Commit Graph

8 Commits

Author SHA1 Message Date
Gwendal Grignou
7f4784f188 platform/chrome: cros_ec_sensorhub: Simplify legacy timestamp spreading
On some machines (nami), interrupt latency cause samples to appear
to be from the future and are pegged to the current time.
We would see samples with this pattern:

[t, t + ~5ms, t + ~10ms, t + ~10ms + 100us, t + ~10ms + 200us],
                             (current now)      (current now)
(t is the last timestamp time)

Last 2 samples would be barely spread, causing applications to
complain.

We now spread the entire sequence. This is not great: in the example
the sensor was supposed to send samples every 5ms, it now appears to
send one every 2.5ms, but it is slightly closer to reality:

sampling time in the example above
At sensor level

1             2             3             4            5
+-----5ms-----+-----5ms-----+-----5ms-----+----5ms-----+---> t

Before, at host level
                       1             2             3 4 5
--interrupt delay------+-----5ms-----+-----5ms-----+-+-+---> t

Afer, at host level
                       1       2       3       4       5
--interrupt delay------+-2.5ms-+-2.5ms-+-2.5ms-+-2.5ms-+---> t

Signed-off-by: Gwendal Grignou <gwendal@chromium.org>
Signed-off-by: Enric Balletbo i Serra <enric.balletbo@collabora.com>
2020-07-31 11:52:43 +02:00
Gwendal Grignou
e48bc01ed5 platform/chrome: cros_ec_sensorhub: Fix EC timestamp overflow
EC is using 32 bit timestamps (us), and before converting it to 64bit
they were not casted, so it would overflow every 4s.
Regular overflow every ~70 minutes was not taken into account either.

Signed-off-by: Gwendal Grignou <gwendal@chromium.org>
Signed-off-by: Enric Balletbo i Serra <enric.balletbo@collabora.com>
2020-06-30 16:35:22 +02:00
Gwendal Grignou
b31d1d2b1c platform/chrome: cros_ec_sensorhub: Allocate sensorhub resource before claiming sensors
Allocate callbacks array before enumerating the sensors: The probe routine
for these sensors (for instance cros_ec_sensors_probe) can be called
within the sensorhub probe routine (cros_ec_sensors_probe())

Fixes: 145d59baff ("platform/chrome: cros_ec_sensorhub: Add FIFO support")
Signed-off-by: Gwendal Grignou <gwendal@chromium.org>
Reported-by: Douglas Anderson <dianders@chromium.org>
Tested-by: Douglas Anderson <dianders@chromium.org>
Signed-off-by: Enric Balletbo i Serra <enric.balletbo@collabora.com>
2020-04-29 23:17:45 +02:00
Christophe JAILLET
538b8471fe platform/chrome: cros_ec_sensorhub: Add missing '\n' in log messages
Message logged by 'dev_xxx()' or 'pr_xxx()' should end with a '\n'.

Fixes: 145d59baff ("platform/chrome: cros_ec_sensorhub: Add FIFO support")
Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Signed-off-by: Enric Balletbo i Serra <enric.balletbo@collabora.com>
2020-04-13 16:31:33 +02:00
Dan Carpenter
5b69c23799 platform/chrome: cros_ec_sensorhub: Off by one in cros_sensorhub_send_sample()
The sensorhub->push_data[] array has sensorhub->sensor_num elements.
It's allocated in cros_ec_sensorhub_ring_add().  So the > should be >=
to prevent a read one element beyond the end of the array.

Fixes: 145d59baff ("platform/chrome: cros_ec_sensorhub: Add FIFO support")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Reviewed-by: Guenter Roeck <groeck@chromium.org>
Signed-off-by: Enric Balletbo i Serra <enric.balletbo@collabora.com>
2020-04-13 08:09:27 +02:00
Gwendal Grignou
93fe48a585 platform/chrome: cros_ec_sensorhub: Add median filter
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.

Signed-off-by: Gwendal Grignou <gwendal@chromium.org>
Acked-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Acked-by: Lee Jones <lee.jones@linaro.org>
Acked-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: Enric Balletbo i Serra <enric.balletbo@collabora.com>
2020-03-28 22:04:32 +01:00
Gwendal Grignou
b9b05664eb platform/chrome: cros_ec_sensorhub: Add code to spread timestmap
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       |
+-----------+

Signed-off-by: Gwendal Grignou <gwendal@chromium.org>
Acked-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Acked-by: Lee Jones <lee.jones@linaro.org>
Acked-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: Enric Balletbo i Serra <enric.balletbo@collabora.com>
2020-03-28 22:04:32 +01:00
Gwendal Grignou
145d59baff platform/chrome: cros_ec_sensorhub: Add FIFO support
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

Signed-off-by: Gwendal Grignou <gwendal@chromium.org>
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Acked-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: Enric Balletbo i Serra <enric.balletbo@collabora.com>
2020-03-28 22:04:32 +01:00