The test in the spear_adc driver which checks whether the IRQ number returned
by platform_get_irq() has multiple problems. It accepts 0 even though this is
an invalid IRQ. It also rejects IRQ numbers that are larger or equal than
NR_IRQS. First of all drivers should never need to reference NR_IRQS and
secondly with CONFIG_SPARSE_IRQ NR_IRQS is not the upper limit, so the check
might reject valid IRQ numbers. This patch modifies the check to only test
against less or equal to 0.
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Reported-by: kbuild test robot <fengguang.wu@intel.com>
Cc: Stefan Roese <sr@denx.de>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

The test in the lpc32xx_adc driver which checks whether the IRQ number returned
by platform_get_irq() has multiple problems. It accepts 0 even though this is an
invalid IRQ. It also rejects IRQ numbers that are larger or equal than NR_IRQS.
First of all drivers should never need to reference NR_IRQS and secondly with
CONFIG_SPARSE_IRQ NR_IRQS is not the upper limit, so the check might reject
valid IRQ numbers. This patch modifies the check to only test against less or
equal to 0.
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Reported-by: kbuild test robot <fengguang.wu@intel.com>
Cc: Roland Stigge <stigge@antcom.de>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

The functionality implemented by iio_sw_buffer_preenable() is now done directly
in the IIO core and previous users of iio_sw_buffer_preenable() have all been
updated to not use it anymore. It is unused now and can be remove.
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

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>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

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>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

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>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

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: Marek Vasut <marex@denx.de>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

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>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

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: Jacek Anaszewski <j.anaszewski@samsung.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

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>

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>

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>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

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>

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: Zubair Lutfullah <zubair.lutfullah@gmail.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

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>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

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>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

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>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

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>

Currently a IIO device driver needs to make sure to update the buffer's bytes
per datum after the scan mask has changed. This is usually done in the preenable
callback by invoking iio_sw_buffer_preenable(). This is something that needs to
be done and is done for virtually all devices which support buffers (we
currently have only one exception). Also this a bit of a layering violation
since we have to call the buffer setup ops from the device setup ops. This
requires the device driver to know about the internal requirements of the buffer
(e.g. whether we need to call the set_bytes_per_datum) callback. And especially
with in-kernel buffer consumers, which allows to attach arbitrary buffers to a
device, this is something that the driver can't know.

Moving this to the core allows us to drop the individual calls to
iio_sw_buffer_preenable() from drivers.
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Cc: Denis Ciocca <denis.ciocca@st.com>
Cc: Marek Vasut <marex@denx.de>
Cc: Zubair Lutfullah <zubair.lutfullah@gmail.com>
Cc: Jacek Anaszewski <j.anaszewski@samsung.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

update_needed is used to decide whether the kfifo buffer needs to be
re-allocated. It is set to true whenever the size of the buffer is changed. It
is never set to false though, causing the buffer to always be re-allocated.
Setting update_needed to false after the new buffer has been allocated fixes the
problem.
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

The kfifo's request_update callback will free the current buffer and allocate a
new one if the size has changed. This will remove any samples that might still
be left in the buffer. If the size has not changed the buffer content is
left untouched though. This is a bit inconsistent and might cause an application
to see data from a previous capture. This patch inserts a call to
kfifo_reset_out() when the size did not change. This makes sure that any pending
samples are removed from the buffer.

Note, due to a different bug the buffer is currently always re-allocated, even
if the size did not change. So this patch will not change the behavior. In the
next patch the bug will be fixed and this patch makes sure that the current
behavior is kept.
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

It is possible for userspace to concurrently access the buffer from multiple
threads or processes. To avoid corruption of the internal state of the buffer we
need to add proper locking. It is possible for multiple processes to try to read
from the buffer concurrently and it is also possible that one process causes a
buffer re-allocation while a different process still access the buffer. Both can
be fixed by protecting the calls to kfifo_to_user() and kfifo_alloc() by the
same mutex. In iio_read_first_n_kfifo() we also use kfifo_recsize() instead of
the buffers bytes_per_datum to avoid a race that can happen if bytes_per_datum
has been changed, but the buffer has not been reallocated yet.

Note that all access to the buffer from within the kernel is already properly
synchronized, so there is no need for extra locking in iio_store_to_kfifo().
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

We need to free the kfifo when we release the buffer, otherwise the fifos memory
will be leaked.
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

None of the SPEAr, LPC32XX or MXS ADC drivers have a compile time dependency on
their respective platform. So make it possible to build the drivers when
CONFIG_COMPILE_TEST is set. This makes it easier to compile test changes.
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Reviewed-by: Marek Vasut <marex@denx.de>
Cc: Stefan Roese <sr@denx.de>
Cc: Roland Stigge <stigge@antcom.de>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

The MXS ADC driver uses the stmp_reset_block() which is only provided when the
STMP_DEVICE Kconfig symbol is selected. Hence the driver should select this
symbol. So far this has not been a problem since the driver depends on ARCH_MXS,
which already selects STMP_DEVICE, but will become necessary once we allow the
driver to be built when COMPILE_TEST is selected.
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Cc: Marek Vasut <marex@denx.de>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

The driver is casting from one __iomem pointer to another. Make sure to include
__iomem in the cast, otherwise sparse will complain with the following warning:

	drivers/staging/iio/adc/spear_adc.c:321:18: warning: cast removes address space of expression
	drivers/staging/iio/adc/spear_adc.c:320:33: warning: incorrect type in assignment (different address spaces)
	drivers/staging/iio/adc/spear_adc.c:320:33:    expected struct adc_regs_spear3xx [noderef] <asn:2>*adc_base_spear3xx
	drivers/staging/iio/adc/spear_adc.c:320:33:    got struct adc_regs_spear3xx *<noident>
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Cc: Stefan Roese <sr@denx.de>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

Remove the scale_mv variable from the read_raw() callback. Fixes the following
warning:
	drivers/staging/iio/adc/spear_adc.c: In function 'spear_read_raw':
	drivers/staging/iio/adc/spear_adc.c:149:6: warning: unused variable 'scale_mv'
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Cc: Stefan Roese <sr@denx.de>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

Since the kernel now disables all buffers when a device is unregistered it might
happen that a in-kernel consumer tries to disable that buffer again. So ignore
requests where the buffer already is in the desired state.
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

Register the event threshold hysteresis attributes by using the new
IIO_EV_INFO_HYSTERESIS event spec type. This allows us to throw away a good
portion of boiler-plate code.
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

Register the event threshold hysteresis attributes by using the new
IIO_EV_INFO_HYSTERESIS event spec type. This allows us to throw away a good
portion of boiler-plate code.
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

Given a channel number the corresponding threshold and hysteresis registers can
easily be calculated. No need to use a look-up table.
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

For some devices it is possible to configure a hysteresis for threshold (or
similar) events. This patch adds a new hysteresis event info type which allows
for easy creation and read/write handling of the sysfs attribute.
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

Switch the tsl2x7x driver to the new IIO event config interface as the old one
is going to be removed.
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Cc: Jon Brenner <jbrenner@taosinc.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

Switch the simple_dummy driver to the new IIO event config interface as the old
one is going to be removed.
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

Switch the ad7150 driver to the new IIO event config interface as the old one
is going to be removed.
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

Switch the ad799x driver to the new IIO event config interface as the old one
is going to be removed.
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

Switch the ad7291 driver to the new IIO event config interface as the old one
is going to be removed.
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

Switch the sca3000 driver to the new IIO event config interface as the old one
is going to be removed.
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

The threshold event can be enabled/disabled separately, but the threshold value
is shared between all three axis.
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

Switch the lis3l02dq driver to the new IIO event config interface as the old one
is going to be removed.
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>