Since the buffer is accessed by userspace we can not just free the buffers
memory once we are done with it in kernel space. There might still be open file
descriptors and userspace still might be accessing the buffer. This patch adds
support for reference counting to the IIO buffers. When a buffer is created and
initialized its initial reference count is set to 1. Instead of freeing the
memory of the buffer the buffer's _free() function will drop that reference
again. But only after the last reference to the buffer has been dropped the
buffer the buffer's memory will be freed. The IIO device will take a reference
to its primary buffer. The patch adds a small helper function for this called
iio_device_attach_buffer() which will get a reference to the buffer and assign
the buffer to the IIO device. This function must be used instead of assigning
the buffer to the device by hand. The reference is only dropped once the IIO
device is freed and we can be sure that there are no more open file handles. A
reference to a buffer will also be taken whenever the buffer is active to avoid
the buffer being freed while data is still being send to it.
Signed-off-by: NLars-Peter Clausen <lars@metafoo.de>
Signed-off-by: NJonathan Cameron <jic23@kernel.org>

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: NLee Jones <lee.jones@linaro.org>
Signed-off-by: NJonathan Cameron <jic23@kernel.org>

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: NLee Jones <lee.jones@linaro.org>
Signed-off-by: NJonathan Cameron <jic23@kernel.org>

Drivers using software buffers often store the timestamp in their data buffer
before calling iio_push_to_buffers() with that data buffer. Storing the
timestamp in the buffer usually involves some ugly pointer arithmetic. This
patch adds a new helper function called iio_push_buffers_with_timestamp() which
is similar to iio_push_to_buffers but takes an additional timestamp parameter.
The function will help to hide to uglyness in one central place instead of
exposing it in every driver. If timestamps are enabled for the IIO device
iio_push_buffers_with_timestamp() will store the timestamp as the last element
in buffer, before passing the buffer on to iio_push_buffers(). The buffer needs
large enough to hold the timestamp in this case. If timestamps are disabled
iio_push_buffers_with_timestamp() will behave just like iio_push_buffers().
Signed-off-by: NLars-Peter Clausen <lars@metafoo.de>
Cc: Oleksandr Kravchenko <o.v.kravchenko@globallogic.com>
Cc: Josh Wu <josh.wu@atmel.com>
Cc: Denis Ciocca <denis.ciocca@gmail.com>
Cc: Manuel Stahl <manuel.stahl@iis.fraunhofer.de>
Cc: Ge Gao <ggao@invensense.com>
Cc: Peter Meerwald <pmeerw@pmeerw.net>
Cc: Jacek Anaszewski <j.anaszewski@samsung.com>
Cc: Fabio Estevam <fabio.estevam@freescale.com>
Cc: Marek Vasut <marex@denx.de>
Signed-off-by: NJonathan Cameron <jic23@kernel.org>

Change the type of the 'data' parameter for iio_push_to_buffers() from 'u8 *' to
'const void *'. Drivers typically use the correct type (e.g. __be16 *) for their
data buffer. When passing the buffer to iio_push_to_buffers() it needs to be
cast to 'u8 *' for the compiler to not complain (and also having to add __force
if we want to keep sparse happy as well). Since the buffer implementation should
not care about the data layout (except the size of one sample) using a void
pointer is the correct thing to do. Also make it const as the buffer
implementations are not supposed to modify it.
Signed-off-by: NLars-Peter Clausen <lars@metafoo.de>
Signed-off-by: NJonathan Cameron <jic23@kernel.org>

These two additional info_mask bitmaps should allow all 'standard'
numeric attributes to be handled using the read_raw and write_raw
callbacks.  Whilst this should reduce code, the more important element
is that this makes these values easily accessible to in kernel users
of IIO devices.
Signed-off-by: NJonathan Cameron <jic23@kernel.org>
Reviewed-by: NLars-Peter Clausen <lars@metafoo.de>

Introduce an enum to specify whether the attribute is separate or
shared.

Factor out the bitmap handling for loop into a separate function.

Tidy up error handling and add a NULL assignment to squish a false
positive warning from GCC.

Change ext_info shared type from boolean to enum and update in all
drivers.
Signed-off-by: NJonathan Cameron <jic23@kernel.org>
Reviewed-by: NLars-Peter Clausen <lars@metafoo.de>

Somehow this got missed when dropping all the code that used it
prior to the split.  Remove it now, there are no users.
Signed-off-by: NJonathan Cameron <jic23@kernel.org>
Reviewed-by: NLars-Peter Clausen <lars@metafoo.de>

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: NLee Jones <lee.jones@linaro.org>
Acked-by: NDenis Ciocca <denis.ciocca@st.com>
Signed-off-by: NJonathan Cameron <jic23@kernel.org>

Integration time is in seconds; it controls the measurement
time and influences the gain of a sensor.

There are two typical ways that scaling is implemented in a device:
1) input amplifier,
2) reference to the ADC is changed.
These both result in the accuracy of the ADC varying (by applying its
sampling over a more relevant range).

Integration time is a way of dealing with noise inherent in the analog
sensor itself.  In the case of a light sensor, a mixture of photon noise
and device specific noise.  Photon noise is dealt with by either improving
the efficiency of the sensor, (more photons actually captured) which is not
easily varied dynamically, or by integrating the measurement over a longer
time period.  Note that this can also be thought of as an averaging of a
number of individual samples and is infact sometimes implemented this way.
Altering integration time implies that the duration of a measurement changes,
a fact the device's user may be interested in.

Hence it makes sense to distinguish between integration time and simple
scale. In some devices both types of control are present and whilst they
will have similar effects on the amplitude of the reading, their effect
on the noise of the measurements will differ considerably.

Used by adjd_s311, tsl4531, tcs3472
The following drivers have similar controls (and could be adapted):
* tsl2563 (integration time is controlled via CALIBSCALE among other things)
* tsl2583 (has integration_time device_attr, but driver doesn't use channels yet)
* tsl2x7x (has integration_time attr)
Signed-off-by: NPeter Meerwald <pmeerw@pmeerw.net>
Cc: Jon Brenner <jon.brenner@ams.com>
Signed-off-by: NJonathan Cameron <jic23@kernel.org>

Signed-off-by: NPeter Meerwald <pmeerw@pmeerw.net>
Signed-off-by: NJonathan Cameron <jic23@kernel.org>

Add a resource managed devm_iio_trigger_alloc()/devm_iio_triger_free()
to automatically clean up triggers allocated by IIO drivers, thus
leading to simplified IIO drivers code.
Signed-off-by: NJacek Anaszewski <j.anaszewski@samsung.com>
Signed-off-by: NKyunmin Park <kyungmin.park@samsung.com>
Signed-off-by: NJonathan Cameron <jic23@kernel.org>

Signed-off-by: NPeter Meerwald <pmeerw@pmeerw.net>
Cc: Grygorii Strashko <grygorii.strashko@ti.com>
Cc: Oleksandr Kravchenko <o.v.kravchenko@globallogic.com>
Signed-off-by: NJonathan Cameron <jic23@kernel.org>

Add a resource managed devm_iio_device_alloc()/devm_iio_device_free()
to automatically clean up any allocations made by IIO drivers,
thus leading to simplified IIO drivers code.

In addition, this will allow IIO drivers to use other devm_*() API
(like devm_request_irq) and don't care about the race between
iio_device_free() and the release of resources by Device core
during driver removing.
Signed-off-by: NGrygorii Strashko <grygorii.strashko@ti.com>
Signed-off-by: NOleksandr Kravchenko <o.v.kravchenko@globallogic.com>
Tested-by: NOleksandr Kravchenko <o.v.kravchenko@globallogic.com>
Reviewed-by: NLars-Peter Clausen <lars@metafoo.de>
Signed-off-by: NJonathan Cameron <jic23@kernel.org>

There are no users of this macro left and we have come to the conclusion that it
is not a good idea to expose the raw chip reset to userspace so the macro is
very unlikely to be used in new drivers.
Signed-off-by: NLars-Peter Clausen <lars@metafoo.de>
Signed-off-by: NJonathan Cameron <jic23@kernel.org>

This patch add support to redirect the DRDY interrupt on INT1 or INT2
on accelerometer and pressure sensors.
Signed-off-by: NDenis Ciocca <denis.ciocca@st.com>
Signed-off-by: NJonathan Cameron <jic23@kernel.org>

When using more than one trigger consumer it can happen that multiple threads
perform a read-modify-update cycle on 'use_count' concurrently. This can cause
updates to be lost and use_count can get stuck at non-zero value, in which case
the IIO core assumes that at least one thread is still running and will wait for
it to finish before running any trigger handlers again. This effectively renders
the trigger disabled and a reboot is necessary before it can be used again. To
fix this make use_count an atomic variable. Also set it to the number of
consumers before starting the first consumer, otherwise it might happen that
use_count drops to 0 even though not all consumers have been run yet.
Signed-off-by: NLars-Peter Clausen <lars@metafoo.de>
Tested-by: NDenis Ciocca <denis.ciocca@st.com>
Signed-off-by: NJonathan Cameron <jic23@kernel.org>

Since the info_mask split, iio_channel_has_info() is not working correctly.
info_mask_separate and info_mask_shared_by_type, it is not possible to compare
them directly with the iio_chan_info_enum enum. Correct that bit using the BIT()
macro.

Cc: <stable@vger.kernel.org> # 3.10.x
Signed-off-by: NAlexandre Belloni <alexandre.belloni@free-electrons.com>
Signed-off-by: NJonathan Cameron <jic23@kernel.org>

iio:common: Removed stuff macros, added num_data_channels on st_sensors 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: NDenis Ciocca <denis.ciocca@st.com>
Signed-off-by: NJonathan Cameron <jic23@kernel.org>

Signed-off-by: NDenis Ciocca <denis.ciocca@st.com>
Signed-off-by: NJonathan Cameron <jic23@kernel.org>

Signed-off-by: NMichael Hennerich <michael.hennerich@analog.com>
Reviewed-by: NLars-Peter Clausen <lars@metafoo.de>
Signed-off-by: NJonathan Cameron <jic23@kernel.org>

Use dev_{set,get}_drvdata for managing private data attached to a trigger
instead of using a custom field in the iio_trigger struct.
Signed-off-by: NLars-Peter Clausen <lars@metafoo.de>
Signed-off-by: NJonathan Cameron <jic23@kernel.org>

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: NLars-Peter Clausen <lars@metafoo.de>
Signed-off-by: NJonathan Cameron <jic23@kernel.org>

Signed-off-by: NPaul Bolle <pebolle@tiscali.nl>
Signed-off-by: NJiri Kosina <jkosina@suse.cz>

This has been replaced by the pair of masks info_mask_separate
and info_mask_shared_by_type.  Other variants may follow.
Signed-off-by: NJonathan Cameron <jic23@kernel.org>
Acked-by: NLars-Peter Clausen <lars@metafoo.de>

The original info_mask is going away in favour of the broken out versions.
Signed-off-by: NJonathan Cameron <jic23@kernel.org>
Acked-by: NLars-Peter Clausen <lars@metafoo.de>

The original info_mask is going away in favour of the broken out versions.
Signed-off-by: NJonathan Cameron <jic23@kernel.org>
Acked-by: NLars-Peter Clausen <lars@metafoo.de>

The original info_mask is going away in favour of the broken out versions.
Signed-off-by: NJonathan Cameron <jic23@kernel.org>
Acked-by: NDenis Ciocca <denis.ciocca@st.com>

This simplifies the code, removes an extensive layer of 'helper' macros
and gives us twice as much room to play with in these masks before we
have any need to be clever.
Signed-off-by: NJonathan Cameron <jic23@kernel.org>
Acked-by: NLars-Peter Clausen <lars@metafoo.de>

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: NGuenter Roeck <linux@roeck-us.net>
Acked-by: NDenis Ciocca <denis.ciocca@st.com>
Signed-off-by: NJonathan Cameron <jic23@kernel.org>

Also include a couple of forward defs of struct iio_trigger and struct
iio_trigger_ops to avoid doing this in each driver.
Signed-off-by: NJonathan Cameron <jic23@kernel.org>
Reported-by: NRandy Dunlap <rdunlap@infradead.org>
Acked-by: NDenis Ciocca <denis.ciocca@st.com>

This patch resolve a bugfix when driver is compiled without trigger.
Signed-off-by: NDenis Ciocca <denis.ciocca@st.com>
Reported-by: NRandy Dunlap  <rdunlap@infradead.org>
Signed-off-by: NJonathan Cameron <jic23@kernel.org>

For iio_channel_get to work with OF based configurations, it needs the
consumer device pointer instead of the consumer device name as argument.
Signed-off-by: NGuenter Roeck <linux@roeck-us.net>
Acked-by: NAnton Vorontsov <anton@enomsg.org>
Acked-by: NChanwoo Choi <cw00.choi@samsung.com>
Signed-off-by: NJonathan Cameron <jic23@kernel.org>

Instead of requiring the map to unregister, simply unregister all map entries
associated with the given iio device. This simplifies map removal and also works
for maps generated through devicetree.
Signed-off-by: NGuenter Roeck <linux@roeck-us.net>
Signed-off-by: NJonathan Cameron <jic23@kernel.org>

Pass device pointer instead of device name as parameter to iio_channel_get_all
and iio_channel_get_all_cb. This will enable us to use OF information to
retrieve consumer channel information.
Signed-off-by: NGuenter Roeck <linux@roeck-us.net>
Signed-off-by: NJonathan Cameron <jic23@kernel.org>

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: NDenis Ciocca <denis.ciocca@st.com>
Signed-off-by: NJonathan Cameron <jic23@kernel.org>

This patch adds support for the InvenSense itg3200.
The itg3200 is a three-axis gyro with 16-bit ADC and
I2C interface.
Signed-off-by: NManuel Stahl <manuel.stahl@iis.fraunhofer.de>
Reviewed-by: NLars-Peter Clausen <lars@metafoo.de>
Signed-off-by: NJonathan Cameron <jic23@kernel.org>

__iio_update_buffer updates the buffer's bytes_per_datum and length fields.
But the only user of this function just passes in these exact fields, so the
call basically looks like this:

	buffer->bytes_per_datum = buffer->bytes_per_datum;
	buffer->length = buffer->length;

Which means it is a noop and can be removed. Also remove the function itself,
since it is now unused.
Signed-off-by: NLars-Peter Clausen <lars@metafoo.de>
Signed-off-by: NJonathan Cameron <jic23@kernel.org>

This patch add a generic library for STMicroelectronics 3-axis sensors.
Signed-off-by: NDenis Ciocca <denis.ciocca@st.com>
Reviewed-by: NLars-Peter Clausen <lars@metafoo.de>
Signed-off-by: NJonathan Cameron <jic23@kernel.org>

This patch adds support for the ADIS16375, ADIS16480, ADIS16485, ADIS16488 6
degree to 10 degree of freedom IMUs.
Signed-off-by: NLars-Peter Clausen <lars@metafoo.de>
Signed-off-by: NJonathan Cameron <jic23@kernel.org>