan Cameron]

On 04/04/14 22:30, Srinivas Pandruvada wrote:
> The current scan element type uses the following format:
>    [be|le]:[s|u]bits/storagebits[>>shift].
> To specify multiple elements in this type, added a repeat value.
> So new format is:
>    [be|le]:([s|u]bits/storagebits){repeat}[>>shift].
Hi Srinivas.  I'd missed the addition of the brackets in this string previously.
I'm not keen on this purely because it will complicate any userspace handling
code. It may be a little simplistic but how about
[be|le]:[s|u]bits/storagebits{x[repeat]}[>>shift]
I thought about moving it to the end, but it might be slightly unclear that
we are repeating the data before or after the shift (and whether the shift
inherently reduces the length of the data - which it doesn't, but that
might not stop people getting confused ;)
> Here repeat is specifying how may times, real/storage bits are repeating.
>
> When repeat is value is 0 or 1, then repeat value is not used in the format,
> and it will be same as existing format.
>
Other than the brackets vs x suggestion this looks fine to me.
> Signed-off-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
> ---
>   drivers/iio/industrialio-buffer.c | 41 +++++++++++++++++++++++++++++++++------
>   include/linux/iio/iio.h           |  9 +++++++++
>   2 files changed, 44 insertions(+), 6 deletions(-)
>
> diff --git a/drivers/iio/industrialio-buffer.c b/drivers/iio/industrialio-buffer.c
> index c67d83b..598eacd 100644
> --- a/drivers/iio/industrialio-buffer.c
> +++ b/drivers/iio/industrialio-buffer.c
> @@ -150,7 +150,16 @@ static ssize_t iio_show_fixed_type(struct device *dev,
>   		type = IIO_BE;
>   #endif
>   	}
> -	return sprintf(buf, "%s:%c%d/%d>>%u\n",
> +	if (this_attr->c->scan_type.repeat > 1)
> +		return sprintf(buf, "%s:(%c%d/%d){%d}>>%u\n",
> +		       iio_endian_prefix[type],
> +		       this_attr->c->scan_type.sign,
> +		       this_attr->c->scan_type.realbits,
> +		       this_attr->c->scan_type.storagebits,
> +		       this_attr->c->scan_type.repeat,
> +		       this_attr->c->scan_type.shift);
> +		else
> +			return sprintf(buf, "%s:%c%d/%d>>%u\n",
>   		       iio_endian_prefix[type],
>   		       this_attr->c->scan_type.sign,
>   		       this_attr->c->scan_type.realbits,
> @@ -475,14 +484,22 @@ static int iio_compute_scan_bytes(struct iio_dev *indio_dev,
>   	for_each_set_bit(i, mask,
>   			 indio_dev->masklength) {
>   		ch = iio_find_channel_from_si(indio_dev, i);
> -		length = ch->scan_type.storagebits / 8;
> +		if (ch->scan_type.repeat > 1)
> +			length = ch->scan_type.storagebits / 8 *
> +				ch->scan_type.repeat;
> +		else
> +			length = ch->scan_type.storagebits / 8;
>   		bytes = ALIGN(bytes, length);
>   		bytes += length;
>   	}
>   	if (timestamp) {
>   		ch = iio_find_channel_from_si(indio_dev,
>   					      indio_dev->scan_index_timestamp);
> -		length = ch->scan_type.storagebits / 8;
> +		if (ch->scan_type.repeat > 1)
> +			length = ch->scan_type.storagebits / 8 *
> +				ch->scan_type.repeat;
> +		else
> +			length = ch->scan_type.storagebits / 8;
>   		bytes = ALIGN(bytes, length);
>   		bytes += length;
>   	}
> @@ -961,7 +978,11 @@ static int iio_buffer_update_demux(struct iio_dev *indio_dev,
>   					       indio_dev->masklength,
>   					       in_ind + 1);
>   			ch = iio_find_channel_from_si(indio_dev, in_ind);
> -			length = ch->scan_type.storagebits/8;
> +			if (ch->scan_type.repeat > 1)
> +				length = ch->scan_type.storagebits / 8 *
> +					ch->scan_type.repeat;
> +			else
> +				length = ch->scan_type.storagebits / 8;
>   			/* Make sure we are aligned */
>   			in_loc += length;
>   			if (in_loc % length)
> @@ -973,7 +994,11 @@ static int iio_buffer_update_demux(struct iio_dev *indio_dev,
>   			goto error_clear_mux_table;
>   		}
>   		ch = iio_find_channel_from_si(indio_dev, in_ind);
> -		length = ch->scan_type.storagebits/8;
> +		if (ch->scan_type.repeat > 1)
> +			length = ch->scan_type.storagebits / 8 *
> +				ch->scan_type.repeat;
> +		else
> +			length = ch->scan_type.storagebits / 8;
>   		if (out_loc % length)
>   			out_loc += length - out_loc % length;
>   		if (in_loc % length)
> @@ -994,7 +1019,11 @@ static int iio_buffer_update_demux(struct iio_dev *indio_dev,
>   		}
>   		ch = iio_find_channel_from_si(indio_dev,
>   			indio_dev->scan_index_timestamp);
> -		length = ch->scan_type.storagebits/8;
> +		if (ch->scan_type.repeat > 1)
> +			length = ch->scan_type.storagebits / 8 *
> +				ch->scan_type.repeat;
> +		else
> +			length = ch->scan_type.storagebits / 8;
>   		if (out_loc % length)
>   			out_loc += length - out_loc % length;
>   		if (in_loc % length)
> diff --git a/include/linux/iio/iio.h b/include/linux/iio/iio.h
> index 75a8a20..9f1483b 100644
> --- a/include/linux/iio/iio.h
> +++ b/include/linux/iio/iio.h
> @@ -177,6 +177,14 @@ struct iio_event_spec {
>    *			shift:		Shift right by this before masking out
>    *					realbits.
>    *			endianness:	little or big endian
> + *			repeat:		No. of times real/storage bits repeats.
> + *					By default, when repeat is set to 0
> + *					repeat value is treated as 1. When
> + *					repeat value is 0 or 1, then there is
> + *					no change in existing scan element
> + *					type, in sysfs. When set to more than
> + *					1, then the type element in sysfs will
> + *					show repeat value.
>    * @info_mask_separate: What information is to be exported that is specific to
>    *			this channel.
>    * @info_mask_shared_by_type: What information is to be exported that is shared
> @@ -219,6 +227,7 @@ struct iio_chan_spec {
>   		u8	realbits;
>   		u8	storagebits;
>   		u8	shift;
> +		u8	repeat;
>   		enum iio_endian endianness;
>   	} scan_type;
>   	long			info_mask_separate;
>

Re: [Patch v2 3/3] iio: hid-sensors: Added device rotation support

[Jonathan Cameron]

On 04/04/14 22:30, Srinivas Pandruvada wrote:
> Added usage id processing for device rotation. This uses IIO
> interfaces for triggered buffer to present data to user
> mode.This uses HID sensor framework for registering callback
Missing space after the full stop above.  I'd just have fixed this up
but given I want you to reroll the series anyway thought I'd mention it!
> events from the sensor hub.
> Data is exported to user space in the form of quaternion rotation
> format.
>
A couple of trivial bits inline and a plea for a devm_kmemdup ;)
Otherwise looks fine to me. If you would prefer to do the read_raw_multi
at a later date then that is fine by me, though I'd prefer it was here as
sooner or later we'll get the email saying 'why can't I read this in sysfs
otherwise ;)

J
> Signed-off-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
> ---
>   drivers/iio/orientation/Kconfig               |  12 +
>   drivers/iio/orientation/Makefile              |   1 +
>   drivers/iio/orientation/hid-sensor-rotation.c | 345 ++++++++++++++++++++++++++
>   include/linux/hid-sensor-ids.h                |   1 +
>   4 files changed, 359 insertions(+)
>   create mode 100644 drivers/iio/orientation/hid-sensor-rotation.c
>
> diff --git a/drivers/iio/orientation/Kconfig b/drivers/iio/orientation/Kconfig
> index 58c62c8..e3aa1e5 100644
> --- a/drivers/iio/orientation/Kconfig
> +++ b/drivers/iio/orientation/Kconfig
> @@ -16,4 +16,16 @@ config HID_SENSOR_INCLINOMETER_3D
>   	  Say yes here to build support for the HID SENSOR
>   	  Inclinometer 3D.
>
> +config HID_SENSOR_DEVICE_ROTATION
> +	depends on HID_SENSOR_HUB
> +	select IIO_BUFFER
> +	select IIO_TRIGGERED_BUFFER
> +	select HID_SENSOR_IIO_COMMON
> +	select HID_SENSOR_IIO_TRIGGER
> +	tristate "HID Device Rotation"
> +	help
> +	  Say yes here to build support for the HID SENSOR
> +	  device rotation. The output of a device rotation sensor
> +	  is presented using quaternion format.
> +
>   endmenu
> diff --git a/drivers/iio/orientation/Makefile b/drivers/iio/orientation/Makefile
> index 2c97572..4734dab 100644
> --- a/drivers/iio/orientation/Makefile
> +++ b/drivers/iio/orientation/Makefile
> @@ -4,3 +4,4 @@
>
>   # When adding new entries keep the list in alphabetical order
>   obj-$(CONFIG_HID_SENSOR_INCLINOMETER_3D) += hid-sensor-incl-3d.o
> +obj-$(CONFIG_HID_SENSOR_DEVICE_ROTATION) += hid-sensor-rotation.o
> diff --git a/drivers/iio/orientation/hid-sensor-rotation.c b/drivers/iio/orientation/hid-sensor-rotation.c
> new file mode 100644
> index 0000000..b9cbb11
> --- /dev/null
> +++ b/drivers/iio/orientation/hid-sensor-rotation.c
> @@ -0,0 +1,345 @@
> +/*
> + * HID Sensors Driver
> + * Copyright (c) 2014, Intel Corporation.
> + *
> + * This program is free software; you can redistribute it and/or modify it
> + * under the terms and conditions of the GNU General Public License,
> + * version 2, as published by the Free Software Foundation.
> + *
> + * This program is distributed in the hope it will be useful, but WITHOUT
> + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
> + * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
> + * more details.
> + */
> +
> +#include <linux/device.h>
> +#include <linux/platform_device.h>
> +#include <linux/module.h>
> +#include <linux/interrupt.h>
> +#include <linux/irq.h>
> +#include <linux/slab.h>
> +#include <linux/hid-sensor-hub.h>
> +#include <linux/iio/iio.h>
> +#include <linux/iio/sysfs.h>
> +#include <linux/iio/buffer.h>
> +#include <linux/iio/trigger_consumer.h>
> +#include <linux/iio/triggered_buffer.h>
> +#include "../common/hid-sensors/hid-sensor-trigger.h"
> +
Err, why MAX_?  Quaternions aren't quaternions with less than 4!
> +#define MAX_QUATERNION_COMP	4
> +
> +struct dev_rot_state {
> +	struct hid_sensor_hub_callbacks callbacks;
> +	struct hid_sensor_common common_attributes;
> +	struct hid_sensor_hub_attribute_info quaternion;
> +	u32 sampled_vals[MAX_QUATERNION_COMP];
> +};
> +
> +/* Channel definitions */
> +static const struct iio_chan_spec dev_rot_channels[] = {
> +	{
> +		.type = IIO_ROT,
> +		.modified = 1,
> +		.channel2 = IIO_MOD_QUATERNION,
> +		.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_OFFSET) |
> +					BIT(IIO_CHAN_INFO_SAMP_FREQ) |
> +					BIT(IIO_CHAN_INFO_HYSTERESIS),
> +	}
> +};
> +
> +/* Adjust channel real bits based on report descriptor */
> +static void dev_rot_adjust_channel_bit_mask(struct iio_chan_spec *chan,
> +						int size)
> +{
> +	chan->scan_type.sign = 's';
> +	/* Real storage bits will change based on the report desc. */
> +	chan->scan_type.realbits = size * 8;
> +	/* Maximum size of a sample to capture is u32 */
> +	chan->scan_type.storagebits = sizeof(u32) * 8;
> +	chan->scan_type.repeat = MAX_QUATERNION_COMP;
> +}
> +
> +/* Channel read_raw handler */
> +static int dev_rot_read_raw(struct iio_dev *indio_dev,
> +			      struct iio_chan_spec const *chan,
> +			      int *val, int *val2,
> +			      long mask)
> +{
> +	struct dev_rot_state *rot_state = iio_priv(indio_dev);
> +	int ret_type;
> +
> +	*val = 0;
> +	*val2 = 0;
> +	switch (mask) {
> +	case IIO_CHAN_INFO_OFFSET:
> +		*val = hid_sensor_convert_exponent(
> +			rot_state->quaternion.unit_expo);
> +		ret_type = IIO_VAL_INT;
> +		break;
> +	case IIO_CHAN_INFO_SAMP_FREQ:
> +		ret_type = hid_sensor_read_samp_freq_value(
> +			&rot_state->common_attributes, val, val2);
> +		break;
> +	case IIO_CHAN_INFO_HYSTERESIS:
> +		ret_type = hid_sensor_read_raw_hyst_value(
> +			&rot_state->common_attributes, val, val2);
> +		break;
> +	default:
> +		ret_type = -EINVAL;
> +		break;
> +	}
> +
> +	return ret_type;
> +}
> +
> +/* Channel write_raw handler */
> +static int dev_rot_write_raw(struct iio_dev *indio_dev,
> +			       struct iio_chan_spec const *chan,
> +			       int val,
> +			       int val2,
> +			       long mask)
> +{
> +	struct dev_rot_state *rot_state = iio_priv(indio_dev);
> +	int ret;
> +
> +	switch (mask) {
> +	case IIO_CHAN_INFO_SAMP_FREQ:
> +		ret = hid_sensor_write_samp_freq_value(
> +				&rot_state->common_attributes, val, val2);
> +		break;
> +	case IIO_CHAN_INFO_HYSTERESIS:
> +		ret = hid_sensor_write_raw_hyst_value(
> +				&rot_state->common_attributes, val, val2);
> +		break;
> +	default:
> +		ret = -EINVAL;
> +	}
> +
> +	return ret;
> +}
> +
> +static const struct iio_info dev_rot_info = {
> +	.driver_module = THIS_MODULE,
> +	.read_raw = &dev_rot_read_raw,
> +	.write_raw = &dev_rot_write_raw,
> +};
> +
> +/* Function to push data to buffer */
> +static void hid_sensor_push_data(struct iio_dev *indio_dev, u8 *data, int len)
> +{
> +	dev_dbg(&indio_dev->dev, "hid_sensor_push_data >>\n");
> +	iio_push_to_buffers(indio_dev, (u8 *)data);
> +	dev_dbg(&indio_dev->dev, "hid_sensor_push_data <<\n");
> +
> +}
> +
> +/* Callback handler to send event after all samples are received and captured */
> +static int dev_rot_proc_event(struct hid_sensor_hub_device *hsdev,
> +				unsigned usage_id,
> +				void *priv)
> +{
> +	struct iio_dev *indio_dev = platform_get_drvdata(priv);
> +	struct dev_rot_state *rot_state = iio_priv(indio_dev);
> +
> +	dev_dbg(&indio_dev->dev, "dev_rot_proc_event [%d]\n",
> +				rot_state->common_attributes.data_ready);
> +
> +	if (rot_state->common_attributes.data_ready)
> +		hid_sensor_push_data(indio_dev,
> +				(u8 *)rot_state->sampled_vals,
> +				sizeof(rot_state->sampled_vals));
> +
> +	return 0;
> +}
> +
> +/* Capture samples in local storage */
> +static int dev_rot_capture_sample(struct hid_sensor_hub_device *hsdev,
> +				unsigned usage_id,
> +				size_t raw_len, char *raw_data,
> +				void *priv)
> +{
> +	struct iio_dev *indio_dev = platform_get_drvdata(priv);
> +	struct dev_rot_state *rot_state = iio_priv(indio_dev);
> +
> +	if (usage_id == HID_USAGE_SENSOR_ORIENT_QUATERNION) {
> +		memcpy(rot_state->sampled_vals, raw_data,
> +					sizeof(rot_state->sampled_vals));
> +		dev_dbg(&indio_dev->dev, "Recd Quat len:%lu::%lu\n", raw_len,
> +					sizeof(rot_state->sampled_vals));
> +	}
> +
> +	return 0;
> +}
> +
> +/* Parse report which is specific to an usage id*/
> +static int dev_rot_parse_report(struct platform_device *pdev,
> +				struct hid_sensor_hub_device *hsdev,
> +				struct iio_chan_spec *channels,
> +				unsigned usage_id,
> +				struct dev_rot_state *st)
> +{
> +	int ret;
> +
> +	ret = sensor_hub_input_get_attribute_info(hsdev,
> +				HID_INPUT_REPORT,
> +				usage_id,
> +				HID_USAGE_SENSOR_ORIENT_QUATERNION,
> +				&st->quaternion);
> +	if (ret)
> +		return ret;
a blank line here would ever so slightly improve readability.
> +	dev_rot_adjust_channel_bit_mask(&channels[0],
> +		st->quaternion.size / MAX_QUATERNION_COMP);
> +
> +	dev_dbg(&pdev->dev, "dev_rot %x:%x\n", st->quaternion.index,
> +		st->quaternion.report_id);
> +
> +	dev_dbg(&pdev->dev, "dev_rot: attrib size %d\n",
> +				st->quaternion.size);
> +
> +	/* 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_ORIENTATION,
> +			&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);
> +	}
blank line here would be nice...
> +	return 0;
> +}
> +
> +/* Function to initialize the processing for usage id */
> +static int hid_dev_rot_probe(struct platform_device *pdev)
> +{
> +	int ret;
> +	static char *name = "dev_rotation";
> +	struct iio_dev *indio_dev;
> +	struct dev_rot_state *rot_state;
> +	struct hid_sensor_hub_device *hsdev = pdev->dev.platform_data;
> +	struct iio_chan_spec *channels;
> +
> +	indio_dev = devm_iio_device_alloc(&pdev->dev,
> +					  sizeof(struct dev_rot_state));
> +	if (indio_dev == NULL)
> +		return -ENOMEM;
> +
> +	platform_set_drvdata(pdev, indio_dev);
> +
> +	rot_state = iio_priv(indio_dev);
> +	rot_state->common_attributes.hsdev = hsdev;
> +	rot_state->common_attributes.pdev = pdev;
> +
> +	ret = hid_sensor_parse_common_attributes(hsdev,
> +				HID_USAGE_SENSOR_DEVICE_ORIENTATION,
> +				&rot_state->common_attributes);
> +	if (ret) {
> +		dev_err(&pdev->dev, "failed to setup common attributes\n");
> +		return ret;
> +	}
> +
> +	channels = kmemdup(dev_rot_channels, sizeof(dev_rot_channels),
> +			   GFP_KERNEL);
Hmm.  A devm_kmemdup would be nice wouldn't it ;)
> +	if (!channels) {
> +		dev_err(&pdev->dev, "failed to duplicate channels\n");
> +		return -ENOMEM;
> +	}
> +
> +	ret = dev_rot_parse_report(pdev, hsdev, channels,
> +			HID_USAGE_SENSOR_DEVICE_ORIENTATION, rot_state);
> +	if (ret) {
> +		dev_err(&pdev->dev, "failed to setup attributes\n");
> +		goto error_free_dev_mem;
> +	}
> +
> +	indio_dev->channels = channels;
> +	indio_dev->num_channels = ARRAY_SIZE(dev_rot_channels);
> +	indio_dev->dev.parent = &pdev->dev;
> +	indio_dev->info = &dev_rot_info;
> +	indio_dev->name = name;
> +	indio_dev->modes = INDIO_DIRECT_MODE;
> +
> +	ret = iio_triggered_buffer_setup(indio_dev, &iio_pollfunc_store_time,
> +		NULL, NULL);
> +	if (ret) {
> +		dev_err(&pdev->dev, "failed to initialize trigger buffer\n");
> +		goto error_free_dev_mem;
> +	}
> +	rot_state->common_attributes.data_ready = false;
> +	ret = hid_sensor_setup_trigger(indio_dev, name,
> +					&rot_state->common_attributes);
> +	if (ret) {
> +		dev_err(&pdev->dev, "trigger setup failed\n");
> +		goto error_unreg_buffer_funcs;
> +	}
> +
> +	ret = iio_device_register(indio_dev);
> +	if (ret) {
> +		dev_err(&pdev->dev, "device register failed\n");
> +		goto error_remove_trigger;
> +	}
> +
> +	rot_state->callbacks.send_event = dev_rot_proc_event;
> +	rot_state->callbacks.capture_sample = dev_rot_capture_sample;
> +	rot_state->callbacks.pdev = pdev;
> +	ret = sensor_hub_register_callback(hsdev,
> +					HID_USAGE_SENSOR_DEVICE_ORIENTATION,
> +					&rot_state->callbacks);
> +	if (ret) {
> +		dev_err(&pdev->dev, "callback reg failed\n");
> +		goto error_iio_unreg;
> +	}
> +
> +	return 0;
> +
> +error_iio_unreg:
> +	iio_device_unregister(indio_dev);
> +error_remove_trigger:
> +	hid_sensor_remove_trigger(&rot_state->common_attributes);
> +error_unreg_buffer_funcs:
> +	iio_triggered_buffer_cleanup(indio_dev);
> +error_free_dev_mem:
> +	kfree(indio_dev->channels);
> +	return ret;
> +}
> +
> +/* Function to deinitialize the processing for usage id */
> +static int hid_dev_rot_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 dev_rot_state *rot_state = iio_priv(indio_dev);
> +
> +	sensor_hub_remove_callback(hsdev, HID_USAGE_SENSOR_DEVICE_ORIENTATION);
> +	iio_device_unregister(indio_dev);
> +	hid_sensor_remove_trigger(&rot_state->common_attributes);
> +	iio_triggered_buffer_cleanup(indio_dev);
> +	kfree(indio_dev->channels);
> +
> +	return 0;
> +}
> +
> +static struct platform_device_id hid_dev_rot_ids[] = {
> +	{
> +		/* Format: HID-SENSOR-usage_id_in_hex_lowercase */
> +		.name = "HID-SENSOR-20008a",
> +	},
> +	{ /* sentinel */ }
> +};
> +MODULE_DEVICE_TABLE(platform, hid_dev_rot_ids);
> +
> +static struct platform_driver hid_dev_rot_platform_driver = {
> +	.id_table = hid_dev_rot_ids,
> +	.driver = {
> +		.name	= KBUILD_MODNAME,
> +		.owner	= THIS_MODULE,
> +	},
> +	.probe		= hid_dev_rot_probe,
> +	.remove		= hid_dev_rot_remove,
> +};
> +module_platform_driver(hid_dev_rot_platform_driver);
> +
> +MODULE_DESCRIPTION("HID Sensor Device Rotation");
> +MODULE_AUTHOR("Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>");
> +MODULE_LICENSE("GPL");
> diff --git a/include/linux/hid-sensor-ids.h b/include/linux/hid-sensor-ids.h
> index beaf965..3fc44a0 100644
> --- a/include/linux/hid-sensor-ids.h
> +++ b/include/linux/hid-sensor-ids.h
> @@ -66,6 +66,7 @@
>   #define HID_USAGE_SENSOR_ORIENT_TILT_Y				0x200480
>   #define HID_USAGE_SENSOR_ORIENT_TILT_Z				0x200481
>
> +#define HID_USAGE_SENSOR_DEVICE_ORIENTATION			0x20008A
>   #define HID_USAGE_SENSOR_ORIENT_ROTATION_MATRIX			0x200482
>   #define HID_USAGE_SENSOR_ORIENT_QUATERNION			0x200483
>   #define HID_USAGE_SENSOR_ORIENT_MAGN_FLUX			0x200484
>