This patch adds support for STMicroelectronics STM32 ADC (analog to
digital converter). It's originally based on Linux kernel v4.18-rcs
drivers/iio/adc/stm32-adc*. It's composed of:
- core driver (UCLASS_SIMPLE_BUS) manages common resources (clk, regu).
- child drivers (UCLASS_ADC) declare each ADC, channels and handle
  conversions.
This driver currently supports STM32H7 and STM32MP1 ADC.

Signed-off-by: Fabrice Gasnier <fabrice.gasnier@st.com>
Reviewed-by: Simon Glass <sjg@chromium.org>

device_get_supply_regulator() only needs to be called once.
But each time there's call to adc_vxx_value() for instance, it calls
adc_vxx_platdata_update() -> device_get_supply_regulator().

So, move device_get_supply_regulator() to pre_probe() routine.

This also allows vdd_supply/vss_supply to be provided directly from
uc_pdata, e.g dt-binding variant like stm32-adc provide its own
'vref-supply'.

Signed-off-by: Fabrice Gasnier <fabrice.gasnier@st.com>
Reviewed-by: Simon Glass <sjg@chromium.org>

The SARADC driver was merged after the following commit :
commit d35812368a59 ("regmap: change regmap_init_mem() to take ofnode instead udevice")
Thus breaking build, this patch fixes the regmap_init_mem accordingly.

Signed-off-by: Neil Armstrong <narmstrong@baylibre.com>

This patch adds the driver for the Amlogic Meson Successive Approximation
Register (SAR) A/D Converter based on the Linux IIO driver thanks to the
great work of Martin Blumenstingl.
The driver has been adapted to U-Boot and the ADC UClass.

This patch depends on the regmap "regmap: add regmap_update_bits() helper"
patch and has been tested using the newly introducted "adc" CLI command
in the "cmd: add ADC cli commands" patch.

Signed-off-by: Neil Armstrong <narmstrong@baylibre.com>

When U-Boot started using SPDX tags we were among the early adopters and
there weren't a lot of other examples to borrow from.  So we picked the
area of the file that usually had a full license text and replaced it
with an appropriate SPDX-License-Identifier: entry.  Since then, the
Linux Kernel has adopted SPDX tags and they place it as the very first
line in a file (except where shebangs are used, then it's second line)
and with slightly different comment styles than us.

In part due to community overlap, in part due to better tag visibility
and in part for other minor reasons, switch over to that style.

This commit changes all instances where we have a single declared
license in the tag as both the before and after are identical in tag
contents.  There's also a few places where I found we did not have a tag
and have introduced one.

Signed-off-by: Tom Rini <trini@konsulko.com>

We have a large number of places where while we historically referenced
gd in the code we no longer do, as well as cases where the code added
that line "just in case" during development and never dropped it.

Signed-off-by: Tom Rini <trini@konsulko.com>

U-Boot widely uses error() as a bit noisier variant of printf().

This macro causes name conflict with the following line in
include/linux/compiler-gcc.h:

  # define __compiletime_error(message) __attribute__((error(message)))

This prevents us from using __compiletime_error(), and makes it
difficult to fully sync BUILD_BUG macros with Linux.  (Notice
Linux's BUILD_BUG_ON_MSG is implemented by using compiletime_assert().)

Let's convert error() into now treewide-available pr_err().

Done with the help of Coccinelle, excluing tools/ directory.

The semantic patch I used is as follows:

// <smpl>
@@@@
-error
+pr_err
 (...)
// </smpl>

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
[trini: Re-run Coccinelle]
Signed-off-by: Tom Rini <trini@konsulko.com>

The ADC can support some channels signal-ended some bits Successive Approximation
Register (SAR) A/D Converter, like 6-channel and 10-bit. It converts the analog
input signal into some bits binary digital codes.

Signed-off-by: David Wu <david.wu@rock-chips.com>
Acked-by: Philipp Tomsich <philipp.tomsich@theobroma-systems.com>
Reviewed-by: Philipp Tomsich <philipp.tomsich@theobroma-systems.com>

Update the adc uclass to support a live device tree.

Signed-off-by: Simon Glass <sjg@chromium.org>

These support the flat device tree. We want to use the dev_read_..()
prefix for functions that support both flat tree and live tree. So rename
the existing functions to avoid confusion.

In the end we will have:

   1. dev_read_addr...()    - works on devices, supports flat/live tree
   2. devfdt_get_addr...()  - current functions, flat tree only
   3. of_get_address() etc. - new functions, live tree only

All drivers will be written to use 1. That function will in turn call
either 2 or 3 depending on whether the flat or live tree is in use.

Note this involves changing some dead code - the imx_lpi2c.c file.

Signed-off-by: Simon Glass <sjg@chromium.org>