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* iio:st_magn: Fix enable device after triggerMartin Kelly2018-12-051-9/+3Star
| | | | | | | | | | | | | | | | | | | | | | | | | commit fe5192ac81ad0d4dfe1395d11f393f0513c15f7f upstream. 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: 90efe055629 ("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> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* iio: st_sensors: switch to a threaded interruptLinus Walleij2016-05-291-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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: 97865fe41322 ("iio: st_sensors: verify interrupt event to status") Signed-off-by: Jonathan Cameron <jic23@kernel.org>
* iio: st_magn: Add irq trigger handlingGiuseppe Barba2015-07-231-0/+7
| | | | | | | | 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>
* iio:st_magn: Remove redundant call to iio_sw_buffer_preenable().Lars-Peter Clausen2013-10-161-10/+1Star
| | | | | | | | | 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>
* iio:magnetometer: Add STMicroelectronics magnetometers driverDenis Ciocca2013-01-311-0/+98
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>