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* [PATCH v6 00/11] Cros EC sensor hub FIFO support
@ 2020-03-24 20:27 Gwendal Grignou
  2020-03-24 20:27 ` [PATCH v6 01/11] platform: chrome: sensorhub: Add " Gwendal Grignou
                   ` (11 more replies)
  0 siblings, 12 replies; 15+ messages in thread
From: Gwendal Grignou @ 2020-03-24 20:27 UTC (permalink / raw)
  To: bleung, enric.balletbo, Jonathan.Cameron
  Cc: linux-iio, linux-kernel, Gwendal Grignou

This patchset adds a sensorhub driver for spreading sensor
events coming from the Embedded controller sensor FIFO:

       +---------------+ +--------------+ +----
       | cros_ec_accel | | cros_ec_gyro | | ...
       +---------------+ +--------------+ +----
           id:0       \        id:1 |       / id:..
                 +------------------------------+
                 |       cros-ec-sensorhub      |
                 +------------------------------+
                 |           cros_ec_dev        |
                 +------------------------------+
                 | cros_ec_i2c, cros_ec_lpc, .. |
                 +------------------------------+
                                 |
                                 EC

When new sensors events are present, the EC raises and interrupt,
sensorhub reads the FIFO and uses the 'id' field to spread the event to
the proper IIO sensors. This stack is similar to the HID sensor input
stack.

The patch set allows the host to receive MEMS sensor sample
asynchronously from ChromeOS Emebedded Controller (EC).

Given the EC and the host are not synchronized, the timestamp generated
by the EC drifts and the AP interrupt latency adds variable delay.

When events arrive, the driver stores the time of the interrupt and use
that information to convert the timestamp from the EC time domain to the
AP time domain. To prevent the errors from the interrupt time variation,
a median filter smooth the timestamp generation and prevents timestamps
to go in the past.

When a batch of sensor events arrives, the sensor hub ring code spreads
the timestamps.

The buffer interaface is presentid through the IIO ABI.
And extra parameter - flush - (presents on HID and ST sensor hub
implementation) force the EC to send accumulated events in its queue,
without waiting for buffer hwfifo_timeout to expire.

To access sensor data, we can use iio_readdev like:
 iio_readdev -T 10000 -s 4 -b 2 iio:device4

When FIFO is not supported by the EC, a trigger is present in the
directory. After registering a trigger, setting sampling_frequency,
the latest data collected by the sensor will be retrieved by the host
when the trigger expires.

When cros_ec_accel_legacy driver is used, no FIFO is supported and the
sampling frequency for the accelerometers is hard coded at 10Hz.

Gwendal Grignou (11):
  platform: chrome: sensorhub: Add FIFO support
  platform: chrome: sensorhub: Add code to spread timestmap
  platform: chrome: sensorhub: Add median filter
  iio: cros_ec: Move function description to .c file
  iio: expose iio_device_set_clock
  iio: cros_ec: Register to cros_ec_sensorhub when EC supports FIFO
  iio: cros_ec: Remove pm function
  iio: cros_ec: Expose hwfifo_timeout
  iio: cros_ec: Report hwfifo_watermark_max
  iio: cros_ec: Use Hertz as unit for sampling frequency
  iio: cros_ec: flush as hwfifo attribute

 drivers/iio/accel/cros_ec_accel_legacy.c      |    8 +-
 .../cros_ec_sensors/cros_ec_lid_angle.c       |    3 +-
 .../common/cros_ec_sensors/cros_ec_sensors.c  |   13 +-
 .../cros_ec_sensors/cros_ec_sensors_core.c    |  404 +++++--
 drivers/iio/industrialio-core.c               |    8 +-
 drivers/iio/light/cros_ec_light_prox.c        |   15 +-
 drivers/iio/pressure/cros_ec_baro.c           |   14 +-
 drivers/platform/chrome/Makefile              |    4 +-
 drivers/platform/chrome/cros_ec_sensorhub.c   |  107 +-
 .../platform/chrome/cros_ec_sensorhub_ring.c  | 1002 +++++++++++++++++
 .../linux/iio/common/cros_ec_sensors_core.h   |  104 +-
 include/linux/iio/iio.h                       |    2 +
 .../linux/platform_data/cros_ec_sensorhub.h   |  166 +++
 13 files changed, 1612 insertions(+), 238 deletions(-)
 create mode 100644 drivers/platform/chrome/cros_ec_sensorhub_ring.c

-- 
2.25.1.696.g5e7596f4ac-goog


^ permalink raw reply	[flat|nested] 15+ messages in thread

* [PATCH v6 01/11] platform: chrome: sensorhub: Add FIFO support
  2020-03-24 20:27 [PATCH v6 00/11] Cros EC sensor hub FIFO support Gwendal Grignou
@ 2020-03-24 20:27 ` " Gwendal Grignou
  2020-03-25 16:28   ` Enric Balletbo i Serra
  2020-03-24 20:27 ` [PATCH v6 02/11] platform: chrome: sensorhub: Add code to spread timestmap Gwendal Grignou
                   ` (10 subsequent siblings)
  11 siblings, 1 reply; 15+ messages in thread
From: Gwendal Grignou @ 2020-03-24 20:27 UTC (permalink / raw)
  To: bleung, enric.balletbo, Jonathan.Cameron
  Cc: linux-iio, linux-kernel, Gwendal Grignou

cros_ec_sensorhub registers a listener and query motion sense FIFO,
spread to iio sensors registers.

To test, we can use libiio:
iiod&
iio_readdev -u ip:localhost -T 10000 -s 25 -b 16 cros-ec-gyro | od -x

Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Gwendal Grignou <gwendal@chromium.org>
---
Changes in v6:
- Unify function naming in cros_ec_sensorhub: cros_ec_sensorhub_ring_...
- Kernel module name is now cros-ec-sensorhub
- Remove unneceassary warning messages.

Changes in v5:
- Use a goto in cros_ec_sensorhub_ring_handler to centralize error
  handling
- Use devm_add_action_or_reset to not need a .remove entry point for
  cros_sensor_hub.
- Fix logic error in cros_ec_sensorhub_register_push_data.
- Update kernel_doc documentation.
- Remve the need for comments in variable declaration section.
Changes in v4:
- Keep defining cros_ec_sensorhub in kernel-doc format
- Fix logic error when checking if sensor index outside array.
- Check patch with --strict option
    Use sizeof(*obj) instead of sizeof(struct ...obj)
    Alignement
    Use uX instead of uintX_t
    Use !ptr instead of ptr != NULL
Changes in v3:
- Do not use ret !=
- Simplfy errpr handling by removing a goto
- Fix doxygen comments
- Replace suspend/resume entry points with regular driver entry point;
  There was an issue in the past where the sensor stack was preventing
  device to suspend, but the proper fix has been implemented in cros_ec
  code (6ad16b78a039b "platform/chrome: don't report
EC_MKBP_EVENT_SENSOR_FIFO as wakeup")
- Reduce mutex scope by checking return code outside of it.
Changes in v2:
- Do not register a .remove routinge in plaform_driver. A
  devm_action_add is added later patch IIO driver register their
callback.
- Remove double lines, add lines before return calls.
- Handle FLUSH flag from EC.

- Use ktime_t for most timestamp measurements.
- Add doxygen comments
- Cleanup timestamp collection when processing FIFO.
- Rename fifo_toggle to fifo_enable


 drivers/platform/chrome/Makefile              |   4 +-
 drivers/platform/chrome/cros_ec_sensorhub.c   | 107 +++--
 .../platform/chrome/cros_ec_sensorhub_ring.c  | 425 ++++++++++++++++++
 .../linux/platform_data/cros_ec_sensorhub.h   |  91 ++++
 4 files changed, 599 insertions(+), 28 deletions(-)
 create mode 100644 drivers/platform/chrome/cros_ec_sensorhub_ring.c

diff --git a/drivers/platform/chrome/Makefile b/drivers/platform/chrome/Makefile
index 198c155c7c4d4..1223b028cefa0 100644
--- a/drivers/platform/chrome/Makefile
+++ b/drivers/platform/chrome/Makefile
@@ -20,7 +20,9 @@ obj-$(CONFIG_CROS_EC_CHARDEV)		+= cros_ec_chardev.o
 obj-$(CONFIG_CROS_EC_LIGHTBAR)		+= cros_ec_lightbar.o
 obj-$(CONFIG_CROS_EC_VBC)		+= cros_ec_vbc.o
 obj-$(CONFIG_CROS_EC_DEBUGFS)		+= cros_ec_debugfs.o
-obj-$(CONFIG_CROS_EC_SENSORHUB)		+= cros_ec_sensorhub.o
+obj-$(CONFIG_CROS_EC_SENSORHUB)                += cros-ec-sensorhub.o
+cros-ec-sensorhub-objs                 := cros_ec_sensorhub.o
+cros-ec-sensorhub-objs                 += cros_ec_sensorhub_ring.o
 obj-$(CONFIG_CROS_EC_SYSFS)		+= cros_ec_sysfs.o
 obj-$(CONFIG_CROS_USBPD_LOGGER)		+= cros_usbpd_logger.o
 obj-$(CONFIG_CROS_USBPD_NOTIFY)		+= cros_usbpd_notify.o
diff --git a/drivers/platform/chrome/cros_ec_sensorhub.c b/drivers/platform/chrome/cros_ec_sensorhub.c
index 79fefd3bb0fa6..bbb1c8f89905d 100644
--- a/drivers/platform/chrome/cros_ec_sensorhub.c
+++ b/drivers/platform/chrome/cros_ec_sensorhub.c
@@ -50,10 +50,8 @@ static int cros_ec_sensorhub_register(struct device *dev,
 				      struct cros_ec_sensorhub *sensorhub)
 {
 	int sensor_type[MOTIONSENSE_TYPE_MAX] = { 0 };
+	struct cros_ec_command *msg = sensorhub->msg;
 	struct cros_ec_dev *ec = sensorhub->ec;
-	struct ec_params_motion_sense *params;
-	struct ec_response_motion_sense *resp;
-	struct cros_ec_command *msg;
 	int ret, i, sensor_num;
 	char *name;
 
@@ -70,22 +68,13 @@ static int cros_ec_sensorhub_register(struct device *dev,
 		return -EINVAL;
 	}
 
-	/* Prepare a message to send INFO command to each sensor. */
-	msg = kzalloc(sizeof(*msg) + max(sizeof(*params), sizeof(*resp)),
-		      GFP_KERNEL);
-	if (!msg)
-		return -ENOMEM;
-
 	msg->version = 1;
-	msg->command = EC_CMD_MOTION_SENSE_CMD + ec->cmd_offset;
-	msg->outsize = sizeof(*params);
-	msg->insize = sizeof(*resp);
-	params = (struct ec_params_motion_sense *)msg->data;
-	resp = (struct ec_response_motion_sense *)msg->data;
+	msg->insize = sizeof(struct ec_response_motion_sense);
+	msg->outsize = sizeof(struct ec_params_motion_sense);
 
 	for (i = 0; i < sensor_num; i++) {
-		params->cmd = MOTIONSENSE_CMD_INFO;
-		params->info.sensor_num = i;
+		sensorhub->params->cmd = MOTIONSENSE_CMD_INFO;
+		sensorhub->params->info.sensor_num = i;
 
 		ret = cros_ec_cmd_xfer_status(ec->ec_dev, msg);
 		if (ret < 0) {
@@ -94,7 +83,7 @@ static int cros_ec_sensorhub_register(struct device *dev,
 			continue;
 		}
 
-		switch (resp->info.type) {
+		switch (sensorhub->resp->info.type) {
 		case MOTIONSENSE_TYPE_ACCEL:
 			name = "cros-ec-accel";
 			break;
@@ -117,15 +106,16 @@ static int cros_ec_sensorhub_register(struct device *dev,
 			name = "cros-ec-activity";
 			break;
 		default:
-			dev_warn(dev, "unknown type %d\n", resp->info.type);
+			dev_warn(dev, "unknown type %d\n",
+				 sensorhub->resp->info.type);
 			continue;
 		}
 
 		ret = cros_ec_sensorhub_allocate_sensor(dev, name, i);
 		if (ret)
-			goto error;
+			return ret;
 
-		sensor_type[resp->info.type]++;
+		sensor_type[sensorhub->resp->info.type]++;
 	}
 
 	if (sensor_type[MOTIONSENSE_TYPE_ACCEL] >= 2)
@@ -137,29 +127,41 @@ static int cros_ec_sensorhub_register(struct device *dev,
 							"cros-ec-lid-angle",
 							0);
 		if (ret)
-			goto error;
+			return ret;
 	}
 
-	kfree(msg);
 	return 0;
-
-error:
-	kfree(msg);
-	return ret;
 }
 
 static int cros_ec_sensorhub_probe(struct platform_device *pdev)
 {
 	struct device *dev = &pdev->dev;
+	struct cros_ec_dev *ec = dev_get_drvdata(dev->parent);
 	struct cros_ec_sensorhub *data;
+	struct cros_ec_command *msg;
 	int ret;
 	int i;
 
+	msg = devm_kzalloc(dev, sizeof(struct cros_ec_command) +
+			   max((u16)sizeof(struct ec_params_motion_sense),
+			       ec->ec_dev->max_response), GFP_KERNEL);
+	if (!msg)
+		return -ENOMEM;
+
+	msg->command = EC_CMD_MOTION_SENSE_CMD + ec->cmd_offset;
+
 	data = devm_kzalloc(dev, sizeof(struct cros_ec_sensorhub), GFP_KERNEL);
 	if (!data)
 		return -ENOMEM;
 
-	data->ec = dev_get_drvdata(dev->parent);
+	mutex_init(&data->cmd_lock);
+
+	data->dev = dev;
+	data->ec = ec;
+	data->msg = msg;
+	data->params = (struct ec_params_motion_sense *)msg->data;
+	data->resp = (struct ec_response_motion_sense *)msg->data;
+
 	dev_set_drvdata(dev, data);
 
 	/* Check whether this EC is a sensor hub. */
@@ -180,12 +182,63 @@ static int cros_ec_sensorhub_probe(struct platform_device *pdev)
 		}
 	}
 
+	/*
+	 * If the EC does not have a FIFO, the sensors will query their data
+	 * themselves via sysfs or a software trigger.
+	 */
+	if (cros_ec_check_features(ec, EC_FEATURE_MOTION_SENSE_FIFO)) {
+		ret = cros_ec_sensorhub_ring_add(data);
+		if (ret)
+			return ret;
+		/*
+		 * The msg and its data is not under the control of the ring
+		 * handler.
+		 */
+		return devm_add_action_or_reset(dev,
+						cros_ec_sensorhub_ring_remove,
+						data);
+	}
+
+	return 0;
+}
+
+#ifdef CONFIG_PM_SLEEP
+/*
+ * When the EC is suspending, we must stop sending interrupt,
+ * we may use the same interrupt line for waking up the device.
+ * Tell the EC to stop sending non-interrupt event on the iio ring.
+ */
+static int cros_ec_sensorhub_suspend(struct device *dev)
+{
+	struct platform_device *pdev = to_platform_device(dev);
+	struct cros_ec_sensorhub *sensorhub = platform_get_drvdata(pdev);
+	struct cros_ec_dev *ec = sensorhub->ec;
+
+	if (cros_ec_check_features(ec, EC_FEATURE_MOTION_SENSE_FIFO))
+		return cros_ec_sensorhub_ring_fifo_enable(sensorhub, false);
 	return 0;
 }
 
+static int cros_ec_sensorhub_resume(struct device *dev)
+{
+	struct platform_device *pdev = to_platform_device(dev);
+	struct cros_ec_sensorhub *sensorhub = platform_get_drvdata(pdev);
+	struct cros_ec_dev *ec = sensorhub->ec;
+
+	if (cros_ec_check_features(ec, EC_FEATURE_MOTION_SENSE_FIFO))
+		return cros_ec_sensorhub_ring_fifo_enable(sensorhub, true);
+	return 0;
+}
+#endif
+
+static SIMPLE_DEV_PM_OPS(cros_ec_sensorhub_pm_ops,
+		cros_ec_sensorhub_suspend,
+		cros_ec_sensorhub_resume);
+
 static struct platform_driver cros_ec_sensorhub_driver = {
 	.driver = {
 		.name = DRV_NAME,
+		.pm = &cros_ec_sensorhub_pm_ops,
 	},
 	.probe = cros_ec_sensorhub_probe,
 };
diff --git a/drivers/platform/chrome/cros_ec_sensorhub_ring.c b/drivers/platform/chrome/cros_ec_sensorhub_ring.c
new file mode 100644
index 0000000000000..436f306899252
--- /dev/null
+++ b/drivers/platform/chrome/cros_ec_sensorhub_ring.c
@@ -0,0 +1,425 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Driver for Chrome OS EC Sensor hub FIFO.
+ *
+ * Copyright 2020 Google LLC
+ */
+
+#include <linux/delay.h>
+#include <linux/device.h>
+#include <linux/iio/iio.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/platform_data/cros_ec_commands.h>
+#include <linux/platform_data/cros_ec_proto.h>
+#include <linux/platform_data/cros_ec_sensorhub.h>
+#include <linux/platform_device.h>
+#include <linux/sort.h>
+#include <linux/slab.h>
+
+static inline int
+cros_sensorhub_send_sample(struct cros_ec_sensorhub *sensorhub,
+			   struct cros_ec_sensors_ring_sample *sample)
+{
+	cros_ec_sensorhub_push_data_cb_t cb;
+	int id = sample->sensor_id;
+	struct iio_dev *indio_dev;
+
+	if (id > CROS_EC_SENSOR_MAX)
+		return -EINVAL;
+
+	cb = sensorhub->push_data[id].push_data_cb;
+	if (!cb)
+		return 0;
+
+	indio_dev = sensorhub->push_data[id].indio_dev;
+
+	if (sample->flag & MOTIONSENSE_SENSOR_FLAG_FLUSH)
+		return 0;
+
+	return cb(indio_dev, sample->vector, sample->timestamp);
+}
+
+/**
+ * cros_ec_sensorhub_register_push_data() - register the callback to the hub.
+ *
+ * @sensorhub : Sensor Hub object
+ * @sensor_num : The sensor the caller is interested in.
+ * @indio_dev : The iio device to use when a sample arrives.
+ * @cb : The callback to call when a sample arrives.
+ *
+ * The callback cb will be used by cros_ec_sensorhub_ring to distribute events
+ * from the EC.
+ *
+ * Return: 0 when callback is registered.
+ *         EINVAL is the sensor number is invalid or the slot already used.
+ */
+int cros_ec_sensorhub_register_push_data(struct cros_ec_sensorhub *sensorhub,
+					 u8 sensor_num,
+					 struct iio_dev *indio_dev,
+					 cros_ec_sensorhub_push_data_cb_t cb)
+{
+	if (sensor_num >= CROS_EC_SENSOR_PDEV_MAX)
+		return -EINVAL;
+	if (sensorhub->push_data[sensor_num].indio_dev)
+		return -EINVAL;
+
+	sensorhub->push_data[sensor_num].indio_dev = indio_dev;
+	sensorhub->push_data[sensor_num].push_data_cb = cb;
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(cros_ec_sensorhub_register_push_data);
+
+void cros_ec_sensorhub_unregister_push_data(struct cros_ec_sensorhub *sensorhub,
+					    u8 sensor_num)
+{
+	sensorhub->push_data[sensor_num].indio_dev = NULL;
+	sensorhub->push_data[sensor_num].push_data_cb = NULL;
+}
+EXPORT_SYMBOL_GPL(cros_ec_sensorhub_unregister_push_data);
+
+/**
+ * cros_ec_sensorhub_ring_fifo_enable() - Enable or disable interrupt generation
+ *					  for FIFO events.
+ * @sensorhub: Sensor Hub object
+ * @on: true when events are requested.
+ *
+ * To be called before sleeping or when noone is listening.
+ * Return: 0 on success, or an error when we can not communicate with the EC.
+ *
+ */
+int cros_ec_sensorhub_ring_fifo_enable(struct cros_ec_sensorhub *sensorhub,
+				       bool on)
+{
+	int ret;
+
+	mutex_lock(&sensorhub->cmd_lock);
+	sensorhub->params->cmd = MOTIONSENSE_CMD_FIFO_INT_ENABLE;
+	sensorhub->params->fifo_int_enable.enable = on;
+
+	sensorhub->msg->outsize = sizeof(struct ec_params_motion_sense);
+	sensorhub->msg->insize = sizeof(struct ec_response_motion_sense);
+
+	ret = cros_ec_cmd_xfer_status(sensorhub->ec->ec_dev, sensorhub->msg);
+	mutex_unlock(&sensorhub->cmd_lock);
+
+	/* We expect to receive a payload of 4 bytes, ignore. */
+	if (ret > 0)
+		ret = 0;
+
+	return ret;
+}
+
+/**
+ * cros_ec_sensor_ring_process_event() - process one EC FIFO event
+ *
+ * @sensorhub: Sensor Hub object.
+ * @fifo_info: FIFO information from the EC (includes b point, EC timebase).
+ * @fifo_timestamp: EC IRQ, kernel timebase (aka c).
+ * @current_timestamp: calculated event timestamp, kernel timebase (aka a').
+ * @in: incoming FIFO event from EC (includes a point, EC timebase).
+ * @out: outgoing event to user space (includes a').
+ *
+ * Process one EC event, add it in the ring if necessary.
+ *
+ * Return: true if out event has been populated.
+ */
+static bool
+cros_ec_sensor_ring_process_event(struct cros_ec_sensorhub *sensorhub,
+				  const struct cros_ec_fifo_info *fifo_info,
+				  const ktime_t fifo_timestamp,
+				  ktime_t *current_timestamp,
+				  struct ec_response_motion_sensor_data *in,
+				  struct cros_ec_sensors_ring_sample *out)
+{
+	const s64 now = cros_ec_get_time_ns();
+	int axis, async_flags;
+
+	/* Do not populate the filter based on asynchronous events. */
+	async_flags = in->flags &
+		(MOTIONSENSE_SENSOR_FLAG_ODR | MOTIONSENSE_SENSOR_FLAG_FLUSH);
+
+	if (in->flags & MOTIONSENSE_SENSOR_FLAG_TIMESTAMP && !async_flags) {
+		s64 new_timestamp;
+
+		/*
+		 * Disable filtering since we might add more jitter
+		 * if b is in a random point in time.
+		 */
+		new_timestamp = fifo_timestamp -
+				fifo_info->info.timestamp  * 1000 +
+				in->timestamp * 1000;
+
+		/*
+		 * The timestamp can be stale if we had to use the fifo
+		 * info timestamp.
+		 */
+		if (new_timestamp - *current_timestamp > 0)
+			*current_timestamp = new_timestamp;
+	}
+
+	if (in->flags & MOTIONSENSE_SENSOR_FLAG_FLUSH) {
+		out->sensor_id = in->sensor_num;
+		out->timestamp = *current_timestamp;
+		out->flag = in->flags;
+		/*
+		 * No other payload information provided with
+		 * flush ack.
+		 */
+		return true;
+	}
+
+	if (in->flags & MOTIONSENSE_SENSOR_FLAG_TIMESTAMP)
+		/* If we just have a timestamp, skip this entry. */
+		return false;
+
+	/* Regular sample */
+	out->sensor_id = in->sensor_num;
+	if (*current_timestamp - now > 0)
+		/* If the timestamp is in the future. */
+		out->timestamp = now;
+	else
+		out->timestamp = *current_timestamp;
+
+	out->flag = in->flags;
+	for (axis = 0; axis < 3; axis++)
+		out->vector[axis] = in->data[axis];
+
+	return true;
+}
+
+/**
+ * cros_ec_sensorhub_ring_handler() - The trigger handler function
+ *
+ * @sensorhub: Sensor Hub object.
+ *
+ * Called by the notifier, process the EC sensor FIFO queue.
+ */
+static void cros_ec_sensorhub_ring_handler(struct cros_ec_sensorhub *sensorhub)
+{
+	struct cros_ec_fifo_info *fifo_info = &sensorhub->fifo_info;
+	struct cros_ec_dev *ec = sensorhub->ec;
+	ktime_t fifo_timestamp, current_timestamp;
+	int i, j, number_data, ret;
+	unsigned long sensor_mask = 0;
+	struct ec_response_motion_sensor_data *in;
+	struct cros_ec_sensors_ring_sample *out, *last_out;
+
+	mutex_lock(&sensorhub->cmd_lock);
+
+	/* Get FIFO information if there are lost vectors. */
+	if (fifo_info->info.total_lost) {
+		/* Need to retrieve the number of lost vectors per sensor */
+		sensorhub->params->cmd = MOTIONSENSE_CMD_FIFO_INFO;
+		sensorhub->msg->outsize = 1;
+		sensorhub->msg->insize =
+			sizeof(struct ec_response_motion_sense_fifo_info) +
+			sizeof(u16) * CROS_EC_SENSOR_MAX;
+
+		if (cros_ec_cmd_xfer_status(ec->ec_dev, sensorhub->msg) < 0)
+			goto error;
+
+		memcpy(fifo_info, &sensorhub->resp->fifo_info,
+		       sizeof(*fifo_info));
+
+		/*
+		 * Update collection time, will not be as precise as the
+		 * non-error case.
+		 */
+		fifo_timestamp = cros_ec_get_time_ns();
+	} else {
+		fifo_timestamp =
+			sensorhub->fifo_timestamp[CROS_EC_SENSOR_NEW_TS];
+	}
+
+	if (fifo_info->info.count > sensorhub->fifo_size ||
+	    fifo_info->info.size != sensorhub->fifo_size) {
+		dev_warn(sensorhub->dev,
+			 "Mismatch EC data: count %d, size %d - expected %d",
+			 fifo_info->info.count, fifo_info->info.size,
+			 sensorhub->fifo_size);
+		goto error;
+	}
+
+	/* Copy elements in the main fifo */
+	current_timestamp = sensorhub->fifo_timestamp[CROS_EC_SENSOR_LAST_TS];
+	out = sensorhub->ring;
+	for (i = 0; i < fifo_info->info.count; i += number_data) {
+		sensorhub->params->cmd = MOTIONSENSE_CMD_FIFO_READ;
+		sensorhub->params->fifo_read.max_data_vector =
+			fifo_info->info.count - i;
+		sensorhub->msg->outsize =
+			sizeof(struct ec_params_motion_sense);
+		sensorhub->msg->insize =
+			sizeof(sensorhub->resp->fifo_read) +
+			sensorhub->params->fifo_read.max_data_vector *
+			  sizeof(struct ec_response_motion_sensor_data);
+		ret = cros_ec_cmd_xfer_status(ec->ec_dev, sensorhub->msg);
+		if (ret < 0) {
+			dev_warn(sensorhub->dev, "Fifo error: %d\n", ret);
+			break;
+		}
+		number_data = sensorhub->resp->fifo_read.number_data;
+		if (number_data == 0) {
+			dev_dbg(sensorhub->dev, "Unexpected empty FIFO\n");
+			break;
+		}
+		if (number_data > fifo_info->info.count - i) {
+			dev_warn(sensorhub->dev,
+				 "Invalid EC data: too many entry received: %d, expected %d",
+				 number_data, fifo_info->info.count - i);
+			break;
+		}
+		if (out + number_data >
+		    sensorhub->ring + fifo_info->info.count) {
+			dev_warn(sensorhub->dev,
+				 "Too many samples: %d (%zd data) to %d entries for expected %d entries",
+				 i, out - sensorhub->ring, i + number_data,
+				 fifo_info->info.count);
+			break;
+		}
+
+		for (in = sensorhub->resp->fifo_read.data, j = 0;
+		     j < number_data; j++, in++) {
+			if (cros_ec_sensor_ring_process_event(
+						sensorhub, fifo_info,
+						fifo_timestamp,
+						&current_timestamp,
+						in, out)) {
+				sensor_mask |= BIT(in->sensor_num);
+				out++;
+			}
+		}
+	}
+	mutex_unlock(&sensorhub->cmd_lock);
+	last_out = out;
+
+	if (out == sensorhub->ring)
+		/* Unexpected empty FIFO. */
+		goto ring_handler_end;
+
+	/*
+	 * Check if current_timestamp is ahead of the last sample.
+	 * Normally, the EC appends a timestamp after the last sample, but if
+	 * the AP is slow to respond to the IRQ, the EC may have added new
+	 * samples. Use the FIFO info timestamp as last timestamp then.
+	 */
+	if ((last_out - 1)->timestamp == current_timestamp)
+		current_timestamp = fifo_timestamp;
+
+	/* Warn on lost samples. */
+	for_each_set_bit(i, &sensor_mask, BITS_PER_LONG) {
+		int total_lost = fifo_info->info.total_lost;
+
+		if (total_lost) {
+			int lost = fifo_info->lost[i];
+
+			if (lost) {
+				dev_warn_ratelimited(sensorhub->dev,
+						     "Sensor %d: lost: %d out of %d\n",
+						     i, lost, total_lost);
+			}
+		}
+	}
+
+	/* Push the event into the FIFO. */
+	for (out = sensorhub->ring; out < last_out; out++)
+		cros_sensorhub_send_sample(sensorhub, out);
+
+ring_handler_end:
+	sensorhub->fifo_timestamp[CROS_EC_SENSOR_LAST_TS] = current_timestamp;
+	return;
+
+error:
+	mutex_unlock(&sensorhub->cmd_lock);
+}
+
+static int cros_ec_sensorhub_event(struct notifier_block *nb,
+				   unsigned long queued_during_suspend,
+				   void *_notify)
+{
+	struct cros_ec_sensorhub *sensorhub;
+	struct cros_ec_device *ec_dev;
+
+	sensorhub = container_of(nb, struct cros_ec_sensorhub, notifier);
+	ec_dev = sensorhub->ec->ec_dev;
+
+	if (ec_dev->event_data.event_type != EC_MKBP_EVENT_SENSOR_FIFO)
+		return NOTIFY_DONE;
+
+	if (ec_dev->event_size != sizeof(ec_dev->event_data.data.sensor_fifo)) {
+		dev_warn(ec_dev->dev, "Invalid fifo info size\n");
+		return NOTIFY_DONE;
+	}
+
+	if (queued_during_suspend)
+		return NOTIFY_OK;
+
+	sensorhub->fifo_info.info = ec_dev->event_data.data.sensor_fifo.info;
+	sensorhub->fifo_timestamp[CROS_EC_SENSOR_NEW_TS] =
+		ec_dev->last_event_time;
+	cros_ec_sensorhub_ring_handler(sensorhub);
+
+	return NOTIFY_OK;
+}
+
+/**
+ * cros_ec_sensorhub_ring_add() - Add the FIFO functionality if the EC
+ *				  supports it.
+ *
+ * @sensorhub : Sensor Hub object.
+ *
+ * Return: 0 on success.
+ */
+int cros_ec_sensorhub_ring_add(struct cros_ec_sensorhub *sensorhub)
+{
+	struct cros_ec_dev *ec = sensorhub->ec;
+	int ret;
+
+	/* Retrieve FIFO information */
+	sensorhub->msg->version = 2;
+	sensorhub->params->cmd = MOTIONSENSE_CMD_FIFO_INFO;
+	sensorhub->msg->outsize = 1;
+	sensorhub->msg->insize =
+		sizeof(struct ec_response_motion_sense_fifo_info) +
+		sizeof(u16) * CROS_EC_SENSOR_MAX;
+
+	ret = cros_ec_cmd_xfer_status(ec->ec_dev, sensorhub->msg);
+	if (ret < 0)
+		return ret;
+
+	/*
+	 * Allocate the full fifo. We need to copy the whole FIFO to set
+	 * timestamps properly.
+	 */
+	sensorhub->fifo_size = sensorhub->resp->fifo_info.size;
+	sensorhub->ring = devm_kcalloc(sensorhub->dev, sensorhub->fifo_size,
+				       sizeof(*sensorhub->ring), GFP_KERNEL);
+	if (!sensorhub->ring)
+		return -ENOMEM;
+
+	sensorhub->fifo_timestamp[CROS_EC_SENSOR_LAST_TS] =
+		cros_ec_get_time_ns();
+
+	/* Register the notifier that will act as a top half interrupt. */
+	sensorhub->notifier.notifier_call = cros_ec_sensorhub_event;
+	ret = blocking_notifier_chain_register(&ec->ec_dev->event_notifier,
+					       &sensorhub->notifier);
+	if (ret < 0)
+		return ret;
+
+	/* Start collection samples. */
+	return cros_ec_sensorhub_ring_fifo_enable(sensorhub, true);
+}
+
+void cros_ec_sensorhub_ring_remove(void *arg)
+{
+	struct cros_ec_sensorhub *sensorhub = arg;
+	struct cros_ec_device *ec_dev = sensorhub->ec->ec_dev;
+
+	/* Disable the ring, prevent EC interrupt to the AP for nothing. */
+	cros_ec_sensorhub_ring_fifo_enable(sensorhub, false);
+	blocking_notifier_chain_unregister(&ec_dev->event_notifier,
+					   &sensorhub->notifier);
+}
diff --git a/include/linux/platform_data/cros_ec_sensorhub.h b/include/linux/platform_data/cros_ec_sensorhub.h
index bef7ffc7fce10..cb849a2da4f60 100644
--- a/include/linux/platform_data/cros_ec_sensorhub.h
+++ b/include/linux/platform_data/cros_ec_sensorhub.h
@@ -8,8 +8,22 @@
 #ifndef __LINUX_PLATFORM_DATA_CROS_EC_SENSORHUB_H
 #define __LINUX_PLATFORM_DATA_CROS_EC_SENSORHUB_H
 
+#include <linux/ktime.h>
+#include <linux/mutex.h>
+#include <linux/notifier.h>
 #include <linux/platform_data/cros_ec_commands.h>
 
+/* Maximal number of sensors supported by the EC. */
+#define CROS_EC_SENSOR_MAX 16
+
+/*
+ * Maximal number of sensors supported by the hub:
+ * We add one for the lid angle inclinometer sensor.
+ */
+#define CROS_EC_SENSOR_PDEV_MAX (CROS_EC_SENSOR_MAX + 1)
+
+struct iio_dev;
+
 /**
  * struct cros_ec_sensor_platform - ChromeOS EC sensor platform information.
  * @sensor_num: Id of the sensor, as reported by the EC.
@@ -18,13 +32,90 @@ struct cros_ec_sensor_platform {
 	u8 sensor_num;
 };
 
+/**
+ * typedef cros_ec_sensorhub_push_data_cb_t - Callback function to send datum
+ *					      to specific sensors.
+ *
+ * @indio_dev: The IIO device that will process the sample.
+ * @data: Vector array of the ring sample.
+ * @timestamp: Timestamp in host timespace when the sample was acquired by
+ *             the EC.
+ */
+typedef int (*cros_ec_sensorhub_push_data_cb_t)(struct iio_dev *indio_dev,
+						s16 *data,
+						s64 timestamp);
+
+struct cros_ec_sensorhub_sensor_push_data {
+	struct iio_dev *indio_dev;
+	cros_ec_sensorhub_push_data_cb_t push_data_cb;
+};
+
+enum {
+	CROS_EC_SENSOR_LAST_TS,
+	CROS_EC_SENSOR_NEW_TS,
+	CROS_EC_SENSOR_ALL_TS
+};
+
+struct __ec_todo_packed cros_ec_fifo_info {
+	struct ec_response_motion_sense_fifo_info info;
+	u16    lost[CROS_EC_SENSOR_MAX];
+};
+
+struct cros_ec_sensors_ring_sample {
+	u8  sensor_id;
+	u8  flag;
+	s16 vector[3];
+	s64 timestamp;
+} __packed;
+
 /**
  * struct cros_ec_sensorhub - Sensor Hub device data.
  *
+ * @dev: Device object, mostly used for logging.
  * @ec: Embedded Controller where the hub is located.
+ * @msg: Structure to send FIFO requests.
+ * @params: Pointer to parameters in msg.
+ * @resp: Pointer to responses in msg.
+ * @cmd_lock : Lock for sending msg.
+ * @notifier: Notifier to kick the FIFO interrupt.
+ * @ring: Preprocessed ring to store events.
+ * @fifo_timestamp: array for event timestamp and spreading.
+ * @fifo_info: copy of FIFO information coming from the EC.
+ * @fifo_size: size of the ring.
+ * @push_data: array of callback to send datums to iio sensor object.
  */
 struct cros_ec_sensorhub {
+	struct device *dev;
 	struct cros_ec_dev *ec;
+
+	struct cros_ec_command *msg;
+	struct ec_params_motion_sense *params;
+	struct ec_response_motion_sense *resp;
+	struct mutex cmd_lock;  /* Lock for protecting msg structure. */
+
+	struct notifier_block notifier;
+
+	struct cros_ec_sensors_ring_sample *ring;
+
+	ktime_t fifo_timestamp[CROS_EC_SENSOR_ALL_TS];
+	struct cros_ec_fifo_info fifo_info;
+	int fifo_size;
+
+	struct cros_ec_sensorhub_sensor_push_data
+		push_data[CROS_EC_SENSOR_PDEV_MAX];
 };
 
+int cros_ec_sensorhub_register_push_data(struct cros_ec_sensorhub *sensorhub,
+					 u8 sensor_num,
+					 struct iio_dev *indio_dev,
+					 cros_ec_sensorhub_push_data_cb_t cb);
+
+void cros_ec_sensorhub_unregister_push_data(struct cros_ec_sensorhub *sensorhub,
+					    u8 sensor_num);
+
+int cros_ec_sensorhub_ring_add(struct cros_ec_sensorhub *sensorhub);
+void cros_ec_sensorhub_ring_remove(void *arg);
+int cros_ec_sensorhub_ring_fifo_enable(struct cros_ec_sensorhub *sensorhub,
+				       bool on);
+
 #endif   /* __LINUX_PLATFORM_DATA_CROS_EC_SENSORHUB_H */
-- 
2.25.1.696.g5e7596f4ac-goog


^ permalink raw reply	[flat|nested] 15+ messages in thread

* [PATCH v6 02/11] platform: chrome: sensorhub: Add code to spread timestmap
  2020-03-24 20:27 [PATCH v6 00/11] Cros EC sensor hub FIFO support Gwendal Grignou
  2020-03-24 20:27 ` [PATCH v6 01/11] platform: chrome: sensorhub: Add " Gwendal Grignou
@ 2020-03-24 20:27 ` Gwendal Grignou
  2020-03-24 20:27 ` [PATCH v6 03/11] platform: chrome: sensorhub: Add median filter Gwendal Grignou
                   ` (9 subsequent siblings)
  11 siblings, 0 replies; 15+ messages in thread
From: Gwendal Grignou @ 2020-03-24 20:27 UTC (permalink / raw)
  To: bleung, enric.balletbo, Jonathan.Cameron
  Cc: linux-iio, linux-kernel, Gwendal Grignou, Lee Jones

EC FIFO can send sensor events in batch. Spread them based on
previous (TSa) and currnet timestamp (TSb)

  EC FIFO                             iio events
+-----------+
| TSa       |
+-----------+             +---------------------------------------+
| event 1   |             | event 1 | TSb - (TSb - TSa)/n * (n-1) |
+-----------+             +---------------------------------------+
| event 2   |             | event 2 | TSb - (TSb - TSa)/n * (n-2) |
+-----------+             +---------------------------------------+
|  ...      |  ------>    |  ....   |                             |
+-----------+             +---------------------------------------+
| event n-1 |             | event 2 | TSb - (TSb - TSa)/n         |
+-----------+             +---------------------------------------+
| event n   |             | event 2 | TSb                         |
+-----------+             +---------------------------------------+
| TSb       |
+-----------+

Acked-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Acked-by: Lee Jones <lee.jones@linaro.org>
Signed-off-by: Gwendal Grignou <gwendal@chromium.org>
---
Changes in v6:
  Comment fixes
Changes in v5:
  Added ack.
Changes in v4:
- Check patch with --strict option
    Alignement
No changes in v3.
Changes in v2:
- Use CROS_EC_SENSOR_LAST_TS instead of LAST_TS to avoid name colisions.

 .../platform/chrome/cros_ec_sensorhub_ring.c  | 112 ++++++++++++++++--
 1 file changed, 105 insertions(+), 7 deletions(-)

diff --git a/drivers/platform/chrome/cros_ec_sensorhub_ring.c b/drivers/platform/chrome/cros_ec_sensorhub_ring.c
index 436f306899252..efe726171bf00 100644
--- a/drivers/platform/chrome/cros_ec_sensorhub_ring.c
+++ b/drivers/platform/chrome/cros_ec_sensorhub_ring.c
@@ -189,6 +189,101 @@ cros_ec_sensor_ring_process_event(struct cros_ec_sensorhub *sensorhub,
 	return true;
 }
 
+/*
+ * cros_ec_sensor_ring_spread_add: Calculate proper timestamps then add to
+ * ringbuffer.
+ *
+ * If there is a sample with a proper timestamp
+ *
+ *                        timestamp | count
+ *                        -----------------
+ * older_unprocess_out --> TS1      | 1
+ *                         TS1      | 2
+ *                out -->  TS1      | 3
+ *           next_out -->  TS2      |
+ *
+ * We spread time for the samples [older_unprocess_out .. out]
+ * between TS1 and TS2: [TS1+1/4, TS1+2/4, TS1+3/4, TS2].
+ *
+ * If we reach the end of the samples, we compare with the
+ * current timestamp:
+ *
+ * older_unprocess_out --> TS1      | 1
+ *                         TS1      | 2
+ *                 out --> TS1      | 3
+ *
+ * We know have [TS1+1/3, TS1+2/3, current timestamp]
+ */
+static void cros_ec_sensor_ring_spread_add(struct cros_ec_sensorhub *sensorhub,
+					   unsigned long sensor_mask,
+					   s64 current_timestamp,
+					   struct cros_ec_sensors_ring_sample
+					   *last_out)
+{
+	struct cros_ec_sensors_ring_sample *out;
+	int i;
+
+	for_each_set_bit(i, &sensor_mask, BITS_PER_LONG) {
+		s64 older_timestamp;
+		s64 timestamp;
+		struct cros_ec_sensors_ring_sample *older_unprocess_out =
+			sensorhub->ring;
+		struct cros_ec_sensors_ring_sample *next_out;
+		int count = 1;
+
+		for (out = sensorhub->ring; out < last_out; out = next_out) {
+			s64 time_period;
+
+			next_out = out + 1;
+			if (out->sensor_id != i)
+				continue;
+
+			/* Timestamp to start with */
+			older_timestamp = out->timestamp;
+
+			/* Find next sample. */
+			while (next_out < last_out && next_out->sensor_id != i)
+				next_out++;
+
+			if (next_out >= last_out) {
+				timestamp = current_timestamp;
+			} else {
+				timestamp = next_out->timestamp;
+				if (timestamp == older_timestamp) {
+					count++;
+					continue;
+				}
+			}
+
+			/*
+			 * The next sample has a new timestamp, spread the
+			 * unprocessed samples.
+			 */
+			if (next_out < last_out)
+				count++;
+			time_period = div_s64(timestamp - older_timestamp,
+					      count);
+
+			for (; older_unprocess_out <= out;
+					older_unprocess_out++) {
+				if (older_unprocess_out->sensor_id != i)
+					continue;
+				older_timestamp += time_period;
+				older_unprocess_out->timestamp =
+					older_timestamp;
+			}
+			count = 1;
+			/* The next_out sample has a valid timestamp, skip. */
+			next_out++;
+			older_unprocess_out = next_out;
+		}
+	}
+
+	/* Push the event into the kfifo */
+	for (out = sensorhub->ring; out < last_out; out++)
+		cros_sensorhub_send_sample(sensorhub, out);
+}
+
 /**
  * cros_ec_sensorhub_ring_handler() - The trigger handler function
  *
@@ -300,10 +395,10 @@ static void cros_ec_sensorhub_ring_handler(struct cros_ec_sensorhub *sensorhub)
 		goto ring_handler_end;
 
 	/*
-	 * Check if current_timestamp is ahead of the last sample.
-	 * Normally, the EC appends a timestamp after the last sample, but if
-	 * the AP is slow to respond to the IRQ, the EC may have added new
-	 * samples. Use the FIFO info timestamp as last timestamp then.
+	 * Check if current_timestamp is ahead of the last sample. Normally,
+	 * the EC appends a timestamp after the last sample, but if the AP
+	 * is slow to respond to the IRQ, the EC may have added new samples.
+	 * Use the FIFO info timestamp as last timestamp then.
 	 */
 	if ((last_out - 1)->timestamp == current_timestamp)
 		current_timestamp = fifo_timestamp;
@@ -323,9 +418,12 @@ static void cros_ec_sensorhub_ring_handler(struct cros_ec_sensorhub *sensorhub)
 		}
 	}
 
-	/* Push the event into the FIFO. */
-	for (out = sensorhub->ring; out < last_out; out++)
-		cros_sensorhub_send_sample(sensorhub, out);
+	/*
+	 * Spread samples in case of batching, then add them to the
+	 * ringbuffer.
+	 */
+	cros_ec_sensor_ring_spread_add(sensorhub, sensor_mask,
+				       current_timestamp, last_out);
 
 ring_handler_end:
 	sensorhub->fifo_timestamp[CROS_EC_SENSOR_LAST_TS] = current_timestamp;
-- 
2.25.1.696.g5e7596f4ac-goog


^ permalink raw reply	[flat|nested] 15+ messages in thread

* [PATCH v6 03/11] platform: chrome: sensorhub: Add median filter
  2020-03-24 20:27 [PATCH v6 00/11] Cros EC sensor hub FIFO support Gwendal Grignou
  2020-03-24 20:27 ` [PATCH v6 01/11] platform: chrome: sensorhub: Add " Gwendal Grignou
  2020-03-24 20:27 ` [PATCH v6 02/11] platform: chrome: sensorhub: Add code to spread timestmap Gwendal Grignou
@ 2020-03-24 20:27 ` Gwendal Grignou
  2020-03-24 20:27 ` [PATCH v6 04/11] iio: cros_ec: Move function description to .c file Gwendal Grignou
                   ` (8 subsequent siblings)
  11 siblings, 0 replies; 15+ messages in thread
From: Gwendal Grignou @ 2020-03-24 20:27 UTC (permalink / raw)
  To: bleung, enric.balletbo, Jonathan.Cameron
  Cc: linux-iio, linux-kernel, Gwendal Grignou, Lee Jones

Events are timestamped in EC time space, their timestamps need to be
converted in host time space.
The assumption is the time delta between when the interrupt is sent
by the EC and when it is receive by the host is a [small] constant.
This is not always true, even with hard-wired interrupt. To mitigate
worst offenders, add a median filter to weed out bigger than expected
delays.

Acked-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Acked-by: Enric Balletbo i Serra <enric.balletbo@collabora.com>
Acked-by: Lee Jones <lee.jones@linaro.org>
Signed-off-by: Gwendal Grignou <gwendal@chromium.org>
---
Changes in v6:
- No changes.
Changes in v5:
- Enforce kernel-doc function naming.
- Added ack.
- Fix spelling
- Add ratelimiting for an error message.
- Remove unrelated code changes (line, kernel-doc)
Changes in v4:
- Keep defining cros_ec_sensorhub in kernel-doc format
- Check patch with --strict option
    Use BIT()
    Add spaces around '-'
    Alignement
Changes in v3:
- Fix doxygen code.
Changes in v2:
- Move some #define in .c to prevent name collisions.
- Add proper doxygen comments.
- Use /* instead of //

 .../platform/chrome/cros_ec_sensorhub_ring.c  | 538 +++++++++++++++++-
 .../linux/platform_data/cros_ec_sensorhub.h   |  83 ++-
 2 files changed, 591 insertions(+), 30 deletions(-)

diff --git a/drivers/platform/chrome/cros_ec_sensorhub_ring.c b/drivers/platform/chrome/cros_ec_sensorhub_ring.c
index efe726171bf00..14da503cc0559 100644
--- a/drivers/platform/chrome/cros_ec_sensorhub_ring.c
+++ b/drivers/platform/chrome/cros_ec_sensorhub_ring.c
@@ -17,6 +17,21 @@
 #include <linux/sort.h>
 #include <linux/slab.h>
 
+/* Precision of fixed point for the m values from the filter */
+#define M_PRECISION BIT(23)
+
+/* Only activate the filter once we have at least this many elements. */
+#define TS_HISTORY_THRESHOLD 8
+
+/*
+ * If we don't have any history entries for this long, empty the filter to
+ * make sure there are no big discontinuities.
+ */
+#define TS_HISTORY_BORED_US 500000
+
+/* To measure by how much the filter is overshooting, if it happens. */
+#define FUTURE_TS_ANALYTICS_COUNT_MAX 100
+
 static inline int
 cros_sensorhub_send_sample(struct cros_ec_sensorhub *sensorhub,
 			   struct cros_ec_sensors_ring_sample *sample)
@@ -92,9 +107,11 @@ EXPORT_SYMBOL_GPL(cros_ec_sensorhub_unregister_push_data);
 int cros_ec_sensorhub_ring_fifo_enable(struct cros_ec_sensorhub *sensorhub,
 				       bool on)
 {
-	int ret;
+	int ret, i;
 
 	mutex_lock(&sensorhub->cmd_lock);
+	for (i = 0; i < CROS_EC_SENSOR_MAX; i++)
+		sensorhub->last_batch_len[i] = 0;
 	sensorhub->params->cmd = MOTIONSENSE_CMD_FIFO_INT_ENABLE;
 	sensorhub->params->fifo_int_enable.enable = on;
 
@@ -111,8 +128,242 @@ int cros_ec_sensorhub_ring_fifo_enable(struct cros_ec_sensorhub *sensorhub,
 	return ret;
 }
 
+static int cros_ec_sensor_ring_median_cmp(const void *pv1, const void *pv2)
+{
+	s64 v1 = *(s64 *)pv1;
+	s64 v2 = *(s64 *)pv2;
+
+	if (v1 > v2)
+		return 1;
+	else if (v1 < v2)
+		return -1;
+	else
+		return 0;
+}
+
+/*
+ * cros_ec_sensor_ring_median: Gets median of an array of numbers
+ *
+ * For now it's implemented using an inefficient > O(n) sort then return
+ * the middle element. A more optimal method would be something like
+ * quickselect, but given that n = 64 we can probably live with it in the
+ * name of clarity.
+ *
+ * Warning: the input array gets modified (sorted)!
+ */
+static s64 cros_ec_sensor_ring_median(s64 *array, size_t length)
+{
+	sort(array, length, sizeof(s64), cros_ec_sensor_ring_median_cmp, NULL);
+	return array[length / 2];
+}
+
+/*
+ * IRQ Timestamp Filtering
+ *
+ * Lower down in cros_ec_sensor_ring_process_event(), for each sensor event
+ * we have to calculate it's timestamp in the AP timebase. There are 3 time
+ * points:
+ *   a - EC timebase, sensor event
+ *   b - EC timebase, IRQ
+ *   c - AP timebase, IRQ
+ *   a' - what we want: sensor even in AP timebase
+ *
+ * While a and b are recorded at accurate times (due to the EC real time
+ * nature); c is pretty untrustworthy, even though it's recorded the
+ * first thing in ec_irq_handler(). There is a very good change we'll get
+ * added lantency due to:
+ *   other irqs
+ *   ddrfreq
+ *   cpuidle
+ *
+ * Normally a' = c - b + a, but if we do that naive math any jitter in c
+ * will get coupled in a', which we don't want. We want a function
+ * a' = cros_ec_sensor_ring_ts_filter(a) which will filter out outliers in c.
+ *
+ * Think of a graph of AP time(b) on the y axis vs EC time(c) on the x axis.
+ * The slope of the line won't be exactly 1, there will be some clock drift
+ * between the 2 chips for various reasons (mechanical stress, temperature,
+ * voltage). We need to extrapolate values for a future x, without trusting
+ * recent y values too much.
+ *
+ * We use a median filter for the slope, then another median filter for the
+ * y-intercept to calculate this function:
+ *   dx[n] = x[n-1] - x[n]
+ *   dy[n] = x[n-1] - x[n]
+ *   m[n] = dy[n] / dx[n]
+ *   median_m = median(m[n-k:n])
+ *   error[i] = y[n-i] - median_m * x[n-i]
+ *   median_error = median(error[:k])
+ *   predicted_y = median_m * x + median_error
+ *
+ * Implementation differences from above:
+ * - Redefined y to be actually c - b, this gives us a lot more precision
+ * to do the math. (c-b)/b variations are more obvious than c/b variations.
+ * - Since we don't have floating point, any operations involving slope are
+ * done using fixed point math (*M_PRECISION)
+ * - Since x and y grow with time, we keep zeroing the graph (relative to
+ * the last sample), this way math involving *x[n-i] will not overflow
+ * - EC timestamps are kept in us, it improves the slope calculation precision
+ */
+
+/**
+ * cros_ec_sensor_ring_ts_filter_update() - Update filter history.
+ *
+ * @state: Filter information.
+ * @b: IRQ timestamp, EC timebase (us)
+ * @c: IRQ timestamp, AP timebase (ns)
+ *
+ * Given a new IRQ timestamp pair (EC and AP timebases), add it to the filter
+ * history.
+ */
+static void
+cros_ec_sensor_ring_ts_filter_update(struct cros_ec_sensors_ts_filter_state
+				     *state,
+				     s64 b, s64 c)
+{
+	s64 x, y;
+	s64 dx, dy;
+	s64 m; /* stored as *M_PRECISION */
+	s64 *m_history_copy = state->temp_buf;
+	s64 *error = state->temp_buf;
+	int i;
+
+	/* we trust b the most, that'll be our independent variable */
+	x = b;
+	/* y is the offset between AP and EC times, in ns */
+	y = c - b * 1000;
+
+	dx = (state->x_history[0] + state->x_offset) - x;
+	if (dx == 0)
+		return; /* we already have this irq in the history */
+	dy = (state->y_history[0] + state->y_offset) - y;
+	m = div64_s64(dy * M_PRECISION, dx);
+
+	/* Empty filter if we haven't seen any action in a while. */
+	if (-dx > TS_HISTORY_BORED_US)
+		state->history_len = 0;
+
+	/* Move everything over, also update offset to all absolute coords .*/
+	for (i = state->history_len - 1; i >= 1; i--) {
+		state->x_history[i] = state->x_history[i - 1] + dx;
+		state->y_history[i] = state->y_history[i - 1] + dy;
+
+		state->m_history[i] = state->m_history[i - 1];
+		/*
+		 * Also use the same loop to copy m_history for future
+		 * median extraction.
+		 */
+		m_history_copy[i] = state->m_history[i - 1];
+	}
+
+	/* Store the x and y, but remember offset is actually last sample. */
+	state->x_offset = x;
+	state->y_offset = y;
+	state->x_history[0] = 0;
+	state->y_history[0] = 0;
+
+	state->m_history[0] = m;
+	m_history_copy[0] = m;
+
+	if (state->history_len < CROS_EC_SENSORHUB_TS_HISTORY_SIZE)
+		state->history_len++;
+
+	/* Precalculate things for the filter. */
+	if (state->history_len > TS_HISTORY_THRESHOLD) {
+		state->median_m =
+		    cros_ec_sensor_ring_median(m_history_copy,
+					       state->history_len - 1);
+
+		/*
+		 * Calculate y-intercepts as if m_median is the slope and
+		 * points in the history are on the line. median_error will
+		 * still be in the offset coordinate system.
+		 */
+		for (i = 0; i < state->history_len; i++)
+			error[i] = state->y_history[i] -
+				div_s64(state->median_m * state->x_history[i],
+					M_PRECISION);
+		state->median_error =
+			cros_ec_sensor_ring_median(error, state->history_len);
+	} else {
+		state->median_m = 0;
+		state->median_error = 0;
+	}
+}
+
+/**
+ * cros_ec_sensor_ring_ts_filter() - Translate EC timebase timestamp to AP
+ *                                   timebase
+ *
+ * @state: filter information.
+ * @x: any ec timestamp (us):
+ *
+ * cros_ec_sensor_ring_ts_filter(a) => a' event timestamp, AP timebase
+ * cros_ec_sensor_ring_ts_filter(b) => calculated timestamp when the EC IRQ
+ *                           should have happened on the AP, with low jitter
+ *
+ * Note: The filter will only activate once state->history_len goes
+ * over TS_HISTORY_THRESHOLD. Otherwise it'll just do the naive c - b + a
+ * transform.
+ *
+ * How to derive the formula, starting from:
+ *   f(x) = median_m * x + median_error
+ * That's the calculated AP - EC offset (at the x point in time)
+ * Undo the coordinate system transform:
+ *   f(x) = median_m * (x - x_offset) + median_error + y_offset
+ * Remember to undo the "y = c - b * 1000" modification:
+ *   f(x) = median_m * (x - x_offset) + median_error + y_offset + x * 1000
+ *
+ * Return: timestamp in AP timebase (ns)
+ */
+static s64
+cros_ec_sensor_ring_ts_filter(struct cros_ec_sensors_ts_filter_state *state,
+			      s64 x)
+{
+	return div_s64(state->median_m * (x - state->x_offset), M_PRECISION)
+	       + state->median_error + state->y_offset + x * 1000;
+}
+
+/*
+ * Since a and b were originally 32 bit values from the EC,
+ * they overflow relatively often, casting is not enough, so we need to
+ * add an offset.
+ */
+static void
+cros_ec_sensor_ring_fix_overflow(s64 *ts,
+				 const s64 overflow_period,
+				 struct cros_ec_sensors_ec_overflow_state
+				 *state)
+{
+	s64 adjust;
+
+	*ts += state->offset;
+	if (abs(state->last - *ts) > (overflow_period / 2)) {
+		adjust = state->last > *ts ? overflow_period : -overflow_period;
+		state->offset += adjust;
+		*ts += adjust;
+	}
+	state->last = *ts;
+}
+
+static void
+cros_ec_sensor_ring_check_for_past_timestamp(struct cros_ec_sensorhub
+					     *sensorhub,
+					     struct cros_ec_sensors_ring_sample
+					     *sample)
+{
+	const u8 sensor_id = sample->sensor_id;
+
+	/* If this event is earlier than one we saw before... */
+	if (sensorhub->newest_sensor_event[sensor_id] > sample->timestamp)
+		/* mark it for spreading. */
+		sample->timestamp = sensorhub->last_batch_timestamp[sensor_id];
+	else
+		sensorhub->newest_sensor_event[sensor_id] = sample->timestamp;
+}
+
 /**
- * cros_ec_sensor_ring_process_event() - process one EC FIFO event
+ * cros_ec_sensor_ring_process_event() - Process one EC FIFO event
  *
  * @sensorhub: Sensor Hub object.
  * @fifo_info: FIFO information from the EC (includes b point, EC timebase).
@@ -141,28 +392,54 @@ cros_ec_sensor_ring_process_event(struct cros_ec_sensorhub *sensorhub,
 		(MOTIONSENSE_SENSOR_FLAG_ODR | MOTIONSENSE_SENSOR_FLAG_FLUSH);
 
 	if (in->flags & MOTIONSENSE_SENSOR_FLAG_TIMESTAMP && !async_flags) {
-		s64 new_timestamp;
+		s64 a = in->timestamp;
+		s64 b = fifo_info->info.timestamp;
+		s64 c = fifo_timestamp;
+
+		cros_ec_sensor_ring_fix_overflow(&a, 1LL << 32,
+						 &sensorhub->overflow_a);
+		cros_ec_sensor_ring_fix_overflow(&b, 1LL << 32,
+						 &sensorhub->overflow_b);
+
+		if (sensorhub->tight_timestamps) {
+			cros_ec_sensor_ring_ts_filter_update(
+					&sensorhub->filter, b, c);
+			*current_timestamp = cros_ec_sensor_ring_ts_filter(
+					&sensorhub->filter, a);
+		} else {
+			s64 new_timestamp;
 
-		/*
-		 * Disable filtering since we might add more jitter
-		 * if b is in a random point in time.
-		 */
-		new_timestamp = fifo_timestamp -
-				fifo_info->info.timestamp  * 1000 +
-				in->timestamp * 1000;
+			/*
+			 * Disable filtering since we might add more jitter
+			 * if b is in a random point in time.
+			 */
+			new_timestamp = fifo_timestamp -
+					fifo_info->info.timestamp  * 1000 +
+					in->timestamp * 1000;
+			/*
+			 * The timestamp can be stale if we had to use the fifo
+			 * info timestamp.
+			 */
+			if (new_timestamp - *current_timestamp > 0)
+				*current_timestamp = new_timestamp;
+		}
+	}
 
+	if (in->flags & MOTIONSENSE_SENSOR_FLAG_ODR) {
+		sensorhub->last_batch_len[in->sensor_num] =
+			sensorhub->penultimate_batch_len[in->sensor_num] = 0;
 		/*
-		 * The timestamp can be stale if we had to use the fifo
-		 * info timestamp.
+		 * ODR change is only useful for the sensor_ring, it does not
+		 * convey information to clients.
 		 */
-		if (new_timestamp - *current_timestamp > 0)
-			*current_timestamp = new_timestamp;
+		return false;
 	}
 
 	if (in->flags & MOTIONSENSE_SENSOR_FLAG_FLUSH) {
 		out->sensor_id = in->sensor_num;
 		out->timestamp = *current_timestamp;
 		out->flag = in->flags;
+		sensorhub->last_batch_len[out->sensor_id] = 0;
 		/*
 		 * No other payload information provided with
 		 * flush ack.
@@ -176,22 +453,220 @@ cros_ec_sensor_ring_process_event(struct cros_ec_sensorhub *sensorhub,
 
 	/* Regular sample */
 	out->sensor_id = in->sensor_num;
-	if (*current_timestamp - now > 0)
-		/* If the timestamp is in the future. */
+	if (*current_timestamp - now > 0) {
+		/*
+		 * This fix is needed to overcome the timestamp filter putting
+		 * events in the future.
+		 */
+		sensorhub->future_timestamp_total_ns +=
+			*current_timestamp - now;
+		if (++sensorhub->future_timestamp_count ==
+				FUTURE_TS_ANALYTICS_COUNT_MAX) {
+			s64 avg = div_s64(sensorhub->future_timestamp_total_ns,
+					sensorhub->future_timestamp_count);
+			dev_warn_ratelimited(sensorhub->dev,
+					     "100 timestamps in the future, %lldns shaved on average\n",
+					     avg);
+			sensorhub->future_timestamp_count = 0;
+			sensorhub->future_timestamp_total_ns = 0;
+		}
 		out->timestamp = now;
-	else
+	} else {
 		out->timestamp = *current_timestamp;
+	}
 
 	out->flag = in->flags;
 	for (axis = 0; axis < 3; axis++)
 		out->vector[axis] = in->data[axis];
 
+	if (sensorhub->tight_timestamps)
+		cros_ec_sensor_ring_check_for_past_timestamp(sensorhub, out);
 	return true;
 }
 
 /*
  * cros_ec_sensor_ring_spread_add: Calculate proper timestamps then add to
- * ringbuffer.
+ *                                 ringbuffer.
+ *
+ * This is the new spreading code, assumes every sample's timestamp
+ * preceeds the sample. Run if tight_timestamps == true.
+ *
+ * Sometimes the EC receives only one interrupt (hence timestamp) for
+ * a batch of samples. Only the first sample will have the correct
+ * timestamp. So we must interpolate the other samples.
+ * We use the previous batch timestamp and our current batch timestamp
+ * as a way to calculate period, then spread the samples evenly.
+ *
+ * s0 int, 0ms
+ * s1 int, 10ms
+ * s2 int, 20ms
+ * 30ms point goes by, no interrupt, previous one is still asserted
+ * downloading s2 and s3
+ * s3 sample, 20ms (incorrect timestamp)
+ * s4 int, 40ms
+ *
+ * The batches are [(s0), (s1), (s2, s3), (s4)]. Since the 3rd batch
+ * has 2 samples in them, we adjust the timestamp of s3.
+ * s2 - s1 = 10ms, so s3 must be s2 + 10ms => 20ms. If s1 would have
+ * been part of a bigger batch things would have gotten a little
+ * more complicated.
+ *
+ * Note: we also assume another sensor sample doesn't break up a batch
+ * in 2 or more partitions. Example, there can't ever be a sync sensor
+ * in between S2 and S3. This simplifies the following code.
+ */
+static void
+cros_ec_sensor_ring_spread_add(struct cros_ec_sensorhub *sensorhub,
+			       unsigned long sensor_mask,
+			       struct cros_ec_sensors_ring_sample *last_out)
+{
+	struct cros_ec_sensors_ring_sample *batch_start, *next_batch_start;
+	int id;
+
+	for_each_set_bit(id, &sensor_mask, BITS_PER_LONG) {
+		for (batch_start = sensorhub->ring; batch_start < last_out;
+		     batch_start = next_batch_start) {
+			/*
+			 * For each batch (where all samples have the same
+			 * timestamp).
+			 */
+			int batch_len, sample_idx;
+			struct cros_ec_sensors_ring_sample *batch_end =
+				batch_start;
+			struct cros_ec_sensors_ring_sample *s;
+			s64 batch_timestamp = batch_start->timestamp;
+			s64 sample_period;
+
+			/*
+			 * Skip over batches that start with the sensor types
+			 * we're not looking at right now.
+			 */
+			if (batch_start->sensor_id != id) {
+				next_batch_start = batch_start + 1;
+				continue;
+			}
+
+			/*
+			 * Do not start a batch
+			 * from a flush, as it happens asynchronously to the
+			 * regular flow of events.
+			 */
+			if (batch_start->flag & MOTIONSENSE_SENSOR_FLAG_FLUSH) {
+				cros_sensorhub_send_sample(sensorhub,
+							   batch_start);
+				next_batch_start = batch_start + 1;
+				continue;
+			}
+
+			if (batch_start->timestamp <=
+			    sensorhub->last_batch_timestamp[id]) {
+				batch_timestamp =
+					sensorhub->last_batch_timestamp[id];
+				batch_len = sensorhub->last_batch_len[id];
+
+				sample_idx = batch_len;
+
+				sensorhub->last_batch_timestamp[id] =
+				  sensorhub->penultimate_batch_timestamp[id];
+				sensorhub->last_batch_len[id] =
+				  sensorhub->penultimate_batch_len[id];
+			} else {
+				/*
+				 * Push first sample in the batch to the,
+				 * kifo, it's guaranteed to be correct, the
+				 * rest will follow later on.
+				 */
+				sample_idx = 1;
+				batch_len = 1;
+				cros_sensorhub_send_sample(sensorhub,
+							   batch_start);
+				batch_start++;
+			}
+
+			/* Find all samples have the same timestamp. */
+			for (s = batch_start; s < last_out; s++) {
+				if (s->sensor_id != id)
+					/*
+					 * Skip over other sensor types that
+					 * are interleaved, don't count them.
+					 */
+					continue;
+				if (s->timestamp != batch_timestamp)
+					/* we discovered the next batch */
+					break;
+				if (s->flag & MOTIONSENSE_SENSOR_FLAG_FLUSH)
+					/* break on flush packets */
+					break;
+				batch_end = s;
+				batch_len++;
+			}
+
+			if (batch_len == 1)
+				goto done_with_this_batch;
+
+			/* Can we calculate period? */
+			if (sensorhub->last_batch_len[id] == 0) {
+				dev_warn(sensorhub->dev, "Sensor %d: lost %d samples when spreading\n",
+					 id, batch_len - 1);
+				goto done_with_this_batch;
+				/*
+				 * Note: we're dropping the rest of the samples
+				 * in this batch since we have no idea where
+				 * they're supposed to go without a period
+				 * calculation.
+				 */
+			}
+
+			sample_period = div_s64(batch_timestamp -
+					sensorhub->last_batch_timestamp[id],
+					sensorhub->last_batch_len[id]);
+			dev_dbg(sensorhub->dev,
+				"Adjusting %d samples, sensor %d last_batch @%lld (%d samples) batch_timestamp=%lld => period=%lld\n",
+				batch_len, id,
+				sensorhub->last_batch_timestamp[id],
+				sensorhub->last_batch_len[id],
+				batch_timestamp,
+				sample_period);
+
+			/*
+			 * Adjust timestamps of the samples then push them to
+			 * kfifo.
+			 */
+			for (s = batch_start; s <= batch_end; s++) {
+				if (s->sensor_id != id)
+					/*
+					 * Skip over other sensor types that
+					 * are interleaved, don't change them.
+					 */
+					continue;
+
+				s->timestamp = batch_timestamp +
+					sample_period * sample_idx;
+				sample_idx++;
+
+				cros_sensorhub_send_sample(sensorhub, s);
+			}
+
+done_with_this_batch:
+			sensorhub->penultimate_batch_timestamp[id] =
+				sensorhub->last_batch_timestamp[id];
+			sensorhub->penultimate_batch_len[id] =
+				sensorhub->last_batch_len[id];
+
+			sensorhub->last_batch_timestamp[id] = batch_timestamp;
+			sensorhub->last_batch_len[id] = batch_len;
+
+			next_batch_start = batch_end + 1;
+		}
+	}
+}
+
+/*
+ * cros_ec_sensor_ring_spread_add_legacy: Calculate proper timestamps then
+ * add to ringbuffer (legacy).
+ *
+ * Note: This assumes we're running old firmware, where every sample's timestamp
+ * is after the sample. Run if tight_timestamps == false.
  *
  * If there is a sample with a proper timestamp
  *
@@ -214,11 +689,12 @@ cros_ec_sensor_ring_process_event(struct cros_ec_sensorhub *sensorhub,
  *
  * We know have [TS1+1/3, TS1+2/3, current timestamp]
  */
-static void cros_ec_sensor_ring_spread_add(struct cros_ec_sensorhub *sensorhub,
-					   unsigned long sensor_mask,
-					   s64 current_timestamp,
-					   struct cros_ec_sensors_ring_sample
-					   *last_out)
+static void
+cros_ec_sensor_ring_spread_add_legacy(struct cros_ec_sensorhub *sensorhub,
+				      unsigned long sensor_mask,
+				      s64 current_timestamp,
+				      struct cros_ec_sensors_ring_sample
+				      *last_out)
 {
 	struct cros_ec_sensors_ring_sample *out;
 	int i;
@@ -400,7 +876,8 @@ static void cros_ec_sensorhub_ring_handler(struct cros_ec_sensorhub *sensorhub)
 	 * is slow to respond to the IRQ, the EC may have added new samples.
 	 * Use the FIFO info timestamp as last timestamp then.
 	 */
-	if ((last_out - 1)->timestamp == current_timestamp)
+	if (!sensorhub->tight_timestamps &&
+	    (last_out - 1)->timestamp == current_timestamp)
 		current_timestamp = fifo_timestamp;
 
 	/* Warn on lost samples. */
@@ -414,6 +891,7 @@ static void cros_ec_sensorhub_ring_handler(struct cros_ec_sensorhub *sensorhub)
 				dev_warn_ratelimited(sensorhub->dev,
 						     "Sensor %d: lost: %d out of %d\n",
 						     i, lost, total_lost);
+				sensorhub->last_batch_len[i] = 0;
 			}
 		}
 	}
@@ -422,8 +900,13 @@ static void cros_ec_sensorhub_ring_handler(struct cros_ec_sensorhub *sensorhub)
 	 * Spread samples in case of batching, then add them to the
 	 * ringbuffer.
 	 */
-	cros_ec_sensor_ring_spread_add(sensorhub, sensor_mask,
-				       current_timestamp, last_out);
+	if (sensorhub->tight_timestamps)
+		cros_ec_sensor_ring_spread_add(sensorhub, sensor_mask,
+					       last_out);
+	else
+		cros_ec_sensor_ring_spread_add_legacy(sensorhub, sensor_mask,
+						      current_timestamp,
+						      last_out);
 
 ring_handler_end:
 	sensorhub->fifo_timestamp[CROS_EC_SENSOR_LAST_TS] = current_timestamp;
@@ -500,6 +983,9 @@ int cros_ec_sensorhub_ring_add(struct cros_ec_sensorhub *sensorhub)
 	sensorhub->fifo_timestamp[CROS_EC_SENSOR_LAST_TS] =
 		cros_ec_get_time_ns();
 
+	sensorhub->tight_timestamps = cros_ec_check_features(
+			ec, EC_FEATURE_MOTION_SENSE_TIGHT_TIMESTAMPS);
+
 	/* Register the notifier that will act as a top half interrupt. */
 	sensorhub->notifier.notifier_call = cros_ec_sensorhub_event;
 	ret = blocking_notifier_chain_register(&ec->ec_dev->event_notifier,
diff --git a/include/linux/platform_data/cros_ec_sensorhub.h b/include/linux/platform_data/cros_ec_sensorhub.h
index cb849a2da4f60..180b36adc3493 100644
--- a/include/linux/platform_data/cros_ec_sensorhub.h
+++ b/include/linux/platform_data/cros_ec_sensorhub.h
@@ -68,7 +68,44 @@ struct cros_ec_sensors_ring_sample {
 	s64 timestamp;
 } __packed;
 
+/* State used for cros_ec_ring_fix_overflow */
+struct cros_ec_sensors_ec_overflow_state {
+	s64 offset;
+	s64 last;
+};
+
+/* Length of the filter, how long to remember entries for */
+#define CROS_EC_SENSORHUB_TS_HISTORY_SIZE 64
+
 /**
+ * struct cros_ec_sensors_ts_filter_state - Timestamp filetr state.
+ *
+ * @x_offset: x is EC interrupt time. x_offset its last value.
+ * @y_offset: y is the difference between AP and EC time, y_offset its last
+ *            value.
+ * @x_history: The past history of x, relative to x_offset.
+ * @y_history: The past history of y, relative to y_offset.
+ * @m_history: rate between y and x.
+ * @history_len: Amount of valid historic data in the arrays.
+ * @temp_buf: Temporary buffer used when updating the filter.
+ * @median_m: median value of m_history
+ * @median_error: final error to apply to AP interrupt timestamp to get the
+ *                "true timestamp" the event occurred.
+ */
+struct cros_ec_sensors_ts_filter_state {
+	s64 x_offset, y_offset;
+	s64 x_history[CROS_EC_SENSORHUB_TS_HISTORY_SIZE];
+	s64 y_history[CROS_EC_SENSORHUB_TS_HISTORY_SIZE];
+	s64 m_history[CROS_EC_SENSORHUB_TS_HISTORY_SIZE];
+	int history_len;
+
+	s64 temp_buf[CROS_EC_SENSORHUB_TS_HISTORY_SIZE];
+
+	s64 median_m;
+	s64 median_error;
+};
+
+/*
  * struct cros_ec_sensorhub - Sensor Hub device data.
  *
  * @dev: Device object, mostly used for logging.
@@ -79,10 +116,32 @@ struct cros_ec_sensors_ring_sample {
  * @cmd_lock : Lock for sending msg.
  * @notifier: Notifier to kick the FIFO interrupt.
  * @ring: Preprocessed ring to store events.
- * @fifo_timestamp: array for event timestamp and spreading.
- * @fifo_info: copy of FIFO information coming from the EC.
- * @fifo_size: size of the ring.
- * @push_data: array of callback to send datums to iio sensor object.
+ * @fifo_timestamp: Array for event timestamp and spreading.
+ * @fifo_info: Copy of FIFO information coming from the EC.
+ * @fifo_size: Size of the ring.
+ * @penultimate_batch_timestamp: Array of last but one batch timestamps.
+ *				 Used for timestamp spreading calculations
+ *				 when a batch shows up.
+ * @penultimate_batch_len: Array of last but one batch length.
+ * @last_batch_timestamp: Last batch timestamp array.
+ * @last_batch_len: Last batch length array.
+ * @newest_sensor_event: Last sensor timestamp.
+ * @overflow_a: For handling timestamp overflow for a time (sensor events)
+ * @overflow_b: For handling timestamp overflow for b time (ec interrupts)
+ * @filter: Medium fileter structure.
+ * @tight_timestamps: Set to truen when EC support tight timestamping:
+ *		      The timestamps reported from the EC have low jitter.
+ *		      Timestamps also come before every sample. Set either
+ *		      by feature bits coming from the EC or userspace.
+ * @future_timestamp_count: Statistics used to compute shaved time.
+ *			    This occurs when timestamp interpolation from EC
+ *			    time to AP time accidentally puts timestamps in
+ *			    the future. These timestamps are clamped to
+ *			    `now` and these count/total_ns maintain the
+ *			    statistics for how much time was removed in a
+ *			    given period.
+ * @future_timestamp_total_ns: Total amount of time shaved.
+ * @push_data: Array of callback to send datums to iio sensor object.
  */
 struct cros_ec_sensorhub {
 	struct device *dev;
@@ -101,6 +160,22 @@ struct cros_ec_sensorhub {
 	struct cros_ec_fifo_info fifo_info;
 	int fifo_size;
 
+	s64 penultimate_batch_timestamp[CROS_EC_SENSOR_MAX];
+	int penultimate_batch_len[CROS_EC_SENSOR_MAX];
+	s64 last_batch_timestamp[CROS_EC_SENSOR_MAX];
+	int last_batch_len[CROS_EC_SENSOR_MAX];
+	s64 newest_sensor_event[CROS_EC_SENSOR_MAX];
+
+	struct cros_ec_sensors_ec_overflow_state overflow_a;
+	struct cros_ec_sensors_ec_overflow_state overflow_b;
+
+	struct cros_ec_sensors_ts_filter_state filter;
+
+	int tight_timestamps;
+
+	s32 future_timestamp_count;
+	s64 future_timestamp_total_ns;
+
 	struct cros_ec_sensorhub_sensor_push_data
 		push_data[CROS_EC_SENSOR_PDEV_MAX];
 };
-- 
2.25.1.696.g5e7596f4ac-goog


^ permalink raw reply	[flat|nested] 15+ messages in thread

* [PATCH v6 04/11] iio: cros_ec: Move function description to .c file
  2020-03-24 20:27 [PATCH v6 00/11] Cros EC sensor hub FIFO support Gwendal Grignou
                   ` (2 preceding siblings ...)
  2020-03-24 20:27 ` [PATCH v6 03/11] platform: chrome: sensorhub: Add median filter Gwendal Grignou
@ 2020-03-24 20:27 ` Gwendal Grignou
  2020-03-24 20:27 ` [PATCH v6 05/11] iio: expose iio_device_set_clock Gwendal Grignou
                   ` (7 subsequent siblings)
  11 siblings, 0 replies; 15+ messages in thread
From: Gwendal Grignou @ 2020-03-24 20:27 UTC (permalink / raw)
  To: bleung, enric.balletbo, Jonathan.Cameron
  Cc: linux-iio, linux-kernel, Gwendal Grignou

To prevent comment rot, move function description to
cros_ec_sensors_core.c.

Acked-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Acked-by: Enric Balletbo i Serra <enric.balletbo@collabora.com>
Signed-off-by: Gwendal Grignou <gwendal@chromium.org>
---
Changes in v6:
- No changes.
Changes in v5:
  Added ack.
No changes in v4.
Changes in v3:
  fix spelling.
New in v2.

 .../cros_ec_sensors/cros_ec_sensors_core.c    | 69 ++++++++++++++++
 .../linux/iio/common/cros_ec_sensors_core.h   | 80 -------------------
 2 files changed, 69 insertions(+), 80 deletions(-)

diff --git a/drivers/iio/common/cros_ec_sensors/cros_ec_sensors_core.c b/drivers/iio/common/cros_ec_sensors/cros_ec_sensors_core.c
index d3a3626c7cd83..f3c000448b90e 100644
--- a/drivers/iio/common/cros_ec_sensors/cros_ec_sensors_core.c
+++ b/drivers/iio/common/cros_ec_sensors/cros_ec_sensors_core.c
@@ -82,6 +82,14 @@ static void get_default_min_max_freq(enum motionsensor_type type,
 	}
 }
 
+/**
+ * cros_ec_sensors_core_init() - basic initialization of the core structure
+ * @pdev:		platform device created for the sensors
+ * @indio_dev:		iio device structure of the device
+ * @physical_device:	true if the device refers to a physical device
+ *
+ * Return: 0 on success, -errno on failure.
+ */
 int cros_ec_sensors_core_init(struct platform_device *pdev,
 			      struct iio_dev *indio_dev,
 			      bool physical_device)
@@ -159,6 +167,16 @@ int cros_ec_sensors_core_init(struct platform_device *pdev,
 }
 EXPORT_SYMBOL_GPL(cros_ec_sensors_core_init);
 
+/**
+ * cros_ec_motion_send_host_cmd() - send motion sense host command
+ * @state:		pointer to state information for device
+ * @opt_length:	optional length to reduce the response size, useful on the data
+ *		path. Otherwise, the maximal allowed response size is used
+ *
+ * When called, the sub-command is assumed to be set in param->cmd.
+ *
+ * Return: 0 on success, -errno on failure.
+ */
 int cros_ec_motion_send_host_cmd(struct cros_ec_sensors_core_state *state,
 				 u16 opt_length)
 {
@@ -421,6 +439,14 @@ int cros_ec_sensors_read_lpc(struct iio_dev *indio_dev,
 }
 EXPORT_SYMBOL_GPL(cros_ec_sensors_read_lpc);
 
+/**
+ * cros_ec_sensors_read_cmd() - retrieve data using the EC command protocol
+ * @indio_dev:	pointer to IIO device
+ * @scan_mask:	bitmap of the sensor indices to scan
+ * @data:	location to store data
+ *
+ * Return: 0 on success, -errno on failure.
+ */
 int cros_ec_sensors_read_cmd(struct iio_dev *indio_dev,
 			     unsigned long scan_mask, s16 *data)
 {
@@ -445,6 +471,18 @@ int cros_ec_sensors_read_cmd(struct iio_dev *indio_dev,
 }
 EXPORT_SYMBOL_GPL(cros_ec_sensors_read_cmd);
 
+/**
+ * cros_ec_sensors_capture() - the trigger handler function
+ * @irq:	the interrupt number.
+ * @p:		a pointer to the poll function.
+ *
+ * On a trigger event occurring, if the pollfunc is attached then this
+ * handler is called as a threaded interrupt (and hence may sleep). It
+ * is responsible for grabbing data from the device and pushing it into
+ * the associated buffer.
+ *
+ * Return: IRQ_HANDLED
+ */
 irqreturn_t cros_ec_sensors_capture(int irq, void *p)
 {
 	struct iio_poll_func *pf = p;
@@ -480,6 +518,16 @@ irqreturn_t cros_ec_sensors_capture(int irq, void *p)
 }
 EXPORT_SYMBOL_GPL(cros_ec_sensors_capture);
 
+/**
+ * cros_ec_sensors_core_read() - function to request a value from the sensor
+ * @st:		pointer to state information for device
+ * @chan:	channel specification structure table
+ * @val:	will contain one element making up the returned value
+ * @val2:	will contain another element making up the returned value
+ * @mask:	specifies which values to be requested
+ *
+ * Return:	the type of value returned by the device
+ */
 int cros_ec_sensors_core_read(struct cros_ec_sensors_core_state *st,
 			  struct iio_chan_spec const *chan,
 			  int *val, int *val2, long mask)
@@ -520,6 +568,17 @@ int cros_ec_sensors_core_read(struct cros_ec_sensors_core_state *st,
 }
 EXPORT_SYMBOL_GPL(cros_ec_sensors_core_read);
 
+/**
+ * cros_ec_sensors_core_read_avail() - get available values
+ * @indio_dev:		pointer to state information for device
+ * @chan:	channel specification structure table
+ * @vals:	list of available values
+ * @type:	type of data returned
+ * @length:	number of data returned in the array
+ * @mask:	specifies which values to be requested
+ *
+ * Return:	an error code, IIO_AVAIL_RANGE or IIO_AVAIL_LIST
+ */
 int cros_ec_sensors_core_read_avail(struct iio_dev *indio_dev,
 				    struct iio_chan_spec const *chan,
 				    const int **vals,
@@ -541,6 +600,16 @@ int cros_ec_sensors_core_read_avail(struct iio_dev *indio_dev,
 }
 EXPORT_SYMBOL_GPL(cros_ec_sensors_core_read_avail);
 
+/**
+ * cros_ec_sensors_core_write() - function to write a value to the sensor
+ * @st:		pointer to state information for device
+ * @chan:	channel specification structure table
+ * @val:	first part of value to write
+ * @val2:	second part of value to write
+ * @mask:	specifies which values to write
+ *
+ * Return:	the type of value returned by the device
+ */
 int cros_ec_sensors_core_write(struct cros_ec_sensors_core_state *st,
 			       struct iio_chan_spec const *chan,
 			       int val, int val2, long mask)
diff --git a/include/linux/iio/common/cros_ec_sensors_core.h b/include/linux/iio/common/cros_ec_sensors_core.h
index bb331e6356a9c..0af918978f975 100644
--- a/include/linux/iio/common/cros_ec_sensors_core.h
+++ b/include/linux/iio/common/cros_ec_sensors_core.h
@@ -79,95 +79,25 @@ struct cros_ec_sensors_core_state {
 	int frequencies[3];
 };
 
-/**
- * cros_ec_sensors_read_lpc() - retrieve data from EC shared memory
- * @indio_dev:	pointer to IIO device
- * @scan_mask:	bitmap of the sensor indices to scan
- * @data:	location to store data
- *
- * This is the safe function for reading the EC data. It guarantees that the
- * data sampled was not modified by the EC while being read.
- *
- * Return: 0 on success, -errno on failure.
- */
 int cros_ec_sensors_read_lpc(struct iio_dev *indio_dev, unsigned long scan_mask,
 			     s16 *data);
 
-/**
- * cros_ec_sensors_read_cmd() - retrieve data using the EC command protocol
- * @indio_dev:	pointer to IIO device
- * @scan_mask:	bitmap of the sensor indices to scan
- * @data:	location to store data
- *
- * Return: 0 on success, -errno on failure.
- */
 int cros_ec_sensors_read_cmd(struct iio_dev *indio_dev, unsigned long scan_mask,
 			     s16 *data);
 
 struct platform_device;
-/**
- * cros_ec_sensors_core_init() - basic initialization of the core structure
- * @pdev:		platform device created for the sensors
- * @indio_dev:		iio device structure of the device
- * @physical_device:	true if the device refers to a physical device
- *
- * Return: 0 on success, -errno on failure.
- */
 int cros_ec_sensors_core_init(struct platform_device *pdev,
 			      struct iio_dev *indio_dev, bool physical_device);
 
-/**
- * cros_ec_sensors_capture() - the trigger handler function
- * @irq:	the interrupt number.
- * @p:		a pointer to the poll function.
- *
- * On a trigger event occurring, if the pollfunc is attached then this
- * handler is called as a threaded interrupt (and hence may sleep). It
- * is responsible for grabbing data from the device and pushing it into
- * the associated buffer.
- *
- * Return: IRQ_HANDLED
- */
 irqreturn_t cros_ec_sensors_capture(int irq, void *p);
 
-/**
- * cros_ec_motion_send_host_cmd() - send motion sense host command
- * @st:		pointer to state information for device
- * @opt_length:	optional length to reduce the response size, useful on the data
- *		path. Otherwise, the maximal allowed response size is used
- *
- * When called, the sub-command is assumed to be set in param->cmd.
- *
- * Return: 0 on success, -errno on failure.
- */
 int cros_ec_motion_send_host_cmd(struct cros_ec_sensors_core_state *st,
 				 u16 opt_length);
 
-/**
- * cros_ec_sensors_core_read() - function to request a value from the sensor
- * @st:		pointer to state information for device
- * @chan:	channel specification structure table
- * @val:	will contain one element making up the returned value
- * @val2:	will contain another element making up the returned value
- * @mask:	specifies which values to be requested
- *
- * Return:	the type of value returned by the device
- */
 int cros_ec_sensors_core_read(struct cros_ec_sensors_core_state *st,
 			      struct iio_chan_spec const *chan,
 			      int *val, int *val2, long mask);
 
-/**
- * cros_ec_sensors_core_read_avail() - get available values
- * @indio_dev:		pointer to state information for device
- * @chan:	channel specification structure table
- * @vals:	list of available values
- * @type:	type of data returned
- * @length:	number of data returned in the array
- * @mask:	specifies which values to be requested
- *
- * Return:	an error code, IIO_AVAIL_RANGE or IIO_AVAIL_LIST
- */
 int cros_ec_sensors_core_read_avail(struct iio_dev *indio_dev,
 				    struct iio_chan_spec const *chan,
 				    const int **vals,
@@ -175,16 +105,6 @@ int cros_ec_sensors_core_read_avail(struct iio_dev *indio_dev,
 				    int *length,
 				    long mask);
 
-/**
- * cros_ec_sensors_core_write() - function to write a value to the sensor
- * @st:		pointer to state information for device
- * @chan:	channel specification structure table
- * @val:	first part of value to write
- * @val2:	second part of value to write
- * @mask:	specifies which values to write
- *
- * Return:	the type of value returned by the device
- */
 int cros_ec_sensors_core_write(struct cros_ec_sensors_core_state *st,
 			       struct iio_chan_spec const *chan,
 			       int val, int val2, long mask);
-- 
2.25.1.696.g5e7596f4ac-goog


^ permalink raw reply	[flat|nested] 15+ messages in thread

* [PATCH v6 05/11] iio: expose iio_device_set_clock
  2020-03-24 20:27 [PATCH v6 00/11] Cros EC sensor hub FIFO support Gwendal Grignou
                   ` (3 preceding siblings ...)
  2020-03-24 20:27 ` [PATCH v6 04/11] iio: cros_ec: Move function description to .c file Gwendal Grignou
@ 2020-03-24 20:27 ` Gwendal Grignou
  2020-03-24 20:27 ` [PATCH v6 06/11] iio: cros_ec: Register to cros_ec_sensorhub when EC supports FIFO Gwendal Grignou
                   ` (6 subsequent siblings)
  11 siblings, 0 replies; 15+ messages in thread
From: Gwendal Grignou @ 2020-03-24 20:27 UTC (permalink / raw)
  To: bleung, enric.balletbo, Jonathan.Cameron
  Cc: linux-iio, linux-kernel, Gwendal Grignou

Some IIO devices may want to override the default (realtime) to another
clock source by default.
It can beneficial when timestamps coming from the hardware or underlying
drivers are already in that format.
It can always be overridden by attribute current_timestamp_clock.

Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Gwendal Grignou <gwendal@chromium.org>
---
Changes in v6:
- No changes.
Changes in v5:
- New in v5.

 drivers/iio/industrialio-core.c | 8 +++++++-
 include/linux/iio/iio.h         | 2 ++
 2 files changed, 9 insertions(+), 1 deletion(-)

diff --git a/drivers/iio/industrialio-core.c b/drivers/iio/industrialio-core.c
index 65ff0d0670188..26e963483bab0 100644
--- a/drivers/iio/industrialio-core.c
+++ b/drivers/iio/industrialio-core.c
@@ -189,7 +189,12 @@ ssize_t iio_read_const_attr(struct device *dev,
 }
 EXPORT_SYMBOL(iio_read_const_attr);
 
-static int iio_device_set_clock(struct iio_dev *indio_dev, clockid_t clock_id)
+/**
+ * iio_device_set_clock() - Set current timestamping clock for the device
+ * @indio_dev: IIO device structure containing the device
+ * @clock_id: timestamping clock posix identifier to set.
+ */
+int iio_device_set_clock(struct iio_dev *indio_dev, clockid_t clock_id)
 {
 	int ret;
 	const struct iio_event_interface *ev_int = indio_dev->event_interface;
@@ -207,6 +212,7 @@ static int iio_device_set_clock(struct iio_dev *indio_dev, clockid_t clock_id)
 
 	return 0;
 }
+EXPORT_SYMBOL(iio_device_set_clock);
 
 /**
  * iio_get_time_ns() - utility function to get a time stamp for events etc
diff --git a/include/linux/iio/iio.h b/include/linux/iio/iio.h
index 862ce0019eba5..b18f34a8901f3 100644
--- a/include/linux/iio/iio.h
+++ b/include/linux/iio/iio.h
@@ -627,6 +627,8 @@ static inline clockid_t iio_device_get_clock(const struct iio_dev *indio_dev)
 	return indio_dev->clock_id;
 }
 
+int iio_device_set_clock(struct iio_dev *indio_dev, clockid_t clock_id);
+
 /**
  * dev_to_iio_dev() - Get IIO device struct from a device struct
  * @dev: 		The device embedded in the IIO device
-- 
2.25.1.696.g5e7596f4ac-goog


^ permalink raw reply	[flat|nested] 15+ messages in thread

* [PATCH v6 06/11] iio: cros_ec: Register to cros_ec_sensorhub when EC supports FIFO
  2020-03-24 20:27 [PATCH v6 00/11] Cros EC sensor hub FIFO support Gwendal Grignou
                   ` (4 preceding siblings ...)
  2020-03-24 20:27 ` [PATCH v6 05/11] iio: expose iio_device_set_clock Gwendal Grignou
@ 2020-03-24 20:27 ` Gwendal Grignou
  2020-03-24 20:27 ` [PATCH v6 07/11] iio: cros_ec: Remove pm function Gwendal Grignou
                   ` (5 subsequent siblings)
  11 siblings, 0 replies; 15+ messages in thread
From: Gwendal Grignou @ 2020-03-24 20:27 UTC (permalink / raw)
  To: bleung, enric.balletbo, Jonathan.Cameron
  Cc: linux-iio, linux-kernel, Gwendal Grignou

When EC supports FIFO, each IIO device registers a callback, to put
samples in the buffer when they arrives from the FIFO.

When no FIFO, the user space app needs to call trigger_new, or better
register a high precision timer.

Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Gwendal Grignou <gwendal@chromium.org>
---
Changes in v6:
- Revert code from v2 that allow trigger in FIFO mode. It was causing
  a crash when events would flow from hardware FIFO in but no triggers
  were setup.
  Creating a triggered buffers and a hardware interrupt trigger from
  the sensorhub and having to connect the trigger to sensor before use
  was not practical.
Changes in v5:
- Revert modes setting that were removed by mistake
- Remove unnecessary check when receving events from callback
- Set clock_id to boottime by default, as it is what sensorhub_ring is
  using.
- Update commit messages reference to time domain: trigger and hub
  generated events are always in the same time domain.
Changes in v4:
- Fix a logic error when the sensor is not "physical", for instance lig
  angle: core_init() would return !0 even if there was no error.
- Check patch with --strict option
    Use sizeof(*obj) instead of sizeof(struct ...obj)
    Alignement
Change in v3:
- Remove double line
- Fix indentation
- Add code to support iio clock_id setting. Optimized for
  CLOCK_BOOTTIME.
Change in v2 from "Use triggered buffer only when EC does not support
FIFO":
- Keep trigger all the time.
- Add  devm_add_action to cleanup callback registration.
- EC that "reports" legacy sensors do not have FIFO.
- Use iiio_is_buffer_enabled instead of checking the scan_mask
  before sending samples to buffer.
- Add empty lines for visibility.

 drivers/iio/accel/cros_ec_accel_legacy.c      |   8 +-
 .../cros_ec_sensors/cros_ec_lid_angle.c       |   2 +-
 .../common/cros_ec_sensors/cros_ec_sensors.c  |   9 +-
 .../cros_ec_sensors/cros_ec_sensors_core.c    | 101 +++++++++++++++++-
 drivers/iio/light/cros_ec_light_prox.c        |   9 +-
 drivers/iio/pressure/cros_ec_baro.c           |   9 +-
 .../linux/iio/common/cros_ec_sensors_core.h   |  10 +-
 7 files changed, 119 insertions(+), 29 deletions(-)

diff --git a/drivers/iio/accel/cros_ec_accel_legacy.c b/drivers/iio/accel/cros_ec_accel_legacy.c
index 68e847c6255e3..2532b9ad33842 100644
--- a/drivers/iio/accel/cros_ec_accel_legacy.c
+++ b/drivers/iio/accel/cros_ec_accel_legacy.c
@@ -170,7 +170,8 @@ static int cros_ec_accel_legacy_probe(struct platform_device *pdev)
 	if (!indio_dev)
 		return -ENOMEM;
 
-	ret = cros_ec_sensors_core_init(pdev, indio_dev, true);
+	ret = cros_ec_sensors_core_init(pdev, indio_dev, true,
+					cros_ec_sensors_capture, NULL);
 	if (ret)
 		return ret;
 
@@ -190,11 +191,6 @@ static int cros_ec_accel_legacy_probe(struct platform_device *pdev)
 		state->sign[CROS_EC_SENSOR_Z] = -1;
 	}
 
-	ret = devm_iio_triggered_buffer_setup(dev, indio_dev, NULL,
-			cros_ec_sensors_capture, NULL);
-	if (ret)
-		return ret;
-
 	return devm_iio_device_register(dev, indio_dev);
 }
 
diff --git a/drivers/iio/common/cros_ec_sensors/cros_ec_lid_angle.c b/drivers/iio/common/cros_ec_sensors/cros_ec_lid_angle.c
index 1dcc2a16ab2dd..e30a59fcf0f95 100644
--- a/drivers/iio/common/cros_ec_sensors/cros_ec_lid_angle.c
+++ b/drivers/iio/common/cros_ec_sensors/cros_ec_lid_angle.c
@@ -97,7 +97,7 @@ static int cros_ec_lid_angle_probe(struct platform_device *pdev)
 	if (!indio_dev)
 		return -ENOMEM;
 
-	ret = cros_ec_sensors_core_init(pdev, indio_dev, false);
+	ret = cros_ec_sensors_core_init(pdev, indio_dev, false, NULL, NULL);
 	if (ret)
 		return ret;
 
diff --git a/drivers/iio/common/cros_ec_sensors/cros_ec_sensors.c b/drivers/iio/common/cros_ec_sensors/cros_ec_sensors.c
index 576e45faafaff..711134d67ddee 100644
--- a/drivers/iio/common/cros_ec_sensors/cros_ec_sensors.c
+++ b/drivers/iio/common/cros_ec_sensors/cros_ec_sensors.c
@@ -230,7 +230,9 @@ static int cros_ec_sensors_probe(struct platform_device *pdev)
 	if (!indio_dev)
 		return -ENOMEM;
 
-	ret = cros_ec_sensors_core_init(pdev, indio_dev, true);
+	ret = cros_ec_sensors_core_init(pdev, indio_dev, true,
+					cros_ec_sensors_capture,
+					cros_ec_sensors_push_data);
 	if (ret)
 		return ret;
 
@@ -292,11 +294,6 @@ static int cros_ec_sensors_probe(struct platform_device *pdev)
 	else
 		state->core.read_ec_sensors_data = cros_ec_sensors_read_cmd;
 
-	ret = devm_iio_triggered_buffer_setup(dev, indio_dev, NULL,
-			cros_ec_sensors_capture, NULL);
-	if (ret)
-		return ret;
-
 	return devm_iio_device_register(dev, indio_dev);
 }
 
diff --git a/drivers/iio/common/cros_ec_sensors/cros_ec_sensors_core.c b/drivers/iio/common/cros_ec_sensors/cros_ec_sensors_core.c
index f3c000448b90e..01513cb933653 100644
--- a/drivers/iio/common/cros_ec_sensors/cros_ec_sensors_core.c
+++ b/drivers/iio/common/cros_ec_sensors/cros_ec_sensors_core.c
@@ -12,6 +12,7 @@
 #include <linux/iio/iio.h>
 #include <linux/iio/kfifo_buf.h>
 #include <linux/iio/trigger_consumer.h>
+#include <linux/iio/triggered_buffer.h>
 #include <linux/kernel.h>
 #include <linux/module.h>
 #include <linux/slab.h>
@@ -82,17 +83,71 @@ static void get_default_min_max_freq(enum motionsensor_type type,
 	}
 }
 
+int cros_ec_sensors_push_data(struct iio_dev *indio_dev,
+			      s16 *data,
+			      s64 timestamp)
+{
+	struct cros_ec_sensors_core_state *st = iio_priv(indio_dev);
+	s16 *out;
+	s64 delta;
+	unsigned int i;
+
+	/*
+	 * Ignore samples if the buffer is not set: it is needed if the ODR is
+	 * set but the buffer is not enabled yet.
+	 */
+	if (!iio_buffer_enabled(indio_dev))
+		return 0;
+
+	out = (s16 *)st->samples;
+	for_each_set_bit(i,
+			 indio_dev->active_scan_mask,
+			 indio_dev->masklength) {
+		*out = data[i];
+		out++;
+	}
+
+	if (iio_device_get_clock(indio_dev) != CLOCK_BOOTTIME)
+		delta = iio_get_time_ns(indio_dev) - cros_ec_get_time_ns();
+	else
+		delta = 0;
+
+	iio_push_to_buffers_with_timestamp(indio_dev, st->samples,
+					   timestamp + delta);
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(cros_ec_sensors_push_data);
+
+static void cros_ec_sensors_core_clean(void *arg)
+{
+	struct platform_device *pdev = (struct platform_device *)arg;
+	struct cros_ec_sensorhub *sensor_hub =
+		dev_get_drvdata(pdev->dev.parent);
+	struct iio_dev *indio_dev = platform_get_drvdata(pdev);
+	struct cros_ec_sensors_core_state *st = iio_priv(indio_dev);
+	u8 sensor_num = st->param.info.sensor_num;
+
+	cros_ec_sensorhub_unregister_push_data(sensor_hub, sensor_num);
+}
+
 /**
  * cros_ec_sensors_core_init() - basic initialization of the core structure
  * @pdev:		platform device created for the sensors
  * @indio_dev:		iio device structure of the device
  * @physical_device:	true if the device refers to a physical device
+ * @trigger_capture:    function pointer to call buffer is triggered,
+ *    for backward compatibility.
+ * @push_data:          function to call when cros_ec_sensorhub receives
+ *    a sample for that sensor.
  *
  * Return: 0 on success, -errno on failure.
  */
 int cros_ec_sensors_core_init(struct platform_device *pdev,
 			      struct iio_dev *indio_dev,
-			      bool physical_device)
+			      bool physical_device,
+			      cros_ec_sensors_capture_t trigger_capture,
+			      cros_ec_sensorhub_push_data_cb_t push_data)
 {
 	struct device *dev = &pdev->dev;
 	struct cros_ec_sensors_core_state *state = iio_priv(indio_dev);
@@ -131,8 +186,6 @@ int cros_ec_sensors_core_init(struct platform_device *pdev,
 	indio_dev->name = pdev->name;
 
 	if (physical_device) {
-		indio_dev->modes = INDIO_DIRECT_MODE;
-
 		state->param.cmd = MOTIONSENSE_CMD_INFO;
 		state->param.info.sensor_num = sensor_platform->sensor_num;
 		ret = cros_ec_motion_send_host_cmd(state, 0);
@@ -161,6 +214,48 @@ int cros_ec_sensors_core_init(struct platform_device *pdev,
 			state->frequencies[2] =
 			    state->resp->info_3.max_frequency;
 		}
+
+		if (cros_ec_check_features(ec, EC_FEATURE_MOTION_SENSE_FIFO)) {
+			/*
+			 * Create a software buffer, feed by the EC FIFO.
+			 * We can not use trigger here, as events are generated
+			 * as soon as sample_frequency is set.
+			 */
+			struct iio_buffer *buffer;
+
+			buffer = devm_iio_kfifo_allocate(dev);
+			if (!buffer)
+				return -ENOMEM;
+
+			iio_device_attach_buffer(indio_dev, buffer);
+			indio_dev->modes = INDIO_BUFFER_SOFTWARE;
+
+			ret = cros_ec_sensorhub_register_push_data(
+					sensor_hub, sensor_platform->sensor_num,
+					indio_dev, push_data);
+			if (ret)
+				return ret;
+
+			ret = devm_add_action_or_reset(
+					dev, cros_ec_sensors_core_clean, pdev);
+			if (ret)
+				return ret;
+
+			/* Timestamp coming from FIFO are in ns since boot. */
+			ret = iio_device_set_clock(indio_dev, CLOCK_BOOTTIME);
+			if (ret)
+				return ret;
+		} else {
+			/*
+			 * The only way to get samples in buffer is to set a
+			 * software tigger (systrig, hrtimer).
+			 */
+			ret = devm_iio_triggered_buffer_setup(
+					dev, indio_dev, NULL, trigger_capture,
+					NULL);
+			if (ret)
+				return ret;
+		}
 	}
 
 	return 0;
diff --git a/drivers/iio/light/cros_ec_light_prox.c b/drivers/iio/light/cros_ec_light_prox.c
index 7a838e2956f40..03c951ff4a3c3 100644
--- a/drivers/iio/light/cros_ec_light_prox.c
+++ b/drivers/iio/light/cros_ec_light_prox.c
@@ -177,7 +177,9 @@ static int cros_ec_light_prox_probe(struct platform_device *pdev)
 	if (!indio_dev)
 		return -ENOMEM;
 
-	ret = cros_ec_sensors_core_init(pdev, indio_dev, true);
+	ret = cros_ec_sensors_core_init(pdev, indio_dev, true,
+					cros_ec_sensors_capture,
+					cros_ec_sensors_push_data);
 	if (ret)
 		return ret;
 
@@ -236,11 +238,6 @@ static int cros_ec_light_prox_probe(struct platform_device *pdev)
 
 	state->core.read_ec_sensors_data = cros_ec_sensors_read_cmd;
 
-	ret = devm_iio_triggered_buffer_setup(dev, indio_dev, NULL,
-					      cros_ec_sensors_capture, NULL);
-	if (ret)
-		return ret;
-
 	return devm_iio_device_register(dev, indio_dev);
 }
 
diff --git a/drivers/iio/pressure/cros_ec_baro.c b/drivers/iio/pressure/cros_ec_baro.c
index b521bebd551c7..6add499f11aa6 100644
--- a/drivers/iio/pressure/cros_ec_baro.c
+++ b/drivers/iio/pressure/cros_ec_baro.c
@@ -134,7 +134,9 @@ static int cros_ec_baro_probe(struct platform_device *pdev)
 	if (!indio_dev)
 		return -ENOMEM;
 
-	ret = cros_ec_sensors_core_init(pdev, indio_dev, true);
+	ret = cros_ec_sensors_core_init(pdev, indio_dev, true,
+					cros_ec_sensors_capture,
+					cros_ec_sensors_push_data);
 	if (ret)
 		return ret;
 
@@ -182,11 +184,6 @@ static int cros_ec_baro_probe(struct platform_device *pdev)
 
 	state->core.read_ec_sensors_data = cros_ec_sensors_read_cmd;
 
-	ret = devm_iio_triggered_buffer_setup(dev, indio_dev, NULL,
-					      cros_ec_sensors_capture, NULL);
-	if (ret)
-		return ret;
-
 	return devm_iio_device_register(dev, indio_dev);
 }
 
diff --git a/include/linux/iio/common/cros_ec_sensors_core.h b/include/linux/iio/common/cros_ec_sensors_core.h
index 0af918978f975..b8f573ca9dcc9 100644
--- a/include/linux/iio/common/cros_ec_sensors_core.h
+++ b/include/linux/iio/common/cros_ec_sensors_core.h
@@ -12,6 +12,7 @@
 #include <linux/irqreturn.h>
 #include <linux/platform_data/cros_ec_commands.h>
 #include <linux/platform_data/cros_ec_proto.h>
+#include <linux/platform_data/cros_ec_sensorhub.h>
 
 enum {
 	CROS_EC_SENSOR_X,
@@ -32,6 +33,8 @@ enum {
 /* Minimum sampling period to use when device is suspending */
 #define CROS_EC_MIN_SUSPEND_SAMPLING_FREQUENCY 1000  /* 1 second */
 
+typedef irqreturn_t (*cros_ec_sensors_capture_t)(int irq, void *p);
+
 /**
  * struct cros_ec_sensors_core_state - state data for EC sensors IIO driver
  * @ec:				cros EC device structure
@@ -87,9 +90,14 @@ int cros_ec_sensors_read_cmd(struct iio_dev *indio_dev, unsigned long scan_mask,
 
 struct platform_device;
 int cros_ec_sensors_core_init(struct platform_device *pdev,
-			      struct iio_dev *indio_dev, bool physical_device);
+			      struct iio_dev *indio_dev, bool physical_device,
+			      cros_ec_sensors_capture_t trigger_capture,
+			      cros_ec_sensorhub_push_data_cb_t push_data);
 
 irqreturn_t cros_ec_sensors_capture(int irq, void *p);
+int cros_ec_sensors_push_data(struct iio_dev *indio_dev,
+			      s16 *data,
+			      s64 timestamp);
 
 int cros_ec_motion_send_host_cmd(struct cros_ec_sensors_core_state *st,
 				 u16 opt_length);
-- 
2.25.1.696.g5e7596f4ac-goog


^ permalink raw reply	[flat|nested] 15+ messages in thread

* [PATCH v6 07/11] iio: cros_ec: Remove pm function
  2020-03-24 20:27 [PATCH v6 00/11] Cros EC sensor hub FIFO support Gwendal Grignou
                   ` (5 preceding siblings ...)
  2020-03-24 20:27 ` [PATCH v6 06/11] iio: cros_ec: Register to cros_ec_sensorhub when EC supports FIFO Gwendal Grignou
@ 2020-03-24 20:27 ` Gwendal Grignou
  2020-03-24 20:27 ` [PATCH v6 08/11] iio: cros_ec: Expose hwfifo_timeout Gwendal Grignou
                   ` (4 subsequent siblings)
  11 siblings, 0 replies; 15+ messages in thread
From: Gwendal Grignou @ 2020-03-24 20:27 UTC (permalink / raw)
  To: bleung, enric.balletbo, Jonathan.Cameron
  Cc: linux-iio, linux-kernel, Gwendal Grignou, Lee Jones

Since cros_ec_sensorhub is shutting down the FIFO when the device
suspends, no need to slow down the EC sampling period rate.
It was necesseary to do that before command CMD_FIFO_INT_ENABLE was
introduced, but now all supported chromebooks have it.

Acked-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Acked-by: Enric Balletbo i Serra <enric.balletbo@collabora.com>
Acked-by: Lee Jones <lee.jones@linaro.org>
Signed-off-by: Gwendal Grignou <gwendal@chromium.org>
---
Changes in v6:
- No changes.
Changes in v5:
  Added ack.
No changes in v4, v3.
New in v2.

 .../cros_ec_sensors/cros_ec_lid_angle.c       |  1 -
 .../common/cros_ec_sensors/cros_ec_sensors.c  |  1 -
 .../cros_ec_sensors/cros_ec_sensors_core.c    | 47 -------------------
 drivers/iio/light/cros_ec_light_prox.c        |  1 -
 .../linux/iio/common/cros_ec_sensors_core.h   |  5 --
 5 files changed, 55 deletions(-)

diff --git a/drivers/iio/common/cros_ec_sensors/cros_ec_lid_angle.c b/drivers/iio/common/cros_ec_sensors/cros_ec_lid_angle.c
index e30a59fcf0f95..af801e203623e 100644
--- a/drivers/iio/common/cros_ec_sensors/cros_ec_lid_angle.c
+++ b/drivers/iio/common/cros_ec_sensors/cros_ec_lid_angle.c
@@ -127,7 +127,6 @@ MODULE_DEVICE_TABLE(platform, cros_ec_lid_angle_ids);
 static struct platform_driver cros_ec_lid_angle_platform_driver = {
 	.driver = {
 		.name	= DRV_NAME,
-		.pm	= &cros_ec_sensors_pm_ops,
 	},
 	.probe		= cros_ec_lid_angle_probe,
 	.id_table	= cros_ec_lid_angle_ids,
diff --git a/drivers/iio/common/cros_ec_sensors/cros_ec_sensors.c b/drivers/iio/common/cros_ec_sensors/cros_ec_sensors.c
index 711134d67ddee..fad21a90bc7e8 100644
--- a/drivers/iio/common/cros_ec_sensors/cros_ec_sensors.c
+++ b/drivers/iio/common/cros_ec_sensors/cros_ec_sensors.c
@@ -314,7 +314,6 @@ MODULE_DEVICE_TABLE(platform, cros_ec_sensors_ids);
 static struct platform_driver cros_ec_sensors_platform_driver = {
 	.driver = {
 		.name	= "cros-ec-sensors",
-		.pm	= &cros_ec_sensors_pm_ops,
 	},
 	.probe		= cros_ec_sensors_probe,
 	.id_table	= cros_ec_sensors_ids,
diff --git a/drivers/iio/common/cros_ec_sensors/cros_ec_sensors_core.c b/drivers/iio/common/cros_ec_sensors/cros_ec_sensors_core.c
index 01513cb933653..a1ecbd55ea767 100644
--- a/drivers/iio/common/cros_ec_sensors/cros_ec_sensors_core.c
+++ b/drivers/iio/common/cros_ec_sensors/cros_ec_sensors_core.c
@@ -738,52 +738,5 @@ int cros_ec_sensors_core_write(struct cros_ec_sensors_core_state *st,
 }
 EXPORT_SYMBOL_GPL(cros_ec_sensors_core_write);
 
-static int __maybe_unused cros_ec_sensors_prepare(struct device *dev)
-{
-	struct iio_dev *indio_dev = dev_get_drvdata(dev);
-	struct cros_ec_sensors_core_state *st = iio_priv(indio_dev);
-
-	if (st->curr_sampl_freq == 0)
-		return 0;
-
-	/*
-	 * If the sensors are sampled at high frequency, we will not be able to
-	 * sleep. Set sampling to a long period if necessary.
-	 */
-	if (st->curr_sampl_freq < CROS_EC_MIN_SUSPEND_SAMPLING_FREQUENCY) {
-		mutex_lock(&st->cmd_lock);
-		st->param.cmd = MOTIONSENSE_CMD_EC_RATE;
-		st->param.ec_rate.data = CROS_EC_MIN_SUSPEND_SAMPLING_FREQUENCY;
-		cros_ec_motion_send_host_cmd(st, 0);
-		mutex_unlock(&st->cmd_lock);
-	}
-	return 0;
-}
-
-static void __maybe_unused cros_ec_sensors_complete(struct device *dev)
-{
-	struct iio_dev *indio_dev = dev_get_drvdata(dev);
-	struct cros_ec_sensors_core_state *st = iio_priv(indio_dev);
-
-	if (st->curr_sampl_freq == 0)
-		return;
-
-	if (st->curr_sampl_freq < CROS_EC_MIN_SUSPEND_SAMPLING_FREQUENCY) {
-		mutex_lock(&st->cmd_lock);
-		st->param.cmd = MOTIONSENSE_CMD_EC_RATE;
-		st->param.ec_rate.data = st->curr_sampl_freq;
-		cros_ec_motion_send_host_cmd(st, 0);
-		mutex_unlock(&st->cmd_lock);
-	}
-}
-
-const struct dev_pm_ops cros_ec_sensors_pm_ops = {
-#ifdef CONFIG_PM_SLEEP
-	.prepare = cros_ec_sensors_prepare,
-	.complete = cros_ec_sensors_complete
-#endif
-};
-EXPORT_SYMBOL_GPL(cros_ec_sensors_pm_ops);
-
 MODULE_DESCRIPTION("ChromeOS EC sensor hub core functions");
 MODULE_LICENSE("GPL v2");
diff --git a/drivers/iio/light/cros_ec_light_prox.c b/drivers/iio/light/cros_ec_light_prox.c
index 03c951ff4a3c3..e10b35de4c2fa 100644
--- a/drivers/iio/light/cros_ec_light_prox.c
+++ b/drivers/iio/light/cros_ec_light_prox.c
@@ -255,7 +255,6 @@ MODULE_DEVICE_TABLE(platform, cros_ec_light_prox_ids);
 static struct platform_driver cros_ec_light_prox_platform_driver = {
 	.driver = {
 		.name	= "cros-ec-light-prox",
-		.pm	= &cros_ec_sensors_pm_ops,
 	},
 	.probe		= cros_ec_light_prox_probe,
 	.id_table	= cros_ec_light_prox_ids,
diff --git a/include/linux/iio/common/cros_ec_sensors_core.h b/include/linux/iio/common/cros_ec_sensors_core.h
index b8f573ca9dcc9..96ea4551945e2 100644
--- a/include/linux/iio/common/cros_ec_sensors_core.h
+++ b/include/linux/iio/common/cros_ec_sensors_core.h
@@ -30,9 +30,6 @@ enum {
  */
 #define CROS_EC_SAMPLE_SIZE  (sizeof(s64) * 2)
 
-/* Minimum sampling period to use when device is suspending */
-#define CROS_EC_MIN_SUSPEND_SAMPLING_FREQUENCY 1000  /* 1 second */
-
 typedef irqreturn_t (*cros_ec_sensors_capture_t)(int irq, void *p);
 
 /**
@@ -117,8 +114,6 @@ int cros_ec_sensors_core_write(struct cros_ec_sensors_core_state *st,
 			       struct iio_chan_spec const *chan,
 			       int val, int val2, long mask);
 
-extern const struct dev_pm_ops cros_ec_sensors_pm_ops;
-
 /* List of extended channel specification for all sensors */
 extern const struct iio_chan_spec_ext_info cros_ec_sensors_ext_info[];
 
-- 
2.25.1.696.g5e7596f4ac-goog


^ permalink raw reply	[flat|nested] 15+ messages in thread

* [PATCH v6 08/11] iio: cros_ec: Expose hwfifo_timeout
  2020-03-24 20:27 [PATCH v6 00/11] Cros EC sensor hub FIFO support Gwendal Grignou
                   ` (6 preceding siblings ...)
  2020-03-24 20:27 ` [PATCH v6 07/11] iio: cros_ec: Remove pm function Gwendal Grignou
@ 2020-03-24 20:27 ` Gwendal Grignou
  2020-03-24 20:27 ` [PATCH v6 09/11] iio: cros_ec: Report hwfifo_watermark_max Gwendal Grignou
                   ` (3 subsequent siblings)
  11 siblings, 0 replies; 15+ messages in thread
From: Gwendal Grignou @ 2020-03-24 20:27 UTC (permalink / raw)
  To: bleung, enric.balletbo, Jonathan.Cameron
  Cc: linux-iio, linux-kernel, Gwendal Grignou

Expose EC minimal interrupt period through buffer/hwfifo_timeout:
- Maximal timeout is limited to 65s.
- When timeout for all sensors is set to 0, EC will not send events,
  even if the sensor sampling rate is greater than 0.

Rename frequency to sampling_frequency to match IIO ABI.

Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Gwendal Grignou <gwendal@chromium.org>
---
Changes in v6:
- No changes.
Changes in v5:
  Added ack.
Changes in v4:
- Check patch with --strict option
    Alignement
No changes in v3.
Changes in v2:
- Register fifo_attributes in sensors drivers that previously advertise
  that feature.

 .../common/cros_ec_sensors/cros_ec_sensors.c  |  3 +-
 .../cros_ec_sensors/cros_ec_sensors_core.c    | 95 ++++++++++++++-----
 drivers/iio/light/cros_ec_light_prox.c        |  5 +-
 drivers/iio/pressure/cros_ec_baro.c           |  5 +-
 .../linux/iio/common/cros_ec_sensors_core.h   |  4 +-
 5 files changed, 82 insertions(+), 30 deletions(-)

diff --git a/drivers/iio/common/cros_ec_sensors/cros_ec_sensors.c b/drivers/iio/common/cros_ec_sensors/cros_ec_sensors.c
index fad21a90bc7e8..a66941fdb3855 100644
--- a/drivers/iio/common/cros_ec_sensors/cros_ec_sensors.c
+++ b/drivers/iio/common/cros_ec_sensors/cros_ec_sensors.c
@@ -236,6 +236,8 @@ static int cros_ec_sensors_probe(struct platform_device *pdev)
 	if (ret)
 		return ret;
 
+	iio_buffer_set_attrs(indio_dev->buffer, cros_ec_sensor_fifo_attributes);
+
 	indio_dev->info = &ec_sensors_info;
 	state = iio_priv(indio_dev);
 	for (channel = state->channels, i = CROS_EC_SENSOR_X;
@@ -247,7 +249,6 @@ static int cros_ec_sensors_probe(struct platform_device *pdev)
 			BIT(IIO_CHAN_INFO_CALIBSCALE);
 		channel->info_mask_shared_by_all =
 			BIT(IIO_CHAN_INFO_SCALE) |
-			BIT(IIO_CHAN_INFO_FREQUENCY) |
 			BIT(IIO_CHAN_INFO_SAMP_FREQ);
 		channel->info_mask_shared_by_all_available =
 			BIT(IIO_CHAN_INFO_SAMP_FREQ);
diff --git a/drivers/iio/common/cros_ec_sensors/cros_ec_sensors_core.c b/drivers/iio/common/cros_ec_sensors/cros_ec_sensors_core.c
index a1ecbd55ea767..b8eac7e5d5e5b 100644
--- a/drivers/iio/common/cros_ec_sensors/cros_ec_sensors_core.c
+++ b/drivers/iio/common/cros_ec_sensors/cros_ec_sensors_core.c
@@ -11,6 +11,7 @@
 #include <linux/iio/common/cros_ec_sensors_core.h>
 #include <linux/iio/iio.h>
 #include <linux/iio/kfifo_buf.h>
+#include <linux/iio/sysfs.h>
 #include <linux/iio/trigger_consumer.h>
 #include <linux/iio/triggered_buffer.h>
 #include <linux/kernel.h>
@@ -83,6 +84,77 @@ static void get_default_min_max_freq(enum motionsensor_type type,
 	}
 }
 
+static int cros_ec_sensor_set_ec_rate(struct cros_ec_sensors_core_state *st,
+				      int rate)
+{
+	int ret;
+
+	if (rate > U16_MAX)
+		rate = U16_MAX;
+
+	mutex_lock(&st->cmd_lock);
+	st->param.cmd = MOTIONSENSE_CMD_EC_RATE;
+	st->param.ec_rate.data = rate;
+	ret = cros_ec_motion_send_host_cmd(st, 0);
+	mutex_unlock(&st->cmd_lock);
+	return ret;
+}
+
+static ssize_t cros_ec_sensor_set_report_latency(struct device *dev,
+						 struct device_attribute *attr,
+						 const char *buf, size_t len)
+{
+	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
+	struct cros_ec_sensors_core_state *st = iio_priv(indio_dev);
+	int integer, fract, ret;
+	int latency;
+
+	ret = iio_str_to_fixpoint(buf, 100000, &integer, &fract);
+	if (ret)
+		return ret;
+
+	/* EC rate is in ms. */
+	latency = integer * 1000 + fract / 1000;
+	ret = cros_ec_sensor_set_ec_rate(st, latency);
+	if (ret < 0)
+		return ret;
+
+	return len;
+}
+
+static ssize_t cros_ec_sensor_get_report_latency(struct device *dev,
+						 struct device_attribute *attr,
+						 char *buf)
+{
+	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
+	struct cros_ec_sensors_core_state *st = iio_priv(indio_dev);
+	int latency, ret;
+
+	mutex_lock(&st->cmd_lock);
+	st->param.cmd = MOTIONSENSE_CMD_EC_RATE;
+	st->param.ec_rate.data = EC_MOTION_SENSE_NO_VALUE;
+
+	ret = cros_ec_motion_send_host_cmd(st, 0);
+	latency = st->resp->ec_rate.ret;
+	mutex_unlock(&st->cmd_lock);
+	if (ret < 0)
+		return ret;
+
+	return sprintf(buf, "%d.%06u\n",
+		       latency / 1000,
+		       (latency % 1000) * 1000);
+}
+
+static IIO_DEVICE_ATTR(hwfifo_timeout, 0644,
+		       cros_ec_sensor_get_report_latency,
+		       cros_ec_sensor_set_report_latency, 0);
+
+const struct attribute *cros_ec_sensor_fifo_attributes[] = {
+	&iio_dev_attr_hwfifo_timeout.dev_attr.attr,
+	NULL,
+};
+EXPORT_SYMBOL_GPL(cros_ec_sensor_fifo_attributes);
+
 int cros_ec_sensors_push_data(struct iio_dev *indio_dev,
 			      s16 *data,
 			      s64 timestamp)
@@ -631,18 +703,6 @@ int cros_ec_sensors_core_read(struct cros_ec_sensors_core_state *st,
 
 	switch (mask) {
 	case IIO_CHAN_INFO_SAMP_FREQ:
-		st->param.cmd = MOTIONSENSE_CMD_EC_RATE;
-		st->param.ec_rate.data =
-			EC_MOTION_SENSE_NO_VALUE;
-
-		ret = cros_ec_motion_send_host_cmd(st, 0);
-		if (ret)
-			break;
-
-		*val = st->resp->ec_rate.ret;
-		ret = IIO_VAL_INT;
-		break;
-	case IIO_CHAN_INFO_FREQUENCY:
 		st->param.cmd = MOTIONSENSE_CMD_SENSOR_ODR;
 		st->param.sensor_odr.data =
 			EC_MOTION_SENSE_NO_VALUE;
@@ -712,7 +772,7 @@ int cros_ec_sensors_core_write(struct cros_ec_sensors_core_state *st,
 	int ret;
 
 	switch (mask) {
-	case IIO_CHAN_INFO_FREQUENCY:
+	case IIO_CHAN_INFO_SAMP_FREQ:
 		st->param.cmd = MOTIONSENSE_CMD_SENSOR_ODR;
 		st->param.sensor_odr.data = val;
 
@@ -721,15 +781,6 @@ int cros_ec_sensors_core_write(struct cros_ec_sensors_core_state *st,
 
 		ret = cros_ec_motion_send_host_cmd(st, 0);
 		break;
-	case IIO_CHAN_INFO_SAMP_FREQ:
-		st->param.cmd = MOTIONSENSE_CMD_EC_RATE;
-		st->param.ec_rate.data = val;
-
-		ret = cros_ec_motion_send_host_cmd(st, 0);
-		if (ret)
-			break;
-		st->curr_sampl_freq = val;
-		break;
 	default:
 		ret = -EINVAL;
 		break;
diff --git a/drivers/iio/light/cros_ec_light_prox.c b/drivers/iio/light/cros_ec_light_prox.c
index e10b35de4c2fa..2198b50909ed0 100644
--- a/drivers/iio/light/cros_ec_light_prox.c
+++ b/drivers/iio/light/cros_ec_light_prox.c
@@ -183,6 +183,8 @@ static int cros_ec_light_prox_probe(struct platform_device *pdev)
 	if (ret)
 		return ret;
 
+	iio_buffer_set_attrs(indio_dev->buffer, cros_ec_sensor_fifo_attributes);
+
 	indio_dev->info = &cros_ec_light_prox_info;
 	state = iio_priv(indio_dev);
 	state->core.type = state->core.resp->info.type;
@@ -191,8 +193,7 @@ static int cros_ec_light_prox_probe(struct platform_device *pdev)
 
 	/* Common part */
 	channel->info_mask_shared_by_all =
-		BIT(IIO_CHAN_INFO_SAMP_FREQ) |
-		BIT(IIO_CHAN_INFO_FREQUENCY);
+		BIT(IIO_CHAN_INFO_SAMP_FREQ);
 	channel->info_mask_shared_by_all_available =
 		BIT(IIO_CHAN_INFO_SAMP_FREQ);
 	channel->scan_type.realbits = CROS_EC_SENSOR_BITS;
diff --git a/drivers/iio/pressure/cros_ec_baro.c b/drivers/iio/pressure/cros_ec_baro.c
index 6add499f11aa6..c079b89600824 100644
--- a/drivers/iio/pressure/cros_ec_baro.c
+++ b/drivers/iio/pressure/cros_ec_baro.c
@@ -140,6 +140,8 @@ static int cros_ec_baro_probe(struct platform_device *pdev)
 	if (ret)
 		return ret;
 
+	iio_buffer_set_attrs(indio_dev->buffer, cros_ec_sensor_fifo_attributes);
+
 	indio_dev->info = &cros_ec_baro_info;
 	state = iio_priv(indio_dev);
 	state->core.type = state->core.resp->info.type;
@@ -149,8 +151,7 @@ static int cros_ec_baro_probe(struct platform_device *pdev)
 	channel->info_mask_separate = BIT(IIO_CHAN_INFO_RAW);
 	channel->info_mask_shared_by_all =
 		BIT(IIO_CHAN_INFO_SCALE) |
-		BIT(IIO_CHAN_INFO_SAMP_FREQ) |
-		BIT(IIO_CHAN_INFO_FREQUENCY);
+		BIT(IIO_CHAN_INFO_SAMP_FREQ);
 	channel->info_mask_shared_by_all_available =
 		BIT(IIO_CHAN_INFO_SAMP_FREQ);
 	channel->scan_type.realbits = CROS_EC_SENSOR_BITS;
diff --git a/include/linux/iio/common/cros_ec_sensors_core.h b/include/linux/iio/common/cros_ec_sensors_core.h
index 96ea4551945e2..5b0acc14c891f 100644
--- a/include/linux/iio/common/cros_ec_sensors_core.h
+++ b/include/linux/iio/common/cros_ec_sensors_core.h
@@ -50,7 +50,6 @@ typedef irqreturn_t (*cros_ec_sensors_capture_t)(int irq, void *p);
  *				the timestamp. The timestamp is always last and
  *				is always 8-byte aligned.
  * @read_ec_sensors_data:	function used for accessing sensors values
- * @cuur_sampl_freq:		current sampling period
  */
 struct cros_ec_sensors_core_state {
 	struct cros_ec_device *ec;
@@ -73,8 +72,6 @@ struct cros_ec_sensors_core_state {
 	int (*read_ec_sensors_data)(struct iio_dev *indio_dev,
 				    unsigned long scan_mask, s16 *data);
 
-	int curr_sampl_freq;
-
 	/* Table of known available frequencies : 0, Min and Max in mHz */
 	int frequencies[3];
 };
@@ -116,5 +113,6 @@ int cros_ec_sensors_core_write(struct cros_ec_sensors_core_state *st,
 
 /* List of extended channel specification for all sensors */
 extern const struct iio_chan_spec_ext_info cros_ec_sensors_ext_info[];
+extern const struct attribute *cros_ec_sensor_fifo_attributes[];
 
 #endif  /* __CROS_EC_SENSORS_CORE_H */
-- 
2.25.1.696.g5e7596f4ac-goog


^ permalink raw reply	[flat|nested] 15+ messages in thread

* [PATCH v6 09/11] iio: cros_ec: Report hwfifo_watermark_max
  2020-03-24 20:27 [PATCH v6 00/11] Cros EC sensor hub FIFO support Gwendal Grignou
                   ` (7 preceding siblings ...)
  2020-03-24 20:27 ` [PATCH v6 08/11] iio: cros_ec: Expose hwfifo_timeout Gwendal Grignou
@ 2020-03-24 20:27 ` Gwendal Grignou
  2020-03-24 20:27 ` [PATCH v6 10/11] iio: cros_ec: Use Hertz as unit for sampling frequency Gwendal Grignou
                   ` (2 subsequent siblings)
  11 siblings, 0 replies; 15+ messages in thread
From: Gwendal Grignou @ 2020-03-24 20:27 UTC (permalink / raw)
  To: bleung, enric.balletbo, Jonathan.Cameron
  Cc: linux-iio, linux-kernel, Gwendal Grignou

Report the maximum amount of sample the EC can hold.
This is not tunable, but can be useful for application to find out the
maximum amount of time it can sleep when hwfifo_timeout is set to a
large number.

Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Gwendal Grignou <gwendal@chromium.org>
---
Changes in v6:
- No changes.
Changes in v5:
  Added ack.
Changes in v4:
- Check patch with --strict option
    Alignement
No changes in v3.
Changes in v2:
- Remove double lines, add line before return for visibility.

 .../cros_ec_sensors/cros_ec_sensors_core.c    | 33 +++++++++++++++++--
 .../linux/iio/common/cros_ec_sensors_core.h   |  3 ++
 2 files changed, 34 insertions(+), 2 deletions(-)

diff --git a/drivers/iio/common/cros_ec_sensors/cros_ec_sensors_core.c b/drivers/iio/common/cros_ec_sensors/cros_ec_sensors_core.c
index b8eac7e5d5e5b..67e8eff038cf5 100644
--- a/drivers/iio/common/cros_ec_sensors/cros_ec_sensors_core.c
+++ b/drivers/iio/common/cros_ec_sensors/cros_ec_sensors_core.c
@@ -22,6 +22,12 @@
 #include <linux/platform_data/cros_ec_sensorhub.h>
 #include <linux/platform_device.h>
 
+/*
+ * Hard coded to the first device to support sensor fifo.  The EC has a 2048
+ * byte fifo and will trigger an interrupt when fifo is 2/3 full.
+ */
+#define CROS_EC_FIFO_SIZE (2048 * 2 / 3)
+
 static char *cros_ec_loc[] = {
 	[MOTIONSENSE_LOC_BASE] = "base",
 	[MOTIONSENSE_LOC_LID] = "lid",
@@ -55,8 +61,15 @@ static int cros_ec_get_host_cmd_version_mask(struct cros_ec_device *ec_dev,
 
 static void get_default_min_max_freq(enum motionsensor_type type,
 				     u32 *min_freq,
-				     u32 *max_freq)
+				     u32 *max_freq,
+				     u32 *max_fifo_events)
 {
+	/*
+	 * We don't know fifo size, set to size previously used by older
+	 * hardware.
+	 */
+	*max_fifo_events = CROS_EC_FIFO_SIZE;
+
 	switch (type) {
 	case MOTIONSENSE_TYPE_ACCEL:
 	case MOTIONSENSE_TYPE_GYRO:
@@ -149,8 +162,21 @@ static IIO_DEVICE_ATTR(hwfifo_timeout, 0644,
 		       cros_ec_sensor_get_report_latency,
 		       cros_ec_sensor_set_report_latency, 0);
 
+static ssize_t hwfifo_watermark_max_show(struct device *dev,
+					 struct device_attribute *attr,
+					 char *buf)
+{
+	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
+	struct cros_ec_sensors_core_state *st = iio_priv(indio_dev);
+
+	return sprintf(buf, "%d\n", st->fifo_max_event_count);
+}
+
+static IIO_DEVICE_ATTR_RO(hwfifo_watermark_max, 0);
+
 const struct attribute *cros_ec_sensor_fifo_attributes[] = {
 	&iio_dev_attr_hwfifo_timeout.dev_attr.attr,
+	&iio_dev_attr_hwfifo_watermark_max.dev_attr.attr,
 	NULL,
 };
 EXPORT_SYMBOL_GPL(cros_ec_sensor_fifo_attributes);
@@ -279,12 +305,15 @@ int cros_ec_sensors_core_init(struct platform_device *pdev,
 		if (state->msg->version < 3) {
 			get_default_min_max_freq(state->resp->info.type,
 						 &state->frequencies[1],
-						 &state->frequencies[2]);
+						 &state->frequencies[2],
+						 &state->fifo_max_event_count);
 		} else {
 			state->frequencies[1] =
 			    state->resp->info_3.min_frequency;
 			state->frequencies[2] =
 			    state->resp->info_3.max_frequency;
+			state->fifo_max_event_count =
+			    state->resp->info_3.fifo_max_event_count;
 		}
 
 		if (cros_ec_check_features(ec, EC_FEATURE_MOTION_SENSE_FIFO)) {
diff --git a/include/linux/iio/common/cros_ec_sensors_core.h b/include/linux/iio/common/cros_ec_sensors_core.h
index 5b0acc14c891f..bc26ae2e32729 100644
--- a/include/linux/iio/common/cros_ec_sensors_core.h
+++ b/include/linux/iio/common/cros_ec_sensors_core.h
@@ -50,6 +50,7 @@ typedef irqreturn_t (*cros_ec_sensors_capture_t)(int irq, void *p);
  *				the timestamp. The timestamp is always last and
  *				is always 8-byte aligned.
  * @read_ec_sensors_data:	function used for accessing sensors values
+ * @fifo_max_event_count:	Size of the EC sensor FIFO
  */
 struct cros_ec_sensors_core_state {
 	struct cros_ec_device *ec;
@@ -72,6 +73,8 @@ struct cros_ec_sensors_core_state {
 	int (*read_ec_sensors_data)(struct iio_dev *indio_dev,
 				    unsigned long scan_mask, s16 *data);
 
+	u32 fifo_max_event_count;
+
 	/* Table of known available frequencies : 0, Min and Max in mHz */
 	int frequencies[3];
 };
-- 
2.25.1.696.g5e7596f4ac-goog


^ permalink raw reply	[flat|nested] 15+ messages in thread

* [PATCH v6 10/11] iio: cros_ec: Use Hertz as unit for sampling frequency
  2020-03-24 20:27 [PATCH v6 00/11] Cros EC sensor hub FIFO support Gwendal Grignou
                   ` (8 preceding siblings ...)
  2020-03-24 20:27 ` [PATCH v6 09/11] iio: cros_ec: Report hwfifo_watermark_max Gwendal Grignou
@ 2020-03-24 20:27 ` Gwendal Grignou
  2020-03-24 20:27 ` [PATCH v6 11/11] iio: cros_ec: flush as hwfifo attribute Gwendal Grignou
  2020-03-25 15:59 ` [PATCH v6 00/11] Cros EC sensor hub FIFO support Andy Shevchenko
  11 siblings, 0 replies; 15+ messages in thread
From: Gwendal Grignou @ 2020-03-24 20:27 UTC (permalink / raw)
  To: bleung, enric.balletbo, Jonathan.Cameron
  Cc: linux-iio, linux-kernel, Gwendal Grignou

To be compliant with other sensors, set and get sensor sampling
frequency in Hz, not mHz.

Fixes: ae7b02ad2f32 ("iio: common: cros_ec_sensors: Expose
cros_ec_sensors frequency range via iio sysfs")

Acked-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Gwendal Grignou <gwendal@chromium.org>
---
Changes in v6:
- No changes.
Changes in v5:
  Added ack.
Changes in v4:
- Check patch with --strict option
    Alignement
No changes in v3.
No changes in v2.

 .../cros_ec_sensors/cros_ec_sensors_core.c    | 32 +++++++++++--------
 .../linux/iio/common/cros_ec_sensors_core.h   |  6 ++--
 2 files changed, 22 insertions(+), 16 deletions(-)

diff --git a/drivers/iio/common/cros_ec_sensors/cros_ec_sensors_core.c b/drivers/iio/common/cros_ec_sensors/cros_ec_sensors_core.c
index 67e8eff038cf5..c831915ca7e56 100644
--- a/drivers/iio/common/cros_ec_sensors/cros_ec_sensors_core.c
+++ b/drivers/iio/common/cros_ec_sensors/cros_ec_sensors_core.c
@@ -253,6 +253,7 @@ int cros_ec_sensors_core_init(struct platform_device *pdev,
 	struct cros_ec_dev *ec = sensor_hub->ec;
 	struct cros_ec_sensor_platform *sensor_platform = dev_get_platdata(dev);
 	u32 ver_mask;
+	int frequencies[ARRAY_SIZE(state->frequencies) / 2] = { 0 };
 	int ret, i;
 
 	platform_set_drvdata(pdev, indio_dev);
@@ -301,20 +302,22 @@ int cros_ec_sensors_core_init(struct platform_device *pdev,
 			state->calib[i].scale = MOTION_SENSE_DEFAULT_SCALE;
 
 		/* 0 is a correct value used to stop the device */
-		state->frequencies[0] = 0;
 		if (state->msg->version < 3) {
 			get_default_min_max_freq(state->resp->info.type,
-						 &state->frequencies[1],
-						 &state->frequencies[2],
+						 &frequencies[1],
+						 &frequencies[2],
 						 &state->fifo_max_event_count);
 		} else {
-			state->frequencies[1] =
-			    state->resp->info_3.min_frequency;
-			state->frequencies[2] =
-			    state->resp->info_3.max_frequency;
+			frequencies[1] = state->resp->info_3.min_frequency;
+			frequencies[2] = state->resp->info_3.max_frequency;
 			state->fifo_max_event_count =
 			    state->resp->info_3.fifo_max_event_count;
 		}
+		for (i = 0; i < ARRAY_SIZE(frequencies); i++) {
+			state->frequencies[2 * i] = frequencies[i] / 1000;
+			state->frequencies[2 * i + 1] =
+				(frequencies[i] % 1000) * 1000;
+		}
 
 		if (cros_ec_check_features(ec, EC_FEATURE_MOTION_SENSE_FIFO)) {
 			/*
@@ -728,7 +731,7 @@ int cros_ec_sensors_core_read(struct cros_ec_sensors_core_state *st,
 			  struct iio_chan_spec const *chan,
 			  int *val, int *val2, long mask)
 {
-	int ret;
+	int ret, frequency;
 
 	switch (mask) {
 	case IIO_CHAN_INFO_SAMP_FREQ:
@@ -740,8 +743,10 @@ int cros_ec_sensors_core_read(struct cros_ec_sensors_core_state *st,
 		if (ret)
 			break;
 
-		*val = st->resp->sensor_odr.ret;
-		ret = IIO_VAL_INT;
+		frequency = st->resp->sensor_odr.ret;
+		*val = frequency / 1000;
+		*val2 = (frequency % 1000) * 1000;
+		ret = IIO_VAL_INT_PLUS_MICRO;
 		break;
 	default:
 		ret = -EINVAL;
@@ -776,7 +781,7 @@ int cros_ec_sensors_core_read_avail(struct iio_dev *indio_dev,
 	case IIO_CHAN_INFO_SAMP_FREQ:
 		*length = ARRAY_SIZE(state->frequencies);
 		*vals = (const int *)&state->frequencies;
-		*type = IIO_VAL_INT;
+		*type = IIO_VAL_INT_PLUS_MICRO;
 		return IIO_AVAIL_LIST;
 	}
 
@@ -798,12 +803,13 @@ int cros_ec_sensors_core_write(struct cros_ec_sensors_core_state *st,
 			       struct iio_chan_spec const *chan,
 			       int val, int val2, long mask)
 {
-	int ret;
+	int ret, frequency;
 
 	switch (mask) {
 	case IIO_CHAN_INFO_SAMP_FREQ:
+		frequency = val * 1000 + val2 / 1000;
 		st->param.cmd = MOTIONSENSE_CMD_SENSOR_ODR;
-		st->param.sensor_odr.data = val;
+		st->param.sensor_odr.data = frequency;
 
 		/* Always roundup, so caller gets at least what it asks for. */
 		st->param.sensor_odr.roundup = 1;
diff --git a/include/linux/iio/common/cros_ec_sensors_core.h b/include/linux/iio/common/cros_ec_sensors_core.h
index bc26ae2e32729..7bc961defa87e 100644
--- a/include/linux/iio/common/cros_ec_sensors_core.h
+++ b/include/linux/iio/common/cros_ec_sensors_core.h
@@ -51,6 +51,8 @@ typedef irqreturn_t (*cros_ec_sensors_capture_t)(int irq, void *p);
  *				is always 8-byte aligned.
  * @read_ec_sensors_data:	function used for accessing sensors values
  * @fifo_max_event_count:	Size of the EC sensor FIFO
+ * @frequencies:		Table of known available frequencies:
+ *				0, Min and Max in mHz
  */
 struct cros_ec_sensors_core_state {
 	struct cros_ec_device *ec;
@@ -74,9 +76,7 @@ struct cros_ec_sensors_core_state {
 				    unsigned long scan_mask, s16 *data);
 
 	u32 fifo_max_event_count;
-
-	/* Table of known available frequencies : 0, Min and Max in mHz */
-	int frequencies[3];
+	int frequencies[6];
 };
 
 int cros_ec_sensors_read_lpc(struct iio_dev *indio_dev, unsigned long scan_mask,
-- 
2.25.1.696.g5e7596f4ac-goog


^ permalink raw reply	[flat|nested] 15+ messages in thread

* [PATCH v6 11/11] iio: cros_ec: flush as hwfifo attribute
  2020-03-24 20:27 [PATCH v6 00/11] Cros EC sensor hub FIFO support Gwendal Grignou
                   ` (9 preceding siblings ...)
  2020-03-24 20:27 ` [PATCH v6 10/11] iio: cros_ec: Use Hertz as unit for sampling frequency Gwendal Grignou
@ 2020-03-24 20:27 ` Gwendal Grignou
  2020-03-25 15:59 ` [PATCH v6 00/11] Cros EC sensor hub FIFO support Andy Shevchenko
  11 siblings, 0 replies; 15+ messages in thread
From: Gwendal Grignou @ 2020-03-24 20:27 UTC (permalink / raw)
  To: bleung, enric.balletbo, Jonathan.Cameron
  Cc: linux-iio, linux-kernel, Gwendal Grignou

Add buffer/hwfifo_flush. It is not part of the ABI, but it follows ST
and HID lead: Tells the sensor hub to send to the host all pending
sensor events.

Signed-off-by: Gwendal Grignou <gwendal@chromium.org>
---
New in v6.

 .../cros_ec_sensors/cros_ec_sensors_core.c    | 28 +++++++++++++++++++
 1 file changed, 28 insertions(+)

diff --git a/drivers/iio/common/cros_ec_sensors/cros_ec_sensors_core.c b/drivers/iio/common/cros_ec_sensors/cros_ec_sensors_core.c
index c831915ca7e56..aaf124a82e0e4 100644
--- a/drivers/iio/common/cros_ec_sensors/cros_ec_sensors_core.c
+++ b/drivers/iio/common/cros_ec_sensors/cros_ec_sensors_core.c
@@ -113,6 +113,33 @@ static int cros_ec_sensor_set_ec_rate(struct cros_ec_sensors_core_state *st,
 	return ret;
 }
 
+static ssize_t cros_ec_sensors_flush(struct device *dev,
+				     struct device_attribute *attr,
+				     const char *buf, size_t len)
+{
+	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
+	struct cros_ec_sensors_core_state *st = iio_priv(indio_dev);
+	int ret = 0;
+	bool flush;
+
+	ret = strtobool(buf, &flush);
+	if (ret < 0)
+		return ret;
+	if (!flush)
+		return -EINVAL;
+
+	mutex_lock(&st->cmd_lock);
+	st->param.cmd = MOTIONSENSE_CMD_FIFO_FLUSH;
+	ret = cros_ec_motion_send_host_cmd(st, 0);
+	if (ret != 0)
+		dev_warn(&indio_dev->dev, "Unable to flush sensor\n");
+	mutex_unlock(&st->cmd_lock);
+	return ret ? ret : len;
+}
+
+static IIO_DEVICE_ATTR(hwfifo_flush, 0644, NULL,
+		       cros_ec_sensors_flush, 0);
+
 static ssize_t cros_ec_sensor_set_report_latency(struct device *dev,
 						 struct device_attribute *attr,
 						 const char *buf, size_t len)
@@ -175,6 +202,7 @@ static ssize_t hwfifo_watermark_max_show(struct device *dev,
 static IIO_DEVICE_ATTR_RO(hwfifo_watermark_max, 0);
 
 const struct attribute *cros_ec_sensor_fifo_attributes[] = {
+	&iio_dev_attr_hwfifo_flush.dev_attr.attr,
 	&iio_dev_attr_hwfifo_timeout.dev_attr.attr,
 	&iio_dev_attr_hwfifo_watermark_max.dev_attr.attr,
 	NULL,
-- 
2.25.1.696.g5e7596f4ac-goog


^ permalink raw reply	[flat|nested] 15+ messages in thread

* Re: [PATCH v6 00/11] Cros EC sensor hub FIFO support
  2020-03-24 20:27 [PATCH v6 00/11] Cros EC sensor hub FIFO support Gwendal Grignou
                   ` (10 preceding siblings ...)
  2020-03-24 20:27 ` [PATCH v6 11/11] iio: cros_ec: flush as hwfifo attribute Gwendal Grignou
@ 2020-03-25 15:59 ` Andy Shevchenko
  11 siblings, 0 replies; 15+ messages in thread
From: Andy Shevchenko @ 2020-03-25 15:59 UTC (permalink / raw)
  To: Gwendal Grignou
  Cc: Benson Leung, Enric Balletbo i Serra, Jonathan Cameron,
	linux-iio, Linux Kernel Mailing List

On Tue, Mar 24, 2020 at 10:28 PM Gwendal Grignou <gwendal@chromium.org> wrote:
>
> This patchset adds a sensorhub driver for spreading sensor
> events coming from the Embedded controller sensor FIFO:
>
>        +---------------+ +--------------+ +----
>        | cros_ec_accel | | cros_ec_gyro | | ...
>        +---------------+ +--------------+ +----
>            id:0       \        id:1 |       / id:..
>                  +------------------------------+
>                  |       cros-ec-sensorhub      |
>                  +------------------------------+
>                  |           cros_ec_dev        |
>                  +------------------------------+
>                  | cros_ec_i2c, cros_ec_lpc, .. |
>                  +------------------------------+
>                                  |
>                                  EC
>
> When new sensors events are present, the EC raises and interrupt,
> sensorhub reads the FIFO and uses the 'id' field to spread the event to
> the proper IIO sensors. This stack is similar to the HID sensor input
> stack.
>
> The patch set allows the host to receive MEMS sensor sample
> asynchronously from ChromeOS Emebedded Controller (EC).
>
> Given the EC and the host are not synchronized, the timestamp generated
> by the EC drifts and the AP interrupt latency adds variable delay.
>
> When events arrive, the driver stores the time of the interrupt and use
> that information to convert the timestamp from the EC time domain to the
> AP time domain. To prevent the errors from the interrupt time variation,
> a median filter smooth the timestamp generation and prevents timestamps
> to go in the past.
>
> When a batch of sensor events arrives, the sensor hub ring code spreads
> the timestamps.
>
> The buffer interaface is presentid through the IIO ABI.
> And extra parameter - flush - (presents on HID and ST sensor hub
> implementation) force the EC to send accumulated events in its queue,
> without waiting for buffer hwfifo_timeout to expire.
>
> To access sensor data, we can use iio_readdev like:
>  iio_readdev -T 10000 -s 4 -b 2 iio:device4
>
> When FIFO is not supported by the EC, a trigger is present in the
> directory. After registering a trigger, setting sampling_frequency,
> the latest data collected by the sensor will be retrieved by the host
> when the trigger expires.
>
> When cros_ec_accel_legacy driver is used, no FIFO is supported and the
> sampling frequency for the accelerometers is hard coded at 10Hz.
>

Acked-by: Andy Shevchenko <andy.shevchenko@gmail.com> # for
drivers/platform/chrome bits

> Gwendal Grignou (11):
>   platform: chrome: sensorhub: Add FIFO support
>   platform: chrome: sensorhub: Add code to spread timestmap
>   platform: chrome: sensorhub: Add median filter
>   iio: cros_ec: Move function description to .c file
>   iio: expose iio_device_set_clock
>   iio: cros_ec: Register to cros_ec_sensorhub when EC supports FIFO
>   iio: cros_ec: Remove pm function
>   iio: cros_ec: Expose hwfifo_timeout
>   iio: cros_ec: Report hwfifo_watermark_max
>   iio: cros_ec: Use Hertz as unit for sampling frequency
>   iio: cros_ec: flush as hwfifo attribute
>
>  drivers/iio/accel/cros_ec_accel_legacy.c      |    8 +-
>  .../cros_ec_sensors/cros_ec_lid_angle.c       |    3 +-
>  .../common/cros_ec_sensors/cros_ec_sensors.c  |   13 +-
>  .../cros_ec_sensors/cros_ec_sensors_core.c    |  404 +++++--
>  drivers/iio/industrialio-core.c               |    8 +-
>  drivers/iio/light/cros_ec_light_prox.c        |   15 +-
>  drivers/iio/pressure/cros_ec_baro.c           |   14 +-
>  drivers/platform/chrome/Makefile              |    4 +-
>  drivers/platform/chrome/cros_ec_sensorhub.c   |  107 +-
>  .../platform/chrome/cros_ec_sensorhub_ring.c  | 1002 +++++++++++++++++
>  .../linux/iio/common/cros_ec_sensors_core.h   |  104 +-
>  include/linux/iio/iio.h                       |    2 +
>  .../linux/platform_data/cros_ec_sensorhub.h   |  166 +++
>  13 files changed, 1612 insertions(+), 238 deletions(-)
>  create mode 100644 drivers/platform/chrome/cros_ec_sensorhub_ring.c
>
> --
> 2.25.1.696.g5e7596f4ac-goog
>


-- 
With Best Regards,
Andy Shevchenko

^ permalink raw reply	[flat|nested] 15+ messages in thread

* Re: [PATCH v6 01/11] platform: chrome: sensorhub: Add FIFO support
  2020-03-24 20:27 ` [PATCH v6 01/11] platform: chrome: sensorhub: Add " Gwendal Grignou
@ 2020-03-25 16:28   ` Enric Balletbo i Serra
  2020-03-26  8:56     ` Gwendal Grignou
  0 siblings, 1 reply; 15+ messages in thread
From: Enric Balletbo i Serra @ 2020-03-25 16:28 UTC (permalink / raw)
  To: Gwendal Grignou, bleung, Jonathan.Cameron; +Cc: linux-iio, linux-kernel

Hi Gwendal,

Many thanks for sending this series upstream. Just one comment, other than that
looks good to me.

On 24/3/20 21:27, Gwendal Grignou wrote:
> cros_ec_sensorhub registers a listener and query motion sense FIFO,
> spread to iio sensors registers.
> 
> To test, we can use libiio:
> iiod&
> iio_readdev -u ip:localhost -T 10000 -s 25 -b 16 cros-ec-gyro | od -x
> 
> Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
> Signed-off-by: Gwendal Grignou <gwendal@chromium.org>

[snip]

> +/**
> + * cros_ec_sensorhub_ring_handler() - The trigger handler function
> + *
> + * @sensorhub: Sensor Hub object.
> + *
> + * Called by the notifier, process the EC sensor FIFO queue.
> + */
> +static void cros_ec_sensorhub_ring_handler(struct cros_ec_sensorhub *sensorhub)
> +{
> +	struct cros_ec_fifo_info *fifo_info = &sensorhub->fifo_info;
> +	struct cros_ec_dev *ec = sensorhub->ec;
> +	ktime_t fifo_timestamp, current_timestamp;
> +	int i, j, number_data, ret;
> +	unsigned long sensor_mask = 0;
> +	struct ec_response_motion_sensor_data *in;
> +	struct cros_ec_sensors_ring_sample *out, *last_out;
> +
> +	mutex_lock(&sensorhub->cmd_lock);
> +
> +	/* Get FIFO information if there are lost vectors. */
> +	if (fifo_info->info.total_lost) {
> +		/* Need to retrieve the number of lost vectors per sensor */
> +		sensorhub->params->cmd = MOTIONSENSE_CMD_FIFO_INFO;
> +		sensorhub->msg->outsize = 1;
> +		sensorhub->msg->insize =
> +			sizeof(struct ec_response_motion_sense_fifo_info) +
> +			sizeof(u16) * CROS_EC_SENSOR_MAX;
> +
> +		if (cros_ec_cmd_xfer_status(ec->ec_dev, sensorhub->msg) < 0)
> +			goto error;
> +
> +		memcpy(fifo_info, &sensorhub->resp->fifo_info,
> +		       sizeof(*fifo_info));
> +

Smatch is reporting:

cros_ec_sensorhub_ring_handler() error: memcpy() '&sensorhub->resp->fifo_info'
too small (10 vs 42)

Is it fine and safe to copy always the 42 bytes? I suspect that we should only
copy the number of lost events, total_lost , not always the maximum (16). Or the
EC is always sending the full array (16 bytes)?

Thanks,
Enric


^ permalink raw reply	[flat|nested] 15+ messages in thread

* Re: [PATCH v6 01/11] platform: chrome: sensorhub: Add FIFO support
  2020-03-25 16:28   ` Enric Balletbo i Serra
@ 2020-03-26  8:56     ` Gwendal Grignou
  0 siblings, 0 replies; 15+ messages in thread
From: Gwendal Grignou @ 2020-03-26  8:56 UTC (permalink / raw)
  To: Enric Balletbo i Serra
  Cc: Benson Leung, Jonathan Cameron, linux-iio, linux-kernel

On Wed, Mar 25, 2020 at 9:28 AM Enric Balletbo i Serra
<enric.balletbo@collabora.com> wrote:
>
> Hi Gwendal,
>
> Many thanks for sending this series upstream. Just one comment, other than that
> looks good to me.
>
> On 24/3/20 21:27, Gwendal Grignou wrote:
> > cros_ec_sensorhub registers a listener and query motion sense FIFO,
> > spread to iio sensors registers.
> >
> > To test, we can use libiio:
> > iiod&
> > iio_readdev -u ip:localhost -T 10000 -s 25 -b 16 cros-ec-gyro | od -x
> >
> > Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
> > Signed-off-by: Gwendal Grignou <gwendal@chromium.org>
>
> [snip]
>
> > +/**
> > + * cros_ec_sensorhub_ring_handler() - The trigger handler function
> > + *
> > + * @sensorhub: Sensor Hub object.
> > + *
> > + * Called by the notifier, process the EC sensor FIFO queue.
> > + */
> > +static void cros_ec_sensorhub_ring_handler(struct cros_ec_sensorhub *sensorhub)
> > +{
> > +     struct cros_ec_fifo_info *fifo_info = &sensorhub->fifo_info;
> > +     struct cros_ec_dev *ec = sensorhub->ec;
> > +     ktime_t fifo_timestamp, current_timestamp;
> > +     int i, j, number_data, ret;
> > +     unsigned long sensor_mask = 0;
> > +     struct ec_response_motion_sensor_data *in;
> > +     struct cros_ec_sensors_ring_sample *out, *last_out;
> > +
> > +     mutex_lock(&sensorhub->cmd_lock);
> > +
> > +     /* Get FIFO information if there are lost vectors. */
> > +     if (fifo_info->info.total_lost) {
> > +             /* Need to retrieve the number of lost vectors per sensor */
> > +             sensorhub->params->cmd = MOTIONSENSE_CMD_FIFO_INFO;
> > +             sensorhub->msg->outsize = 1;
> > +             sensorhub->msg->insize =
> > +                     sizeof(struct ec_response_motion_sense_fifo_info) +
> > +                     sizeof(u16) * CROS_EC_SENSOR_MAX;
> > +
> > +             if (cros_ec_cmd_xfer_status(ec->ec_dev, sensorhub->msg) < 0)
> > +                     goto error;
> > +
> > +             memcpy(fifo_info, &sensorhub->resp->fifo_info,
> > +                    sizeof(*fifo_info));
> > +
>
> Smatch is reporting:
Which version of smatch are you using? I am using
v0.5.0-6279-g2f013029 and the problem is not reported.
>
> cros_ec_sensorhub_ring_handler() error: memcpy() '&sensorhub->resp->fifo_info'
> too small (10 vs 42)
>
> Is it fine and safe to copy always the 42 bytes? I suspect that we should only
> copy the number of lost events, total_lost , not always the maximum (16). Or the
> EC is always sending the full array (16 bytes)?
EC will not fill the 42 bytes if it has less than 16 sensors. It is
safe because we are not looking at the bytes we don't need, but it is
not clean.
Working on a new patch set where I remove the CROS_EC_SENSOR_MAX
constant and dynamically allocate the data I need based on the number
of sensors.
>
> Thanks,
> Enric
>

^ permalink raw reply	[flat|nested] 15+ messages in thread

end of thread, back to index

Thread overview: 15+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2020-03-24 20:27 [PATCH v6 00/11] Cros EC sensor hub FIFO support Gwendal Grignou
2020-03-24 20:27 ` [PATCH v6 01/11] platform: chrome: sensorhub: Add " Gwendal Grignou
2020-03-25 16:28   ` Enric Balletbo i Serra
2020-03-26  8:56     ` Gwendal Grignou
2020-03-24 20:27 ` [PATCH v6 02/11] platform: chrome: sensorhub: Add code to spread timestmap Gwendal Grignou
2020-03-24 20:27 ` [PATCH v6 03/11] platform: chrome: sensorhub: Add median filter Gwendal Grignou
2020-03-24 20:27 ` [PATCH v6 04/11] iio: cros_ec: Move function description to .c file Gwendal Grignou
2020-03-24 20:27 ` [PATCH v6 05/11] iio: expose iio_device_set_clock Gwendal Grignou
2020-03-24 20:27 ` [PATCH v6 06/11] iio: cros_ec: Register to cros_ec_sensorhub when EC supports FIFO Gwendal Grignou
2020-03-24 20:27 ` [PATCH v6 07/11] iio: cros_ec: Remove pm function Gwendal Grignou
2020-03-24 20:27 ` [PATCH v6 08/11] iio: cros_ec: Expose hwfifo_timeout Gwendal Grignou
2020-03-24 20:27 ` [PATCH v6 09/11] iio: cros_ec: Report hwfifo_watermark_max Gwendal Grignou
2020-03-24 20:27 ` [PATCH v6 10/11] iio: cros_ec: Use Hertz as unit for sampling frequency Gwendal Grignou
2020-03-24 20:27 ` [PATCH v6 11/11] iio: cros_ec: flush as hwfifo attribute Gwendal Grignou
2020-03-25 15:59 ` [PATCH v6 00/11] Cros EC sensor hub FIFO support Andy Shevchenko

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