[PATCH 00/19] Initial USB4/Thunderbolt support for Apple M1/M2/M3 SoCs
Joshua Peisach
jpeisach at ubuntu.com
Mon Aug 31 10:44:49 PDT 2026
On Sun Aug 30, 2026 at 4:19 PM EDT, Sven Peter wrote:
> Hi,
>
> This series adds initial USB4/Thunderbolt support for Apple Silicon
> M1, M2 and M3 SoCs. Each USB4 capable Type-C port comes with an ACIO
> ("Apple Converged I/O") block which contains a Cortex-M3 co-processor
> and the hardware implementing the USB4 router.
>
> The NHI and DART IOMMU are part of this ACIO block as well. Instead of
> being exposed as independent always-accessible devices the main SoC bus
> only gets a 16 MiB window into ACIO's MMIO space while its co-processor
> is running. It is not entirely clear whether this is ACIO's own address
> space or a window into the co-processor's address space.
>
> This is why the device tree represents the NHI and DART as children of
> ACIO with addresses relative to that window. The driver only populates
> these children after booting the co-processor and removes them again
> before powering ACIO down. This setup is slightly unusual but matches
> both the MMIO layout and the lifetime of the devices.
>
> ACIO also has rather strict ordering requirements: it can only be
> started after the Type-C PHY has been configured for USB4/Thunderbolt
> and has to be stopped again before the PHY is powered down. It also
> needs cable details which are only known to the Type-C port controller.
> The existing Type-C mode switch cannot express the required reverse
> teardown order, so the first three patches add a separate Thunderbolt
> switch and hook it up to the CD321x port controller.
>
> The next two patches add the bindings for the NHI and ACIO. The
> following patches then prepare the Thunderbolt core for the slightly
> different NHI register layout and interrupt handling, read the USB4
> router DROM from the device tree and add quirks for functionality not
> implemented by the Apple hardware.
>
> The main driver powers up ACIO, boots the co-processor, populates
> the DART and NHI children once their MMIO regions are accessible and
> registers the NHI with the software connection manager. The last three
> patches add the device tree nodes for the M1 and M2. M3 nodes will follow
> once the rest of the stack is upstream, but the current Thunderbolt/USB4
> code has already been successfully tested on those.
>
> Right now only XDomain connections and USB3-via-USB4 tunnels are
> supported. Both PCIe and DisplayPort tunnels will come later since those
> require additional work and reverse engineering that is not done yet.
> Suspend is also not supported yet and we actually have to prevent
> suspending whenever an active connection is present because we would
> otherwise resume into an SError.
>
> This series depends on the Apple CIO reset controller [1], the ATCPHY
> USB3-via-4 pipehandler support [2] and support for specifying the DART DMA
> aperture in the device tree [3], a fix for CD321x Thunderbolt
> altmode VDOs [4], and fixes for making the DPTX capabilities read fail
> gracefully [5]. I couldn't split it any further since the remaining
> patches now directly depend upon each other.
> Except for the dts changes the series applies cleanly without these
> dependencies though.
>
> For merging it probably makes most sense if all of this (except for the
> DTS changes) is taken through the thunderbolt tree once everything's been
> reviewed.
>
> Best,
>
> Sven
>
> [1] https://patch.msgid.link/20260821-b4-cio-reset-v2-0-2d045f80a424@kernel.org
> [2] https://patch.msgid.link/20260821-b4-atcphy-usb4-v1-0-45c0b741e0c0@kernel.org
> [3] https://patch.msgid.link/20260819-iommu-apple-dart-aperture-v1-0-252703f381aa@jannau.net
> [4] https://patch.msgid.link/20260813-b4-tipd-vdo-fix-v1-1-70317f2cd554@kernel.org
> [5] https://patch.msgid.link/20260829-b4-tbt-fixes-v3-0-e1fab6ac54fe@kernel.org
>
> Signed-off-by: Sven Peter <sven at kernel.org>
> ---
> Sven Peter (19):
> dt-bindings: usb: Add thunderbolt-switch property
> usb: typec: Add thunderbolt switch
> usb: typec: tipd: Hook up Thunderbolt switch for CD321x
> dt-bindings: thunderbolt: Add Apple USB4/Thunderbolt NHI
> dt-bindings: thunderbolt: Add Apple USB4/Thunderbolt ACIO block
> thunderbolt: Try reading host DROM from device tree first
> thunderbolt: Don't read the UID if we already know it
> thunderbolt: Allocate ring HopID before requesting the ring interrupt
> thunderbolt: Add ring_interrupt_active to tb_nhi_ops
> thunderbolt: Make the ring register layout configurable
> thunderbolt: Add ring_interrupt_mask to tb_nhi_ops
> thunderbolt: Add ring_configure to tb_nhi_ops
> thunderbolt: Add QUIRK_NO_DMA_PORT
> thunderbolt: Add QUIRK_NO_USB3_BW_ALLOC
> thunderbolt: Export symbols required by the Apple Silicon driver
> thunderbolt: Add Apple Silicon support
> arm64: dts: apple: t8103: Add USB4 ACIO and NHI
> arm64: dts: apple: t8112: Add USB4 ACIO and NHI
> arm64: dts: apple: t60xx: Add USB4 ACIO and NHI
>
> .../thunderbolt/apple,t8103-usb4-acio.yaml | 218 +++++
> .../bindings/thunderbolt/apple,t8103-usb4-nhi.yaml | 151 +++
> .../devicetree/bindings/usb/usb-switch.yaml | 6 +
> MAINTAINERS | 4 +
> arch/arm64/boot/dts/apple/t6002-j375d.dts | 67 ++
> arch/arm64/boot/dts/apple/t600x-dieX.dtsi | 384 ++++++++
> arch/arm64/boot/dts/apple/t600x-j314-j316.dtsi | 107 ++
> arch/arm64/boot/dts/apple/t600x-j375.dtsi | 137 +++
> arch/arm64/boot/dts/apple/t6022-j180d.dts | 202 ++++
> arch/arm64/boot/dts/apple/t6022-j475d.dts | 10 +
> arch/arm64/boot/dts/apple/t6022-jxxxd.dtsi | 57 ++
> arch/arm64/boot/dts/apple/t602x-dieX.dtsi | 384 ++++++++
> arch/arm64/boot/dts/apple/t8103-jxxx.dtsi | 61 ++
> arch/arm64/boot/dts/apple/t8103.dtsi | 188 ++++
> arch/arm64/boot/dts/apple/t8112-jxxx.dtsi | 61 ++
> arch/arm64/boot/dts/apple/t8112.dtsi | 190 ++++
> drivers/thunderbolt/Kconfig | 13 +
> drivers/thunderbolt/Makefile | 3 +
> drivers/thunderbolt/apple.c | 1028 ++++++++++++++++++++
> drivers/thunderbolt/cap.c | 2 +
> drivers/thunderbolt/ctl.c | 2 +
> drivers/thunderbolt/domain.c | 2 +
> drivers/thunderbolt/eeprom.c | 32 +-
> drivers/thunderbolt/nhi.c | 132 ++-
> drivers/thunderbolt/nhi.h | 32 +
> drivers/thunderbolt/switch.c | 19 +-
> drivers/thunderbolt/tb.c | 18 +
> drivers/thunderbolt/tb.h | 5 +
> drivers/thunderbolt/tunnel.c | 59 +-
> drivers/usb/typec/mux.c | 201 ++++
> drivers/usb/typec/mux.h | 12 +
> drivers/usb/typec/tipd/core.c | 37 +
> include/linux/thunderbolt.h | 3 +
> include/linux/usb/typec_mux.h | 114 +++
> 34 files changed, 3872 insertions(+), 69 deletions(-)
> ---
> base-commit: 78bb208b99e7d3314f670710fa9ee0a793682bca
> change-id: 20260829-b4-apple-soc-tbt-a00e873a52db
>
> Best regards,
> --
> Sven Peter <sven at kernel.org>
I unfortunately cannot test (afaik I do not have the devices) but a
glance over everything seems reasonable :)
Reviewed-by: Joshua Peisach <jpeisach at ubuntu.com>
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