Re: [PATCH v2 00/18] cros_ec: Add sensorhub driver and FIFO processing*** SUBJECT HERE

From: Jonathan Cameron
Date: Mon Oct 21 2019 - 11:29:18 EST


On Sun, 20 Oct 2019 22:53:45 -0700
Gwendal Grignou <gwendal@xxxxxxxxxxxx> wrote:

Tidy up the title for v3!

> 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 first patch move cros_ec_proto functions documentations into the
> code to prevent rot.
>
> The inext 3 patches add a primitive cros_ec_sensorhub. MFD just have to

next

> register this driver if at least one sensor is presented by the EC.
> cros_ec_sensorhub retrieves more information from the EC to find out
> which sensors are actually present:
> mfd: cros_ec: Add sensor_count and make check_features public
> platform: cros_ec: Add cros_ec_sensor_hub driver
> platform/mfd:iio: cros_ec: Register sensor through sensorhub
>
> The next 3 patches prepare for FIFO support:
> platform: chrome: cros-ec: record event timestamp in the hard irq
> platform: chrome: cros_ec: Do not attempt to register a non-positive
> platform: chrome: cros_ec: handle MKBP more events flag
>
> That last patch fixes a regression that changes event processing.
> Revert the patches that fixed that regression.
>
> The next 3 patches add FIFO support. An interface is added to connect
> the IIO sensors with cros_ec_sensorhub, and filters are needed to spread
> the timestamp when the EC send batches of events and deal with variation
> in interrupt delay.
> platform: chrome: sensorhub: Add FIFO support
> platform: chrome: sensorhub: Add code to spread timestmap
> platform: chrome: sensorhub: Add median filter
>
> The remaining patches update IIO cros_ec drivers:
> The first patch moves cros_ec_sensor_core functions documentation into
> the .c file.
> Then we can use the FIFO function exposed by cros_ec_sensorhub:
> iio: cros_ec: Use triggered buffer only when EC does not support FIFO
>
> The power management functions are not necessary anymore, since we
> shutoff the FIFO from cros_ec_sensorhub:
> iio: cros_ec: Register to cros_ec_sensorhub when EC supports FIFO
>
> Finally, the last 3 patches present sensor information following the IIO
> ABI:
> - Configurable EC timeout to allow batch mode in buffer/hwfifo_timeout,
> in seconds.
> - Hard coded EC FIFO size in buffer/hwfifo_watermark_max
> - Sensor sampling frequency in hertz at sampling_frequency:
> iio: cros_ec: Expose hwfifo_timeout
> iio: cros_ec: Report hwfifo_watermark_max
> iio: cros_ec: Use Hertz as unit for sampling frequency
>
> For testing, libiio test tools can be used:
> A iio device link looks like:
> iio:device1 ->
> ...09:00/GOOG0004:00/cros-ec-dev.6.auto/cros-ec-sensorhub.7.auto/
> cros-ec-accel.15.auto/iio:device1
>
> When FIFO is available, no trigger are presented. Once
> sampling_freqeuncy and hwfifo_timeout are set, sensor events flow
> when listening to /dev/iio:device1:
> echo 12 > sampling_frequency # Set ODR to at least 12Hz
> echo .100 > buffer/hwfifo_timeout # do not wait more than 100ms to
> # to send samples
> iio_readdev -b 2 -T 1000 -s 2 iio:device1 2>/dev/null| od -x
> 0000000 ffd0 2e20 d990 0000 8630 b56c 07ea 0000
> 0000020 ffc0 2e10 d970 0000 877e b56c 07ea 0000
> 0000040`
>
> 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.
>
> This set is built upon the master branch of
> git://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git
>
> Enrico Granata (2):
> platform: chrome: cros_ec: Do not attempt to register a non-positive
> IRQ number
> platform: chrome: cros_ec: handle MKBP more events flag
>
> Gwendal Grignou (16):
> platform: chrome: Put docs with the code
> mfd: cros_ec: Add sensor_count and make check_features public
> platform: cros_ec: Add cros_ec_sensor_hub driver
> platform/mfd:iio: cros_ec: Register sensor through sensorhub
> platform: chrome: cros-ec: record event timestamp in the hard irq
> Revert "Input: cros_ec_keyb - add back missing mask for event_type"
> Revert "Input: cros_ec_keyb: mask out extra flags in event_type"
> 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: 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
>
> drivers/iio/accel/cros_ec_accel_legacy.c | 14 +-
> drivers/iio/common/cros_ec_sensors/Kconfig | 2 +-
> .../cros_ec_sensors/cros_ec_lid_angle.c | 3 +-
> .../common/cros_ec_sensors/cros_ec_sensors.c | 19 +-
> .../cros_ec_sensors/cros_ec_sensors_core.c | 359 +++++--
> drivers/iio/light/cros_ec_light_prox.c | 21 +-
> drivers/iio/pressure/cros_ec_baro.c | 14 +-
> drivers/input/keyboard/cros_ec_keyb.c | 6 +-
> drivers/mfd/cros_ec_dev.c | 235 +----
> drivers/platform/chrome/Kconfig | 12 +
> drivers/platform/chrome/Makefile | 2 +
> drivers/platform/chrome/cros_ec.c | 80 +-
> drivers/platform/chrome/cros_ec_ishtp.c | 25 +-
> drivers/platform/chrome/cros_ec_lpc.c | 17 +-
> drivers/platform/chrome/cros_ec_proto.c | 267 ++++-
> drivers/platform/chrome/cros_ec_rpmsg.c | 23 +-
> drivers/platform/chrome/cros_ec_sensorhub.c | 263 +++++
> .../platform/chrome/cros_ec_sensorhub_ring.c | 973 ++++++++++++++++++
> .../linux/iio/common/cros_ec_sensors_core.h | 106 +-
> include/linux/platform_data/cros_ec_proto.h | 138 +--
> .../linux/platform_data/cros_ec_sensorhub.h | 171 +++
> 21 files changed, 2118 insertions(+), 632 deletions(-)
> create mode 100644 drivers/platform/chrome/cros_ec_sensorhub.c
> create mode 100644 drivers/platform/chrome/cros_ec_sensorhub_ring.c
> create mode 100644 include/linux/platform_data/cros_ec_sensorhub.h
>