iio: Use device_get_match_data()

Use preferred device_get_match_data() instead of of_match_device() to
get the driver match data. With this, adjust the includes to explicitly
include the correct headers.

Signed-off-by: Rob Herring <robh@kernel.org>
Link: https://lore.kernel.org/r/20231006224440.442864-1-robh@kernel.org
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: adc: stm32-adc-core: 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/20230919174931.1417681-21-u.kleine-koenig@pengutronix.de
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: adc: stm32-adc: harden against NULL pointer deref in stm32_adc_probe()

of_match_device() may fail and returns a NULL pointer.

In practice there is no known reasonable way to trigger this, but
in case one is added in future, harden the code by adding the check

Signed-off-by: Zhang Shurong <zhang_shurong@foxmail.com>
Link: https://lore.kernel.org/r/tencent_994DA85912C937E3B5405BA960B31ED90A08@qq.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: adc: Explicitly include correct DT includes

The DT of_device.h and of_platform.h date back to the separate
of_platform_bus_type before it as merged into the regular platform bus.
As part of that merge prepping Arm DT support 13 years ago, they
"temporarily" include each other. They also include platform_device.h
and of.h. As a result, there's a pretty much random mix of those include
files used throughout the tree. In order to detangle these headers and
replace the implicit includes with struct declarations, users need to
explicitly include the correct includes.

Signed-off-by: Rob Herring <robh@kernel.org>
Acked-by: Heiko Stuebner <heiko@sntech.de>
Link: https://lore.kernel.org/r/20230714174628.4057920-1-robh@kernel.org
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: adc: stm32-adc: Use devm_platform_get_and_ioremap_resource()

Convert platform_get_resource(), devm_ioremap_resource() to a single
call to devm_platform_get_and_ioremap_resource(), as this is exactly
what this function does.

Signed-off-by: Yangtao Li <frank.li@vivo.com>
Link: https://lore.kernel.org/r/20230704095808.33780-1-frank.li@vivo.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: adc: stm32-adc: add stm32mp13 support

Add STM32 ADC support for STM32MP13x SOCs family.

On STM32MP13x, each ADC peripheral has a single ADC block.
These ADC peripherals, ADC1 and ADC2, are fully independent.
This introduces changes in common registers handling.

Some features such as boost mode, channel preselection and
linear calibration are not supported by the STM32MP13x ADC.
Add diversity management for these features.

The STM32MP13x ADC introduces registers and bitfield variants
on existing features such as calibration factors and internal
channels. Add register diversity management.

Add also support for new internal channels VDDCPU and VDDQ_DDR.

Signed-off-by: Olivier Moysan <olivier.moysan@foss.st.com>
Reviewed-by: Fabrice Gasnier <fabrice.gasnier@foss.st.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Link: https://lore.kernel.org/r/20221012142205.13041-4-olivier.moysan@foss.st.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: adc: stm32-adc: add id registers support

Add support of identification registers to STM32 ADC.

By default the ADC hardware instance number is retrieved from
the compatible configuration data. Get the available ADC number
per ADC block, from hardware configuration register,
when this register exists.

Signed-off-by: Olivier Moysan <olivier.moysan@foss.st.com>
Reviewed-by: Fabrice Gasnier <fabrice.gasnier@foss.st.com>
Link: https://lore.kernel.org/r/20220915135452.1712453-1-olivier.moysan@foss.st.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: adc: stm32-adc: Use generic_handle_domain_irq()

The call chain
generic_handle_irq(irq_find_mapping(domain, x));

could be replaced with
generic_handle_domain_irq(domain, x);

which looks up the struct irq_desc for the interrupt and handles it with
handle_irq_desc().
This is a slight optimisation given that the driver invokes only one
function and the struct irq_desc is used directly instead being looked
up via irq_to_desc().

Use generic_handle_domain_irq().

Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Link: https://lore.kernel.org/r/YnuYoQIzJoFIyEJY@linutronix.de
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: adc: stm32: fix maximum clock rate for stm32mp15x

Change maximum STM32 ADC input clock rate to 36MHz, as specified
in STM32MP15x datasheets.

Fixes: d58c67d1d851 ("iio: adc: stm32-adc: add support for STM32MP1")
Signed-off-by: Olivier Moysan <olivier.moysan@foss.st.com>
Reviewed-by: Fabrice Gasnier <fabrice.gasnier@foss.st.com>
Link: https://lore.kernel.org/r/20220609095234.375925-1-olivier.moysan@foss.st.com
Cc: <Stable@vger.kernel.org>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: adc: stm32: Fix ADCs iteration in irq handler

The irq handler was only checking the mask for the first ADCs in the case of the
F4 and H7 generation, since it was iterating up to the num_irq value. This patch add
the maximum number of ADC in the common register, which map to the number of entries of
eoc_msk and ovr_msk in stm32_adc_common_regs. This allow the handler to check all ADCs in
that module.

Tested on a STM32F429NIH6.

Fixes: 695e2f5c289b ("iio: adc: stm32-adc: fix a regression when using dma and irq")
Signed-off-by: Yannick Brosseau <yannick.brosseau@gmail.com>
Reviewed-by: Fabrice Gasnier <fabrice.gasnier@foss.st.com>
Link: https://lore.kernel.org/r/20220516203939.3498673-2-yannick.brosseau@gmail.com
Cc: <Stable@vger.kernel.org>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio:adc:stm32:Switch from CONFIG_PM guards to pm_ptr()

Letting the compiler remove these functions when the kernel is built
without CONFIG_PM support is simpler and less error prone than the
use of #ifdef based config guards.

Removing instances of this approach from IIO also stops them being
copied into new drivers.

The new DEFINE_RUNTIME_DEV_PM_OPS() macro reduces boilerplate.

Reviewed-by: Fabrice Gasnier <fabrice.gasnier@foss.st.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Cc: Olivier Moysan <olivier.moysan@foss.st.com>
Reviewed-by: Paul Cercueil <paul@crapouillou.net>
Link: https://lore.kernel.org/r/20220130193147.279148-45-jic23@kernel.org

iio: adc: stm32-adc: add support of internal channels

Add support of ADC2 internal channels VDDCORE, VREFINT and VBAT.
The reserved label name "vddcore", "vrefint" and "vbat" must
be used in Device Tree channel node, to enable the corresponding
internal channel.

Note: This patch does not provide support of internal channels
for F4 and H7.

Signed-off-by: Olivier Moysan <olivier.moysan@foss.st.com>
Reviewed-by: Fabrice Gasnier <fabrice.gasnier@foss.st.com>
Link: https://lore.kernel.org/r/20211014131228.4692-6-olivier.moysan@foss.st.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: adc: stm32-adc: Remove redundant null check before clk_prepare_enable/clk_disable_unprepare

Because clk_prepare_enable() and clk_disable_unprepare() already checked
NULL clock parameter, so the additional checks are unnecessary, just
remove them.

Signed-off-by: Xu Wang <vulab@iscas.ac.cn>
Acked-by: Fabrice Gasnier <fabrice.gasnier@foss.st.com>
Link: https://lore.kernel.org/r/20201218093512.871-1-vulab@iscas.ac.cn
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: adc: stm32-adc: adapt clock duty cycle for proper operation

For proper operation, STM32 ADC should be used with a clock duty cycle
of 50%, in the range of 49% to 51%. Depending on the clock tree, divider
can be used in case clock duty cycle is out of this range.
In case clk_get_scaled_duty_cycle() returns an error, kindly apply a
divider by default (don't make the probe fail).

Signed-off-by: Fabrice Gasnier <fabrice.gasnier@st.com>
Link: https://lore.kernel.org/r/1604681846-31234-1-git-send-email-fabrice.gasnier@st.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: adc: stm32-adc: fix a regression when using dma and irq

Since overrun interrupt support has been added, there's a regression when
two ADCs are used at the same time, with:
- an ADC configured to use IRQs. EOCIE bit is set. The handler is normally
called in this case.
- an ADC configured to use DMA. EOCIE bit isn't set. EOC triggers the DMA
request. It's then automatically cleared by DMA read. But the handler
gets called due to status bit is temporarily set (IRQ triggered by the
other ADC).

This is a regression as similar issue had been fixed earlier by
commit dcb10920179a ("iio: adc: stm32-adc:
fix a race when using several adcs with dma and irq").
Issue is that stm32_adc_eoc_enabled() returns non-zero value (always)
since OVR bit has been added and enabled for both DMA and IRQ case.

Remove OVR mask in IER register, and rely only on CSR status for overrun.
To avoid subsequent calls to interrupt routine on overrun, CSR OVR bit has
to be cleared. CSR OVR bit cannot be cleared directly by software.
To do this ADC must be stopped first, and OVR bit in ADC ISR has
to be cleared.
Also add a check in ADC IRQ handler to report spurious IRQs.

Fixes: cc06e67d8fa5 ("iio: adc: stm32-adc: Add check on overrun interrupt")
Signed-off-by: Olivier Moysan <olivier.moysan@st.com>
Signed-off-by: Fabrice Gasnier <fabrice.gasnier@st.com>
Cc: <Stable@vger.kernel.org>
Link: https://lore.kernel.org/r/20201021085313.5335-1-olivier.moysan@st.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: adc: stm32-adc: fix runtime autosuspend delay when slow polling

When the ADC is runtime suspended and starting a conversion, the stm32-adc
driver calls pm_runtime_get_sync() that gets cascaded to the parent
(e.g. runtime resume of stm32-adc-core driver). This also kicks the
autosuspend delay (e.g. 2s) of the parent.
Once the ADC is active, calling pm_runtime_get_sync() again (upon a new
capture) won't kick the autosuspend delay for the parent (stm32-adc-core
driver) as already active.

Currently, this makes the stm32-adc-core driver go in suspend state
every 2s when doing slow polling. As an example, doing a capture, e.g.
cat in_voltageY_raw at a 0.2s rate, the auto suspend delay for the parent
isn't refreshed. Once it expires, the parent immediately falls into
runtime suspended state, in between two captures, as soon as the child
driver falls into runtime suspend state:
- e.g. after 2s, + child calls pm_runtime_put_autosuspend() + 100ms
autosuspend delay of the child.
- stm32-adc-core switches off regulators, clocks and so on.
- They get switched on back again 100ms later in this example (at 2.2s).

So, use runtime_idle() callback in stm32-adc-core driver to call
pm_runtime_mark_last_busy() for the parent driver (stm32-adc-core),
to avoid this.

Fixes: 9bdbb1139ca1 ("iio: adc: stm32-adc: add power management support")
Signed-off-by: Fabrice Gasnier <fabrice.gasnier@st.com>
Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org>
Link: https://lore.kernel.org/r/1593615328-5180-1-git-send-email-fabrice.gasnier@st.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: adc: stm32: Fix missing return in booster error path

Conversion of error paths to dev_err_probe() dropped one return
statement. The driver will continue to probe if getting booster
regulator fails.

Fixes: ce30eeb613cb ("iio: adc: stm32: Simplify with dev_err_probe()")
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>
Link: https://lore.kernel.org/r/1599727927-7776-1-git-send-email-krzk@kernel.org
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: adc: stm32: Simplify with dev_err_probe()

Common pattern of handling deferred probe can be simplified with
dev_err_probe(). Less code and also it prints the error value.

Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Link: https://lore.kernel.org/r/20200829064726.26268-8-krzk@kernel.org
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: adc: stm32-adc: fix a wrong error message when probing interrupts

A wrong error message is printed out currently, like on STM32MP15:
- stm32-adc-core 48003000.adc: IRQ index 2 not found.

This is seen since commit 7723f4c5ecdb ("driver core: platform: Add an
error message to platform_get_irq*()").
The STM32 ADC core driver wrongly requests up to 3 interrupt lines. It
should request only the necessary IRQs, based on the compatible:
- stm32f4/h7 ADCs share a common interrupt
- stm32mp1, has one interrupt line per ADC.
So add the number of required interrupts to the compatible data.

Fixes: d58c67d1d851 ("iio: adc: stm32-adc: add support for STM32MP1")
Signed-off-by: Fabrice Gasnier <fabrice.gasnier@st.com>
Cc: <Stable@vger.kernel.org>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: adc: stm32-adc: don't print an error on probe deferral

Do not print an error trace when deferring probe for some resource.

Signed-off-by: Etienne Carriere <etienne.carriere@st.com>
Signed-off-by: Fabrice Gasnier <fabrice.gasnier@st.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: adc: stm32-adc: Add check on overrun interrupt

Enable overrun interrupt on STM32 ADC. In case data register hasn't been
read (by CPU or DMA), overrun condition is detected when there's new
conversion data available. Stop grabbing data and log an error message.
Use a threaded irq to avoid printing the error message from hard irq
context.

Signed-off-by: Fabrice Gasnier <fabrice.gasnier@st.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: adc: stm32: allow to tune analog clock

Add new optional dt property to tune analog clock prescaler.
Driver looks for optional "st,max-clk-rate-hz", then computes
best approximation below that rate, using ADC internal prescaler.

Signed-off-by: Fabrice Gasnier <fabrice.gasnier@st.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: adc: stm32-adc: fix kernel-doc warnings

Fix the following warnings when documentation is built:
drivers/iio/adc/stm32-adc-core.c:62: warning: cannot understand function
prototype: 'struct stm32_adc_common_regs '
drivers/iio/adc/stm32-adc-core.c:78: warning: cannot understand function
prototype: 'struct stm32_adc_priv_cfg '
drivers/iio/adc/stm32-adc-core.c:123: warning: Function parameter or
member 'pdev' not described in 'stm32f4_adc_clk_sel'
drivers/iio/adc/stm32-adc.c:219: warning: cannot understand function
prototype: 'struct stm32_adc_regs '
drivers/iio/adc/stm32-adc.c:237: warning: cannot understand function
prototype: 'struct stm32_adc_regspec '
drivers/iio/adc/stm32-adc.c:264: warning: cannot understand function
prototype: 'struct stm32_adc_cfg '
drivers/iio/adc/stm32-adc.c:323: warning: Function parameter or member
'difsel' not described in 'N'
drivers/iio/adc/stm32-adc.c:323: warning: Function parameter or member
'pcsel' not described in 'stm32_adc'
drivers/iio/adc/stm32-adc.c:371: warning: cannot understand function
prototype: 'const struct stm32_adc_regs stm32f4_sq[STM32_ADC_MAX_SQ + 1]
drivers/iio/adc/stm32-adc.c:417: warning: cannot understand function
prototype: 'const struct stm32_adc_regs stm32f4_smp_bits[] = '
drivers/iio/adc/stm32-adc.c:508: warning: cannot understand function
prototype: 'const struct stm32_adc_regs stm32h7_smp_bits[] = '
drivers/iio/adc/stm32-adc.c:1112: warning: Function parameter or member
'indio_dev' not described in 'stm32_adc_get_trig_extsel'
drivers/iio/adc/stm32-adc.c:1420: warning: Function parameter or member
'indio_dev' not described in 'stm32_adc_debugfs_reg_access'
drivers/iio/adc/stm32-adc.c:1420: warning: Function parameter or member
'reg' not described in 'stm32_adc_debugfs_reg_access'
drivers/iio/adc/stm32-adc.c:1420: warning: Function parameter or member
'writeval' not described in 'stm32_adc_debugfs_reg_access'
drivers/iio/adc/stm32-adc.c:1420: warning: Function parameter or member
'readval' not described in 'stm32_adc_debugfs_reg_access'

Signed-off-by: Fabrice Gasnier <fabrice.gasnier@st.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: adc: stm32-adc: fix a race when using several adcs with dma and irq

End of conversion may be handled by using IRQ or DMA. There may be a
race when two conversions complete at the same time on several ADCs.
EOC can be read as 'set' for several ADCs, with:
- an ADC configured to use IRQs. EOCIE bit is set. The handler is normally
called in this case.
- an ADC configured to use DMA. EOCIE bit isn't set. EOC triggers the DMA
request instead. It's then automatically cleared by DMA read. But the
handler gets called due to status bit is temporarily set (IRQ triggered
by the other ADC).
So both EOC status bit in CSR and EOCIE control bit must be checked
before invoking the interrupt handler (e.g. call ISR only for
IRQ-enabled ADCs).

Fixes: 2763ea0585c9 ("iio: adc: stm32: add optional dma support")

Signed-off-by: Fabrice Gasnier <fabrice.gasnier@st.com>
Cc: <Stable@vger.kernel.org>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: adc: stm32-adc: move registers definitions

Move STM32 ADC registers definitions to common header.
This is precursor patch to:
- iio: adc: stm32-adc: fix a race when using several adcs with dma and irq

It keeps registers definitions as a whole block, to ease readability and
allow simple access path to EOC bits (readl) in stm32-adc-core driver.

Fixes: 2763ea0585c9 ("iio: adc: stm32: add optional dma support")

Signed-off-by: Fabrice Gasnier <fabrice.gasnier@st.com>
Cc: <Stable@vger.kernel.org>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: Remove dev_err() usage after platform_get_irq()

We don't need dev_err() messages when platform_get_irq() fails now that
platform_get_irq() prints an error message itself when something goes
wrong. Let's remove these prints with a simple semantic patch.

// <smpl>
@@
expression ret;
struct platform_device *E;
@@

ret =
(
platform_get_irq(E, ...)
|
platform_get_irq_byname(E, ...)
);

if ( \( ret < 0 \| ret <= 0 \) )
{
(
-if (ret != -EPROBE_DEFER)
-{ ...
-dev_err(...);
-... }
|
...
-dev_err(...);
)
...
}
// </smpl>

While we're here, remove braces on if statements that only have one
statement (manually).

Cc: Jonathan Cameron <jic23@kernel.org>
Cc: Hartmut Knaack <knaack.h@gmx.de>
Cc: Lars-Peter Clausen <lars@metafoo.de>
Cc: Peter Meerwald-Stadler <pmeerw@pmeerw.net>
Cc: linux-iio@vger.kernel.org
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Stephen Boyd <swboyd@chromium.org>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: adc: stm32-adc: add analog switches supply control

On stm32h7 and stm32mp1, the ADC inputs are multiplexed with analog
switches which have reduced performances when their supply is below 2.7V
(vdda by default):
- 3.3V embedded booster can be used, to get full ADC performances
(increases power consumption).
- vdd supply can be selected if above 2.7V by setting ANASWVDD syscfg bit,
on STM32MP1 only.

Make this optional, since this is a trade-off between analog performance
and power consumption.

Signed-off-by: Fabrice Gasnier <fabrice.gasnier@st.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: adc: stm32-adc: add missing vdda-supply

Add missing vdda-supply, analog power supply, to STM32 ADC. When vdda is
an independent supply, it needs to be properly turned on or off to supply
the ADC.

Signed-off-by: Fabrice Gasnier <fabrice.gasnier@st.com>
Fixes: 1add69880240 ("iio: adc: Add support for STM32 ADC core").
Cc: <Stable@vger.kernel.org>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: adc: stm32-adc: add power management support

Add support for runtime PM & sleep. Move all regulator and clock management
to dedicated HW start/stop routines. Then rely on (runtime) PM OPS to
call them.

Signed-off-by: Fabrice Gasnier <fabrice.gasnier@st.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: adc: stm32-adc: add support for STM32MP1

Add support for STM32MP1 ADC. It's quite similar to STM32H7 ADC.
Introduce new compatible to handle variants of this hardware such as
vregready flag, trigger list, interrupts, clock rate.

Signed-off-by: Fabrice Gasnier <fabrice.gasnier@st.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: stm32: Adopt SPDX identifier

Add SPDX identifier in stm32's files in IIO directory

Signed-off-by: Benjamin Gaignard <benjamin.gaignard@st.com>
Acked-by: Fabrice Gasnier <fabrice.gasnier@st.com>
Acked-by: Philippe Ombredanne <pombredanne@nexb.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

iio: adc: stm32: add check on clock rate

Add check on STM32 ADC clock rate to report an explicit error.
This may avoid division by 0 later in stm32-adc driver.

Signed-off-by: Fabrice Gasnier <fabrice.gasnier@st.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: adc: stm32: fix common clock rate

ADC clock input is provided to internal prescaler (that decreases its
frequency). It's then used as reference clock for conversions.

- Fix common clock rate used then by stm32-adc sub-devices. Take common
prescaler into account. Currently, rate is used to set "boost" mode.
It may unnecessarily be set. This impacts power consumption.
- Fix ADC max clock rate on STM32H7 (fADC from datasheet). Currently,
prescaler may be set too low. This can result in ADC reference
clock used for conversion to exceed max allowed clock frequency.

Fixes: 95e339b6e85d ("iio: adc: stm32: add support for STM32H7")
Signed-off-by: Fabrice Gasnier <fabrice.gasnier@st.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: adc: stm32: make array stm32h7_adc_ckmodes_spec static

The array stm32h7_adc_ckmodes_spec does not need to be in global scope, so
make it static.

Cleans up sparse warning:
"symbol 'stm32h7_adc_ckmodes_spec' was not declared. Should it be static?"

Signed-off-by: Colin Ian King <colin.king@canonical.com>
Acked-by: Fabrice Gasnier <fabrice.gasnier@st.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

iio: adc: stm32: add support for STM32H7

Add support for STM32H7 Analog to Digital Converter. It has up
to 20 external channels, resolution ranges from 8 to 16bits.
Either bus or asynchronous adc clock may be used.

Add registers & bitfields definition. Also add new configuration
options to enter/exit powerdown and perform self-calibration.

Signed-off-by: Fabrice Gasnier <fabrice.gasnier@st.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

iio: adc: stm32: introduce compatible data cfg

Prepare support for stm32h7 adc variant by introducing compatible
configuration data.
Move STM32F4 specific stuff to compatible data structure:
- registers & bit fields
- input channels data
- start/stop procedures
- trigger definitions

Signed-off-by: Fabrice Gasnier <fabrice.gasnier@st.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

iio: adc: stm32: make core adc clock optional by default

Analog clock input is mandatory on stm32f4. But newer version of
ADC hardware block allow to select either bus clock or asynchronous
clock, for analog circuitry.

So, make it optional by default, but enforce clk presence on stm32f4.

Signed-off-by: Fabrice Gasnier <fabrice.gasnier@st.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

iio: adc: stm32: add optional dma support

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: Fabrice Gasnier <fabrice.gasnier@st.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

iio: adc: Add support for STM32 ADC core

Add core driver for STMicroelectronics STM32 ADC (Analog to Digital
Converter). STM32 ADC can be composed of up to 3 ADCs with shared
resources like clock prescaler, common interrupt line and analog
reference voltage.
This core driver basically manages shared resources.

Signed-off-by: Fabrice Gasnier <fabrice.gasnier@st.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>