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path: root/drivers/iio/accel/st_accel_buffer.c
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2016-05-29iio: st_sensors: switch to a threaded interruptLinus Walleij
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>
2013-10-16iio:st_accel: Drop redundant call to iio_sw_buffer_preenable()Lars-Peter Clausen
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>
2013-03-25iio:trigger: Introduce iio_tigger_{set,get}_drvdataLars-Peter Clausen
Introduce iio_tigger_{set,get}_drvdata which allows to attach driver specific data to a trigger. The functions wrap access to the triggers private_data field and all current users are updated to use iio_tigger_{set,get}_drvdata instead of directly accessing the private_data field. This is the first step towards removing the private_data field from the iio_trigger struct. The following coccinelle script has been used to update the drivers: <smpl> @@ struct iio_trigger *trigger; expression priv; @@ -trigger->private_data = priv +iio_trigger_set_drv_data(trigger, priv) @@ struct iio_trigger *trigger; @@ -trigger->private_data +iio_trigger_get_drv_data(trigger) </smpl> Signed-off-by: Lars-Peter Clausen <lars@metafoo.de> Signed-off-by: Jonathan Cameron <jic23@kernel.org>
2013-01-31iio:accel: Add STMicroelectronics accelerometers driverDenis Ciocca
This patch adds a generic accelerometer driver for STMicroelectronics accelerometers, currently it supports: LSM303DLH, LSM303DLHC, LIS3DH, LSM330D, LSM330DL, LSM330DLC, LIS331DLH, LSM303DL, LSM303DLM, LSM330. Signed-off-by: Denis Ciocca <denis.ciocca@st.com> Reviewed-by: Lars-Peter Clausen <lars@metafoo.de> Signed-off-by: Jonathan Cameron <jic23@kernel.org>