Extend the inkern API with functions for reading and writing
attribute of iio channels.
Signed-off-by: NArnaud Pouliquen <arnaud.pouliquen@st.com>
Reviewed-by: NJonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: NMark Brown <broonie@kernel.org>

Now that we have a custom printf format specifier, convert users of
full_name to use %pOF instead. This is preparation to remove storing
of the full path string for each node.
Signed-off-by: NRob Herring <robh@kernel.org>
Cc: Jonathan Cameron <jic23@kernel.org>
Cc: Hartmut Knaack <knaack.h@gmx.de>
Cc: Lars-Peter Clausen <lars@metafoo.de>
Cc: Peter Meerwald-Stadler <pmeerw@pmeerw.net>
Cc: Carlo Caione <carlo@caione.org>
Cc: Kevin Hilman <khilman@baylibre.com>
Cc: linux-iio@vger.kernel.org
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-amlogic@lists.infradead.org
Signed-off-by: NJonathan Cameron <Jonathan.Cameron@huawei.com>

When adding maps to the list, they were added using list_add, which adds
them in LIFO order. When parsing using iio_channel_get_all(), these
elements are hence returned in reverse order. As a result, the iio_hwmon
mapping maps the first entry to the last channel and so on.
Signed-off-by: NGaurav Gupta <gauragup@cisco.com>
Signed-off-by: NJonathan Cameron <Jonathan.Cameron@huawei.com>

Extend the inkern api with functions for reading and writing ext_info
of iio channels.
Acked-by: NJonathan Cameron <jic23@kernel.org>
Signed-off-by: NPeter Rosin <peda@axentia.se>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Avoid this smatch error:
drivers/iio/inkern.c:751 iio_read_avail_channel_raw() error: double unlock 'mutex:&chan->indio_dev->info_exist_lock'

Fixes: 00c5f80c ("iio: inkern: add helpers to query available values from channels")
Signed-off-by: NPeter Rosin <peda@axentia.se>
Signed-off-by: NJonathan Cameron <jic23@kernel.org>

When a consumer calls iio_read_channel_processed() the IIO core
tries to apply scaling to the value, but if the channel only
supports reading raw values, we should return that raw value
to the cosumer instead of an error.

This is what userspace is expected to do with sensors only
providing raw values so the kernel should do the same, so as to
avoid adding scaling boilerplate to drivers for hardware that
actually return processed values from raw reads.

A sensor not providing a scale, but providing a _raw attribute
could be valid if for example the scale is the default of 1,
but an offset needs to be applied to convert to the _processed
form.
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>
Signed-off-by: NJonathan Cameron <jic23@kernel.org>

Specifically a helper for reading the available maximum raw value of a
channel and a helper for forwarding read_avail requests for raw values
from one iio driver to an iio channel that is consumed.

These rather specific helpers are in turn built with generic helpers
making it easy to build more helpers for available values as needed.
Signed-off-by: NPeter Rosin <peda@axentia.se>
Signed-off-by: NJonathan Cameron <jic23@kernel.org>

Allow access to underlying channel IIO_CHAN_INFO_OFFSET from a consumer.
Signed-off-by: NMatt Ranostay <matt@ranostay.consulting>
Signed-off-by: NJonathan Cameron <jic23@kernel.org>

Some of kernel driver uses the IIO framework to get the sensor
value via ADC or IIO HW driver. The client driver get iio channel
by iio_channel_get_all() and release it by calling
iio_channel_release_all().

Add resource managed version (devm_*) of these APIs so that if client
calls the devm_iio_channel_get_all() then it need not to release it
explicitly, it can be done by managed device framework when driver
get un-binded.

This reduces the code in error path and also need of .remove callback in
some cases.
Signed-off-by: NLaxman Dewangan <ldewangan@nvidia.com>
Signed-off-by: NJonathan Cameron <jic23@kernel.org>

Some of kernel driver uses the IIO framework to get the sensor
value via ADC or IIO HW driver. The client driver get iio channel
by iio_channel_get() and release it by calling iio_channel_release().

Add resource managed version (devm_*) of these APIs so that if client
calls the devm_iio_channel_get() then it need not to release it explicitly,
it can be done by managed device framework when driver get un-binded.

This reduces the code in error path and also need of .remove callback in
some cases.
Signed-off-by: NLaxman Dewangan <ldewangan@nvidia.com>
Signed-off-by: NJonathan Cameron <jic23@kernel.org>

This fixes the error reported by checkpatch.pl:

ERROR: space required before the open parenthesis '('
Signed-off-by: NSlawomir Stepien <sst@poczta.fm>
Signed-off-by: NJonathan Cameron <jic23@kernel.org>

In twl4030_bci_probe() there are some failure paths where we call
iio_channel_release() with a NULL pointer.  (Apparently, that driver can
opperate without a valid channel pointer).  Let's fix it by adding a
NULL check in iio_channel_release().

Fixes: 2202e1fc ('drivers: power: twl4030_charger: fix link problems when building as module')
Signed-off-by: NDan Carpenter <dan.carpenter@oracle.com>
Cc: <Stable@vger.kernel.org>
Signed-off-by: NJonathan Cameron <jic23@kernel.org>

Use list_for_each_entry_safe instead of list_for_each_safe
and list_entry call.
Signed-off-by: NAnshul Garg <aksgarg1989@gmail.com>
Signed-off-by: NJonathan Cameron <jic23@kernel.org>

If the DT contains an invalid channel specifier then the probe of
iio_hwmon fails with the following message:

iio_hwmon: probe of iio_hwmon failed with error -22

So it's better to print out the relevant channel specifier in
error case to locate the problem.
Signed-off-by: NStefan Wahren <stefan.wahren@i2se.com>
Signed-off-by: NJonathan Cameron <jic23@kernel.org>

When xilinx-xadc is used with hwmon driver to read voltage, offset used
for temperature is always applied whatever the channel.

iio_channel_read must return an error to avoid offset for channel
without IIO_CHAN_INFO_OFFSET property.
Signed-off-by: NFabien Proriol <fabien.proriol@jdsu.com>
Signed-off-by: NJonathan Cameron <jic23@kernel.org>

Introduce API for easy in-kernel setting of DAC values.
Signed-off-by: NDmitry Eremin-Solenikov <dbaryshkov@gmail.com>
Signed-off-by: NJonathan Cameron <jic23@kernel.org>

When #iio-cells is greater than '0', the driver could provide
a custom of_xlate function that reads the *args* and returns
the appropriate index in registered IIO channels array.

Add simple translation function, suitable for the most 1:1
mapped channels in IIO chips, and use it when driver did not
provide custom implementation.
Signed-off-by: NIvan T. Ivanov <iivanov@mm-sol.com>
Reviewed-by: NLars-Peter Clausen <lars@metafoo.de>
Signed-off-by: NJonathan Cameron <jic23@kernel.org>

Fixes: a2c12493 ('iio: of_iio_channel_get_by_name() returns non-null pointers for error legs')

which improperly assumes that of_iio_channel_get_by_name must always
return NULL and thus now hides -EPROBE_DEFER.
Signed-off-by: NJohannes Pointner <johannes.pointner@br-automation.com>
Reviewed-by: NGuenter Roeck <linux@roeck-us.net>
Signed-off-by: NJonathan Cameron <jic23@kernel.org>
Cc: Stable@vger.kernel.org

Currently in the inkern.c code for IIO framework, the function
of_iio_channel_get_by_name() will return a non-NULL pointer when
it cannot find a channel using of_iio_channel_get() and when it
tries to search for 'io-channel-ranges' property and fails. This
is incorrect behaviour as the function which calls this expects
a NULL pointer for failure. This patch rectifies the issue.
Signed-off-by: NAdam Thomson <Adam.Thomson.Opensource@diasemi.com>
Signed-off-by: NJonathan Cameron <jic23@kernel.org>
Cc: Stable@vger.kernel.org

This callback is introduced to overcome some limitations of existing
read_raw callback. The functionality of both existing read_raw and
read_raw_multi is similar, both are used to request values from the
device. The current read_raw callback allows only two return values.
The new read_raw_multi allows returning multiple values. Instead of
passing just address of val and val2, it passes length and pointer
to values. Depending on the type and length of passed buffer, iio
client drivers can return multiple values.
Signed-off-by: NSrinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Signed-off-by: NJonathan Cameron <jic23@kernel.org>

Add iio_read_channel_average_raw to support reading
averaged raw values in consumer drivers.
Signed-off-by: NSebastian Reichel <sre@debian.org>
Signed-off-by: NJonathan Cameron <jic23@kernel.org>

When reading IIO_CHAN_INFO_OFFSET, the return value of iio_channel_read() for
success will be IIO_VAL*, checking for 0 is not correct.

Without this fix the offset applied by iio drivers will be ignored when
converting a raw value to one in appropriate base units (e.g mV) in
a IIO client drivers that use iio_convert_raw_to_processed including
iio-hwmon.

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>

Signed-off-by: NMichael Hennerich <michael.hennerich@analog.com>
Signed-off-by: NJonathan Cameron <jic23@kernel.org>

The code uses

    return foo;
    goto err_type;

when instead the form should have been

    ret = foo;
    goto err_type;

Here this causes a useful iio_device_put to be skipped.
Signed-off-by: NJoe Perches <joe@perches.com>
Signed-off-by: NJonathan Cameron <jic23@kernel.org>

Provide bindings and parse OF data during initialization.
Signed-off-by: NGuenter Roeck <linux@roeck-us.net>
Reviewed-by: NLars-Peter Clausen <lars@metafoo.de>
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>

Used to allow information about a given channel mapping to be passed
through from board files to the consumer drivers.
Signed-off-by: NJonathan Cameron <jic23@kernel.org>

For ADCs or DACs the denominator for fractional types often is a power of two.
In this case we can use a shift operation instead of the rather expensive 64 bit
division. This patch adds a new fractional type which expects the denominator to
be specified as the log2 of the actual denominator. E.g. for ADCs and DACs this
will usually be the number of significant bits.
Signed-off-by: NLars-Peter Clausen <lars@metafoo.de>
Signed-off-by: NJonathan Cameron <jic23@kernel.org>

Fixes the following warnings from coccicheck:
	drivers/iio/inkern.c:81:6-14: WARNING: Comparison to bool
	drivers/iio/dac/ad5686.c:191:5-11: WARNING: Comparison to bool
Signed-off-by: NLars-Peter Clausen <lars@metafoo.de>
Signed-off-by: NJonathan Cameron <jic23@kernel.org>

 When the IIO consumer tries to get specific IIO channel,
 few error cases can be happened.
 (a) Memory allocation failure
 (b) No matched ADC channel error
 (c) Invalid input arguments
 This patch enables cleaning up error handling in case of (a) and (b).

 In error handling code,
 (a): the reference count of the IIO device should be decreased.
 (b): the allocated memory should be freed with restoring the reference count.
 Therefore iio_deivce_put() is called in both cases.
 This can be handled in the last error statement.

 Additionally, integer variable is used for stating each error case explicitly.
 Then, the error returns as ERR_PTR() with this value.
Signed-off-by: NMilo(Woogyom) Kim <milo.kim@ti.com>
Signed-off-by: NJonathan Cameron <jic23@kernel.org>

 The reference count of the IIO device is increased if the IIO map has
 matched consumer name.
 After then, it tries to allocate the iio_channel which is used by the consumer.
 If it fails to allocate memory, the reference count should be decreased.

 This patch enables restoring the reference count of the IIO device.
Signed-off-by: NMilo(Woogyom) Kim <milo.kim@ti.com>
Signed-off-by: NJonathan Cameron <jic23@kernel.org>

Add a function to read a processed value from a channel. The function will first
attempt to read the IIO_CHAN_INFO_PROCESSED attribute. If that fails it will
read the IIO_CHAN_INFO_RAW attribute and convert the result from a raw value to
a processed value.

The patch also introduces a function to convert raw value to a processed value
and exports it, in case a user needs or wants to do the conversion by itself.
Signed-off-by: NLars-Peter Clausen <lars@metafoo.de>
Signed-off-by: NJonathan Cameron <jic23@kernel.org>

 The datasheet name is defined in the IIO driver.
 On the other hand, the adc_channel_label is configured in
 the platform side.
 If the datasheet name is not matched with any adc_channel_label,
 the iio_channel_get() should be returned as error for preventing
 invalid channel data access.

 This can be handled either way.
 (a) checking null data when using it : in the xxx_read_raw()
 or
 (b) error returns when the channel is requested : this patch

 The IIO consumer can't use the channel with invalid channel spec.
 Therefore case (b) is more reasonable.
Signed-off-by: NMilo(Woogyom) Kim <milo.kim@ti.com>
Signed-off-by: NJonathan Cameron <jic23@kernel.org>

 Use kzalloc() rather than kmalloc() for initializing the iio_channel structure.
 This patch enables the iio_dev and iio_chan_spec are set to NULL.
 This may prevent the page fault problem because the pointer of iio_chan_spec
 is initialized as NULL.

 The iio_chan_spec is updated only in case that the IIO map has
 specific channel label.
 When the map has no ADC channel label, then the value of iio_chan_spec
 remains as invalid pointer.
 To prevent this problem, the pointer should be initialized as NULL.
Signed-off-by: NMilo(Woogyom) Kim <milo.kim@ti.com>
Signed-off-by: NJonathan Cameron <jic23@kernel.org>

(a) For better readability, replace 0 with IIO_CHAN_INFO_RAW.
(b) Make same line-format as other apis()
    : iio_read_channel_scale() and iio_read_channel_offset()
Signed-off-by: NMilo(Woogyom) Kim <milo.kim@ti.com>
Signed-off-by: NJonathan Cameron <jic23@kernel.org>

We should be holding the mutex when we goto error_free_chans.
Signed-off-by: NDan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: NJonathan Cameron <jic23@kernel.org>

The device_get is after this point so on error we should not be
removing it.
Signed-off-by: NJonathan Cameron <jic23@kernel.org>

These were originally introduced when the plan was to have parallel
IIO cores in and out of staging with a slow move between them.
Now we have reached the point where the whole core has moved,
they need clearing up!
Signed-off-by: NJonathan Cameron <jic23@kernel.org>