iio: adc: at91-sama5d2: Convert to platform remove callback returning void

The .remove() callback for a platform driver returns an int which makes
many driver authors wrongly assume it's possible to do error handling by
returning an error code. However the value returned is ignored (apart
from emitting a warning) and this typically results in resource leaks.
To improve here there is a quest to make the remove callback return
void. In the first step of this quest all drivers are converted to
.remove_new() which already returns void. Eventually after all drivers
are converted, .remove_new() will be renamed to .remove().

Trivially convert this driver from always returning zero in the remove
callback to the void returning variant.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Link: https://lore.kernel.org/r/20230919174931.1417681-4-u.kleine-koenig@pengutronix.de
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: adc: at91-sama5d2_adc: remove dead code in at91_adc_probe()

From the comment of platform_get_irq(), it only returns non-zero IRQ
number and negative error number, other than zero.

Fix this by removing the if condition.

Signed-off-by: Cheng Ziqiu <chengziqiu@hust.edu.cn>
Reviewed-by: Dongliang Mu <dzm91@hust.edu.cn>
Reviewed-by: Claudiu Beznea <claudiu.beznea@microchip.com>
Link: https://lore.kernel.org/r/20230314070130.60581-1-chengziqiu@hust.edu.cn
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: Rename iio_trigger_poll_chained and add kernel-doc

Rename the function to iio_trigger_poll_nested. Add kernel-doc with
a note on the context where the function is expected to be called.

Signed-off-by: Mehdi Djait <mehdi.djait.k@gmail.com>
Link: https://lore.kernel.org/r/841b533cba28ca25a8e87280c44e45979166e8e2.1677761379.git.mehdi.djait.k@gmail.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: adc: at91-sama5d2_adc: fix an error code in at91_adc_allocate_trigger()

The at91_adc_allocate_trigger() function is supposed to return error
pointers. Returning a NULL will cause an Oops.

Fixes: 5e1a1da0f8c9 ("iio: adc: at91-sama5d2_adc: add hw trigger and buffer support")
Signed-off-by: Dan Carpenter <error27@gmail.com>
Link: https://lore.kernel.org/r/5d728f9d-31d1-410d-a0b3-df6a63a2c8ba@kili.mountain
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: adc: at91-sama5d2_adc: use sysfs_emit() to instead of scnprintf()

Replace the open-code with sysfs_emit() to simplify the code.

Signed-off-by: ye xingchen <ye.xingchen@zte.com.cn>
Link: https://lore.kernel.org/r/202212011142333790361@zte.com.cn
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: Don't silently expect attribute types

The iio_triggered_buffer_setup_ext() and the
devm_iio_kfifo_buffer_setup_ext() were changed by
commit 15097c7a1adc ("iio: buffer: wrap all buffer attributes into iio_dev_attr")
to silently expect that all attributes given in buffer_attrs array are
device-attributes. This expectation was not forced by the API - and some
drivers did register attributes created by IIO_CONST_ATTR().

When using IIO_CONST_ATTRs the added attribute "wrapping" does not copy
the pointer to stored string constant and when the sysfs file is read the
kernel will access to invalid location.

Change the function signatures to expect an array of iio_dev_attrs to
avoid similar errors in the future.

Merge conflict resolved whilst applying due to patch crossing with
two new drivers (kx022a accelerometer and ad4130 ADC).

Signed-off-by: Matti Vaittinen <mazziesaccount@gmail.com>
Tested-by: Claudiu Beznea <claudiu.beznea@microchip.com>
Link: https://lore.kernel.org/r/63f54787a684eb1232f1c5d275a09c786987fe4a.1664782676.git.mazziesaccount@gmail.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: at91-sama5d2_adc: Use IIO_STATIC_CONST_DEVICE_ATTR()

Slightly simplify by dropping open-coded constant data iio_dev_attr
functions and using the IIO_STATIC_CONST_DEVICE_ATTR() instead.

Signed-off-by: Matti Vaittinen <mazziesaccount@gmail.com>
Tested-by: Claudiu Beznea <claudiu.beznea@microchip.com>
Link: https://lore.kernel.org/r/4476a4ce852febb3eb863878e66751c787195b18.1664782676.git.mazziesaccount@gmail.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: adc: at91-sama5d2_adc: get rid of 5 degrees Celsius adjustment

On SAMA7G5 final chip version there is no need for 5 degrees Celsius
adjustment when computing junction temperature, thus, remove it.

Fixes: 5ab38b81895c ("iio: adc: at91-sama5d2_adc: add support for temperature sensor")
Signed-off-by: Claudiu Beznea <claudiu.beznea@microchip.com>
Link: https://lore.kernel.org/r/20221020102705.3639204-1-claudiu.beznea@microchip.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: at91-sama5d2_adc: Fix unsafe buffer attributes

The iio_triggered_buffer_setup_ext() was changed by
commit 15097c7a1adc ("iio: buffer: wrap all buffer attributes into iio_dev_attr")
to silently expect that all attributes given in buffer_attrs array are
device-attributes. This expectation was not forced by the API - and some
drivers did register attributes created by IIO_CONST_ATTR().

The added attribute "wrapping" does not copy the pointer to stored
string constant and when the sysfs file is read the kernel will access
to invalid location.

Change the IIO_CONST_ATTRs from the driver to IIO_DEVICE_ATTR in order
to prevent the invalid memory access.

Signed-off-by: Matti Vaittinen <mazziesaccount@gmail.com>
Fixes: 15097c7a1adc ("iio: buffer: wrap all buffer attributes into iio_dev_attr")
Tested-by: Claudiu Beznea <claudiu.beznea@microchip.com>
Link: https://lore.kernel.org/r/be69775aa302159f088b8b91894e6ec449bca65b.1664782676.git.mazziesaccount@gmail.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: adc: at91-sama5d2_adc: convert to device properties

Make the conversion to firmware agnostic device properties. As part of
the conversion the IIO inkern interface 'of_xlate()' is also converted to
'fwnode_xlate()'. The goal is to completely drop 'of_xlate' and hence OF
dependencies from IIO.

Signed-off-by: Nuno Sá <nuno.sa@analog.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Reviewed-by: Claudiu Beznea <claudiu.beznea@microchip.com>
Link: https://lore.kernel.org/r/20220715122903.332535-10-nuno.sa@analog.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: adc: at91-sama5d2_adc: add runtime pm support

Add runtime PM support by disabling/enabling ADC's peripheral clock.
On simple conversion the ADC's clock is kept enabled just while the
conversion is in progress. This includes also temperature conversion.
For triggered buffers and touch conversions the ADC clock is kept enabled
while the triggered buffers or touch are enabled. Along with it removed
the __maybe_unused on suspend() and resume() ops as the dev_pm_ops
object members are now filled with SYSTEM_SLEEP_PM_OPS().

Signed-off-by: Claudiu Beznea <claudiu.beznea@microchip.com>
Link: https://lore.kernel.org/r/20220803102855.2191070-20-claudiu.beznea@microchip.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: adc: at91-sama5d2_adc: add empty line after functions

Add empty line after function.

Signed-off-by: Claudiu Beznea <claudiu.beznea@microchip.com>
Link: https://lore.kernel.org/r/20220803102855.2191070-19-claudiu.beznea@microchip.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: adc: at91-sama5d2_adc: add support for temperature sensor

The ADC on SAMA7G5 has a dedicated channel (channel 31) for measuring
in-SoC temperature. 2 inputs are multiplexed on channel 31, VTEMP and
VBG as follows:

`
| \ +-----+
VBG --->| | ch31 | |
Vtemp --->| |----->| ADC |
| / | |
| / +-----+
.

where:
- VTEMP is proportional to the absolute temperature voltage
- VBG is a quasi-temperature independent voltage

Both VBG and VTEMP are needed to determine the correct in-SoC
temperature. At a moment of time only one of these could be measured, the
selection being done with bit SRCLCH bit of ACR register. The formula to
calculate the temperature is as follows:

P1 + (Vref * (VTEMP - P6 - P4 * VBG)) / (VBG * VTEMP_DT)

where:
- P1, P4, P6 are calibration data retrieved from OTP memory
- Vref is the reference voltage for ADC
- VTEMP_DT is the voltage sensitivity to temperature and is constant
- VTEMP, VBG are the measured values from channel 31

For better resolution before reading the temperature certain settings
for oversampling ratio, sample frequency, EMR.TRACKX, MR.TRACKTIM are
applied. The initial settings are reapplied at the end of temperature
reading.

Current support is not integrated with trigger buffers channel 31 not
being enabled/disabled in functions at91_adc_buffer_prepare(),
at91_adc_buffer_postdisable() thus the conversion for channel 31 is not
done in case trigger buffers are enabled. In case of trigger buffers are
enabled and temperature requests are received in the driver though
at91_adc_read_temp() the at91_adc_read_temp() will return with an error
code.

Signed-off-by: Claudiu Beznea <claudiu.beznea@microchip.com>
Link: https://lore.kernel.org/r/20220803102855.2191070-18-claudiu.beznea@microchip.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: adc: at91-sama5d2_adc: lock around at91_adc_read_info_raw()

Remove iio_device_{claim, release}_direct_mode() and lock/unlock to
&st->lock from at91_adc_read_info_raw(). Instead add a wrapper around
at91_adc_read_info_raw() and do there the lock/unlock. This will allow
using the at91_adc_read_info_raw() in patch that add support for
temperature sensor.

Signed-off-by: Claudiu Beznea <claudiu.beznea@microchip.com>
Link: https://lore.kernel.org/r/20220803102855.2191070-16-claudiu.beznea@microchip.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: adc: at91-sama5d2_adc: add startup and tracktim as parameter for at91_adc_setup_samp_freq()

Add startup and tracktim as parameter for at91_adc_setup_samp_freq()
function. In case of temperature sensor being enabled these parameters
will be configured on temperature read request to improve the accuracy
of the read temperature.

Signed-off-by: Claudiu Beznea <claudiu.beznea@microchip.com>
Link: https://lore.kernel.org/r/20220803102855.2191070-15-claudiu.beznea@microchip.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: adc: at91-sama5d2_adc: update trackx on emr

Add support for updating trackx bits of EMR register. Having different
values of EMR.TRACKX when measuring temperature give a better accuracy.

Signed-off-by: Claudiu Beznea <claudiu.beznea@microchip.com>
Link: https://lore.kernel.org/r/20220803102855.2191070-14-claudiu.beznea@microchip.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: adc: at91-sama5d2_adc: move oversampling storage in its function

Move the storage of oversampling_ratio in at91_adc_config_emr().
This prepares for the next commits.

Signed-off-by: Claudiu Beznea <claudiu.beznea@microchip.com>
Link: https://lore.kernel.org/r/20220803102855.2191070-13-claudiu.beznea@microchip.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: adc: at91-sama5d2_adc: add 64 and 256 oversampling ratio

Add 64 and 256 oversampling ratio support. It is necessary for temperature
sensor.

Signed-off-by: Claudiu Beznea <claudiu.beznea@microchip.com>
Link: https://lore.kernel.org/r/20220803102855.2191070-12-claudiu.beznea@microchip.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: adc: at91-sama5d2_adc: adjust osr based on specific platform data

ADC captures data on 12 bits (if oversampling is not enabled). When using
oversampling captured data could go up to 14 bits for SAMA5D2 or up to
16 bits for SAMA7G5 (depending on oversampling settings). All the channels
that are subject of oversampling are registered as 14 or 16 real bits.
Depending on the oversampling settings the ADC converted value need to be
shifted up to 14 or 16 to cope with realbits value registered to IIO
subsystem. Commit adds platform specific information to know if we
run on a system with up to 14 or 16 bits ADC converted data.

Signed-off-by: Claudiu Beznea <claudiu.beznea@microchip.com>
Link: https://lore.kernel.org/r/20220803102855.2191070-11-claudiu.beznea@microchip.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: adc: at91-sama5d2_adc: add .read_avail() chan_info ops

Add .read_avail() to chan_info ops which will retrieve the available
oversampling ratio.

Suggested-by: Jonathan Cameron <jic23@kernel.org>
Signed-off-by: Claudiu Beznea <claudiu.beznea@microchip.com>
Link: https://lore.kernel.org/r/20220803102855.2191070-10-claudiu.beznea@microchip.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: adc: at91-sama5d2_adc: drop AT91_OSR_XSAMPLES defines

Drop AT91_OSR_1SAMPLES, AT91_OSR_4SAMPLES, AT91_OSR_16SAMPLES defines
and insted use their values inline.

Suggested-by: Jonathan Cameron <jic23@kernel.org>
Signed-off-by: Claudiu Beznea <claudiu.beznea@microchip.com>
Link: https://lore.kernel.org/r/20220803102855.2191070-9-claudiu.beznea@microchip.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: adc: at91-sama5d2_adc: move the check of oversampling in its function

Oversampling values are checked anyway in at91_adc_emr_config(). Remove
the checking of these from at91_adc_write_raw() and return -EINVAL
instead in at91_adc_emr_config().

Suggested-by: Jonathan Cameron <jic23@kernel.org>
Signed-off-by: Claudiu Beznea <claudiu.beznea@microchip.com>
Link: https://lore.kernel.org/r/20220803102855.2191070-8-claudiu.beznea@microchip.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: adc: at91-sama5d2_adc: handle different EMR.OSR for different hw versions

SAMA7G5 introduces 64 and 256 oversampling rates. Due to this EMR.OSR is 3
bits long. Change the code to reflect this. Commit prepares the code
for the addition of 64 and 256 oversampling rates.

Signed-off-by: Claudiu Beznea <claudiu.beznea@microchip.com>
Link: https://lore.kernel.org/r/20220803102855.2191070-7-claudiu.beznea@microchip.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: adc: at91-sama5d2_adc: exit from write_raw() when buffers are enabled

When buffers are enabled conversion may start asynchronously thus
allowing changes on actual hardware could lead to bad behavior. Thus
do not allow changing oversampling ratio and sample frequency when
if iio_device_claim_direct_mode() returns with error.

Signed-off-by: Claudiu Beznea <claudiu.beznea@microchip.com>
Link: https://lore.kernel.org/r/20220803102855.2191070-6-claudiu.beznea@microchip.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: adc: at91-sama5d2_adc: disable/prepare buffer on suspend/resume

In case triggered buffers are enabled while system is suspended they will
not work anymore after resume. For this call at91_adc_buffer_postdisable()
on suspend and at91_adc_buffer_prepare() on resume. On tests it has been
seen that at91_adc_buffer_postdisable() call is not necessary but it has
been kept because it also does the book keeping for DMA. On resume path
there is no need to call at91_adc_configure_touch() as it is embedded in
at91_adc_buffer_prepare().

Fixes: 073c662017f2f ("iio: adc: at91-sama5d2_adc: add support for DMA")
Signed-off-by: Claudiu Beznea <claudiu.beznea@microchip.com>
Link: https://lore.kernel.org/r/20220803102855.2191070-5-claudiu.beznea@microchip.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: adc: at91-sama5d2_adc: lock around oversampling and sample freq

.read_raw()/.write_raw() could be called asynchronously from user space
or other in kernel drivers. Without locking on st->lock these could be
called asynchronously while there is a conversion in progress. Read will
be harmless but changing registers while conversion is in progress may
lead to inconsistent results. Thus, to avoid this lock st->lock.

Fixes: 27e177190891 ("iio:adc:at91_adc8xx: introduce new atmel adc driver")
Fixes: 6794e23fa3fe ("iio: adc: at91-sama5d2_adc: add support for oversampling resolution")
Signed-off-by: Claudiu Beznea <claudiu.beznea@microchip.com>
Link: https://lore.kernel.org/r/20220803102855.2191070-4-claudiu.beznea@microchip.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: adc: at91-sama5d2_adc: check return status for pressure and touch

Check return status of at91_adc_read_position() and
at91_adc_read_pressure() in at91_adc_read_info_raw().

Fixes: 6794e23fa3fe ("iio: adc: at91-sama5d2_adc: add support for oversampling resolution")
Signed-off-by: Claudiu Beznea <claudiu.beznea@microchip.com>
Link: https://lore.kernel.org/r/20220803102855.2191070-3-claudiu.beznea@microchip.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: adc: at91-sama5d2_adc: fix AT91_SAMA5D2_MR_TRACKTIM_MAX

All ADC HW versions handled by this driver (SAMA5D2, SAM9X60, SAMA7G5)
have MR.TRACKTIM on 4 bits. Fix AT91_SAMA5D2_MR_TRACKTIM_MAX to reflect
this.

Fixes: 27e177190891 ("iio:adc:at91_adc8xx: introduce new atmel adc driver")
Signed-off-by: Claudiu Beznea <claudiu.beznea@microchip.com>
Link: https://lore.kernel.org/r/20220803102855.2191070-2-claudiu.beznea@microchip.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: adc: at91-sam5d2: Switch to DEFINE_SIMPLE_DEV_PM_OPS() and pm_sleep_ptr()

Using these newer macros allows the compiler to remove the unused
structure and functions when !CONFIG_PM_SLEEP + removes the need to
mark pm functions __maybe_unused.

Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Cc: Eugen Hristev <eugen.hristev@microchip.com>
Cc: Nicolas Ferre <nicolas.ferre@microchip.com>
Cc: Alexandre Belloni <alexandre.belloni@bootlin.com>
Cc: Ludovic Desroches <ludovic.desroches@microchip.com>
Reviewed-by: Paul Cercueil <paul@crapouillou.net>
Link: https://lore.kernel.org/r/20220621202719.13644-4-jic23@kernel.org

iio: at91-sama5d2: Limit requested watermark value to hwfifo size

Instead of returning an error if the watermark value is too high, which
the core will silently ignore anyway, limit the value to the hardware
FIFO size; a lower-than-requested value is still better than using the
default, which is usually 1.

Cc: Eugen Hristev <eugen.hristev@microchip.com>
Cc: Nicolas Ferre <nicolas.ferre@microchip.com>
Cc: Alexandre Belloni <alexandre.belloni@bootlin.com>
Cc: Ludovic Desroches <ludovic.desroches@microchip.com>
Signed-off-by: Paul Cercueil <paul@crapouillou.net>
Link: https://lore.kernel.org/r/20220117102512.31725-2-paul@crapouillou.net
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: core: Hide read accesses to iio_dev->currentmode

In order to later move this variable within the opaque structure, let's
create a helper for accessing it in read-only mode. This helper will be
exposed to device drivers and kept accessible for the few that could need
it. The write access to this variable however should be fully reserved to
the core so in a second step we will hide this variable into the opaque
structure.

Cc: Eugen Hristev <eugen.hristev@microchip.com>
Cc: Nicolas Ferre <nicolas.ferre@microchip.com>
Cc: Alexandre Belloni <alexandre.belloni@bootlin.com>
Cc: Ludovic Desroches <ludovic.desroches@microchip.com>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Link: https://lore.kernel.org/r/20220207143840.707510-11-miquel.raynal@bootlin.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: at91-sama5d2: Use dev_to_iio_dev() in sysfs callbacks

Using `dev_get_drvdata()` in IIO sysfs callbacks to get a pointer to the
IIO device is a relic from the very early days of IIO. The IIO core as well
as most other drivers have switched over to using `dev_to_iio_dev()`
instead.

This driver is one of the last few drivers remaining that uses the outdated
idiom, update it. This will allow to eventually update the IIO core to no
longer set the drvdata for the IIO device and free it up for driver usage.

Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Link: https://lore.kernel.org/r/20211019082929.30503-2-lars@metafoo.de
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: at91-sama5d2: Fix incorrect cast to platform_device

The at91-sama5d2 driver calls `to_platform_device()` on a struct device
that is part of a IIO device. This is incorrect since
`to_platform_device()` must only be called on a struct device that is part
of a platform device.

The code still works by accident because non of the struct platform_device
specific fields are accessed.

Refactor the code a bit so that it behaves identically, but does not use
the incorrect cast. This avoids accidentally adding undefined behavior in
the future by assuming the `struct platform_device` is actually valid.

Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Tested-by: Eugen Hristev <eugen.hristev@microchip.com>
Link: https://lore.kernel.org/r/20211019082929.30503-1-lars@metafoo.de
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: at91-sama5d2: Fix incorrect sign extension

Use scan_type when processing raw data which also fixes that the sign
extension was from the wrong bit.

Use channel definition as root of trust and replace constant
when reading elements directly using the raw sysfs attributes.

Fixes: 6794e23fa3fe ("iio: adc: at91-sama5d2_adc: add support for oversampling resolution")
Signed-off-by: Gwendal Grignou <gwendal@chromium.org>
Reviewed-by: Eugen Hristev <eugen.hristev@microchip.com>
Cc: <Stable@vger.kernel.org>
Link: https://lore.kernel.org/r/20211104082413.3681212-9-gwendal@chromium.org
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: triggered-buffer: extend support to configure output buffers

Now that output (kfifo) buffers are supported, we need to extend the
{devm_}iio_triggered_buffer_setup_ext() parameter list to take a direction
parameter.

This allows us to attach an output triggered buffer to a DAC device.
Unfortunately it's a bit difficult to add another macro to avoid changing 5
drivers where {devm_}iio_triggered_buffer_setup_ext() is used.
Well, it's doable, but may not be worth the trouble vs just updating all
these 5 drivers.

Signed-off-by: Alexandru Ardelean <alexandru.ardelean@analog.com>
Signed-off-by: Mihail Chindris <mihail.chindris@analog.com>
Link: https://lore.kernel.org/r/20211007080035.2531-4-mihail.chindris@analog.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: adc: at91-sama5d2_adc: update copyright and authors information

Update copyright and authors information (corrected e-mail address), and
add myself as one of the authors.

Signed-off-by: Eugen Hristev <eugen.hristev@microchip.com>
Link: https://lore.kernel.org/r/20210901123013.329792-9-eugen.hristev@microchip.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: adc: at91-sama5d2_adc: add support for sama7g5 device

Add support to sama7g5 ADC which is similar with sama5d2/sam9x60 device.
Differences are highlighted by compatible.
Main differences include 16 channels instead of 12 and missing
resistive touchscreen.

Signed-off-by: Eugen Hristev <eugen.hristev@microchip.com>
Link: https://lore.kernel.org/r/20210901123013.329792-8-eugen.hristev@microchip.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: adc: at91-sama5d2_adc: add helper for COR register

Add helper for the COR register. This helper allows to modify the COR
register, removes duplicate code and improves readability.
The COR offset is now part of the register layout. This will allow
different platform with a different offset to use the same helper.

Signed-off-by: Eugen Hristev <eugen.hristev@microchip.com>
Link: https://lore.kernel.org/r/20210901123013.329792-7-eugen.hristev@microchip.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: adc: at91-sama5d2_adc: add support for separate end of conversion registers

Some platforms have separated the end-of-conversion information from the
usual ISR/IMR/IER/IDR registers, into EOC_ISR/EOC_IMR/EOC_IER/EOC_IDR.
To cope with both variants, helpers are being added, that will make
code more clear and more easy to read.

Signed-off-by: Eugen Hristev <eugen.hristev@microchip.com>
Link: https://lore.kernel.org/r/20210901123013.329792-6-eugen.hristev@microchip.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: adc: at91-sama5d2_adc: convert to platform specific data structures

Convert the driver to platform specific structures. This means:
- create a register layout struct that will hold offsets for registers
- create a platform struct that will hold platform information (number of
channels, indexes for different channels and pointer to layout struct)
- convert specific macros that are platform dependent into platform variables

This step is in fact a no-op, but allows the driver to be more flexible
and for future enhancement including adding new platforms that are partly
compatible with the current driver and differ slightly in register layout
or capabilities for example.

Signed-off-by: Eugen Hristev <eugen.hristev@microchip.com>
Link: https://lore.kernel.org/r/20210901123013.329792-5-eugen.hristev@microchip.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: adc: at91-sama5d2_adc: remove unused definition

Remove unused register definition

Signed-off-by: Eugen Hristev <eugen.hristev@microchip.com>
Link: https://lore.kernel.org/r/20210901123013.329792-4-eugen.hristev@microchip.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: adc: at91-sama5d2_adc: initialize hardware after clock is started

The hw_init hardware init call must happen after the clock is prepared and
enabled. Otherwise, writing to the registers might lead to a block or
external abort.

Signed-off-by: Eugen Hristev <eugen.hristev@microchip.com>
Link: https://lore.kernel.org/r/20210901123013.329792-3-eugen.hristev@microchip.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: adc: at91-sama5d2: Fix buffer alignment in iio_push_to_buffers_with_timestamp()

To make code more readable, use a structure to express the channel
layout and ensure the timestamp is 8 byte aligned.

Found during an audit of all calls of this function.

Fixes: 5e1a1da0f8c9 ("iio: adc: at91-sama5d2_adc: add hw trigger and buffer support")
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Cc: Eugen Hristev <eugen.hristev@microchip.com>
Reviewed-by: Nuno Sá <nuno.sa@analog.com>
Link: https://lore.kernel.org/r/20210613152301.571002-2-jic23@kernel.org

iio: core: move @id from struct iio_dev to struct iio_dev_opaque

Continuing from Alexandru Ardelean's introduction of the split between
driver modifiable fields and those that should only be set by the core.

This could have been done in two steps to make the actual move after
introducing iio_device_id() but there seemed limited point to that
given how mechanical the majority of the patch is.

Includes fixup from Alex for missing mxs-lradc-adc conversion.

Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Reviewed-by: Alexandru Ardelean <ardeleanalex@gmail.com>
Link: https://lore.kernel.org/r/20210426174911.397061-2-jic23@kernel.org

iio:trigger: rename try_reenable() to reenable() plus return void

As we no longer support a try again if we cannot reenable the trigger
rename the function to reflect this. Also we don't do anything with
the value returned so stop it returning anything. For the few drivers
that didn't already print an error message in this patch, add such
a print.

Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Reviewed-by: Lars-Peter Clausen <lars@metafoo.de>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Acked-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Cc: Linus Walleij <linus.walleij@linaro.org>
Cc: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Cc: Christian Oder <me@myself5.de>
Cc: Eugen Hristev <eugen.hristev@microchip.com>
Cc: Nishant Malpani <nish.malpani25@gmail.com>
Cc: Daniel Baluta <daniel.baluta@oss.nxp.com>
Link: https://lore.kernel.org/r/20200920132548.196452-3-jic23@kernel.org

iio: adc: at91-sama5d2_adc: use devm_iio_triggered_buffer_setup_ext()

This change switches to the new devm_iio_triggered_buffer_setup_ext()
function and removes the iio_buffer_set_attrs() call, for assigning the
HW FIFO attributes to the buffer.

Signed-off-by: Alexandru Ardelean <alexandru.ardelean@analog.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Link: https://lore.kernel.org/r/20200929125949.69934-7-alexandru.ardelean@analog.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: adc: at91-sama5d2_adc: merge buffer & trigger init into a function

This change is mostly cosmetic, but it's also a pre-cursor to the
the change for 'iio_buffer_set_attrs()', where the helper gets updated to
better support multiple IIO buffers for 1 IIO device.

The only functional change is that the error message for the trigger alloc
failure is bound to the parent device vs the IIO device object.

Also, the new at91_adc_buffer_and_trigger_init() function was moved after
the definition of the 'at91_adc_fifo_attributes'.

Signed-off-by: Alexandru Ardelean <alexandru.ardelean@analog.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Link: https://lore.kernel.org/r/20200929125949.69934-3-alexandru.ardelean@analog.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: adc: at91-sama5d2_adc: remove unneeded semicolon

A semicolon is not needed after a switch statement.

Signed-off-by: Tom Rix <trix@redhat.com>
Link: https://lore.kernel.org/r/20201027200853.1596699-1-trix@redhat.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: adc: at91-sama5d2_adc: fix DMA conversion crash

After the move of the postenable code to preenable, the DMA start was
done before the DMA init, which is not correct.
The DMA is initialized in set_watermark. Because of this, we need to call
the DMA start functions in set_watermark, after the DMA init, instead of
preenable hook, when the DMA is not properly setup yet.

Fixes: f3c034f61775 ("iio: at91-sama5d2_adc: adjust iio_triggered_buffer_{predisable,postenable} positions")
Signed-off-by: Eugen Hristev <eugen.hristev@microchip.com>
Link: https://lore.kernel.org/r/20200923121748.49384-1-eugen.hristev@microchip.com
Cc: <Stable@vger.kernel.org>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: adc: at91-sama5d2_adc: Use devm_platform_get_and_ioremap_resource()

Make use of devm_platform_get_and_ioremap_resource() provided by
driver core platform instead of duplicated analogue.

Signed-off-by: Wang ShaoBo <bobo.shaobowang@huawei.com>
Link: https://lore.kernel.org/r/20200918082837.32610-1-bobo.shaobowang@huawei.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: adc: at91-sama5d2_adc: Struct kerneldoc titles need to start with 'struct '

Fixes the following W=1 kernel build warning(s):

drivers/iio/adc/at91-sama5d2_adc.c:360: warning: cannot understand function prototype: 'struct at91_adc_dma '
drivers/iio/adc/at91-sama5d2_adc.c:379: warning: cannot understand function prototype: 'struct at91_adc_touch '

Cc: Ludovic Desroches <ludovic.desroches@microchip.com>
Cc: Eugen Hristev <eugen.hristev@microchip.com>
Cc: Nicolas Ferre <nicolas.ferre@microchip.com>
Cc: Alexandre Belloni <alexandre.belloni@bootlin.com>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: at91-sama5d2_adc: remove usage of iio_priv_to_dev() helper

We may want to get rid of the iio_priv_to_dev() helper. The reason is that
we will hide some of the members of the iio_dev structure (to prevent
drivers from accessing them directly), and that will also mean hiding the
implementation of the iio_priv_to_dev() helper inside the IIO core.

Hiding the implementation of iio_priv_to_dev() implies that some fast-paths
may not be fast anymore, so a general idea is to try to get rid of the
iio_priv_to_dev() altogether.
The iio_priv() helper won't be affected by the rework, as the iio_dev
struct will keep a reference to the private information.

For this driver, not using iio_priv_to_dev(), means reworking some paths to
pass the iio device and using iio_priv() to access the private information,
and also keeping a reference to the iio device for some quirky paths.

One [quirky] path is the at91_adc_workq_handler() which requires the IIO
device & the state struct to push to buffers.
Since this requires the back-ref to the IIO device, the
at91_adc_touch_pos() also uses it. This simplifies the patch a bit. The
information required in this function is mostly for debugging purposes.
Replacing it with a reference to the IIO device would have been a slightly
bigger change, which may not be worth it (for just the debugging purpose
and given that we need the back-ref to the IIO device anyway).

Signed-off-by: Alexandru Ardelean <alexandru.ardelean@analog.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: Move attach/detach of the poll func to the core

All devices using a triggered buffer need to attach and detach the trigger
to the device in order to properly work. Instead of doing this in each and
every driver by hand move this into the core.

At this point in time, all drivers should have been resolved to
attach/detach the poll-function in the same order.

This patch removes all explicit calls of iio_triggered_buffer_postenable()
& iio_triggered_buffer_predisable() in all drivers, since the core handles
now the pollfunc attach/detach.

The more peculiar change is for the 'at91-sama5d2_adc' driver, since it's
not immediately obvious that removing the hooks doesn't break anything.
Eugen was able to test on at91-sama5d2-adc driver, sama5d2-xplained board.
All seems to be fine.

Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Alexandru Ardelean <alexandru.ardelean@analog.com>
Tested-by: Eugen Hristev <eugen.hristev@microchip.com> #for at91-sama5d2-adc
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: remove explicit IIO device parent assignment

This patch applies the semantic patch:
@@
expression I, P, SP;
@@
I = devm_iio_device_alloc(P, SP);
...
- I->dev.parent = P;

It updates 302 files and does 307 deletions.
This semantic patch also removes some comments like
'/* Establish that the iio_dev is a child of the i2c device */'

But this is is only done in case where the block is left empty.

The patch does not seem to cover all cases. It looks like in some cases a
different variable is used in some cases to assign the parent, but it
points to the same reference.
In other cases, the block covered by ... may be just too big to be covered
by the semantic patch.

However, this looks pretty good as well, as it does cover a big bulk of the
drivers that should remove the parent assignment.

Signed-off-by: Alexandru Ardelean <alexandru.ardelean@analog.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: at91-sama5d2_adc: adjust iio_triggered_buffer_{predisable,postenable} positions

The iio_triggered_buffer_{predisable,postenable} functions attach/detach
poll functions.

In most cases the iio_triggered_buffer_postenable() should be called first
to attach the poll function, and then the driver can init the data to be
triggered.
In this case it's the other way around: the DMA code should be initialized
before the attaching the poll function and the reverse should be done when
un-initializing.

To make things easier when removing the iio_triggered_buffer_postenable() &
iio_triggered_buffer_predisable() functions from the IIO core API, the DMA
code has been moved into preenable() for init, and postdisable() for
uninit.

Signed-off-by: Alexandru Ardelean <alexandru.ardelean@analog.com>
Reviewed-by: Ludovic Desroches <ludovic.desroches@microchip.com>
Reviewed-by: Eugen Hristev <eugen.hristev@microchip.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: at91-sama5d2_adc: split at91_adc_current_chan_is_touch() helper

This change moves the logic to check if the current channel is the
touchscreen channel to a separate helper.
This reduces some code duplication, but the main intent is to re-use this
in the next patches.

Signed-off-by: Alexandru Ardelean <alexandru.ardelean@analog.com>
Reviewed-by: Eugen Hristev <eugen.hristev@microchip.com>
Reviewed-by: Ludovic Desroches <ludovic.desroches@microchip.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: adc: at91-sama5d2_adc: update for other trigger usage

This change will allow the at91-sama5d2_adc driver to use other triggers
than it's own.
In particular, tested with the sysfs trigger.
To be able to achieve this functionality, some changes were required:
1) Do not enable/disable channels when enabling/disabling the trigger.
This is because the trigger is enabled/disabled only for our trigger
(obviously). We need channels enabled/disabled regardless of what trigger is
being used.
2) Cope with DMA : DMA cannot be used when using another type of trigger.
Other triggers work through pollfunc, so we get polled anyway on every trigger.
Thus we have to obtain data at every trigger.
3) When to start conversion? The usual pollfunc (store time from subsystem)
would be in hard irq and this would be a good way, but current iio subsystem
recommends to have it in the threaded irq. Thus adding software start
code in this handler.
4) Buffer config: we need to setup buffer regardless of our own device's
trigger. We may get one attached later.
5) IRQ handling: we use our own device IRQ only if it's our own trigger
and we do not use DMA . If we use DMA, we use the DMA controller's IRQ.

Signed-off-by: Eugen Hristev <eugen.hristev@microchip.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: adc: at91-sama5d2_adc: handle unfinished conversions

It can happen that on IRQ trigger, not all conversions are done if
we are enabling multiple channels.
The IRQ is triggered on first EOC (end of channel), but it can happen
that not all channels are done. This leads into erroneous reports to
userspace (zero values or previous values).
To solve this, in trigger handler, check if the mask of done channels
is the same as the mask of active scan channels.
If it's the same, proceed and push to buffers. Otherwise, use usleep
to sleep until the conversion is done or we timeout.
Normally, it should happen that in a short time fashion, all channels are
ready, since the first IRQ triggered.
If a hardware fault happens (for example the clock suddently dissappears),
the handler will not be completed, in which case we do not report anything to
userspace anymore.
Also, change from using the EOC interrupts to DRDY interrupt.
This helps with the fact that not 'n' interrupt statuses are enabled,
each being able to trigger an interrupt, and instead only data ready
interrupt can wake up the CPU. Like this, when data is ready, check in
handler which and how many channels are done. While the DRDY is raised,
other IRQs cannot occur. Once the channel data is being read, we ack the
IRQ and finish the conversion.

Signed-off-by: Eugen Hristev <eugen.hristev@microchip.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: adc: at91-sama5d2_adc: fix differential channels in triggered mode

The differential channels require writing the channel offset register (COR).
Otherwise they do not work in differential mode.
The configuration of COR is missing in triggered mode.

Fixes: 5e1a1da0f8c9 ("iio: adc: at91-sama5d2_adc: add hw trigger and buffer support")
Signed-off-by: Eugen Hristev <eugen.hristev@microchip.com>
Cc: <Stable@vger.kernel.org>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: adc: at91-sama5d2_adc: Use dma_request_chan() instead dma_request_slave_channel()

dma_request_slave_channel() is a wrapper on top of dma_request_chan()
eating up the error code.

The dma_request_chan() is the standard API to request slave channel,
clients should be moved away from the legacy API to allow us to retire
them.

Signed-off-by: Peter Ujfalusi <peter.ujfalusi@ti.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: adc: at91-sama5d2: Replace 0 with NULL when clearing some pointers.

Cleans up the sparse warning:

CHECK drivers/iio/adc/at91-sama5d2_adc.c
drivers/iio/adc/at91-sama5d2_adc.c:1486:31: warning: Using plain integer as NULL pointer
drivers/iio/adc/at91-sama5d2_adc.c:1509:31: warning: Using plain integer as NULL pointer

Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Reviewed-by: Eugen Hristev <eugen.hristev@microchip.com>

treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 282

Based on 1 normalized pattern(s):

this software is licensed under the terms of the gnu general public
license version 2 as published by the free software foundation and
may be copied distributed and modified under those terms this
program is distributed in the hope that it will be useful but
without any warranty without even the implied warranty of
merchantability or fitness for a particular purpose see the gnu
general public license for more details

extracted by the scancode license scanner the SPDX license identifier

GPL-2.0-only

has been chosen to replace the boilerplate/reference in 285 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Alexios Zavras <alexios.zavras@intel.com>
Reviewed-by: Allison Randal <allison@lohutok.net>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190529141900.642774971@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

iio: adc: at91: Use dev_get_drvdata()

Using dev_get_drvdata directly.

Cc: Ludovic Desroches <ludovic.desroches@microchip.com>
Cc: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Cc: linux-iio@vger.kernel.org
Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: adc: at91-sama5d2_adc: fix up casting in at91_adc_read_info_raw()

This code is problematic because we're supposed to be writing an int but
we instead write to only the high 16 bits. This doesn't work on big
endian systems, and there is a potential that the bottom 16 bits are
used without being initialized.

Fixes: 23ec2774f1cc ("iio: adc: at91-sama5d2_adc: add support for position and pressure channels")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Tested-by: Eugen Hristev <eugen.hristev@microchip.com>
Acked-by: Ludovic Desroches <ludovic.desroches@microchip.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: adc: at91-sama5d2_adc: add support for oversampling resolution

This implements oversampling support for the SAMA5d2 ADC device.
Enabling oversampling : OSR can improve resolution from 12 bits to
13 or 14 bits.
Changing the channel specification to have 14 bits, and we shift the value
1 bit to the left if we have oversampling for just one extra bit, and two
bits to the left if we have no oversampling (old support).
From this commit on, the converted values for all the voltage channels
change to 14 bits real data, with most insignificant two bits always zero
if oversampling is not enabled.
sysfs object oversampling_ratio has been enabled and
oversampling_ratio_available will list possible values (1 or 4 or 16) having
1 as default (no oversampling, 1 sample for each conversion).
Special care was required for the triggered buffer scenario (+ DMA), to
adjust the values accordingly.
Touchscreen measurements supported by this driver are not affected by
oversampling, they are still on 12 bits (scale handing is already included
in the driver).

Signed-off-by: Eugen Hristev <eugen.hristev@microchip.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: adc: at91-sama5d2_adc: add support for position and pressure channels

This implements the support for position and pressure for the included
touchscreen support in the SAMA5D2 SOC ADC block.
Two position channels are added and one for pressure.
They can be read in raw format, or through a buffer.
A normal use case is for a consumer driver to register a callback buffer
for these channels.
When the touchscreen channels are in the active scan mask,
the driver will start the touchscreen sampling and push the data to the
buffer.

Some parts of this patch are based on initial original work by
Mohamed Jamsheeth Hajanajubudeen and Bandaru Venkateswara Swamy

Signed-off-by: Eugen Hristev <eugen.hristev@microchip.com>
Acked-by: Ludovic Desroches <ludovic.desroches@microchip.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: adc: at91-sama5d2_adc: fix channel configuration for differential channels

When iterating through the channels, the index in the array is not the
scan index. Added an xlate function to translate to the proper index.
The result of the bug is that the channel array is indexed with a wrong index,
thus instead of the proper channel, we access invalid memory, which may
lead to invalid results and/or corruption.
This will be used also for devicetree channel xlate.

Fixes: 5e1a1da0f ("iio: adc: at91-sama5d2_adc: add hw trigger and buffer support")
Fixes: 073c66201 ("iio: adc: at91-sama5d2_adc: add support for DMA")
Signed-off-by: Eugen Hristev <eugen.hristev@microchip.com>
Cc: <Stable@vger.kernel.org>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: adc: at91-sama5d2_adc: ack DRDY irq in direct mode

Need to acknowledge DRDY irq in direct mode/ software
triggered mode. Otherwise, on the next conversion, overrun
flag will be raised, which is not a correct state.
This doesn't affect the functionality, but will generate
possible incorrect overrun reports.

Signed-off-by: Eugen Hristev <eugen.hristev@microchip.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: adc: at91-sama5d2_adc: add support for DMA

Added support for DMA transfers. The implementation uses the user watermark
to decide whether DMA will be used or not. For watermark 1, DMA will not be
used. If watermark is bigger, DMA will be used.
Sysfs attributes are created to indicate whether the DMA is used,
with hwfifo_enabled, and the current DMA watermark is readable
in hwfifo_watermark. Minimum and maximum values are in hwfifo_watermark_min
and hwfifo_watermark_max.

Signed-off-by: Eugen Hristev <eugen.hristev@microchip.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: adc: at91-sama5d2_adc: fix probe error on missing trigger property

This fix allows platforms to probe correctly even if the
trigger edge property is missing. The hardware trigger
will no longer be registered in the sybsystem
Preserves backwards compatibility with the support that
was in the driver before the hardware trigger.

https://storage.kernelci.org/mainline/master/v4.14-rc2-255-g74d83ec2b734/arm/sama5_defconfig/lab-free-electrons/boot-at91-sama5d2_xplained.txt

Signed-off-by: Eugen Hristev <eugen.hristev@microchip.com>
Fixes: 5e1a1da0f ("iio: adc: at91-sama5d2_adc: add hw trigger and buffer support")
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio:adc: drop assign iio_info.driver_module and iio_trigger_ops.owner

The equivalent of both of these are now done via macro magic when
the relevant register calls are made. The actual structure
elements will shortly go away.

Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Reviewed-by: Lars-Peter Clausen <lars@metafoo.de>

iio:adc:at91-sama5d2: make array startup_lookup static to reduce code size

Making the const array startup_lookup static rather having it on the
stack saves 69 bytes. Add in missing int specifier to clean up a
checkpatch warning.

Before:
text data bss dec hex filename
10297 2800 128 13225 33a9 drivers/iio/adc/at91-sama5d2_adc.o

After:
text data bss dec hex filename
10140 2888 128 13156 3364 drivers/iio/adc/at91-sama5d2_adc.o

Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: adc: at91-sama5d2_adc: add support for suspend/resume functionality

Added support for suspend/resume functionality for the ADC IP
in sama5d2 SoC.
In order to enter Suspend to ram mode (backup + self refresh mode for
memory), in which the ADC IP is no longer powered, we need to reset the
pins to default state, for the scenario when they are also used for I2C
bus to communicate with the PMIC.
On resume, we need to reconfigure the ADC IP registers and reconfigure the
trigger registers in the case when the suspend procedure is done while
sysfs has the buffer and trigger enabled.
In the case the suspend happens exactly during a software triggered
conversion, the request will time out, because we reset and power down
the ADC.

Signed-off-by: Eugen Hristev <eugen.hristev@microchip.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

iio: adc: at91-sama5d2_adc: add hw trigger and buffer support

Added support for the external hardware trigger on pin ADTRG,
integrated the three possible edges into the driver
and created buffer management for data retrieval

Signed-off-by: Eugen Hristev <eugen.hristev@microchip.com>
Acked-by: Ludovic Desroches <ludovic.desroches@microchip.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

iio:adc:at91-sama5d2: Repair crash on module removal

The driver never calls platform_set_drvdata() , so platform_get_drvdata()
in .remove returns NULL and thus $indio_dev variable in .remove is NULL.
Then it's only a matter of dereferencing the indio_dev variable to make
the kernel blow as seen below. This patch adds the platform_set_drvdata()
call to fix the problem.

root@armhf:~# rmmod at91-sama5d2_adc

Unable to handle kernel NULL pointer dereference at virtual address 000001d4
pgd = dd57c000
[000001d4] *pgd=00000000
Internal error: Oops: 5 [#1] ARM
Modules linked in: at91_sama5d2_adc(-)
CPU: 0 PID: 1334 Comm: rmmod Not tainted 4.6.0-rc3-next-20160418+ #3
Hardware name: Atmel SAMA5
task: dd4fcc40 ti: de910000 task.ti: de910000
PC is at mutex_lock+0x4/0x24
LR is at iio_device_unregister+0x14/0x6c
pc : [<c05f4624>] lr : [<c0471f74>] psr: a00d0013
sp : de911f00 ip : 00000000 fp : be898bd8
r10: 00000000 r9 : de910000 r8 : c0107724
r7 : 00000081 r6 : bf001048 r5 : 000001d4 r4 : 00000000
r3 : bf000000 r2 : 00000000 r1 : 00000004 r0 : 000001d4
Flags: NzCv IRQs on FIQs on Mode SVC_32 ISA ARM Segment none
Control: 10c53c7d Table: 3d57c059 DAC: 00000051
Process rmmod (pid: 1334, stack limit = 0xde910208)
Stack: (0xde911f00 to 0xde912000)
1f00: bf000000 00000000 df5c7e10 bf000010 bf000000 df5c7e10 df5c7e10 c0351ca8
1f20: c0351c84 df5c7e10 bf001048 c0350734 bf001048 df5c7e10 df5c7e44 c035087c
1f40: bf001048 7f62dd4c 00000800 c034fb30 bf0010c0 c0158ee8 de910000 31397461
1f60: 6d61735f 32643561 6364615f 00000000 de911f90 de910000 de910000 00000000
1f80: de911fb0 10c53c7d de911f9c c05f33d8 de911fa0 00910000 be898ecb 7f62dd10
1fa0: 00000000 c0107560 be898ecb 7f62dd10 7f62dd4c 00000800 6f844800 6f844800
1fc0: be898ecb 7f62dd10 00000000 00000081 00000000 7f62dd10 be898bd8 be898bd8
1fe0: b6eedab1 be898b6c 7f61056b b6eedab6 000d0030 7f62dd4c 00000000 00000000
[<c05f4624>] (mutex_lock) from [<c0471f74>] (iio_device_unregister+0x14/0x6c)
[<c0471f74>] (iio_device_unregister) from [<bf000010>] (at91_adc_remove+0x10/0x3c [at91_sama5d2_adc])
[<bf000010>] (at91_adc_remove [at91_sama5d2_adc]) from [<c0351ca8>] (platform_drv_remove+0x24/0x3c)
[<c0351ca8>] (platform_drv_remove) from [<c0350734>] (__device_release_driver+0x84/0x110)
[<c0350734>] (__device_release_driver) from [<c035087c>] (driver_detach+0x8c/0x90)
[<c035087c>] (driver_detach) from [<c034fb30>] (bus_remove_driver+0x4c/0xa0)
[<c034fb30>] (bus_remove_driver) from [<c0158ee8>] (SyS_delete_module+0x110/0x1d0)
[<c0158ee8>] (SyS_delete_module) from [<c0107560>] (ret_fast_syscall+0x0/0x3c)
Code: e3520001 1affffd5 eafffff4 f5d0f000 (e1902f9f)
---[ end trace 86914d7ad3696fca ]---

Signed-off-by: Marek Vasut <marex@denx.de>
Cc: Ludovic Desroches <ludovic.desroches@atmel.com>
Cc: <Stable@vger.kernel.org>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

iio:adc:at91-sama5d2: add support for differential conversions

Add signed differential channels and update the voltage scale for
differential conversions.

Signed-off-by: Ludovic Desroches <ludovic.desroches@atmel.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

iio:adc:at91-sama5d2: cleanup mode register use

Do not erase previous configuration of the mode register when setting
the sampling frequency.

Signed-off-by: Ludovic Desroches <ludovic.desroches@atmel.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

iio:adc:at91-sama5d2: fix identation

Remove some extra tabs.

Signed-off-by: Ludovic Desroches <ludovic.desroches@atmel.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

iio:adc:at91-sama5d2: fix typo

Fix typo in the name of a macro.

Signed-off-by: Ludovic Desroches <ludovic.desroches@atmel.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

iio:adc:at91-sama5d2: code cleanup

Use var type for sizeof argument instead of the struct name.

Signed-off-by: Ludovic Desroches <ludovic.desroches@atmel.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

iio:adc:at91-sama5d2: fix vref_uv type

vref_uv has to be an int.

Signed-off-by: Ludovic Desroches <ludovic.desroches@atmel.com>
Reported-by: Julia Lawall <julia.lawall@lip6.fr>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

iio:adc:at91_adc8xx: introduce new atmel adc driver

This driver supports the new version of the Atmel ADC device introduced
with the SAMA5D2 SoC family.

Signed-off-by: Ludovic Desroches <ludovic.desroches@atmel.com>
Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>