talos-obmc-linux/include/linux/iio/common, branch v4.7

iio: st_sensors: switch to a threaded interrupt

2016-05-29T19:21:41+00:00

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 Cc: Giuseppe Barba Cc: Denis Ciocca Reported-by: Crestez Dan Leonard Tested-by: Crestez Dan Leonard Tested-by: Jonathan Cameron Fixes: 97865fe41322 ("iio: st_sensors: verify interrupt event to status") Signed-off-by: Jonathan Cameron

iio: st_sensors: support open drain mode

2016-04-19T18:58:13+00:00

Some types of ST Sensors can be connected to the same IRQ line as other peripherals using open drain. Add a device tree binding and a sensor data property to flip the right bit in the interrupt control register to enable open drain mode on the INT line. If the line is set to be open drain, also tag on IRQF_SHARED to the IRQ flags when requesting the interrupt, as the whole point of using open drain interrupt lines is to share them with more than one peripheral (wire-or). Cc: devicetree@vger.kernel.org Cc: Giuseppe Barba Cc: Denis Ciocca Acked-by: Rob Herring Signed-off-by: Linus Walleij Signed-off-by: Jonathan Cameron

iio: st_sensors: verify interrupt event to status

2016-04-19T18:58:12+00:00

This makes all ST sensor drivers check that they actually have new data available for the requested channel(s) before claiming an IRQ, by reading the status register (which is conveniently the same for all ST sensors) and check that the channel has new data before proceeding to read it and fill the buffer. This way sensors can share an interrupt line: it can be flaged as shared and then the sensor that did not fire will return NO_IRQ, and the sensor that fired will handle the IRQ and return IRQ_HANDLED. Cc: Giuseppe Barba Cc: Denis Ciocca Signed-off-by: Linus Walleij Signed-off-by: Jonathan Cameron

iio: st_sensors: support active-low interrupts

2016-01-10T12:35:32+00:00

Most ST MEMS Sensors that support interrupts can also handle sending an active low interrupt, i.e. going from high to low on data ready (or other interrupt) and thus triggering on a falling edge to the interrupt controller. Set up logic to inspect the interrupt line we get for a sensor: if it is triggering on rising edge, leave everything alone, but if it triggers on falling edges, set up active low, and if unsupported configurations appear: warn with errors and reconfigure the interrupt to a rising edge, which all interrupt generating sensors support. Create a local header for st_sensors_core.h to share functions between the sensor core and the trigger setup code. Cc: Giuseppe Barba Cc: Denis Ciocca Signed-off-by: Linus Walleij Signed-off-by: Jonathan Cameron

iio: st_sensors: add debugfs register read hook

2015-08-16T09:51:25+00:00

This adds a debugfs hook to read/write registers in the ST sensors using debugfs. Proved to be awesome help when trying to debug why IRQs do not arrive. Signed-off-by: Linus Walleij Acked-by: Denis Ciocca Signed-off-by: Jonathan Cameron

iio: st-sensors: add configuration for WhoAmI address

2015-07-23T19:43:04+00:00

This patch permits to configure the WhoAmI register address because some device could have not a standard address for this register. Signed-off-by: Giuseppe Barba Reviewed-by: Denis Ciocca Acked-by: Denis Ciocca Signed-off-by: Jonathan Cameron

iio: common: ssp_sensors: Add sensorhub driver

2015-01-29T18:49:05+00:00

Sensorhub is MCU dedicated to collect data and manage several sensors. Sensorhub is a spi device which provides a layer for IIO devices. It provides some data parsing and common mechanism for sensorhub sensors. Adds common sensorhub library for sensorhub driver and iio drivers which uses sensorhub MCU to communicate with sensors. Signed-off-by: Karol Wrona Acked-by: Kyungmin Park Signed-off-by: Jonathan Cameron

iio:imu: changed structure name from st_sensors to st_sensor_settings

2014-10-04T10:23:13+00:00

This patch change structure name and related variables names. Signed-off-by: Denis Ciocca Signed-off-by: Jonathan Cameron

iio: st_sensors: add devicetree probing support

2014-07-11T20:09:49+00:00

The I2C devices that make up the STMicroelectronics MEMS sensors may be sneakily enabled by cleverly giving the device node the same name as a string match from the platform device ID table. However the right method is to use the compatible string. On detection, the ST sensors use the ID string to probe and instatiate the right sensor driver, so pass the kernel-internal ID string in the .data field of the OF match table, and set the I2C client name to this name when a compatible match is used. This avoids having misc Linux-specific strings floating around in the device tree. Cc: Lee Jones Cc: Denis CIOCCA Signed-off-by: Linus Walleij Signed-off-by: Jonathan Cameron

iio:st sensors: remove custom sampling frequence attribute in favour of core support.

2014-07-07T08:39:57+00:00

This allows in kernel client drivers to access this Signed-off-by: Jonathan Cameron Cc: Denis Ciocca Reviewed-by: Hartmut Knaack