Linux kernel ============ The Linux kernel is the core of any Linux operating system. It manages hardware, system resources, and provides the fundamental services for all other software. Quick Start ----------- * Report a bug: See Documentation/admin-guide/reporting-issues.rst * Get the latest kernel: https://kernel.org * Build the kernel: See Documentation/admin-guide/quickly-build-trimmed-linux.rst * Join the community: https://lore.kernel.org/ Essential Documentation ----------------------- All users should be familiar with: * Building requirements: Documentation/process/changes.rst * Code of Conduct: Documentation/process/code-of-conduct.rst * License: See COPYING Documentation can be built with make htmldocs or viewed online at: https://www.kernel.org/doc/html/latest/ Who Are You? ============ Find your role below: * New Kernel Developer - Getting started with kernel development * Academic Researcher - Studying kernel internals and architecture * Security Expert - Hardening and vulnerability analysis * Backport/Maintenance Engineer - Maintaining stable kernels * System Administrator - Configuring and troubleshooting * Maintainer - Leading subsystems and reviewing patches * Hardware Vendor - Writing drivers for new hardware * Distribution Maintainer - Packaging kernels for distros For Specific Users ================== New Kernel Developer -------------------- Welcome! Start your kernel development journey here: * Getting Started: Documentation/process/development-process.rst * Your First Patch: Documentation/process/submitting-patches.rst * Coding Style: Documentation/process/coding-style.rst * Build System: Documentation/kbuild/index.rst * Development Tools: Documentation/dev-tools/index.rst * Kernel Hacking Guide: Documentation/kernel-hacking/hacking.rst * Core APIs: Documentation/core-api/index.rst Academic Researcher ------------------- Explore the kernel's architecture and internals: * Researcher Guidelines: Documentation/process/researcher-guidelines.rst * Memory Management: Documentation/mm/index.rst * Scheduler: Documentation/scheduler/index.rst * Networking Stack: Documentation/networking/index.rst * Filesystems: Documentation/filesystems/index.rst * RCU (Read-Copy Update): Documentation/RCU/index.rst * Locking Primitives: Documentation/locking/index.rst * Power Management: Documentation/power/index.rst Security Expert --------------- Security documentation and hardening guides: * Security Documentation: Documentation/security/index.rst * LSM Development: Documentation/security/lsm-development.rst * Self Protection: Documentation/security/self-protection.rst * Reporting Vulnerabilities: Documentation/process/security-bugs.rst * CVE Procedures: Documentation/process/cve.rst * Embargoed Hardware Issues: Documentation/process/embargoed-hardware-issues.rst * Security Features: Documentation/userspace-api/seccomp_filter.rst Backport/Maintenance Engineer ----------------------------- Maintain and stabilize kernel versions: * Stable Kernel Rules: Documentation/process/stable-kernel-rules.rst * Backporting Guide: Documentation/process/backporting.rst * Applying Patches: Documentation/process/applying-patches.rst * Subsystem Profile: Documentation/maintainer/maintainer-entry-profile.rst * Git for Maintainers: Documentation/maintainer/configure-git.rst System Administrator -------------------- Configure, tune, and troubleshoot Linux systems: * Admin Guide: Documentation/admin-guide/index.rst * Kernel Parameters: Documentation/admin-guide/kernel-parameters.rst * Sysctl Tuning: Documentation/admin-guide/sysctl/index.rst * Tracing/Debugging: Documentation/trace/index.rst * Performance Security: Documentation/admin-guide/perf-security.rst * Hardware Monitoring: Documentation/hwmon/index.rst Maintainer ---------- Lead kernel subsystems and manage contributions: * Maintainer Handbook: Documentation/maintainer/index.rst * Pull Requests: Documentation/maintainer/pull-requests.rst * Managing Patches: Documentation/maintainer/modifying-patches.rst * Rebasing and Merging: Documentation/maintainer/rebasing-and-merging.rst * Development Process: Documentation/process/maintainer-handbooks.rst * Maintainer Entry Profile: Documentation/maintainer/maintainer-entry-profile.rst * Git Configuration: Documentation/maintainer/configure-git.rst Hardware Vendor --------------- Write drivers and support new hardware: * Driver API Guide: Documentation/driver-api/index.rst * Driver Model: Documentation/driver-api/driver-model/driver.rst * Device Drivers: Documentation/driver-api/infrastructure.rst * Bus Types: Documentation/driver-api/driver-model/bus.rst * Device Tree Bindings: Documentation/devicetree/bindings/ * Power Management: Documentation/driver-api/pm/index.rst * DMA API: Documentation/core-api/dma-api.rst Distribution Maintainer ----------------------- Package and distribute the kernel: * Stable Kernel Rules: Documentation/process/stable-kernel-rules.rst * ABI Documentation: Documentation/ABI/README * Kernel Configuration: Documentation/kbuild/kconfig.rst * Module Signing: Documentation/admin-guide/module-signing.rst * Kernel Parameters: Documentation/admin-guide/kernel-parameters.rst * Tainted Kernels: Documentation/admin-guide/tainted-kernels.rst Communication and Support ========================= * Mailing Lists: https://lore.kernel.org/ * IRC: #kernelnewbies on irc.oftc.net * Bugzilla: https://bugzilla.kernel.org/ * MAINTAINERS file: Lists subsystem maintainers and mailing lists * Email Clients: Documentation/process/email-clients.rst
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The S2MPG11 PMIC is a Power Management IC for mobile applications with
buck converters, various LDOs, power meters, and additional GPIO
interfaces. It typically complements an S2MPG10 PMIC in a main/sub
configuration as the sub-PMIC.
It has 12 buck, 1 buck-boost, and 15 LDO rails. Several of these can
either be controlled via software (register writes) or via external
signals, in particular by:
* input pins connected to a main processor's:
* GPIO pins
* other pins that are e.g. firmware- or power-domain-controlled
without explicit driver intervention
* a combination of input pins and register writes.
Control via input pins allows PMIC rails to be controlled by firmware,
e.g. during standby/suspend or as part of power domain handling where
otherwise that would not be possible. Additionally toggling a pin is
faster than register writes, and it also allows the PMIC to ensure that
any necessary timing requirements between rails are respected
automatically if multiple rails are to be enabled or disabled quasi
simultaneously.
This commit implements support for all these rails and control
combination.
Note1: For an externally controlled rail, the regulator_ops provide an
empty ::enable() and no ::disable() implementations, even though Linux
can not enable the rail and one might think ::enable could be NULL.
Without ops->enable(), the regulator core will assume enabling such a
rail failed, though, and in turn never add a reference to its parent
(supplier) rail. Once a different (Linux-controlled) sibling (consumer)
rail on that same parent rail gets disabled, the parent gets disabled
(cutting power to the externally controlled rail although it should
stay on), and the system will misbehave.
Note2: While external control via input pins appears to exist on other
versions of this PMIC, there is more flexibility in this version, in
particular there is a selection of input pins to choose from for each
rail (which must therefore be configured accordingly if in use),
whereas other versions don't have this flexibility.
Signed-off-by: André Draszik <andre.draszik@linaro.org>
Link: https://patch.msgid.link/20260122-s2mpg1x-regulators-v7-19-3b1f9831fffd@linaro.org
Signed-off-by: Mark Brown <broonie@kernel.org>
Rails in the S2MPG11 share a very similar set of properties with
S2MPG10 with slight differences. Update the existing macros to allow
reuse by the upcoming S2MPG11 driver.
Signed-off-by: André Draszik <andre.draszik@linaro.org>
Link: https://patch.msgid.link/20260122-s2mpg1x-regulators-v7-18-3b1f9831fffd@linaro.org
Signed-off-by: Mark Brown <broonie@kernel.org>
The upcoming S2MPG11 support needs a similar, but different version of
::set_voltage_time(). For S2MPG10, the downwards and upwards ramps for
a rail are at different offsets at the same bit positions, while for
S2MPG11 the ramps are at the same offset at different bit positions.
Refactor the existing version slightly to allow reuse.
Signed-off-by: André Draszik <andre.draszik@linaro.org>
Link: https://patch.msgid.link/20260122-s2mpg1x-regulators-v7-17-3b1f9831fffd@linaro.org
Signed-off-by: Mark Brown <broonie@kernel.org>
The S2MPG10 PMIC is a Power Management IC for mobile applications with
buck converters, various LDOs, power meters, RTC, clock outputs, and
additional GPIO interfaces.
It has 10 buck and 31 LDO rails. Several of these can either be
controlled via software (register writes) or via external signals, in
particular by:
* one out of several input pins connected to a main processor's:
* GPIO pins
* other pins that are e.g. firmware- or power-domain-controlled
without explicit driver intervention
* a combination of input pins and register writes.
Control via input pins allows PMIC rails to be controlled by firmware,
e.g. during standby/suspend, or as part of power domain handling where
otherwise that would not be possible. Additionally toggling a pin is
faster than register writes, and it also allows the PMIC to ensure that
any necessary timing requirements between rails are respected
automatically if multiple rails are to be enabled or disabled quasi
simultaneously.
This commit implements support for all these rails and control
combinations.
Additional data needs to be stored for each regulator, e.g. the input
pin for external control, or a rail-specific ramp-rate for when
enabling a buck-rail. Therefore, probe() is updated slightly to make
that possible.
Note1: For an externally controlled rail, the regulator_ops provide an
empty ::enable() and no ::disable() implementations, even though Linux
can not enable the rail and one might think ::enable could be NULL.
Without ops->enable(), the regulator core will assume enabling such a
rail failed, though, and in turn never add a reference to its parent
(supplier) rail. Once a different (Linux-controlled) sibling (consumer)
rail on that same parent rail gets disabled, the parent gets disabled
(cutting power to the externally controlled rail although it should
stay on), and the system will misbehave.
Note2: While external control via input pins appears to exist on other
versions of this PMIC, there is more flexibility in this version, in
particular there is a selection of input pins to choose from for each
rail (which must therefore be configured accordingly if in use),
whereas other versions don't have this flexibility.
Signed-off-by: André Draszik <andre.draszik@linaro.org>
Link: https://patch.msgid.link/20260122-s2mpg1x-regulators-v7-16-3b1f9831fffd@linaro.org
Signed-off-by: Mark Brown <broonie@kernel.org>
Refactor s2mps14_pmic_enable_ext_control() and s2mps11_of_parse_cb()
slightly as a preparation for adding S2MPG10 and S2MPG11 support, as
both of those PMICs also support control of rails via GPIOs.
This also includes the following to avoid further updates in follow-up
commits:
* On S2MPG10 and S2MPG11, external rail control can be via GPIO or via
non-GPIO signals, hence passing a GPIO is allowed to be optional.
This avoids inappropriate verbose driver messages.
* Prepare to allow use of standard DT property name 'enable-gpios' for
newer platforms instead of vendor-specific 'samsung,ext-control'.
Signed-off-by: André Draszik <andre.draszik@linaro.org>
Link: https://patch.msgid.link/20260122-s2mpg1x-regulators-v7-15-3b1f9831fffd@linaro.org
Signed-off-by: Mark Brown <broonie@kernel.org>
For the upcoming S2MPG10 and S2MPG11 support, we need to be able to
parse -supply properties in the PMIC's DT node.
This currently doesn't work, because the code here currently points the
regulator core at each individual regulator sub-node, and therefore the
regulator core is unable to find the -supply properties.
Update the code to simply let the regulator core handle all the parsing
by adding the ::of_match and ::regulators_node members to all existing
regulator descriptions, by adding ::of_parse_cb() to those
regulators which support the vendor-specific samsung,ext-control-gpios
to parse it (S2MPS14), and by dropping the explicit call to
of_regulator_match().
Configuring the PMIC to respect the external control GPIOs via
s2mps14_pmic_enable_ext_control() is left outside ::of_parse_cb()
because the regulator core ignores errors other than -EPROBE_DEFER from
that callback, while the code currently fails probe on register write
errors and I believe it should stay that way.
The driver can now avoid the devm_gpiod_unhinge() dance due to
simpler error handling of GPIO descriptor acquisition.
This change also has the advantage of reducing runtime memory
consumption by quite a bit as the driver doesn't need to allocate a
'struct of_regulator_match' and a 'struct gpio_desc *' for each
regulator for all PMICs as the regulator core does that. This saves
40+8 bytes on arm64 for each individual regulator on all supported
PMICs (even on non-S2MPS14 due to currently unnecessarily allocating
the extra memory unconditionally). With the upcoming S2MPG10 and
S2MPG11 support, this amounts to 1640+328 and 1120+224 bytes
respectively.
Signed-off-by: André Draszik <andre.draszik@linaro.org>
Link: https://patch.msgid.link/20260122-s2mpg1x-regulators-v7-14-3b1f9831fffd@linaro.org
Signed-off-by: Mark Brown <broonie@kernel.org>
For the lines being changed, checkpatch reports:
WARNING: Comparisons should place the constant on the right side of the test
Update the code accordingly.
Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Signed-off-by: André Draszik <andre.draszik@linaro.org>
Link: https://patch.msgid.link/20260122-s2mpg1x-regulators-v7-13-3b1f9831fffd@linaro.org
Signed-off-by: Mark Brown <broonie@kernel.org>
dev_err_probe() exists to simplify code and harmonise error messages,
there's no reason not to use it here.
While at it, harmonise some error messages to add regulator name and ID
like in other messages in this driver, and update messages to be more
similar to other child-drivers of this PMIC (e.g. RTC).
Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Signed-off-by: André Draszik <andre.draszik@linaro.org>
Link: https://patch.msgid.link/20260122-s2mpg1x-regulators-v7-12-3b1f9831fffd@linaro.org
Signed-off-by: Mark Brown <broonie@kernel.org>
The initialisations being removed are needless, as both variables are
being assigned values unconditionally further down. Additionally, doing
this eager init here might lead to preventing the compiler from issuing
a warning if a future code change actually forgets to assign a useful
value in some code path.
Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Signed-off-by: André Draszik <andre.draszik@linaro.org>
Link: https://patch.msgid.link/20260122-s2mpg1x-regulators-v7-11-3b1f9831fffd@linaro.org
Signed-off-by: Mark Brown <broonie@kernel.org>
REGULATOR_LINEAR_VRANGE is similar to REGULATOR_LINEAR_RANGE, but
allows a more natural declaration of a voltage range for a regulator,
in that it expects the minimum and maximum values as voltages rather
than as selectors.
Using voltages arguably makes this macro easier to use by drivers and
code using it can become easier to read compared to
REGULATOR_LINEAR_RANGE.
Signed-off-by: André Draszik <andre.draszik@linaro.org>
Link: https://patch.msgid.link/20260122-s2mpg1x-regulators-v7-10-3b1f9831fffd@linaro.org
Signed-off-by: Mark Brown <broonie@kernel.org>
The S2MPG11 PMIC is a Power Management IC for mobile applications with
buck converters, various LDOs, power meters, NTC thermistor inputs, and
additional GPIO interfaces. It typically complements an S2MPG10 PMIC in
a main/sub configuration as the sub-PMIC.
S2MPG11 has 12 buck, 1 buck-boost, and 15 LDO rails. Several of these
can either be controlled via software (register writes) or via external
signals, in particular by:
* one out of several input pins connected to a main processor's:
* GPIO pins
* other pins that are e.g. firmware- or power-domain-controlled
without explicit driver intervention
* a combination of input pins and register writes.
Control via input pins allows PMIC rails to be controlled by firmware,
e.g. during standby/suspend, or as part of power domain handling where
otherwise that would not be possible. Additionally toggling a pin is
faster than register writes, and it also allows the PMIC to ensure that
any necessary timing requirements between rails are respected
automatically if multiple rails are to be enabled or disabled quasi
simultaneously.
While external control via input pins appears to exist on other
versions of this PMIC, there is more flexibility in this version, in
particular there is a selection of input pins to choose from for each
rail (which must therefore be configured accordingly if in use),
whereas other versions don't have this flexibility.
Add documentation related to the regulator (buck & ldo) parts like
devicetree definitions, regulator naming patterns, and additional
properties.
Since S2MPG11 is typically used as the sub-PMIC together with an
S2MPG10 as the main-PMIC, the datasheet and the binding both suffix the
rails with an 's'.
Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Signed-off-by: André Draszik <andre.draszik@linaro.org>
Link: https://patch.msgid.link/20260122-s2mpg1x-regulators-v7-3-3b1f9831fffd@linaro.org
Signed-off-by: Mark Brown <broonie@kernel.org>
The S2MPG10 PMIC is a Power Management IC for mobile applications with
buck converters, various LDOs, power meters, RTC, clock outputs, and
additional GPIO interfaces.
It has 10 buck and 31 LDO rails. Several of these can either be
controlled via software (register writes) or via external signals, in
particular by:
* one out of several input pins connected to a main processor's:
* GPIO pins
* other pins that are e.g. firmware- or power-domain-controlled
without explicit driver intervention
* a combination of input pins and register writes.
Control via input pins allows PMIC rails to be controlled by firmware,
e.g. during standby/suspend, or as part of power domain handling where
otherwise that would not be possible. Additionally toggling a pin is
faster than register writes, and it also allows the PMIC to ensure that
any necessary timing requirements between rails are respected
automatically if multiple rails are to be enabled or disabled quasi
simultaneously.
While external control via input pins appears to exist on other
versions of this PMIC, there is more flexibility in this version, in
particular there is a selection of input pins to choose from for each
rail (which must therefore be configured accordingly if in use),
whereas other versions don't have this flexibility.
Add documentation related to the regulator (buck & ldo) parts like
devicetree definitions, regulator naming patterns, and additional
properties.
S2MPG10 is typically used as the main-PMIC together with an S2MPG11
PMIC in a main/sub configuration, hence the datasheet and the binding
both suffix the rails with an 'm'.
Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Signed-off-by: André Draszik <andre.draszik@linaro.org>
Link: https://patch.msgid.link/20260122-s2mpg1x-regulators-v7-2-3b1f9831fffd@linaro.org
Signed-off-by: Mark Brown <broonie@kernel.org>
Using lowercase for the buck and ldo nodenames is preferred, as
evidenced e.g. in [1].
Convert the example here to lowercase before we add any bindings
describing the s2mpg1x regulators that will enforce the spelling.
Link: https://lore.kernel.org/all/20250223-mysterious-infrared-civet-e5bcbf@krzk-bin/ [1]
Acked-by: Rob Herring (Arm) <robh@kernel.org>
Signed-off-by: André Draszik <andre.draszik@linaro.org>
Link: https://patch.msgid.link/20260122-s2mpg1x-regulators-v7-1-3b1f9831fffd@linaro.org
Signed-off-by: Mark Brown <broonie@kernel.org>
Add support for Samsung's S2MPG11 PMIC, which is a Power Management IC
for mobile applications with buck converters, various LDOs, power
meters, NTC thermistor inputs, and additional GPIO interfaces. It
typically complements an S2MPG10 PMIC in a main/sub configuration as
the sub-PMIC.
Like S2MPG10, communication is not via I2C, but via the Samsung ACPM
firmware.
While at it, we can also switch to asynchronous probe, which helps with
probe performance, as the drivers for s2mpg10 and s2mpg11 can probe in
parallel.
Note: The firmware uses the ACPM channel ID and the Speedy channel ID
to select the PMIC address. Since these are firmware properties, they
can not be retrieved from DT, but instead are deducted from the
compatible for now.
Signed-off-by: André Draszik <andre.draszik@linaro.org>
Link: https://patch.msgid.link/20260122-s2mpg1x-regulators-v7-9-3b1f9831fffd@linaro.org
Signed-off-by: Lee Jones <lee@kernel.org>
Bucks can reasonably be supplies for LDOs, but not the other way
around. Since rail registration is going to be ordered by 'enum
s2mpg10_regulators', it makes sense to specify bucks first, so that
during LDO registration it is more likely that the corresponding supply
is known already.
This can improve probe speed, as no unnecessary deferrals and retries
are required anymore.
Signed-off-by: André Draszik <andre.draszik@linaro.org>
Link: https://patch.msgid.link/20260122-s2mpg1x-regulators-v7-8-3b1f9831fffd@linaro.org
Signed-off-by: Lee Jones <lee@kernel.org>
The Samsung S2MPG11 PMIC is similar to the existing S2MPG10 PMIC
supported by this binding, but still differs enough from it to justify
a separate binding.
It is a Power Management IC for mobile applications with buck
converters, various LDOs, power meters, NTC thermistor inputs, and
additional GPIO interfaces and typically complements an S2MPG10 PMIC in
a main/sub configuration as the sub-PMIC.
Like S2MPG10, communication is via the Samsung ACPM firmware and it
therefore needs to be a child of the ACPM firmware node.
Add the PMIC, the regulators node, and the supply inputs of the
regulator rails, with the supply names matching the datasheet.
Note: S2MPG11 is typically used as the sub-PMIC together with an
S2MPG10 PMIC in a main/sub configuration, hence the datasheet and the
binding both suffix the supplies with an 's'.
Signed-off-by: André Draszik <andre.draszik@linaro.org>
Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Link: https://patch.msgid.link/20260122-s2mpg1x-regulators-v7-6-3b1f9831fffd@linaro.org
Signed-off-by: Lee Jones <lee@kernel.org>
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