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2016-07-02iio: st_sensors: harden interrupt handlingLinus Walleij1-0/+2
Leonard Crestez observed the following phenomenon: when using hard interrupt triggers (the DRDY line coming out of an ST sensor) sometimes a new value would arrive while reading the previous value, due to latencies in the system. We discovered that the ST hardware as far as can be observed is designed for level interrupts: the DRDY line will be held asserted as long as there are new values coming. The interrupt handler should be re-entered until we're out of values to handle from the sensor. If interrupts were handled as occurring on the edges (usually low-to-high) new values could appear and the line be held asserted after that, and these values would be missed, the interrupt handler would also lock up as new data was available, but as no new edges occurs on the DRDY signal, nothing happens: the edge detector only detects edges. To counter this, do the following: - Accept interrupt lines to be flagged as level interrupts using IRQF_TRIGGER_HIGH and IRQF_TRIGGER_LOW. If the line is marked like this (in the device tree node or ACPI table or similar) it will be utilized as a level IRQ. We mark the line with IRQF_ONESHOT and mask the IRQ while processing a sample, then the top half will be entered again if new values are available. - If we are flagged as using edge interrupts with IRQF_TRIGGER_RISING or IRQF_TRIGGER_FALLING: remove IRQF_ONESHOT so that the interrupt line is not masked while running the thread part of the interrupt. This way we will never miss an interrupt, then introduce a loop that polls the data ready registers repeatedly until no new samples are available, then exit the interrupt handler. This way we know no new values are available when the interrupt handler exits and new (edge) interrupts will be triggered when data arrives. Take some extra care to update the timestamp in the poll loop if this happens. The timestamp will not be 100% perfect, but it will at least be closer to the actual events. Usually the extra poll loop will handle the new samples, but once in a blue moon, we get a new IRQ while exiting the loop, before returning from the thread IRQ bottom half with IRQ_HANDLED. On these rare occasions, the removal of IRQF_ONESHOT means the interrupt will immediately fire again. - If no interrupt type is indicated from the DT/ACPI, choose IRQF_TRIGGER_RISING as default, as this is necessary for legacy boards. Tested successfully on the LIS331DL and L3G4200D by setting sampling frequency to 400Hz/800Hz and stressing the system: extra reads in the threaded interrupt handler occurs. Cc: Giuseppe Barba <giuseppe.barba@st.com> Cc: Denis Ciocca <denis.ciocca@st.com> Tested-by: Crestez Dan Leonard <cdleonard@gmail.com> Reported-by: Crestez Dan Leonard <cdleonard@gmail.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org> Signed-off-by: Jonathan Cameron <jic23@kernel.org>
2016-06-20Merge 4.7-rc4 into staging-nextGreg Kroah-Hartman1-1/+8
We want the fixes in here, and we can resolve a merge issue in drivers/iio/industrialio-trigger.c Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-05-29iio: st_sensors: switch to a threaded interruptLinus Walleij1-1/+8
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>
2016-05-29iio:st_sensors: fix power regulator usageGregor Boirie1-1/+1
Ensure failure to enable power regulators is properly handled. Signed-off-by: Gregor Boirie <gregor.boirie@parrot.com> Signed-off-by: Jonathan Cameron <jic23@kernel.org>
2016-05-29iio:st_sensors: unexport st_sensors_get_buffer_elementGregor Boirie1-2/+0
Remove st_sensors_get_buffer_element symbol export since not explicitly used outside of st_sensors driver. Signed-off-by: Gregor Boirie <gregor.boirie@parrot.com> Signed-off-by: Jonathan Cameron <jic23@kernel.org>
2016-04-19iio: st_sensors: support open drain modeLinus Walleij1-0/+6
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 <giuseppe.barba@st.com> Cc: Denis Ciocca <denis.ciocca@st.com> Acked-by: Rob Herring <rob@kernel.org> Signed-off-by: Linus Walleij <linus.walleij@linaro.org> Signed-off-by: Jonathan Cameron <jic23@kernel.org>
2016-04-19iio: st_sensors: verify interrupt event to statusLinus Walleij1-0/+3
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 <giuseppe.barba@st.com> Cc: Denis Ciocca <denis.ciocca@st.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org> Signed-off-by: Jonathan Cameron <jic23@kernel.org>
2016-01-10iio: st_sensors: support active-low interruptsLinus Walleij1-0/+4
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 <giuseppe.barba@st.com> Cc: Denis Ciocca <denis.ciocca@st.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org> Signed-off-by: Jonathan Cameron <jic23@kernel.org>
2015-08-16iio: st_sensors: add debugfs register read hookLinus Walleij1-0/+4
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 <linus.walleij@linaro.org> Acked-by: Denis Ciocca <denis.ciocca@st.com> Signed-off-by: Jonathan Cameron <jic23@kernel.org>
2015-07-23iio: st-sensors: add configuration for WhoAmI addressGiuseppe Barba1-0/+2
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 <giuseppe.barba@st.com> Reviewed-by: Denis Ciocca <denis.ciocca@st.com> Acked-by: Denis Ciocca <denis.ciocca@st.com> Signed-off-by: Jonathan Cameron <jic23@kernel.org>
2015-01-29iio: common: ssp_sensors: Add sensorhub driverKarol Wrona1-0/+82
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 <k.wrona@samsung.com> Acked-by: Kyungmin Park <kyungmin.park@samsung.com> Signed-off-by: Jonathan Cameron <jic23@kernel.org>
2014-10-04iio:imu: changed structure name from st_sensors to st_sensor_settingsDenis CIOCCA1-5/+5
This patch change structure name and related variables names. Signed-off-by: Denis Ciocca <denis.ciocca@st.com> Signed-off-by: Jonathan Cameron <jic23@kernel.org>
2014-07-12iio: st_sensors: add devicetree probing supportLinus Walleij1-0/+11
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 <lee.jones@linaro.org> Cc: Denis CIOCCA <denis.ciocca@st.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org> Signed-off-by: Jonathan Cameron <jic23@kernel.org>
2014-07-07iio:st sensors: remove custom sampling frequence attribute in favour of core ↵Jonathan Cameron1-11/+1
support. This allows in kernel client drivers to access this Signed-off-by: Jonathan Cameron <jic23@kernel.org> Cc: Denis Ciocca <denis.ciocca@st.com> Reviewed-by: Hartmut Knaack <knaack.h@gmx.de>
2014-04-26iio: st_sensors: move regulator retrieveal to coreLinus Walleij1-0/+4
Currently the pressure sensor has code to retrieve and enable two regulators for Vdd and Vdd IO, but actually these voltage inputs are found on all of these ST sensors, so move the regulator handling to the core and make sure all the ST sensors call these functions on probe() and remove() to enable/disable power. Here also mover over to obtaining the regulator from the *parent* device of the IIO device, as the IIO device is created on-the-fly in this very subsystem it very unlikely evert have any regulators attached to it whatsoever. It is much more likely that the parent is a platform device, possibly instantiated from a device tree, which in turn have Vdd and Vdd IO supplied assigned to it. Cc: Lee Jones <lee.jones@linaro.org> Cc: Denis CIOCCA <denis.ciocca@st.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org> Signed-off-by: Jonathan Cameron <jic23@kernel.org>
2013-09-23iio: pressure-core: st: Provide support for the Vdd_IO power supplyLee Jones1-0/+2
The power to some of the sensors are controlled by regulators. In most cases these are 'always on', but if not they will fail to work until the regulator is enabled using the relevant APIs. This patch allows for the Vdd_IO power supply to be specified by either platform data or Device Tree. Signed-off-by: Lee Jones <lee.jones@linaro.org> Signed-off-by: Jonathan Cameron <jic23@kernel.org>
2013-09-23iio: pressure-core: st: Provide support for the Vdd power supplyLee Jones1-0/+3
The power to some of the sensors are controlled by regulators. In most cases these are 'always on', but if not they will fail to work until the regulator is enabled using the relevant APIs. This patch allows for the Vdd power supply to be specified by either platform data or Device Tree. Signed-off-by: Lee Jones <lee.jones@linaro.org> Signed-off-by: Jonathan Cameron <jic23@kernel.org>
2013-09-15iio: pressure-core: st: Allow for number of channels to varyLee Jones1-0/+1
At the moment the number of channels specified is dictated by the first sensor supported by the driver. As we add support for more sensors this is likely to vary. Instead of using the ARRAY_SIZE() of the LPS331AP's channel specifier we'll use a new adaptable 'struct st_sensors' element instead. Signed-off-by: Lee Jones <lee.jones@linaro.org> Acked-by: Denis Ciocca <denis.ciocca@st.com> Signed-off-by: Jonathan Cameron <jic23@kernel.org>
2013-08-03iio: Added ST-sensors platform data to select the DRDY interrupt pinDenis CIOCCA1-3/+11
This patch add support to redirect the DRDY interrupt on INT1 or INT2 on accelerometer and pressure sensors. Signed-off-by: Denis Ciocca <denis.ciocca@st.com> Signed-off-by: Jonathan Cameron <jic23@kernel.org>
2013-06-05iio:common: Removed stuff macros, added num_data_channels on st_sensors ↵Denis CIOCCA1-2/+2
struct and added support on one-shot sysfs reads to 3 byte channel This patch introduce num_data_channels variable on st_sensors struct to manage different type of channels (size or number) in st_sensors_get_buffer_element function. Removed ST_SENSORS_NUMBER_DATA_CHANNELS and ST_SENSORS_BYTE_FOR_CHANNEL and used struct iio_chan_spec const *ch to catch data. Added 3 byte channel data support on one-shot reads. Signed-off-by: Denis Ciocca <denis.ciocca@st.com> Signed-off-by: Jonathan Cameron <jic23@kernel.org>
2013-06-04iio:common: ST_SENSORS_LSM_CHANNELS macro changedDenis CIOCCA1-11/+9
Signed-off-by: Denis Ciocca <denis.ciocca@st.com> Signed-off-by: Jonathan Cameron <jic23@kernel.org>
2013-03-25Merge tag 'iio-for-3.10a' of ↵Greg Kroah-Hartman1-2/+3
git://git.kernel.org/pub/scm/linux/kernel/git/jic23/iio into staging-next Jonathan writes: First set of IIO new drivers and cleanup for the 3.10 cycle. New stuff 1) Add OF support for specifying mappings between iio devices and their in kernel consumers. 2) Driver for AD7923 (extra functionality and support for ad7904, ad7914 and ad7924 added later in series) 3) Driver for Exynos adc (dt suppor for phy added later in series). 4) Make iio_push_event save IRQ context - necessary if it is to be used within an interrupt handler. Users of this functionality to follow. 5) For iio use the device tree node name to provide the hwmon name attribute if available. Removal and moves out of staging 1) Drop the adt7410 driver from IIO now that there is a hmwon driver with equivalent support. This device is very much targeted at hardware monitoring so hwmon is a more appropriate host for the driver. 2) Move iio_hwmon driver to drivers/hwmon. Cleanups 1) Minor cleanup in ST common library. 2) Large set of patches to break the info_mask element which previously used odd and even bits to specify if a channel attribute was either shared across similar channels or specific to only one. Now we have two bitmaps, one for those parameters that are specific to this channel and one for those shared by all channels with the same type as this one. This has no effect on the userspace abi. It simplifies the core code and provides more space for new channel parameters. It has been on the todo list for a long time! Conflicts: drivers/iio/dac/ad5064.c
2013-03-17iio:st_sensors move to info_mask_(shared_by_type/separate)Jonathan Cameron1-2/+3
The original info_mask is going away in favour of the broken out versions. Signed-off-by: Jonathan Cameron <jic23@kernel.org> Acked-by: Denis Ciocca <denis.ciocca@st.com>
2013-03-02iio: Fix build error seen if IIO_TRIGGER is defined but IIO_BUFFER is notGuenter Roeck1-3/+6
If CONFIG_IIO_TRIGGER is defined but CONFIG_IIO_BUFFER is not, the following build error is seen. drivers/iio/common/st_sensors/st_sensors_trigger.c:21:5: error: redefinition of ‘st_sensors_allocate_trigger’ In file included from drivers/iio/common/st_sensors/st_sensors_trigger.c:18:0: include/linux/iio/common/st_sensors.h:239:19: note: previous definition of ‘st_sensors_allocate_trigger’ was here drivers/iio/common/st_sensors/st_sensors_trigger.c:65:6: error: redefinition of ‘st_sensors_deallocate_trigger’ In file included from drivers/iio/common/st_sensors/st_sensors_trigger.c:18:0: include/linux/iio/common/st_sensors.h:244:20: note: previous definition of ‘st_sensors_deallocate_trigger’ was here This occurs because st_sensors_deallocate_trigger is built if CONFIG_IIO_TRIGGER is defined, but the dummy function is compiled if CONFIG_IIO_BUFFER is defined. Signed-off-by: Guenter Roeck <linux@roeck-us.net> Acked-by: Denis Ciocca <denis.ciocca@st.com> Signed-off-by: Jonathan Cameron <jic23@kernel.org>
2013-02-09iio:common: added allocate and deallocate trigger functions when trigger is ↵Denis CIOCCA1-0/+10
disabled. This patch resolve a bugfix when driver is compiled without trigger. Signed-off-by: Denis Ciocca <denis.ciocca@st.com> Reported-by: Randy Dunlap <rdunlap@infradead.org> Signed-off-by: Jonathan Cameron <jic23@kernel.org>
2013-02-02iio:common: removed unused functions outside st_sensors libraryDenis CIOCCA1-4/+0
This patch remove st_sensors_get_sampling_frequency_avl and st_sensors_get_scale_avl functions used only in st_sensors_sysfs_sampling_frequency_avail and st_sensors_sysfs_scale_avail sysfs functions. Signed-off-by: Denis Ciocca <denis.ciocca@st.com> Signed-off-by: Jonathan Cameron <jic23@kernel.org>
2013-01-31iio:common: Add STMicroelectronics common libraryDenis Ciocca3-0/+314
This patch add a generic library for STMicroelectronics 3-axis sensors. 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>