From: Andy Shevchenko <andy.shevchenko@gmail.com>
To: Gwendal Grignou <gwendal@chromium.org>
Cc: Benson Leung <bleung@chromium.org>,
Enric Balletbo i Serra <enric.balletbo@collabora.com>,
Jonathan Cameron <Jonathan.Cameron@huawei.com>,
linux-iio <linux-iio@vger.kernel.org>,
Linux Kernel Mailing List <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH v6 00/11] Cros EC sensor hub FIFO support
Date: Wed, 25 Mar 2020 17:59:00 +0200 [thread overview]
Message-ID: <CAHp75Vd+46fdKZXuFj0sAhXw9cfN+5SFW3dFZh+YsLFNiiGDWQ@mail.gmail.com> (raw)
In-Reply-To: <20200324202736.243314-1-gwendal@chromium.org>
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
prev parent reply other threads:[~2020-03-25 15:59 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
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 ` Andy Shevchenko [this message]
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=CAHp75Vd+46fdKZXuFj0sAhXw9cfN+5SFW3dFZh+YsLFNiiGDWQ@mail.gmail.com \
--to=andy.shevchenko@gmail.com \
--cc=Jonathan.Cameron@huawei.com \
--cc=bleung@chromium.org \
--cc=enric.balletbo@collabora.com \
--cc=gwendal@chromium.org \
--cc=linux-iio@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).