The Qualcomm PM8xxx PMICs contain a simpler ADC than its
successors (already in the kernel as qcom-spmi-vadc.c):
the HK/XO ADC (Housekeeping/Chrystal oscillator ADC).

As far as I can understand this is equal to the PMICs
using SSBI transport and encompass PM8018, PM8038,
PM8058, and PM8921, so this is shortly named PM8xxx.

This ADC monitors a bunch of on-board voltages and the die
temperature of the PMIC itself, but it can also be routed
to convert a few external MPPs (multi-purpose pins). On
the APQ8060 DragonBoard this feature is used to let this
ADC convert an analog ALS (Ambient Light Sensor) voltage
signal from a Capella CM3605 ALS into a LUX value.

Developed and tested with APQ8060 DragonBoard based on
Ivan's driver and Rama Krishna's patches. The SPMI VADC
driver is quite different, but share enough minor
functionality that I have split out to the common file
in a previous patch.

Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-arm-msm@vger.kernel.org
Cc: Ivan T. Ivanov <iivanov.xz@gmail.com>
Cc: Andy Gross <andy.gross@linaro.org>
Cc: Bjorn Andersson <bjorn.andersson@linaro.org>
Cc: Stephen Boyd <sboyd@codeaurora.org>
Cc: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Cc: Rama Krishna Phani A <rphani@codeaurora.org>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>
Signed-off-by: NJonathan Cameron <jic23@kernel.org>

The SPMI VADC and the earlier XOADC share a subset of
common code, so to be able to use the same code in both
drivers, we break out a separate file with the common code,
prefix exported functions that are no longer static with
qcom_* and bake an object qcom-spmi-vadc.o that contains both
files: qcom-vadc-common.o and qcom-spmi-vadc-core.o.

As we need to follow the procedure for making a kernel module
or compiled in object from several files, but still want to
produce the same module name, rename the qcom-spmi-vadc.c
file to qcom-spmi-vadc-core.c so we can bake the two objects
into qcom-spmi-vadc.o

Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-arm-msm@vger.kernel.org
Cc: Ivan T. Ivanov <iivanov.xz@gmail.com>
Cc: Andy Gross <andy.gross@linaro.org>
Cc: Bjorn Andersson <bjorn.andersson@linaro.org>
Cc: Stephen Boyd <sboyd@codeaurora.org>
Cc: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Cc: Rama Krishna Phani A <rphani@codeaurora.org>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>
Signed-off-by: NJonathan Cameron <jic23@kernel.org>

This adds support for the Allwinner A33 thermal sensor.

Unlike the A10, A13 and A31, the Allwinner A33 only has one channel
which is dedicated to the thermal sensor. Moreover, its thermal sensor
does not generate interruptions, thus we only need to directly read the
register storing the temperature value.

The MFD used by the A10, A13 and A31, was created to avoid breaking the
DT binding, but since the nodes for the ADC weren't there for the A33,
it is not needed.

Though the A33 does not have an internal ADC, it has a thermal sensor
which shares the same registers with GPADC of the already supported SoCs
and almost the same bits, for the same purpose (thermal sensor).

The thermal sensor behaves exactly the same (except the presence of
interrupts or not) on the different SoCs.
Signed-off-by: NQuentin Schulz <quentin.schulz@free-electrons.com>
Acked-by: NLee Jones <lee.jones@linaro.org>
Signed-off-by: NJonathan Cameron <jic23@kernel.org>

This moves code used in MFD probing to a new sun4i_gpadc_probe_mfd
function.

This driver was initially written for A10, A13 and A31 SoCs which
already had a DT binding for this IP, thus we needed to use an MFD to
probe the different drivers without changing the DT binding of these
SoCs.

For SoCs that will require to create a DT binding for this IP, we can
avoid using an MFD, thus we need two separate functions: one for probing
via MFD and one for probing without MFD.

This split the code specific to MFD probing in a function separated from
the driver probe function.
Signed-off-by: NQuentin Schulz <quentin.schulz@free-electrons.com>
Signed-off-by: NJonathan Cameron <jic23@kernel.org>

Add iio driver for Maxim max9611 and max9612 current-sense amplifiers
with 12-bits ADC interface.

Datasheet publicly available at:
https://datasheets.maximintegrated.com/en/ds/MAX9611-MAX9612.pdfSigned-off-by: NJacopo Mondi <jacopo+renesas@jmondi.org>
Signed-off-by: NJonathan Cameron <jic23@kernel.org>

stm32 adc supports several resolution. Add 'assigned-resolution-bits'
dt optional property to set it. Default to maximum resolution in case
it isn't set.
Signed-off-by: NFabrice Gasnier <fabrice.gasnier@st.com>
Signed-off-by: NJonathan Cameron <jic23@kernel.org>

With CONFIG_THERMAL=m and CONFIG_SUN4I_GPADC=y, we get a link error
from calling devm_thermal_zone_of_sensor_register:

drivers/iio/built-in.o: In function `sun4i_gpadc_probe':
:(.text+0x1c284): undefined reference to `devm_thermal_zone_of_sensor_register'

This adds a Kconfig dependency to ensure we can only have the ADC
driver as built-in when this function is also built-in, or when
we see the empty stub implementation. When the thermal code is
a module, we can still build the adc driver as a module, too.
Signed-off-by: NArnd Bergmann <arnd@arndb.de>
Fixes: d1caa990 ("iio: adc: add support for Allwinner SoCs ADC")
Signed-off-by: NJonathan Cameron <jic23@kernel.org>

This patch adds support for the Analog Devices / Linear Technology
LTC2497 ADCs. The LTC2497 is a 16-channel (eight differential),
16-bit, high precision, delta-sigma ADC with an automatic, differential,
input current cancellation front end and a 2-wire, I2C interface.
Signed-off-by: NMichael Hennerich <michael.hennerich@analog.com>
Signed-off-by: NJonathan Cameron <jic23@kernel.org>

The following Coccinelle script was used to detect this:
@r@
expression x;
void* e;
type T;
identifier f;
@@
(
  *((T *)e)
|
  ((T *)x)[...]
|
  ((T*)x)->f
|
- (T*)
  e
)
Signed-off-by: Nsimran singhal <singhalsimran0@gmail.com>
Signed-off-by: NJonathan Cameron <jic23@kernel.org>

Aspeed BMC SoCs include a 16 channel, 10-bit ADC. Low and high threshold
interrupts are supported by the hardware but are not currently implemented.
Signed-off-by: NRick Altherr <raltherr@google.com>
Tested-by: NXo Wang <xow@google.com>
Reviewed-by: NJoel Stanley <joel@jms.id.au>
Signed-off-by: NJonathan Cameron <jic23@kernel.org>

Check for attribute_group structures that are only stored in the
attrs filed of iio_info structure. As the attrs field of iio_info
structures is constant, so these attribute_group structures can also be
declared constant.
Done using coccinelle:

@r1 disable optional_qualifier @
identifier i;
position p;
@@
static struct attribute_group i@p = {...};

@ok1@
identifier r1.i;
position p;
struct iio_info x;
@@
x.attrs=&i@p;

@bad@
position p!={r1.p,ok1.p};
identifier r1.i;
@@
i@p

@depends on !bad disable optional_qualifier@
identifier r1.i;
@@
static
+const
struct attribute_group i={...};

@depends on !bad disable optional_qualifier@
identifier r1.i;
@@
+const
struct attribute_group i;

File size before:
   text	   data	    bss	    dec	    hex	filename
   3042	    480	      0	   3522	    dc2	drivers/iio/adc/hx711.o

File size after:
   text	   data	    bss	    dec	    hex	filename
   3098	    416	      0	   3514	    dba	drivers/iio/adc/hx711.o
Signed-off-by: Nsimran singhal <singhalsimran0@gmail.com>
Signed-off-by: NJonathan Cameron <jic23@kernel.org>

On Motorola phones like droid 4 there is a custom CPCAP PMIC. This PMIC
has ADCs that are used for battery charging and USB PHY VBUS and ID pin
detection.

Unfortunately the only documentation for this ADC seems to be the
Motorola mapphone Linux kernel tree. I have tested that reading raw and
scaled values works, but I have not used the timed sampling that the ADC
seems to support.

Let's add a minimal support for it so we can eventually provide IIO
channels for the related battery charging and USB PHY drivers.

Cc: devicetree@vger.kernel.org
Cc: Marcel Partap <mpartap@gmx.net>
Cc: Michael Scott <michael.scott@linaro.org>
Cc: Sebastian Reichel <sre@kernel.org>
Signed-off-by: NTony Lindgren <tony@atomide.com>
Acked-by: NRob Herring <robh@kernel.org>
Signed-off-by: NJonathan Cameron <jic23@kernel.org>

Replace a comma between expression statements by a semicolon. This
changes the semantics of the code, but given the current indentation
appears to be what is intended.
A simplified version of the Coccinelle semantic patch that performs this
transformation is as follows:

// <smpl>
@r@
expression e1,e2;
@@

 e1
-,
+;
 e2;
// </smpl>
Signed-off-by: NArushi Singhal <arushisinghal19971997@gmail.com>
Signed-off-by: NJonathan Cameron <jic23@kernel.org>

Check for attribute_group structures that are only stored in the
event_attrs filed of iio_info structure. As the event_attrs field of
iio_info structures is constant, so these attribute_group structures can
also be declared constant.
Done using coccinelle:

@r1 disable optional_qualifier @
identifier i;
position p;
@@
static struct attribute_group i@p = {...};

@ok1@
identifier r1.i;
position p;
struct iio_info x;
@@
x.event_attrs=&i@p;

@bad@
position p!={r1.p,ok1.p};
identifier r1.i;
@@
i@p

@depends on !bad disable optional_qualifier@
identifier r1.i;
@@
static
+const
struct attribute_group i={...};

@depends on !bad disable optional_qualifier@
identifier r1.i;
@@
+const
struct attribute_group i;

File size before:
   text    data     bss     dec     hex filename
  26051     464       0   26515    6793 drivers/iio/adc/ad799x.o

File size after:
   text	   data	    bss	    dec	    hex	filename
  26115	    400	      0	  26515	   6793	drivers/iio/adc/ad799x.o
Signed-off-by: Nsimran singhal <singhalsimran0@gmail.com>
Signed-off-by: NJonathan Cameron <jic23@kernel.org>

Check for attribute_group structures that are only stored in the
event_attrs filed of iio_info structure. As the event_attrs field of
iio_info structures is constant, so these attribute_group structures can
also be declared constant. Done using coccinelle:

@r1 disable optional_qualifier @
identifier i;
position p;
@@
static struct attribute_group i@p = {...};

@ok1@
identifier r1.i;
position p;
struct iio_info x;
@@
x.event_attrs=&i@p;

@bad@
position p!={r1.p,ok1.p};
identifier r1.i;
@@
i@p

@depends on !bad disable optional_qualifier@
identifier r1.i;
@@
static
+const
struct attribute_group i={...};

@depends on !bad disable optional_qualifier@
identifier r1.i;
@@
+const
struct attribute_group i;

File size before:
   text    data     bss     dec     hex filename
  36951     448       0   37399    9217 drivers/iio/adc/max1363.o

File size after:
   text	   data	    bss	    dec	    hex	filename
  37015	    384	      0	  37399	   9217	drivers/iio/adc/max1363.o
Signed-off-by: Nsimran singhal <singhalsimran0@gmail.com>
Signed-off-by: NJonathan Cameron <jic23@kernel.org>

This patch adds calibration for the Meson SAR ADC.
Points 25% vref and 75% vref are used for calibration.
It uses a simple linear calibration function: SCALE * val + BIAS

Successfully tested on a Odroid C2.
Signed-off-by: NHeiner Kallweit <hkallweit1@gmail.com>
Tested-by: NMartin Blumenstingl <martin.blumenstingl@googlemail.com>
Reviewed-by: NMartin Blumenstingl <martin.blumenstingl@googlemail.com>
Signed-off-by: NJonathan Cameron <jic23@kernel.org>

The driver doesn't have a struct of_device_id table but supported devices
are registered via Device Trees. This is working on the assumption that a
I2C device registered via OF will always match a legacy I2C device ID and
that the MODALIAS reported will always be of the form i2c:<device>.

But this could change in the future so the correct approach is to have an
OF device ID table if the devices are registered via OF.
Signed-off-by: NJavier Martinez Canillas <javier@osg.samsung.com>
Signed-off-by: NJonathan Cameron <jic23@kernel.org>

The driver doesn't have a struct of_device_id table but supported devices
are registered via Device Trees. This is working on the assumption that a
I2C device registered via OF will always match a legacy I2C device ID and
that the MODALIAS reported will always be of the form i2c:<device>.

But this could change in the future so the correct approach is to have an
OF device ID table if the devices are registered via OF.
Signed-off-by: NJavier Martinez Canillas <javier@osg.samsung.com>
Signed-off-by: NJonathan Cameron <jic23@kernel.org>

PC/104 drivers should be hidden on machines which do not support PC/104
devices. This patch adds the PC104 Kconfig option as a dependency for
the relevant PC/104 device driver Kconfig options.

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>
Signed-off-by: NWilliam Breathitt Gray <vilhelm.gray@gmail.com>
Signed-off-by: NJonathan Cameron <jic23@kernel.org>

The tiadc_irq_h(int irq, void *private) function is handling FIFO
overruns by clearing flags, disabling and enabling the ADC to
recover.

If the ADC is running in continuous mode a FIFO overrun happens
regularly. If the disabling of the ADC happens concurrently with
a new conversion. It might happen that the enabling of the ADC
is ignored by the hardware. This stops the ADC permanently. No
more interrupts are triggered.

According to the AM335x Reference Manual (SPRUH73H October 2011 -
Revised April 2013 - Chapter 12.4 and 12.5) it is necessary to
check the ADC FSM bits in REG_ADCFSM before enabling the ADC
again. Because the disabling of the ADC is done right after the
current conversion has been finished.

To trigger this bug it is necessary to run the ADC in continuous
mode. The ADC values of all channels need to be read in an endless
loop. The bug appears within the first 6 hours (~5.4 million
handled FIFO overruns). The user space application will hang on
reading new values from the character device.

Fixes: ca9a5638 ("iio: ti_am335x_adc: Add continuous sampling
support")
Signed-off-by: NMichael Engl <michael.engl@wjw-solutions.com>
Cc: <Stable@vger.kernel.org>
Signed-off-by: NJonathan Cameron <jic23@kernel.org>

The Allwinner SoCs all have an ADC that can also act as a touchscreen
controller and a thermal sensor. This patch adds the ADC driver which is
based on the MFD for the same SoCs ADC.

This also registers the thermal adc channel in the iio map array so
iio_hwmon could use it without modifying the Device Tree. This registers
the driver in the thermal framework.

The thermal sensor requires the IP to be in touchscreen mode to return
correct values. Therefore, if the user is continuously reading the ADC
channel(s), the thermal framework in which the thermal sensor is
registered will switch the IP in touchscreen mode to get a temperature
value and requires a delay of 100ms (because of the mode switching),
then the ADC will switch back to ADC mode and requires also a delay of
100ms. If the ADC readings are critical to user and the SoC temperature
is not, this driver is capable of not registering the thermal sensor in
the thermal framework and thus, "quicken" the ADC readings.

This driver probes on three different platform_device_id to take into
account slight differences (registers bit and temperature computation)
between Allwinner SoCs ADCs.
Signed-off-by: NQuentin Schulz <quentin.schulz@free-electrons.com>
Acked-by: NMaxime Ripard <maxime.ripard@free-electrons.com>
Acked-by: NJonathan Cameron <jic23@kernel.org>
Acked-for-MFD-by: NLee Jones <lee.jones@linaro.org>
Signed-off-by: NJonathan Cameron <jic23@kernel.org>

Remove .owner field if calls are used which set it automatically.

Generated by: scripts/coccinelle/api/platform_no_drv_owner.cocci
Signed-off-by: NWei Yongjun <weiyongjun1@huawei.com>
Signed-off-by: NJonathan Cameron <jic23@kernel.org>

Reorder error handling labels in order to match the way resources have
been allocated.
Signed-off-by: NChristophe JAILLET <christophe.jaillet@wanadoo.fr>
Acked-by: NLars-Peter Clausen <lars@metafoo.de>
Signed-off-by: NJonathan Cameron <jic23@kernel.org>

After sampling there should always be only one value in the FIFO.
This also applies to averaging mode as the averaging is done
chip-internally. So we don't have to loop and let the driver
complain if there's not exactly one value in the FIFO.

If the value belongs to a different channel then don't silently
swallow the value but complain.
Signed-off-by: NHeiner Kallweit <hkallweit1@gmail.com>
Acked-by: NMartin Blumenstingl <martin.blumenstingl@googlemail.com>
Signed-off-by: NJonathan Cameron <jic23@kernel.org>

Switch from polling to interrupt mode.

Successfully tested on a S905GXBB-based Odroid C2.
Signed-off-by: NHeiner Kallweit <hkallweit1@gmail.com>
Acked-by: NMartin Blumenstingl <martin.blumenstingl@googlemail.com>
Tested-by: NMartin Blumenstingl <martin.blumenstingl@googlemail.com>
Signed-off-by: NJonathan Cameron <jic23@kernel.org>

Initialize the parent of the IIO device to the device that registered it.
This makes sure that the IIO device appears the right level in the device
hierarchy.
Signed-off-by: NLars-Peter Clausen <lars@metafoo.de>
Acked-by: William Breathitt Gray <vilhelm.gray@gmail.com
Signed-off-by: NJonathan Cameron <jic23@kernel.org>

There are a few more little cleanups that could be done on this driver, but
I don't think any are sufficient to justify not moving it out of staging.

It's a very simple driver (presumably for a simple part) so not much that can
go wrong.  I think it was only ever in staging because that's where IIO was
as a whole at the time and then we forgot about it!
Signed-off-by: NJonathan Cameron <jic23@kernel.org>
Cc: Roland Stigge <stigge@antcom.de>
Signed-off-by: NJonathan Cameron <jic23@kernel.org>

There are some unanswered questions due to disagreements between the code
and various datasheets (including between different datasheets for the same
part).

I don't think that is necessarily a reason to keep it in staging however.
I'm partly posting this patch inorder to reignite debate and with a bit
of luck find someone who has one of these to test!
Signed-off-by: NJonathan Cameron <jic23@kernel.org>

If we get an unknown 'childmode' value, a number of variables are not
initialized properly:

drivers/iio/adc/rcar-gyroadc.c: In function 'rcar_gyroadc_probe':
drivers/iio/adc/rcar-gyroadc.c:390:5: error: 'num_channels' may be used uninitialized in this function [-Werror=maybe-uninitialized]
drivers/iio/adc/rcar-gyroadc.c:426:22: error: 'sample_width' may be used uninitialized in this function [-Werror=maybe-uninitialized]
drivers/iio/adc/rcar-gyroadc.c:428:23: error: 'channels' may be used uninitialized in this function [-Werror=maybe-uninitialized]

The driver is currently correct, but handling this properly is more robust
for possible modifications.

There is also a false-positive warning about adcmode being possibly uninitialized,
but that cannot happen as we also check the 'first' flag:

drivers/iio/adc/rcar-gyroadc.c:398:26: error: 'adcmode' may be used uninitialized in this function [-Werror=maybe-uninitialized]

This adds an initialization for 'adcmode' and bails out for any unknown childmode.

Fixes: 059c53b3 ("iio: adc: Add Renesas GyroADC driver")
Signed-off-by: NArnd Bergmann <arnd@arndb.de>
Acked-by: NMarek Vasut <marek.vasut@gmail.com>
Signed-off-by: NJonathan Cameron <jic23@kernel.org>

The Apex Embedded Systems STX104 series provides a digital output
register where 4 lines may be set at a time. This patch add support for
the set_multiple callback function, thus allowing multiple digital
output lines to be set more efficiently in groups.

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>
Signed-off-by: NWilliam Breathitt Gray <vilhelm.gray@gmail.com>
Signed-off-by: NJonathan Cameron <jic23@kernel.org>

This patch sets the gpio_chip names option with an array of GPIO line
names that match the manual documentation for the Apex Embedded Systems
STX104. This should make it easier for users to identify which GPIO line
corresponds to a respective GPIO pin on the device.
Signed-off-by: NWilliam Breathitt Gray <vilhelm.gray@gmail.com>
Reviewed-by: NLinus Walleij <linus.walleij@linaro.org>
Signed-off-by: NJonathan Cameron <jic23@kernel.org>

The stx104_dev structure was used to hold private data for use in the
stx104_remove function. Now that the stx104_remove function is gone, the
stx104_dev structure and relevant code is no longer needed. This patch
removes the unnecessary code.
Signed-off-by: NWilliam Breathitt Gray <vilhelm.gray@gmail.com>
Signed-off-by: NJonathan Cameron <jic23@kernel.org>

Add DMA optional support to STM32 ADC, as there is a limited number DMA
channels (request lines) that can be assigned to ADC. This way, driver
may fall back using interrupts when all DMA channels are in use for
other IPs.
Use dma cyclic mode with two periods. Allow to tune period length by
using watermark. Coherent memory is used for dma (max buffer size is
fixed to PAGE_SIZE).
Signed-off-by: NFabrice Gasnier <fabrice.gasnier@st.com>
Signed-off-by: NJonathan Cameron <jic23@kernel.org>

Define extended attribute so that user may choose rising, falling or both
edges for external trigger sources.
Default to rising edge in case it isn't set.
Signed-off-by: NFabrice Gasnier <fabrice.gasnier@st.com>
Signed-off-by: NJonathan Cameron <jic23@kernel.org>

STM32 ADC has external timer trigger sources. Use stm32 timer triggers
API (e.g. is_stm32_timer_trigger()) with local ADC lookup table to
validate a trigger can be used.
This also provides correct trigger selection value (e.g. extsel).
Signed-off-by: NFabrice Gasnier <fabrice.gasnier@st.com>
Signed-off-by: NJonathan Cameron <jic23@kernel.org>

STM32 ADC conversions can be launched using hardware triggers.
It can be used to start conversion sequences (group of channels).
Selected channels are select via sequence registers.
Trigger source is selected via 'extsel' (external trigger mux).
Trigger polarity is set to rising edge by default.
Signed-off-by: NFabrice Gasnier <fabrice.gasnier@st.com>
Signed-off-by: NJonathan Cameron <jic23@kernel.org>

The devm_ resource manager functions allow memory to be automatically
released when a device is unbound. This patch takes advantage of the
resource manager functions and replaces the gpiochip_add_data call and
iio_device_register call with the devm_gpiochip_add_data call and
devm_iio_device_register call respectively. In addition, the
stx104_remove function has been removed as no longer necessary due to
the use of the relevant devm_ resource manager functions.
Signed-off-by: NWilliam Breathitt Gray <vilhelm.gray@gmail.com>
Signed-off-by: NJonathan Cameron <jic23@kernel.org>

This adds support for the SAR (Successive Approximation Register) ADC
on the Amlogic Meson SoCs.

The code is based on the public S805 (Meson8b) and S905 (GXBB)
datasheets (see [0] and [1]), as well as by reading (various versions
of) the vendor driver and by inspecting the registers on the vendor
kernels of my testing-hardware.

Currently the GXBB, GXL and GXM SoCs are supported. GXBB hardware has
10-bit ADC resolution, while GXL and GXM have 12-bit ADC resolution.
The code was written to support older SoCs (Meson8 and Meson8b) as well,
but due to lack of actual testing-hardware no of_device_id was added for
these.

Two "features" from the vendor driver are currently missing:
- the vendor driver uses channel #7 for calibration (this improves the
  accuracy of the results - in my tests the results were less than 3%
  off without calibration compared to the vendor driver). Adding support
  for this should be easy, but is not required for most applications.
- channel #6 is connected to the SoCs internal temperature sensor.
  Adding support for this is probably not so easy since (based on the
  u-boot sources) most SoC versions are using different registers and
  algorithms for the conversion from "ADC value" to temperature.

Supported by the hardware but currently not supported by the driver:
- reading multiple channels at the same time (the hardware has a FIFO
  buffer which stores multiple results)
- continuous sampling (this would require a way to enable this
  individually because otherwise the ADC would be drawing power
  constantly)
- interrupt support (similar to the vendor driver this new driver is
  polling the results. It is unclear if the IRQ-mode is supported on
  older (Meson6 or Meson8) hardware as well or if there are any errata)

[0]
http://dn.odroid.com/S805/Datasheet/S805_Datasheet%20V0.8%2020150126.pdf
[1] http://dn.odroid.com/S905/DataSheet/S905_Public_Datasheet_V1.1.4.pdfSigned-off-by: NMartin Blumenstingl <martin.blumenstingl@googlemail.com>
Tested-by: NNeil Armstrong <narmstrong@baylibre.com>
Signed-off-by: NJonathan Cameron <jic23@kernel.org>

Add IIO driver for the Renesas RCar GyroADC block. This block is a
simple 4/8-channel ADC which samples 12/15/24 bits of data every
cycle from all channels.
Signed-off-by: NMarek Vasut <marek.vasut+renesas@gmail.com>
Cc: Geert Uytterhoeven <geert+renesas@glider.be>
Cc: Simon Horman <horms+renesas@verge.net.au>
Cc: Jonathan Cameron <jic23@kernel.org>
Cc: linux-renesas-soc@vger.kernel.org
Cc: Wolfram Sang <wsa@the-dreams.de>
Signed-off-by: NJonathan Cameron <jic23@kernel.org>

Declare iio_info structures as const as they are only stored in
the info field of a iio_dev structure. This field is of type const,
so iio_info structures having similar properties can be made const too.

File size before:
   text	   data	    bss	    dec	    hex	filename
   6944	    792	      0	   7736	   1e38	drivers/iio/adc/ti-ads1015.o

File size after:
   text   data	    bss	    dec	    hex	filename
   7264	    472	      0	   7736	   1e38	drivers/iio/adc/ti-ads1015.o
Signed-off-by: NBhumika Goyal <bhumirks@gmail.com>
Signed-off-by: NJonathan Cameron <jic23@kernel.org>