* [PATCH 1/2] dt-bindings: arm: qcom: Add SM7325 Motorola edge 30 (dubai)
From: Val Packett @ 2026-03-29 10:16 UTC (permalink / raw)
To: Bjorn Andersson, Konrad Dybcio, Rob Herring, Krzysztof Kozlowski,
Conor Dooley
Cc: Val Packett, linux-arm-msm, devicetree, linux-kernel
Motorola edge 30 (motorola,dubai) is a smartphone based on the
SM7325 SoC.
Signed-off-by: Val Packett <val@packett.cool>
---
Documentation/devicetree/bindings/arm/qcom.yaml | 1 +
1 file changed, 1 insertion(+)
diff --git a/Documentation/devicetree/bindings/arm/qcom.yaml b/Documentation/devicetree/bindings/arm/qcom.yaml
index ca880c105f3b..58f1621bb855 100644
--- a/Documentation/devicetree/bindings/arm/qcom.yaml
+++ b/Documentation/devicetree/bindings/arm/qcom.yaml
@@ -1038,6 +1038,7 @@ properties:
- items:
- enum:
+ - motorola,dubai
- nothing,spacewar
- const: qcom,sm7325
--
2.53.0
^ permalink raw reply related
* Re: [PATCH v8 1/6] dt-bindings: pinctrl: add NXP MC33978/MC34978 MSDI
From: Rob Herring (Arm) @ 2026-03-29 10:30 UTC (permalink / raw)
To: Oleksij Rempel
Cc: Linus Walleij, linux-kernel, kernel, Lee Jones, devicetree,
David Jander, Krzysztof Kozlowski, linux-hwmon, linux-gpio,
Guenter Roeck, Peter Rosin, Conor Dooley
In-Reply-To: <20260329090601.532477-2-o.rempel@pengutronix.de>
On Sun, 29 Mar 2026 11:05:56 +0200, Oleksij Rempel wrote:
> Add device tree binding documentation for the NXP MC33978 and MC34978
> Multiple Switch Detection Interface (MSDI) devices.
>
> The MC33978 and MC34978 differ primarily in their operating temperature
> ranges. While not software-detectable, providing specific compatible
> strings allows the hwmon subsystem to correctly interpret thermal
> thresholds and hardware faults.
>
> These ICs monitor up to 22 mechanical switch contacts in automotive and
> industrial environments. They provide configurable wetting currents to
> break through contact oxidation and feature extensive hardware
> protection against thermal overload and voltage transients (load
> dumps/brown-outs).
>
> The device interfaces via SPI. While it provides multiple functions, its
> primary hardware purpose is pin/switch control. To accurately represent
> the hardware as a single physical integrated circuit without unnecessary
> DT overhead, all functions are flattened into a single pinctrl node:
> - pinctrl: Exposing the 22 switch inputs (SG/SP pins) as a GPIO controller
> and managing their pin configurations.
> - hwmon: Exposing critical hardware faults (OT, OV, UV) and static
> voltage/temperature thresholds.
> - mux: Controlling the 24-to-1 analog multiplexer to route pin voltages,
> internal temperature, or battery voltage to an external SoC ADC.
>
> Signed-off-by: Oleksij Rempel <o.rempel@pengutronix.de>
> Reviewed-by: Rob Herring (Arm) <robh@kernel.org>
> Reviewed-by: Linus Walleij <linusw@kernel.org>
> ---
> changes v8:
> - Update IRQ_TYPE_* macros include path reference in documentation from
> interrupt-controller.h to dt-bindings/interrupt-controller/irq.h.
> - Add bias-disable, drive-open-drain, drive-open-source, and drive-strength
> to the list of supported pin configuration properties.
> changes v7:
> - no changes
> changes v6:
> - add Reviewed-by: Rob Herring (Arm) <robh@kernel.org>
> - add Reviewed-by: Linus Walleij <linusw@kernel.org>
> changes v5:
> - Commit Message: Added justification for distinct compatible strings
> based on temperature ranges.
> - Restricted pins property to an explicit enum of valid hardware pins
> changes v4:
> - Drop the standalone mfd/nxp,mc33978.yaml schema entirely.
> - Move the unified device binding to bindings/pinctrl/nxp,mc33978.yaml,
> - Remove the dedicated child node compatible strings (nxp,mc33978-pinctrl).
> - Flatten the pinctrl/gpio properties directly into the main SPI device
> node.
> changes v3:
> - Drop regular expression pattern from pinctrl child node and define
> it as a standard property
> - Reorder required properties list in MFD binding
> - Remove stray blank line from the MFD binding devicetree example
> - Replace unevaluatedProperties with additionalProperties in the pinctrl
> binding
> changes v2:
> - Squashed MFD, pinctrl, hwmon, and mux bindings into a single patch
> - Removed the empty hwmon child node
> - Folded the mux-controller node into the parent MFD node
> - Added vbatp-supply and vddq-supply to the required properties block
> - Changed the example node name from mc33978@0 to gpio@0
> - Removed unnecessary literal block scalars (|) from descriptions
> - Documented SG, SP, and SB pin acronyms in the pinctrl description
> - Added consumer polarity guidance (GPIO_ACTIVE_LOW/HIGH) for SG/SB
> inputs, with a note on output circuit dependency
> - Updated commit message
> ---
> .../bindings/pinctrl/nxp,mc33978.yaml | 158 ++++++++++++++++++
> 1 file changed, 158 insertions(+)
> create mode 100644 Documentation/devicetree/bindings/pinctrl/nxp,mc33978.yaml
>
My bot found errors running 'make dt_binding_check' on your patch:
yamllint warnings/errors:
dtschema/dtc warnings/errors:
/builds/robherring/dt-review-ci/linux/Documentation/devicetree/bindings/pinctrl/nxp,mc33978.example.dtb: gpio@0 (nxp,mc33978): $nodename:0: 'gpio@0' does not match '^mux-controller(@.*|-([0-9]|[1-9][0-9]+))?$'
from schema $id: http://devicetree.org/schemas/mux/mux-controller.yaml
doc reference errors (make refcheckdocs):
See https://patchwork.kernel.org/project/devicetree/patch/20260329090601.532477-2-o.rempel@pengutronix.de
The base for the series is generally the latest rc1. A different dependency
should be noted in *this* patch.
If you already ran 'make dt_binding_check' and didn't see the above
error(s), then make sure 'yamllint' is installed and dt-schema is up to
date:
pip3 install dtschema --upgrade
Please check and re-submit after running the above command yourself. Note
that DT_SCHEMA_FILES can be set to your schema file to speed up checking
your schema. However, it must be unset to test all examples with your schema.
^ permalink raw reply
* Re: [PATCH 2/2] arm64: dts: qcom: drop redundant zap-shader memory-region
From: Dmitry Baryshkov @ 2026-03-29 10:23 UTC (permalink / raw)
To: Tobias Heider
Cc: Bjorn Andersson, Konrad Dybcio, Rob Herring, Krzysztof Kozlowski,
Conor Dooley, linux-arm-msm, devicetree, linux-kernel
In-Reply-To: <20260328-zap-v1-2-f6810b9b4930@canonical.com>
On Sat, Mar 28, 2026 at 04:49:22PM +0100, Tobias Heider wrote:
> This is already defined in the gpu_zap_shader node in hamoa.dtsi,
> there is no need to redefine it.
>
> Signed-off-by: Tobias Heider <tobias.heider@canonical.com>
> ---
> arch/arm64/boot/dts/qcom/x1-microsoft-denali.dtsi | 1 -
> arch/arm64/boot/dts/qcom/x1e80100-microsoft-romulus.dtsi | 1 -
> 2 files changed, 2 deletions(-)
>
> diff --git a/arch/arm64/boot/dts/qcom/x1-microsoft-denali.dtsi b/arch/arm64/boot/dts/qcom/x1-microsoft-denali.dtsi
Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@oss.qualcomm.com>
--
With best wishes
Dmitry
^ permalink raw reply
* Re: [PATCH 1/2] arm64: dts: qcom: fix remaining gpu_zap_shader labels
From: Dmitry Baryshkov @ 2026-03-29 10:22 UTC (permalink / raw)
To: Tobias Heider
Cc: Bjorn Andersson, Konrad Dybcio, Rob Herring, Krzysztof Kozlowski,
Conor Dooley, linux-arm-msm, devicetree, linux-kernel
In-Reply-To: <20260328-zap-v1-1-f6810b9b4930@canonical.com>
On Sat, Mar 28, 2026 at 04:49:21PM +0100, Tobias Heider wrote:
> Most qcom DTs were converted to use the gpu_zap_shader label instead
> of patching the gpu node in commit 2377626fd216 ("arm64: dts: qcom:
> add gpu_zap_shader label"). This fixes the remaining ones.
>
> Signed-off-by: Tobias Heider <tobias.heider@canonical.com>
> ---
> arch/arm64/boot/dts/qcom/x1-microsoft-denali.dtsi | 8 ++++----
> arch/arm64/boot/dts/qcom/x1e80100-medion-sprchrgd-14-s1.dts | 6 +++---
> 2 files changed, 7 insertions(+), 7 deletions(-)
>
Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@oss.qualcomm.com>
--
With best wishes
Dmitry
^ permalink raw reply
* Re: [PATCH net-next v2] dt-bindings: net: wireless: brcm: Add compatible for bcm43752
From: Arend van Spriel @ 2026-03-29 10:21 UTC (permalink / raw)
To: Ronald Claveau, Johannes Berg, Rob Herring, Krzysztof Kozlowski,
Conor Dooley, van Spriel
Cc: linux-wireless, devicetree, linux-kernel, netdev, Conor Dooley
In-Reply-To: <20260327-add-bcm43752-compatible-v2-1-5b28e6637101@aliel.fr>
On 27/03/2026 10:36, Ronald Claveau wrote:
> Add bcm43752 compatible with its bcm4329 compatible fallback.
Hi Johannes,
I moved this patch to you in patchwork. In response by Neil Armstrong to
earlier proposed patch it seems he prefers this to go through the
wireless or networking tree.
Regards,
Arend
> Acked-by: Conor Dooley <conor.dooley@microchip.com>
> Signed-off-by: Ronald Claveau <linux-kernel-dev@aliel.fr>
> ---
> The Khadas VIM4 board based on Amlogic A311D2 aka T7 features an AP6275s Wi-Fi/Bluetooth module with a BCM43752 chipset.
> This patch aims to add this chipset with its fallback to bcm4329 compatible.
>
> The original patch series is here:
> https://lore.kernel.org/r/20260326-add-emmc-t7-vim4-v5-0-d3f182b48e9d@aliel.fr
> ---
> Changes in v2:
> - Add netdev in CC.
> - Link to v1: https://lore.kernel.org/r/20260326-add-bcm43752-compatible-v1-1-b3b9a58ab38b@aliel.fr
> ---
> Documentation/devicetree/bindings/net/wireless/brcm,bcm4329-fmac.yaml | 1 +
> 1 file changed, 1 insertion(+)
^ permalink raw reply
* Re: [PATCH v4 3/6] arm64: dts: qcom: msm8953-flipkart-rimob: Enable display and GPU
From: Dmitry Baryshkov @ 2026-03-29 10:12 UTC (permalink / raw)
To: cristian_ci
Cc: Neil Armstrong, Jessica Zhang, David Airlie, Simona Vetter,
Maarten Lankhorst, Maxime Ripard, Thomas Zimmermann, Rob Herring,
Krzysztof Kozlowski, Conor Dooley, Bjorn Andersson, Konrad Dybcio,
dri-devel, devicetree, linux-kernel, linux-arm-msm,
~postmarketos/upstreaming, phone-devel
In-Reply-To: <O7THc5h8ZhgzNpklYKTGOnEZKlN4BtHZHjKZt2KErekNb3E-hizt2dw7xuJ8G6giEyivmvC0f6-eIfCT6fJkUA7_CVQwhAktCXfBqAVV_Zo=@protonmail.com>
On Sat, Mar 28, 2026 at 05:30:53PM +0000, cristian_ci wrote:
> On Friday, March 27th, 2026 at 23:57, Dmitry Baryshkov <dmitry.baryshkov@oss.qualcomm.com> wrote:
>
> > On Fri, Mar 27, 2026 at 03:30:49PM +0100, Cristian Cozzolino via B4 Relay wrote:
> > > From: Cristian Cozzolino <cristian_ci@protonmail.com>
> > >
> > > Add the description for the display panel found on this phone.
> > > And with this done we can also enable the GPU and set the zap shader
> > > firmware path.
> > >
> > > Signed-off-by: Cristian Cozzolino <cristian_ci@protonmail.com>
> > > ---
> > > .../arm64/boot/dts/qcom/msm8953-flipkart-rimob.dts | 73 ++++++++++++++++++++++
> > > 1 file changed, 73 insertions(+)
> > >
> >
> > Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@oss.qualcomm.com>
>
> I wonder if I should, instead, edit the compatible property by adding a
> second string (for the fallback), like this:
>
> compatible = "flipkart,rimob-panel-nt35532-cs", "novatek,nt35532";
>
> and, therefore, add "novatek,nt35532" string also to (patch 1/6)'s
> bindings example. Let me know what you think.
What would it mean? I think we usually don't include the IC into the
compat list for the panel, but feel free to prove me wrong.
--
With best wishes
Dmitry
^ permalink raw reply
* Re: [PATCH v4 2/6] drm/panel: Add driver for Novatek NT35532
From: Dmitry Baryshkov @ 2026-03-29 10:05 UTC (permalink / raw)
To: cristian_ci
Cc: Neil Armstrong, Jessica Zhang, David Airlie, Simona Vetter,
Maarten Lankhorst, Maxime Ripard, Thomas Zimmermann, Rob Herring,
Krzysztof Kozlowski, Conor Dooley, Bjorn Andersson, Konrad Dybcio,
dri-devel, devicetree, linux-kernel, linux-arm-msm,
~postmarketos/upstreaming, phone-devel
In-Reply-To: <20260327-rimob-new-features-v4-2-06edff9c4509@protonmail.com>
On Fri, Mar 27, 2026 at 03:30:48PM +0100, Cristian Cozzolino via B4 Relay wrote:
> From: Cristian Cozzolino <cristian_ci@protonmail.com>
>
> Add support for Novatek NT35532-based 1080p video mode DSI panel.
>
> Signed-off-by: Cristian Cozzolino <cristian_ci@protonmail.com>
> ---
> MAINTAINERS | 1 +
> drivers/gpu/drm/panel/Kconfig | 10 +
> drivers/gpu/drm/panel/Makefile | 1 +
> drivers/gpu/drm/panel/panel-novatek-nt35532.c | 796 ++++++++++++++++++++++++++
> 4 files changed, 808 insertions(+)
>
Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@oss.qualcomm.com>
--
With best wishes
Dmitry
^ permalink raw reply
* Re: [PATCH v2 2/3] arm64: dts: qcom: sdm670: add debug uart soc node
From: Dmitry Baryshkov @ 2026-03-29 9:55 UTC (permalink / raw)
To: pabloyoyoista
Cc: Bjorn Andersson, Konrad Dybcio, Rob Herring, Krzysztof Kozlowski,
Conor Dooley, linux-arm-msm, devicetree, linux-kernel,
Richard Acayan, ~postmarketos/upstreaming
In-Reply-To: <20260328-pabloyoyoista-debug-uart-on-rdacayan-next-v2-2-53abd9db8f0a@postmarketos.org>
On Sat, Mar 28, 2026 at 11:58:41PM +0100, Pablo Correa Gómez via B4 Relay wrote:
> From: Pablo Correa Gómez <pabloyoyoista@postmarketos.org>
>
> Values are taken from the other geni nodes
>
> Signed-off-by: Pablo Correa Gómez <pabloyoyoista@postmarketos.org>
> ---
> arch/arm64/boot/dts/qcom/sdm670.dtsi | 15 +++++++++++++++
> 1 file changed, 15 insertions(+)
>
Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@oss.qualcomm.com>
--
With best wishes
Dmitry
^ permalink raw reply
* Re: [PATCH v2 3/3] arm64: dts: qcom: sdm670-google-common: enable debug uart
From: Dmitry Baryshkov @ 2026-03-29 9:55 UTC (permalink / raw)
To: pabloyoyoista
Cc: Bjorn Andersson, Konrad Dybcio, Rob Herring, Krzysztof Kozlowski,
Conor Dooley, linux-arm-msm, devicetree, linux-kernel,
Richard Acayan, ~postmarketos/upstreaming
In-Reply-To: <20260328-pabloyoyoista-debug-uart-on-rdacayan-next-v2-3-53abd9db8f0a@postmarketos.org>
On Sat, Mar 28, 2026 at 11:58:42PM +0100, Pablo Correa Gómez via B4 Relay wrote:
> From: Pablo Correa Gómez <pabloyoyoista@postmarketos.org>
>
> This has been tested on the Pixel 3a with USB Cereal board
>
> Depends on
> https://lore.kernel.org/all/20260310002606.16413-5-mailingradian@gmail.com/
>
> Signed-off-by: Pablo Correa Gómez <pabloyoyoista@postmarketos.org>
> ---
> arch/arm64/boot/dts/qcom/sdm670-google-common.dtsi | 18 +++++++++++++++++-
> 1 file changed, 17 insertions(+), 1 deletion(-)
>
Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@oss.qualcomm.com>
--
With best wishes
Dmitry
^ permalink raw reply
* Re: [PATCH v2 5/7] arm64: dts: qcom: sm6125-xiaomi-ginkgo: Add PMI632 Type-C property
From: Dmitry Baryshkov @ 2026-03-29 9:52 UTC (permalink / raw)
To: Biswapriyo Nath
Cc: Bjorn Andersson, Konrad Dybcio, Rob Herring, Krzysztof Kozlowski,
Conor Dooley, Lee Jones, Pavel Machek, Sean Young,
Michael Turquette, Stephen Boyd, Martin Botka, linux-arm-msm,
devicetree, linux-kernel, linux-leds, linux-clk,
~postmarketos/upstreaming, phone-devel, stable, Konrad Dybcio
In-Reply-To: <20260329-ginkgo-add-usb-ir-vib-v2-5-870e0745e55e@gmail.com>
On Sun, Mar 29, 2026 at 04:48:00AM +0000, Biswapriyo Nath wrote:
> The USB-C port is used for powering external devices and transfer
> data from/to them.
>
> Reviewed-by: Konrad Dybcio <konrad.dybcio@oss.qualcomm.com>
> Signed-off-by: Biswapriyo Nath <nathbappai@gmail.com>
> ---
> .../boot/dts/qcom/sm6125-xiaomi-ginkgo-common.dtsi | 31 ++++++++++++++++++++++
> 1 file changed, 31 insertions(+)
>
Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@oss.qualcomm.com>
--
With best wishes
Dmitry
^ permalink raw reply
* Re: [PATCH 1/2] dt-bindings: arm: qcom: Add monaco-evk-ac-sku support
From: Krzysztof Kozlowski @ 2026-03-29 9:52 UTC (permalink / raw)
To: Umang Chheda
Cc: Bjorn Andersson, Konrad Dybcio, Rob Herring, Krzysztof Kozlowski,
Conor Dooley, Richard Cochran, linux-arm-msm, devicetree,
linux-kernel
In-Reply-To: <20260328-monaco-evk-ac-sku-v1-1-79d166fa5571@oss.qualcomm.com>
On Sat, Mar 28, 2026 at 05:11:17PM +0530, Umang Chheda wrote:
> Introduce new bindings for the monaco-evk-ac-sku,
> an IoT board based on the QCS8300-AC variant SoC.
Please wrap commit message according to Linux coding style / submission
process (neither too early nor over the limit):
https://elixir.bootlin.com/linux/v6.4-rc1/source/Documentation/process/submitting-patches.rst#L597
>
> Signed-off-by: Umang Chheda <umang.chheda@oss.qualcomm.com>
> ---
> Documentation/devicetree/bindings/arm/qcom.yaml | 1 +
> 1 file changed, 1 insertion(+)
>
> diff --git a/Documentation/devicetree/bindings/arm/qcom.yaml b/Documentation/devicetree/bindings/arm/qcom.yaml
> index ca880c105f3b..07053cc2ac1c 100644
> --- a/Documentation/devicetree/bindings/arm/qcom.yaml
> +++ b/Documentation/devicetree/bindings/arm/qcom.yaml
> @@ -918,6 +918,7 @@ properties:
> - enum:
> - arduino,monza
> - qcom,monaco-evk
> + - qcom,monaco-evk-ac-sku
Why adding name 'sku' to the compatible? What's the meaning here?
Best regards,
Krzysztof
^ permalink raw reply
* Re: [PATCH 1/7] dt-bindings: power: qcom-rpmpd: Split MSM8953 and SDM632
From: Dmitry Baryshkov @ 2026-03-29 9:51 UTC (permalink / raw)
To: Barnabás Czémán
Cc: Rob Herring, Krzysztof Kozlowski, Conor Dooley, Bjorn Andersson,
Ulf Hansson, Mathieu Poirier, Konrad Dybcio, Stephan Gerhold,
linux-arm-msm, devicetree, linux-kernel, linux-pm,
linux-remoteproc
In-Reply-To: <39a320e472ddc6d44c950a995b577e77@mainlining.org>
On Sat, Mar 28, 2026 at 09:22:19AM +0100, Barnabás Czémán wrote:
> On 2026-03-27 21:26, Dmitry Baryshkov wrote:
> > On Fri, Mar 27, 2026 at 09:11:43PM +0100, Barnabás Czémán wrote:
> > > Remove modem related bindings from MSM8953 rpmpd because MSM8953 MSS
> > > is using mss-supply as a regulator usually it is pm8953_s1.
> > > Split SDM632 bindings from MSM8953 because SDM632 is using mss-supply
> > > as a pm domain.
> > >
> > > Signed-off-by: Barnabás Czémán <barnabas.czeman@mainlining.org>
> > > ---
> > > .../devicetree/bindings/power/qcom,rpmpd.yaml | 1 +
> > > include/dt-bindings/power/qcom-rpmpd.h | 20
> > > +++++++++++++-------
> > > 2 files changed, 14 insertions(+), 7 deletions(-)
> > >
> > > diff --git a/Documentation/devicetree/bindings/power/qcom,rpmpd.yaml
> > > b/Documentation/devicetree/bindings/power/qcom,rpmpd.yaml
> > > index 8174ceeab572..659936d6a46e 100644
> > > --- a/Documentation/devicetree/bindings/power/qcom,rpmpd.yaml
> > > +++ b/Documentation/devicetree/bindings/power/qcom,rpmpd.yaml
> > > @@ -48,6 +48,7 @@ properties:
> > > - qcom,sc7280-rpmhpd
> > > - qcom,sc8180x-rpmhpd
> > > - qcom,sc8280xp-rpmhpd
> > > + - qcom,sdm632-rpmpd
> > > - qcom,sdm660-rpmpd
> > > - qcom,sdm670-rpmhpd
> > > - qcom,sdm845-rpmhpd
> > > diff --git a/include/dt-bindings/power/qcom-rpmpd.h
> > > b/include/dt-bindings/power/qcom-rpmpd.h
> > > index 4371ac941f29..2d82434b993c 100644
> > > --- a/include/dt-bindings/power/qcom-rpmpd.h
> > > +++ b/include/dt-bindings/power/qcom-rpmpd.h
> > > @@ -84,13 +84,11 @@
> > > #define QM215_VDDMX_AO MSM8917_VDDMX_AO
> > >
> > > /* MSM8953 Power Domain Indexes */
> > > -#define MSM8953_VDDMD 0
> > > -#define MSM8953_VDDMD_AO 1
> > > -#define MSM8953_VDDCX 2
> > > -#define MSM8953_VDDCX_AO 3
> > > -#define MSM8953_VDDCX_VFL 4
> > > -#define MSM8953_VDDMX 5
> > > -#define MSM8953_VDDMX_AO 6
> > > +#define MSM8953_VDDCX RPMPD_VDDCX
> > > +#define MSM8953_VDDCX_AO RPMPD_VDDCX_AO
> > > +#define MSM8953_VDDCX_VFL RPMPD_VDDCX_VFL
> > > +#define MSM8953_VDDMX RPMPD_VDDMX
> > > +#define MSM8953_VDDMX_AO RPMPD_VDDMX_AO
> >
> > Well, no. This is an ABI break. It will make previous DT to stop from
> > working. You can drop unused indices, but you can not change the values
> > used by the existing domains.
> Do these indices never can be changed?
You can add new indices and you can (with some care) drop existing
incorrecr or unused ones. You can't reassign indices though. The rule of
thumb is that old DTs should continue to work without rebuilding.
> >
> > >
> > > /* MSM8974 Power Domain Indexes */
> > > #define MSM8974_VDDCX 0
> > > @@ -156,6 +154,14 @@
> > > #define QCS404_LPIMX 5
> > > #define QCS404_LPIMX_VFL 6
> > >
> > > +/* SDM632 Power Domain Indexes */
> > > +#define SDM632_VDDMD 0
> > > +#define SDM632_VDDCX 1
> > > +#define SDM632_VDDCX_AO 2
> > > +#define SDM632_VDDCX_VFL 3
> > > +#define SDM632_VDDMX 4
> > > +#define SDM632_VDDMX_AO 5
> >
> > Please use RPMHPD_* instead of introducing new entries.
> I do not understand completely, should I use RPHPD bindings in rpmpd driver
> or
> I should use rpmhpd driver for SDM632?
Sorry, I meant RPMPD_*
> >
> > > +
> > > /* SDM660 Power Domains */
> > > #define SDM660_VDDCX RPMPD_VDDCX
> > > #define SDM660_VDDCX_AO RPMPD_VDDCX_AO
> > >
> > > --
> > > 2.53.0
> > >
--
With best wishes
Dmitry
^ permalink raw reply
* Re: [PATCH 1/1] dt-bindings: media: convert hix5hd2-ir to DT schema
From: Krzysztof Kozlowski @ 2026-03-29 9:45 UTC (permalink / raw)
To: Pranav Kharche
Cc: Rob Herring, Krzysztof Kozlowski, Conor Dooley,
Mauro Carvalho Chehab, linux-media, devicetree
In-Reply-To: <20260328084238.201452-2-pranavkharche7@gmail.com>
On Sat, Mar 28, 2026 at 02:12:38PM +0530, Pranav Kharche wrote:
> Convert the legacy plaintext binding for HiSilicon hix5hd2 IR remote
> controller to JSON Schema (DT schema) format in YAML.
>
> This binding documents the infrared remote receiver found in HiSilicon
> SoCs such as hix5hd2 and hi3796cv300. The conversion includes:
>
> - Standardized property definitions with types and constraints
Drop
> - Reference to rc.yaml base schema for remote controller properties
Drop
> - Addition of include directives for interrupt-controller bindings
Drop
> - Proper example with GIC interrupt specifiers
Drop
> - Schema validation support for device tree sources
Drop
>
> The new schema enables:
> - Validation improvement
Drop
>
> tested with: make dt_binding_check DT_SCHEMA_FILES=...
> All schema validation checks pass.
Drop
Please write useful commit msgs, meaning you do not need to state
obvious things. Plenty of examples in git log.
What you MUST say here is documenting the changes you done to the
binding. You removed existing property which is not explained at all,
introduces undocumented ABI and adds new warnings. No, seriously, no.
And if you TESTED this you would see errors, so back to basic
requirements of schema conversion - see my posts on social.kernel.org.
>
> Signed-off-by: Pranav Kharche <pranavkharche7@gmail.com>
> ---
> .../devicetree/bindings/media/hix5hd2-ir.txt | 26 ---------
> .../devicetree/bindings/media/hix5hd2-ir.yaml | 53 +++++++++++++++++++
> 2 files changed, 53 insertions(+), 26 deletions(-)
> delete mode 100644 Documentation/devicetree/bindings/media/hix5hd2-ir.txt
> create mode 100644 Documentation/devicetree/bindings/media/hix5hd2-ir.yaml
>
> diff --git a/Documentation/devicetree/bindings/media/hix5hd2-ir.txt b/Documentation/devicetree/bindings/media/hix5hd2-ir.txt
> deleted file mode 100644
> index ca4cf774662e..000000000000
> --- a/Documentation/devicetree/bindings/media/hix5hd2-ir.txt
> +++ /dev/null
> @@ -1,26 +0,0 @@
> -Device-Tree bindings for hix5hd2 ir IP
> -
> -Required properties:
> - - compatible: Should contain "hisilicon,hix5hd2-ir", or:
> - - "hisilicon,hi3796cv300-ir" for Hi3796CV300 IR device.
> - - reg: Base physical address of the controller and length of memory
> - mapped region.
> - - interrupts: interrupt-specifier for the sole interrupt generated by
> - the device. The interrupt specifier format depends on the interrupt
> - controller parent.
> - - clocks: clock phandle and specifier pair.
> -
> -Optional properties:
> - - linux,rc-map-name: see rc.txt file in the same directory.
> - - hisilicon,power-syscon: DEPRECATED. Don't use this in new dts files.
> - Provide correct clocks instead.
> -
> -Example node:
> -
> - ir: ir@f8001000 {
> - compatible = "hisilicon,hix5hd2-ir";
> - reg = <0xf8001000 0x1000>;
> - interrupts = <0 47 4>;
> - clocks = <&clock HIX5HD2_IR_CLOCK>;
> - linux,rc-map-name = "rc-tivo";
> - };
> diff --git a/Documentation/devicetree/bindings/media/hix5hd2-ir.yaml b/Documentation/devicetree/bindings/media/hix5hd2-ir.yaml
> new file mode 100644
> index 000000000000..91cba6ec88c5
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/media/hix5hd2-ir.yaml
Filename must match the compatible, choose one.
> @@ -0,0 +1,53 @@
> +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
> +%YAML 1.2
> +---
> +$id: http://devicetree.org/schemas/media/hix5hd2-ir.yaml#
> +$schema: http://devicetree.org/meta-schemas/core.yaml#
> +
> +title: HiSilicon Hix5hd2 infrared remote controller
> +
> +maintainers:
> + - Pranav Kharche <pranavkharche7@gmail.com>
> +
> +allOf:
> + - $ref: rc.yaml#
> +
> +description: |
Do not need '|' unless you need to preserve formatting.
> + This binding describes the infrared remote controller found in
So description describes that your binding describes... No, drop.
Explain the hardware and if you do not have any explanation, no need to
state obvious and paste here compatibles.
Best regards,
Krzysztof
^ permalink raw reply
* Re: [PATCH 1/7] dt-bindings: power: qcom-rpmpd: Split MSM8953 and SDM632
From: Krzysztof Kozlowski @ 2026-03-29 9:37 UTC (permalink / raw)
To: Barnabás Czémán
Cc: Rob Herring, Krzysztof Kozlowski, Conor Dooley, Bjorn Andersson,
Ulf Hansson, Mathieu Poirier, Konrad Dybcio, Stephan Gerhold,
linux-arm-msm, devicetree, linux-kernel, linux-pm,
linux-remoteproc
In-Reply-To: <20260327-sdm632-rpmpd-v1-1-6098dc997d66@mainlining.org>
On Fri, Mar 27, 2026 at 09:11:43PM +0100, Barnabás Czémán wrote:
> Remove modem related bindings from MSM8953 rpmpd because MSM8953 MSS
> is using mss-supply as a regulator usually it is pm8953_s1.
> Split SDM632 bindings from MSM8953 because SDM632 is using mss-supply
> as a pm domain.
>
> Signed-off-by: Barnabás Czémán <barnabas.czeman@mainlining.org>
> ---
> .../devicetree/bindings/power/qcom,rpmpd.yaml | 1 +
> include/dt-bindings/power/qcom-rpmpd.h | 20 +++++++++++++-------
> 2 files changed, 14 insertions(+), 7 deletions(-)
>
> diff --git a/Documentation/devicetree/bindings/power/qcom,rpmpd.yaml b/Documentation/devicetree/bindings/power/qcom,rpmpd.yaml
> index 8174ceeab572..659936d6a46e 100644
> --- a/Documentation/devicetree/bindings/power/qcom,rpmpd.yaml
> +++ b/Documentation/devicetree/bindings/power/qcom,rpmpd.yaml
> @@ -48,6 +48,7 @@ properties:
> - qcom,sc7280-rpmhpd
> - qcom,sc8180x-rpmhpd
> - qcom,sc8280xp-rpmhpd
> + - qcom,sdm632-rpmpd
> - qcom,sdm660-rpmpd
> - qcom,sdm670-rpmhpd
> - qcom,sdm845-rpmhpd
> diff --git a/include/dt-bindings/power/qcom-rpmpd.h b/include/dt-bindings/power/qcom-rpmpd.h
> index 4371ac941f29..2d82434b993c 100644
> --- a/include/dt-bindings/power/qcom-rpmpd.h
> +++ b/include/dt-bindings/power/qcom-rpmpd.h
> @@ -84,13 +84,11 @@
> #define QM215_VDDMX_AO MSM8917_VDDMX_AO
>
> /* MSM8953 Power Domain Indexes */
> -#define MSM8953_VDDMD 0
ABI break / impact and due to two changes combined I don't really
understand why. Why MSS using mss-supply makes this ABI invalid/wrong?
> -#define MSM8953_VDDMD_AO 1
> -#define MSM8953_VDDCX 2
> -#define MSM8953_VDDCX_AO 3
> -#define MSM8953_VDDCX_VFL 4
> -#define MSM8953_VDDMX 5
> -#define MSM8953_VDDMX_AO 6
> +#define MSM8953_VDDCX RPMPD_VDDCX
> +#define MSM8953_VDDCX_AO RPMPD_VDDCX_AO
> +#define MSM8953_VDDCX_VFL RPMPD_VDDCX_VFL
> +#define MSM8953_VDDMX RPMPD_VDDMX
> +#define MSM8953_VDDMX_AO RPMPD_VDDMX_AO
I don't see how this is related to new compatible and SDM632.
>
> /* MSM8974 Power Domain Indexes */
> #define MSM8974_VDDCX 0
> @@ -156,6 +154,14 @@
> #define QCS404_LPIMX 5
> #define QCS404_LPIMX_VFL 6
Best regards,
Krzysztof
^ permalink raw reply
* Re: [PATCH v2 2/2] ARM: dts: st: spear: rename thermal_flags to st,thermal-flags
From: Krzysztof Kozlowski @ 2026-03-29 9:34 UTC (permalink / raw)
To: Gopi Krishna Menon
Cc: rafael, daniel.lezcano, rui.zhang, lukasz.luba, robh, krzk+dt,
vireshk, conor+dt, linux-pm, devicetree, linux-kernel,
linux-arm-kernel, soc, daniel.baluta, simona.toaca, d-gole,
m-chawdhry
In-Reply-To: <20260329-starfish-of-eternal-storm-f16de5@quoll>
On 29/03/2026 11:31, Krzysztof Kozlowski wrote:
> On Sun, Mar 29, 2026 at 11:45:20AM +0530, Gopi Krishna Menon wrote:
>> st,thermal-flags is a required property in SPEAr Thermal Sensor node,
>> which is incorrectly written as thermal_flags in spear13xx.dtsi.
>>
>> Rename thermal_flags to st,thermal-flags to fix the property name
>
> Does this have an impact? If yes, then why no fixes? If no, then why
> not? How this could ever worked? Maybe this is completely unnecessary.
>
> We already talked about this and I don't get why this change is neeeded
> and why we discuss the same problem.
and by "this change" I meant, "rename" part, instead of "removal".
Your task is analyze entire code, understand what was wrong and provide
proper solution.
Best regards,
Krzysztof
^ permalink raw reply
* Re: [PATCH v2 2/2] ARM: dts: st: spear: rename thermal_flags to st,thermal-flags
From: Krzysztof Kozlowski @ 2026-03-29 9:31 UTC (permalink / raw)
To: Gopi Krishna Menon
Cc: rafael, daniel.lezcano, rui.zhang, lukasz.luba, robh, krzk+dt,
vireshk, conor+dt, linux-pm, devicetree, linux-kernel,
linux-arm-kernel, soc, daniel.baluta, simona.toaca, d-gole,
m-chawdhry
In-Reply-To: <20260329061523.98346-3-krishnagopi487@gmail.com>
On Sun, Mar 29, 2026 at 11:45:20AM +0530, Gopi Krishna Menon wrote:
> st,thermal-flags is a required property in SPEAr Thermal Sensor node,
> which is incorrectly written as thermal_flags in spear13xx.dtsi.
>
> Rename thermal_flags to st,thermal-flags to fix the property name
Does this have an impact? If yes, then why no fixes? If no, then why
not? How this could ever worked? Maybe this is completely unnecessary.
We already talked about this and I don't get why this change is neeeded
and why we discuss the same problem.
Best regards,
Krzysztof
^ permalink raw reply
* Re: [PATCH v2 1/2] dt-bindings: thermal: st,thermal-spear1340: convert to dtschema
From: Krzysztof Kozlowski @ 2026-03-29 9:29 UTC (permalink / raw)
To: Gopi Krishna Menon
Cc: rafael, daniel.lezcano, rui.zhang, lukasz.luba, robh, krzk+dt,
vireshk, conor+dt, linux-pm, devicetree, linux-kernel,
linux-arm-kernel, soc, daniel.baluta, simona.toaca, d-gole,
m-chawdhry
In-Reply-To: <20260329061523.98346-2-krishnagopi487@gmail.com>
On Sun, Mar 29, 2026 at 11:45:19AM +0530, Gopi Krishna Menon wrote:
> Convert the SPEAr Thermal Sensor bindings to DT schema.
>
> Signed-off-by: Gopi Krishna Menon <krishnagopi487@gmail.com>
> ---
> Changes since v1:
> - Changed unevaluatedProperties to additionalProperties
Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@oss.qualcomm.com>
Best regards,
Krzysztof
^ permalink raw reply
* Re: [PATCH v2 2/7] dt-bindings: clock: qcom, dispcc-sm6125: Add #reset-cells property
From: Krzysztof Kozlowski @ 2026-03-29 9:28 UTC (permalink / raw)
To: Biswapriyo Nath
Cc: Bjorn Andersson, Konrad Dybcio, Rob Herring, Krzysztof Kozlowski,
Conor Dooley, Lee Jones, Pavel Machek, Sean Young,
Michael Turquette, Stephen Boyd, Martin Botka, linux-arm-msm,
devicetree, linux-kernel, linux-leds, linux-clk,
~postmarketos/upstreaming, phone-devel, stable, kernel test robot
In-Reply-To: <20260329-amorphous-happy-deer-cea083@quoll>
On 29/03/2026 11:21, Krzysztof Kozlowski wrote:
> On Sun, Mar 29, 2026 at 04:47:57AM +0000, Biswapriyo Nath wrote:
>> The '#reset-cells' property is permitted for the SM6125 SoC clock
>> controllers, but not listed as a valid property.
>
> Any reason why this binding file is the only dispcc not referencing
> qcom,gcc.yaml? It should and it would solve the error. Look at other
> files.
... and you also need to update the example.
Best regards,
Krzysztof
^ permalink raw reply
* Re: [PATCH v2 2/7] dt-bindings: clock: qcom, dispcc-sm6125: Add #reset-cells property
From: Krzysztof Kozlowski @ 2026-03-29 9:21 UTC (permalink / raw)
To: Biswapriyo Nath
Cc: Bjorn Andersson, Konrad Dybcio, Rob Herring, Krzysztof Kozlowski,
Conor Dooley, Lee Jones, Pavel Machek, Sean Young,
Michael Turquette, Stephen Boyd, Martin Botka, linux-arm-msm,
devicetree, linux-kernel, linux-leds, linux-clk,
~postmarketos/upstreaming, phone-devel, stable, kernel test robot
In-Reply-To: <20260329-ginkgo-add-usb-ir-vib-v2-2-870e0745e55e@gmail.com>
On Sun, Mar 29, 2026 at 04:47:57AM +0000, Biswapriyo Nath wrote:
> The '#reset-cells' property is permitted for the SM6125 SoC clock
> controllers, but not listed as a valid property.
Any reason why this binding file is the only dispcc not referencing
qcom,gcc.yaml? It should and it would solve the error. Look at other
files.
Best regards,
Krzysztof
^ permalink raw reply
* Re: [PATCH v4 1/8] mmc: sdhci-of-k1: enable essential clock, infrastructure for SD operation
From: Vincent Legoll @ 2026-03-29 9:20 UTC (permalink / raw)
To: Iker Pedrosa
Cc: Ulf Hansson, Rob Herring, Krzysztof Kozlowski, Conor Dooley,
Adrian Hunter, Paul Walmsley, Palmer Dabbelt, Albert Ou,
Alexandre Ghiti, Yixun Lan, Yixun Lan, Michael Opdenacker,
Javier Martinez Canillas, linux-mmc, devicetree, linux-riscv,
spacemit, linux-kernel, Iker Pedrosa, Anand Moon, Trevor Gamblin
In-Reply-To: <20260323-orangepi-sd-card-uhs-v4-0-567c9775fd0e@gmail.com>
Hello,
I applied this series on top of cbfffcca2bf0622b601b7eaf477aa29035169184
(linux mainline from yesterday) and successfully booted the resulting
kernel from an SD card on an OrangePi-RV2 (with the vendor u-boot from
the SPI flash).
So if you want, you can add my: Tested-by: Vincent Legoll
<legoll@online.fr> # OrangePi-RV2 to the relevant patches from this
series Thanks Regards
^ permalink raw reply
* Re: [PATCH v2] dt-bindings: i2c: intel,ixp4xx-i2c: Convert to DT schema
From: Krzysztof Kozlowski @ 2026-03-29 9:10 UTC (permalink / raw)
To: Shi Hao
Cc: krzk+dt, robh, andi.shyti, conor+dt, linux-i2c, devicetree,
linux-kernel
In-Reply-To: <20260328101157.84191-1-i.shihao.999@gmail.com>
On Sat, Mar 28, 2026 at 03:41:57PM +0530, Shi Hao wrote:
> Convert the IOP3xx and IXP4xx XScale bindings to DT schema. This
> conversion also adds the <irq.h> header file to the example section, since
> IRQ_TYPE_LEVEL_LOW macro is used. This ensures the examples validate
> correctly.
Drop last two sentences, irrelevant. I asked about changes in the
binding, not in the example. The example is not relevant here and we
never ask to document changes in it.
Did binding have interrupts? No.
Does new binding have interrupts? Yes.
Does your commit msg explains adding them? No.
Best regards,
Krzysztof
^ permalink raw reply
* [PATCH v8 2/6] mfd: add NXP MC33978/MC34978 core driver
From: Oleksij Rempel @ 2026-03-29 9:05 UTC (permalink / raw)
To: Guenter Roeck, Rob Herring, Krzysztof Kozlowski, Conor Dooley,
Lee Jones, Peter Rosin, Linus Walleij
Cc: Oleksij Rempel, kernel, linux-kernel, devicetree, linux-hwmon,
linux-gpio, David Jander
In-Reply-To: <20260329090601.532477-1-o.rempel@pengutronix.de>
Add core Multi-Function Device (MFD) driver for the NXP MC33978 and
MC34978 Multiple Switch Detection Interfaces (MSDI).
The MC33978/MC34978 devices provide 22 switch detection inputs, analog
multiplexing (AMUX), and comprehensive hardware fault detection.
This core driver handles:
- SPI communications via a custom regmap bus to support the device's
pipelined two-frame MISO response requirement.
- Power sequencing for the VDDQ (logic) and VBATP (battery) regulators.
- Interrupt demultiplexing, utilizing an irq_domain to provide 22 virtual
IRQs for switch state changes and 1 virtual IRQ for hardware faults.
- Inline status harvesting from the SPI MSB to detect and trigger events
without requiring dedicated status register polling.
Child devices (pinctrl, hwmon, mux) are instantiated by the core driver
from match data.
Signed-off-by: Oleksij Rempel <o.rempel@pengutronix.de>
---
changes v8:
- Fix TOCTOU race condition in SPI event harvesting loop by grabbing
harvested_flags before hardware reads.
- Fix broken hierarchical IRQ allocation by replacing
irq_domain_set_hwirq_and_chip() with irq_domain_set_info() and passing
the handle_simple_irq flow handler.
- Fix out-of-bounds stack read and endianness bug in for_each_set_bit() by
typing fired_pins as unsigned long instead of casting u32.
- Prevent DMA cacheline corruption by explicitly aligning rx_frame with
____cacheline_aligned to separate it from tx_frame.
- Prevent spurious IRQs by verifying irq_find_mapping() returns non-zero
before calling handle_nested_irq().
- Prevent missed transient hardware faults by explicitly evaluating
hw_flags in mc33978_handle_fault_condition().
- Fix missing memory barrier in mc33978_harvest_status() with
smp_mb__after_atomic() to ensure harvested_flags visibility.
- Fix devres use-after-free teardown race by using INIT_WORK and a custom
cancel action after the IRQ domain is destroyed, instead of
devm_work_autocancel.
- Prevent spurious pin interrupts on boot by priming cached_pin_state via
a regmap_read() during probe before enabling IRQs.
- Implement .irq_set_wake callback to support system wake from
hardware faults and switch state changes.
changes v7:
- Fix event handling race condition with smp_mb()
- Replace INIT_WORK() with devm_work_autocancel()
changes v6:
- Remove the hardcoded bypass in irq_set_type to allow child drivers to
configure the FAULT line for edge-triggering.
- Implement software edge-detection for FAULT interrupt.
- Add MC33978_FAULT_ALARM_MASK to the shared header for child devices
- Use READ_ONCE() and WRITE_ONCE() for lockless shared state variables
(cached_pin_mask, irq_rise, irq_fall, bus_fault_active,
cached_fault_active) accessed across the SPI harvesting context and
the event worker.
- Add an if (hwirq < MC33978_NUM_PINS) guard in irq_mask() and
irq_unmask() to prevent the FAULT hwirq (22) from altering the
physical pin mask registers.
- Lowercase the error strings in dev_err_probe()
- Add inline comments explaining the irq_map fallback behavior
changes v5:
- no changes
changes v4:
- Removed .of_compatible strings from the mfd_cell arrays
changes v3:
- Select IRQ_DOMAIN_HIERARCHY in Kconfig
- Add .alloc and .free callbacks to irq_domain_ops to support hierarchical
IRQ domains
- Set IRQ_DOMAIN_FLAG_HIERARCHY flag on the core MFD irq_domain
- replace manual lock/unlock with guard()
changes v2:
- Rewrite the driver header comment
- Explicitly reject IRQ_TYPE_LEVEL_HIGH and IRQ_TYPE_LEVEL_LOW in
mc33978_irq_set_type() to correctly reflect the hardware's edge-only
interrupt capabilities.
- Pass the hardware fault IRQ to the hwmon child driver via mfd_cell
resources, rather than requiring the child to parse the parent's irq_domain.
- Ensure the Kconfig strictly depends on OF and SPI
---
drivers/mfd/Kconfig | 15 +
drivers/mfd/Makefile | 2 +
drivers/mfd/mc33978.c | 988 ++++++++++++++++++++++++++++++++++++
include/linux/mfd/mc33978.h | 92 ++++
4 files changed, 1097 insertions(+)
create mode 100644 drivers/mfd/mc33978.c
create mode 100644 include/linux/mfd/mc33978.h
diff --git a/drivers/mfd/Kconfig b/drivers/mfd/Kconfig
index 7192c9d1d268..6dc9554822c9 100644
--- a/drivers/mfd/Kconfig
+++ b/drivers/mfd/Kconfig
@@ -2566,6 +2566,21 @@ config MFD_UPBOARD_FPGA
To compile this driver as a module, choose M here: the module will be
called upboard-fpga.
+config MFD_MC33978
+ tristate "NXP MC33978/MC34978 industrial input controller core"
+ depends on OF
+ depends on SPI
+ select IRQ_DOMAIN_HIERARCHY
+ select MFD_CORE
+ select REGMAP
+ help
+ Support for the NXP MC33978/MC34978 industrial input controllers
+ using the SPI interface.
+
+ This driver provides common support for accessing the device.
+ Additional drivers must be enabled in order to use the functionality
+ of the device.
+
config MFD_MAX7360
tristate "Maxim MAX7360 I2C IO Expander"
depends on I2C
diff --git a/drivers/mfd/Makefile b/drivers/mfd/Makefile
index e75e8045c28a..dcd99315f683 100644
--- a/drivers/mfd/Makefile
+++ b/drivers/mfd/Makefile
@@ -122,6 +122,8 @@ obj-$(CONFIG_MFD_MC13XXX) += mc13xxx-core.o
obj-$(CONFIG_MFD_MC13XXX_SPI) += mc13xxx-spi.o
obj-$(CONFIG_MFD_MC13XXX_I2C) += mc13xxx-i2c.o
+obj-$(CONFIG_MFD_MC33978) += mc33978.o
+
obj-$(CONFIG_MFD_PF1550) += pf1550.o
obj-$(CONFIG_MFD_NCT6694) += nct6694.o
diff --git a/drivers/mfd/mc33978.c b/drivers/mfd/mc33978.c
new file mode 100644
index 000000000000..ae8706b40cd4
--- /dev/null
+++ b/drivers/mfd/mc33978.c
@@ -0,0 +1,988 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (C) 2024 David Jander <david@protonic.nl>, Protonic Holland
+ * Copyright (C) 2026 Oleksij Rempel <kernel@pengutronix.de>, Pengutronix
+ *
+ * MC33978/MC34978 Multiple Switch Detection Interface - MFD Core Driver
+ *
+ * Driver Architecture:
+ * This is the core MFD driver handling the physical SPI interface, power
+ * management, and central interrupt routing. It instantiates the following
+ * child devices:
+ * - pinctrl: For GPIO read/write and wetting current configuration.
+ * - hwmon: For hardware fault monitoring (tLIM, over/under-voltage).
+ * - mux: For the 24-to-1 analog multiplexer (AMUX).
+ *
+ * Custom SPI Regmap & Event Harvesting:
+ * The device uses a non-standard pipelined SPI protocol where the MISO
+ * response logically lags the MOSI command by one frame. Furthermore, the
+ * hardware embeds volatile global status bits (INT_flg, FAULT_STAT) into the
+ * high byte of almost every SPI response (with specific exceptions handled by
+ * the decoder). This core implements a custom regmap_bus to handle the
+ * 2-frame dummy fetches and transparently "harvests" these status bits in
+ * the background to schedule event processing.
+ *
+ * Interrupt Quirks & Limitations:
+ * - Clear-on-Read: The physical INT_B line is directly tied to the INT_flg
+ * bit. The hardware deasserts INT_B immediately upon *any* SPI transfer
+ * that returns INT_flg. Harvesting this bit from all SPI traffic is the
+ * ONLY way to know this device triggered an interrupt (crucial for shared
+ * IRQ lines).
+ * - Stateless Pin Edge Detection: The hardware lacks per-pin interrupt status
+ * registers. To determine which pin triggered an event, the driver must
+ * read the current pin states and XOR them against a previously cached state.
+ * - Missed Short Pulses: Because pin interrupts are state-derived rather than
+ * hardware-latched, very short physical pulses (shorter than the SPI read
+ * latency) will be missed entirely if the pin reverts to its original state
+ * before the READ_IN register is sampled by the IRQ thread.
+ * - Edge-Only Pin Interrupts: The hardware only asserts INT_B on a state
+ * change. It cannot continuously assert an interrupt while a pin is held at a
+ * specific logic level. Consequently, the driver strictly emulates edge
+ * interrupts (RISING/FALLING) and explicitly rejects LEVEL interrupt
+ * configurations to prevent consumer misalignment.
+ */
+
+#include <linux/array_size.h>
+#include <linux/atomic.h>
+#include <linux/bitfield.h>
+#include <linux/bits.h>
+#include <linux/cache.h>
+#include <linux/cleanup.h>
+#include <linux/device.h>
+#include <linux/devm-helpers.h>
+#include <linux/interrupt.h>
+#include <linux/irq.h>
+#include <linux/irqdomain.h>
+#include <linux/mfd/core.h>
+#include <linux/mod_devicetable.h>
+#include <linux/module.h>
+#include <linux/of_platform.h>
+#include <linux/property.h>
+#include <linux/regmap.h>
+#include <linux/regulator/consumer.h>
+#include <linux/spi/spi.h>
+#include <linux/string.h>
+
+#include <linux/mfd/mc33978.h>
+
+#define MC33978_DRV_NAME "mc33978"
+
+/* Device identification signature returned by CHECK register */
+#define MC33978_CHECK_SIGNATURE 0x123456
+
+/*
+ * Pipelined two-frame SPI transfer:
+ * [REQ] - Transmits command/write-data, receives dummy/previous response
+ * [PIPE] - Transmits dummy CHECK, receives actual response to current command
+ */
+enum mc33978_frame_index {
+ MC33978_FRAME_REQ = 0,
+ MC33978_FRAME_PIPE,
+ MC33978_FRAME_COUNT
+};
+
+/* SPI frame byte offsets (transmitted MSB first) */
+enum mc33978_frame_offset {
+ MC33978_FRAME_CMD = 0,
+ MC33978_FRAME_DATA_HI,
+ MC33978_FRAME_DATA_MID,
+ MC33978_FRAME_DATA_LO
+};
+
+#define MC33978_FRAME_LEN 4
+
+/* Regmap internal value buffer offsets */
+enum mc33978_payload_offset {
+ MC33978_PAYLOAD_HI = 0,
+ MC33978_PAYLOAD_MID,
+ MC33978_PAYLOAD_LO
+};
+
+#define MC33978_PAYLOAD_LEN 3
+
+/*
+ * SPI Command Byte (FRAME_CMD).
+ * Maps to frame bit [24] in the datasheet.
+ */
+#define MC33978_CMD_BYTE_WRITE BIT(0)
+
+/* High Payload Byte Masks (FRAME_DATA_HI / PAYLOAD_HI). */
+#define MC33978_HI_BYTE_STAT_FAULT BIT(7) /* Maps to frame bit [23] */
+#define MC33978_HI_BYTE_STAT_INT BIT(6) /* Maps to frame bit [22] */
+
+#define MC33978_HI_BYTE_STATUS_MASK (MC33978_HI_BYTE_STAT_FAULT | \
+ MC33978_HI_BYTE_STAT_INT)
+
+/* Maps to frame bits [21:16] */
+#define MC33978_HI_BYTE_DATA_MASK GENMASK(5, 0)
+
+#define MC33978_CACHE_SG_PIN_MASK GENMASK(13, 0)
+#define MC33978_CACHE_SP_PIN_MASK GENMASK(21, 14)
+
+#define MC33978_SG_PIN_MASK GENMASK(13, 0)
+#define MC33978_SP_PIN_MASK GENMASK(7, 0)
+
+struct mc33978_data {
+ const struct mfd_cell *cells;
+ int num_cells;
+};
+
+struct mc33978_mfd_priv {
+ struct spi_device *spi;
+ struct regmap *map;
+
+ struct regulator *vddq;
+ struct regulator *vbatp;
+
+ /* Protects event processing loop and hardware state machine */
+ struct mutex event_lock;
+ struct work_struct event_work;
+ atomic_t is_handling;
+ atomic_t harvested_flags;
+ u32 cached_pin_state;
+ u32 cached_pin_mask;
+ u32 irq_rise;
+ u32 irq_fall;
+
+ /* Protects IRQ mask registers and cached IRQ state */
+ struct mutex irq_lock;
+ struct irq_domain *domain;
+
+ /* Pre-built SPI messages */
+ struct spi_message msg_read;
+ struct spi_message msg_write;
+ struct spi_transfer xfer_read[MC33978_FRAME_COUNT];
+ struct spi_transfer xfer_write;
+
+ bool cached_fault_active;
+ bool bus_fault_active;
+
+ /* DMA buffers at the end */
+ u8 tx_frame[MC33978_FRAME_COUNT][MC33978_FRAME_LEN] ____cacheline_aligned;
+ u8 rx_frame[MC33978_FRAME_COUNT][MC33978_FRAME_LEN] ____cacheline_aligned;
+};
+
+static void mc33978_irq_mask(struct irq_data *data)
+{
+ struct mc33978_mfd_priv *mc = irq_data_get_irq_chip_data(data);
+ irq_hw_number_t hwirq = irqd_to_hwirq(data);
+
+ if (hwirq < MC33978_NUM_PINS)
+ WRITE_ONCE(mc->cached_pin_mask,
+ READ_ONCE(mc->cached_pin_mask) & ~BIT(hwirq));
+}
+
+static void mc33978_irq_unmask(struct irq_data *data)
+{
+ struct mc33978_mfd_priv *mc = irq_data_get_irq_chip_data(data);
+ irq_hw_number_t hwirq = irqd_to_hwirq(data);
+
+ if (hwirq < MC33978_NUM_PINS)
+ WRITE_ONCE(mc->cached_pin_mask,
+ READ_ONCE(mc->cached_pin_mask) | BIT(hwirq));
+}
+
+static void mc33978_irq_bus_lock(struct irq_data *data)
+{
+ struct mc33978_mfd_priv *mc = irq_data_get_irq_chip_data(data);
+
+ mutex_lock(&mc->irq_lock);
+}
+
+/**
+ * mc33978_irq_bus_sync_unlock() - Sync cached IRQ mask to hardware and unlock
+ * @data: IRQ data
+ *
+ * Writes the cached interrupt mask to the hardware IE_SG and IE_SP registers,
+ * then releases the IRQ lock. This is where the actual hardware update occurs
+ * after mask/unmask operations.
+ */
+static void mc33978_irq_bus_sync_unlock(struct irq_data *data)
+{
+ struct mc33978_mfd_priv *mc = irq_data_get_irq_chip_data(data);
+ u32 sg_mask, sp_mask, cached_mask;
+ int ret;
+
+ cached_mask = READ_ONCE(mc->cached_pin_mask);
+
+ /*
+ * Split the cached 22-bit pin mask into hardware register format:
+ * - SG pins: bits [13:0] (14 pins, mask 0x3FFF)
+ * - SP pins: bits [21:14] (8 pins, mask 0xFF)
+ */
+ sg_mask = FIELD_GET(MC33978_CACHE_SG_PIN_MASK, cached_mask);
+ sp_mask = FIELD_GET(MC33978_CACHE_SP_PIN_MASK, cached_mask);
+
+ ret = regmap_update_bits(mc->map, MC33978_REG_IE_SG,
+ MC33978_SG_PIN_MASK, sg_mask);
+ if (ret)
+ goto unlock;
+
+ ret = regmap_update_bits(mc->map, MC33978_REG_IE_SP,
+ MC33978_SP_PIN_MASK, sp_mask);
+unlock:
+ if (ret)
+ dev_err(&mc->spi->dev, "failed to sync IRQ mask to hardware: %d\n",
+ ret);
+
+ mutex_unlock(&mc->irq_lock);
+}
+
+static int mc33978_irq_set_type(struct irq_data *data, unsigned int type)
+{
+ struct mc33978_mfd_priv *mc = irq_data_get_irq_chip_data(data);
+ irq_hw_number_t hwirq = irqd_to_hwirq(data);
+ u32 mask = BIT(hwirq);
+
+ if (type & (IRQ_TYPE_LEVEL_HIGH | IRQ_TYPE_LEVEL_LOW))
+ return -EINVAL;
+
+ if (type & IRQ_TYPE_EDGE_RISING)
+ WRITE_ONCE(mc->irq_rise, READ_ONCE(mc->irq_rise) | mask);
+ else
+ WRITE_ONCE(mc->irq_rise, READ_ONCE(mc->irq_rise) & ~mask);
+
+ if (type & IRQ_TYPE_EDGE_FALLING)
+ WRITE_ONCE(mc->irq_fall, READ_ONCE(mc->irq_fall) | mask);
+ else
+ WRITE_ONCE(mc->irq_fall, READ_ONCE(mc->irq_fall) & ~mask);
+
+ return 0;
+}
+
+static int mc33978_irq_set_wake(struct irq_data *data, unsigned int on)
+{
+ struct mc33978_mfd_priv *mc = irq_data_get_irq_chip_data(data);
+
+ return irq_set_irq_wake(mc->spi->irq, on);
+}
+
+static struct irq_chip mc33978_irq_chip = {
+ .name = MC33978_DRV_NAME,
+ .irq_mask = mc33978_irq_mask,
+ .irq_unmask = mc33978_irq_unmask,
+ .irq_bus_lock = mc33978_irq_bus_lock,
+ .irq_bus_sync_unlock = mc33978_irq_bus_sync_unlock,
+ .irq_set_type = mc33978_irq_set_type,
+ .irq_set_wake = mc33978_irq_set_wake,
+};
+
+static int mc33978_irq_map(struct irq_domain *d, unsigned int virq,
+ irq_hw_number_t hw)
+{
+ struct mc33978_mfd_priv *mc = d->host_data;
+
+ irq_set_chip_data(virq, mc);
+ irq_set_chip_and_handler(virq, &mc33978_irq_chip, handle_simple_irq);
+
+ irq_set_nested_thread(virq, 1);
+ irq_clear_status_flags(virq, IRQ_NOREQUEST | IRQ_NOPROBE);
+
+ return 0;
+}
+
+static int mc33978_irq_domain_alloc(struct irq_domain *domain,
+ unsigned int virq,
+ unsigned int nr_irqs, void *arg)
+{
+ struct mc33978_mfd_priv *mc = domain->host_data;
+ struct irq_fwspec *fwspec = arg;
+ irq_hw_number_t hwirq;
+ int i;
+
+ if (fwspec->param_count < 1)
+ return -EINVAL;
+
+ hwirq = fwspec->param[0];
+
+ for (i = 0; i < nr_irqs; i++) {
+ irq_domain_set_info(domain, virq + i, hwirq + i,
+ &mc33978_irq_chip, mc,
+ handle_simple_irq, NULL, NULL);
+ irq_set_nested_thread(virq + i, 1);
+ irq_clear_status_flags(virq + i, IRQ_NOREQUEST | IRQ_NOPROBE);
+ }
+
+ return 0;
+}
+
+static void mc33978_irq_domain_free(struct irq_domain *domain,
+ unsigned int virq,
+ unsigned int nr_irqs)
+{
+ int i;
+
+ for (i = 0; i < nr_irqs; i++)
+ irq_domain_reset_irq_data(irq_domain_get_irq_data(domain,
+ virq + i));
+}
+
+static const struct irq_domain_ops mc33978_irq_domain_ops = {
+ .map = mc33978_irq_map,
+ .alloc = mc33978_irq_domain_alloc,
+ .free = mc33978_irq_domain_free,
+ .xlate = irq_domain_xlate_twocell,
+};
+
+static void mc33978_irq_domain_remove(void *data)
+{
+ struct irq_domain *domain = data;
+
+ irq_domain_remove(domain);
+}
+
+static bool mc33978_handle_pin_changes(struct mc33978_mfd_priv *mc,
+ unsigned int pin_state)
+{
+ unsigned long fired_pins = 0;
+ u32 changed_pins;
+ u32 rise, fall;
+ int i;
+
+ changed_pins = pin_state ^ mc->cached_pin_state;
+ if (!changed_pins)
+ return false;
+
+ mc->cached_pin_state = pin_state;
+ changed_pins &= READ_ONCE(mc->cached_pin_mask);
+
+ if (!changed_pins)
+ return false;
+
+ rise = READ_ONCE(mc->irq_rise);
+ fall = READ_ONCE(mc->irq_fall);
+
+ fired_pins |= (changed_pins & pin_state) & rise;
+ fired_pins |= (changed_pins & ~pin_state) & fall;
+
+ for_each_set_bit(i, &fired_pins, MC33978_NUM_PINS) {
+ int virq = irq_find_mapping(mc->domain, i);
+
+ if (virq)
+ handle_nested_irq(virq);
+ }
+
+ return true;
+}
+
+static bool mc33978_handle_fault_condition(struct mc33978_mfd_priv *mc, u8 hw_flags)
+{
+ bool fault_active = READ_ONCE(mc->bus_fault_active);
+ bool cached_fault = READ_ONCE(mc->cached_fault_active);
+ bool changed = fault_active ^ cached_fault;
+ bool transient = !changed && (hw_flags & MC33978_HI_BYTE_STAT_FAULT);
+ u32 rise, fall;
+ int virq;
+ bool handled = false;
+
+ WRITE_ONCE(mc->cached_fault_active, fault_active);
+
+ if (!changed && !transient)
+ return false;
+
+ rise = READ_ONCE(mc->irq_rise);
+ fall = READ_ONCE(mc->irq_fall);
+
+ virq = irq_find_mapping(mc->domain, MC33978_HWIRQ_FAULT);
+ if (!virq)
+ return false;
+
+ if (transient) {
+ /* Transient pulse: trigger both edges if enabled */
+ if (rise & BIT(MC33978_HWIRQ_FAULT)) {
+ handle_nested_irq(virq);
+ handled = true;
+ }
+ if (fall & BIT(MC33978_HWIRQ_FAULT)) {
+ handle_nested_irq(virq);
+ handled = true;
+ }
+ } else {
+ /* Normal edge */
+ if (fault_active && (rise & BIT(MC33978_HWIRQ_FAULT))) {
+ handle_nested_irq(virq);
+ handled = true;
+ } else if (!fault_active && (fall & BIT(MC33978_HWIRQ_FAULT))) {
+ handle_nested_irq(virq);
+ handled = true;
+ }
+ }
+
+ return handled;
+}
+
+static bool mc33978_process_single_event(struct mc33978_mfd_priv *mc)
+{
+ unsigned int pin_state;
+ bool handled = false;
+ u8 hw_flags;
+ int ret;
+
+ /*
+ * Grab harvested_flags BEFORE reading the hardware. If the read itself
+ * or a concurrent SPI transfer harvests new flags, they will remain set
+ * in harvested_flags and correctly trigger another pass of the event loop.
+ *
+ * Note on Performance: This architecture intentionally forces a second
+ * (redundant) SPI read of READ_IN during almost every interrupt event.
+ * While SPI framework overhead (CS toggling, DMA setup, context switches)
+ * makes this 4-byte transfer relatively costly, it is mathematically
+ * necessary to guarantee no edge events are permanently lost when a
+ * concurrent regmap access races with the IRQ thread, due to the hardware's
+ * clear-on-read global INT_flg design.
+ */
+ hw_flags = atomic_xchg(&mc->harvested_flags, 0);
+
+ ret = regmap_read(mc->map, MC33978_REG_READ_IN, &pin_state);
+ if (ret)
+ return false;
+
+ if (mc33978_handle_pin_changes(mc, pin_state))
+ handled = true;
+
+ /*
+ * Pass hw_flags to handle_fault_condition so transient faults
+ * can be detected and processed properly.
+ */
+ if (mc33978_handle_fault_condition(mc, hw_flags))
+ handled = true;
+
+ if (hw_flags & MC33978_HI_BYTE_STAT_INT)
+ handled = true;
+
+ return handled;
+}
+
+static bool mc33978_handle_events(struct mc33978_mfd_priv *mc)
+{
+ bool handled = false;
+
+ guard(mutex)(&mc->event_lock);
+
+ do {
+ atomic_set(&mc->is_handling, 1);
+ /*
+ * Ensure the is_handling state is globally visible before we
+ * process the hardware events and re-evaluate harvested_flags.
+ */
+ smp_mb();
+
+ if (mc33978_process_single_event(mc))
+ handled = true;
+
+ atomic_set(&mc->is_handling, 0);
+ /*
+ * Ensure is_handling = 0 is globally visible before we check
+ * harvested_flags in the while loop, preventing a race where
+ * the harvester misses scheduling the workqueue.
+ */
+ smp_mb();
+
+ } while (atomic_read(&mc->harvested_flags) != 0);
+
+ return handled;
+}
+
+static irqreturn_t mc33978_irq_thread(int irq, void *data)
+{
+ return mc33978_handle_events(data) ? IRQ_HANDLED : IRQ_NONE;
+}
+
+static void mc33978_work_cancel(void *data)
+{
+ struct work_struct *work = data;
+
+ cancel_work_sync(work);
+}
+
+static int mc33978_irq_init(struct mc33978_mfd_priv *mc)
+{
+ struct device *dev = &mc->spi->dev;
+ int ret;
+
+ mutex_init(&mc->irq_lock);
+
+ /*
+ * Create IRQ domain with 23 interrupts:
+ * - hwirq 0-21: Pin change interrupts (22 pins)
+ * - hwirq 22: Fault interrupt (for hwmon driver)
+ */
+ mc->domain = irq_domain_add_linear(dev->of_node, MC33978_NUM_PINS + 1,
+ &mc33978_irq_domain_ops, mc);
+ if (!mc->domain)
+ return dev_err_probe(dev, -ENOMEM, "failed to create IRQ domain\n");
+
+ mc->domain->flags |= IRQ_DOMAIN_FLAG_HIERARCHY;
+
+ ret = devm_add_action_or_reset(dev, mc33978_irq_domain_remove,
+ mc->domain);
+ if (ret)
+ return ret;
+
+ /*
+ * Cancel the work before the IRQ domain is destroyed to prevent
+ * use-after-free during device teardown.
+ */
+ return devm_add_action_or_reset(dev, mc33978_work_cancel,
+ &mc->event_work);
+}
+
+static void mc33978_event_work(struct work_struct *work)
+{
+ struct mc33978_mfd_priv *mc =
+ container_of(work, struct mc33978_mfd_priv, event_work);
+
+ mc33978_handle_events(mc);
+}
+
+/**
+ * mc33978_harvest_status() - Collect status flags from SPI responses
+ * @mc: Device private data
+ * @status: Status bits (FAULT_STAT and INT_flg) from MISO frame
+ *
+ * Accumulates status flags harvested from SPI responses and schedules
+ * event processing if not already in progress. Called by the SPI
+ * read/write functions when status bits are detected in responses.
+ */
+static void mc33978_harvest_status(struct mc33978_mfd_priv *mc, u8 status)
+{
+ bool fault_active;
+
+ fault_active = !!(status & MC33978_HI_BYTE_STAT_FAULT);
+
+ /* Track the absolute latest physical state seen on the bus */
+ WRITE_ONCE(mc->bus_fault_active, fault_active);
+
+ /* If the bus state changed from what the IRQ thread last evaluated, wake it up */
+ if (fault_active != READ_ONCE(mc->cached_fault_active))
+ atomic_or(MC33978_HI_BYTE_STAT_FAULT, &mc->harvested_flags);
+
+ if (status & MC33978_HI_BYTE_STAT_INT)
+ atomic_or(MC33978_HI_BYTE_STAT_INT, &mc->harvested_flags);
+
+ /* Ensure harvested_flags is visible before reading is_handling */
+ smp_mb__after_atomic();
+
+ /*
+ * If the handler is not actively running and there are flags to process,
+ * schedule the background worker.
+ */
+ if (!atomic_read(&mc->is_handling) && atomic_read(&mc->harvested_flags))
+ schedule_work(&mc->event_work);
+}
+
+/**
+ * mc33978_prepare_messages() - Initialize the persistent SPI messages
+ * @mc: Device private data
+ *
+ * Hardware pipelining constraints:
+ * - Write (1 Frame): The device executes write commands immediately upon
+ * CS de-assertion. No fetch frame is required.
+ * - Read (2 Frames): The MISO response logically lags by one frame.
+ * Frame 1 transmits the read request and toggles CS to latch it.
+ * Frame 2 transmits a dummy CHECK command to fetch the actual payload.
+ */
+static void mc33978_prepare_messages(struct mc33978_mfd_priv *mc)
+{
+ /* --- Prepare Write Message (1 Frame) --- */
+ spi_message_init(&mc->msg_write);
+
+ mc->xfer_write.tx_buf = mc->tx_frame[MC33978_FRAME_REQ];
+ mc->xfer_write.rx_buf = mc->rx_frame[MC33978_FRAME_REQ];
+ mc->xfer_write.len = MC33978_FRAME_LEN;
+
+ spi_message_add_tail(&mc->xfer_write, &mc->msg_write);
+
+ /* --- Prepare Read Message (2 Frames) --- */
+ spi_message_init(&mc->msg_read);
+
+ /* Frame 1: Request */
+ mc->xfer_read[MC33978_FRAME_REQ].tx_buf =
+ mc->tx_frame[MC33978_FRAME_REQ];
+ mc->xfer_read[MC33978_FRAME_REQ].rx_buf =
+ mc->rx_frame[MC33978_FRAME_REQ];
+ mc->xfer_read[MC33978_FRAME_REQ].len = MC33978_FRAME_LEN;
+ mc->xfer_read[MC33978_FRAME_REQ].cs_change = 1; /* Latch command */
+
+ /* Frame 2: Fetch (Dummy CHECK) */
+ mc->xfer_read[MC33978_FRAME_PIPE].tx_buf =
+ mc->tx_frame[MC33978_FRAME_PIPE];
+ mc->xfer_read[MC33978_FRAME_PIPE].rx_buf =
+ mc->rx_frame[MC33978_FRAME_PIPE];
+ mc->xfer_read[MC33978_FRAME_PIPE].len = MC33978_FRAME_LEN;
+
+ /* Preload the dummy CHECK command statically */
+ mc->tx_frame[MC33978_FRAME_PIPE][MC33978_FRAME_CMD] = MC33978_REG_CHECK;
+
+ spi_message_add_tail(&mc->xfer_read[MC33978_FRAME_REQ], &mc->msg_read);
+ spi_message_add_tail(&mc->xfer_read[MC33978_FRAME_PIPE], &mc->msg_read);
+}
+
+/**
+ * mc33978_rx_decode() - Decode MISO response frame and extract status
+ * @rx_frame: Received SPI frame buffer (4 bytes)
+ * @val_buf: Output buffer for regmap (exactly 3 bytes, optional)
+ *
+ * Translates the 4-byte SPI response into a 3-byte regmap payload.
+ * Harvests the volatile INTflg and FAULT_STAT bits from the MSB.
+ *
+ * Return: Status bits if present, 0 otherwise.
+ */
+static u8 mc33978_rx_decode(const u8 *rx_frame, u8 *val_buf)
+{
+ u8 cmd = rx_frame[MC33978_FRAME_CMD] & ~MC33978_CMD_BYTE_WRITE;
+ bool has_status;
+ u8 status = 0;
+
+ switch (cmd) {
+ case MC33978_REG_CHECK:
+ case MC33978_REG_WET_SP:
+ case MC33978_REG_WET_SG0:
+ has_status = false;
+ break;
+ default:
+ has_status = true;
+ break;
+ }
+
+ if (has_status)
+ status = rx_frame[MC33978_FRAME_DATA_HI] &
+ MC33978_HI_BYTE_STATUS_MASK;
+
+ if (!val_buf)
+ return status;
+
+ memcpy(val_buf, &rx_frame[MC33978_FRAME_DATA_HI], MC33978_PAYLOAD_LEN);
+
+ if (has_status)
+ val_buf[MC33978_PAYLOAD_HI] &= MC33978_HI_BYTE_DATA_MASK;
+
+ return status;
+}
+
+static int mc33978_spi_write(void *ctx, const void *data, size_t count)
+{
+ struct mc33978_mfd_priv *mc = ctx;
+ u8 status;
+ int ret;
+
+ if (count != MC33978_FRAME_LEN)
+ return -EINVAL;
+
+ memcpy(mc->tx_frame[MC33978_FRAME_REQ], data, MC33978_FRAME_LEN);
+
+ ret = spi_sync(mc->spi, &mc->msg_write);
+ if (ret)
+ return ret;
+
+ status = mc33978_rx_decode(mc->rx_frame[MC33978_FRAME_REQ], NULL);
+ mc33978_harvest_status(mc, status);
+
+ return 0;
+}
+
+static int mc33978_spi_read(void *ctx, const void *reg_buf, size_t reg_size,
+ void *val_buf, size_t val_size)
+{
+ struct mc33978_mfd_priv *mc = ctx;
+ u8 status_req, status_pipe;
+ int ret;
+
+ if (reg_size != 1 || val_size != MC33978_PAYLOAD_LEN)
+ return -EINVAL;
+
+ memset(&mc->tx_frame[MC33978_FRAME_REQ][MC33978_FRAME_DATA_HI], 0,
+ MC33978_PAYLOAD_LEN);
+ mc->tx_frame[MC33978_FRAME_REQ][MC33978_FRAME_CMD] =
+ ((const u8 *)reg_buf)[0];
+
+ ret = spi_sync(mc->spi, &mc->msg_read);
+ if (ret)
+ return ret;
+
+ status_req = mc33978_rx_decode(mc->rx_frame[MC33978_FRAME_REQ], NULL);
+ status_pipe = mc33978_rx_decode(mc->rx_frame[MC33978_FRAME_PIPE],
+ val_buf);
+
+ mc33978_harvest_status(mc, status_req | status_pipe);
+
+ return 0;
+}
+
+static const struct regmap_bus mc33978_regmap_bus = {
+ .read = mc33978_spi_read,
+ .write = mc33978_spi_write,
+};
+
+static const struct regmap_range mc33978_volatile_range[] = {
+ regmap_reg_range(MC33978_REG_READ_IN, MC33978_REG_RESET),
+};
+
+static const struct regmap_access_table mc33978_volatile_table = {
+ .yes_ranges = mc33978_volatile_range,
+ .n_yes_ranges = ARRAY_SIZE(mc33978_volatile_range),
+};
+
+static const struct regmap_range mc33978_precious_range[] = {
+ regmap_reg_range(MC33978_REG_READ_IN, MC33978_REG_RESET),
+};
+
+static const struct regmap_access_table mc33978_precious_table = {
+ .yes_ranges = mc33978_precious_range,
+ .n_yes_ranges = ARRAY_SIZE(mc33978_precious_range),
+};
+
+/*
+ * NOTE: Need to fake REG_IRQ and REG_RESET as readable, so that regcache
+ * will NOT write to them on a cache sync. Sounds counterintuitive, but marking
+ * a reg as "precious" or "volatile" is the only way to avoid this, and that
+ * works only with readable regs.
+ */
+static const struct regmap_range mc33978_readable_range[] = {
+ regmap_reg_range(MC33978_REG_CHECK, MC33978_REG_WET_SG1),
+ regmap_reg_range(MC33978_REG_CWET_SP, MC33978_REG_WDEB_SG),
+ regmap_reg_range(MC33978_REG_AMUX_CTRL, MC33978_REG_RESET),
+};
+
+static const struct regmap_access_table mc33978_readable_table = {
+ .yes_ranges = mc33978_readable_range,
+ .n_yes_ranges = ARRAY_SIZE(mc33978_readable_range),
+};
+
+static const struct regmap_range mc33978_writable_range[] = {
+ regmap_reg_range(MC33978_REG_CONFIG, MC33978_REG_WET_SG1),
+ regmap_reg_range(MC33978_REG_CWET_SP, MC33978_REG_AMUX_CTRL),
+ regmap_reg_range(MC33978_REG_IRQ, MC33978_REG_RESET),
+};
+
+static const struct regmap_access_table mc33978_writable_table = {
+ .yes_ranges = mc33978_writable_range,
+ .n_yes_ranges = ARRAY_SIZE(mc33978_writable_range),
+};
+
+static const struct regmap_config mc33978_regmap_config = {
+ .name = MC33978_DRV_NAME,
+ .reg_bits = 8,
+ .val_bits = 24,
+ .reg_stride = 2,
+ .write_flag_mask = MC33978_CMD_BYTE_WRITE,
+ .reg_format_endian = REGMAP_ENDIAN_BIG,
+ .val_format_endian = REGMAP_ENDIAN_BIG,
+ .use_single_read = true,
+ .use_single_write = true,
+ .volatile_table = &mc33978_volatile_table,
+ .precious_table = &mc33978_precious_table,
+ .rd_table = &mc33978_readable_table,
+ .wr_table = &mc33978_writable_table,
+ .cache_type = REGCACHE_MAPLE,
+ .max_register = MC33978_REG_RESET,
+};
+
+static int mc33978_power_on(struct mc33978_mfd_priv *mc)
+{
+ struct device *dev = &mc->spi->dev;
+ int ret;
+
+ ret = regulator_enable(mc->vddq);
+ if (ret)
+ return dev_err_probe(dev, ret, "failed to enable VDDQ supply\n");
+
+ ret = regulator_enable(mc->vbatp);
+ if (ret) {
+ regulator_disable(mc->vddq);
+ return dev_err_probe(dev, ret, "failed to enable VBATP supply\n");
+ }
+
+ return 0;
+}
+
+static void mc33978_power_off(void *data)
+{
+ struct mc33978_mfd_priv *mc = data;
+
+ regulator_disable(mc->vbatp);
+ regulator_disable(mc->vddq);
+}
+
+/**
+ * mc33978_check_device() - Verify SPI communication with device
+ * @mc: Device context
+ *
+ * Reads the CHECK register which should return a fixed signature (0x123456).
+ * This verifies that SPI communication is working correctly.
+ *
+ * Return: 0 on success, -ENODEV if signature doesn't match
+ */
+static int mc33978_check_device(struct mc33978_mfd_priv *mc)
+{
+ struct device *dev = &mc->spi->dev;
+ unsigned int check;
+ int ret;
+
+ ret = regmap_read(mc->map, MC33978_REG_CHECK, &check);
+ if (ret)
+ return ret;
+
+ if (check != MC33978_CHECK_SIGNATURE)
+ return dev_err_probe(dev, -ENODEV,
+ "SPI check failed. Expected: 0x%06x, got: 0x%06x\n",
+ MC33978_CHECK_SIGNATURE, check);
+
+ return 0;
+}
+
+static const struct resource mc33978_hwmon_resources[] = {
+ DEFINE_RES_IRQ(MC33978_HWIRQ_FAULT),
+};
+
+static const struct mfd_cell mc33978_cells[] = {
+ { .name = "mc33978-pinctrl" },
+ {
+ .name = "mc33978-hwmon",
+ .resources = mc33978_hwmon_resources,
+ .num_resources = ARRAY_SIZE(mc33978_hwmon_resources),
+ },
+ { .name = "mc33978-mux" },
+};
+
+static const struct mfd_cell mc34978_cells[] = {
+ { .name = "mc34978-pinctrl" },
+ {
+ .name = "mc34978-hwmon",
+ .resources = mc33978_hwmon_resources,
+ .num_resources = ARRAY_SIZE(mc33978_hwmon_resources),
+ },
+ { .name = "mc34978-mux" },
+};
+
+static const struct mc33978_data mc33978_match_data = {
+ .cells = mc33978_cells,
+ .num_cells = ARRAY_SIZE(mc33978_cells),
+};
+
+static const struct mc33978_data mc34978_match_data = {
+ .cells = mc34978_cells,
+ .num_cells = ARRAY_SIZE(mc34978_cells),
+};
+
+static int mc33978_probe(struct spi_device *spi)
+{
+ const struct mc33978_data *match_data;
+ struct device *dev = &spi->dev;
+ struct mc33978_mfd_priv *mc;
+ int ret;
+
+ match_data = spi_get_device_match_data(spi);
+ if (!match_data)
+ return dev_err_probe(dev, -ENODEV, "no device match data found\n");
+
+ mc = devm_kzalloc(dev, sizeof(*mc), GFP_KERNEL);
+ if (!mc)
+ return -ENOMEM;
+
+ mc->spi = spi;
+ spi_set_drvdata(spi, mc);
+
+ mc->vddq = devm_regulator_get(dev, "vddq");
+ if (IS_ERR(mc->vddq))
+ return dev_err_probe(dev, PTR_ERR(mc->vddq),
+ "failed to get VDDQ regulator\n");
+
+ mc->vbatp = devm_regulator_get(dev, "vbatp");
+ if (IS_ERR(mc->vbatp))
+ return dev_err_probe(dev, PTR_ERR(mc->vbatp),
+ "failed to get VBATP regulator\n");
+
+ ret = mc33978_power_on(mc);
+ if (ret)
+ return ret;
+
+ ret = devm_add_action_or_reset(dev, mc33978_power_off, mc);
+ if (ret)
+ return ret;
+
+ mutex_init(&mc->event_lock);
+
+ INIT_WORK(&mc->event_work, mc33978_event_work);
+
+ atomic_set(&mc->harvested_flags, 0);
+ atomic_set(&mc->is_handling, 0);
+
+ mc33978_prepare_messages(mc);
+
+ mc->map = devm_regmap_init(dev, &mc33978_regmap_bus, mc,
+ &mc33978_regmap_config);
+ if (IS_ERR(mc->map))
+ return dev_err_probe(dev, PTR_ERR(mc->map), "can't init regmap\n");
+
+ ret = mc33978_check_device(mc);
+ if (ret)
+ return dev_err_probe(dev, ret, "can't use SPI bus\n");
+
+ /* Initialize IRQ domain early so background worker can safely use it */
+ ret = mc33978_irq_init(mc);
+ if (ret)
+ return ret;
+
+ /* Disable interrupts to prevent storms during priming */
+ ret = regmap_write(mc->map, MC33978_REG_IE_SP, 0);
+ if (ret)
+ return ret;
+
+ ret = regmap_write(mc->map, MC33978_REG_IE_SG, 0);
+ if (ret)
+ return ret;
+
+ /* Prime the cached pin state under lock to prevent spurious events */
+ mutex_lock(&mc->event_lock);
+ ret = regmap_read(mc->map, MC33978_REG_READ_IN, &mc->cached_pin_state);
+ mutex_unlock(&mc->event_lock);
+ if (ret)
+ return dev_err_probe(dev, ret, "failed to read initial pin state\n");
+
+ if (mc->spi->irq <= 0)
+ return dev_err_probe(dev, -EINVAL, "no valid IRQ provided for INT_B pin\n");
+
+ ret = devm_request_threaded_irq(dev, mc->spi->irq, NULL,
+ mc33978_irq_thread,
+ IRQF_ONESHOT | IRQF_SHARED,
+ dev_name(dev), mc);
+ if (ret)
+ return dev_err_probe(dev, ret, "failed to request IRQ\n");
+
+ ret = devm_mfd_add_devices(dev, PLATFORM_DEVID_NONE,
+ match_data->cells, match_data->num_cells,
+ NULL, 0, mc->domain);
+ if (ret)
+ return dev_err_probe(dev, ret, "failed to add MFD child devices\n");
+
+ return 0;
+}
+
+static const struct of_device_id mc33978_of_match[] = {
+ { .compatible = "nxp,mc33978", .data = &mc33978_match_data },
+ { .compatible = "nxp,mc34978", .data = &mc34978_match_data },
+ { }
+};
+MODULE_DEVICE_TABLE(of, mc33978_of_match);
+
+static const struct spi_device_id mc33978_spi_id[] = {
+ { "mc33978", (kernel_ulong_t)&mc33978_match_data },
+ { "mc34978", (kernel_ulong_t)&mc34978_match_data },
+ { }
+};
+MODULE_DEVICE_TABLE(spi, mc33978_spi_id);
+
+static struct spi_driver mc33978_driver = {
+ .driver = {
+ .name = MC33978_DRV_NAME,
+ .of_match_table = mc33978_of_match,
+ },
+ .probe = mc33978_probe,
+ .id_table = mc33978_spi_id,
+};
+module_spi_driver(mc33978_driver);
+
+MODULE_AUTHOR("David Jander <david@protonic.nl>");
+MODULE_DESCRIPTION("NXP MC33978/MC34978 MFD core driver");
+MODULE_LICENSE("GPL");
diff --git a/include/linux/mfd/mc33978.h b/include/linux/mfd/mc33978.h
new file mode 100644
index 000000000000..e8dec678e5a4
--- /dev/null
+++ b/include/linux/mfd/mc33978.h
@@ -0,0 +1,92 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * Copyright (C) 2024 David Jander <david@protonic.nl>, Protonic Holland
+ * Copyright (C) 2026 Oleksij Rempel <kernel@pengutronix.de>, Pengutronix
+ *
+ * MC34978/MC33978 Multiple Switch Detection Interface - Shared Definitions
+ */
+
+#ifndef _LINUX_MFD_MC33978_H
+#define _LINUX_MFD_MC33978_H
+
+#include <linux/bits.h>
+
+/* Register Map - All addresses are base command bytes (R/W bit = 0) */
+#define MC33978_REG_CHECK 0x00 /* SPI communication check */
+#define MC33978_REG_CONFIG 0x02 /* Device configuration */
+#define MC33978_REG_TRI_SP 0x04 /* Tri-state enable SP */
+#define MC33978_REG_TRI_SG 0x06 /* Tri-state enable SG */
+#define MC33978_REG_WET_SP 0x08 /* Wetting current level SP */
+#define MC33978_REG_WET_SG0 0x0a /* Wetting current level SG0 (SG7-SG0) */
+#define MC33978_REG_WET_SG1 0x0c /* Wetting current level SG1 (SG13-SG8) */
+#define MC33978_REG_CWET_SP 0x16 /* Continuous wetting current SP */
+#define MC33978_REG_CWET_SG 0x18 /* Continuous wetting current SG */
+#define MC33978_REG_IE_SP 0x1a /* Interrupt enable SP */
+#define MC33978_REG_IE_SG 0x1c /* Interrupt enable SG */
+#define MC33978_REG_LPM_CONFIG 0x1e /* Low-power mode configuration */
+#define MC33978_REG_WAKE_SP 0x20 /* Wake-up enable SP */
+#define MC33978_REG_WAKE_SG 0x22 /* Wake-up enable SG */
+#define MC33978_REG_COMP_SP 0x24 /* Comparator only mode SP */
+#define MC33978_REG_COMP_SG 0x26 /* Comparator only mode SG */
+#define MC33978_REG_LPM_VT_SP 0x28 /* LPM voltage threshold SP */
+#define MC33978_REG_LPM_VT_SG 0x2a /* LPM voltage threshold SG */
+#define MC33978_REG_IP_SP 0x2c /* Polling current SP */
+#define MC33978_REG_IP_SG 0x2e /* Polling current SG */
+#define MC33978_REG_SPOLL_SP 0x30 /* Slow polling SP */
+#define MC33978_REG_SPOLL_SG 0x32 /* Slow polling SG */
+#define MC33978_REG_WDEB_SP 0x34 /* Wake-up debounce SP */
+#define MC33978_REG_WDEB_SG 0x36 /* Wake-up debounce SG */
+#define MC33978_REG_ENTER_LPM 0x38 /* Enter low-power mode (write-only) */
+#define MC33978_REG_AMUX_CTRL 0x3a /* AMUX control */
+#define MC33978_REG_READ_IN 0x3e /* Read switch status (READ_SW in datasheet) */
+#define MC33978_REG_FAULT 0x42 /* Fault status register */
+#define MC33978_REG_IRQ 0x46 /* Interrupt request (write-only) */
+#define MC33978_REG_RESET 0x48 /* Reset (write-only) */
+
+/*
+ * FAULT Register (0x42) bit definitions
+ * Reading this register clears most fault flags except persistent conditions
+ */
+#define MC33978_FAULT_SPI_ERROR BIT(10) /* SPI communication error */
+#define MC33978_FAULT_HASH BIT(9) /* SPI register hash mismatch */
+#define MC33978_FAULT_UV BIT(7) /* VBATP undervoltage */
+#define MC33978_FAULT_OV BIT(6) /* VBATP overvoltage */
+#define MC33978_FAULT_TEMP_WARN BIT(5) /* Temperature warning threshold */
+#define MC33978_FAULT_OT BIT(4) /* Over-temperature */
+#define MC33978_FAULT_INTB_WAKE BIT(3) /* Woken by INT_B pin */
+#define MC33978_FAULT_WAKEB_WAKE BIT(2) /* Woken by WAKE_B pin */
+#define MC33978_FAULT_SPI_WAKE BIT(1) /* Woken by SPI message */
+#define MC33978_FAULT_POR BIT(0) /* Power-on reset occurred */
+
+/* Critical faults that need immediate attention */
+#define MC33978_FAULT_CRITICAL (MC33978_FAULT_UV | \
+ MC33978_FAULT_OV | \
+ MC33978_FAULT_OT)
+
+/* Bits relevant as hwmon alarms; excludes wake/reset/SPI status bits */
+#define MC33978_FAULT_ALARM_MASK (MC33978_FAULT_UV | \
+ MC33978_FAULT_OV | \
+ MC33978_FAULT_TEMP_WARN | \
+ MC33978_FAULT_OT)
+
+#define MC33978_NUM_PINS 22
+
+/*
+ * Virtual IRQ number for fault handling.
+ * Using hwirq 22 (beyond the 22 pin IRQs 0-21).
+ */
+#define MC33978_HWIRQ_FAULT 22
+
+/*
+ * AMUX channel definitions
+ * The AMUX can route one of 24 signals to the external AMUX pin
+ */
+#define MC33978_AMUX_CH_SG0 0 /* Switch-to-Ground inputs 0-13 */
+#define MC33978_AMUX_CH_SG13 13
+#define MC33978_AMUX_CH_SP0 14 /* Programmable switch inputs 0-7 */
+#define MC33978_AMUX_CH_SP7 21
+#define MC33978_AMUX_CH_TEMP 22 /* Internal temperature diode */
+#define MC33978_AMUX_CH_VBATP 23 /* Battery voltage sense */
+#define MC33978_NUM_AMUX_CH 24 /* Total number of AMUX channels */
+
+#endif /* _LINUX_MFD_MC33978_H */
--
2.47.3
^ permalink raw reply related
* [PATCH v8 4/6] pinctrl: add NXP MC33978/MC34978 pinctrl driver
From: Oleksij Rempel @ 2026-03-29 9:05 UTC (permalink / raw)
To: Guenter Roeck, Rob Herring, Krzysztof Kozlowski, Conor Dooley,
Lee Jones, Peter Rosin, Linus Walleij
Cc: David Jander, Oleksij Rempel, kernel, linux-kernel, devicetree,
linux-hwmon, linux-gpio
In-Reply-To: <20260329090601.532477-1-o.rempel@pengutronix.de>
From: David Jander <david@protonic.nl>
Add pin control and GPIO driver for the NXP MC33978/MC34978 Multiple
Switch Detection Interface (MSDI) devices.
This driver exposes the 22 mechanical switch detection inputs (14
Switch-to-Ground, 8 Programmable) as standard GPIOs.
Key features implemented:
- GPIO read/write: Translates physical switch states (open/closed)
to logical GPIO levels based on the configured switch topology
(Switch-to-Ground vs. Switch-to-Battery).
- Emulated Output: Allows setting pins "high" or "low" by manipulating
the tri-state registers and hardware pull topologies.
- Interrupt routing: Proxies GPIO interrupt requests to the irq_domain
managed by the parent MFD core driver via a hierarchical irq_chip.
Signed-off-by: David Jander <david@protonic.nl>
Co-developed-by: Oleksij Rempel <o.rempel@pengutronix.de>
Signed-off-by: Oleksij Rempel <o.rempel@pengutronix.de>
Reviewed-by: Linus Walleij <linusw@kernel.org>
---
changes v8:
- Fix comment documentation to state the driver implements a hierarchical
irq_chip instead of proxying .to_irq().
- Add missing <linux/irqdomain.h> include.
- Add .irq_set_wake = irq_chip_set_wake_parent to the gpio_irq_chip to
properly proxy wake-up configuration to the parent domain.
- Replace irq_find_host() with irq_find_matching_fwnode() during probe
to support parent domain lookup on non-OF platforms.
changes v7:
- Refactor I/O state reading and tri-state updates for SG/SB topologies
- Fix open-drain and open-source pinconf emulation
- Make direction_input a no-op to prevent overriding pinctrl bias
- Add defensive wrappers for IRQ proxying to prevent NULL pointer panics
- Add missing mutex guards to pinconf and get operations
- Convert generic internal variables to u32 and add lockdep assertions
changes v6:
- no changes
changes v5:
- no changes
changes v4:
- add Reviewed-by: Linus Walleij ...
- Replace the of_device_id match table with a platform_device_id table
- Add device_set_node(dev, dev_fwnode(dev->parent)) during probe
- Remove the check for a missing dev->of_node
changes v3:
- replace manual mutex_lock()/mutex_unlock() paths with guard(mutex)
- Unify error checking style by replacing if (ret < 0) with if (ret)
- Migrate from a custom .to_irq callback to a hierarchical gpio_irq_chip
- Implement .irq_bus_lock and .irq_bus_sync_unlock proxies to properly
cascade SPI bus lock operations to the parent MFD domain
- Set girq->handler to handle_simple_irq
changes v2:
- Translate all remaining German comments to English.
- Remove unnecessary #ifdef CONFIG_OF wrappers around dt_node_to_map.
- Add detailed comments to mc33978_get() and mc33978_get_multiple() explaining
the hardware comparator logic (1 = closed, 0 = open) and justifying the
bitwise inversion required to report actual physical voltage levels.
- Add comments to the .set() and .set_config() callbacks explaining why
gpiolib's standard open-drain emulation (switching to input mode) fails on
this hardware due to active wetting currents, and why tri-state isolation is
mandatory.
- Add a comment to mc33978_gpio_to_irq() explaining why it must act as a
proxy to the parent MFD's irq_domain (shared physical INT_B line with hwmon).
- Drop dummy pin group callbacks (get_groups_count, etc.). This relies on a
preparatory patch in this series making these callbacks optional in the core.
- Fix debugfs 'pinconf-pins' read errors by correctly returning -ENOTSUPP
instead of -EOPNOTSUPP for unsupported generic configurations.
- Fix empty 'gpio-ranges' and missing debugfs labels by explicitly calling
gpiochip_add_pin_range() during probe.
- Eliminate "magic" bitwise math in the wetting current configuration by
introducing a static lookup array (mc33978_wet_mA).
- Resolve checkpatch.pl strict warnings regarding macro argument reuse by
converting MC33978_SPSG, MC33978_PINSHIFT, MC33978_WREG, and MC33978_WSHIFT
to static inline functions.
- Remove artifacts from previous interrupt handling implementations.
- Address minor formatting and whitespace nits.
---
drivers/pinctrl/Kconfig | 14 +
drivers/pinctrl/Makefile | 1 +
drivers/pinctrl/pinctrl-mc33978.c | 839 ++++++++++++++++++++++++++++++
3 files changed, 854 insertions(+)
create mode 100644 drivers/pinctrl/pinctrl-mc33978.c
diff --git a/drivers/pinctrl/Kconfig b/drivers/pinctrl/Kconfig
index afecd9407f53..c315656c0fe5 100644
--- a/drivers/pinctrl/Kconfig
+++ b/drivers/pinctrl/Kconfig
@@ -388,6 +388,20 @@ config PINCTRL_MAX77620
function in alternate mode. This driver also configure push-pull,
open drain, FPS slots etc.
+config PINCTRL_MC33978
+ tristate "MC33978/MC34978 industrial input controller support"
+ depends on MFD_MC33978
+ select GPIOLIB
+ select GENERIC_PINCONF
+ help
+ Say Y here to enable support for NXP MC33978/MC34978 Multiple
+ Switch Detection Interface (MSDI) devices. This driver provides
+ pinctrl and GPIO interfaces for the 22 mechanical switch inputs
+ (14 Switch-to-Ground, 8 Programmable).
+
+ It allows reading switch states, configuring hardware pull
+ topologies, and handling interrupts for state changes.
+
config PINCTRL_MCP23S08_I2C
tristate
select REGMAP_I2C
diff --git a/drivers/pinctrl/Makefile b/drivers/pinctrl/Makefile
index f7d5d5f76d0c..afb58fb5a197 100644
--- a/drivers/pinctrl/Makefile
+++ b/drivers/pinctrl/Makefile
@@ -40,6 +40,7 @@ obj-$(CONFIG_PINCTRL_XWAY) += pinctrl-xway.o
obj-$(CONFIG_PINCTRL_LPC18XX) += pinctrl-lpc18xx.o
obj-$(CONFIG_PINCTRL_MAX7360) += pinctrl-max7360.o
obj-$(CONFIG_PINCTRL_MAX77620) += pinctrl-max77620.o
+obj-$(CONFIG_PINCTRL_MC33978) += pinctrl-mc33978.o
obj-$(CONFIG_PINCTRL_MCP23S08_I2C) += pinctrl-mcp23s08_i2c.o
obj-$(CONFIG_PINCTRL_MCP23S08_SPI) += pinctrl-mcp23s08_spi.o
obj-$(CONFIG_PINCTRL_MCP23S08) += pinctrl-mcp23s08.o
diff --git a/drivers/pinctrl/pinctrl-mc33978.c b/drivers/pinctrl/pinctrl-mc33978.c
new file mode 100644
index 000000000000..b53718e98ef2
--- /dev/null
+++ b/drivers/pinctrl/pinctrl-mc33978.c
@@ -0,0 +1,839 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (C) 2024 David Jander <david@protonic.nl>, Protonic Holland
+ * Copyright (C) 2026 Oleksij Rempel <kernel@pengutronix.de>, Pengutronix
+ *
+ * MC33978/MC34978 Multiple Switch Detection Interface - Pinctrl/GPIO Driver
+ *
+ * Provides GPIO and pinctrl interfaces for the 22 switch detection inputs.
+ * Handles digital input reading and wetting current configuration. Analog AMUX
+ * functionality is handled by a separate mux driver.
+ *
+ * GPIO Mapping:
+ * - GPIO 0-13: SG0-SG13 (Switch-to-Ground inputs)
+ * - GPIO 14-21: SP0-SP7 (Programmable: Switch-to-Ground or Switch-to-Battery)
+ * This is dictated by the READ_IN register where bits [21:14] = SP[7:0]
+ * and bits [13:0] = SG[13:0].
+ *
+ * Register Organization:
+ * Configuration registers are generally paired. The _SP register at offset N
+ * controls SP0-SP7, and the _SG register at offset N+2 controls SG0-SG13.
+ *
+ * Wetting Currents vs. Pull Resistors:
+ * The hardware physically lacks traditional passive pull-up or pull-down
+ * resistors. Instead, it uses active, controllable current regulators
+ * (wetting currents) to detect switch states and clean mechanical contacts.
+ * - Because these are active current sources, specifying an ohmic value for
+ * pull-up/down biases is physically invalid. The driver ignores ohm arguments.
+ * - 8 selectable current values: 2, 6, 8, 10, 12, 14, 16, 20 mA.
+ * - Exposed via the pinconf PIN_CONFIG_DRIVE_STRENGTH parameter (in mA).
+ *
+ * Emulated Outputs:
+ * The hardware lacks traditional push-pull output drivers; it is strictly an
+ * input device. "Outputs" are simulated by toggling the wetting currents and
+ * physically isolating the pins via hardware tri-state registers. Consequently,
+ * consumers MUST flag outputs with GPIO_OPEN_DRAIN or GPIO_OPEN_SOURCE in
+ * the Device Tree.
+ *
+ * Input Detection Mechanics:
+ * This input mechanism relies on the active current regulators rather than
+ * passive hard resistors. For a Switch-to-Ground (SG) pin, the chip sources
+ * a constant current. When the switch is open, the pin voltage floats up to
+ * the battery voltage. When the switch closes, it creates a path to ground;
+ * because the current is strictly regulated, the pin voltage drops sharply
+ * below the internal 4.0V comparator threshold.
+ * * The hardware evaluates this and reports an abstract "contact status"
+ * (1 = closed, 0 = open). For SG pins, a closed switch (~0V) reports as '1'.
+ * To align with gpiolib expectations where ~0V equals a physical logical '0',
+ * this driver explicitly inverts the hardware status for all SG-configured
+ * pins before reporting them.
+ *
+ * Interrupts:
+ * The physical INT_B line and threaded IRQ domain are managed centrally by
+ * the parent MFD core. This driver implements a hierarchical irq_chip
+ * to proxy masking/unmasking and configuration to the parent domain.
+ *
+ * Written by David Jander <david@protonic.nl>
+ *
+ * Datasheet:
+ * https://www.nxp.com/docs/en/data-sheet/MC33978.pdf
+ */
+
+#include <linux/cleanup.h>
+#include <linux/device.h>
+#include <linux/gpio/driver.h>
+#include <linux/interrupt.h>
+#include <linux/irq.h>
+#include <linux/irqdomain.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/mutex.h>
+#include <linux/pinctrl/pinconf-generic.h>
+#include <linux/pinctrl/pinconf.h>
+#include <linux/pinctrl/pinctrl.h>
+#include <linux/platform_device.h>
+#include <linux/regmap.h>
+#include <linux/seq_file.h>
+
+#include <linux/mfd/mc33978.h>
+
+#define MC33978_NGPIO 22
+
+/*
+ * Input numbering is dictated by bit-order of the input register:
+ * Inputs 0-13 -> SG0-SG13
+ * Inputs 14-21 -> SP0-SP7
+ */
+#define MC33978_NUM_SG 14
+#define MC33978_SP_MASK GENMASK(MC33978_NGPIO - 1, MC33978_NUM_SG)
+#define MC33978_SG_MASK GENMASK(MC33978_NUM_SG - 1, 0)
+#define MC33978_SG_SHIFT 0
+#define MC33978_SP_SHIFT MC33978_NUM_SG
+
+#define MC33978_TRISTATE 0
+#define MC33978_PU 1
+#define MC33978_PD 2
+
+struct mc33978_pinctrl {
+ struct device *dev;
+ struct regmap *regmap;
+ int irq;
+
+ struct irq_domain *domain;
+
+ struct gpio_chip chip;
+ struct pinctrl_dev *pctldev;
+ struct pinctrl_desc pinctrl_desc;
+
+ /*
+ * Protects multi-register hardware sequences in .set() and atomic
+ * READ_IN + CONFIG reads in .get()
+ */
+ struct mutex lock;
+};
+
+static const struct pinctrl_pin_desc mc33978_pins[] = {
+ PINCTRL_PIN(0, "sg0"),
+ PINCTRL_PIN(1, "sg1"),
+ PINCTRL_PIN(2, "sg2"),
+ PINCTRL_PIN(3, "sg3"),
+ PINCTRL_PIN(4, "sg4"),
+ PINCTRL_PIN(5, "sg5"),
+ PINCTRL_PIN(6, "sg6"),
+ PINCTRL_PIN(7, "sg7"),
+ PINCTRL_PIN(8, "sg8"),
+ PINCTRL_PIN(9, "sg9"),
+ PINCTRL_PIN(10, "sg10"),
+ PINCTRL_PIN(11, "sg11"),
+ PINCTRL_PIN(12, "sg12"),
+ PINCTRL_PIN(13, "sg13"),
+ PINCTRL_PIN(14, "sp0"),
+ PINCTRL_PIN(15, "sp1"),
+ PINCTRL_PIN(16, "sp2"),
+ PINCTRL_PIN(17, "sp3"),
+ PINCTRL_PIN(18, "sp4"),
+ PINCTRL_PIN(19, "sp5"),
+ PINCTRL_PIN(20, "sp6"),
+ PINCTRL_PIN(21, "sp7"),
+};
+
+static inline bool mc33978_is_sp(unsigned int pin)
+{
+ return pin >= MC33978_NUM_SG;
+}
+
+/* Choose register offset for _SG/_SP registers. reg is always the _SP addr. */
+static inline u8 mc33978_spsg(u8 reg, unsigned int pin)
+{
+ return mc33978_is_sp(pin) ? reg : reg + 2;
+}
+
+/* Get the bit index into the corresponding register */
+static inline unsigned int mc33978_pinshift(unsigned int pin)
+{
+ return mc33978_is_sp(pin) ? pin - MC33978_NUM_SG : pin;
+}
+
+#define MC33978_PINMASK(pin) BIT(mc33978_pinshift(pin))
+
+/*
+ * Wetting current registers: 3 in total, each pin uses a 3-bit field,
+ * 8 pins per register, except for the last one.
+ */
+static inline u8 mc33978_wreg(u8 reg, unsigned int pin)
+{
+ return reg + (mc33978_is_sp(pin) ? 0 : 2 + 2 * (pin / 8));
+}
+
+static inline unsigned int mc33978_wshift(unsigned int pin)
+{
+ return mc33978_is_sp(pin) ? 3 * (pin - MC33978_NUM_SG) : 3 * (pin % 8);
+}
+
+#define MC33978_WMASK(pin) (7 << mc33978_wshift(pin))
+
+static int mc33978_read(struct mc33978_pinctrl *mpc, u8 reg, u32 *val)
+{
+ int ret;
+
+ ret = regmap_read(mpc->regmap, reg, val);
+ if (ret)
+ dev_err_ratelimited(mpc->dev, "Regmap read error %d at reg: %02x.\n",
+ ret, reg);
+ return ret;
+}
+
+static int mc33978_update_bits(struct mc33978_pinctrl *mpc, u8 reg, u32 mask,
+ u32 val)
+{
+ int ret;
+
+ ret = regmap_update_bits(mpc->regmap, reg, mask, val);
+ if (ret)
+ dev_err_ratelimited(mpc->dev, "Regmap update bits error %d at reg: %02x.\n",
+ ret, reg);
+ return ret;
+}
+
+static const struct pinctrl_ops mc33978_pinctrl_ops = {
+ .dt_node_to_map = pinconf_generic_dt_node_to_map_pin,
+ .dt_free_map = pinconf_generic_dt_free_map,
+};
+
+static int mc33978_get_pull(struct mc33978_pinctrl *mpc, unsigned int pin, u32 *val)
+{
+ u32 data;
+ int ret;
+
+ lockdep_assert_held(&mpc->lock);
+
+ ret = mc33978_read(mpc, mc33978_spsg(MC33978_REG_TRI_SP, pin), &data);
+ if (ret)
+ return ret;
+
+ /* Is the pin tri-stated? */
+ if (data & MC33978_PINMASK(pin)) {
+ *val = MC33978_TRISTATE;
+ return 0;
+ }
+
+ /* Pins 0..13 only support pull-up */
+ if (!mc33978_is_sp(pin)) {
+ *val = MC33978_PU;
+ return 0;
+ }
+
+ /* Check pin pull direction for pins 14..21 */
+ ret = mc33978_read(mpc, MC33978_REG_CONFIG, &data);
+ if (ret)
+ return ret;
+
+ if (data & MC33978_PINMASK(pin))
+ *val = MC33978_PD;
+ else
+ *val = MC33978_PU;
+
+ return 0;
+}
+
+static int mc33978_set_pull(struct mc33978_pinctrl *mpc, unsigned int pin, int val)
+{
+ u32 mask = MC33978_PINMASK(pin);
+ int ret;
+
+ lockdep_assert_held(&mpc->lock);
+
+ /* SG pins physically lack pull-downs current sources */
+ if (val == MC33978_PD && !mc33978_is_sp(pin))
+ return -EINVAL;
+
+ /* Configure direction (Exclusively for SP pins) */
+ if (mc33978_is_sp(pin) && val != MC33978_TRISTATE) {
+ ret = mc33978_update_bits(mpc, MC33978_REG_CONFIG, mask,
+ (val == MC33978_PD) ? mask : 0);
+ if (ret)
+ return ret;
+ }
+
+ /* Enable current source or set to tri-state */
+ return mc33978_update_bits(mpc, mc33978_spsg(MC33978_REG_TRI_SP, pin),
+ mask,
+ (val == MC33978_TRISTATE) ? mask : 0);
+}
+
+static const unsigned int mc33978_wet_mA[] = { 2, 6, 8, 10, 12, 14, 16, 20 };
+
+static int mc33978_set_ds(struct mc33978_pinctrl *mpc, unsigned int pin,
+ u32 val)
+{
+ int i;
+
+ for (i = 0; i < ARRAY_SIZE(mc33978_wet_mA); i++) {
+ if (val == mc33978_wet_mA[i]) {
+ return mc33978_update_bits(mpc,
+ mc33978_wreg(MC33978_REG_WET_SP, pin),
+ MC33978_WMASK(pin),
+ i << mc33978_wshift(pin));
+ }
+ }
+
+ return -EINVAL;
+}
+
+static int mc33978_get_ds(struct mc33978_pinctrl *mpc, unsigned int pin,
+ u32 *val)
+{
+ u32 data;
+ int ret;
+
+ ret = mc33978_read(mpc, mc33978_wreg(MC33978_REG_WET_SP, pin), &data);
+ if (ret)
+ return ret;
+
+ data &= MC33978_WMASK(pin);
+ data >>= mc33978_wshift(pin);
+
+ if (data >= ARRAY_SIZE(mc33978_wet_mA))
+ return -EINVAL;
+
+ *val = mc33978_wet_mA[data];
+
+ return 0;
+}
+
+static int mc33978_pinconf_get(struct pinctrl_dev *pctldev, unsigned int pin,
+ unsigned long *config)
+{
+ struct mc33978_pinctrl *mpc = pinctrl_dev_get_drvdata(pctldev);
+ enum pin_config_param param = pinconf_to_config_param(*config);
+ u32 arg;
+ u32 data;
+ int ret;
+
+ guard(mutex)(&mpc->lock);
+
+ switch (param) {
+ case PIN_CONFIG_BIAS_PULL_UP:
+ ret = mc33978_get_pull(mpc, pin, &data);
+ if (ret)
+ return ret;
+ if (data != MC33978_PU)
+ return -EINVAL;
+ arg = 1;
+ break;
+ case PIN_CONFIG_BIAS_PULL_DOWN:
+ ret = mc33978_get_pull(mpc, pin, &data);
+ if (ret)
+ return ret;
+ if (data != MC33978_PD)
+ return -EINVAL;
+ arg = 1;
+ break;
+ case PIN_CONFIG_DRIVE_OPEN_DRAIN:
+ if (!mc33978_is_sp(pin))
+ return -EINVAL;
+
+ ret = mc33978_read(mpc, MC33978_REG_CONFIG, &data);
+ if (ret)
+ return ret;
+
+ if (!(data & MC33978_PINMASK(pin)))
+ return -EINVAL;
+ arg = 1;
+ break;
+ case PIN_CONFIG_DRIVE_OPEN_SOURCE:
+ if (mc33978_is_sp(pin)) {
+ ret = mc33978_read(mpc, MC33978_REG_CONFIG, &data);
+ if (ret)
+ return ret;
+
+ if (data & MC33978_PINMASK(pin))
+ return -EINVAL;
+ }
+ arg = 1;
+ break;
+ case PIN_CONFIG_BIAS_DISABLE:
+ case PIN_CONFIG_BIAS_HIGH_IMPEDANCE:
+ ret = mc33978_get_pull(mpc, pin, &data);
+ if (ret)
+ return ret;
+ if (data != MC33978_TRISTATE)
+ return -EINVAL;
+ arg = 1;
+ break;
+ case PIN_CONFIG_DRIVE_STRENGTH:
+ ret = mc33978_get_ds(mpc, pin, &data);
+ if (ret)
+ return ret;
+ arg = data;
+ break;
+ default:
+ /*
+ * Ignore checkpatch warning: the pinctrl core specifically
+ * expects -ENOTSUPP to silently skip unsupported generic
+ * parameters. Using -EOPNOTSUPP causes debugfs read failures.
+ */
+ return -ENOTSUPP;
+ }
+
+ *config = pinconf_to_config_packed(param, arg);
+
+ return 0;
+}
+
+/*
+ * Hardware constraint regarding PIN_CONFIG_BIAS_PULL_UP/DOWN:
+ * The MC33978 utilizes active constant current sources (wetting currents)
+ * rather than passive pull-resistors. Since the equivalent ohmic resistance
+ * scales dynamically with the fluctuating board voltage (VBATP), computing
+ * a static ohm value is physically invalid.
+ * The driver intentionally ignores resistance arguments during configuration
+ * and continuously reports 0 ohms to the pinctrl framework.
+ */
+static int mc33978_pinconf_set(struct pinctrl_dev *pctldev, unsigned int pin,
+ unsigned long *configs, unsigned int num_configs)
+{
+ struct mc33978_pinctrl *mpc = pinctrl_dev_get_drvdata(pctldev);
+ enum pin_config_param param;
+ int ret = 0;
+ u32 arg;
+ int i;
+
+ guard(mutex)(&mpc->lock);
+
+ for (i = 0; i < num_configs; i++) {
+ param = pinconf_to_config_param(configs[i]);
+ arg = pinconf_to_config_argument(configs[i]);
+
+ /*
+ * The hardware physically lacks push-pull output drivers.
+ * By explicitly handling OPEN_DRAIN and OPEN_SOURCE here, we
+ * signal to gpiolib that we support these modes "natively".
+ * This crucially prevents gpiolib from falling back to its
+ * software emulation (which sets the pin to input mode to
+ * achieve High-Z). On the MC33978, input mode is NOT High-Z;
+ * it actively drives the line with a wetting current!
+ */
+ switch (param) {
+ case PIN_CONFIG_DRIVE_OPEN_SOURCE:
+ /* Setup topology only; do not turn on current yet */
+ if (mc33978_is_sp(pin))
+ ret = mc33978_update_bits(mpc, MC33978_REG_CONFIG,
+ MC33978_PINMASK(pin), 0);
+ break;
+ case PIN_CONFIG_BIAS_PULL_UP:
+ ret = mc33978_set_pull(mpc, pin, MC33978_PU);
+ break;
+ case PIN_CONFIG_DRIVE_OPEN_DRAIN:
+ if (!mc33978_is_sp(pin)) {
+ dev_err(mpc->dev, "Pin %u is SG and does not support open-drain\n",
+ pin);
+ return -EINVAL;
+ }
+ /* Setup topology only; do not turn on current yet */
+ ret = mc33978_update_bits(mpc, MC33978_REG_CONFIG,
+ MC33978_PINMASK(pin),
+ MC33978_PINMASK(pin));
+ break;
+ case PIN_CONFIG_BIAS_PULL_DOWN:
+ if (!mc33978_is_sp(pin)) {
+ dev_err(mpc->dev, "Pin %u is SG and does not support pull-down\n",
+ pin);
+ return -EINVAL;
+ }
+ ret = mc33978_set_pull(mpc, pin, MC33978_PD);
+ break;
+ /*
+ * The MC33978 uses active wetting currents rather than passive
+ * pull-resistors. Disabling the bias (pull-up/down) is
+ * physically equivalent to putting the pin into a
+ * high-impedance state. Both actions are achieved by isolating
+ * the pin via the hardware tri-state registers.
+ */
+ case PIN_CONFIG_BIAS_DISABLE:
+ case PIN_CONFIG_BIAS_HIGH_IMPEDANCE:
+ ret = mc33978_set_pull(mpc, pin, MC33978_TRISTATE);
+ break;
+ case PIN_CONFIG_DRIVE_STRENGTH_UA:
+ arg /= 1000;
+ fallthrough;
+ case PIN_CONFIG_DRIVE_STRENGTH:
+ ret = mc33978_set_ds(mpc, pin, arg);
+ break;
+ default:
+ /*
+ * Required by the pinctrl core to safely fall back or
+ * skip unsupported configs. Do not use -EOPNOTSUPP.
+ */
+ return -ENOTSUPP;
+ }
+
+ if (ret) {
+ dev_err(mpc->dev, "Failed to set config param %04x for pin %u: %d\n",
+ param, pin, ret);
+ return ret;
+ }
+ }
+
+ return 0;
+}
+
+static const struct pinconf_ops mc33978_pinconf_ops = {
+ .pin_config_get = mc33978_pinconf_get,
+ .pin_config_set = mc33978_pinconf_set,
+ .is_generic = true,
+};
+
+static int mc33978_direction_input(struct gpio_chip *chip, unsigned int offset)
+{
+ /* This chip is strictly an input device (comparators always active) */
+ return 0;
+}
+
+/*
+ * The hardware evaluates pin voltage against a threshold (default 4.0V)
+ * and reports an abstract contact status (1 = closed, 0 = open):
+ *
+ * SG (Switch-to-Ground) topology (pull-up current source):
+ * - Voltage > Threshold: Switch Open (HW reports 0) -> Physical High
+ * - Voltage < Threshold: Switch Closed (HW reports 1) -> Physical Low
+ *
+ * SB (Switch-to-Battery) topology (pull-down current source):
+ * - Voltage > Threshold: Switch Closed (HW reports 1) -> Physical High
+ * - Voltage < Threshold: Switch Open (HW reports 0) -> Physical Low
+ *
+ * We translate this contact status back into physical voltage levels by
+ * inverting the hardware status for all pins operating in SG topology.
+ */
+static int mc33978_read_in_state(struct mc33978_pinctrl *mpc,
+ unsigned long mask, unsigned long *state)
+{
+ u32 status, inv_mask;
+ u32 config_reg = 0;
+ int ret;
+
+ ret = mc33978_read(mpc, MC33978_REG_READ_IN, &status);
+ if (ret)
+ return ret;
+
+ /* Read CONFIG register only if the requested mask involves SP pins */
+ if (mask & MC33978_SP_MASK) {
+ ret = mc33978_read(mpc, MC33978_REG_CONFIG, &config_reg);
+ if (ret)
+ return ret;
+ }
+
+ /*
+ * Create an inversion mask for all pins currently operating in
+ * Switch-to-Ground (SG) topology. SG pins always have pull-ups.
+ * For SP pins, CONFIG bit 0 = Switch-to-Ground (PU),
+ * CONFIG bit 1 = Switch-to-Battery (PD).
+ */
+ inv_mask = MC33978_SG_MASK |
+ (~(config_reg << MC33978_NUM_SG) & MC33978_SP_MASK);
+
+ *state = (status ^ inv_mask) & mask;
+
+ return 0;
+}
+
+static int mc33978_get(struct gpio_chip *chip, unsigned int offset)
+{
+ struct mc33978_pinctrl *mpc = gpiochip_get_data(chip);
+ unsigned long state;
+ int ret;
+
+ guard(mutex)(&mpc->lock);
+
+ ret = mc33978_read_in_state(mpc, BIT(offset), &state);
+ if (ret)
+ return ret;
+
+ return !!(state & BIT(offset));
+}
+
+static int mc33978_get_multiple(struct gpio_chip *chip,
+ unsigned long *mask, unsigned long *bits)
+{
+ struct mc33978_pinctrl *mpc = gpiochip_get_data(chip);
+ unsigned long state;
+ int ret;
+
+ guard(mutex)(&mpc->lock);
+
+ ret = mc33978_read_in_state(mpc, *mask, &state);
+ if (ret)
+ return ret;
+
+ *bits = (*bits & ~*mask) | state;
+
+ return 0;
+}
+
+/*
+ * Emulate output states by routing or isolating active wetting currents.
+ * To turn the line ON, we disable the hardware tri-state (write 0).
+ * To turn the line OFF (High-Z), we enable tri-state (write 1).
+ *
+ * For Open-Source (Pull-Up): value=1 turns it ON, value=0 is High-Z.
+ * For Open-Drain (Pull-Down): value=0 turns it ON, value=1 is High-Z.
+ * We dynamically read the CONFIG register to determine the topology
+ * and invert the bits accordingly for Open-Drain pins.
+ *
+ * Note: The hardware physically lacks push-pull drivers. Toggling outputs
+ * via tri-state isolation may cause transient spikes.
+ */
+static int mc33978_update_tri_state(struct mc33978_pinctrl *mpc, u32 mask,
+ u32 bits)
+{
+ u32 sgmask = (mask & MC33978_SG_MASK) >> MC33978_SG_SHIFT;
+ u32 sgbits = (bits & MC33978_SG_MASK) >> MC33978_SG_SHIFT;
+ u32 spmask = (mask & MC33978_SP_MASK) >> MC33978_SP_SHIFT;
+ u32 spbits = (bits & MC33978_SP_MASK) >> MC33978_SP_SHIFT;
+ u32 config_reg = 0;
+ int ret = 0;
+
+ if (spmask) {
+ /* Read topology: 1 = PD (Open-Drain), 0 = PU (Open-Source) */
+ ret = mc33978_read(mpc, MC33978_REG_CONFIG, &config_reg);
+ if (ret)
+ return ret;
+
+ /*
+ * Invert bits for Open-Drain (PD) pins.
+ * The Open-Drain API contract expects value=1 to be High-Z.
+ */
+ spbits ^= (config_reg & spmask);
+
+ ret = mc33978_update_bits(mpc, MC33978_REG_TRI_SP, spmask,
+ ~spbits);
+ if (ret)
+ return ret;
+ }
+
+ /* SG pins are always Pull-Up (Open-Source), no inversion needed */
+ if (sgmask)
+ ret = mc33978_update_bits(mpc, MC33978_REG_TRI_SG, sgmask,
+ ~sgbits);
+
+ return ret;
+}
+
+static int mc33978_set(struct gpio_chip *chip, unsigned int offset, int value)
+{
+ struct mc33978_pinctrl *mpc = gpiochip_get_data(chip);
+ u32 mask = BIT(offset);
+ u32 bits = value ? mask : 0;
+
+ guard(mutex)(&mpc->lock);
+
+ return mc33978_update_tri_state(mpc, mask, bits);
+}
+
+static int mc33978_set_multiple(struct gpio_chip *chip,
+ unsigned long *mask, unsigned long *bits)
+{
+ struct mc33978_pinctrl *mpc = gpiochip_get_data(chip);
+
+ guard(mutex)(&mpc->lock);
+
+ return mc33978_update_tri_state(mpc, *mask, *bits);
+}
+
+static int mc33978_direction_output(struct gpio_chip *chip, unsigned int offset,
+ int value)
+{
+ return mc33978_set(chip, offset, value);
+}
+
+static int mc33978_gpio_child_to_parent_hwirq(struct gpio_chip *gc,
+ unsigned int child,
+ unsigned int child_type,
+ unsigned int *parent,
+ unsigned int *parent_type)
+{
+ *parent_type = child_type;
+ *parent = child;
+
+ return 0;
+}
+
+/*
+ * Defensive wrappers for hierarchical IRQ proxying.
+ *
+ * gpiolib's hierarchical allocation exposes a lifecycle gap: the child
+ * descriptor is registered before irq_domain_alloc_irqs_parent() fully
+ * instantiates the parent chip.
+ *
+ * During consumer probe (e.g., gpiod_to_irq()), irq_create_fwspec_mapping()
+ * allocates the hierarchy. As part of this, irq_domain_set_info() initializes
+ * the top-level irq_desc and calls __irq_set_handler(). If the irq_desc
+ * requires locking, __irq_get_desc_lock() will invoke the child's
+ * .irq_bus_lock before the parent allocation is complete.
+ *
+ * Upstream generic helpers (e.g., irq_chip_mask_parent) blindly dereference
+ * data->parent_data->chip, causing an immediate NULL pointer panic during
+ * this gap. These wrappers check for a valid parent chip to safely drop
+ * premature locking or masking events while the legacy subsystem hierarchy
+ * is still assembling itself.
+ */
+static void mc33978_gpio_irq_mask(struct irq_data *data)
+{
+ struct irq_data *parent = data->parent_data;
+
+ if (parent && parent->chip && parent->chip->irq_mask)
+ parent->chip->irq_mask(parent);
+}
+
+static void mc33978_gpio_irq_unmask(struct irq_data *data)
+{
+ struct irq_data *parent = data->parent_data;
+
+ if (parent && parent->chip && parent->chip->irq_unmask)
+ parent->chip->irq_unmask(parent);
+}
+
+static int mc33978_gpio_irq_set_type(struct irq_data *data, unsigned int type)
+{
+ struct irq_data *parent = data->parent_data;
+
+ if (parent && parent->chip && parent->chip->irq_set_type)
+ return parent->chip->irq_set_type(parent, type);
+
+ return -EINVAL;
+}
+
+static void mc33978_gpio_irq_bus_lock(struct irq_data *data)
+{
+ struct irq_data *parent = data->parent_data;
+
+ if (parent && parent->chip && parent->chip->irq_bus_lock)
+ parent->chip->irq_bus_lock(parent);
+}
+
+static void mc33978_gpio_irq_bus_sync_unlock(struct irq_data *data)
+{
+ struct irq_data *parent = data->parent_data;
+
+ if (parent && parent->chip && parent->chip->irq_bus_sync_unlock)
+ parent->chip->irq_bus_sync_unlock(parent);
+}
+
+static const struct irq_chip mc33978_gpio_irqchip = {
+ .name = "mc33978-gpio",
+ .irq_mask = mc33978_gpio_irq_mask,
+ .irq_unmask = mc33978_gpio_irq_unmask,
+ .irq_set_type = mc33978_gpio_irq_set_type,
+ .irq_bus_lock = mc33978_gpio_irq_bus_lock,
+ .irq_bus_sync_unlock = mc33978_gpio_irq_bus_sync_unlock,
+ .irq_set_wake = irq_chip_set_wake_parent,
+ .flags = IRQCHIP_IMMUTABLE,
+ GPIOCHIP_IRQ_RESOURCE_HELPERS,
+};
+
+static void mc33978_init_gpio_chip(struct mc33978_pinctrl *mpc,
+ struct device *dev)
+{
+ struct gpio_irq_chip *girq;
+
+ mpc->chip.label = dev_name(dev);
+ mpc->chip.direction_input = mc33978_direction_input;
+ mpc->chip.get = mc33978_get;
+ mpc->chip.get_multiple = mc33978_get_multiple;
+ mpc->chip.direction_output = mc33978_direction_output;
+ mpc->chip.set = mc33978_set;
+ mpc->chip.set_multiple = mc33978_set_multiple;
+ mpc->chip.set_config = gpiochip_generic_config;
+
+ mpc->chip.base = -1;
+ mpc->chip.ngpio = MC33978_NGPIO;
+ mpc->chip.can_sleep = true;
+ mpc->chip.parent = dev;
+ mpc->chip.owner = THIS_MODULE;
+
+ girq = &mpc->chip.irq;
+ gpio_irq_chip_set_chip(girq, &mc33978_gpio_irqchip);
+ girq->fwnode = dev_fwnode(dev);
+ girq->parent_domain = mpc->domain;
+ girq->child_to_parent_hwirq = mc33978_gpio_child_to_parent_hwirq;
+ girq->handler = handle_simple_irq;
+ girq->default_type = IRQ_TYPE_NONE;
+}
+
+static void mc33978_init_pinctrl_desc(struct mc33978_pinctrl *mpc,
+ struct device *dev)
+{
+ mpc->pinctrl_desc.name = dev_name(dev);
+
+ mpc->pinctrl_desc.pctlops = &mc33978_pinctrl_ops;
+ mpc->pinctrl_desc.confops = &mc33978_pinconf_ops;
+ mpc->pinctrl_desc.pins = mc33978_pins;
+ mpc->pinctrl_desc.npins = MC33978_NGPIO;
+ mpc->pinctrl_desc.owner = THIS_MODULE;
+}
+
+static int mc33978_pinctrl_probe(struct platform_device *pdev)
+{
+ struct device *dev = &pdev->dev;
+ struct mc33978_pinctrl *mpc;
+ int ret;
+
+ device_set_node(dev, dev_fwnode(dev->parent));
+
+ mpc = devm_kzalloc(dev, sizeof(*mpc), GFP_KERNEL);
+ if (!mpc)
+ return -ENOMEM;
+
+ mpc->dev = dev;
+
+ mpc->regmap = dev_get_regmap(dev->parent, NULL);
+ if (!mpc->regmap)
+ return dev_err_probe(dev, -ENODEV, "Failed to get parent regmap\n");
+
+ mpc->domain = irq_find_matching_fwnode(dev_fwnode(dev->parent), DOMAIN_BUS_ANY);
+ if (!mpc->domain)
+ return dev_err_probe(dev, -ENODEV, "Failed to find parent IRQ domain\n");
+
+ mutex_init(&mpc->lock);
+
+ mc33978_init_gpio_chip(mpc, dev);
+ mc33978_init_pinctrl_desc(mpc, dev);
+
+ mpc->pctldev = devm_pinctrl_register(dev, &mpc->pinctrl_desc, mpc);
+ if (IS_ERR(mpc->pctldev))
+ return dev_err_probe(dev, PTR_ERR(mpc->pctldev),
+ "can't register pinctrl\n");
+
+ ret = devm_gpiochip_add_data(dev, &mpc->chip, mpc);
+ if (ret)
+ return dev_err_probe(dev, ret, "can't add GPIO chip\n");
+
+ ret = gpiochip_add_pin_range(&mpc->chip, dev_name(dev), 0, 0,
+ MC33978_NGPIO);
+ if (ret)
+ return dev_err_probe(dev, ret, "failed to add pin range\n");
+
+ platform_set_drvdata(pdev, mpc);
+
+ return 0;
+}
+
+static const struct platform_device_id mc33978_pinctrl_id[] = {
+ { "mc33978-pinctrl", },
+ { "mc34978-pinctrl", },
+ { }
+};
+MODULE_DEVICE_TABLE(platform, mc33978_pinctrl_id);
+
+static struct platform_driver mc33978_pinctrl_driver = {
+ .driver = {
+ .name = "mc33978-pinctrl",
+ },
+ .probe = mc33978_pinctrl_probe,
+ .id_table = mc33978_pinctrl_id,
+};
+module_platform_driver(mc33978_pinctrl_driver);
+
+MODULE_AUTHOR("David Jander <david@protonic.nl>");
+MODULE_DESCRIPTION("NXP MC33978/MC34978 pinctrl driver");
+MODULE_LICENSE("GPL");
--
2.47.3
^ permalink raw reply related
* [PATCH v8 5/6] hwmon: add NXP MC33978/MC34978 driver
From: Oleksij Rempel @ 2026-03-29 9:06 UTC (permalink / raw)
To: Guenter Roeck, Rob Herring, Krzysztof Kozlowski, Conor Dooley,
Lee Jones, Peter Rosin, Linus Walleij
Cc: Oleksij Rempel, kernel, linux-kernel, devicetree, linux-hwmon,
linux-gpio, David Jander
In-Reply-To: <20260329090601.532477-1-o.rempel@pengutronix.de>
Add hardware monitoring support for the NXP MC33978/MC34978 Multiple
Switch Detection Interface (MSDI).
The hardware utilizes a clear-on-read FAULT register, but physical
faults remain asserted as long as the underlying condition exists. This
asserts a global FAULT_STAT bit on the SPI bus. To handle this without
trapping the CPU in an interrupt storm, this driver implements the
following architecture:
- Requests a rising-edge nested IRQ (IRQF_TRIGGER_RISING) from the MFD
core to catch the initial 0 -> 1 transition of the global fault state.
- Caches hwmon-specific alarm bits and calculates state edges (XOR) to
isolate alarm transitions from system integrity faults.
- Implements a 1Hz delayed workqueue that polls the hardware as long as
any alarm is active. This compensates for the edge-triggered IRQ by
discovering secondary faults that occur without a rising edge, and
detecting when the hardware clears.
Signed-off-by: Oleksij Rempel <o.rempel@pengutronix.de>
---
changes v8:
- no changes
changes v7:
- Fix fault monitoring stall by unconditionally rearming on SPI read
errors.
- Fix use-after-free race during unbind by correcting devm registration
order.
changes v6:
- Protect clear-on-read FAULT register and state updates with hwmon_lock().
- Isolate hwmon alarm bits from system integrity bits to fix edge detection.
- Log system faults (SPI/HASH) as level-triggered and add temperature warning
logs.
- Refactor sysfs read callback into smaller subsystem-specific helpers.
- Fix probe race condition by calling mc33978_hwmon_update_faults() at the end
of probe instead of reading raw faults early.
- Expose static datasheet temperature limits via temp1_rated_min and
temp1_rated_max
- Introduce variant-specific hw_info data to correctly report the max
temperature
- Add a 1Hz delayed workqueue that polls the SPI bus while any alarm is active.
changes v5:
- no changes
changes v4:
- no changes
changes v3:
- no changes
changes v2:
- Switch from OF match table to platform_device_id
---
drivers/hwmon/Kconfig | 10 +
drivers/hwmon/Makefile | 1 +
drivers/hwmon/mc33978-hwmon.c | 548 ++++++++++++++++++++++++++++++++++
3 files changed, 559 insertions(+)
create mode 100644 drivers/hwmon/mc33978-hwmon.c
diff --git a/drivers/hwmon/Kconfig b/drivers/hwmon/Kconfig
index 328867242cb3..0c52e8268a20 100644
--- a/drivers/hwmon/Kconfig
+++ b/drivers/hwmon/Kconfig
@@ -700,6 +700,16 @@ config SENSORS_MC13783_ADC
help
Support for the A/D converter on MC13783 and MC13892 PMIC.
+config SENSORS_MC33978
+ tristate "NXP MC33978/MC34978 fault monitoring"
+ depends on MFD_MC33978
+ help
+ If you say yes here you get fault monitoring support for the
+ NXP MC33978/MC34978 Multiple Switch Detection Interface (MSDI).
+
+ This driver can also be built as a module. If so, the module
+ will be called mc33978-hwmon.
+
config SENSORS_MC33XS2410
tristate "MC33XS2410 HWMON support"
depends on PWM_MC33XS2410
diff --git a/drivers/hwmon/Makefile b/drivers/hwmon/Makefile
index 5833c807c688..4c3db5433a10 100644
--- a/drivers/hwmon/Makefile
+++ b/drivers/hwmon/Makefile
@@ -167,6 +167,7 @@ obj-$(CONFIG_SENSORS_MAX31790) += max31790.o
obj-$(CONFIG_MAX31827) += max31827.o
obj-$(CONFIG_SENSORS_MAX77705) += max77705-hwmon.o
obj-$(CONFIG_SENSORS_MC13783_ADC)+= mc13783-adc.o
+obj-$(CONFIG_SENSORS_MC33978) += mc33978-hwmon.o
obj-$(CONFIG_SENSORS_MC33XS2410) += mc33xs2410_hwmon.o
obj-$(CONFIG_SENSORS_MC34VR500) += mc34vr500.o
obj-$(CONFIG_SENSORS_MCP3021) += mcp3021.o
diff --git a/drivers/hwmon/mc33978-hwmon.c b/drivers/hwmon/mc33978-hwmon.c
new file mode 100644
index 000000000000..0333c0315e06
--- /dev/null
+++ b/drivers/hwmon/mc33978-hwmon.c
@@ -0,0 +1,548 @@
+// SPDX-License-Identifier: GPL-2.0-only
+// Copyright (c) 2026 Pengutronix, Oleksij Rempel <kernel@pengutronix.de>
+/*
+ * MC33978/MC34978 Hardware Monitor Driver
+ *
+ * Fault handling model:
+ *
+ * The FAULT register is clear-on-read for most bits, but persistent fault
+ * conditions remain asserted. The MFD core only harvests the aggregate
+ * FAULT_STAT indication from SPI responses and dispatches the hwmon child
+ * IRQ on that basis. Because a persistent fault can keep FAULT_STAT asserted,
+ * secondary fault assertions and fault clear events may not generate a fresh
+ * interrupt edge visible to the hwmon child.
+ *
+ * To provide stable hwmon alarm state, this driver:
+ * - caches only hwmon-relevant alarm bits
+ * - serializes FAULT register reads with cache updates
+ * - polls while any alarm remains active to detect secondary alarms and
+ * clearing edges
+ *
+ * Raw integrity bits such as SPI_ERROR and HASH are logged, but are not
+ * exported through hwmon alarm attributes.
+ */
+
+#include <linux/device.h>
+#include <linux/err.h>
+#include <linux/hwmon.h>
+#include <linux/interrupt.h>
+#include <linux/mod_devicetable.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/regmap.h>
+
+#include <linux/mfd/mc33978.h>
+
+/* Operating Temperature Ranges (Datasheet Rated) */
+#define MC33978_TEMP_MIN_MC (-40000)
+#define MC33978_TEMP_MAX_MC 125000
+#define MC34978_TEMP_MAX_MC 105000
+
+/* Thermal Warning threshold (~120C) */
+#define MC33978_TEMP_WARN_MC 120000
+
+/* Thermal Limit / tLIM (>155C) - Hardware enters CWET throttling */
+#define MC33978_TEMP_CRIT_MC 155000
+
+/* Hysteresis for tLIM recovery (Silicon must cool to <140C) */
+#define MC33978_TEMP_HYST_MC 15000
+
+/* VBATP (in0) IC Level thresholds */
+#define MC33978_VBATP_OV_MV 36000 /* Overvoltage limit */
+#define MC33978_VBATP_FUNC_MV 28000 /* Functional/Normal boundary */
+#define MC33978_VBATP_DEGRADED_MV 6000 /* Degraded parametrics start */
+#define MC33978_VBATP_UVLO_MV 4500 /* UV Rising Threshold max */
+
+/* VDDQ (in1) Logic Supply thresholds */
+#define MC33978_VDDQ_MAX_MV 5250 /* Operating Condition max */
+#define MC33978_VDDQ_MIN_MV 3000 /* Operating Condition min */
+#define MC33978_VDDQ_UV_MV 2800 /* UV Falling Threshold max */
+
+#define MC33978_FAULT_POLL_INTERVAL_MS 1000
+
+enum mc33978_hwmon_in_channels {
+ MC33978_IN_VBATP,
+ MC33978_IN_VDDQ,
+};
+
+struct mc33978_hwmon_priv {
+ struct device *dev;
+ struct device *hwmon_dev;
+ struct regmap *map;
+
+ const struct mc33978_hwmon_hw_info *hw_info;
+
+ int fault_irq;
+
+ /* Cached hwmon alarm bits, serialized by hwmon_lock(). */
+ u32 last_faults;
+
+ /*
+ * Background polling worker. Active only when faults are present
+ * to compensate for the lack of clearing/secondary edge interrupts.
+ */
+ struct delayed_work poll_work;
+};
+
+struct mc33978_hwmon_hw_info {
+ long rated_max_temp;
+};
+
+static const struct mc33978_hwmon_hw_info hwmon_hwinfo_mc33978 = {
+ .rated_max_temp = MC33978_TEMP_MAX_MC,
+};
+
+static const struct mc33978_hwmon_hw_info hwmon_hwinfo_mc34978 = {
+ .rated_max_temp = MC34978_TEMP_MAX_MC,
+};
+
+static int mc33978_hwmon_read_fault(struct mc33978_hwmon_priv *priv,
+ u32 *faults)
+{
+ unsigned int val;
+ int ret;
+
+ ret = regmap_read(priv->map, MC33978_REG_FAULT, &val);
+ if (ret)
+ return ret;
+
+ *faults = val;
+
+ return 0;
+}
+
+static void mc33978_hwmon_report_faults(struct mc33978_hwmon_priv *priv,
+ u32 new_faults)
+{
+ if (!new_faults)
+ return;
+
+ if (new_faults & MC33978_FAULT_TEMP_WARN)
+ dev_warn_ratelimited(priv->dev, "Temperature warning threshold reached\n");
+
+ if (new_faults & MC33978_FAULT_OT)
+ dev_crit_ratelimited(priv->dev, "Over-temperature fault detected!\n");
+
+ if (new_faults & MC33978_FAULT_OV)
+ dev_crit_ratelimited(priv->dev, "Over-voltage fault detected!\n");
+
+ if (new_faults & MC33978_FAULT_UV)
+ dev_err_ratelimited(priv->dev, "Under-voltage fault detected!\n");
+}
+
+static int mc33978_hwmon_update_faults(struct mc33978_hwmon_priv *priv)
+{
+ u32 old_faults, new_faults, changed_faults;
+ u32 alarm_faults = 0;
+ u32 faults = 0;
+ bool rearm;
+ int ret;
+
+ /*
+ * Serialize clear-on-read FAULT register access with cached alarm state
+ * updates and hwmon sysfs readers.
+ */
+ hwmon_lock(priv->hwmon_dev);
+ old_faults = priv->last_faults;
+
+ ret = mc33978_hwmon_read_fault(priv, &faults);
+ if (ret) {
+ hwmon_unlock(priv->hwmon_dev);
+ dev_err_ratelimited(priv->dev,
+ "failed to read fault register: %pe\n",
+ ERR_PTR(ret));
+ /*
+ * Always retry on read failure. If we drop the heartbeat during
+ * the initial fault before caching it, the edge-triggered IRQ
+ * will never fire again and permanently stall fault monitoring.
+ */
+ rearm = true;
+ goto out_poll;
+ }
+
+ /* Isolate hwmon alarm bits from system integrity bits */
+ alarm_faults = faults & MC33978_FAULT_ALARM_MASK;
+ changed_faults = alarm_faults ^ old_faults;
+ new_faults = alarm_faults & ~old_faults;
+ priv->last_faults = alarm_faults;
+
+ hwmon_unlock(priv->hwmon_dev);
+
+ if (faults & MC33978_FAULT_SPI_ERROR)
+ dev_err_ratelimited(priv->dev, "SPI communication error detected\n");
+ if (faults & MC33978_FAULT_HASH)
+ dev_err_ratelimited(priv->dev, "SPI register hash mismatch detected\n");
+
+ if (new_faults)
+ mc33978_hwmon_report_faults(priv, new_faults);
+
+ if (changed_faults & MC33978_FAULT_UV)
+ hwmon_notify_event(priv->hwmon_dev, hwmon_in,
+ hwmon_in_lcrit_alarm, MC33978_IN_VBATP);
+
+ if (changed_faults & MC33978_FAULT_OV)
+ hwmon_notify_event(priv->hwmon_dev, hwmon_in,
+ hwmon_in_crit_alarm, MC33978_IN_VBATP);
+
+ if (changed_faults & MC33978_FAULT_TEMP_WARN)
+ hwmon_notify_event(priv->hwmon_dev, hwmon_temp,
+ hwmon_temp_max_alarm, 0);
+
+ if (changed_faults & MC33978_FAULT_OT)
+ hwmon_notify_event(priv->hwmon_dev, hwmon_temp,
+ hwmon_temp_crit_alarm, 0);
+
+ if (changed_faults)
+ hwmon_notify_event(priv->hwmon_dev, hwmon_chip,
+ hwmon_chip_alarms, 0);
+
+ rearm = !!alarm_faults;
+
+out_poll:
+ /*
+ * If any alarms are currently active, the global FAULT_STAT bit remains
+ * asserted. The hardware will not generate a new rising edge interrupt
+ * if a secondary fault occurs, nor will it interrupt when faults clear.
+ * Schedule a poll to detect both clearing edges and secondary alarms.
+ */
+ if (rearm)
+ mod_delayed_work(system_wq, &priv->poll_work,
+ msecs_to_jiffies(MC33978_FAULT_POLL_INTERVAL_MS));
+
+ return ret;
+}
+
+static irqreturn_t mc33978_hwmon_fault_irq(int irq, void *data)
+{
+ struct mc33978_hwmon_priv *priv = data;
+
+ mc33978_hwmon_update_faults(priv);
+
+ return IRQ_HANDLED;
+}
+
+static void mc33978_hwmon_poll_work(struct work_struct *work)
+{
+ struct mc33978_hwmon_priv *priv =
+ container_of(work, struct mc33978_hwmon_priv, poll_work.work);
+
+ mc33978_hwmon_update_faults(priv);
+}
+
+static umode_t mc33978_hwmon_is_visible(const void *data,
+ enum hwmon_sensor_types type,
+ u32 attr, int channel)
+{
+ switch (type) {
+ case hwmon_chip:
+ if (attr == hwmon_chip_alarms)
+ return 0444;
+ break;
+
+ case hwmon_temp:
+ switch (attr) {
+ case hwmon_temp_max:
+ case hwmon_temp_crit:
+ case hwmon_temp_crit_hyst:
+ case hwmon_temp_max_alarm:
+ case hwmon_temp_crit_alarm:
+ case hwmon_temp_rated_min:
+ case hwmon_temp_rated_max:
+ return 0444;
+ default:
+ break;
+ }
+ break;
+
+ case hwmon_in:
+ switch (attr) {
+ case hwmon_in_label:
+ case hwmon_in_max:
+ case hwmon_in_min:
+ case hwmon_in_lcrit:
+ return 0444;
+ case hwmon_in_crit:
+ if (channel == MC33978_IN_VBATP)
+ return 0444;
+ break;
+ case hwmon_in_crit_alarm:
+ case hwmon_in_lcrit_alarm:
+ if (channel == MC33978_IN_VBATP)
+ return 0444;
+ break;
+ }
+ break;
+ default:
+ break;
+ }
+
+ return 0;
+}
+
+static int mc33978_hwmon_read_chip(struct mc33978_hwmon_priv *priv, u32 attr,
+ long *val)
+{
+ if (attr == hwmon_chip_alarms) {
+ *val = priv->last_faults;
+ return 0;
+ }
+
+ return -EOPNOTSUPP;
+}
+
+static int mc33978_hwmon_read_in_vbatp(struct mc33978_hwmon_priv *priv,
+ u32 attr, long *val)
+{
+ switch (attr) {
+ case hwmon_in_crit:
+ *val = MC33978_VBATP_OV_MV;
+ return 0;
+ case hwmon_in_max:
+ *val = MC33978_VBATP_FUNC_MV;
+ return 0;
+ case hwmon_in_min:
+ *val = MC33978_VBATP_DEGRADED_MV;
+ return 0;
+ case hwmon_in_lcrit:
+ *val = MC33978_VBATP_UVLO_MV;
+ return 0;
+ case hwmon_in_crit_alarm:
+ *val = !!(priv->last_faults & MC33978_FAULT_OV);
+ return 0;
+ case hwmon_in_lcrit_alarm:
+ *val = !!(priv->last_faults & MC33978_FAULT_UV);
+ return 0;
+ default:
+ break;
+ }
+
+ return -EOPNOTSUPP;
+}
+
+static int mc33978_hwmon_read_in_vddq(u32 attr, long *val)
+{
+ switch (attr) {
+ case hwmon_in_max:
+ *val = MC33978_VDDQ_MAX_MV;
+ return 0;
+ case hwmon_in_min:
+ *val = MC33978_VDDQ_MIN_MV;
+ return 0;
+ case hwmon_in_lcrit:
+ *val = MC33978_VDDQ_UV_MV;
+ return 0;
+ default:
+ break;
+ }
+
+ return -EOPNOTSUPP;
+}
+
+static int mc33978_hwmon_read_in(struct mc33978_hwmon_priv *priv, u32 attr,
+ int channel, long *val)
+{
+ switch (channel) {
+ case MC33978_IN_VBATP:
+ return mc33978_hwmon_read_in_vbatp(priv, attr, val);
+ case MC33978_IN_VDDQ:
+ return mc33978_hwmon_read_in_vddq(attr, val);
+ default:
+ break;
+ }
+
+ return -EOPNOTSUPP;
+}
+
+static int mc33978_hwmon_read_temp(struct mc33978_hwmon_priv *priv, u32 attr,
+ long *val)
+{
+ switch (attr) {
+ case hwmon_temp_max:
+ *val = MC33978_TEMP_WARN_MC;
+ return 0;
+ case hwmon_temp_crit:
+ *val = MC33978_TEMP_CRIT_MC;
+ return 0;
+ case hwmon_temp_crit_hyst:
+ *val = MC33978_TEMP_CRIT_MC - MC33978_TEMP_HYST_MC;
+ return 0;
+ case hwmon_temp_max_alarm:
+ *val = !!(priv->last_faults & MC33978_FAULT_TEMP_WARN);
+ return 0;
+ case hwmon_temp_crit_alarm:
+ *val = !!(priv->last_faults & MC33978_FAULT_OT);
+ return 0;
+ case hwmon_temp_rated_min:
+ *val = MC33978_TEMP_MIN_MC;
+ return 0;
+ case hwmon_temp_rated_max:
+ *val = priv->hw_info->rated_max_temp;
+ return 0;
+ default:
+ break;
+ }
+
+ return -EOPNOTSUPP;
+}
+
+static int mc33978_hwmon_read(struct device *dev,
+ enum hwmon_sensor_types type,
+ u32 attr, int channel, long *val)
+{
+ struct mc33978_hwmon_priv *priv = dev_get_drvdata(dev);
+
+ switch (type) {
+ case hwmon_chip:
+ return mc33978_hwmon_read_chip(priv, attr, val);
+ case hwmon_in:
+ return mc33978_hwmon_read_in(priv, attr, channel, val);
+ case hwmon_temp:
+ return mc33978_hwmon_read_temp(priv, attr, val);
+ default:
+ break;
+ }
+
+ return -EOPNOTSUPP;
+}
+
+static int mc33978_hwmon_read_string(struct device *dev,
+ enum hwmon_sensor_types type,
+ u32 attr, int channel, const char **str)
+{
+ /* Only in_label is supported for string reads */
+ if (type != hwmon_in || attr != hwmon_in_label)
+ return -EOPNOTSUPP;
+
+ switch (channel) {
+ case MC33978_IN_VBATP:
+ *str = "VBATP";
+ return 0;
+ case MC33978_IN_VDDQ:
+ *str = "VDDQ";
+ return 0;
+ default:
+ return -EINVAL;
+ }
+}
+
+static const struct hwmon_channel_info * const mc33978_hwmon_info[] = {
+ HWMON_CHANNEL_INFO(chip,
+ HWMON_C_ALARMS),
+ HWMON_CHANNEL_INFO(temp,
+ HWMON_T_MAX | HWMON_T_CRIT | HWMON_T_CRIT_HYST |
+ HWMON_T_MAX_ALARM | HWMON_T_CRIT_ALARM |
+ HWMON_T_RATED_MIN | HWMON_T_RATED_MAX),
+ HWMON_CHANNEL_INFO(in,
+ /* Index 0: MC33978_IN_VBATP */
+ HWMON_I_LABEL | HWMON_I_CRIT | HWMON_I_MAX |
+ HWMON_I_MIN | HWMON_I_LCRIT |
+ HWMON_I_CRIT_ALARM | HWMON_I_LCRIT_ALARM,
+
+ /* Index 1: MC33978_IN_VDDQ */
+ HWMON_I_LABEL | HWMON_I_MAX | HWMON_I_MIN |
+ HWMON_I_LCRIT),
+ NULL
+};
+
+static const struct hwmon_ops mc33978_hwmon_ops = {
+ .is_visible = mc33978_hwmon_is_visible,
+ .read_string = mc33978_hwmon_read_string,
+ .read = mc33978_hwmon_read,
+};
+
+static const struct hwmon_chip_info mc33978_hwmon_chip_info = {
+ .ops = &mc33978_hwmon_ops,
+ .info = mc33978_hwmon_info,
+};
+
+static void mc33978_hwmon_action_cancel_work(void *data)
+{
+ struct mc33978_hwmon_priv *priv = data;
+
+ cancel_delayed_work_sync(&priv->poll_work);
+}
+
+static int mc33978_hwmon_probe(struct platform_device *pdev)
+{
+ const struct platform_device_id *id;
+ struct device *dev = &pdev->dev;
+ struct mc33978_hwmon_priv *priv;
+ struct device *hwmon_dev;
+ int ret;
+
+ priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
+ if (!priv)
+ return -ENOMEM;
+
+ priv->dev = dev;
+
+ id = platform_get_device_id(pdev);
+ if (!id || !id->driver_data)
+ return dev_err_probe(dev, -EINVAL, "missing device match data\n");
+
+ priv->hw_info = (const struct mc33978_hwmon_hw_info *)id->driver_data;
+
+ priv->map = dev_get_regmap(dev->parent, NULL);
+ if (!priv->map)
+ return dev_err_probe(dev, -ENODEV, "failed to get regmap\n");
+
+ platform_set_drvdata(pdev, priv);
+
+ INIT_DELAYED_WORK(&priv->poll_work, mc33978_hwmon_poll_work);
+
+ priv->fault_irq = platform_get_irq(pdev, 0);
+ if (priv->fault_irq < 0)
+ return priv->fault_irq;
+
+ hwmon_dev = devm_hwmon_device_register_with_info(dev, "mc33978", priv,
+ &mc33978_hwmon_chip_info,
+ NULL);
+ if (IS_ERR(hwmon_dev))
+ return dev_err_probe(dev, PTR_ERR(hwmon_dev),
+ "failed to register hwmon device\n");
+
+ priv->hwmon_dev = hwmon_dev;
+
+ ret = devm_add_action_or_reset(dev, mc33978_hwmon_action_cancel_work,
+ priv);
+ if (ret)
+ return ret;
+
+ /*
+ * The FAULT child IRQ is generated by the MFD core from transitions of
+ * the aggregated FAULT_STAT bus state. Request a rising-edge nested
+ * IRQ so the core dispatches the hwmon fault handler when faults become
+ * active.
+ *
+ * Fault clearing and secondary faults while FAULT_STAT remains asserted
+ * are handled by the hwmon polling path.
+ */
+ ret = devm_request_threaded_irq(dev, priv->fault_irq, NULL,
+ mc33978_hwmon_fault_irq,
+ IRQF_ONESHOT | IRQF_TRIGGER_RISING,
+ dev_name(dev), priv);
+ if (ret)
+ return dev_err_probe(dev, ret, "failed to request fault IRQ\n");
+
+ return mc33978_hwmon_update_faults(priv);
+}
+
+static const struct platform_device_id mc33978_hwmon_id[] = {
+ { "mc33978-hwmon", (kernel_ulong_t)&hwmon_hwinfo_mc33978 },
+ { "mc34978-hwmon", (kernel_ulong_t)&hwmon_hwinfo_mc34978 },
+ { }
+};
+MODULE_DEVICE_TABLE(platform, mc33978_hwmon_id);
+
+static struct platform_driver mc33978_hwmon_driver = {
+ .driver = {
+ .name = "mc33978-hwmon",
+ },
+ .probe = mc33978_hwmon_probe,
+ .id_table = mc33978_hwmon_id,
+};
+module_platform_driver(mc33978_hwmon_driver);
+
+MODULE_AUTHOR("Oleksij Rempel <kernel@pengutronix.de>");
+MODULE_DESCRIPTION("NXP MC33978/MC34978 Hardware Monitor Driver");
+MODULE_LICENSE("GPL");
--
2.47.3
^ permalink raw reply related
* [PATCH v8 1/6] dt-bindings: pinctrl: add NXP MC33978/MC34978 MSDI
From: Oleksij Rempel @ 2026-03-29 9:05 UTC (permalink / raw)
To: Guenter Roeck, Rob Herring, Krzysztof Kozlowski, Conor Dooley,
Lee Jones, Peter Rosin, Linus Walleij
Cc: Oleksij Rempel, kernel, linux-kernel, devicetree, linux-hwmon,
linux-gpio, David Jander
In-Reply-To: <20260329090601.532477-1-o.rempel@pengutronix.de>
Add device tree binding documentation for the NXP MC33978 and MC34978
Multiple Switch Detection Interface (MSDI) devices.
The MC33978 and MC34978 differ primarily in their operating temperature
ranges. While not software-detectable, providing specific compatible
strings allows the hwmon subsystem to correctly interpret thermal
thresholds and hardware faults.
These ICs monitor up to 22 mechanical switch contacts in automotive and
industrial environments. They provide configurable wetting currents to
break through contact oxidation and feature extensive hardware
protection against thermal overload and voltage transients (load
dumps/brown-outs).
The device interfaces via SPI. While it provides multiple functions, its
primary hardware purpose is pin/switch control. To accurately represent
the hardware as a single physical integrated circuit without unnecessary
DT overhead, all functions are flattened into a single pinctrl node:
- pinctrl: Exposing the 22 switch inputs (SG/SP pins) as a GPIO controller
and managing their pin configurations.
- hwmon: Exposing critical hardware faults (OT, OV, UV) and static
voltage/temperature thresholds.
- mux: Controlling the 24-to-1 analog multiplexer to route pin voltages,
internal temperature, or battery voltage to an external SoC ADC.
Signed-off-by: Oleksij Rempel <o.rempel@pengutronix.de>
Reviewed-by: Rob Herring (Arm) <robh@kernel.org>
Reviewed-by: Linus Walleij <linusw@kernel.org>
---
changes v8:
- Update IRQ_TYPE_* macros include path reference in documentation from
interrupt-controller.h to dt-bindings/interrupt-controller/irq.h.
- Add bias-disable, drive-open-drain, drive-open-source, and drive-strength
to the list of supported pin configuration properties.
changes v7:
- no changes
changes v6:
- add Reviewed-by: Rob Herring (Arm) <robh@kernel.org>
- add Reviewed-by: Linus Walleij <linusw@kernel.org>
changes v5:
- Commit Message: Added justification for distinct compatible strings
based on temperature ranges.
- Restricted pins property to an explicit enum of valid hardware pins
changes v4:
- Drop the standalone mfd/nxp,mc33978.yaml schema entirely.
- Move the unified device binding to bindings/pinctrl/nxp,mc33978.yaml,
- Remove the dedicated child node compatible strings (nxp,mc33978-pinctrl).
- Flatten the pinctrl/gpio properties directly into the main SPI device
node.
changes v3:
- Drop regular expression pattern from pinctrl child node and define
it as a standard property
- Reorder required properties list in MFD binding
- Remove stray blank line from the MFD binding devicetree example
- Replace unevaluatedProperties with additionalProperties in the pinctrl
binding
changes v2:
- Squashed MFD, pinctrl, hwmon, and mux bindings into a single patch
- Removed the empty hwmon child node
- Folded the mux-controller node into the parent MFD node
- Added vbatp-supply and vddq-supply to the required properties block
- Changed the example node name from mc33978@0 to gpio@0
- Removed unnecessary literal block scalars (|) from descriptions
- Documented SG, SP, and SB pin acronyms in the pinctrl description
- Added consumer polarity guidance (GPIO_ACTIVE_LOW/HIGH) for SG/SB
inputs, with a note on output circuit dependency
- Updated commit message
---
.../bindings/pinctrl/nxp,mc33978.yaml | 158 ++++++++++++++++++
1 file changed, 158 insertions(+)
create mode 100644 Documentation/devicetree/bindings/pinctrl/nxp,mc33978.yaml
diff --git a/Documentation/devicetree/bindings/pinctrl/nxp,mc33978.yaml b/Documentation/devicetree/bindings/pinctrl/nxp,mc33978.yaml
new file mode 100644
index 000000000000..2a3c565c3c03
--- /dev/null
+++ b/Documentation/devicetree/bindings/pinctrl/nxp,mc33978.yaml
@@ -0,0 +1,158 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/pinctrl/nxp,mc33978.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: NXP MC33978/MC34978 Multiple Switch Detection Interface
+
+maintainers:
+ - David Jander <david@protonic.nl>
+ - Oleksij Rempel <o.rempel@pengutronix.de>
+
+description: |
+ The MC33978 and MC34978 are Multiple Switch Detection Interface (MSDI)
+ devices with 22 switch inputs, integrated fault detection, and analog
+ multiplexer (AMUX) for voltage/temperature monitoring.
+
+ Pin numbering:
+ - Pins 0-13: SG0-SG13 (Switch-to-Ground inputs). These pins monitor
+ contacts closed to ground and typically require GPIO_ACTIVE_LOW
+ flags when used as digital inputs.
+ - Pins 14-21: SP0-SP7 (Programmable inputs). These can be configured
+ as SG (Switch-to-Ground) or SB (Switch-to-Battery) inputs. SB
+ inputs monitor contacts closed to the battery voltage and typically
+ require GPIO_ACTIVE_HIGH flags when used as digital inputs.
+
+ Output Emulation:
+ The hardware lacks standard push-pull output drivers. Outputs are emulated
+ by toggling the programmable wetting current sources (acting as pull-ups
+ or pull-downs) and the hardware tri-state registers. Because of this
+ physical constraint:
+ - Consumers using pins as outputs MUST flag them with GPIO_OPEN_DRAIN or
+ GPIO_OPEN_SOURCE in the device tree.
+ - Push-pull configurations are physically unsupported.
+ - The active polarity depends entirely on the external circuit (e.g., how
+ an LED is wired) and must be flagged accordingly by the consumer.
+
+allOf:
+ - $ref: /schemas/spi/spi-peripheral-props.yaml#
+
+properties:
+ compatible:
+ enum:
+ - nxp,mc33978
+ - nxp,mc34978
+
+ reg:
+ maxItems: 1
+ description: SPI chip select number
+
+ spi-max-frequency:
+ maximum: 8000000
+ description: Maximum SPI clock frequency (up to 8 MHz)
+
+ interrupts:
+ maxItems: 1
+ description:
+ INT_B pin interrupt. Active-low, indicates pin state changes or
+ fault conditions.
+
+ interrupt-controller: true
+
+ '#interrupt-cells':
+ const: 2
+ description:
+ First cell is the IRQ number (0-21 for pins, 22 for faults).
+ Second cell is the trigger type (IRQ_TYPE_* from dt-bindings/interrupt-controller/irq.h).
+
+ '#mux-control-cells':
+ const: 0
+ description:
+ Present if the device AMUX selector is used as a mux provider.
+ Consumers (e.g. io-channel-mux) must provide settle-time-us for the
+ external ADC sampling path.
+
+ vddq-supply:
+ description: Digital supply voltage
+
+ vbatp-supply:
+ description: Battery/power supply
+
+ gpio-controller: true
+
+ '#gpio-cells':
+ const: 2
+
+ ngpios:
+ const: 22
+
+patternProperties:
+ '^.*-grp$':
+ type: object
+ $ref: /schemas/pinctrl/pincfg-node.yaml#
+ additionalProperties: false
+ description: Pin configuration subnodes.
+ properties:
+ pins:
+ items:
+ enum: [sg0, sg1, sg2, sg3, sg4, sg5, sg6, sg7, sg8, sg9,
+ sg10, sg11, sg12, sg13, sp0, sp1, sp2, sp3,
+ sp4, sp5, sp6, sp7]
+
+ bias-pull-up: true
+ bias-pull-down: true
+ bias-high-impedance: true
+ bias-disable: true
+ drive-open-drain: true
+ drive-open-source: true
+ drive-strength:
+ enum: [2, 6, 8, 10, 12, 14, 16, 20]
+
+required:
+ - compatible
+ - reg
+ - interrupts
+ - interrupt-controller
+ - '#interrupt-cells'
+ - vddq-supply
+ - vbatp-supply
+ - gpio-controller
+ - '#gpio-cells'
+
+unevaluatedProperties: false
+
+examples:
+ - |
+ #include <dt-bindings/interrupt-controller/irq.h>
+ #include <dt-bindings/gpio/gpio.h>
+
+ spi {
+ #address-cells = <1>;
+ #size-cells = <0>;
+
+ msdi: gpio@0 {
+ compatible = "nxp,mc33978";
+ reg = <0>;
+ spi-max-frequency = <4000000>;
+
+ interrupt-parent = <&gpiog>;
+ interrupts = <9 IRQ_TYPE_LEVEL_LOW>;
+ interrupt-controller;
+ #interrupt-cells = <2>;
+
+ vddq-supply = <®_3v3>;
+ vbatp-supply = <®_12v>;
+
+ #mux-control-cells = <0>;
+
+ gpio-controller;
+ #gpio-cells = <2>;
+ ngpios = <22>;
+
+ door-grp {
+ pins = "sg0";
+ bias-high-impedance;
+ };
+ };
+ };
--
2.47.3
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