linux-stable.git/include/linux/firmware/samsung, branch linux-rolling-stable Linux kernel stable tree firmware: samsung: acpm: remove compile-testing stubs 2026-07-24T14:19:24+00:00 Arnd Bergmann arnd@arndb.de 2026-05-29T13:43:31+00:00 f0115af6746eaee0232cefb6f38048a14c06cffb [ Upstream commit 7b661285aa7507eab79efff0a418445157db4141 ] Sashiko reported an inconsistent use of NULL vs ERR_PTR() returns in the stub helpers in xynos-acpm-protocol.h. Since this only happens on dead code for COMPILE_TEST=y, this is not really a bug though. Having stub functions that return NULL is a common way to define optional interfaces, where callers still work when the feature is disabled, though this clearly does not work for acpm because some callers have a NULL pointer dereference when compile testing. Since CONFIG_EXYNOS_ACPM_PROTOCOL already supports compile-testing itself, and all (both) drivers using it clearly require the support, so this just simplifies the option space without losing any build coverage. Remove the stub functions entirely and adjust the one Kconfig dependency to require EXYNOS_ACPM_PROTOCOL unconditionally. Fixes: 6837c006d4e7 ("firmware: exynos-acpm: add empty method to allow compile test") Closes: https://sashiko.dev/#/patchset/20260420-acpm-tmu-v3-0-3dc8e93f0b26%40linaro.org Link: https://lore.kernel.org/all/a7994860-24a3-4f87-84bf-109ed653dda4@linaro.org/ Reviewed-by: Tudor Ambarus <tudor.ambarus@linaro.org> Signed-off-by: Arnd Bergmann <arnd@arndb.de> Link: https://patch.msgid.link/20260529134454.2147446-1-arnd@kernel.org [krzk: Rebase on difference in devm_acpm_get_by_node()] Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit 7b661285aa7507eab79efff0a418445157db4141 ]

Sashiko reported an inconsistent use of NULL vs ERR_PTR()
returns in the stub helpers in xynos-acpm-protocol.h.

Since this only happens on dead code for COMPILE_TEST=y, this is not
really a bug though.  Having stub functions that return NULL is a common
way to define optional interfaces, where callers still work when the
feature is disabled, though this clearly does not work for acpm because
some callers have a NULL pointer dereference when compile testing.

Since CONFIG_EXYNOS_ACPM_PROTOCOL already supports compile-testing itself,
and all (both) drivers using it clearly require the support, so this
just simplifies the option space without losing any build coverage.

Remove the stub functions entirely and adjust the one Kconfig
dependency to require EXYNOS_ACPM_PROTOCOL unconditionally.

Fixes: 6837c006d4e7 ("firmware: exynos-acpm: add empty method to allow compile test")
Closes: https://sashiko.dev/#/patchset/20260420-acpm-tmu-v3-0-3dc8e93f0b26%40linaro.org
Link: https://lore.kernel.org/all/a7994860-24a3-4f87-84bf-109ed653dda4@linaro.org/
Reviewed-by: Tudor Ambarus <tudor.ambarus@linaro.org>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Link: https://patch.msgid.link/20260529134454.2147446-1-arnd@kernel.org
[krzk: Rebase on difference in devm_acpm_get_by_node()]
Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
firmware: samsung: acpm: Add devm_acpm_get_by_phandle helper 2026-07-24T14:19:24+00:00 Tudor Ambarus tudor.ambarus@linaro.org 2026-05-15T09:32:30+00:00 75c70913d30c3b3c395a4efa0d8c0e9c90553fa7 [ Upstream commit fc13a4b9b9c8cb0b8e5ba54b21712d00f810496c ] Introduce devm_acpm_get_by_phandle() to standardize how consumer drivers acquire a handle to the ACPM IPC interface. Enforce the use of the "samsung,acpm-ipc" property name across the SoC and simplify the boilerplate code in client drivers. The first consumer of this helper is the Exynos ACPM Thermal Management Unit (TMU) driver. The TMU utilizes a hybrid management approach: direct register access from the Application Processor (AP) is restricted to the interrupt pending (INTPEND) registers for event identification. High-level functional tasks, such as sensor initialization, threshold programming, and temperature reads, are delegated to the ACPM firmware via this IPC interface. Signed-off-by: Tudor Ambarus <tudor.ambarus@linaro.org> Reviewed-by: Peter Griffin <peter.griffin@linaro.org> Link: https://patch.msgid.link/20260515-acpm-tmu-helpers-v2-6-8ca011d5a965@linaro.org Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org> Stable-dep-of: 7b661285aa75 ("firmware: samsung: acpm: remove compile-testing stubs") Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit fc13a4b9b9c8cb0b8e5ba54b21712d00f810496c ]

Introduce devm_acpm_get_by_phandle() to standardize how consumer
drivers acquire a handle to the ACPM IPC interface. Enforce the
use of the "samsung,acpm-ipc" property name across the SoC and
simplify the boilerplate code in client drivers.

The first consumer of this helper is the Exynos ACPM Thermal Management
Unit (TMU) driver. The TMU utilizes a hybrid management approach: direct
register access from the Application Processor (AP) is restricted to the
interrupt pending (INTPEND) registers for event identification.
High-level functional tasks, such as sensor initialization, threshold
programming, and temperature reads, are delegated to the ACPM firmware
via this IPC interface.

Signed-off-by: Tudor Ambarus <tudor.ambarus@linaro.org>
Reviewed-by: Peter Griffin <peter.griffin@linaro.org>
Link: https://patch.msgid.link/20260515-acpm-tmu-helpers-v2-6-8ca011d5a965@linaro.org
Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>
Stable-dep-of: 7b661285aa75 ("firmware: samsung: acpm: remove compile-testing stubs")
Signed-off-by: Sasha Levin <sashal@kernel.org>
firmware: exynos-acpm: Drop fake 'const' on handle pointer 2026-02-28T14:47:03+00:00 Krzysztof Kozlowski krzysztof.kozlowski@oss.qualcomm.com 2026-02-24T10:42:04+00:00 a2be37eedb52ea26938fa4cc9de1ff84963c57ad All the functions operating on the 'handle' pointer are claiming it is a pointer to const thus they should not modify the handle. In fact that's a false statement, because first thing these functions do is drop the cast to const with container_of: struct acpm_info *acpm = handle_to_acpm_info(handle); And with such cast the handle is easily writable with simple: acpm->handle.ops.pmic_ops.read_reg = NULL; The code is not correct logically, either, because functions like acpm_get_by_node() and acpm_handle_put() are meant to modify the handle reference counting, thus they must modify the handle. Modification here happens anyway, even if the reference counting is stored in the container which the handle is part of. The code does not have actual visible bug, but incorrect 'const' annotations could lead to incorrect compiler decisions. Fixes: a88927b534ba ("firmware: add Exynos ACPM protocol driver") Cc: stable@vger.kernel.org Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@oss.qualcomm.com> Link: https://patch.msgid.link/20260224104203.42950-2-krzysztof.kozlowski@oss.qualcomm.com Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org> 
All the functions operating on the 'handle' pointer are claiming it is a
pointer to const thus they should not modify the handle.  In fact that's
a false statement, because first thing these functions do is drop the
cast to const with container_of:

  struct acpm_info *acpm = handle_to_acpm_info(handle);

And with such cast the handle is easily writable with simple:

  acpm->handle.ops.pmic_ops.read_reg = NULL;

The code is not correct logically, either, because functions like
acpm_get_by_node() and acpm_handle_put() are meant to modify the handle
reference counting, thus they must modify the handle.  Modification here
happens anyway, even if the reference counting is stored in the
container which the handle is part of.

The code does not have actual visible bug, but incorrect 'const'
annotations could lead to incorrect compiler decisions.

Fixes: a88927b534ba ("firmware: add Exynos ACPM protocol driver")
Cc: stable@vger.kernel.org
Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@oss.qualcomm.com>
Link: https://patch.msgid.link/20260224104203.42950-2-krzysztof.kozlowski@oss.qualcomm.com
Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>
firmware: exynos-acpm: add empty method to allow compile test 2025-10-22T05:49:38+00:00 Tudor Ambarus tudor.ambarus@linaro.org 2025-10-21T15:24:47+00:00 6837c006d4e72d6add451411bcf407e0dea4ad25 Provide empty method for devm_acpm_get_by_node() if we aren't building in the CONFIG_EXYNOS_ACPM_PROTOCOL. This allows to test-build the CONFIG_EXYNOS_ACPM_CLK code. Reported-by: kernel test robot <lkp@intel.com> Closes: https://lore.kernel.org/oe-kbuild-all/202510211905.RgfWkgss-lkp@intel.com/ Fixes: 40498a742053 ("clk: samsung: add Exynos ACPM clock driver") Signed-off-by: Tudor Ambarus <tudor.ambarus@linaro.org> Link: https://patch.msgid.link/20251021-fix-acpm-clk-build-test-v1-1-236a3d6db7f5@linaro.org Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org> 
Provide empty method for devm_acpm_get_by_node() if we aren't
building in the CONFIG_EXYNOS_ACPM_PROTOCOL. This allows to
test-build the CONFIG_EXYNOS_ACPM_CLK code.

Reported-by: kernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/oe-kbuild-all/202510211905.RgfWkgss-lkp@intel.com/
Fixes: 40498a742053 ("clk: samsung: add Exynos ACPM clock driver")
Signed-off-by: Tudor Ambarus <tudor.ambarus@linaro.org>
Link: https://patch.msgid.link/20251021-fix-acpm-clk-build-test-v1-1-236a3d6db7f5@linaro.org
Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
firmware: exynos-acpm: add DVFS protocol 2025-10-20T06:49:44+00:00 Tudor Ambarus tudor.ambarus@linaro.org 2025-10-10T12:46:32+00:00 84a222d1b369ba83f8947948670f775367e653f1 Add ACPM DVFS protocol handler. It constructs DVFS messages that the APM firmware can understand. Signed-off-by: Tudor Ambarus <tudor.ambarus@linaro.org> Reviewed-by: Peter Griffin <peter.griffin@linaro.org> Tested-by: Peter Griffin <peter.griffin@linaro.org> # on gs101-oriole Link: https://patch.msgid.link/20251010-acpm-clk-v6-2-321ee8826fd4@linaro.org Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org> 
Add ACPM DVFS protocol handler. It constructs DVFS messages that
the APM firmware can understand.

Signed-off-by: Tudor Ambarus <tudor.ambarus@linaro.org>
Reviewed-by: Peter Griffin <peter.griffin@linaro.org>
Tested-by: Peter Griffin <peter.griffin@linaro.org> # on gs101-oriole
Link: https://patch.msgid.link/20251010-acpm-clk-v6-2-321ee8826fd4@linaro.org
Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
firmware: exynos-acpm: introduce devm_acpm_get_by_node() 2025-04-22T07:50:06+00:00 André Draszik andre.draszik@linaro.org 2025-03-27T12:54:28+00:00 a8dc26a0ec43fd416ca781a8030807e65f71cfc5 To allow ACPM clients to simply be children of the ACPM node in DT, they need to be able to get the ACPM handle based on that ACPM node directly. Add an API to allow them to do so, devm_acpm_get_by_node(). At the same time, the previous approach of acquiring the ACPM handle via a DT phandle is now obsolete and we can remove devm_acpm_get_by_phandle(), which was there to facilitate that. There are no existing or anticipated upcoming users of that API, because all clients should be children of the ACPM node going forward. Note that no DTs have been merged that use the old approach, so doing this API change in this driver now will not affect any existing DTs or client drivers. Signed-off-by: André Draszik <andre.draszik@linaro.org> Link: https://lore.kernel.org/r/20250327-acpm-children-v1-2-0afe15ee2ff7@linaro.org Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org> 
To allow ACPM clients to simply be children of the ACPM node in DT,
they need to be able to get the ACPM handle based on that ACPM node
directly.

Add an API to allow them to do so, devm_acpm_get_by_node().

At the same time, the previous approach of acquiring the ACPM handle
via a DT phandle is now obsolete and we can remove
devm_acpm_get_by_phandle(), which was there to facilitate that. There
are no existing or anticipated upcoming users of that API, because all
clients should be children of the ACPM node going forward.

Note that no DTs have been merged that use the old approach, so doing
this API change in this driver now will not affect any existing DTs or
client drivers.

Signed-off-by: André Draszik <andre.draszik@linaro.org>
Link: https://lore.kernel.org/r/20250327-acpm-children-v1-2-0afe15ee2ff7@linaro.org
Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
firmware: add Exynos ACPM protocol driver 2025-02-16T10:45:51+00:00 Tudor Ambarus tudor.ambarus@linaro.org 2025-02-13T13:05:15+00:00 a88927b534ba18019b0440cf3d7f068407b5250c Alive Clock and Power Manager (ACPM) Message Protocol is defined for the purpose of communication between the ACPM firmware and masters (AP, AOC, ...). ACPM firmware operates on the Active Power Management (APM) module that handles overall power activities. ACPM and masters regard each other as independent hardware component and communicate with each other using mailbox messages and shared memory. This protocol driver provides the interface for all the client drivers making use of the features offered by the APM. Add ACPM protocol support. Signed-off-by: Tudor Ambarus <tudor.ambarus@linaro.org> Link: https://lore.kernel.org/r/20250213-gs101-acpm-v9-2-8b0281b93c8b@linaro.org Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org> 
Alive Clock and Power Manager (ACPM) Message Protocol is defined for
the purpose of communication between the ACPM firmware and masters
(AP, AOC, ...). ACPM firmware operates on the Active Power Management
(APM) module that handles overall power activities.

ACPM and masters regard each other as independent hardware component and
communicate with each other using mailbox messages and shared memory.

This protocol driver provides the interface for all the client drivers
making use of the features offered by the APM. Add ACPM protocol support.

Signed-off-by: Tudor Ambarus <tudor.ambarus@linaro.org>
Link: https://lore.kernel.org/r/20250213-gs101-acpm-v9-2-8b0281b93c8b@linaro.org
Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>