Commit Graph

9 Commits

Author SHA1 Message Date
Denis Ciocca
e031d5f558 iio:st_sensors: remove buffer allocation at each buffer enable
This patch is removing the buffer allocation at each buffer enable.
We just allocate enough memory in the main structure during probe
to cover maximum size needed (that anyway is pretty small) [16bytes].

Signed-off-by: Denis Ciocca <denis.ciocca@st.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
2019-08-11 09:26:04 +01:00
Denis Ciocca
6ee19af415 iio:magn: preenable/postenable/predisable fixup for ST magn buffer
This patch is trying to cleanup for good the buffers operation functions.
Let's rename the goto label using operation to perform and not
where it fails.

Not stable material as not fixing a 'bug' but rather bringing the
driver in line with general 'patterns' to allow a subsystem wide
cleanup.

Signed-off-by: Denis Ciocca <denis.ciocca@st.com>
Reviewed-by: Alexandru Ardelean <alexandru.ardelean@analog.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
2019-08-05 15:49:18 +01:00
Denis Ciocca
062809ef77 iio: make st_sensors drivers use regmap
This patch is meant to replace the i2c/spi transfer functions with
regmap. SPI framework requires DMA safe buffers so let's add GFP_DMA
flag for memory allocation used by bulk_read functions.

Signed-off-by: Denis Ciocca <denis.ciocca@st.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
2019-07-27 22:52:06 +01:00
Thomas Gleixner
fda8d26e61 treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 177
Based on 1 normalized pattern(s):

  licensed under the gpl 2

extracted by the scancode license scanner the SPDX license identifier

  GPL-2.0-only

has been chosen to replace the boilerplate/reference in 135 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Allison Randal <allison@lohutok.net>
Reviewed-by: Richard Fontana <rfontana@redhat.com>
Reviewed-by: Alexios Zavras <alexios.zavras@intel.com>
Reviewed-by: Steve Winslow <swinslow@gmail.com>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190528170026.071193225@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-30 11:29:19 -07:00
Martin Kelly
fe5192ac81 iio:st_magn: Fix enable device after trigger
Currently, we enable the device before we enable the device trigger. At
high frequencies, this can cause interrupts that don't yet have a poll
function associated with them and are thus treated as spurious. At high
frequencies with level interrupts, this can even cause an interrupt storm
of repeated spurious interrupts (~100,000 on my Beagleboard with the
LSM9DS1 magnetometer). If these repeat too much, the interrupt will get
disabled and the device will stop functioning.

To prevent these problems, enable the device prior to enabling the device
trigger, and disable the divec prior to disabling the trigger. This means
there's no window of time during which the device creates interrupts but we
have no trigger to answer them.

Fixes: 90efe05562 ("iio: st_sensors: harden interrupt handling")
Signed-off-by: Martin Kelly <martin@martingkelly.com>
Tested-by: Denis Ciocca <denis.ciocca@st.com>
Cc: <Stable@vger.kernel.org>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
2018-11-03 11:24:07 +00:00
Linus Walleij
65925b65ed iio: st_sensors: switch to a threaded interrupt
commit 98ad8b41f58dff6b30713d7f09ae3834b8df7ded
("iio: st_sensors: verify interrupt event to status") caused
a regression when reading ST sensors from a HRTimer trigger
rather than the intrinsic interrupts: the HRTimer may
trigger faster than the sensor provides new values, and
as the check against new values available as a cause of
the interrupt trigger was done in the poll function,
this would bail out of the HRTimer interrupt with
IRQ_NONE.

So clearly we need to only check the new values available
from the proper interrupt handler and not from the poll
function, which should rather just read the raw values
from the registers, put them into the buffer and be happy.

To achieve this: switch the ST Sensors over to using a true
threaded interrupt handler.

In the interrupt thread, check if new values are available,
else yield to the (potential) next device on the same
interrupt line to check the registers. If the interrupt
was ours, proceed to poll the values.

Instead of relying on iio_trigger_generic_data_rdy_poll() as
a top half to wake up the thread that polls the sensor for
new data, have the thread call iio_trigger_poll_chained()
after determining that is is the proper source of the
interrupt. This is modelled on drivers/iio/accel/mma8452.c
which is already using a properly threaded interrupt handler.

In order to get the same precision in timestamps as
previously, where samples would be timestamped in the
poll function pf->timestamp when calling
iio_trigger_generic_data_rdy_poll() we introduce a
local timestamp in the sensor data, set it in the top half
(fastpath) of the interrupt handler and provide that to the
core when calling iio_push_to_buffers_with_timestamp().

Additionally: if the active scanmask is not set for the
sensor no IRQs should be enabled and we need to bail out
with IRQ_NONE. This can happen if spurious IRQs fire when
installing the threaded interrupt handler.

Tested with hard interrupt triggers on LIS331DL, then also
tested with hrtimers on the same sensor by creating a 75Hz
HRTimer and using it to poll the sensor.

Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Cc: Giuseppe Barba <giuseppe.barba@st.com>
Cc: Denis Ciocca <denis.ciocca@st.com>
Reported-by: Crestez Dan Leonard <cdleonard@gmail.com>
Tested-by: Crestez Dan Leonard <cdleonard@gmail.com>
Tested-by: Jonathan Cameron <jic23@kernel.org>
Fixes: 97865fe413 ("iio: st_sensors: verify interrupt event to status")
Signed-off-by: Jonathan Cameron <jic23@kernel.org>
2016-05-29 20:21:41 +01:00
Giuseppe Barba
74f5683f35 iio: st_magn: Add irq trigger handling
Add irq trigger handling for magnetometer also

Signed-off-by: Giuseppe Barba <giuseppe.barba@st.com>
Acked-by: Denis Ciocca <denis.ciocca@st.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>
2015-07-23 20:43:13 +01:00
Lars-Peter Clausen
bbc1751d24 iio:st_magn: Remove redundant call to iio_sw_buffer_preenable().
The equivalent of iio_sw_buffer_preenable() is now done in the IIO buffer core,
so there is no need to do this from the driver anymore.

Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Cc: Denis Ciocca <denis.ciocca@st.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>
2013-10-16 19:13:50 +01:00
Denis Ciocca
872e79add7 iio:magnetometer: Add STMicroelectronics magnetometers driver
This patch adds a generic magnetometer driver for STMicroelectronics
magnetometers, currently it supports:
LSM303DLHC, LSM303DLM, LIS3MDL.

Signed-off-by: Denis Ciocca <denis.ciocca@st.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>
2013-01-31 17:56:43 +00:00