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* Re: [PATCH 1/3] arm64: dts: imx8mn-vhip4-evalboard-v1: Correct interrupt flags
From: Marek Vasut @ 2026-04-06 14:49 UTC (permalink / raw)
  To: Krzysztof Kozlowski, Rob Herring, Krzysztof Kozlowski,
	Conor Dooley, Frank Li, Sascha Hauer, Pengutronix Kernel Team,
	Fabio Estevam, Peng Fan, Fedor Ross, Shawn Guo, Shengjiu Wang,
	Viorel Suman, devicetree, imx, linux-arm-kernel, linux-kernel
In-Reply-To: <20260406063810.25531-4-krzysztof.kozlowski@oss.qualcomm.com>

On 4/6/26 8:38 AM, Krzysztof Kozlowski wrote:
> GPIO_ACTIVE_x flags are not correct in the context of interrupt flags.
> These are simple defines so they could be used in DTS but they will not
> have the same meaning:
> 1. GPIO_ACTIVE_HIGH = 0 => IRQ_TYPE_NONE
> 2. GPIO_ACTIVE_LOW  = 1 => IRQ_TYPE_EDGE_RISING
> 
> Correct the interrupt flags, assuming the author of the code wanted the
> same logical behavior behind the name "ACTIVE_xxx", this is:
> ACTIVE_LOW  => IRQ_TYPE_LEVEL_LOW
> 
> Fixes: 5eb7405db99b ("arm64: dts: imx8mn: Add ifm VHIP4 EvalBoard v1 and v2")
> Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@oss.qualcomm.com>
Reviewed-by: Marek Vasut <marex@nabladev.com>

^ permalink raw reply

* Re: [PATCH net-next v2 0/5] dpll: zl3073x: add ref-sync pair support
From: Jakub Kicinski @ 2026-04-06 15:30 UTC (permalink / raw)
  To: Ivan Vecera
  Cc: netdev, Arkadiusz Kubalewski, Jiri Pirko, Michal Schmidt,
	Petr Oros, Prathosh Satish, Simon Horman, Vadim Fedorenko,
	linux-kernel, Conor Dooley, Krzysztof Kozlowski, Rob Herring,
	devicetree, Pasi Vaananen
In-Reply-To: <20260328080624.593916-1-ivecera@redhat.com>

On Sat, 28 Mar 2026 09:06:19 +0100 Ivan Vecera wrote:
> This series adds Reference-Sync pair support to the ZL3073x DPLL driver.
> A Ref-Sync pair consists of a clock reference and a low-frequency sync
> signal (e.g. 1 PPS) where the DPLL locks to the clock reference but
> phase-aligns to the sync reference.

Hi Ivan, FWIW we're waiting for the DT review here.
I suspect some of the DT maintainers are AFK for Easter.

^ permalink raw reply

* Re: [PATCH v7 00/15] arm64: dts: qcom: sdm845-lg: Improve hardware support in devicetree
From: Paul Sajna @ 2026-04-06 15:30 UTC (permalink / raw)
  To: Bjorn Andersson, Konrad Dybcio, Rob Herring, Krzysztof Kozlowski,
	Conor Dooley, David Heidelberg
  Cc: linux-arm-msm, devicetree, linux-kernel, phone-devel,
	~postmarketos/upstreaming, Amir Dahan, Christopher Brown,
	Konrad Dybcio, Dmitry Baryshkov, Pavel Machek
In-Reply-To: <177541802142.2061229.9094394728986735362.b4-ty@kernel.org>

April 5, 2026 at 7:40 PM, "Bjorn Andersson" <andersson@kernel.org mailto:andersson@kernel.org?to=%22Bjorn%20Andersson%22%20%3Candersson%40kernel.org%3E > wrote:

> Applied, thanks!
> 
> [01/15] arm64: dts: qcom: sdm845-lg-common: Sort nodes and properties
>  commit: 6a9e8df732014c1c758bd3cd6254b5b4cb273c7f
> [02/15] arm64: dts: qcom: sdm845-lg-judyln: Add firmware nodes, change path
>  commit: b9afe8581c0e14b7b56e2314dc7f9597bf23ef67
> [03/15] arm64: dts: qcom: sdm845-lg-judyp: Define firmware paths for judyp
>  commit: 8f4c53ae286bd6a113245ad53ce957e623374cf0
> [04/15] arm64: dts: qcom: sdm845-lg-common: Enable venus
>  commit: e9f611de7ab51540c0cf246df6b7d4d99f4cec64
> [05/15] arm64: dts: qcom: sdm845-lg-common: Enable qups and their dma controllers
>  commit: 4ec3045c969a326c458c53ca65bde5749e575d52
> [06/15] arm64: dts: qcom: sdm845-lg: Add uarts and Bluetooth
>  commit: e746ed5af3084e9534135679c55e69eced0c657f
> [07/15] arm64: dts: qcom: sdm845-lg-judyln: Add battery and charger
>  commit: 995c258982429db93db103fc26fcb3a0acd6a5ee
> [08/15] arm64: dts: qcom: sdm845-lg-common: Add LEDs
>  commit: b49722c8a18cdd11f49357f3b8be23549f76a506
> [09/15] arm64: dts: qcom: sdm845-lg-judyln: Add lab/ibb
>  commit: 2e7cdd400b6a4e67c27fc3e839342824b51d01ff
> [10/15] arm64: dts: qcom: sdm845-lg-judyln: Add display panel
>  commit: c6c66aa3ef33dc3076c6dac64003b29bd9515b58
> [11/15] arm64: dts: qcom: sdm845-lg: Add wifi nodes
>  commit: eb8fa32085261a07d763e9d616b3c206d0be82ff
> [12/15] arm64: dts: qcom: sdm845-lg-common: Add chassis-type
>  commit: a5a5ad9848980e1019ca841fe057afb83debecfa
> 
> Best regards,
> -- 
> Bjorn Andersson <andersson@kernel.org>
>

Please apply 13-15. 15 is the only change in v8, so what you've pulled here from v7 is fine.

^ permalink raw reply

* Re: (subset) [PATCH v5 0/2] rtc: max77686: convert to i2c_new_ancillary_device
From: Mark Brown @ 2026-04-06 13:09 UTC (permalink / raw)
  To: Linus Walleij, Rob Herring, Krzysztof Kozlowski, Conor Dooley,
	Liam Girdwood, Svyatoslav Ryhel
  Cc: linux-gpio, devicetree, linux-kernel
In-Reply-To: <20260406075114.25672-1-clamor95@gmail.com>

On Mon, 06 Apr 2026 10:51:12 +0300, Svyatoslav Ryhel wrote:
> rtc: max77686: convert to i2c_new_ancillary_device
> 
> Convert RTC I2C device creation from devm_i2c_new_dummy_device() to
> i2c_new_ancillary_device() to enable the use of a device tree-specified
> RTC address instead of a hardcoded value. If the device tree does not
> provide an address, use hardcoded values as a fallback.
> 
> [...]

Applied to

   https://git.kernel.org/pub/scm/linux/kernel/git/broonie/regulator.git for-7.1

Thanks!

[1/2] regulator: dt-bindings: regulator-max77620: convert to DT schema
      https://git.kernel.org/broonie/regulator/c/881dd6b2ff82

All being well this means that it will be integrated into the linux-next
tree (usually sometime in the next 24 hours) and sent to Linus during
the next merge window (or sooner if it is a bug fix), however if
problems are discovered then the patch may be dropped or reverted.

You may get further e-mails resulting from automated or manual testing
and review of the tree, please engage with people reporting problems and
send followup patches addressing any issues that are reported if needed.

If any updates are required or you are submitting further changes they
should be sent as incremental updates against current git, existing
patches will not be replaced.

Please add any relevant lists and maintainers to the CCs when replying
to this mail.

Thanks,
Mark


^ permalink raw reply

* Re: [PATCH v2] ASoC: dt-bindings: ti,tas2552: Add sound-dai-cells
From: Mark Brown @ 2026-04-06 12:10 UTC (permalink / raw)
  To: devicetree, Marek Vasut
  Cc: Baojun Xu, Conor Dooley, Kevin Lu, Krzysztof Kozlowski,
	Liam Girdwood, Rob Herring, Shenghao Ding, linux-kernel,
	linux-sound
In-Reply-To: <20260405234502.154227-1-marex@nabladev.com>

On Mon, 06 Apr 2026 01:44:35 +0200, Marek Vasut wrote:
> ASoC: dt-bindings: ti,tas2552: Add sound-dai-cells

Applied to

   https://git.kernel.org/pub/scm/linux/kernel/git/broonie/sound.git for-7.0

Thanks!

[1/1] ASoC: dt-bindings: ti,tas2552: Add sound-dai-cells
      https://git.kernel.org/broonie/sound/c/5075d08e72af

All being well this means that it will be integrated into the linux-next
tree (usually sometime in the next 24 hours) and sent to Linus during
the next merge window (or sooner if it is a bug fix), however if
problems are discovered then the patch may be dropped or reverted.

You may get further e-mails resulting from automated or manual testing
and review of the tree, please engage with people reporting problems and
send followup patches addressing any issues that are reported if needed.

If any updates are required or you are submitting further changes they
should be sent as incremental updates against current git, existing
patches will not be replaced.

Please add any relevant lists and maintainers to the CCs when replying
to this mail.

Thanks,
Mark


^ permalink raw reply

* Re: (subset) [PATCH v2 0/7] Enable Bluetooth and WiFi on Fairphone (Gen. 6)
From: Mark Brown @ 2026-04-06 13:17 UTC (permalink / raw)
  To: Bjorn Andersson, Konrad Dybcio, Rob Herring, Krzysztof Kozlowski,
	Conor Dooley, Alexander Koskovich, Liam Girdwood,
	Bartosz Golaszewski, Marcel Holtmann, Luiz Augusto von Dentz,
	Balakrishna Godavarthi, Rocky Liao, Johannes Berg, Jeff Johnson,
	Luca Weiss
  Cc: ~postmarketos/upstreaming, phone-devel, linux-arm-msm,
	linux-kernel, devicetree, linux-bluetooth, linux-wireless, ath11k,
	Dmitry Baryshkov
In-Reply-To: <20260403-milos-fp6-bt-wifi-v2-0-393322b27c5f@fairphone.com>

On Fri, 03 Apr 2026 15:52:46 +0200, Luca Weiss wrote:
> Enable Bluetooth and WiFi on Fairphone (Gen. 6)
> 
> Add the required bits to enable Bluetooth and WiFi on the Milos
> SoC-based Fairphone (Gen. 6) smartphone.

Applied to

   https://git.kernel.org/pub/scm/linux/kernel/git/broonie/regulator.git for-7.1

Thanks!

[1/7] regulator: dt-bindings: qcom,qca6390-pmu: Document WCN6755 PMU
      https://git.kernel.org/broonie/regulator/c/b043657c35e5

All being well this means that it will be integrated into the linux-next
tree (usually sometime in the next 24 hours) and sent to Linus during
the next merge window (or sooner if it is a bug fix), however if
problems are discovered then the patch may be dropped or reverted.

You may get further e-mails resulting from automated or manual testing
and review of the tree, please engage with people reporting problems and
send followup patches addressing any issues that are reported if needed.

If any updates are required or you are submitting further changes they
should be sent as incremental updates against current git, existing
patches will not be replaced.

Please add any relevant lists and maintainers to the CCs when replying
to this mail.

Thanks,
Mark


^ permalink raw reply

* Re: [PATCH v2] dt-bindings: remoteproc: qcom: Drop types for firmware-name
From: Bjorn Andersson @ 2026-04-06 15:10 UTC (permalink / raw)
  To: Rob Herring, Shawn Guo
  Cc: Mathieu Poirier, Krzysztof Kozlowski, Conor Dooley,
	Stephan Gerhold, Sibi Sankar, Bartosz Golaszewski,
	Manivannan Sadhasivam, linux-arm-msm, linux-remoteproc,
	devicetree, linux-kernel
In-Reply-To: <20260309123357.1911586-1-shengchao.guo@oss.qualcomm.com>


On Mon, 09 Mar 2026 20:33:57 +0800, Shawn Guo wrote:
> The type of firmware-name is already defined by core schemas.  Drop it
> from individual bindings that have either a redundant definition or
> an override as string type.  For the later cases, constrain the number
> of expected firmware names to 1.
> 
> 

Applied, thanks!

[1/1] dt-bindings: remoteproc: qcom: Drop types for firmware-name
      commit: 74eb6cd91aef968ee792575f10b438ae2f2a2bb2

Best regards,
-- 
Bjorn Andersson <andersson@kernel.org>

^ permalink raw reply

* Re: [PATCH 0/2] remoteproc: qcom: pas: Add supoport for Eliza ADSP
From: Bjorn Andersson @ 2026-04-06 15:09 UTC (permalink / raw)
  To: Mathieu Poirier, Rob Herring, Krzysztof Kozlowski, Conor Dooley,
	Luca Weiss, Abel Vesa
  Cc: linux-arm-msm, linux-remoteproc, devicetree, linux-kernel
In-Reply-To: <20260327-eliza-remoteproc-adsp-v1-0-1c46c5e5f809@oss.qualcomm.com>


On Fri, 27 Mar 2026 18:18:37 +0200, Abel Vesa wrote:
> Add support for ADSP remoteproc found on Qualcomm Eliza SoC.
> The rest of the remoteprocs will come later.
> 
> Instead of adding a dedicated bindings schema, just reuse the Milos one
> as bindings are exactly the same.
> 
> Then, just add the compatible and reuse the SM8550 configuration in the
> driver.
> 
> [...]

Applied, thanks!

[1/2] dt-bindings: remoteproc: qcom,milos-pas: Document Eliza ADSP
      commit: 7cf2f07f949c999f8c0349d1fa3f1f0e69854469
[2/2] remoteproc: qcom: pas: Add Eliza ADSP support
      commit: 56c1ec524284805da0181bc6e9ca656c0091b201

Best regards,
-- 
Bjorn Andersson <andersson@kernel.org>

^ permalink raw reply

* Re: [PATCH v3 00/15] firmware: qcom: Add OP-TEE PAS service support
From: Bjorn Andersson @ 2026-04-06 15:09 UTC (permalink / raw)
  To: Sumit Garg
  Cc: linux-arm-msm, devicetree, dri-devel, freedreno, linux-media,
	netdev, linux-wireless, ath12k, linux-remoteproc, konradybcio,
	robh, krzk+dt, conor+dt, robin.clark, sean, akhilpo, lumag,
	abhinav.kumar, jesszhan0024, marijn.suijten, airlied, simona,
	vikash.garodia, dikshita.agarwal, bod, mchehab, elder,
	andrew+netdev, davem, edumazet, kuba, pabeni, jjohnson,
	mathieu.poirier, trilokkumar.soni, mukesh.ojha, pavan.kondeti,
	jorge.ramirez, tonyh, vignesh.viswanathan, srinivas.kandagatla,
	amirreza.zarrabi, jens.wiklander, op-tee, apurupa, skare,
	harshal.dev, linux-kernel, Sumit Garg
In-Reply-To: <20260327131043.627120-1-sumit.garg@kernel.org>

On Fri, Mar 27, 2026 at 06:40:28PM +0530, Sumit Garg wrote:
> From: Sumit Garg <sumit.garg@oss.qualcomm.com>
> 
> Qcom platforms has the legacy of using non-standard SCM calls
> splintered over the various kernel drivers. These SCM calls aren't
> compliant with the standard SMC calling conventions which is a
> prerequisite to enable migration to the FF-A specifications from Arm.
> 

Please get our colleagues involved in this discussion, because this
non-SCM interface does not match the direction we are taking.

Regards,
Bjorn

> OP-TEE as an alternative trusted OS to Qualcomm TEE (QTEE) can't
> support these non-standard SCM calls. And even for newer architectures
> using S-EL2 with Hafnium support, QTEE won't be able to support SCM
> calls either with FF-A requirements coming in. And with both OP-TEE
> and QTEE drivers well integrated in the TEE subsystem, it makes further
> sense to reuse the TEE bus client drivers infrastructure.
> 
> The added benefit of TEE bus infrastructure is that there is support
> for discoverable/enumerable services. With that client drivers don't
> have to manually invoke a special SCM call to know the service status.
> 
> So enable the generic Peripheral Authentication Service (PAS) provided
> by the firmware. It acts as the common layer with different TZ
> backends plugged in whether it's an SCM implementation or a proper
> TEE bus based PAS service implementation.
> 
> The TEE PAS service ABI is designed to be extensible with additional API
> as PTA_QCOM_PAS_CAPABILITIES. This allows to accommodate any future
> extensions of the PAS service needed while still maintaining backwards
> compatibility.
> 
> Currently OP-TEE support is being added to provide the backend PAS
> service implementation which can be found as part of this PR [1].
> This implementation has been tested on Kodiak/RB3Gen2 board with lemans
> EVK board being the next target. In addition to that WIN/IPQ targets
> planning to use OP-TEE will use this service too. Surely the backwards
> compatibility is maintained and tested for SCM backend.
> 
> Patch summary:
> - Patch #1: adds Kodiak EL2 overlay since boot stack with TF-A/OP-TEE
>   only allow UEFI and Linux to boot in EL2.
> - Patch #2: adds generic PAS service.
> - Patch #3: migrates SCM backend to generic PAS service.
> - Patch #4: adds TEE/OP-TEE backend for generic PAS service.
> - Patch #5-#13: migrates all client drivers to generic PAS service.
> - Patch #14: drops legacy PAS SCM exported APIs.
> 
> The patch-set is based on v7.0-rc5 tag and can be found in git tree here
> [2].
> 
> Merge strategy:
> 
> It is expected due to APIs dependency, the entire patch-set to go via
> the Qcom tree. All other subsystem maintainers, it will be great if I
> can get acks for the corresponding subsystem patches.
> 
> [1] https://github.com/OP-TEE/optee_os/pull/7721
> [2] https://git.kernel.org/pub/scm/linux/kernel/git/sumit.garg/linux.git/log/?h=qcom-pas-v3
> 
> ---
> Changes in v3:
> - Incorporated some style and misc. comments for patch #2, #3 and #4.
> - Add QCOM_PAS Kconfig dependency for various subsystems.
> - Switch from pseudo TA to proper TA invoke commands.
> 
> Changes in v2:
> - Fixed kernel doc warnings.
> - Polish commit message and comments for patch #2.
> - Pass proper PAS ID in set_remote_state API for media firmware drivers.
> - Added Maintainer entry and dropped MODULE_AUTHOR.
> 
> Mukesh Ojha (1):
>   arm64: dts: qcom: kodiak: Add EL2 overlay
> 
> Sumit Garg (14):
>   firmware: qcom: Add a generic PAS service
>   firmware: qcom_scm: Migrate to generic PAS service
>   firmware: qcom: Add a PAS TEE service
>   remoteproc: qcom_q6v5_pas: Switch over to generic PAS TZ APIs
>   remoteproc: qcom_q6v5_mss: Switch to generic PAS TZ APIs
>   soc: qcom: mdtloader: Switch to generic PAS TZ APIs
>   remoteproc: qcom_wcnss: Switch to generic PAS TZ APIs
>   remoteproc: qcom: Select QCOM_PAS generic service
>   drm/msm: Switch to generic PAS TZ APIs
>   media: qcom: Switch to generic PAS TZ APIs
>   net: ipa: Switch to generic PAS TZ APIs
>   wifi: ath12k: Switch to generic PAS TZ APIs
>   firmware: qcom_scm: Remove SCM PAS wrappers
>   MAINTAINERS: Add maintainer entry for Qualcomm PAS TZ service
> 
>  MAINTAINERS                                   |   9 +
>  arch/arm64/boot/dts/qcom/Makefile             |   2 +
>  arch/arm64/boot/dts/qcom/kodiak-el2.dtso      |  35 ++
>  drivers/firmware/qcom/Kconfig                 |  19 +
>  drivers/firmware/qcom/Makefile                |   2 +
>  drivers/firmware/qcom/qcom_pas.c              | 288 +++++++++++
>  drivers/firmware/qcom/qcom_pas.h              |  50 ++
>  drivers/firmware/qcom/qcom_pas_tee.c          | 478 ++++++++++++++++++
>  drivers/firmware/qcom/qcom_scm.c              | 302 ++++-------
>  drivers/gpu/drm/msm/Kconfig                   |   1 +
>  drivers/gpu/drm/msm/adreno/a5xx_gpu.c         |   4 +-
>  drivers/gpu/drm/msm/adreno/adreno_gpu.c       |  11 +-
>  drivers/media/platform/qcom/iris/Kconfig      |  25 +-
>  .../media/platform/qcom/iris/iris_firmware.c  |   9 +-
>  drivers/media/platform/qcom/venus/Kconfig     |   1 +
>  drivers/media/platform/qcom/venus/firmware.c  |  11 +-
>  drivers/net/ipa/Kconfig                       |   2 +-
>  drivers/net/ipa/ipa_main.c                    |  13 +-
>  drivers/net/wireless/ath/ath12k/Kconfig       |   2 +-
>  drivers/net/wireless/ath/ath12k/ahb.c         |   8 +-
>  drivers/remoteproc/Kconfig                    |   1 +
>  drivers/remoteproc/qcom_q6v5_mss.c            |   5 +-
>  drivers/remoteproc/qcom_q6v5_pas.c            |  51 +-
>  drivers/remoteproc/qcom_wcnss.c               |  12 +-
>  drivers/soc/qcom/mdt_loader.c                 |  12 +-
>  include/linux/firmware/qcom/qcom_pas.h        |  43 ++
>  include/linux/firmware/qcom/qcom_scm.h        |  29 --
>  include/linux/soc/qcom/mdt_loader.h           |   6 +-
>  28 files changed, 1114 insertions(+), 317 deletions(-)
>  create mode 100644 arch/arm64/boot/dts/qcom/kodiak-el2.dtso
>  create mode 100644 drivers/firmware/qcom/qcom_pas.c
>  create mode 100644 drivers/firmware/qcom/qcom_pas.h
>  create mode 100644 drivers/firmware/qcom/qcom_pas_tee.c
>  create mode 100644 include/linux/firmware/qcom/qcom_pas.h
> 
> -- 
> 2.51.0
> 

^ permalink raw reply

* Re: [PATCH v4 5/7] remoteproc: core: set recovery_disabled when doing rproc_add()
From: Bjorn Andersson @ 2026-04-06 15:04 UTC (permalink / raw)
  To: Jingyi Wang
  Cc: Dmitry Baryshkov, Bartosz Golaszewski, aiqun.yu, tingwei.zhang,
	trilok.soni, yijie.yang, linux-arm-msm, linux-remoteproc,
	devicetree, linux-kernel, Mathieu Poirier, Rob Herring,
	Krzysztof Kozlowski, Conor Dooley, Manivannan Sadhasivam,
	Luca Weiss, Konrad Dybcio
In-Reply-To: <ef36a946-ba7d-4588-b94f-4287f3ea6105@oss.qualcomm.com>

On Thu, Mar 19, 2026 at 01:44:48PM +0800, Jingyi Wang wrote:
> 
> 
> On 3/19/2026 1:23 PM, Dmitry Baryshkov wrote:
> > On Thu, Mar 19, 2026 at 12:36:15PM +0800, Jingyi Wang wrote:
> > > 
> > > 
> > > On 3/13/2026 10:37 AM, Dmitry Baryshkov wrote:
> > > > On Wed, Mar 11, 2026 at 01:39:50AM -0700, Bartosz Golaszewski wrote:
> > > > > On Wed, 11 Mar 2026 03:11:42 +0100, Dmitry Baryshkov
> > > > > <dmitry.baryshkov@oss.qualcomm.com> said:
> > > > > > On Tue, Mar 10, 2026 at 06:50:30AM -0700, Bartosz Golaszewski wrote:
> > > > > > > 
> > > > > > > Ideally things like this would be passed to the rproc core in some kind of a
> > > > > > > config structure and only set when registration succeeds. This looks to me
> > > > > > > like papering over the real issue and I think it's still racy as there's no
> > > > > > > true synchronization.
> > > > > > > 
> > > > > > > Wouldn't it be better to take rproc->lock for the entire duration of
> > > > > > > rproc_add()? It's already initialized in rproc_alloc().
> > > > > > 
> > > > > > It would still be racy as rproc_trigger_recovery() is called outside of
> > > > > > the lock. Instead the error cleanup path (and BTW, rproc_del() path too)
> > > > > > must explicitly call cancel_work_sync() on the crash_handler work (and
> > > > > > any other work items that can be scheduled).
> > > > > > 
> > > > > 
> > > > > This looks weird TBH. For example: rproc_crash_handler_work() takes the lock,
> > > > > but releases it right before calling inspecting rproc->recovery_disabled and
> > > > > calling rproc_trigger_recovery(). It looks wrong, I think it should keep the
> > > > > lock and rptoc_trigger_recovery() should enforce it being taken before the
> > > > > call.
> > > > 
> > > > Yes. Nevertheless the driver should cancel the work too.
> > > > 
> > > 
> > > Hi Dmitry & Bartosz,
> > > 
> > > rproc_crash_handler_work() may call rproc_trigger_recovery() and
> > > rproc_add() may call rproc_boot(), both the function have already
> > > hold the lock. And the lock cannot protect resources like glink_subdev
> > > in the patch.
> > > 
> > > And there is a possible case for cancel_work, rproc_add tear down call
> > > cancel work and wait for the work finished, the reboot run successfully,
> > > and the tear down continued and the resources all released, including sysfs
> > > and glink_subdev.
> > > 
> > > Indeed recovery_disabled is kind of hacky.
> > > The root cause for this issue is that for remoteproc with RPROC_OFFLINE
> > > state, the rproc_start will be called asynchronously, but for the remoteproc
> > > with RPROC_DETACHED, the attach function is called directly, the failure
> > > in this path will cause the rproc_add() fail and the resource release.
> > > I think the current patch can be dropped, we are thinking about make rproc_attach
> > > called asynchronously to avoid this race.
> > 
> > Isn't this patch necessary for SoCCP bringup? If not, why did you
> > include it into the series?
> > 
> yes, will squash to soccp patch in next versoin.

I'm sorry, but that doesn't make sense to me.

The SoCCP patch adds support for attaching SoCCP. This change tries to
address a generic problem shared across all remoteproc drivers (that
does attach?).

I think you should interpret Dmitry's comment as "why is this part of
this series, please fix this problem in a separate series".

Regards,
Bjorn

^ permalink raw reply

* Re: [PATCH v6 4/4] iio: adc: ad4691: add SPI offload support
From: David Lechner @ 2026-04-06 15:02 UTC (permalink / raw)
  To: Sabau, Radu bogdan, Lars-Peter Clausen, Hennerich, Michael,
	Jonathan Cameron, Sa, Nuno, Andy Shevchenko, Rob Herring,
	Krzysztof Kozlowski, Conor Dooley, Uwe Kleine-König,
	Liam Girdwood, Mark Brown, Linus Walleij, Bartosz Golaszewski,
	Philipp Zabel, Jonathan Corbet, Shuah Khan
  Cc: linux-iio@vger.kernel.org, devicetree@vger.kernel.org,
	linux-kernel@vger.kernel.org, linux-pwm@vger.kernel.org,
	linux-gpio@vger.kernel.org, linux-doc@vger.kernel.org
In-Reply-To: <LV9PR03MB8414CB15DEC3EBBDB8F5FDD0F75DA@LV9PR03MB8414.namprd03.prod.outlook.com>

On 4/6/26 9:16 AM, Sabau, Radu bogdan wrote:
> 
> 
>> -----Original Message-----
>> From: David Lechner <dlechner@baylibre.com>
>> Sent: Monday, April 6, 2026 4:44 PM
> 
> ...
> 
>>>
>>> This is bad documentation on my part. "channel byte" isn't used anymore,
>>> this is previous version behaviour. Right now, only 16-bits worth of actual
>>> channel data are used.
>>>
>> Then why do we need the shift if there is no other data? Can't we rework
>> the SPI message so that there is no shift?
> 
> I thought the shift is needed since DMA size is 32 bits, and value comes on the
> upper word 16 bits, not on the lower ones as for CNV Burst.

That should only happen if we are reading 32-bits instead of 16 bits.
We should be able to set up the SPI xfers so that we only read 16 bits.

> 
> Manual Mode layout: TX [CMD_HI CMD_LO DUMMY DUMMY], RX [DATA_HI DATA_LO DUMMY DUMMY]

> CNV Burst layout: TX [REG_HI REG_LO DUMMY DUMMY], RX [DUMMY DUMMY DATA_HI DATA_LO]

This can be split in two xfers.

CNV Burst layout:
	TX [REG_HI REG_LO]
	RX [DATA_HI DATA_LO]

And we could even set bits_per_word to 16 so that the data is CPU
endian instead of big endian when doing SPI offloading.


^ permalink raw reply

* Re: [PATCH v4 6/7] remoteproc: qcom: pas: Add late attach support for subsystems
From: Bjorn Andersson @ 2026-04-06 14:59 UTC (permalink / raw)
  To: Jingyi Wang
  Cc: Mathieu Poirier, Rob Herring, Krzysztof Kozlowski, Conor Dooley,
	Manivannan Sadhasivam, Luca Weiss, Bartosz Golaszewski,
	Konrad Dybcio, aiqun.yu, tingwei.zhang, trilok.soni, yijie.yang,
	linux-arm-msm, linux-remoteproc, devicetree, linux-kernel,
	Gokul Krishna Krishnakumar
In-Reply-To: <20260310-knp-soccp-v4-6-0a91575e0e7e@oss.qualcomm.com>

On Tue, Mar 10, 2026 at 03:03:22AM -0700, Jingyi Wang wrote:
> From: Gokul Krishna Krishnakumar <gokul.krishnakumar@oss.qualcomm.com>
> 
> Subsystems can be brought out of reset by entities such as bootloaders.
> As the irq enablement could be later than subsystem bring up, the state
> of subsystem should be checked by reading SMP2P bits and performing ping
> test.
> 
> A new qcom_pas_attach() function is introduced. if a crash state is
> detected for the subsystem, rproc_report_crash() is called. If the
> subsystem is ready either at the first check or within a 5-second timeout
> and the ping is successful, it will be marked as "attached". The ready
> state could be set by either ready interrupt or handover interrupt.
> 

The whole use case of early booting SoCCP is to get the charger and USB
Type-C running early - so that charging and USB Type-C works in UEFI.

If SMP2P indicates that it was booted, but it's still not there...then
there's no reason to wait another 5 seconds - it's not there.

> If "early_boot" is set by kernel but "subsys_booted" is not completed
> within the timeout, It could be the early boot feature is not supported
> by other entities. In this case, the state will be marked as RPROC_OFFLINE
> so that the PAS driver can load the firmware and start the remoteproc. As
> the running state is set once attach function is called, the watchdog or
> fatal interrupt received can be handled correctly.
> 
> Signed-off-by: Gokul Krishna Krishnakumar <gokul.krishnakumar@oss.qualcomm.com>
> Co-developed-by: Jingyi Wang <jingyi.wang@oss.qualcomm.com>
> Signed-off-by: Jingyi Wang <jingyi.wang@oss.qualcomm.com>
[..]
> diff --git a/drivers/remoteproc/qcom_q6v5_pas.c b/drivers/remoteproc/qcom_q6v5_pas.c
[..]
> +static int qcom_pas_attach(struct rproc *rproc)
[..]
> +	if (!ret)
> +		ret = irq_get_irqchip_state(pas->q6v5.ready_irq,
> +					    IRQCHIP_STATE_LINE_LEVEL, &ready_state);
> +
> +	/*
> +	 * smp2p allocate irq entry can be delayed, irq_get_irqchip_state will get -ENODEV,

This on the other hand, sounds like a bug in the smp2p driver. If we can
acquire the interrupt without getting EPROBE_DEFER, then we should not
get -ENODEV when reading the irq state.

> +	 * the 5 seconds timeout is set to wait for this, after the entry is allocated, smp2p
> +	 * will call the qcom_smp2p_intr and complete the timeout in the ISR.

If this indeed is the problem you're working around with the 5 second
delay - then stop. Fix the issue instead!

Also, this comment conflicts with the reasoning for the ping and the 5
second thing in the commit message.

Regards,
Bjorn

> +	 */
> +	if (unlikely(ret == -ENODEV) || unlikely(!ready_state)) {
> +		ret = wait_for_completion_timeout(&pas->q6v5.subsys_booted,
> +						  msecs_to_jiffies(EARLY_ATTACH_TIMEOUT_MS));
> +
> +		/*
> +		 * The bootloader may not support early boot, mark the state as
> +		 * RPROC_OFFLINE so that the PAS driver can load the firmware and
> +		 * start the remoteproc.
> +		 */
> +		if (!ret) {
> +			dev_err(pas->dev, "Timeout on waiting for subsystem interrupt\n");
> +			pas->rproc->state = RPROC_OFFLINE;
> +			ret = -ETIMEDOUT;
> +			goto disable_running;
> +		}
> +
> +		/* Only ping the subsystem if ready_state is set */
> +		ret = irq_get_irqchip_state(pas->q6v5.ready_irq,
> +					    IRQCHIP_STATE_LINE_LEVEL, &ready_state);
> +
> +		if (ret)
> +			goto disable_running;
> +
> +		if (!ready_state) {
> +			ret = -EINVAL;
> +			goto disable_running;
> +		}
> +	}
> +
> +	ret = qcom_q6v5_ping_subsystem(&pas->q6v5);
> +
> +	if (ret) {
> +		dev_err(pas->dev, "Failed to ping subsystem, assuming device crashed\n");
> +		rproc_report_crash(rproc, RPROC_FATAL_ERROR);
> +		goto disable_running;
> +	}
> +
> +	pas->q6v5.handover_issued = true;
> +
> +	return 0;
> +
> +disable_running:
> +	pas->q6v5.running = false;
> +
> +	return ret;
> +}
> +
>  static const struct rproc_ops qcom_pas_ops = {
>  	.unprepare = qcom_pas_unprepare,
>  	.start = qcom_pas_start,
> @@ -518,6 +603,7 @@ static const struct rproc_ops qcom_pas_ops = {
>  	.parse_fw = qcom_pas_parse_firmware,
>  	.load = qcom_pas_load,
>  	.panic = qcom_pas_panic,
> +	.attach = qcom_pas_attach,
>  };
>  
>  static const struct rproc_ops qcom_pas_minidump_ops = {
> @@ -823,7 +909,7 @@ static int qcom_pas_probe(struct platform_device *pdev)
>  	pas->proxy_pd_count = ret;
>  
>  	ret = qcom_q6v5_init(&pas->q6v5, pdev, rproc, desc->crash_reason_smem,
> -			     desc->load_state, qcom_pas_handover);
> +			     desc->load_state, desc->early_boot, qcom_pas_handover);
>  	if (ret)
>  		goto detach_proxy_pds;
>  
> @@ -855,6 +941,15 @@ static int qcom_pas_probe(struct platform_device *pdev)
>  
>  	pas->pas_ctx->use_tzmem = rproc->has_iommu;
>  	pas->dtb_pas_ctx->use_tzmem = rproc->has_iommu;
> +
> +	if (pas->q6v5.early_boot) {
> +		ret = qcom_q6v5_ping_subsystem_init(&pas->q6v5, pdev);
> +		if (ret)
> +			dev_warn(&pdev->dev, "Falling back to firmware load\n");
> +		else
> +			pas->rproc->state = RPROC_DETACHED;
> +	}
> +
>  	ret = rproc_add(rproc);
>  	if (ret)
>  		goto remove_ssr_sysmon;
> diff --git a/drivers/remoteproc/qcom_q6v5_wcss.c b/drivers/remoteproc/qcom_q6v5_wcss.c
> index c27200159a88..859141589ed7 100644
> --- a/drivers/remoteproc/qcom_q6v5_wcss.c
> +++ b/drivers/remoteproc/qcom_q6v5_wcss.c
> @@ -1011,7 +1011,7 @@ static int q6v5_wcss_probe(struct platform_device *pdev)
>  	if (ret)
>  		return ret;
>  
> -	ret = qcom_q6v5_init(&wcss->q6v5, pdev, rproc, desc->crash_reason_smem, NULL, NULL);
> +	ret = qcom_q6v5_init(&wcss->q6v5, pdev, rproc, desc->crash_reason_smem, NULL, false, NULL);
>  	if (ret)
>  		return ret;
>  
> 
> -- 
> 2.25.1
> 

^ permalink raw reply

* Re: [PATCH v4 2/4] arm64: Kconfig: Add ARCH_HPE platform
From: Krzysztof Kozlowski @ 2026-04-06 14:52 UTC (permalink / raw)
  To: nick.hawkins, catalin.marinas, will, robh, krzk+dt, conor+dt
  Cc: linux-arm-kernel, devicetree, linux-kernel
In-Reply-To: <20260406143821.1843621-3-nick.hawkins@hpe.com>

On 06/04/2026 16:38, nick.hawkins@hpe.com wrote:
> From: Nick Hawkins <nick.hawkins@hpe.com>
> 
> From: Nick Hawkins <nick.hawkins@hpe.com>

You have duplicated From fields. Not sure if this will apply correctly.
> 
> Add the ARCH_HPE config for HPE ARM64 BMC SoCs to Kconfig.platforms.
> 
> Signed-off-by: Nick Hawkins <nick.hawkins@hpe.com>
> Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@oss.qualcomm.com>


Best regards,
Krzysztof

^ permalink raw reply

* [PATCH] dt-bindings: thermal: idle: Correct node name in the example
From: Krzysztof Kozlowski @ 2026-04-06 14:51 UTC (permalink / raw)
  To: Rafael J. Wysocki, Daniel Lezcano, Zhang Rui, Lukasz Luba,
	Rob Herring, Krzysztof Kozlowski, Conor Dooley, linux-pm,
	devicetree, linux-kernel
  Cc: Krzysztof Kozlowski

Thermal bindings expect the node name with all the zones to be named
'thermal-zones' (hyphen instead of underscore) and also DTS coding style
is not to use underscores for node names, so adjust the example code.

Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@oss.qualcomm.com>
---
 Documentation/devicetree/bindings/thermal/thermal-idle.yaml | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/Documentation/devicetree/bindings/thermal/thermal-idle.yaml b/Documentation/devicetree/bindings/thermal/thermal-idle.yaml
index 1b77d542a7b8..357699b50c68 100644
--- a/Documentation/devicetree/bindings/thermal/thermal-idle.yaml
+++ b/Documentation/devicetree/bindings/thermal/thermal-idle.yaml
@@ -101,7 +101,7 @@ examples:
 
         /* ... */
 
-        thermal_zones {
+        thermal-zones {
             cpu_thermal: cpu {
                 polling-delay-passive = <100>;
                 polling-delay = <1000>;
-- 
2.51.0


^ permalink raw reply related

* Re: Devicetree spec: Specifying /cpus/cpu@* unit address format?
From: Vivian Wang @ 2026-04-06 14:46 UTC (permalink / raw)
  To: Rob Herring, David Gibson
  Cc: devicetree-spec, Krzysztof Kozlowski, Conor Dooley, Paul Walmsley,
	Palmer Dabbelt, Alexandre Ghiti, Chen Wang, Inochi Amaoto,
	devicetree, linux-riscv, sophgo
In-Reply-To: <CAL_JsqJFv3+UJ-bjLGk0i7Wc+spsowCrqQZ_s3P4gN8r1W-Q-w@mail.gmail.com>

On 4/6/26 20:48, Rob Herring wrote:
> On Sat, Apr 4, 2026 at 11:43 PM David Gibson
> <david@gibson.dropbear.id.au> wrote:
>> On Fri, Apr 03, 2026 at 06:06:17PM +0800, Vivian Wang wrote:
>>> (Also posted at: https://github.com/devicetree-org/devicetree-specification/issues/86 )
>>>
>>> Hi all,
>>>
>>> Presently, there seems to be some confusion in the community about the
>>> format of unit addresses for "/cpus/cpu@*" nodes for a CPU with ID > 9, e.g.
>>>
>>>     cpu@??? {
>>>         reg = <10>;
>>>         /* reg = <0xa>; */ /* This should be equivalent */
>>>     }
>>>
>>>
>>> Should this be a decimal "cpu@10", or hexadecimal "cpu@a"? I can't find
>>> any explicit specification.
>> It should be hex.  That's a general convention for unit addresses.
>> Before flattened trees, OF essentially never used decimal
>> representations of things.
> The only decimal usage in FDT were mistakes.

Thanks for this. This is clear enough for me.

> Rather than worrying about what the spec says, please worry about what
> the tools check.

Since, as you two said, there is an established convention, I agree that
convention is enough here.

Thanks,
Vivian "dramforever" Wang


^ permalink raw reply

* Re: [PATCH v6 2/2] dt-bindings: embedded-controller: Add synology microp devices
From: Krzysztof Kozlowski @ 2026-04-06 14:42 UTC (permalink / raw)
  To: Markus Probst
  Cc: Hans de Goede, Ilpo Järvinen, Bryan O'Donoghue,
	Lee Jones, Pavel Machek, Miguel Ojeda, Boqun Feng, Gary Guo,
	Björn Roy Baron, Benno Lossin, Andreas Hindborg, Alice Ryhl,
	Trevor Gross, Danilo Krummrich, Rob Herring, Krzysztof Kozlowski,
	Conor Dooley, Greg Kroah-Hartman, platform-driver-x86, linux-leds,
	devicetree, linux-kernel, rust-for-linux
In-Reply-To: <63fbd1a5cddc5b79302056fa7b01a790aca8ba8e.camel@posteo.de>

On 06/04/2026 16:22, Markus Probst wrote:
> On Mon, 2026-04-06 at 09:59 +0200, Krzysztof Kozlowski wrote:
>> On Sun, Apr 05, 2026 at 07:36:29PM +0200, Markus Probst wrote:
>>> Add the Synology Microp devicetree bindings. Those devices are
>>> microcontrollers found on Synology NAS devices. They are connected to a
>>> serial port on the host device.
>>>
>>> Those devices are used to control certain LEDs, fan speeds, a beeper, to
>>> handle buttons, fan failures and to properly shutdown and reboot the
>>> device.
>>>
>>> This includes the following compatible ids:
>>>  - synology,ds923p-microp
>>>  - synology,ds918p-microp
>>>  - synology,ds214play-microp
>>>  - synology,ds225p-microp
>>>  - synology,ds425p-microp
>>>  - synology,ds710p-microp
>>>  - synology,ds1010p-microp
>>>  - synology,ds723p-microp
>>>  - synology,ds1522p-microp
>>>  - synology,rs422p-microp
>>>  - synology,ds725p-microp
>>>  - synology,ds118-microp
>>>  - synology,ds124-microp
>>>  - synology,ds223-microp
>>>  - synology,ds223j-microp
>>>  - synology,ds1823xsp-microp
>>>  - synology,rs822p-microp
>>>  - synology,rs1221p-microp
>>>  - synology,rs1221rpp-microp
>>>  - synology,ds925p-microp
>>>  - synology,ds1525p-microp
>>>  - synology,ds1825p-microp
>>
>> Drop, we see this in the diff.
> A prior review commit suggested I should add them [1].
> So only synology,ds923p-microp in the Subject then?

I do not see how this list resolves my comment. Really, explain my how
listing part of binding answers WHY they are not compatible?


> 
> [1]
> https://lore.kernel.org/all/20260330-delicate-sassy-mayfly-ebcca7@quoll/
> 
>>
>>>
>>> Signed-off-by: Markus Probst <markus.probst@posteo.de>
>>> ---
>>>  .../synology,ds923p-microp.yaml                    | 112 +++++++++++++++++++++
>>>  MAINTAINERS                                        |   1 +
>>>  2 files changed, 113 insertions(+)
>>>
>>> diff --git a/Documentation/devicetree/bindings/embedded-controller/synology,ds923p-microp.yaml b/Documentation/devicetree/bindings/embedded-controller/synology,ds923p-microp.yaml
>>> new file mode 100644
>>> index 000000000000..4518e9b74be1
>>> --- /dev/null
>>> +++ b/Documentation/devicetree/bindings/embedded-controller/synology,ds923p-microp.yaml
>>> @@ -0,0 +1,112 @@
>>> +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
>>> +%YAML 1.2
>>> +---
>>> +$id: http://devicetree.org/schemas/embedded-controller/synology,ds923p-microp.yaml#
>>> +$schema: http://devicetree.org/meta-schemas/core.yaml#
>>> +
>>> +title: Synology NAS on-board Microcontroller
>>> +
>>> +maintainers:
>>> +  - Markus Probst <markus.probst@posteo.de>
>>> +
>>> +description: |
>>> +  Synology Microp is a microcontroller found in Synology NAS devices.
>>> +  It is connected to a serial port on the host device.
>>> +
>>> +  It is necessary to properly shutdown and reboot the NAS device and
>>> +  provides additional functionality such as led control, fan speed control,
>>> +  a beeper and buttons on the NAS device.
>>> +
>>> +properties:
>>> +  compatible:
>>> +    enum:
>>> +      - synology,ds923p-microp
>>> +      - synology,ds918p-microp
>>> +      - synology,ds214play-microp
>>> +      - synology,ds225p-microp
>>> +      - synology,ds425p-microp
>>> +      - synology,ds710p-microp
>>> +      - synology,ds1010p-microp
>>> +      - synology,ds723p-microp
>>> +      - synology,ds1522p-microp
>>> +      - synology,rs422p-microp
>>> +      - synology,ds725p-microp
>>> +      - synology,ds118-microp
>>> +      - synology,ds124-microp
>>> +      - synology,ds223-microp
>>> +      - synology,ds223j-microp
>>> +      - synology,ds1823xsp-microp
>>> +      - synology,rs822p-microp
>>> +      - synology,rs1221p-microp
>>> +      - synology,rs1221rpp-microp
>>> +      - synology,ds925p-microp
>>> +      - synology,ds1525p-microp
>>> +      - synology,ds1825p-microp
>>
>> So we already talked about this and you were told to use compatibility.
>> Your driver clearly states several of these are compatible, so I am
>> confused that I do not see it expressed here.
> The driver does not have all functionality implemented yet.

Either this drivers works or not. If it works, explain me how they are
not compatible.

> 
> A few examples of differences not yet visible in the driver:
> - synology,ds214play-microp is the only model in the current list to
> have an cpu fan
> - 4 of the models are arm based and need a different shutdown behaviour
> - different amount of fans (already present in the binding via fan-
> failure-gpios)
> 
> I could try to group them together, but Synology does not document the
> exact difference between them.
> 
> As Rob mentioned [2], I need to be able to handle unexpected
> differences without qurik properties.

I did not object that.


Best regards,
Krzysztof

^ permalink raw reply

* [PATCH v9 2/3] hwmon: ltc4283: Add support for the LTC4283 Swap Controller
From: Nuno Sá via B4 Relay @ 2026-04-06 14:31 UTC (permalink / raw)
  To: linux-gpio, linux-hwmon, devicetree, linux-doc
  Cc: Guenter Roeck, Rob Herring, Krzysztof Kozlowski, Conor Dooley,
	Jonathan Corbet, Linus Walleij, Bartosz Golaszewski
In-Reply-To: <20260406-ltc4283-support-v9-0-b66cfc749261@analog.com>

From: Nuno Sá <nuno.sa@analog.com>

Support the LTC4283 Hot Swap Controller. The device features programmable
current limit with foldback and independently adjustable inrush current to
optimize the MOSFET safe operating area (SOA). The SOA timer limits MOSFET
temperature rise for reliable protection against overstresses.

An I2C interface and onboard ADC allow monitoring of board current,
voltage, power, energy, and fault status.

Signed-off-by: Nuno Sá <nuno.sa@analog.com>
---
 Documentation/hwmon/index.rst   |    1 +
 Documentation/hwmon/ltc4283.rst |  266 ++++++
 MAINTAINERS                     |    1 +
 drivers/hwmon/Kconfig           |   12 +
 drivers/hwmon/Makefile          |    1 +
 drivers/hwmon/ltc4283.c         | 1808 +++++++++++++++++++++++++++++++++++++++
 6 files changed, 2089 insertions(+)

diff --git a/Documentation/hwmon/index.rst b/Documentation/hwmon/index.rst
index 199f35a75282..d54dda83ab6e 100644
--- a/Documentation/hwmon/index.rst
+++ b/Documentation/hwmon/index.rst
@@ -144,6 +144,7 @@ Hardware Monitoring Kernel Drivers
    ltc4260
    ltc4261
    ltc4282
+   ltc4283
    ltc4286
    macsmc-hwmon
    max127
diff --git a/Documentation/hwmon/ltc4283.rst b/Documentation/hwmon/ltc4283.rst
new file mode 100644
index 000000000000..ba88445e45f4
--- /dev/null
+++ b/Documentation/hwmon/ltc4283.rst
@@ -0,0 +1,266 @@
+.. SPDX-License-Identifier: GPL-2.0-only
+
+Kernel drivers ltc4283
+==========================================
+
+Supported chips:
+
+  * Analog Devices LTC4283
+
+    Prefix: 'ltc4283'
+
+    Addresses scanned: -
+
+    Datasheet:
+
+        https://www.analog.com/media/en/technical-documentation/data-sheets/ltc4283.pdf
+
+Author: Nuno Sá <nuno.sa@analog.com>
+
+Description
+___________
+
+The LTC4283 negative voltage hot swap controller drives an external N-channel
+MOSFET to allow a board to be safely inserted and removed from a live backplane.
+The device features programmable current limit with foldback and independently
+adjustable inrush current to optimize the MOSFET safe operating area (SOA). The
+SOA timer limits MOSFET temperature rise for reliable protection against
+overstresses. An I2C interface and onboard gear-shift ADC allow monitoring of
+board current, voltage, power, energy, and fault status.  Additional features
+respond to input UV/OV, interrupt the host when a fault has occurred, notify
+when output power is good, detect insertion of a board, turn off the MOSFET
+if an external supply monitor fails to indicate power good within a timeout
+period, and auto-reboot after a programmable delay following a host commanded
+turn-off.
+
+Sysfs entries
+_____________
+
+The following attributes are supported. Limits are read-write and all the other
+attributes are read-only. Note that the VADIOx channels might not be available
+if the ADIO pins are used as GPIOs (naturally also affects the respective
+differential channels).
+
+======================= ==========================================
+in0_lcrit_alarm         Critical Undervoltage alarm
+in0_crit_alarm          Critical Overvoltage alarm
+in0_label		Channel label (VIN)
+
+in1_input		Output voltage (mV).
+in1_min			Undervoltage threshold
+in1_max			Overvoltage threshold
+in1_lowest		Lowest measured voltage
+in1_highest		Highest measured voltage
+in1_reset_history	Write 1 to reset history.
+in1_min_alarm		Undervoltage alarm
+in1_max_alarm		Overvoltage alarm
+in1_label		Channel label (VPWR)
+
+in2_input		Output voltage (mV).
+in2_min			Undervoltage threshold
+in2_max			Overvoltage threshold
+in2_lowest		Lowest measured voltage
+in2_highest		Highest measured voltage
+in2_reset_history	Write 1 to reset history.
+in2_min_alarm		Undervoltage alarm
+in2_max_alarm		Overvoltage alarm
+in2_enable		Enable/Disable monitoring.
+in2_label		Channel label (VADI1)
+
+in3_input		Output voltage (mV).
+in3_min			Undervoltage threshold
+in3_max			Overvoltage threshold
+in3_lowest		Lowest measured voltage
+in3_highest		Highest measured voltage
+in3_reset_history	Write 1 to reset history.
+in3_min_alarm		Undervoltage alarm
+in3_max_alarm		Overvoltage alarm
+in3_enable		Enable/Disable monitoring.
+in3_label		Channel label (VADI2)
+
+in4_input		Output voltage (mV).
+in4_min			Undervoltage threshold
+in4_max			Overvoltage threshold
+in4_lowest		Lowest measured voltage
+in4_highest		Highest measured voltage
+in4_reset_history	Write 1 to reset history.
+in4_min_alarm		Undervoltage alarm
+in4_max_alarm		Overvoltage alarm
+in4_enable		Enable/Disable monitoring.
+in4_label		Channel label (VADI3)
+
+in5_input		Output voltage (mV).
+in5_min			Undervoltage threshold
+in5_max			Overvoltage threshold
+in5_lowest		Lowest measured voltage
+in5_highest		Highest measured voltage
+in5_reset_history	Write 1 to reset history.
+in5_min_alarm		Undervoltage alarm
+in5_max_alarm		Overvoltage alarm
+in5_enable		Enable/Disable monitoring.
+in5_label		Channel label (VADI4)
+
+in6_input		Output voltage (mV).
+in6_min			Undervoltage threshold
+in6_max			Overvoltage threshold
+in6_lowest		Lowest measured voltage
+in6_highest		Highest measured voltage
+in6_reset_history	Write 1 to reset history.
+in6_min_alarm		Undervoltage alarm
+in6_max_alarm		Overvoltage alarm
+in6_enable		Enable/Disable monitoring.
+in6_label		Channel label (VADIO1)
+
+in7_input		Output voltage (mV).
+in7_min			Undervoltage threshold
+in7_max			Overvoltage threshold
+in7_lowest		Lowest measured voltage
+in7_highest		Highest measured voltage
+in7_reset_history	Write 1 to reset history.
+in7_min_alarm		Undervoltage alarm
+in7_max_alarm		Overvoltage alarm
+in7_enable		Enable/Disable monitoring.
+in7_label		Channel label (VADIO2)
+
+in8_input		Output voltage (mV).
+in8_min			Undervoltage threshold
+in8_max			Overvoltage threshold
+in8_lowest		Lowest measured voltage
+in8_highest		Highest measured voltage
+in8_reset_history	Write 1 to reset history.
+in8_min_alarm		Undervoltage alarm
+in8_max_alarm		Overvoltage alarm
+in8_enable		Enable/Disable monitoring.
+in8_label		Channel label (VADIO3)
+
+in9_input		Output voltage (mV).
+in9_min			Undervoltage threshold
+in9_max			Overvoltage threshold
+in9_lowest		Lowest measured voltage
+in9_highest		Highest measured voltage
+in9_reset_history	Write 1 to reset history.
+in9_min_alarm		Undervoltage alarm
+in9_max_alarm		Overvoltage alarm
+in9_enable		Enable/Disable monitoring.
+in9_label		Channel label (VADIO4)
+
+in10_input		Output voltage (mV).
+in10_min		Undervoltage threshold
+in10_max		Overvoltage threshold
+in10_lowest		Lowest measured voltage
+in10_highest		Highest measured voltage
+in10_reset_history	Write 1 to reset history.
+in10_min_alarm		Undervoltage alarm
+in10_max_alarm		Overvoltage alarm
+in10_enable		Enable/Disable monitoring.
+in10_label		Channel label (DRNS)
+
+in11_input		Output voltage (mV).
+in11_min		Undervoltage threshold
+in11_max		Overvoltage threshold
+in11_lowest		Lowest measured voltage
+in11_highest		Highest measured voltage
+in11_reset_history	Write 1 to reset history.
+			Also clears fet bad and short fault logs.
+in11_min_alarm		Undervoltage alarm
+in11_max_alarm		Overvoltage alarm
+in11_enable		Enable/Disable monitoring
+in11_fault		Failure in the MOSFET. Either bad or shorted FET.
+in11_label		Channel label (DRAIN)
+
+in12_input		Output voltage (mV).
+in12_min		Undervoltage threshold
+in12_max		Overvoltage threshold
+in12_lowest		Lowest measured voltage
+in12_highest		Highest measured voltage
+in12_reset_history	Write 1 to reset history.
+in12_min_alarm		Undervoltage alarm
+in12_max_alarm		Overvoltage alarm
+in12_enable		Enable/Disable monitoring.
+in12_label		Channel label (ADIN2-ADIN1)
+
+in13_input		Output voltage (mV).
+in13_min		Undervoltage threshold
+in13_max		Overvoltage threshold
+in13_lowest		Lowest measured voltage
+in13_highest		Highest measured voltage
+in13_reset_history	Write 1 to reset history.
+in13_min_alarm		Undervoltage alarm
+in13_max_alarm		Overvoltage alarm
+in13_enable		Enable/Disable monitoring.
+in13_label		Channel label (ADIN4-ADIN3)
+
+in14_input		Output voltage (mV).
+in14_min		Undervoltage threshold
+in14_max		Overvoltage threshold
+in14_lowest		Lowest measured voltage
+in14_highest		Highest measured voltage
+in14_reset_history	Write 1 to reset history.
+in14_min_alarm		Undervoltage alarm
+in14_max_alarm		Overvoltage alarm
+in14_enable		Enable/Disable monitoring.
+in14_label		Channel label (ADIO2-ADIO1)
+
+in15_input		Output voltage (mV).
+in15_min		Undervoltage threshold
+in15_max		Overvoltage threshold
+in15_lowest		Lowest measured voltage
+in15_highest		Highest measured voltage
+in15_reset_history	Write 1 to reset history.
+in15_min_alarm		Undervoltage alarm
+in15_max_alarm		Overvoltage alarm
+in15_enable		Enable/Disable monitoring.
+in15_label		Channel label (ADIO4-ADIO3)
+
+curr1_input		Sense current (mA)
+curr1_min		Undercurrent threshold
+curr1_max		Overcurrent threshold
+curr1_lowest		Lowest measured current
+curr1_highest		Highest measured current
+curr1_reset_history	Write 1 to reset curr1 history.
+			Also clears overcurrent fault logs.
+curr1_min_alarm		Undercurrent alarm
+curr1_max_alarm		Overcurrent alarm
+curr1_crit_alarm        Critical Overcurrent alarm
+curr1_label		Channel label (ISENSE)
+
+power1_input		Power (in uW)
+power1_min		Low power threshold
+power1_max		High power threshold
+power1_input_lowest	Historical minimum power use
+power1_input_highest	Historical maximum power use
+power1_reset_history	Write 1 to reset power1 history.
+			Also clears power fault logs.
+power1_min_alarm	Low power alarm
+power1_max_alarm	High power alarm
+power1_label		Channel label (Power)
+
+energy1_input		Measured energy over time (in microJoule)
+energy1_enable		Enable/Disable Energy accumulation
+======================= ==========================================
+
+DebugFs entries
+_______________
+
+The chip also has a fault log register where failures can be logged. Hence,
+as these are logging events, we give access to them in debugfs. Note that
+even if some failure is detected in these logs, it does necessarily mean
+that the failure is still present. As mentioned in the proper Sysfs entries,
+these logs can be cleared by writing in the proper reset_history attribute.
+
+.. warning:: The debugfs interface is subject to change without notice
+             and is only available when the kernel is compiled with
+             ``CONFIG_DEBUG_FS`` defined.
+
+``/sys/kernel/debug/i2c/i2c-[X]/[X]-addr/``
+contains the following attributes:
+
+=======================		==========================================
+power1_failed_fault_log		Set to 1 by a power1 fault occurring.
+power1_good_input_fault_log	Set to 1 by a power1 good input fault occurring at PGIO3.
+in11_fet_short_fault_log	Set to 1 when a FET-short fault occurs.
+in11_fet_bad_fault_log		Set to 1 when a FET-BAD fault occurs.
+in0_lcrit_fault_log		Set to 1 by a VIN undervoltage fault occurring.
+in0_crit_fault_log		Set to 1 by a VIN overvoltage fault occurring.
+curr1_crit_fault_log		Set to 1 by an overcurrent fault occurring.
+======================= 	==========================================
diff --git a/MAINTAINERS b/MAINTAINERS
index 3f727d7fdfa4..a63833b6fe8b 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -15166,6 +15166,7 @@ M:	Nuno Sá <nuno.sa@analog.com>
 L:	linux-hwmon@vger.kernel.org
 S:	Supported
 F:	Documentation/devicetree/bindings/hwmon/adi,ltc4283.yaml
+F:	drivers/hwmon/ltc4283.c
 
 LTC4286 HARDWARE MONITOR DRIVER
 M:	Delphine CC Chiu <Delphine_CC_Chiu@Wiwynn.com>
diff --git a/drivers/hwmon/Kconfig b/drivers/hwmon/Kconfig
index fb847ab40ab4..4d9f500ae6ee 100644
--- a/drivers/hwmon/Kconfig
+++ b/drivers/hwmon/Kconfig
@@ -1157,6 +1157,18 @@ config SENSORS_LTC4282
 	  This driver can also be built as a module. If so, the module will
 	  be called ltc4282.
 
+config SENSORS_LTC4283
+	tristate "Analog Devices LTC4283"
+	depends on I2C
+	select REGMAP_I2C
+	select AUXILIARY_BUS
+	help
+	  If you say yes here you get support for Analog Devices LTC4283
+	  Negative Voltage Hot Swap Controller I2C interface.
+
+	  This driver can also be built as a module. If so, the module will
+	  be called ltc4283.
+
 config SENSORS_LTQ_CPUTEMP
 	bool "Lantiq cpu temperature sensor driver"
 	depends on SOC_XWAY
diff --git a/drivers/hwmon/Makefile b/drivers/hwmon/Makefile
index 0fce31b43eb1..b9d7b0287b9c 100644
--- a/drivers/hwmon/Makefile
+++ b/drivers/hwmon/Makefile
@@ -147,6 +147,7 @@ obj-$(CONFIG_SENSORS_LTC4245)	+= ltc4245.o
 obj-$(CONFIG_SENSORS_LTC4260)	+= ltc4260.o
 obj-$(CONFIG_SENSORS_LTC4261)	+= ltc4261.o
 obj-$(CONFIG_SENSORS_LTC4282)	+= ltc4282.o
+obj-$(CONFIG_SENSORS_LTC4283)	+= ltc4283.o
 obj-$(CONFIG_SENSORS_LTQ_CPUTEMP) += ltq-cputemp.o
 obj-$(CONFIG_SENSORS_MACSMC_HWMON)	+= macsmc-hwmon.o
 obj-$(CONFIG_SENSORS_MAX1111)	+= max1111.o
diff --git a/drivers/hwmon/ltc4283.c b/drivers/hwmon/ltc4283.c
new file mode 100644
index 000000000000..2a2674a55167
--- /dev/null
+++ b/drivers/hwmon/ltc4283.c
@@ -0,0 +1,1808 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Analog Devices LTC4283 I2C Negative Voltage Hot Swap Controller (HWMON)
+ *
+ * Copyright 2025 Analog Devices Inc.
+ */
+#include <linux/auxiliary_bus.h>
+#include <linux/bitfield.h>
+#include <linux/bitmap.h>
+#include <linux/bitops.h>
+#include <linux/bits.h>
+
+#include <linux/debugfs.h>
+#include <linux/device.h>
+#include <linux/device/devres.h>
+#include <linux/hwmon.h>
+#include <linux/i2c.h>
+#include <linux/math.h>
+#include <linux/math64.h>
+#include <linux/minmax.h>
+#include <linux/module.h>
+
+#include <linux/mod_devicetable.h>
+#include <linux/overflow.h>
+#include <linux/property.h>
+#include <linux/regmap.h>
+#include <linux/unaligned.h>
+#include <linux/units.h>
+
+#define LTC4283_SYSTEM_STATUS		0x00
+#define LTC4283_FAULT_STATUS		0x03
+#define   LTC4283_OV_MASK		BIT(0)
+#define   LTC4283_UV_MASK		BIT(1)
+#define   LTC4283_OC_MASK		BIT(2)
+#define   LTC4283_FET_BAD_MASK		BIT(3)
+#define   LTC4283_FET_SHORT_MASK	BIT(6)
+#define LTC4283_FAULT_LOG		0x04
+#define   LTC4283_OV_FAULT_MASK		BIT(0)
+#define   LTC4283_UV_FAULT_MASK		BIT(1)
+#define   LTC4283_OC_FAULT_MASK		BIT(2)
+#define   LTC4283_FET_BAD_FAULT_MASK	BIT(3)
+#define   LTC4283_PGI_FAULT_MASK	BIT(4)
+#define   LTC4283_PWR_FAIL_FAULT_MASK	BIT(5)
+#define   LTC4283_FET_SHORT_FAULT_MASK	BIT(6)
+#define LTC4283_ADC_ALM_LOG_1		0x05
+#define   LTC4283_POWER_LOW_ALM		BIT(0)
+#define   LTC4283_POWER_HIGH_ALM	BIT(1)
+#define   LTC4283_SENSE_LOW_ALM		BIT(4)
+#define   LTC4283_SENSE_HIGH_ALM	BIT(5)
+#define LTC4283_ADC_ALM_LOG_2		0x06
+#define LTC4283_ADC_ALM_LOG_3		0x07
+#define LTC4283_ADC_ALM_LOG_4		0x08
+#define LTC4283_ADC_ALM_LOG_5		0x09
+#define LTC4283_CONTROL_1		0x0a
+#define   LTC4283_RW_PAGE_MASK		BIT(0)
+#define   LTC4283_PIGIO2_ACLB_MASK	BIT(2)
+#define   LTC4283_PWRGD_RST_CTRL_MASK	BIT(3)
+#define   LTC4283_FET_BAD_OFF_MASK	BIT(4)
+#define   LTC4283_THERM_TMR_MASK	BIT(5)
+#define   LTC4283_DVDT_MASK		BIT(6)
+#define LTC4283_CONTROL_2		0x0b
+#define   LTC4283_OV_RETRY_MASK		BIT(0)
+#define   LTC4283_UV_RETRY_MASK		BIT(1)
+#define   LTC4283_OC_RETRY_MASK		GENMASK(3, 2)
+#define   LTC4283_FET_BAD_RETRY_MASK	GENMASK(5, 4)
+#define   LTC4283_EXT_FAULT_RETRY_MASK	BIT(7)
+#define LTC4283_RESERVED_OC		0x0c
+#define LTC4283_CONFIG_1		0x0d
+#define   LTC4283_FB_MASK		GENMASK(3, 2)
+#define   LTC4283_ILIM_MASK		GENMASK(7, 4)
+#define LTC4283_CONFIG_2		0x0e
+#define   LTC4283_COOLING_DL_MASK	GENMASK(3, 1)
+#define   LTC4283_FTBD_DL_MASK		GENMASK(5, 4)
+#define LTC4283_CONFIG_3		0x0f
+#define   LTC4283_VPWR_DRNS_MASK	BIT(6)
+#define   LTC4283_EXTFLT_TURN_OFF_MASK	BIT(7)
+#define LTC4283_PGIO_CONFIG		0x10
+#define   LTC4283_PGIO1_CFG_MASK	GENMASK(1, 0)
+#define   LTC4283_PGIO2_CFG_MASK	GENMASK(3, 2)
+#define   LTC4283_PGIO3_CFG_MASK	GENMASK(5, 4)
+#define   LTC4283_PGIO4_CFG_MASK	GENMASK(7, 6)
+#define LTC4283_PGIO_CONFIG_2		0x11
+#define   LTC4283_ADC_MASK		GENMASK(2, 0)
+#define LTC4283_ADC_SELECT(c)		(0x13 + (c) / 8)
+#define   LTC4283_ADC_SELECT_MASK(c)	BIT((c) % 8)
+#define LTC4283_SENSE_MIN_TH		0x1b
+#define LTC4283_SENSE_MAX_TH		0x1c
+#define LTC4283_VPWR_MIN_TH		0x1d
+#define LTC4283_VPWR_MAX_TH		0x1e
+#define LTC4283_POWER_MIN_TH		0x1f
+#define LTC4283_POWER_MAX_TH		0x20
+#define LTC4283_ADC_2_MIN_TH(c)		(0x21 + (c) * 2)
+#define LTC4283_ADC_2_MAX_TH(c)		(0x22 + (c) * 2)
+#define LTC4283_ADC_2_MIN_TH_DIFF(c)	(0x39 + (c) * 2)
+#define LTC4283_ADC_2_MAX_TH_DIFF(c)	(0x3a + (c) * 2)
+#define LTC4283_SENSE			0x41
+#define LTC4283_SENSE_MIN		0x42
+#define LTC4283_SENSE_MAX		0x43
+#define LTC4283_VPWR			0x44
+#define LTC4283_VPWR_MIN		0x45
+#define LTC4283_VPWR_MAX		0x46
+#define LTC4283_POWER			0x47
+#define LTC4283_POWER_MIN		0x48
+#define LTC4283_POWER_MAX		0x49
+#define LTC4283_RESERVED_68		0x68
+#define LTC4283_RESERVED_6D		0x6D
+/* get channels from ADC 2 */
+#define LTC4283_ADC_2(c)		(0x4a + (c) * 3)
+#define LTC4283_ADC_2_MIN(c)		(0x4b + (c) * 3)
+#define LTC4283_ADC_2_MAX(c)		(0x4c + (c) * 3)
+#define LTC4283_ADC_2_DIFF(c)		(0x6e + (c) * 3)
+#define LTC4283_ADC_2_MIN_DIFF(c)	(0x6f + (c) * 3)
+#define LTC4283_ADC_2_MAX_DIFF(c)	(0x70 + (c) * 3)
+#define LTC4283_ENERGY			0x7a
+#define LTC4283_METER_CONTROL		0x84
+#define   LTC4283_INTEGRATE_I_MASK	BIT(0)
+#define   LTC4283_METER_HALT_MASK	BIT(6)
+#define LTC4283_RESERVED_86		0x86
+#define LTC4283_RESERVED_8F		0x8F
+#define LTC4283_FAULT_LOG_CTRL		0x90
+#define   LTC4283_FAULT_LOG_EN_MASK	BIT(7)
+#define LTC4283_RESERVED_91		0x91
+#define LTC4283_RESERVED_A1		0xA1
+#define LTC4283_RESERVED_A3		0xA3
+#define LTC4283_RESERVED_AC		0xAC
+#define LTC4283_POWER_PLAY_MSB		0xE7
+#define LTC4283_POWER_PLAY_LSB		0xE8
+#define LTC4283_RESERVED_F1		0xF1
+#define LTC4283_RESERVED_FF		0xFF
+
+/* also applies for differential channels */
+#define LTC4283_ADC1_FS_uV		32768
+#define LTC4283_ADC2_FS_mV		2048
+#define LTC4283_TCONV_uS		64103
+#define LTC4283_VILIM_MIN_uV		15000
+#define LTC4283_VILIM_MAX_uV		30000
+#define LTC4283_VILIM_RANGE	\
+	(LTC4283_VILIM_MAX_uV - LTC4283_VILIM_MIN_uV + 1)
+
+#define LTC4283_PGIO_FUNC_GPIO		2
+#define LTC4283_PGIO2_FUNC_ACLB		3
+
+/*
+ * Maximum value for rsense in nano ohms. The reasoning for this value is that
+ * it's the max value for which multiplying by 256 does not overflow long on
+ * 32bits. For the minimum value, is a sane minimum rsense for which power_max
+ * does not overflow 32bits.
+ */
+#define LTC4283_MAX_RSENSE	1677721599
+#define LTC4283_MIN_RSENSE	50000
+
+/* voltage channels */
+enum {
+	LTC4283_CHAN_VIN,
+	LTC4283_CHAN_VPWR,
+	LTC4283_CHAN_ADI_1,
+	LTC4283_CHAN_ADI_2,
+	LTC4283_CHAN_ADI_3,
+	LTC4283_CHAN_ADI_4,
+	LTC4283_CHAN_ADIO_1,
+	LTC4283_CHAN_ADIO_2,
+	LTC4283_CHAN_ADIO_3,
+	LTC4283_CHAN_ADIO_4,
+	LTC4283_CHAN_DRNS,
+	LTC4283_CHAN_DRAIN,
+	/* differential channels */
+	LTC4283_CHAN_ADIN12,
+	LTC4283_CHAN_ADIN34,
+	LTC4283_CHAN_ADIO12,
+	LTC4283_CHAN_ADIO34,
+	LTC4283_CHAN_MAX
+};
+
+/* Just for ease of use on the regmap  */
+#define LTC4283_ADIO34_MAX \
+	LTC4283_ADC_2_MAX_DIFF(LTC4283_CHAN_ADIO34 - LTC4283_CHAN_ADIN12)
+
+struct ltc4283_hwmon {
+	struct regmap *map;
+	struct i2c_client *client;
+	unsigned long gpio_mask;
+	unsigned long ch_enable_mask;
+	/* in microwatt */
+	long power_max;
+	/* in millivolt */
+	u32 vsense_max;
+	/* in tenths of microohm*/
+	u32 rsense;
+	bool energy_en;
+	bool ext_fault;
+};
+
+static int ltc4283_read_voltage_word(const struct ltc4283_hwmon *st,
+				     u32 reg, u32 fs, long *val)
+{
+	unsigned int __raw;
+	int ret;
+
+	ret = regmap_read(st->map, reg, &__raw);
+	if (ret)
+		return ret;
+
+	*val = DIV_ROUND_CLOSEST(__raw * fs, BIT(16));
+	return 0;
+}
+
+static int ltc4283_read_voltage_byte(const struct ltc4283_hwmon *st,
+				     u32 reg, u32 fs, long *val)
+{
+	int ret;
+	u32 in;
+
+	ret = regmap_read(st->map, reg, &in);
+	if (ret)
+		return ret;
+
+	*val = DIV_ROUND_CLOSEST(in * fs, BIT(8));
+	return 0;
+}
+
+static u32 ltc4283_in_reg(u32 attr, u32 channel)
+{
+	switch (attr) {
+	case hwmon_in_input:
+		if (channel == LTC4283_CHAN_VPWR)
+			return LTC4283_VPWR;
+		if (channel >= LTC4283_CHAN_ADI_1 && channel <= LTC4283_CHAN_DRAIN)
+			return LTC4283_ADC_2(channel - LTC4283_CHAN_ADI_1);
+		return LTC4283_ADC_2_DIFF(channel - LTC4283_CHAN_ADIN12);
+	case hwmon_in_highest:
+		if (channel == LTC4283_CHAN_VPWR)
+			return LTC4283_VPWR_MAX;
+		if (channel >= LTC4283_CHAN_ADI_1 && channel <= LTC4283_CHAN_DRAIN)
+			return LTC4283_ADC_2_MAX(channel - LTC4283_CHAN_ADI_1);
+		return LTC4283_ADC_2_MAX_DIFF(channel - LTC4283_CHAN_ADIN12);
+	case hwmon_in_lowest:
+		if (channel == LTC4283_CHAN_VPWR)
+			return LTC4283_VPWR_MIN;
+		if (channel >= LTC4283_CHAN_ADI_1 && channel <= LTC4283_CHAN_DRAIN)
+			return LTC4283_ADC_2_MIN(channel - LTC4283_CHAN_ADI_1);
+		return LTC4283_ADC_2_MIN_DIFF(channel - LTC4283_CHAN_ADIN12);
+	case hwmon_in_max:
+		if (channel == LTC4283_CHAN_VPWR)
+			return LTC4283_VPWR_MAX_TH;
+		if (channel >= LTC4283_CHAN_ADI_1 && channel <= LTC4283_CHAN_DRAIN)
+			return LTC4283_ADC_2_MAX_TH(channel - LTC4283_CHAN_ADI_1);
+		return LTC4283_ADC_2_MAX_TH_DIFF(channel - LTC4283_CHAN_ADIN12);
+	default:
+		if (channel == LTC4283_CHAN_VPWR)
+			return LTC4283_VPWR_MIN_TH;
+		if (channel >= LTC4283_CHAN_ADI_1 && channel <= LTC4283_CHAN_DRAIN)
+			return LTC4283_ADC_2_MIN_TH(channel - LTC4283_CHAN_ADI_1);
+		return LTC4283_ADC_2_MIN_TH_DIFF(channel - LTC4283_CHAN_ADIN12);
+	}
+}
+
+static int ltc4283_read_in_vals(const struct ltc4283_hwmon *st,
+				u32 attr, u32 channel, long *val)
+{
+	u32 reg = ltc4283_in_reg(attr, channel);
+	int ret;
+
+	if (channel < LTC4283_CHAN_ADIN12) {
+		if (attr != hwmon_in_max && attr != hwmon_in_min)
+			return ltc4283_read_voltage_word(st, reg,
+							 LTC4283_ADC2_FS_mV,
+							 val);
+
+		return ltc4283_read_voltage_byte(st, reg,
+						 LTC4283_ADC2_FS_mV, val);
+	}
+
+	if (attr != hwmon_in_max && attr != hwmon_in_min)
+		ret = ltc4283_read_voltage_word(st, reg,
+						LTC4283_ADC1_FS_uV, val);
+	else
+		ret = ltc4283_read_voltage_byte(st, reg,
+						LTC4283_ADC1_FS_uV, val);
+	if (ret)
+		return ret;
+
+	*val = DIV_ROUND_CLOSEST(*val, MILLI);
+	return 0;
+}
+
+static int ltc4283_read_alarm(struct ltc4283_hwmon *st, u32 reg,
+			      u32 mask, long *val)
+{
+	u32 alarm;
+	int ret;
+
+	ret = regmap_read(st->map, reg, &alarm);
+	if (ret)
+		return ret;
+
+	*val = !!(alarm & mask);
+
+	/* If not status/fault logs, clear the alarm after reading it. */
+	if (reg != LTC4283_FAULT_STATUS && reg != LTC4283_FAULT_LOG)
+		return regmap_clear_bits(st->map, reg, mask);
+
+	return 0;
+}
+
+static int ltc4283_read_in_alarm(struct ltc4283_hwmon *st, u32 channel,
+				 bool max_alm, long *val)
+{
+	if (channel == LTC4283_VPWR)
+		return ltc4283_read_alarm(st, LTC4283_ADC_ALM_LOG_1,
+					  BIT(2 + max_alm), val);
+
+	if (channel >= LTC4283_CHAN_ADI_1 && channel <= LTC4283_CHAN_ADI_4) {
+		u32 bit = (channel - LTC4283_CHAN_ADI_1) * 2;
+		/*
+		 * Lower channels go to higher bits. We also want to go +1 down
+		 * in the min_alarm case.
+		 */
+		return ltc4283_read_alarm(st, LTC4283_ADC_ALM_LOG_2,
+					  BIT(7 - bit - !max_alm), val);
+	}
+
+	if (channel >= LTC4283_CHAN_ADIO_1 && channel <= LTC4283_CHAN_ADIO_4) {
+		u32 bit = (channel - LTC4283_CHAN_ADIO_1) * 2;
+
+		return ltc4283_read_alarm(st, LTC4283_ADC_ALM_LOG_3,
+					  BIT(7 - bit - !max_alm), val);
+	}
+
+	if (channel >= LTC4283_CHAN_ADIN12 && channel <= LTC4283_CHAN_ADIO34) {
+		u32 bit = (channel - LTC4283_CHAN_ADIN12) * 2;
+
+		return ltc4283_read_alarm(st, LTC4283_ADC_ALM_LOG_5,
+					  BIT(7 - bit - !max_alm), val);
+	}
+
+	if (channel == LTC4283_CHAN_DRNS)
+		return ltc4283_read_alarm(st, LTC4283_ADC_ALM_LOG_4,
+					  BIT(6 + max_alm), val);
+
+	return ltc4283_read_alarm(st, LTC4283_ADC_ALM_LOG_4, BIT(4 + max_alm),
+				  val);
+}
+
+static int ltc4283_read_in(struct ltc4283_hwmon *st, u32 attr, u32 channel,
+			   long *val)
+{
+	switch (attr) {
+	case hwmon_in_input:
+		if (!test_bit(channel, &st->ch_enable_mask))
+			return -ENODATA;
+
+		return ltc4283_read_in_vals(st, attr, channel, val);
+	case hwmon_in_highest:
+	case hwmon_in_lowest:
+	case hwmon_in_max:
+	case hwmon_in_min:
+		return ltc4283_read_in_vals(st, attr, channel, val);
+	case hwmon_in_max_alarm:
+		return ltc4283_read_in_alarm(st, channel, true, val);
+	case hwmon_in_min_alarm:
+		return ltc4283_read_in_alarm(st, channel, false, val);
+	case hwmon_in_crit_alarm:
+		return ltc4283_read_alarm(st, LTC4283_FAULT_STATUS,
+					  LTC4283_OV_MASK, val);
+	case hwmon_in_lcrit_alarm:
+		return ltc4283_read_alarm(st, LTC4283_FAULT_STATUS,
+					  LTC4283_UV_MASK, val);
+	case hwmon_in_fault:
+		/*
+		 * We report failure if we detect either a fer_bad or a
+		 * fet_short in the status register.
+		 */
+		return ltc4283_read_alarm(st, LTC4283_FAULT_STATUS,
+					  LTC4283_FET_BAD_MASK | LTC4283_FET_SHORT_MASK, val);
+	case hwmon_in_enable:
+		*val = test_bit(channel, &st->ch_enable_mask);
+		return 0;
+	default:
+		return -EOPNOTSUPP;
+	}
+	return 0;
+}
+
+static int ltc4283_read_current_word(const struct ltc4283_hwmon *st, u32 reg,
+				     long *val)
+{
+	u64 temp = (u64)LTC4283_ADC1_FS_uV * DECA * MILLI;
+	unsigned int __raw;
+	int ret;
+
+	ret = regmap_read(st->map, reg, &__raw);
+	if (ret)
+		return ret;
+
+	*val = DIV64_U64_ROUND_CLOSEST(__raw * temp,
+				       BIT_ULL(16) * st->rsense);
+
+	return 0;
+}
+
+static int ltc4283_read_current_byte(const struct ltc4283_hwmon *st, u32 reg,
+				     long *val)
+{
+	u64 temp = (u64)LTC4283_ADC1_FS_uV * DECA * MILLI;
+	u32 curr;
+	int ret;
+
+	ret = regmap_read(st->map, reg, &curr);
+	if (ret)
+		return ret;
+
+	*val = DIV_ROUND_CLOSEST_ULL(curr * temp, BIT(8) * st->rsense);
+	return 0;
+}
+
+static int ltc4283_read_curr(struct ltc4283_hwmon *st, u32 attr, long *val)
+{
+	switch (attr) {
+	case hwmon_curr_input:
+		return ltc4283_read_current_word(st, LTC4283_SENSE, val);
+	case hwmon_curr_highest:
+		return ltc4283_read_current_word(st, LTC4283_SENSE_MAX, val);
+	case hwmon_curr_lowest:
+		return ltc4283_read_current_word(st, LTC4283_SENSE_MIN, val);
+	case hwmon_curr_max:
+		return ltc4283_read_current_byte(st, LTC4283_SENSE_MAX_TH, val);
+	case hwmon_curr_min:
+		return ltc4283_read_current_byte(st, LTC4283_SENSE_MIN_TH, val);
+	case hwmon_curr_max_alarm:
+		return ltc4283_read_alarm(st, LTC4283_ADC_ALM_LOG_1,
+					  LTC4283_SENSE_HIGH_ALM, val);
+	case hwmon_curr_min_alarm:
+		return ltc4283_read_alarm(st, LTC4283_ADC_ALM_LOG_1,
+					  LTC4283_SENSE_LOW_ALM, val);
+	case hwmon_curr_crit_alarm:
+		return ltc4283_read_alarm(st, LTC4283_FAULT_STATUS,
+					  LTC4283_OC_MASK, val);
+	default:
+		return -EOPNOTSUPP;
+	}
+}
+
+static int ltc4283_read_power_word(const struct ltc4283_hwmon *st,
+				   u32 reg, long *val)
+{
+	u64 temp = (u64)LTC4283_ADC1_FS_uV * LTC4283_ADC2_FS_mV * DECA * MILLI;
+	unsigned int __raw;
+	int ret;
+
+	ret = regmap_read(st->map, reg, &__raw);
+	if (ret)
+		return ret;
+
+	/*
+	 * Power is given by:
+	 *     P = CODE(16b) * 32.768mV * 2.048V / (2^16 * Rsense)
+	 */
+	*val = DIV64_U64_ROUND_CLOSEST(temp * __raw, BIT_ULL(16) * st->rsense);
+
+	return 0;
+}
+
+static int ltc4283_read_power_byte(const struct ltc4283_hwmon *st,
+				   u32 reg, long *val)
+{
+	u64 temp = (u64)LTC4283_ADC1_FS_uV * LTC4283_ADC2_FS_mV * DECA * MILLI;
+	u32 power;
+	int ret;
+
+	ret = regmap_read(st->map, reg, &power);
+	if (ret)
+		return ret;
+
+	*val = DIV_ROUND_CLOSEST_ULL(power * temp, BIT(8) * st->rsense);
+
+	return 0;
+}
+
+static int ltc4283_read_power(struct ltc4283_hwmon *st, u32 attr, long *val)
+{
+	switch (attr) {
+	case hwmon_power_input:
+		return ltc4283_read_power_word(st, LTC4283_POWER, val);
+	case hwmon_power_input_highest:
+		return ltc4283_read_power_word(st, LTC4283_POWER_MAX, val);
+	case hwmon_power_input_lowest:
+		return ltc4283_read_power_word(st, LTC4283_POWER_MIN, val);
+	case hwmon_power_max_alarm:
+		return ltc4283_read_alarm(st, LTC4283_ADC_ALM_LOG_1,
+					  LTC4283_POWER_HIGH_ALM, val);
+	case hwmon_power_min_alarm:
+		return ltc4283_read_alarm(st, LTC4283_ADC_ALM_LOG_1,
+					  LTC4283_POWER_LOW_ALM, val);
+	case hwmon_power_max:
+		return ltc4283_read_power_byte(st, LTC4283_POWER_MAX_TH, val);
+	case hwmon_power_min:
+		return ltc4283_read_power_byte(st, LTC4283_POWER_MIN_TH, val);
+	default:
+		return -EOPNOTSUPP;
+	}
+}
+
+static int ltc4283_read_energy(struct ltc4283_hwmon *st, u32 attr, s64 *val)
+{
+	u64 temp = LTC4283_ADC1_FS_uV * LTC4283_ADC2_FS_mV, energy, temp_2;
+	u8 raw[8] = {};
+	int ret;
+
+	if (!st->energy_en)
+		return -ENODATA;
+
+	ret = i2c_smbus_read_i2c_block_data(st->client, LTC4283_ENERGY, 6, raw);
+	if (ret < 0)
+		return ret;
+	if (ret != 6)
+		return -EIO;
+
+	energy = get_unaligned_be64(raw) >> 16;
+
+	/*
+	 * The formula for energy is given by:
+	 *	E = CODE(48b) * 32.768mV * 2.048V * Tconv / 2^24 * Rsense
+	 *
+	 * As Rsense can have tenths of micro-ohm resolution, we need to
+	 * multiply by DECA to get microjoule.
+	 */
+	if (check_mul_overflow(temp * LTC4283_TCONV_uS, energy, &temp_2)) {
+		/*
+		 * We multiply again by 1000 to make sure that we don't get 0
+		 * in the following division which could happen for big rsense
+		 * values. OTOH, we then divide energy first by 1000 so that
+		 * we do not overflow u64 again for very small rsense values.
+		 * We add 100 factor for proper conversion to microjoule.
+		 */
+		temp_2 = DIV64_U64_ROUND_CLOSEST(temp * LTC4283_TCONV_uS * MILLI,
+						 BIT_ULL(24) * st->rsense);
+		energy = DIV_ROUND_CLOSEST_ULL(energy, MILLI * CENTI) * temp_2;
+	} else {
+		/* Put rsense back into nanoohm so we get microjoule. */
+		energy = DIV64_U64_ROUND_CLOSEST(temp_2, BIT_ULL(24) * st->rsense * CENTI);
+	}
+
+	*val = energy;
+	return 0;
+}
+
+static int ltc4283_read(struct device *dev, enum hwmon_sensor_types type,
+			u32 attr, int channel, long *val)
+{
+	struct ltc4283_hwmon *st = dev_get_drvdata(dev);
+
+	switch (type) {
+	case hwmon_in:
+		return ltc4283_read_in(st, attr, channel, val);
+	case hwmon_curr:
+		return ltc4283_read_curr(st, attr, val);
+	case hwmon_power:
+		return ltc4283_read_power(st, attr, val);
+	case hwmon_energy:
+		*val = st->energy_en;
+		return 0;
+	case hwmon_energy64:
+		return ltc4283_read_energy(st, attr, (s64 *)val);
+	default:
+		return -EOPNOTSUPP;
+	}
+}
+
+static int ltc4283_write_power_byte(const struct ltc4283_hwmon *st, u32 reg,
+				    long val)
+{
+	u64 temp = (u64)LTC4283_ADC1_FS_uV * LTC4283_ADC2_FS_mV * DECA * MILLI;
+	u32 __raw;
+
+	val = clamp_val(val, 0, st->power_max);
+	__raw = DIV64_U64_ROUND_CLOSEST(val * BIT_ULL(8) * st->rsense, temp);
+
+	return regmap_write(st->map, reg, __raw);
+}
+
+static int ltc4283_write_power_word(const struct ltc4283_hwmon *st,
+				    u32 reg, long val)
+{
+	u64 temp = st->rsense * BIT_ULL(16), temp_2;
+	u16 __raw;
+
+	if (check_mul_overflow(val, temp, &temp_2)) {
+		temp = DIV_ROUND_CLOSEST_ULL(temp, DECA * MILLI);
+		__raw = DIV_ROUND_CLOSEST_ULL(temp * val, LTC4283_ADC1_FS_uV * LTC4283_ADC2_FS_mV);
+	} else {
+		temp = (u64)LTC4283_ADC1_FS_uV * LTC4283_ADC2_FS_mV * DECA * MILLI;
+		__raw = DIV64_U64_ROUND_CLOSEST(temp_2, temp);
+	}
+
+	return regmap_write(st->map, reg, __raw);
+}
+
+static int ltc4283_reset_power_hist(struct ltc4283_hwmon *st)
+{
+	int ret;
+
+	ret = ltc4283_write_power_word(st, LTC4283_POWER_MIN, st->power_max);
+	if (ret)
+		return ret;
+
+	ret = ltc4283_write_power_word(st, LTC4283_POWER_MAX, 0);
+	if (ret)
+		return ret;
+
+	/* Clear possible power faults. */
+	return regmap_clear_bits(st->map, LTC4283_FAULT_LOG,
+				 LTC4283_PWR_FAIL_FAULT_MASK | LTC4283_PGI_FAULT_MASK);
+}
+
+static int ltc4283_write_power(struct ltc4283_hwmon *st, u32 attr, long val)
+{
+	switch (attr) {
+	case hwmon_power_max:
+		return ltc4283_write_power_byte(st, LTC4283_POWER_MAX_TH, val);
+	case hwmon_power_min:
+		return ltc4283_write_power_byte(st, LTC4283_POWER_MIN_TH, val);
+	case hwmon_power_reset_history:
+		return ltc4283_reset_power_hist(st);
+	default:
+		return -EOPNOTSUPP;
+	}
+}
+
+static int ltc4283_write_in_history(struct ltc4283_hwmon *st, u32 reg,
+				    long lowest, u32 fs)
+{
+	u32 __raw;
+	int ret;
+
+	__raw = DIV_ROUND_CLOSEST(BIT(16) * lowest, fs);
+	if (__raw == BIT(16))
+		__raw = U16_MAX;
+
+	ret = regmap_write(st->map, reg, __raw);
+	if (ret)
+		return ret;
+
+	return regmap_write(st->map, reg + 1, 0);
+}
+
+static int ltc4283_write_in_byte(const struct ltc4283_hwmon *st,
+				 u32 reg, u32 fs, long val)
+{
+	u32 __raw;
+
+	val = clamp_val(val, 0, fs);
+	__raw = DIV_ROUND_CLOSEST(val * BIT(8), fs);
+	if (__raw == BIT(8))
+		__raw = U8_MAX;
+
+	return regmap_write(st->map, reg, __raw);
+}
+
+static int ltc4283_reset_in_hist(struct ltc4283_hwmon *st, u32 channel)
+{
+	u32 reg, fs;
+	int ret;
+
+	/*
+	 * Make sure to clear possible under/over voltage faults. Otherwise the
+	 * chip won't latch on again.
+	 */
+	if (channel == LTC4283_CHAN_VIN)
+		return regmap_clear_bits(st->map, LTC4283_FAULT_LOG,
+					 LTC4283_OV_FAULT_MASK | LTC4283_UV_FAULT_MASK);
+
+	if (channel == LTC4283_CHAN_VPWR)
+		return ltc4283_write_in_history(st, LTC4283_VPWR_MIN,
+						LTC4283_ADC2_FS_mV,
+						LTC4283_ADC2_FS_mV);
+
+	if (channel >= LTC4283_CHAN_ADI_1 && channel <= LTC4283_CHAN_DRAIN) {
+		fs = LTC4283_ADC2_FS_mV;
+		reg = LTC4283_ADC_2_MIN(channel - LTC4283_CHAN_ADI_1);
+	} else {
+		fs = LTC4283_ADC1_FS_uV;
+		reg = LTC4283_ADC_2_MIN_DIFF(channel - LTC4283_CHAN_ADIN12);
+	}
+
+	ret = ltc4283_write_in_history(st, reg, fs, fs);
+	if (ret)
+		return ret;
+	if (channel != LTC4283_CHAN_DRAIN)
+		return 0;
+
+	/* Then, let's also clear possible fet faults. Same as above. */
+	return regmap_clear_bits(st->map, LTC4283_FAULT_LOG,
+				 LTC4283_FET_BAD_FAULT_MASK | LTC4283_FET_SHORT_FAULT_MASK);
+}
+
+static int ltc4283_write_in_en(struct ltc4283_hwmon *st, u32 channel, bool en)
+{
+	unsigned int bit, adc_idx = channel - LTC4283_CHAN_ADI_1;
+	unsigned int reg = LTC4283_ADC_SELECT(adc_idx);
+	int ret;
+
+	bit = LTC4283_ADC_SELECT_MASK(adc_idx);
+	if (channel > LTC4283_CHAN_DRAIN)
+		/* Account for two reserved fields after DRAIN. */
+		bit <<= 2;
+
+	if (en)
+		ret = regmap_set_bits(st->map, reg, bit);
+	else
+		ret = regmap_clear_bits(st->map, reg, bit);
+	if (ret)
+		return ret;
+
+	__assign_bit(channel, &st->ch_enable_mask, en);
+	return 0;
+}
+
+static int ltc4283_write_minmax(struct ltc4283_hwmon *st, long val,
+				u32 channel, bool is_max)
+{
+	u32 reg;
+
+	if (channel == LTC4283_CHAN_VPWR) {
+		if (is_max)
+			return ltc4283_write_in_byte(st, LTC4283_VPWR_MAX_TH,
+						     LTC4283_ADC2_FS_mV, val);
+
+		return ltc4283_write_in_byte(st, LTC4283_VPWR_MIN_TH,
+					     LTC4283_ADC2_FS_mV, val);
+	}
+
+	if (channel >= LTC4283_CHAN_ADI_1 && channel <= LTC4283_CHAN_DRAIN) {
+		if (is_max) {
+			reg = LTC4283_ADC_2_MAX_TH(channel - LTC4283_CHAN_ADI_1);
+			return ltc4283_write_in_byte(st, reg,
+						     LTC4283_ADC2_FS_mV, val);
+		}
+
+		reg = LTC4283_ADC_2_MIN_TH(channel - LTC4283_CHAN_ADI_1);
+		return ltc4283_write_in_byte(st, reg, LTC4283_ADC2_FS_mV, val);
+	}
+
+	/* Just sanity check we do not overflow val for 32bit */
+	val = clamp_val(val * MILLI, 0, LTC4283_ADC1_FS_uV);
+
+	if (is_max) {
+		reg = LTC4283_ADC_2_MAX_TH_DIFF(channel - LTC4283_CHAN_ADIN12);
+		return ltc4283_write_in_byte(st, reg, LTC4283_ADC1_FS_uV, val);
+	}
+
+	reg = LTC4283_ADC_2_MIN_TH_DIFF(channel - LTC4283_CHAN_ADIN12);
+	return ltc4283_write_in_byte(st, reg, LTC4283_ADC1_FS_uV, val);
+}
+
+static int ltc4283_write_in(struct ltc4283_hwmon *st, u32 attr, long val,
+			    int channel)
+{
+	switch (attr) {
+	case hwmon_in_max:
+		return ltc4283_write_minmax(st, val, channel, true);
+	case hwmon_in_min:
+		return ltc4283_write_minmax(st, val, channel, false);
+	case hwmon_in_reset_history:
+		return ltc4283_reset_in_hist(st, channel);
+	case hwmon_in_enable:
+		return ltc4283_write_in_en(st, channel, !!val);
+	default:
+		return -EOPNOTSUPP;
+	}
+}
+
+static int ltc4283_write_curr_byte(const struct ltc4283_hwmon *st,
+				   u32 reg, long val)
+{
+	u32 temp = LTC4283_ADC1_FS_uV * DECA * MILLI;
+	u32 reg_val, isense_max;
+
+	isense_max = DIV_ROUND_CLOSEST(st->vsense_max * MICRO * DECA, st->rsense);
+	val = clamp_val(val, 0, isense_max);
+	reg_val = DIV_ROUND_CLOSEST_ULL(val * BIT_ULL(8) * st->rsense, temp);
+
+	return regmap_write(st->map, reg, reg_val);
+}
+
+static int ltc4283_write_curr_history(struct ltc4283_hwmon *st)
+{
+	int ret;
+
+	ret = ltc4283_write_in_history(st, LTC4283_SENSE_MIN,
+				       st->vsense_max * MILLI,
+				       LTC4283_ADC1_FS_uV);
+	if (ret)
+		return ret;
+
+	/* Now, let's also clear possible overcurrent logs. */
+	return regmap_clear_bits(st->map, LTC4283_FAULT_LOG,
+				 LTC4283_OC_FAULT_MASK);
+}
+
+static int ltc4283_write_curr(struct ltc4283_hwmon *st, u32 attr, long val)
+{
+	switch (attr) {
+	case hwmon_curr_max:
+		return ltc4283_write_curr_byte(st, LTC4283_SENSE_MAX_TH, val);
+	case hwmon_curr_min:
+		return ltc4283_write_curr_byte(st, LTC4283_SENSE_MIN_TH, val);
+	case hwmon_curr_reset_history:
+		return ltc4283_write_curr_history(st);
+	default:
+		return -EOPNOTSUPP;
+	}
+}
+
+static int ltc4283_energy_enable_set(struct ltc4283_hwmon *st, long val)
+{
+	int ret;
+
+	/* Setting the bit halts the meter. */
+	val = !!val;
+	ret = regmap_update_bits(st->map, LTC4283_METER_CONTROL,
+				 LTC4283_METER_HALT_MASK,
+				 FIELD_PREP(LTC4283_METER_HALT_MASK, !val));
+	if (ret)
+		return ret;
+
+	st->energy_en = val;
+
+	return 0;
+}
+
+static int ltc4283_write(struct device *dev, enum hwmon_sensor_types type,
+			 u32 attr, int channel, long val)
+{
+	struct ltc4283_hwmon *st = dev_get_drvdata(dev);
+
+	switch (type) {
+	case hwmon_power:
+		return ltc4283_write_power(st, attr, val);
+	case hwmon_in:
+		return ltc4283_write_in(st, attr, val, channel);
+	case hwmon_curr:
+		return ltc4283_write_curr(st, attr, val);
+	case hwmon_energy:
+		return ltc4283_energy_enable_set(st, val);
+	default:
+		return -EOPNOTSUPP;
+	}
+}
+
+static umode_t ltc4283_in_is_visible(const struct ltc4283_hwmon *st,
+				     u32 attr, int channel)
+{
+	/* If ADIO is set as a GPIO, don´t make it visible. */
+	if (channel >= LTC4283_CHAN_ADIO_1 && channel <= LTC4283_CHAN_ADIO_4) {
+		/* ADIOX pins come at index 0 in the gpio mask. */
+		channel -= LTC4283_CHAN_ADIO_1;
+		if (test_bit(channel, &st->gpio_mask))
+			return 0;
+	}
+
+	/* Also take care of differential channels. */
+	if (channel >= LTC4283_CHAN_ADIO12 && channel <= LTC4283_CHAN_ADIO34) {
+		channel -= LTC4283_CHAN_ADIO12;
+		/* If one channel in the pair is used, make it invisible. */
+		if (test_bit(channel * 2, &st->gpio_mask) ||
+		    test_bit(channel * 2 + 1, &st->gpio_mask))
+			return 0;
+	}
+
+	switch (attr) {
+	case hwmon_in_input:
+	case hwmon_in_highest:
+	case hwmon_in_lowest:
+	case hwmon_in_max_alarm:
+	case hwmon_in_min_alarm:
+	case hwmon_in_label:
+	case hwmon_in_lcrit_alarm:
+	case hwmon_in_crit_alarm:
+	case hwmon_in_fault:
+		return 0444;
+	case hwmon_in_max:
+	case hwmon_in_min:
+	case hwmon_in_enable:
+		return 0644;
+	case hwmon_in_reset_history:
+		return 0200;
+	default:
+		return 0;
+	}
+}
+
+static umode_t ltc4283_curr_is_visible(u32 attr)
+{
+	switch (attr) {
+	case hwmon_curr_input:
+	case hwmon_curr_highest:
+	case hwmon_curr_lowest:
+	case hwmon_curr_max_alarm:
+	case hwmon_curr_min_alarm:
+	case hwmon_curr_crit_alarm:
+	case hwmon_curr_label:
+		return 0444;
+	case hwmon_curr_max:
+	case hwmon_curr_min:
+		return 0644;
+	case hwmon_curr_reset_history:
+		return 0200;
+	default:
+		return 0;
+	}
+}
+
+static umode_t ltc4283_power_is_visible(u32 attr)
+{
+	switch (attr) {
+	case hwmon_power_input:
+	case hwmon_power_input_highest:
+	case hwmon_power_input_lowest:
+	case hwmon_power_label:
+	case hwmon_power_max_alarm:
+	case hwmon_power_min_alarm:
+		return 0444;
+	case hwmon_power_max:
+	case hwmon_power_min:
+		return 0644;
+	case hwmon_power_reset_history:
+		return 0200;
+	default:
+		return 0;
+	}
+}
+
+static umode_t ltc4283_is_visible(const void *data,
+				  enum hwmon_sensor_types type,
+				  u32 attr, int channel)
+{
+	switch (type) {
+	case hwmon_in:
+		return ltc4283_in_is_visible(data, attr, channel);
+	case hwmon_curr:
+		return ltc4283_curr_is_visible(attr);
+	case hwmon_power:
+		return ltc4283_power_is_visible(attr);
+	case hwmon_energy:
+		/* hwmon_energy_enable */
+		return 0644;
+	case hwmon_energy64:
+		/* hwmon_energy_input */
+		return 0444;
+	default:
+		return 0;
+	}
+}
+
+static const char * const ltc4283_in_strs[] = {
+	"VIN", "VPWR", "VADI1", "VADI2", "VADI3", "VADI4", "VADIO1", "VADIO2",
+	"VADIO3", "VADIO4", "DRNS", "DRAIN", "ADIN2-ADIN1", "ADIN4-ADIN3",
+	"ADIO2-ADIO1", "ADIO4-ADIO3"
+};
+
+static int ltc4283_read_labels(struct device *dev,
+			       enum hwmon_sensor_types type,
+			       u32 attr, int channel, const char **str)
+{
+	switch (type) {
+	case hwmon_in:
+		*str = ltc4283_in_strs[channel];
+		return 0;
+	case hwmon_curr:
+		*str = "ISENSE";
+		return 0;
+	case hwmon_power:
+		*str = "Power";
+		return 0;
+	default:
+		return -EOPNOTSUPP;
+	}
+}
+
+/*
+ * Set max limits for ISENSE and Power as that depends on the max voltage on
+ * rsense that is defined in ILIM_ADJUST. This is specially important for power
+ * because for some rsense and vfsout values, if we allow the default raw 255
+ * value, that would overflow long in 32bit archs when reading back the max
+ * power limit.
+ */
+static int ltc4283_set_max_limits(struct ltc4283_hwmon *st, struct device *dev)
+{
+	u32 temp = st->vsense_max * DECA * MICRO;
+	int ret;
+
+	ret = ltc4283_write_in_byte(st, LTC4283_SENSE_MAX_TH, LTC4283_ADC1_FS_uV,
+				    st->vsense_max * MILLI);
+	if (ret)
+		return ret;
+
+	/* Power is given by ISENSE * Vout. */
+	st->power_max = DIV_ROUND_CLOSEST(temp, st->rsense) * LTC4283_ADC2_FS_mV;
+	return ltc4283_write_power_byte(st, LTC4283_POWER_MAX_TH, st->power_max);
+}
+
+static int ltc4283_parse_array_prop(const struct ltc4283_hwmon *st,
+				    struct device *dev, const char *prop,
+				    const u32 *vals, u32 n_vals)
+{
+	u32 prop_val;
+	int ret;
+	u32 i;
+
+	ret = device_property_read_u32(dev, prop, &prop_val);
+	if (ret)
+		return n_vals;
+
+	for (i = 0; i < n_vals; i++) {
+		if (prop_val != vals[i])
+			continue;
+
+		return i;
+	}
+
+	return dev_err_probe(dev, -EINVAL,
+			     "Invalid %s property value %u, expected one of: %*ph\n",
+			     prop, prop_val, n_vals, vals);
+}
+
+static int ltc4283_get_defaults(struct ltc4283_hwmon *st)
+{
+	u32 reg_val, ilm_adjust, c;
+	int ret;
+
+	ret = regmap_read(st->map, LTC4283_METER_CONTROL, &reg_val);
+	if (ret)
+		return ret;
+
+	st->energy_en = !FIELD_GET(LTC4283_METER_HALT_MASK, reg_val);
+
+	ret = regmap_read(st->map, LTC4283_CONFIG_1, &reg_val);
+	if (ret)
+		return ret;
+
+	ilm_adjust = FIELD_GET(LTC4283_ILIM_MASK, reg_val);
+	st->vsense_max = LTC4283_VILIM_MIN_uV / MILLI + ilm_adjust;
+
+	ret = regmap_read(st->map, LTC4283_PGIO_CONFIG, &reg_val);
+	if (ret)
+		return ret;
+
+	/* Can be latter overwritten in ltc4283_pgio_config() */
+	if (FIELD_GET(LTC4283_PGIO4_CFG_MASK, reg_val) < LTC4283_PGIO_FUNC_GPIO)
+		st->ext_fault = true;
+
+	/* VPWR and VIN are always enabled */
+	__set_bit(LTC4283_CHAN_VIN, &st->ch_enable_mask);
+	__set_bit(LTC4283_CHAN_VPWR, &st->ch_enable_mask);
+	for (c = LTC4283_CHAN_ADI_1; c < LTC4283_CHAN_MAX; c++) {
+		u32 chan = c - LTC4283_CHAN_ADI_1, bit;
+
+		ret = regmap_read(st->map, LTC4283_ADC_SELECT(chan), &reg_val);
+		if (ret)
+			return ret;
+
+		bit = LTC4283_ADC_SELECT_MASK(chan);
+		if (c > LTC4283_CHAN_DRAIN)
+			/* account for two reserved fields after DRAIN */
+			bit <<= 2;
+
+		if (!(bit & reg_val))
+			continue;
+
+		__set_bit(c, &st->ch_enable_mask);
+	}
+
+	return 0;
+}
+
+static const char * const ltc4283_pgio1_funcs[] = {
+	"inverted_power_good", "power_good", "gpio"
+};
+
+static const char * const ltc4283_pgio2_funcs[] = {
+	 "inverted_power_good", "power_good", "gpio", "active_current_limiting"
+};
+
+static const char * const ltc4283_pgio3_funcs[] = {
+	"inverted_power_good_input", "power_good_input", "gpio"
+};
+
+static const char * const ltc4283_pgio4_funcs[] = {
+	"inverted_external_fault", "external_fault", "gpio"
+};
+
+enum {
+	LTC4283_PIN_ADIO1,
+	LTC4283_PIN_ADIO2,
+	LTC4283_PIN_ADIO3,
+	LTC4283_PIN_ADIO4,
+	LTC4283_PIN_PGIO1,
+	LTC4283_PIN_PGIO2,
+	LTC4283_PIN_PGIO3,
+	LTC4283_PIN_PGIO4,
+};
+
+static int ltc4283_pgio_config(struct ltc4283_hwmon *st, struct device *dev)
+{
+	int ret, func;
+
+	func = device_property_match_property_string(dev, "adi,pgio1-func",
+						     ltc4283_pgio1_funcs,
+						     ARRAY_SIZE(ltc4283_pgio1_funcs));
+	if (func < 0 && func != -EINVAL)
+		return dev_err_probe(dev, func,
+				     "Invalid adi,pgio1-func property\n");
+	if (func >= 0) {
+		if (func == LTC4283_PGIO_FUNC_GPIO) {
+			__set_bit(LTC4283_PIN_PGIO1, &st->gpio_mask);
+			/* If GPIO, default to an input pin. */
+			func++;
+		}
+
+		ret = regmap_update_bits(st->map, LTC4283_PGIO_CONFIG,
+					 LTC4283_PGIO1_CFG_MASK,
+					 FIELD_PREP(LTC4283_PGIO1_CFG_MASK, func));
+		if (ret)
+			return ret;
+	}
+
+	func = device_property_match_property_string(dev, "adi,pgio2-func",
+						     ltc4283_pgio2_funcs,
+						     ARRAY_SIZE(ltc4283_pgio2_funcs));
+
+	if (func < 0 && func != -EINVAL)
+		return dev_err_probe(dev, func,
+				     "Invalid adi,pgio2-func property\n");
+	if (func >= 0) {
+		if (func != LTC4283_PGIO2_FUNC_ACLB) {
+			if (func == LTC4283_PGIO_FUNC_GPIO)  {
+				__set_bit(LTC4283_PIN_PGIO2, &st->gpio_mask);
+				func++;
+			}
+
+			ret = regmap_update_bits(st->map, LTC4283_PGIO_CONFIG,
+						 LTC4283_PGIO2_CFG_MASK,
+						 FIELD_PREP(LTC4283_PGIO2_CFG_MASK, func));
+		} else {
+			ret = regmap_set_bits(st->map, LTC4283_CONTROL_1,
+					      LTC4283_PIGIO2_ACLB_MASK);
+		}
+
+		if (ret)
+			return ret;
+	}
+
+	func = device_property_match_property_string(dev, "adi,pgio3-func",
+						     ltc4283_pgio3_funcs,
+						     ARRAY_SIZE(ltc4283_pgio3_funcs));
+
+	if (func < 0 && func != -EINVAL)
+		return dev_err_probe(dev, func,
+				     "Invalid adi,pgio3-func property\n");
+	if (func >= 0) {
+		if (func == LTC4283_PGIO_FUNC_GPIO) {
+			__set_bit(LTC4283_PIN_PGIO3, &st->gpio_mask);
+			func++;
+		}
+
+		ret = regmap_update_bits(st->map, LTC4283_PGIO_CONFIG,
+					 LTC4283_PGIO3_CFG_MASK,
+					 FIELD_PREP(LTC4283_PGIO3_CFG_MASK, func));
+		if (ret)
+			return ret;
+	}
+
+	func = device_property_match_property_string(dev, "adi,pgio4-func",
+						     ltc4283_pgio4_funcs,
+						     ARRAY_SIZE(ltc4283_pgio4_funcs));
+
+	if (func < 0 && func != -EINVAL)
+		return dev_err_probe(dev, func,
+				     "Invalid adi,pgio4-func property\n");
+	if (func >= 0) {
+		if (func == LTC4283_PGIO_FUNC_GPIO) {
+			__set_bit(LTC4283_PIN_PGIO4, &st->gpio_mask);
+			func++;
+			st->ext_fault = false;
+		} else {
+			st->ext_fault = true;
+		}
+
+		ret = regmap_update_bits(st->map, LTC4283_PGIO_CONFIG,
+					 LTC4283_PGIO4_CFG_MASK,
+					 FIELD_PREP(LTC4283_PGIO4_CFG_MASK, func));
+		if (ret)
+			return ret;
+	}
+
+	return 0;
+}
+
+static int ltc4283_adio_config(struct ltc4283_hwmon *st, struct device *dev,
+			       const char *prop, u32 pin)
+{
+	u32 adc_idx;
+	int ret;
+
+	if (!device_property_read_bool(dev, prop))
+		return 0;
+
+	adc_idx = LTC4283_CHAN_ADIO_1 - LTC4283_CHAN_ADI_1 + pin;
+	ret = regmap_clear_bits(st->map, LTC4283_ADC_SELECT(adc_idx),
+				LTC4283_ADC_SELECT_MASK(adc_idx));
+	if (ret)
+		return ret;
+
+	__set_bit(pin, &st->gpio_mask);
+	return 0;
+}
+
+static int ltc4283_pin_config(struct ltc4283_hwmon *st, struct device *dev)
+{
+	int ret;
+
+	ret = ltc4283_pgio_config(st, dev);
+	if (ret)
+		return ret;
+
+	ret = ltc4283_adio_config(st, dev, "adi,gpio-on-adio1", LTC4283_PIN_ADIO1);
+	if (ret)
+		return ret;
+
+	ret = ltc4283_adio_config(st, dev, "adi,gpio-on-adio2", LTC4283_PIN_ADIO2);
+	if (ret)
+		return ret;
+
+	ret = ltc4283_adio_config(st, dev, "adi,gpio-on-adio3", LTC4283_PIN_ADIO3);
+	if (ret)
+		return ret;
+
+	return ltc4283_adio_config(st, dev, "adi,gpio-on-adio4", LTC4283_PIN_ADIO4);
+}
+
+static const char * const ltc4283_oc_fet_retry[] = {
+	"latch-off", "1", "7", "unlimited"
+};
+
+static const u32 ltc4283_fb_factor[] = {
+	100, 50, 20, 10
+};
+
+static const u32 ltc4283_cooling_dl[] = {
+	512, 1002, 2005, 4100, 8190, 16400, 32800, 65600
+};
+
+static const u32 ltc4283_fet_bad_delay[] = {
+	256, 512, 1002, 2005
+};
+
+static int ltc4283_setup(struct ltc4283_hwmon *st, struct device *dev)
+{
+	u32 val;
+	int ret;
+
+	/* The part has an eeprom so let's get the needed defaults from it */
+	ret = ltc4283_get_defaults(st);
+	if (ret)
+		return ret;
+
+	/*
+	 * Default to LTC4283_MIN_RSENSE so we can probe without FW properties.
+	 */
+	st->rsense = LTC4283_MIN_RSENSE;
+	ret = device_property_read_u32(dev, "adi,rsense-nano-ohms",
+				       &st->rsense);
+	if (!ret) {
+		if (st->rsense < LTC4283_MIN_RSENSE || st->rsense > LTC4283_MAX_RSENSE)
+			return dev_err_probe(dev, -EINVAL,
+					     "adi,rsense-nano-ohms(%u) too small or too large [%u %u]\n",
+					     st->rsense, LTC4283_MIN_RSENSE, LTC4283_MAX_RSENSE);
+	}
+
+	/*
+	 * The resolution for rsense is tenths of micro (eg: 62.5 uOhm) which
+	 * means we need nano in the bindings. However, to make things easier to
+	 * handle (with respect to overflows) we divide it by 100 as we don't
+	 * really need the last two digits.
+	 */
+	st->rsense /= CENTI;
+
+	ret = device_property_read_u32(dev, "adi,current-limit-sense-microvolt",
+				       &st->vsense_max);
+	if (!ret) {
+		u32 reg_val;
+
+		if (!in_range(st->vsense_max, LTC4283_VILIM_MIN_uV,
+			      LTC4283_VILIM_RANGE)) {
+			return dev_err_probe(dev, -EINVAL,
+					     "adi,current-limit-sense-microvolt (%u) out of range [%u %u]\n",
+					     st->vsense_max, LTC4283_VILIM_MIN_uV,
+					     LTC4283_VILIM_MAX_uV);
+		}
+
+		st->vsense_max /= MILLI;
+		reg_val = FIELD_PREP(LTC4283_ILIM_MASK,
+				     st->vsense_max - LTC4283_VILIM_MIN_uV / MILLI);
+		ret = regmap_update_bits(st->map, LTC4283_CONFIG_1,
+					 LTC4283_ILIM_MASK, reg_val);
+		if (ret)
+			return ret;
+	}
+
+	ret = ltc4283_parse_array_prop(st, dev, "adi,current-limit-foldback-factor",
+				       ltc4283_fb_factor, ARRAY_SIZE(ltc4283_fb_factor));
+	if (ret < 0)
+		return ret;
+	if (ret < ARRAY_SIZE(ltc4283_fb_factor)) {
+		ret = regmap_update_bits(st->map, LTC4283_CONFIG_1, LTC4283_FB_MASK,
+					 FIELD_PREP(LTC4283_FB_MASK, ret));
+		if (ret)
+			return ret;
+	}
+
+	ret = ltc4283_parse_array_prop(st, dev, "adi,cooling-delay-ms",
+				       ltc4283_cooling_dl, ARRAY_SIZE(ltc4283_cooling_dl));
+	if (ret < 0)
+		return ret;
+	if (ret < ARRAY_SIZE(ltc4283_cooling_dl)) {
+		ret = regmap_update_bits(st->map, LTC4283_CONFIG_2, LTC4283_COOLING_DL_MASK,
+					 FIELD_PREP(LTC4283_COOLING_DL_MASK, ret));
+		if (ret)
+			return ret;
+	}
+
+	ret = ltc4283_parse_array_prop(st, dev, "adi,fet-bad-timer-delay-ms",
+				       ltc4283_fet_bad_delay, ARRAY_SIZE(ltc4283_fet_bad_delay));
+	if (ret < 0)
+		return ret;
+	if (ret < ARRAY_SIZE(ltc4283_fet_bad_delay)) {
+		ret = regmap_update_bits(st->map, LTC4283_CONFIG_2, LTC4283_FTBD_DL_MASK,
+					 FIELD_PREP(LTC4283_FTBD_DL_MASK, ret));
+		if (ret)
+			return ret;
+	}
+
+	ret = ltc4283_set_max_limits(st, dev);
+	if (ret)
+		return ret;
+
+	ret = ltc4283_pin_config(st, dev);
+	if (ret)
+		return ret;
+
+	if (device_property_read_bool(dev, "adi,power-good-reset-on-fet")) {
+		ret = regmap_clear_bits(st->map, LTC4283_CONTROL_1,
+					LTC4283_PWRGD_RST_CTRL_MASK);
+		if (ret)
+			return ret;
+	}
+
+	if (device_property_read_bool(dev, "adi,fet-turn-off-disable")) {
+		ret = regmap_clear_bits(st->map, LTC4283_CONTROL_1,
+					LTC4283_FET_BAD_OFF_MASK);
+		if (ret)
+			return ret;
+	}
+
+	if (device_property_read_bool(dev, "adi,tmr-pull-down-disable")) {
+		ret = regmap_set_bits(st->map, LTC4283_CONTROL_1,
+				      LTC4283_THERM_TMR_MASK);
+		if (ret)
+			return ret;
+	}
+
+	if (device_property_read_bool(dev, "adi,dvdt-inrush-control-disable")) {
+		ret = regmap_clear_bits(st->map, LTC4283_CONTROL_1,
+					LTC4283_DVDT_MASK);
+		if (ret)
+			return ret;
+	}
+
+	if (device_property_read_bool(dev, "adi,undervoltage-retry-disable")) {
+		ret = regmap_clear_bits(st->map, LTC4283_CONTROL_2,
+					LTC4283_UV_RETRY_MASK);
+		if (ret)
+			return ret;
+	}
+
+	if (device_property_read_bool(dev, "adi,overvoltage-retry-disable")) {
+		ret = regmap_clear_bits(st->map, LTC4283_CONTROL_2,
+					LTC4283_OV_RETRY_MASK);
+		if (ret)
+			return ret;
+	}
+
+	if (device_property_read_bool(dev, "adi,external-fault-retry-enable")) {
+		if (!st->ext_fault)
+			return dev_err_probe(dev, -EINVAL,
+					     "adi,external-fault-retry-enable set but PGIO4 not configured\n");
+		ret = regmap_set_bits(st->map, LTC4283_CONTROL_2,
+				      LTC4283_EXT_FAULT_RETRY_MASK);
+		if (ret)
+			return ret;
+	}
+
+	if (device_property_read_bool(dev, "adi,fault-log-enable")) {
+		ret = regmap_set_bits(st->map, LTC4283_FAULT_LOG_CTRL,
+				      LTC4283_FAULT_LOG_EN_MASK);
+		if (ret)
+			return ret;
+	}
+
+	ret = device_property_match_property_string(dev, "adi,overcurrent-retries",
+						    ltc4283_oc_fet_retry,
+						    ARRAY_SIZE(ltc4283_oc_fet_retry));
+	/* We still want to catch when an invalid string is given. */
+	if (ret < 0 && ret != -EINVAL)
+		return dev_err_probe(dev, ret,
+				     "adi,overcurrent-retries invalid value\n");
+	if (ret >= 0) {
+		ret = regmap_update_bits(st->map, LTC4283_CONTROL_2,
+					 LTC4283_OC_RETRY_MASK,
+					 FIELD_PREP(LTC4283_OC_RETRY_MASK, ret));
+		if (ret)
+			return ret;
+	}
+
+	ret = device_property_match_property_string(dev, "adi,fet-bad-retries",
+						    ltc4283_oc_fet_retry,
+						    ARRAY_SIZE(ltc4283_oc_fet_retry));
+	if (ret < 0 && ret != -EINVAL)
+		return dev_err_probe(dev, ret,
+				     "adi,fet-bad-retries invalid value\n");
+	if (ret >= 0) {
+		ret = regmap_update_bits(st->map, LTC4283_CONTROL_2,
+					 LTC4283_FET_BAD_RETRY_MASK,
+					 FIELD_PREP(LTC4283_FET_BAD_RETRY_MASK, ret));
+		if (ret)
+			return ret;
+	}
+
+	if (device_property_read_bool(dev, "adi,external-fault-fet-off-enable")) {
+		if (!st->ext_fault)
+			return dev_err_probe(dev, -EINVAL,
+					     "adi,external-fault-fet-off-enable set but PGIO4 not configured\n");
+		ret = regmap_set_bits(st->map, LTC4283_CONFIG_3,
+				      LTC4283_EXTFLT_TURN_OFF_MASK);
+		if (ret)
+			return ret;
+	}
+
+	if (device_property_read_bool(dev, "adi,vpower-drns-enable")) {
+		u32 chan = LTC4283_CHAN_DRNS - LTC4283_CHAN_ADI_1;
+
+		__clear_bit(LTC4283_CHAN_DRNS, &st->ch_enable_mask);
+		/*
+		 * Then, let's by default disable DRNS from ADC2 given that it
+		 * is already being monitored by the VPWR channel. One can still
+		 * enable it later on if needed.
+		 */
+		ret = regmap_clear_bits(st->map, LTC4283_ADC_SELECT(chan),
+					LTC4283_ADC_SELECT_MASK(chan));
+		if (ret)
+			return ret;
+
+		val = 1;
+	} else {
+		val = 0;
+	}
+
+	ret = regmap_update_bits(st->map, LTC4283_CONFIG_3,
+				 LTC4283_VPWR_DRNS_MASK,
+				 FIELD_PREP(LTC4283_VPWR_DRNS_MASK, val));
+	if (ret)
+		return ret;
+
+	/* Make sure the ADC has 12bit resolution since we're assuming that. */
+	ret = regmap_update_bits(st->map, LTC4283_PGIO_CONFIG_2,
+				 LTC4283_ADC_MASK,
+				 FIELD_PREP(LTC4283_ADC_MASK, 3));
+	if (ret)
+		return ret;
+
+	/* Energy reads (which are 6 byte block reads) rely on page access */
+	ret = regmap_set_bits(st->map, LTC4283_CONTROL_1, LTC4283_RW_PAGE_MASK);
+	if (ret)
+		return ret;
+
+	/*
+	 * Make sure we are integrating power as we only support reporting
+	 * consumed energy.
+	 */
+	return regmap_clear_bits(st->map, LTC4283_METER_CONTROL,
+				 LTC4283_INTEGRATE_I_MASK);
+}
+
+static const struct hwmon_channel_info * const ltc4283_info[] = {
+	HWMON_CHANNEL_INFO(in,
+			   HWMON_I_LCRIT_ALARM | HWMON_I_CRIT_ALARM |
+			   HWMON_I_RESET_HISTORY | HWMON_I_LABEL,
+			   HWMON_I_INPUT | HWMON_I_LOWEST | HWMON_I_HIGHEST |
+			   HWMON_I_MAX | HWMON_I_MIN | HWMON_I_MIN_ALARM |
+			   HWMON_I_MAX_ALARM | HWMON_I_RESET_HISTORY |
+			   HWMON_I_LABEL,
+			   HWMON_I_INPUT | HWMON_I_LOWEST | HWMON_I_HIGHEST |
+			   HWMON_I_MAX | HWMON_I_MIN | HWMON_I_MIN_ALARM |
+			   HWMON_I_RESET_HISTORY | HWMON_I_MAX_ALARM |
+			   HWMON_I_ENABLE | HWMON_I_LABEL,
+			   HWMON_I_INPUT | HWMON_I_LOWEST | HWMON_I_HIGHEST |
+			   HWMON_I_MAX | HWMON_I_MIN | HWMON_I_MIN_ALARM |
+			   HWMON_I_RESET_HISTORY | HWMON_I_MAX_ALARM |
+			   HWMON_I_ENABLE | HWMON_I_LABEL,
+			   HWMON_I_INPUT | HWMON_I_LOWEST | HWMON_I_HIGHEST |
+			   HWMON_I_MAX | HWMON_I_MIN | HWMON_I_MIN_ALARM |
+			   HWMON_I_RESET_HISTORY | HWMON_I_MAX_ALARM |
+			   HWMON_I_ENABLE | HWMON_I_LABEL,
+			   HWMON_I_INPUT | HWMON_I_LOWEST | HWMON_I_HIGHEST |
+			   HWMON_I_MAX | HWMON_I_MIN | HWMON_I_MIN_ALARM |
+			   HWMON_I_RESET_HISTORY | HWMON_I_MAX_ALARM |
+			   HWMON_I_ENABLE | HWMON_I_LABEL,
+			   HWMON_I_INPUT | HWMON_I_LOWEST | HWMON_I_HIGHEST |
+			   HWMON_I_MAX | HWMON_I_MIN | HWMON_I_MIN_ALARM |
+			   HWMON_I_RESET_HISTORY | HWMON_I_MAX_ALARM |
+			   HWMON_I_ENABLE | HWMON_I_LABEL,
+			   HWMON_I_INPUT | HWMON_I_LOWEST | HWMON_I_HIGHEST |
+			   HWMON_I_MAX | HWMON_I_MIN | HWMON_I_MIN_ALARM |
+			   HWMON_I_RESET_HISTORY | HWMON_I_MAX_ALARM |
+			   HWMON_I_ENABLE | HWMON_I_LABEL,
+			   HWMON_I_INPUT | HWMON_I_LOWEST | HWMON_I_HIGHEST |
+			   HWMON_I_MAX | HWMON_I_MIN | HWMON_I_MIN_ALARM |
+			   HWMON_I_RESET_HISTORY | HWMON_I_MAX_ALARM |
+			   HWMON_I_ENABLE | HWMON_I_LABEL,
+			   HWMON_I_INPUT | HWMON_I_LOWEST | HWMON_I_HIGHEST |
+			   HWMON_I_MAX | HWMON_I_MIN | HWMON_I_MIN_ALARM |
+			   HWMON_I_RESET_HISTORY | HWMON_I_MAX_ALARM |
+			   HWMON_I_ENABLE | HWMON_I_LABEL,
+			   HWMON_I_INPUT | HWMON_I_LOWEST | HWMON_I_HIGHEST |
+			   HWMON_I_MAX | HWMON_I_MIN | HWMON_I_MIN_ALARM |
+			   HWMON_I_RESET_HISTORY | HWMON_I_MAX_ALARM |
+			   HWMON_I_ENABLE | HWMON_I_LABEL,
+			   HWMON_I_INPUT | HWMON_I_LOWEST | HWMON_I_HIGHEST |
+			   HWMON_I_MAX | HWMON_I_MIN | HWMON_I_MIN_ALARM |
+			   HWMON_I_RESET_HISTORY | HWMON_I_MAX_ALARM |
+			   HWMON_I_FAULT | HWMON_I_ENABLE | HWMON_I_LABEL,
+			   HWMON_I_INPUT | HWMON_I_LOWEST | HWMON_I_HIGHEST |
+			   HWMON_I_MAX | HWMON_I_MIN | HWMON_I_MIN_ALARM |
+			   HWMON_I_RESET_HISTORY | HWMON_I_MAX_ALARM |
+			   HWMON_I_ENABLE | HWMON_I_LABEL,
+			   HWMON_I_INPUT | HWMON_I_LOWEST | HWMON_I_HIGHEST |
+			   HWMON_I_MAX | HWMON_I_MIN | HWMON_I_MIN_ALARM |
+			   HWMON_I_RESET_HISTORY | HWMON_I_MAX_ALARM |
+			   HWMON_I_ENABLE | HWMON_I_LABEL,
+			   HWMON_I_INPUT | HWMON_I_LOWEST | HWMON_I_HIGHEST |
+			   HWMON_I_MAX | HWMON_I_MIN | HWMON_I_MIN_ALARM |
+			   HWMON_I_RESET_HISTORY | HWMON_I_MAX_ALARM |
+			   HWMON_I_ENABLE | HWMON_I_LABEL,
+			   HWMON_I_INPUT | HWMON_I_LOWEST | HWMON_I_HIGHEST |
+			   HWMON_I_MAX | HWMON_I_MIN | HWMON_I_MIN_ALARM |
+			   HWMON_I_RESET_HISTORY | HWMON_I_MAX_ALARM |
+			   HWMON_I_ENABLE | HWMON_I_LABEL),
+	HWMON_CHANNEL_INFO(curr,
+			   HWMON_C_INPUT | HWMON_C_LOWEST | HWMON_C_HIGHEST |
+			   HWMON_C_MAX | HWMON_C_MIN | HWMON_C_MIN_ALARM |
+			   HWMON_C_MAX_ALARM | HWMON_C_CRIT_ALARM |
+			   HWMON_C_RESET_HISTORY | HWMON_C_LABEL),
+	HWMON_CHANNEL_INFO(power,
+			   HWMON_P_INPUT | HWMON_P_INPUT_LOWEST |
+			   HWMON_P_INPUT_HIGHEST | HWMON_P_MAX | HWMON_P_MIN |
+			   HWMON_P_MAX_ALARM | HWMON_P_MIN_ALARM |
+			   HWMON_P_RESET_HISTORY | HWMON_P_LABEL),
+	HWMON_CHANNEL_INFO(energy,
+			   HWMON_E_ENABLE),
+	HWMON_CHANNEL_INFO(energy64,
+			   HWMON_E_INPUT),
+	NULL
+};
+
+static const struct hwmon_ops ltc4283_ops = {
+	.read = ltc4283_read,
+	.write = ltc4283_write,
+	.is_visible = ltc4283_is_visible,
+	.read_string = ltc4283_read_labels,
+};
+
+static const struct hwmon_chip_info ltc4283_chip_info = {
+	.ops = &ltc4283_ops,
+	.info = ltc4283_info,
+};
+
+static int ltc4283_show_fault_log(void *arg, u64 *val, u32 mask)
+{
+	struct ltc4283_hwmon *st = arg;
+	long alarm;
+	int ret;
+
+	ret = ltc4283_read_alarm(st, LTC4283_FAULT_LOG, mask, &alarm);
+	if (ret)
+		return ret;
+
+	*val = alarm;
+
+	return 0;
+}
+
+static int ltc4283_show_in0_lcrit_fault_log(void *arg, u64 *val)
+{
+	return ltc4283_show_fault_log(arg, val, LTC4283_UV_FAULT_MASK);
+}
+DEFINE_DEBUGFS_ATTRIBUTE(ltc4283_in0_lcrit_fault_log,
+			 ltc4283_show_in0_lcrit_fault_log, NULL, "%llu\n");
+
+static int ltc4283_show_in0_crit_fault_log(void *arg, u64 *val)
+{
+	return ltc4283_show_fault_log(arg, val, LTC4283_OV_FAULT_MASK);
+}
+DEFINE_DEBUGFS_ATTRIBUTE(ltc4283_in0_crit_fault_log,
+			 ltc4283_show_in0_crit_fault_log, NULL, "%llu\n");
+
+static int ltc4283_show_fet_bad_fault_log(void *arg, u64 *val)
+{
+	return ltc4283_show_fault_log(arg, val, LTC4283_FET_BAD_FAULT_MASK);
+}
+DEFINE_DEBUGFS_ATTRIBUTE(ltc4283_fet_bad_fault_log,
+			 ltc4283_show_fet_bad_fault_log, NULL, "%llu\n");
+
+static int ltc4283_show_fet_short_fault_log(void *arg, u64 *val)
+{
+	return ltc4283_show_fault_log(arg, val, LTC4283_FET_SHORT_FAULT_MASK);
+}
+DEFINE_DEBUGFS_ATTRIBUTE(ltc4283_fet_short_fault_log,
+			 ltc4283_show_fet_short_fault_log, NULL, "%llu\n");
+
+static int ltc4283_show_curr1_crit_fault_log(void *arg, u64 *val)
+{
+	return ltc4283_show_fault_log(arg, val, LTC4283_OC_FAULT_MASK);
+}
+DEFINE_DEBUGFS_ATTRIBUTE(ltc4283_curr1_crit_fault_log,
+			 ltc4283_show_curr1_crit_fault_log, NULL, "%llu\n");
+
+static int ltc4283_show_power1_failed_fault_log(void *arg, u64 *val)
+{
+	return ltc4283_show_fault_log(arg, val, LTC4283_PWR_FAIL_FAULT_MASK);
+}
+DEFINE_DEBUGFS_ATTRIBUTE(ltc4283_power1_failed_fault_log,
+			 ltc4283_show_power1_failed_fault_log, NULL, "%llu\n");
+
+static int ltc4283_show_power1_good_input_fault_log(void *arg, u64 *val)
+{
+	return ltc4283_show_fault_log(arg, val, LTC4283_PGI_FAULT_MASK);
+}
+DEFINE_DEBUGFS_ATTRIBUTE(ltc4283_power1_good_input_fault_log,
+			 ltc4283_show_power1_good_input_fault_log, NULL, "%llu\n");
+
+static void ltc4283_debugfs_init(struct ltc4283_hwmon *st, struct i2c_client *i2c)
+{
+	debugfs_create_file_unsafe("in0_crit_fault_log", 0400, i2c->debugfs, st,
+				   &ltc4283_in0_crit_fault_log);
+	debugfs_create_file_unsafe("in0_lcrit_fault_log", 0400, i2c->debugfs, st,
+				   &ltc4283_in0_lcrit_fault_log);
+	debugfs_create_file_unsafe("in0_fet_bad_fault_log", 0400, i2c->debugfs, st,
+				   &ltc4283_fet_bad_fault_log);
+	debugfs_create_file_unsafe("in0_fet_short_fault_log", 0400, i2c->debugfs, st,
+				   &ltc4283_fet_short_fault_log);
+	debugfs_create_file_unsafe("curr1_crit_fault_log", 0400, i2c->debugfs, st,
+				   &ltc4283_curr1_crit_fault_log);
+	debugfs_create_file_unsafe("power1_failed_fault_log", 0400, i2c->debugfs, st,
+				   &ltc4283_power1_failed_fault_log);
+	debugfs_create_file_unsafe("power1_good_input_fault_log", 0400, i2c->debugfs,
+				   st, &ltc4283_power1_good_input_fault_log);
+}
+
+static bool ltc4283_is_word_reg(unsigned int reg)
+{
+	return reg >= LTC4283_SENSE && reg <= LTC4283_ADIO34_MAX;
+}
+
+static int ltc4283_reg_read(void *context, unsigned int reg, unsigned int *val)
+{
+	struct i2c_client *client = context;
+	int ret;
+
+	if (ltc4283_is_word_reg(reg))
+		ret = i2c_smbus_read_word_swapped(client, reg);
+	else
+		ret = i2c_smbus_read_byte_data(client, reg);
+
+	if (ret < 0)
+		return ret;
+
+	*val = ret;
+	return 0;
+}
+
+static int ltc4283_reg_write(void *context, unsigned int reg, unsigned int val)
+{
+	struct i2c_client *client = context;
+
+	if (ltc4283_is_word_reg(reg))
+		return i2c_smbus_write_word_swapped(client, reg, val);
+
+	return i2c_smbus_write_byte_data(client, reg, val);
+}
+
+static const struct regmap_bus ltc4283_regmap_bus = {
+	.reg_read = ltc4283_reg_read,
+	.reg_write = ltc4283_reg_write,
+};
+
+static bool ltc4283_writable_reg(struct device *dev, unsigned int reg)
+{
+	switch (reg) {
+	case LTC4283_SYSTEM_STATUS ... LTC4283_FAULT_STATUS:
+		return false;
+	case LTC4283_RESERVED_OC:
+		return false;
+	case LTC4283_RESERVED_86 ... LTC4283_RESERVED_8F:
+		return false;
+	case LTC4283_RESERVED_91 ... LTC4283_RESERVED_A1:
+		return false;
+	case LTC4283_RESERVED_A3:
+		return false;
+	case LTC4283_RESERVED_AC:
+		return false;
+	case LTC4283_POWER_PLAY_MSB ... LTC4283_POWER_PLAY_LSB:
+		return false;
+	case LTC4283_RESERVED_F1 ... LTC4283_RESERVED_FF:
+		return false;
+	default:
+		return true;
+	}
+}
+
+static const struct regmap_config ltc4283_regmap_config = {
+	.reg_bits = 8,
+	.val_bits = 16,
+	.max_register = 0xFF,
+	.writeable_reg = ltc4283_writable_reg,
+};
+
+static int ltc4283_probe(struct i2c_client *client)
+{
+	struct device *dev = &client->dev, *hwmon;
+	struct auxiliary_device *adev;
+	struct ltc4283_hwmon *st;
+	int ret, id;
+
+	st = devm_kzalloc(dev, sizeof(*st), GFP_KERNEL);
+	if (!st)
+		return -ENOMEM;
+
+	if (!i2c_check_functionality(client->adapter,
+				     I2C_FUNC_SMBUS_BYTE_DATA |
+				     I2C_FUNC_SMBUS_WORD_DATA |
+				     I2C_FUNC_SMBUS_READ_I2C_BLOCK))
+		return -EOPNOTSUPP;
+
+	st->client = client;
+	st->map = devm_regmap_init(dev, &ltc4283_regmap_bus, client,
+				   &ltc4283_regmap_config);
+	if (IS_ERR(st->map))
+		return dev_err_probe(dev, PTR_ERR(st->map),
+				     "Failed to create regmap\n");
+
+	ret = ltc4283_setup(st, dev);
+	if (ret)
+		return ret;
+
+	hwmon = devm_hwmon_device_register_with_info(dev, "ltc4283", st,
+						     &ltc4283_chip_info, NULL);
+
+	if (IS_ERR(hwmon))
+		return PTR_ERR(hwmon);
+
+	ltc4283_debugfs_init(st, client);
+
+	if (!st->gpio_mask)
+		return 0;
+
+	id = (client->adapter->nr << 10) | client->addr;
+	adev = __devm_auxiliary_device_create(dev, KBUILD_MODNAME, "gpio",
+					      NULL, id);
+	if (!adev)
+		return dev_err_probe(dev, -ENODEV, "Failed to add GPIO device\n");
+
+	return 0;
+}
+
+static const struct of_device_id ltc4283_of_match[] = {
+	{ .compatible = "adi,ltc4283" },
+	{ }
+};
+
+static const struct i2c_device_id ltc4283_i2c_id[] = {
+	{ "ltc4283" },
+	{ }
+};
+MODULE_DEVICE_TABLE(i2c, ltc4283_i2c_id);
+
+static struct i2c_driver ltc4283_driver = {
+	.driver	= {
+		.name = "ltc4283",
+		.of_match_table = ltc4283_of_match,
+	},
+	.probe = ltc4283_probe,
+	.id_table = ltc4283_i2c_id,
+};
+module_i2c_driver(ltc4283_driver);
+
+MODULE_AUTHOR("Nuno Sá <nuno.sa@analog.com>");
+MODULE_DESCRIPTION("LTC4283 Hot Swap Controller driver");
+MODULE_LICENSE("GPL");

-- 
2.53.0



^ permalink raw reply related

* [PATCH v9 0/3] hwmon: Add support for the LTC4283 Hot Swap Controller
From: Nuno Sá via B4 Relay @ 2026-04-06 14:31 UTC (permalink / raw)
  To: linux-gpio, linux-hwmon, devicetree, linux-doc
  Cc: Guenter Roeck, Rob Herring, Krzysztof Kozlowski, Conor Dooley,
	Jonathan Corbet, Linus Walleij, Bartosz Golaszewski,
	Bartosz Golaszewski

This is v8 for the LTC4283 how swap controller. 

Similar to the LTC4282 device, we're clearing some fault logs in the
reset_history attributes.

Guenter, for my last email worrying about rsense low values, this is
what I got internally:

"10uOhm at the smallest sense voltage of 15mV would be 1500A and 72kW, which
seems a tad excessive. The highest currents I’ve seen are around 200A, and
the -48V market 4283 serves is generally a lot lower than that. Normal values
are around 200uOhm.  I’d say the resolution should be around 1uohm and if a
minimum is needed, 50uOhm is probably safe."

For the resolution, I'm pretty sure I got the tenths of micro
resolution for ltc4282 so I just kept it in here. So, if you don't mind
I would prefer to keep it this way to be safer and changing that now would
require me to change some formulas and I would prefer not to do that at
this stage.

---
Changes in v9:
- Patch 2:
  * Add max and min rsense values to avoid 32bit overflows in power and
    rsense * 256;
  * Fix typo in ltc4283_read_in_alarm() s/LTC4283_CHAN_ADIN34/LTC4283_CHAN_ADIO34;
  * Clamp 'val * MILLI' for LTC4283_ADC1_FS_uV in ltc4283_read_in_alarm();
  * Adapt rsense default and property reading for the new range values.
  * Properly construct an auxdev id from the i2c client.
- Link to v8: https://patch.msgid.link/20260327-ltc4283-support-v8-0-471de255d728@analog.com
---

---
Nuno Sá (3):
      dt-bindings: hwmon: Document the LTC4283 Swap Controller
      hwmon: ltc4283: Add support for the LTC4283 Swap Controller
      gpio: gpio-ltc4283: Add support for the LTC4283 Swap Controller

 .../devicetree/bindings/hwmon/adi,ltc4283.yaml     |  272 +++
 Documentation/hwmon/index.rst                      |    1 +
 Documentation/hwmon/ltc4283.rst                    |  266 +++
 MAINTAINERS                                        |    9 +
 drivers/gpio/Kconfig                               |   15 +
 drivers/gpio/Makefile                              |    1 +
 drivers/gpio/gpio-ltc4283.c                        |  218 +++
 drivers/hwmon/Kconfig                              |   12 +
 drivers/hwmon/Makefile                             |    1 +
 drivers/hwmon/ltc4283.c                            | 1808 ++++++++++++++++++++
 10 files changed, 2603 insertions(+)
---
base-commit: 30a90fa04af6937493fbba20e3e923b5b5a162b4
change-id: 20260303-ltc4283-support-063f78acc5a4
--

Thanks!
- Nuno Sá



^ permalink raw reply

* [PATCH v9 3/3] gpio: gpio-ltc4283: Add support for the LTC4283 Swap Controller
From: Nuno Sá via B4 Relay @ 2026-04-06 14:31 UTC (permalink / raw)
  To: linux-gpio, linux-hwmon, devicetree, linux-doc
  Cc: Guenter Roeck, Rob Herring, Krzysztof Kozlowski, Conor Dooley,
	Jonathan Corbet, Linus Walleij, Bartosz Golaszewski,
	Bartosz Golaszewski
In-Reply-To: <20260406-ltc4283-support-v9-0-b66cfc749261@analog.com>

From: Nuno Sá <nuno.sa@analog.com>

The LTC4283 device has up to 8 pins that can be configured as GPIOs.

Note that PGIO pins are not set as GPIOs by default so if they are
configured to be used as GPIOs we need to make sure to initialize them
to a sane default. They are set as inputs by default.

Acked-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
Reviewed-by: Linus Walleij <linusw@kernel.org>
Signed-off-by: Nuno Sá <nuno.sa@analog.com>
---
 MAINTAINERS                 |   2 +
 drivers/gpio/Kconfig        |  15 +++
 drivers/gpio/Makefile       |   1 +
 drivers/gpio/gpio-ltc4283.c | 218 ++++++++++++++++++++++++++++++++++++++++++++
 4 files changed, 236 insertions(+)

diff --git a/MAINTAINERS b/MAINTAINERS
index a63833b6fe8b..0947cdbac5e5 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -15163,9 +15163,11 @@ F:	drivers/hwmon/ltc4282.c
 
 LTC4283 HARDWARE MONITOR AND GPIO DRIVER
 M:	Nuno Sá <nuno.sa@analog.com>
+L:	linux-gpio@vger.kernel.org
 L:	linux-hwmon@vger.kernel.org
 S:	Supported
 F:	Documentation/devicetree/bindings/hwmon/adi,ltc4283.yaml
+F:	drivers/gpio/gpio-ltc4283.c
 F:	drivers/hwmon/ltc4283.c
 
 LTC4286 HARDWARE MONITOR DRIVER
diff --git a/drivers/gpio/Kconfig b/drivers/gpio/Kconfig
index b45fb799e36c..ba2621024598 100644
--- a/drivers/gpio/Kconfig
+++ b/drivers/gpio/Kconfig
@@ -1758,6 +1758,21 @@ config GPIO_WM8994
 
 endmenu
 
+menu "Auxiliary Bus GPIO drivers"
+	depends on AUXILIARY_BUS
+
+config GPIO_LTC4283
+	tristate "Analog Devices LTC4283 GPIO support"
+	depends on SENSORS_LTC4283
+	help
+	  If you say yes here you want the GPIO function available in Analog
+	  Devices LTC4283 Negative Voltage Hot Swap Controller.
+
+	  This driver can also be built as a module. If so, the module will
+	  be called gpio-ltc4283.
+
+endmenu
+
 menu "PCI GPIO expanders"
 	depends on PCI
 
diff --git a/drivers/gpio/Makefile b/drivers/gpio/Makefile
index c05f7d795c43..ff37aca5029c 100644
--- a/drivers/gpio/Makefile
+++ b/drivers/gpio/Makefile
@@ -102,6 +102,7 @@ obj-$(CONFIG_GPIO_LP873X)		+= gpio-lp873x.o
 obj-$(CONFIG_GPIO_LP87565)		+= gpio-lp87565.o
 obj-$(CONFIG_GPIO_LPC18XX)		+= gpio-lpc18xx.o
 obj-$(CONFIG_GPIO_LPC32XX)		+= gpio-lpc32xx.o
+obj-$(CONFIG_GPIO_LTC4283)		+= gpio-ltc4283.o
 obj-$(CONFIG_GPIO_MACSMC)		+= gpio-macsmc.o
 obj-$(CONFIG_GPIO_MADERA)		+= gpio-madera.o
 obj-$(CONFIG_GPIO_MAX3191X)		+= gpio-max3191x.o
diff --git a/drivers/gpio/gpio-ltc4283.c b/drivers/gpio/gpio-ltc4283.c
new file mode 100644
index 000000000000..6609443c5d62
--- /dev/null
+++ b/drivers/gpio/gpio-ltc4283.c
@@ -0,0 +1,218 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Analog Devices LTC4283 GPIO driver
+ *
+ * Copyright 2025 Analog Devices Inc.
+ */
+
+#include <linux/auxiliary_bus.h>
+#include <linux/bitfield.h>
+#include <linux/bitmap.h>
+#include <linux/bits.h>
+#include <linux/device.h>
+#include <linux/gpio/driver.h>
+#include <linux/mod_devicetable.h>
+#include <linux/module.h>
+#include <linux/regmap.h>
+
+#define LTC4283_PINS_MAX			8
+#define LTC4283_PGIOX_START_NR			4
+#define LTC4283_INPUT_STATUS			0x02
+#define LTC4283_PGIO_CONFIG			0x10
+#define   LTC4283_PGIO_CFG_MASK(pin) \
+	GENMASK(((pin) - LTC4283_PGIOX_START_NR) * 2 + 1, (((pin) - LTC4283_PGIOX_START_NR) * 2))
+#define LTC4283_PGIO_CONFIG_2			0x11
+
+#define LTC4283_ADIO_CONFIG			0x12
+/* starts at bit 4 */
+#define   LTC4283_ADIOX_CONFIG_MASK(pin)	BIT((pin) + 4)
+#define LTC4283_PGIO_DIR_IN			3
+#define LTC4283_PGIO_DIR_OUT			2
+
+struct ltc4283_gpio {
+	struct gpio_chip gpio_chip;
+	struct regmap *regmap;
+};
+
+static int ltc4283_pgio_get_direction(const struct ltc4283_gpio *st, unsigned int off)
+{
+	unsigned int val;
+	int ret;
+
+	ret = regmap_read(st->regmap, LTC4283_PGIO_CONFIG, &val);
+	if (ret)
+		return ret;
+
+	val = field_get(LTC4283_PGIO_CFG_MASK(off), val);
+	if (val == LTC4283_PGIO_DIR_IN)
+		return GPIO_LINE_DIRECTION_IN;
+
+	return GPIO_LINE_DIRECTION_OUT;
+}
+
+static int ltc4283_gpio_get_direction(struct gpio_chip *gc, unsigned int off)
+{
+	struct ltc4283_gpio *st = gpiochip_get_data(gc);
+	unsigned int val;
+	int ret;
+
+	if (off >= LTC4283_PGIOX_START_NR)
+		return ltc4283_pgio_get_direction(st, off);
+
+	ret = regmap_read(st->regmap, LTC4283_ADIO_CONFIG, &val);
+	if (ret)
+		return ret;
+
+	if (val & LTC4283_ADIOX_CONFIG_MASK(off))
+		return GPIO_LINE_DIRECTION_IN;
+
+	return GPIO_LINE_DIRECTION_OUT;
+}
+
+static int ltc4283_gpio_direction_set(const struct ltc4283_gpio *st,
+				      unsigned int off, bool input)
+{
+	if (off >= LTC4283_PGIOX_START_NR) {
+		unsigned int val = LTC4283_PGIO_DIR_OUT;
+
+		if (input)
+			val = LTC4283_PGIO_DIR_IN;
+
+		val = field_prep(LTC4283_PGIO_CFG_MASK(off), val);
+		return regmap_update_bits(st->regmap, LTC4283_PGIO_CONFIG,
+					  LTC4283_PGIO_CFG_MASK(off), val);
+	}
+
+	return regmap_update_bits(st->regmap, LTC4283_ADIO_CONFIG,
+				  LTC4283_ADIOX_CONFIG_MASK(off),
+				  field_prep(LTC4283_ADIOX_CONFIG_MASK(off), input));
+}
+
+static int __ltc4283_gpio_set_value(const struct ltc4283_gpio *st,
+				    unsigned int off, int val)
+{
+	u32 reg = off < LTC4283_PGIOX_START_NR ? LTC4283_ADIO_CONFIG : LTC4283_PGIO_CONFIG_2;
+
+	return regmap_update_bits(st->regmap, reg, BIT(off),
+				  field_prep(BIT(off), !!val));
+}
+
+static int ltc4283_gpio_direction_input(struct gpio_chip *gc, unsigned int off)
+{
+	struct ltc4283_gpio *st = gpiochip_get_data(gc);
+
+	return ltc4283_gpio_direction_set(st, off, true);
+}
+
+static int ltc4283_gpio_direction_output(struct gpio_chip *gc, unsigned int off, int val)
+{
+	struct ltc4283_gpio *st = gpiochip_get_data(gc);
+	int ret;
+
+	ret = ltc4283_gpio_direction_set(st, off, false);
+	if (ret)
+		return ret;
+
+	return __ltc4283_gpio_set_value(st, off, val);
+}
+
+static int ltc4283_gpio_get_value(struct gpio_chip *gc, unsigned int off)
+{
+	struct ltc4283_gpio *st = gpiochip_get_data(gc);
+	unsigned int val, reg;
+	int ret, dir;
+
+	dir = ltc4283_gpio_get_direction(gc, off);
+	if (dir < 0)
+		return dir;
+
+	if (dir == GPIO_LINE_DIRECTION_IN) {
+		ret = regmap_read(st->regmap, LTC4283_INPUT_STATUS, &val);
+		if (ret)
+			return ret;
+
+		/* ADIO1 is at bit 3. */
+		if (off < LTC4283_PGIOX_START_NR)
+			return !!(val & BIT(3 - off));
+
+		/* PGIO1 is at bit 7. */
+		return !!(val & BIT(7 - (off - LTC4283_PGIOX_START_NR)));
+	}
+
+	if (off < LTC4283_PGIOX_START_NR)
+		reg = LTC4283_ADIO_CONFIG;
+	else
+		reg = LTC4283_PGIO_CONFIG_2;
+
+	ret = regmap_read(st->regmap, reg, &val);
+	if (ret)
+		return ret;
+
+	return !!(val & BIT(off));
+}
+
+static int ltc4283_gpio_set_value(struct gpio_chip *gc, unsigned int off, int val)
+{
+	struct ltc4283_gpio *st = gpiochip_get_data(gc);
+
+	return __ltc4283_gpio_set_value(st, off, val);
+}
+
+static int ltc4283_init_valid_mask(struct gpio_chip *gc, unsigned long *valid_mask,
+				   unsigned int ngpios)
+{
+	unsigned long *mask = dev_get_platdata(gc->parent);
+
+	bitmap_copy(valid_mask, mask, ngpios);
+	return 0;
+}
+
+static int ltc4283_gpio_probe(struct auxiliary_device *adev,
+			      const struct auxiliary_device_id *id)
+{
+	struct device *dev = &adev->dev;
+	struct ltc4283_gpio *st;
+	struct gpio_chip *gc;
+
+	st = devm_kzalloc(dev, sizeof(*st), GFP_KERNEL);
+	if (!st)
+		return -ENOMEM;
+
+	st->regmap = dev_get_regmap(dev->parent, NULL);
+	if (!st->regmap)
+		return dev_err_probe(dev, -ENODEV,
+				     "Failed to get regmap\n");
+
+	gc = &st->gpio_chip;
+	gc->parent = dev;
+	gc->get_direction = ltc4283_gpio_get_direction;
+	gc->direction_input = ltc4283_gpio_direction_input;
+	gc->direction_output = ltc4283_gpio_direction_output;
+	gc->get = ltc4283_gpio_get_value;
+	gc->set = ltc4283_gpio_set_value;
+	gc->init_valid_mask = ltc4283_init_valid_mask;
+	gc->can_sleep = true;
+
+	gc->base = -1;
+	gc->ngpio = LTC4283_PINS_MAX;
+	gc->label = adev->name;
+	gc->owner = THIS_MODULE;
+
+	return devm_gpiochip_add_data(dev, &st->gpio_chip, st);
+}
+
+static const struct auxiliary_device_id ltc4283_aux_id_table[] = {
+	{ "ltc4283.gpio" },
+	{ }
+};
+MODULE_DEVICE_TABLE(auxiliary, ltc4283_aux_id_table);
+
+static struct auxiliary_driver ltc4283_gpio_driver = {
+	.probe = ltc4283_gpio_probe,
+	.id_table = ltc4283_aux_id_table,
+};
+module_auxiliary_driver(ltc4283_gpio_driver);
+
+MODULE_AUTHOR("Nuno Sá <nuno.sa@analog.com>");
+MODULE_DESCRIPTION("GPIO LTC4283 Driver");
+MODULE_LICENSE("GPL");

-- 
2.53.0



^ permalink raw reply related

* [PATCH v9 1/3] dt-bindings: hwmon: Document the LTC4283 Swap Controller
From: Nuno Sá via B4 Relay @ 2026-04-06 14:31 UTC (permalink / raw)
  To: linux-gpio, linux-hwmon, devicetree, linux-doc
  Cc: Guenter Roeck, Rob Herring, Krzysztof Kozlowski, Conor Dooley,
	Jonathan Corbet, Linus Walleij, Bartosz Golaszewski
In-Reply-To: <20260406-ltc4283-support-v9-0-b66cfc749261@analog.com>

From: Nuno Sá <nuno.sa@analog.com>

The LTC4283 is a negative voltage hot swap controller that drives an
external N-channel MOSFET to allow a board to be safely inserted and
removed from a live backplane.

Special note for the "adi,vpower-drns-enable" property. It allows to choose
between the attenuated MOSFET drain voltage or the attenuated input
voltage at the RTNS pin (effectively choosing between input or output
power). This is a system level decision not really intended to change at
runtime and hence is being added as a Firmware property.

Reviewed-by: Rob Herring (Arm) <robh@kernel.org>
Signed-off-by: Nuno Sá <nuno.sa@analog.com>
---
 .../devicetree/bindings/hwmon/adi,ltc4283.yaml     | 272 +++++++++++++++++++++
 MAINTAINERS                                        |   6 +
 2 files changed, 278 insertions(+)

diff --git a/Documentation/devicetree/bindings/hwmon/adi,ltc4283.yaml b/Documentation/devicetree/bindings/hwmon/adi,ltc4283.yaml
new file mode 100644
index 000000000000..05e2132ad4d8
--- /dev/null
+++ b/Documentation/devicetree/bindings/hwmon/adi,ltc4283.yaml
@@ -0,0 +1,272 @@
+# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/hwmon/adi,ltc4283.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: LTC4283 Negative Voltage Hot Swap Controller
+
+maintainers:
+  - Nuno Sá <nuno.sa@analog.com>
+
+description: |
+  The LTC4283 negative voltage hot swap controller drives an external N-channel
+  MOSFET to allow a board to be safely inserted and removed from a live
+  backplane.
+
+  https://www.analog.com/media/en/technical-documentation/data-sheets/ltc4283.pdf
+
+properties:
+  compatible:
+    enum:
+      - adi,ltc4283
+
+  reg:
+    maxItems: 1
+
+  adi,rsense-nano-ohms:
+    description: Value of the sense resistor.
+
+  adi,current-limit-sense-microvolt:
+    description:
+      The current limit sense voltage of the chip is adjustable between
+      15mV and 30mV in 1mV steps. This effectively limits the current
+      on the load.
+    minimum: 15000
+    maximum: 30000
+    default: 15000
+
+  adi,current-limit-foldback-factor:
+    description:
+      Specifies the foldback factor for the current limit. The current limit
+      can be reduced (folded back) to one of four preset levels. The value
+      represents the percentage of the current limit sense voltage to use
+      during foldback. A value of 100 means no foldback.
+    $ref: /schemas/types.yaml#/definitions/uint32
+    enum: [10, 20, 50, 100]
+    default: 100
+
+  adi,cooling-delay-ms:
+    description:
+      Cooling time to apply after an overcurrent fault, FET bad or
+      external fault.
+    enum: [512, 1002, 2005, 4100, 8190, 16400, 32800, 65600]
+    default: 512
+
+  adi,fet-bad-timer-delay-ms:
+    description:
+      FET bad timer delay. After a FET bad status condition is detected,
+      this timer is started. If the condition persists for the
+      specified time, the FET is turned off and a fault is logged.
+    enum: [256, 512, 1002, 2005]
+    default: 256
+
+  adi,power-good-reset-on-fet:
+    description:
+      If set, resets the power good status when the MOSFET is turned off.
+      Otherwise, it resets when a low output voltage is detected.
+    type: boolean
+
+  adi,fet-turn-off-disable:
+    description:
+      If set, the MOSFET is not turned off when a FET fault is detected.
+    type: boolean
+
+  adi,tmr-pull-down-disable:
+    description: Disables 2uA pull-down current on the TMR pin.
+    type: boolean
+
+  adi,dvdt-inrush-control-disable:
+    description:
+      Disables dV/dt inrush control during startup. In dV/dt mode, the inrush
+      current is limited by controlling a constant output voltage ramp rate.
+      When disabled, the inrush control mechanism is active current limiting.
+    type: boolean
+
+  adi,fault-log-enable:
+    description:
+      If set, enables logging fault registers and ADC data into EEPROM upon a
+      fault.
+    type: boolean
+
+  adi,vpower-drns-enable:
+    description:
+      If set, enables the attenuated MOSFET drain voltage to be monitored. This
+      effectively means that the MOSFET power is monitored. If not set, the
+      attenuated input voltage (and hence input power) is monitored.
+    type: boolean
+
+  adi,external-fault-fet-off-enable:
+    description: Turns MOSFET off following an external fault.
+    type: boolean
+
+  adi,undervoltage-retry-disable:
+    description: Do not retry to turn on the MOSFET after an undervoltage fault.
+    type: boolean
+
+  adi,overvoltage-retry-disable:
+    description: Do not retry to turn on the MOSFET after an overvoltage fault.
+    type: boolean
+
+  adi,external-fault-retry-enable:
+    description: Retry to turn on the MOSFET after an external fault.
+    type: boolean
+
+  adi,overcurrent-retries:
+    description: Configures auto-retry following an Overcurrent fault.
+    $ref: /schemas/types.yaml#/definitions/string
+    enum: [latch-off, "1", "7", unlimited]
+    default: latch-off
+
+  adi,fet-bad-retries:
+    description:
+      Configures auto-retry following a FET bad fault and a consequent MOSFET
+      turn off.
+    $ref: /schemas/types.yaml#/definitions/string
+    enum: [latch-off, "1", "7", unlimited]
+    default: latch-off
+
+  adi,pgio1-func:
+    description: Configures the function of the PGIO1 pin.
+    $ref: /schemas/types.yaml#/definitions/string
+    enum: [inverted_power_good, power_good, gpio]
+    default: inverted_power_good
+
+  adi,pgio2-func:
+    description: Configures the function of the PGIO2 pin.
+    $ref: /schemas/types.yaml#/definitions/string
+    enum: [inverted_power_good, power_good, gpio, active_current_limiting]
+    default: inverted_power_good
+
+  adi,pgio3-func:
+    description: Configures the function of the PGIO3 pin.
+    $ref: /schemas/types.yaml#/definitions/string
+    enum: [inverted_power_good_input, power_good_input, gpio]
+    default: inverted_power_good_input
+
+  adi,pgio4-func:
+    description: Configures the function of the PGIO4 pin.
+    $ref: /schemas/types.yaml#/definitions/string
+    enum: [inverted_external_fault, external_fault, gpio]
+    default: inverted_external_fault
+
+  adi,gpio-on-adio1:
+    description: If set, the ADIO1 pin is used as a GPIO.
+    type: boolean
+
+  adi,gpio-on-adio2:
+    description: If set, the ADIO2 pin is used as a GPIO.
+    type: boolean
+
+  adi,gpio-on-adio3:
+    description: If set, the ADIO3 pin is used as a GPIO.
+    type: boolean
+
+  adi,gpio-on-adio4:
+    description: If set, the ADIO4 pin is used as a GPIO.
+    type: boolean
+
+  gpio-controller: true
+
+  '#gpio-cells':
+    const: 2
+
+dependencies:
+  adi,gpio-on-adio1:
+    - gpio-controller
+    - '#gpio-cells'
+  adi,gpio-on-adio2:
+    - gpio-controller
+    - '#gpio-cells'
+  adi,gpio-on-adio3:
+    - gpio-controller
+    - '#gpio-cells'
+  adi,gpio-on-adio4:
+    - gpio-controller
+    - '#gpio-cells'
+  adi,external-fault-retry-enable:
+    - adi,pgio4-func
+  adi,external-fault-fet-off-enable:
+    - adi,pgio4-func
+
+required:
+  - compatible
+  - reg
+  - adi,rsense-nano-ohms
+
+allOf:
+  - if:
+      properties:
+        adi,pgio1-func:
+          const: gpio
+      required:
+        - adi,pgio1-func
+    then:
+      required:
+        - gpio-controller
+        - '#gpio-cells'
+
+  - if:
+      properties:
+        adi,pgio2-func:
+          const: gpio
+      required:
+        - adi,pgio2-func
+    then:
+      required:
+        - gpio-controller
+        - '#gpio-cells'
+
+  - if:
+      properties:
+        adi,pgio3-func:
+          const: gpio
+      required:
+        - adi,pgio3-func
+    then:
+      required:
+        - gpio-controller
+        - '#gpio-cells'
+
+  - if:
+      properties:
+        adi,pgio4-func:
+          const: gpio
+      required:
+        - adi,pgio4-func
+    then:
+      properties:
+        adi,external-fault-retry-enable: false
+        adi,external-fault-fet-off-enable: false
+      required:
+        - gpio-controller
+        - '#gpio-cells'
+
+additionalProperties: false
+
+examples:
+  - |
+    i2c {
+        #address-cells = <1>;
+        #size-cells = <0>;
+
+        swap-controller@15 {
+            compatible = "adi,ltc4283";
+            reg = <0x15>;
+
+            adi,rsense-nano-ohms = <500>;
+            adi,current-limit-sense-microvolt = <25000>;
+            adi,current-limit-foldback-factor = <10>;
+            adi,cooling-delay-ms = <8190>;
+            adi,fet-bad-timer-delay-ms = <512>;
+
+            adi,external-fault-fet-off-enable;
+            adi,pgio4-func = "external_fault";
+
+            adi,gpio-on-adio1;
+            adi,pgio1-func = "gpio";
+            gpio-controller;
+            #gpio-cells = <2>;
+        };
+    };
+...
diff --git a/MAINTAINERS b/MAINTAINERS
index e008c2bcc187..3f727d7fdfa4 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -15161,6 +15161,12 @@ F:	Documentation/devicetree/bindings/hwmon/adi,ltc4282.yaml
 F:	Documentation/hwmon/ltc4282.rst
 F:	drivers/hwmon/ltc4282.c
 
+LTC4283 HARDWARE MONITOR AND GPIO DRIVER
+M:	Nuno Sá <nuno.sa@analog.com>
+L:	linux-hwmon@vger.kernel.org
+S:	Supported
+F:	Documentation/devicetree/bindings/hwmon/adi,ltc4283.yaml
+
 LTC4286 HARDWARE MONITOR DRIVER
 M:	Delphine CC Chiu <Delphine_CC_Chiu@Wiwynn.com>
 L:	linux-hwmon@vger.kernel.org

-- 
2.53.0



^ permalink raw reply related

* [PATCH v4 3/4] arm64: dts: hpe: Add HPE GSC SoC and DL340 Gen12 board DTS
From: nick.hawkins @ 2026-04-06 14:38 UTC (permalink / raw)
  To: catalin.marinas, will, robh, krzk+dt, conor+dt
  Cc: nick.hawkins, linux-arm-kernel, devicetree, linux-kernel
In-Reply-To: <20260406143821.1843621-1-nick.hawkins@hpe.com>

From: Nick Hawkins <nick.hawkins@hpe.com>

From: Nick Hawkins <nick.hawkins@hpe.com>

Add SoC-level DTSI for the HPE GSC ARM64 BMC SoC, covering the CPU
cluster, GIC v3 interrupt controller, ARM64 generic timer, and console
UART.

Add the board-level DTS for the HPE DL340 Gen12, which includes
gsc.dtsi and adds memory and chosen nodes.

Signed-off-by: Nick Hawkins <nick.hawkins@hpe.com>
---
 arch/arm64/boot/dts/hpe/Makefile           |   2 +
 arch/arm64/boot/dts/hpe/gsc-dl340gen12.dts |  18 ++++
 arch/arm64/boot/dts/hpe/gsc.dtsi           | 104 +++++++++++++++++++++
 3 files changed, 124 insertions(+)
 create mode 100644 arch/arm64/boot/dts/hpe/Makefile
 create mode 100644 arch/arm64/boot/dts/hpe/gsc-dl340gen12.dts
 create mode 100644 arch/arm64/boot/dts/hpe/gsc.dtsi

diff --git a/arch/arm64/boot/dts/hpe/Makefile b/arch/arm64/boot/dts/hpe/Makefile
new file mode 100644
index 000000000000..6b547b8a8154
--- /dev/null
+++ b/arch/arm64/boot/dts/hpe/Makefile
@@ -0,0 +1,2 @@
+# SPDX-License-Identifier: GPL-2.0-only
+dtb-$(CONFIG_ARCH_HPE) += gsc-dl340gen12.dtb
diff --git a/arch/arm64/boot/dts/hpe/gsc-dl340gen12.dts b/arch/arm64/boot/dts/hpe/gsc-dl340gen12.dts
new file mode 100644
index 000000000000..7a3d9f1c4b2e
--- /dev/null
+++ b/arch/arm64/boot/dts/hpe/gsc-dl340gen12.dts
@@ -0,0 +1,18 @@
+// SPDX-License-Identifier: GPL-2.0
+/dts-v1/;
+
+#include "gsc.dtsi"
+
+/ {
+	compatible = "hpe,gsc-dl340gen12", "hpe,gsc";
+	model = "HPE ProLiant DL340 Gen12";
+
+	chosen {
+		stdout-path = &uartc;
+	};
+
+	memory@0 {
+		device_type = "memory";
+		reg = <0x00000000 0x40000000>;
+	};
+};
diff --git a/arch/arm64/boot/dts/hpe/gsc.dtsi b/arch/arm64/boot/dts/hpe/gsc.dtsi
new file mode 100644
index 000000000000..1f4c2a7b3d91
--- /dev/null
+++ b/arch/arm64/boot/dts/hpe/gsc.dtsi
@@ -0,0 +1,104 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Device Tree file for HPE GSC
+ */
+
+#include <dt-bindings/interrupt-controller/arm-gic.h>
+
+/ {
+	#address-cells = <1>;
+	#size-cells = <1>;
+
+	osc: clock-33333333 {
+		compatible = "fixed-clock";
+		#clock-cells = <0>;
+		clock-output-names = "osc";
+		clock-frequency = <33333333>;
+	};
+
+	cpus {
+		#address-cells = <1>;
+		#size-cells = <0>;
+
+		cpu@0 {
+			device_type = "cpu";
+			compatible = "arm,cortex-a53";
+			reg = <0>;
+			enable-method = "spin-table";
+			cpu-release-addr = <0 0xa0008048>;
+		};
+
+		cpu@1 {
+			device_type = "cpu";
+			compatible = "arm,cortex-a53";
+			reg = <1>;
+			enable-method = "spin-table";
+			cpu-release-addr = <0 0xa0008048>;
+		};
+	};
+
+	timer {
+		compatible = "arm,armv8-timer";
+		interrupt-parent = <&gic>;
+		interrupts = <GIC_PPI 13 IRQ_TYPE_LEVEL_LOW>,
+			     <GIC_PPI 14 IRQ_TYPE_LEVEL_LOW>,
+			     <GIC_PPI 11 IRQ_TYPE_LEVEL_LOW>,
+			     <GIC_PPI 10 IRQ_TYPE_LEVEL_LOW>;
+	};
+
+	soc: soc@80000000 {
+		compatible = "simple-bus";
+		reg = <0x80000000 0x80000000>;
+		#address-cells = <1>;
+		#size-cells = <1>;
+		ranges;
+
+		uarta: serial@c00000e0 {
+			compatible = "ns16550a";
+			reg = <0xc00000e0 0x8>;
+			clock-frequency = <1846153>;
+			interrupt-parent = <&gic>;
+			interrupts = <GIC_SPI 17 IRQ_TYPE_LEVEL_HIGH>;
+			reg-shift = <0>;
+		};
+
+		uartb: serial@c00000e8 {
+			compatible = "ns16550a";
+			reg = <0xc00000e8 0x8>;
+			clock-frequency = <1846153>;
+			interrupt-parent = <&gic>;
+			interrupts = <GIC_SPI 18 IRQ_TYPE_LEVEL_HIGH>;
+			reg-shift = <0>;
+		};
+
+		uartc: serial@c00000f0 {
+			compatible = "ns16550a";
+			reg = <0xc00000f0 0x8>;
+			clock-frequency = <1846153>;
+			interrupt-parent = <&gic>;
+			interrupts = <GIC_SPI 19 IRQ_TYPE_LEVEL_HIGH>;
+			reg-shift = <0>;
+		};
+
+		uarte: serial@c00003e0 {
+			compatible = "ns16550a";
+			reg = <0xc00003e0 0x8>;
+			clock-frequency = <1846153>;
+			interrupt-parent = <&gic>;
+			interrupts = <GIC_SPI 12 IRQ_TYPE_LEVEL_HIGH>;
+			reg-shift = <0>;
+		};
+
+		gic: gic@ce000000 {
+			compatible = "arm,gic-v3";
+			reg = <0xce000000 0x10000>,
+			      <0xce060000 0x40000>,
+			      <0xce200000 0x40000>;
+			#address-cells = <0>;
+			#interrupt-cells = <3>;
+			#redistributor-regions = <1>;
+			interrupt-controller;
+			redistributor-stride = <0x0 0x20000>;
+		};
+	};
+};
-- 
2.34.1

^ permalink raw reply related

* [PATCH v4 2/4] arm64: Kconfig: Add ARCH_HPE platform
From: nick.hawkins @ 2026-04-06 14:38 UTC (permalink / raw)
  To: catalin.marinas, will, robh, krzk+dt, conor+dt
  Cc: nick.hawkins, linux-arm-kernel, devicetree, linux-kernel,
	Krzysztof Kozlowski
In-Reply-To: <20260406143821.1843621-1-nick.hawkins@hpe.com>

From: Nick Hawkins <nick.hawkins@hpe.com>

From: Nick Hawkins <nick.hawkins@hpe.com>

Add the ARCH_HPE config for HPE ARM64 BMC SoCs to Kconfig.platforms.

Signed-off-by: Nick Hawkins <nick.hawkins@hpe.com>
Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@oss.qualcomm.com>
---
 arch/arm64/Kconfig.platforms | 11 +++++++++++
 1 file changed, 11 insertions(+)

diff --git a/arch/arm64/Kconfig.platforms b/arch/arm64/Kconfig.platforms
index 54eb1d7fd419..b4217809c774 100644
--- a/arch/arm64/Kconfig.platforms
+++ b/arch/arm64/Kconfig.platforms
@@ -168,6 +168,17 @@ config ARCH_HISI
 	help
 	  This enables support for Hisilicon ARMv8 SoC family
 
+config ARCH_HPE
+	bool "HPE SoC Support"
+	select PINCTRL
+	select GENERIC_IRQ_CHIP
+	select CLKSRC_MMIO
+	help
+	  This enables support for HPE ARM-based SoC chips used
+	  on HPE servers. HPE SoCs serve as the Baseboard
+	  Management Controller (BMC) providing out-of-band server
+	  management.
+
 config ARCH_KEEMBAY
 	bool "Keem Bay SoC"
 	help
-- 
2.34.1

^ permalink raw reply related

* [PATCH v4 4/4] arm64: defconfig: Enable ARCH_HPE
From: nick.hawkins @ 2026-04-06 14:38 UTC (permalink / raw)
  To: catalin.marinas, will, robh, krzk+dt, conor+dt
  Cc: nick.hawkins, linux-arm-kernel, devicetree, linux-kernel
In-Reply-To: <20260406143821.1843621-1-nick.hawkins@hpe.com>

From: Nick Hawkins <nick.hawkins@hpe.com>

From: Nick Hawkins <nick.hawkins@hpe.com>

Enable ARCH_HPE in the arm64 defconfig to include HPE GSC BMC SoC
support in the default build.

Signed-off-by: Nick Hawkins <nick.hawkins@hpe.com>
---
 arch/arm64/configs/defconfig | 1 +
 1 file changed, 1 insertion(+)

diff --git a/arch/arm64/configs/defconfig b/arch/arm64/configs/defconfig
index xxxxxxxxxxxxxxx..xxxxxxxxxxxxxxx 100644
--- a/arch/arm64/configs/defconfig
+++ b/arch/arm64/configs/defconfig
@@ -xx,6 +xx,7 @@
 CONFIG_ARCH_HISI=y
+CONFIG_ARCH_HPE=y
 CONFIG_ARCH_KEEMBAY=y
-- 
2.34.1

^ permalink raw reply

* [PATCH v4 1/4] dt-bindings: arm: hpe,gxp: Add HPE GSC platform compatible
From: nick.hawkins @ 2026-04-06 14:38 UTC (permalink / raw)
  To: catalin.marinas, will, robh, krzk+dt, conor+dt
  Cc: nick.hawkins, linux-arm-kernel, devicetree, linux-kernel
In-Reply-To: <20260406143821.1843621-1-nick.hawkins@hpe.com>

From: Nick Hawkins <nick.hawkins@hpe.com>

From: Nick Hawkins <nick.hawkins@hpe.com>

Add the HPE GSC ARM64 BMC SoC compatibles to the existing
hpe,gxp.yaml binding.

The initial board compatible is hpe,gsc-dl340gen12 for the DL340 Gen12
server platform.

Add the arm64 DTS path to the existing ARM/HPE GXP MAINTAINERS entry,
renamed to ARM/HPE GXP/GSC ARCHITECTURE.

Signed-off-by: Nick Hawkins <nick.hawkins@hpe.com>
---
 Documentation/devicetree/bindings/arm/hpe,gxp.yaml | 7 ++++++-
 MAINTAINERS                                        | 3 ++-
 2 files changed, 8 insertions(+), 2 deletions(-)

diff --git a/Documentation/devicetree/bindings/arm/hpe,gxp.yaml b/Documentation/devicetree/bindings/arm/hpe,gxp.yaml
index 224bbcb93f95..6f057cd58571 100644
--- a/Documentation/devicetree/bindings/arm/hpe,gxp.yaml
+++ b/Documentation/devicetree/bindings/arm/hpe,gxp.yaml
@@ -4,7 +4,7 @@
 $id: http://devicetree.org/schemas/arm/hpe,gxp.yaml#
 $schema: http://devicetree.org/meta-schemas/core.yaml#
 
-title: HPE BMC GXP platforms
+title: HPE BMC GXP and GSC platforms
 
 maintainers:
   - Nick Hawkins <nick.hawkins@hpe.com>
 @@ -15,6 +15,11 @@ properties:
     oneOf:
+      - description: GSC Based Boards
+        items:
+          - enum:
+              - hpe,gsc-dl340gen12
+          - const: hpe,gsc
       - description: GXP Based Boards
         items:
           - enum:
               - hpe,gxp-dl360gen10
           - const: hpe,gxp
 
 required:
   - compatible
diff --git a/MAINTAINERS b/MAINTAINERS
index 2265e2c9bfbe..80c66de5e342 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -2859,7 +2859,7 @@ T:	git git://git.kernel.org/pub/scm/linux/kernel/git/kristoffer/linux-hpc.git
 F:	arch/arm/mach-sa1100/include/mach/jornada720.h
 F:	arch/arm/mach-sa1100/jornada720.c
 
-ARM/HPE GXP ARCHITECTURE
+ARM/HPE GXP/GSC ARCHITECTURE
 M:	Jean-Marie Verdun <verdun@hpe.com>
 M:	Nick Hawkins <nick.hawkins@hpe.com>
 S:	Maintained
@@ -2870,6 +2870,7 @@ F:	Documentation/devicetree/bindings/spi/hpe,gxp-spifi.yaml
 F:	Documentation/devicetree/bindings/timer/hpe,gxp-timer.yaml
 F:	Documentation/hwmon/gxp-fan-ctrl.rst
 F:	arch/arm/boot/dts/hpe/
+F:	arch/arm64/boot/dts/hpe/
 F:	drivers/clocksource/timer-gxp.c
 F:	drivers/hwmon/gxp-fan-ctrl.c
 F:	drivers/i2c/busses/i2c-gxp.c
-- 
2.34.1

^ permalink raw reply related

* [PATCH v4 0/4] arm64: Add HPE GSC platform support
From: nick.hawkins @ 2026-04-06 14:38 UTC (permalink / raw)
  To: catalin.marinas, will, robh, krzk+dt, conor+dt
  Cc: nick.hawkins, linux-arm-kernel, devicetree, linux-kernel

From: Nick Hawkins <nick.hawkins@hpe.com>

From: Nick Hawkins <nick.hawkins@hpe.com>

Add initial platform support for the HPE GSC ARM64 BMC SoC.

Changes since v3:
- Patch 1: Moved GSC entry before GXP in hpe,gxp.yaml to maintain
  alphabetical ordering by fallback compatible (Krzysztof Kozlowski)
- Patch 2: Added Reviewed-by from Krzysztof Kozlowski
- Patch 3: Changed SPDX in gsc-dl340gen12.dts from GPL-2.0-only to
  GPL-2.0 to be consistent with gsc.dtsi (Krzysztof Kozlowski);
  reordered nodes within soc by ascending unit-address, placing UARTs
  before GIC per DTS coding style (Krzysztof Kozlowski);
  moved interrupt-parent before interrupts in timer and all UART nodes
  per DTS coding style (Krzysztof Kozlowski);
  reordered root-level nodes alphabetically: clock-33333333 before cpus
  before timer per DTS coding style (Krzysztof Kozlowski);
  reordered properties within all nodes to follow DTS coding style:
  compatible, reg first, then remaining alphabetically (Krzysztof
  Kozlowski)
- Patch 4: New patch adding CONFIG_ARCH_HPE=y to arm64 defconfig
  (Krzysztof Kozlowski)

Nick Hawkins (4):
  dt-bindings: arm: hpe,gxp: Add HPE GSC platform compatible
  arm64: Kconfig: Add ARCH_HPE platform
  arm64: dts: hpe: Add HPE GSC SoC and DL340 Gen12 board DTS
  arm64: defconfig: Enable ARCH_HPE

 .../devicetree/bindings/arm/hpe,gxp.yaml      |   7 +-
 MAINTAINERS                                   |   3 +-
 arch/arm64/Kconfig.platforms                  |  11 ++
 arch/arm64/boot/dts/hpe/Makefile              |   2 +
 arch/arm64/boot/dts/hpe/gsc-dl340gen12.dts    |  18 +++
 arch/arm64/boot/dts/hpe/gsc.dtsi              | 104 ++++++++++++++++++
 arch/arm64/configs/defconfig                  |   1 +
 7 files changed, 144 insertions(+), 2 deletions(-)
 create mode 100644 arch/arm64/boot/dts/hpe/Makefile
 create mode 100644 arch/arm64/boot/dts/hpe/gsc-dl340gen12.dts
 create mode 100644 arch/arm64/boot/dts/hpe/gsc.dtsi

-- 
2.34.1

^ permalink raw reply


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