soc: samsung: exynos-pmu: Add regmap support for SoCs that protect PMU regs

Some Exynos based SoCs like Tensor gs101 protect the PMU registers for
security hardening reasons so that they are only write accessible in el3
via an SMC call.

As most Exynos drivers that need to write PMU registers currently obtain a
regmap via syscon (phys, pinctrl, watchdog). Support for the above usecase
is implemented in this driver using a custom regmap similar to syscon to
handle the SMC call. Platforms that don't secure PMU registers, get a mmio
regmap like before. As regmaps abstract out the underlying register access
changes to the leaf drivers are minimal.

A new API exynos_get_pmu_regmap_by_phandle() is provided for leaf drivers
that currently use syscon_regmap_lookup_by_phandle(). This also handles
deferred probing.

Tested-by: Sam Protsenko <semen.protsenko@linaro.org>
Tested-by: Alexey Klimov <alexey.klimov@linaro.org>
Reviewed-by: Sam Protsenko <semen.protsenko@linaro.org>
Signed-off-by: Peter Griffin <peter.griffin@linaro.org>
Link: https://lore.kernel.org/r/20240220220613.797068-2-peter.griffin@linaro.org
Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>

pmdomain: samsung: Move Kconfig option to the pmdomain subsystem

The Kconfig option belongs closer to the corresponding implementation,
hence let's move it from the soc subsystem to the pmdomain subsystem.

Cc: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Cc: Alim Akhtar <alim.akhtar@samsung.com>
Cc: <linux-samsung-soc@vger.kernel.org>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>

soc: s3c: remove pm-debug hack

CONFIG_SAMSUNG_PM_DEBUG was only used on s3c24xx because of the
DEBUG_S3C24XX_UART dependency. Since s3c24xx is now gone, and nobody
ever noticed this option being missing from s3c64xx, it can be safely
removed as well.

Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>

ARM: s3c: remove all s3c24xx support

The platform was deprecated in commit 6a5e69c7ddea ("ARM: s3c: mark
as deprecated and schedule removal") and can be removed. This includes
all files that are exclusively for s3c24xx and not shared with s3c64xx,
as well as the glue logic in Kconfig and the maintainer file entries.

Cc: Arnaud Patard <arnaud.patard@rtp-net.org>
Cc: Ben Dooks <ben-linux@fluff.org>
Cc: Christer Weinigel <christer@weinigel.se>
Cc: Guillaume GOURAT <guillaume.gourat@nexvision.tv>
Cc: Heiko Stuebner <heiko@sntech.de>
Cc: Simtec Linux Team <linux@simtec.co.uk>
Cc: openmoko-kernel@lists.openmoko.org
Acked-by: Heiko Stuebner <heiko@sntech.de>
Acked-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>

soc: samsung: Fix typo in CONFIG_EXYNOS_USI description

The proper name is Exynos Auto V9, not V0. It was the typo slipped in
unnoticed, fix it.

Fixes: b603377e408f ("soc: samsung: Add USI driver")
Signed-off-by: Sam Protsenko <semen.protsenko@linaro.org>
Reviewed-by: Chanho Park <chanho61.park@samsung.com>
Link: https://lore.kernel.org/r/20220114144606.24358-1-semen.protsenko@linaro.org
Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@canonical.com>

soc: samsung: Add USI driver

USIv2 IP-core is found on modern ARM64 Exynos SoCs (like Exynos850) and
provides selectable serial protocol (one of: UART, SPI, I2C). USIv2
registers usually reside in the same register map as a particular
underlying protocol it implements, but have some particular offset. E.g.
on Exynos850 the USI_UART has 0x13820000 base address, where UART
registers have 0x00..0x40 offsets, and USI registers have 0xc0..0xdc
offsets. Desired protocol can be chosen via SW_CONF register from System
Register block of the same domain as USI.

Before starting to use a particular protocol, USIv2 must be configured
properly:
1. Select protocol to be used via System Register
2. Clear "reset" flag in USI_CON
3. Configure HWACG behavior (e.g. for UART Rx the HWACG must be
disabled, so that the IP clock is not gated automatically); this is
done using USI_OPTION register
4. Keep both USI clocks (PCLK and IPCLK) running during USI registers
modification

This driver implements the above behavior. Of course, USIv2 driver
should be probed before UART/I2C/SPI drivers. It can be achieved by
embedding UART/I2C/SPI nodes inside of the USI node (in Device Tree);
driver then walks underlying nodes and instantiates those. Driver also
handles USI configuration on PM resume, as register contents can be lost
during CPU suspend.

This driver is designed with different USI versions in mind. So it
should be relatively easy to add new USI revisions to it later.

Signed-off-by: Sam Protsenko <semen.protsenko@linaro.org>
Link: https://lore.kernel.org/r/20211204195757.8600-3-semen.protsenko@linaro.org
Tested-by: Chanho Park <chanho61.park@samsung.com>
Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@canonical.com>

soc: samsung: exynos-chipid: do not enforce built-in

After converting the Exynos ChipID and ASV driver to a module, allow to
actually choose it to be a module, while being a default built-in. The
side effect is that driver could be now entirely disabled even for
kernel with ARCH_EXYNOS, but this is not a critical issue because driver
is not necessary for the proper platform boot.

Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@canonical.com>
Reviewed-by: Sylwester Nawrocki <snawrocki@kernel.org>
Tested-by: Sylwester Nawrocki <snawrocki@kernel.org>
Reviewed-by: Alim Akhtar <alim.akhtar@samsung.com>
Tested-by: Alim Akhtar <alim.akhtar@samsung.com>
Link: https://lore.kernel.org/r/20210919093114.35987-4-krzysztof.kozlowski@canonical.com

soc: samsung: exynos-chipid: convert to a module

Exynos ChipID and ASV (Adaptive Supply Voltage) driver is not essential
to system boot and it can successfully be built and loaded as module.

This makes core kernel image smaller and reduces the memory footprint
when multi-platform kernel is booted on non-Exynos board. Usually it is
also distro-friendly.

Add multiple authors of the driver since its conversion from
mach-exynos, ordered alphabetically by first name.

Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@canonical.com>
Reviewed-by: Sylwester Nawrocki <snawrocki@kernel.org>
Tested-by: Sylwester Nawrocki <snawrocki@kernel.org>
Reviewed-by: Alim Akhtar <alim.akhtar@samsung.com>
Tested-by: Alim Akhtar <alim.akhtar@samsung.com>
Link: https://lore.kernel.org/r/20210919093114.35987-3-krzysztof.kozlowski@canonical.com

soc: samsung: exynos-pmu: Fix compilation when nothing selects CONFIG_MFD_CORE

Commit 93618e344a5e ("soc: samsung: exynos-pmu: instantiate clkout
driver as MFD") adds a "devm_mfd_add_devices" call in the exynos-pmu
driver which depends on CONFIG_MFD_CORE. If no driver selects that
config, the build will fail if CONFIG_EXYNOS_PMU is enabled with the
following error:

drivers/soc/samsung/exynos-pmu.c:137: undefined reference to `devm_mfd_add_devices'

Fix this by making CONFIG_EXYNOS_PMU select CONFIG_MFD_CORE.

Fixes: 93618e344a5e ("soc: samsung: exynos-pmu: instantiate clkout driver as MFD")
Cc: <stable@vger.kernel.org>
Signed-off-by: David Virag <virag.david003@gmail.com>
Link: https://lore.kernel.org/r/20210909222812.108614-1-virag.david003@gmail.com
Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@canonical.com>

soc: samsung: exynos-chipid: convert to driver and merge exynos-asv

The Exynos Chip ID driver on Exynos SoCs has so far only informational
purpose - to expose the SoC device in sysfs. No other drivers depend on
it so there is really no benefit of initializing it early.

The code would be the most flexible if converted to a regular driver.
However there is already another driver - Exynos ASV (Adaptive Supply
Voltage) - which binds to the device node of Chip ID.

The solution is to convert the Exynos Chip ID to a built in driver and
merge the Exynos ASV into it.

This has several benefits:
1. Although the Exynos ASV driver binds to a device node present in all
Exynos DTS (generic compatible), it fails to probe except on the
supported ones (only Exynos5422). This means that the regular boot
process has a planned/normal device probe failure.

Merging the ASV into Chip ID will remove this probe failure because
the final driver will always bind, just with disabled ASV features.

2. Allows to use dev_info() as the SoC bus is present (since
core_initcall).

3. Could speed things up because of execution of Chip ID code in a SMP
environment (after bringing up secondary CPUs, unlike early_initcall),
This reduces the amount of work to be done early, when the kernel has
to bring up critical devices.

5. Makes the Chip ID code defer-probe friendly,

Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>
Link: https://lore.kernel.org/r/20201207190517.262051-5-krzk@kernel.org
Reviewed-by: Pankaj Dubey <pankaj.dubey@samsung.com>

ARM: samsung: move pm check code to drivers/soc

This is the only part of plat-samsung that is really
shared between the s3c and s5p ports. Moving it to
drivers/soc/ lets us make them completely independent.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Link: https://lore.kernel.org/r/20200806182059.2431-16-krzk@kernel.org
Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>

soc: samsung: exynos-regulator-coupler: Add simple voltage coupler for Exynos5800

Add a simple custom voltage regulator coupler for Exynos5800 SoCs, which
require coupling between "vdd_arm" and "vdd_int" regulators. This coupler
ensures that the voltage values don't go below the bootloader-selected
operation point during the boot process until the clients set their
constraints. It is achieved by assuming minimal voltage value equal to
the current value if no constraints are set. This also ensures proper
voltage balancing if any of the client driver is missing.

The balancing code comes from the regulator/core.c with the additional
logic for handling regulators without client constraints applied added.

Link: https://lore.kernel.org/r/20200721180900.13844-5-krzk@kernel.org
Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
Reviewed-by: Dmitry Osipenko <digetx@gmail.com>
Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>

soc: samsung: Rename Samsung and Exynos to lowercase

Fix up inconsistent usage of upper and lowercase letters in "Samsung"
and "Exynos" names.

"SAMSUNG" and "EXYNOS" are not abbreviations but regular trademarked
names. Therefore they should be written with lowercase letters starting
with capital letter.

The lowercase "Exynos" name is promoted by its manufacturer Samsung
Electronics Co., Ltd., in advertisement materials and on website.

Although advertisement materials usually use uppercase "SAMSUNG", the
lowercase version is used in all legal aspects (e.g. on Wikipedia and in
privacy/legal statements on
https://www.samsung.com/semiconductor/privacy-global/).

Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>

soc: samsung: Add Exynos Adaptive Supply Voltage driver

The Adaptive Supply Voltage (ASV) driver adjusts CPU cluster operating
points depending on exact revision of an SoC retrieved from the CHIPID
block or the OTP memory. This allows for some power saving as for some
CPU clock frequencies we can lower CPU cluster's supply voltage comparing
to safe values common to all the SoC revisions.

This patch adds support for Exynos5422/5800 SoC, it is partially based
on code from https://github.com/hardkernel/linux repository,
branch odroidxu4-4.14.y, files: arch/arm/mach-exynos/exynos5422-asv.[ch].

Tested on Odroid XU3, XU4, XU3 Lite.

Signed-off-by: Sylwester Nawrocki <s.nawrocki@samsung.com>
Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>

soc: samsung: chipid: Select missing dependency for EXYNOS_CHIPID

The chipid driver uses the MFD syscon API but it was not covered
properly in Kconfig.

Signed-off-by: Sylwester Nawrocki <s.nawrocki@samsung.com>
Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>

soc: samsung: Add exynos chipid driver support

Exynos SoCs have Chipid, for identification of product IDs and SoC
revisions. This patch intends to provide initialization code for all
these functionalities, at the same time it provides some sysfs entries
for accessing these information to user-space.

This driver uses existing binding for exynos-chipid.

Changes by Bartlomiej:
- fixed return values on errors
- removed bogus kfree_const()
- added missing Exynos4210 EVT0 id
- converted code to use EXYNOS_MASK define
- fixed np use after of_node_put()
- fixed too early use of dev_info()
- made driver fail for unknown SoC-s
- added SPDX tag
- updated Copyrights

Signed-off-by: Pankaj Dubey <pankaj.dubey@samsung.com>
[m.szyprowski: for suggestion and code snippet of product_id_to_soc_id]
Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
Signed-off-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
[s.nawrocki: updated copyright date, removed uneeded headers inclusion]
Signed-off-by: Sylwester Nawrocki <s.nawrocki@samsung.com>
Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>

soc: samsung: Add SPDX license identifiers

Replace GPL license statements with SPDX GPL-2.0 license identifiers.

Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>

soc: samsung: Do not build ARMv7 PMU drivers on ARMv8

The Exynos Power Management Unit (PMU) drivers contain quite large
static arrays of register values necessary for given Exynos SoC to enter
low power mode. All this data is useless for ARMv8 SoC like
Exynos5433, because the image will not be shared between ARMv7 and
ARMv8.

Add additional Kconfig symbol for selecting the SoC-specific driver
addons thus skipping the useless data in the final image (this is
similar approach to chosen for Exynos clock controller drivers):
- exynos-pmu driver will be compiled on both architectures ARMv7
and ARMv8,
- additional driver_data for ARMv7 SoCs will not be built on ARMv8
and a macro will return NULL for them in of_device_id - this should
be safe as these compatibles cannot match on ARMv7 and driver
anyway handles NULL driver_data,
- on ARMv8 compile only exynos-pmu driver which exposes the
syscon-regmap for PMU address space.

Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>
Reviewed-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Reviewed-by: Alim Akhtar <alim.akhtar@samsung.com>

soc: samsung: pm_domains: Enable COMPILE_TEST for build coverage

Introduce a platform selectable symbol EXYNOS_PM_DOMAINS which can be
also toggled on by COMPILE_TEST for some build coverage.

Signed-off-by: Krzysztof Kozlowski <k.kozlowski@samsung.com>

drivers: soc: samsung: Enable COMPILE_TEST

Get some build coverage of Exynos PMU driver. It depends on
asm/cputype.h so its compilation is limited to ARM architectures.

Signed-off-by: Krzysztof Kozlowski <k.kozlowski@samsung.com>
Reviewed-by: Javier Martinez Canillas <javier@osg.samsung.com>

drivers: soc: Add support for Exynos PMU driver

This patch moves Exynos PMU driver implementation from "arm/mach-exynos"
to "drivers/soc/samsung". This driver is mainly used for setting misc
bits of register from PMU IP of Exynos SoC which will be required to
configure before Suspend/Resume. Currently all these settings are done
in "arch/arm/mach-exynos/pmu.c" but moving ahead for ARM64 based SoC
support, there is a need of this PMU driver in driver/* folder.

This driver uses existing DT binding information and there should
be no functionality change in the supported platforms.

Signed-off-by: Amit Daniel Kachhap <amitdanielk@gmail.com>
[tested on Peach-Pi (Exynos5880)]
Signed-off-by: Pankaj Dubey <pankaj.dubey@samsung.com>
Reviewed-by: Krzysztof Kozlowski <k.kozlowski@samsung.com>
[for testing on Trats2 (Exynos4412) and Odroid XU3 (Exynos5422)]
Tested-by: Krzysztof Kozlowski <k.kozlowski@samsung.com>
[k.kozlowski: Rebased, add necessary infrastructure for building and
selecting drivers/soc because original patchset was on top of movement
SROMc to drivers/soc]
Signed-off-by: Krzysztof Kozlowski <k.kozlowski@samsung.com>