Message-Id: <20250610-smc-6-15-v7-0-556cafd771d3@kernel.org>
Date: Tue, 10 Jun 2025 15:29:41 +0000
From: Sven Peter <sven@...nel.org>
To: Sven Peter <sven@...nel.org>, Janne Grunau <j@...nau.net>, 
 Alyssa Rosenzweig <alyssa@...enzweig.io>, Neal Gompa <neal@...pa.dev>, 
 Hector Martin <marcan@...can.st>, Linus Walleij <linus.walleij@...aro.org>, 
 Bartosz Golaszewski <brgl@...ev.pl>, Rob Herring <robh@...nel.org>, 
 Krzysztof Kozlowski <krzk+dt@...nel.org>, 
 Conor Dooley <conor+dt@...nel.org>, Sebastian Reichel <sre@...nel.org>, 
 Lee Jones <lee@...nel.org>, Marc Zyngier <maz@...nel.org>, 
 "Russell King (Oracle)" <rmk+kernel@...linux.org.uk>
Cc: asahi@...ts.linux.dev, linux-arm-kernel@...ts.infradead.org, 
 linux-gpio@...r.kernel.org, devicetree@...r.kernel.org, 
 linux-kernel@...r.kernel.org, linux-pm@...r.kernel.org, 
 Krzysztof Kozlowski <krzysztof.kozlowski@...aro.org>, 
 Sebastian Reichel <sebastian.reichel@...labora.com>
Subject: [PATCH v7 00/10] Apple Mac System Management Controller

Hi,

This series adds support for the System Management Controller found in
Apple Silicon devices which we model as a mfd. It also includes support
for the GPIO block and the power/reset block as sub-devices.

Changes between v6 and v7:
  - Rebased on 6.16-rc1
  - Dropped mfd- prefix from the macsmc driver name
  - Removed the check if the MBSE key exists in the reboot driver since
    we can rely on the device tree now
  - Changed my mail address to kernel.org

Changes between v5 and v6:
  - Actually reorder struct members this time, start comments with an
    uppercase letter, and use devm_ for mfd_register_devices instead of
    dropping those fixup commits by accident
  - Stefan's comment: Renamed ret to bfr in the reboot driver
  - Sebastian's comments on the reboot driver:
    - Moved Kconfig dependencies to MFD device and made reboot only
      depend on that one
    - Removed sysfs file to configure "reboot after power loss" for now
      since this probably belongs in a userspace tool that directly
      writes to nvmem instead
    - Dropped setting pdev->dev.of_node since that's already done
      automatically and adjusted #include to linux/mod_devicetable.h
    - Dropped MODULE_ALIAS which was probably a leftover from a previous
      version that did not use of_match_table
  - Rob's comments to the dt-bindings
    - Removed examples from sub-devices and added them to the main smc
      binding
    - Removed a spurious |

Changes between v4 and v5:
  - Alyssa's comments:
    - Made the WARN_ON in the reboot driver more obvious
    - Added missing brackets around a for loop in the reboot driver
    - Used min instead of open-coded variant inside the gpio driver
    - Reoder struct memebers to prevent padding inside the mfd driver
  - Lee's comments:
    - All comments now start with an uppercase letter
    - Removed apple_smc_read_ioft_scaled and apple_smc_read_f32_scaled
      since these are not yet used and likely don't belong into
      drivers/mfd
    - Relaced if (ret != 0) with if (ret) when possible
    - Used devm_platform_get_and_ioremap_resource to get and map the
      SRAM resource
    - Used reverse Christmas-tree formating when declaring variables
    - Dropped _platform left-overs from probe and remove functions
    - Removed dev_dbg prints which are no long required after
      development
    - Reworked is_alive/is_initialized so that it's obvious how errors
      during boot are propagated from the callback to the probe function
    - Used dev_warn instead of dev_err in a few places
    - Removed no-op apple_smc_rtkit_shmem_destroy; this required an
      additional change in rtkit.c because we had a check there that's a
      bit too strict
    - Removed struct resource in apple_smc_rtkit_shmem_setup and
      open-coded resource_contains instead
    - Unwrapped lines with less than 100 chars
    - Made sure to compile with W=1 and ran scripts/kernel-doc -v
      on macsmc.h once and fixed any fallout
  - Removed first_key/last_key from struct smc and moved
    apple_smc_find_first_key_index to the gpio driver since it's only
    used there anyway to find the index of the first GPIO key (gP00)
  - Return -EIO when a command fails instead of whatever SMC returns
    which does not map to Linux errnos on errors

Changes between v3 and v4:
  - Added documentation for all functions and structs
  - Fixed dt-bindings and re-ordered commits so that the mfd one comes
    last and can include the gpio subdevice
  - Added the reset driver and corresponding bindings
  - Reworked the atomic mode inside SMC since the previous implementation
    called mutex_lock from atomic context
  - Removed the backend split for now which lead to a quite intense discussion
    for the previous versions which hadn't been solved as far as I could tell
    from the old threads.
    It's also been 2+ years and I haven't heard of any backend implementation
    for T2 or even older macs. It's also unclear to me which sub-devices
    are actually useful there because at least GPIO and shutdown/reboot
    from this series will not work as-is there.
    I'd rather have this initial version which only supports M1+ macs upstream
    and then iterate there if any other backend is developed.
    I'll gladly help to re-introduce backend support if it's ever required.

v6: https://lore.kernel.org/asahi/20250515-smc-6-15-v6-0-c47b1ef4b0ae@svenpeter.dev/
v5: https://lore.kernel.org/asahi/20250511-smc-6-15-v5-0-f5980bdb18bd@svenpeter.dev/
v4: https://lore.kernel.org/asahi/20250503-smc-6-15-v4-0-500b9b6546fc@svenpeter.dev/
v3: https://lore.kernel.org/asahi/Y2qEpgIdpRTzTQbN@shell.armlinux.org.uk/
v2: https://lore.kernel.org/asahi/YxdInl2qzQWM+3bs@shell.armlinux.org.uk/
v1: https://lore.kernel.org/asahi/YxC5eZjGgd8xguDr@shell.armlinux.org.uk/

Best,

Sven

---
Hector Martin (5):
      gpio: Add new gpio-macsmc driver for Apple Macs
      power: reset: macsmc-reboot: Add driver for rebooting via Apple SMC
      arm64: dts: apple: t8103: Add SMC node
      arm64: dts: apple: t8112: Add SMC node
      arm64: dts: apple: t600x: Add SMC node

Russell King (Oracle) (2):
      dt-bindings: gpio: Add Apple Mac SMC GPIO block
      dt-bindings: mfd: Add Apple Mac System Management Controller

Sven Peter (3):
      dt-bindings: power: reboot: Add Apple Mac SMC Reboot Controller
      soc: apple: rtkit: Make shmem_destroy optional
      mfd: Add Apple Silicon System Management Controller

 .../devicetree/bindings/gpio/apple,smc-gpio.yaml   |  29 ++
 .../devicetree/bindings/mfd/apple,smc.yaml         |  79 ++++
 .../bindings/power/reset/apple,smc-reboot.yaml     |  40 ++
 MAINTAINERS                                        |   7 +
 arch/arm64/boot/dts/apple/t600x-die0.dtsi          |  35 ++
 arch/arm64/boot/dts/apple/t8103.dtsi               |  35 ++
 arch/arm64/boot/dts/apple/t8112.dtsi               |  35 ++
 drivers/gpio/Kconfig                               |  10 +
 drivers/gpio/Makefile                              |   1 +
 drivers/gpio/gpio-macsmc.c                         | 292 ++++++++++++
 drivers/mfd/Kconfig                                |  18 +
 drivers/mfd/Makefile                               |   1 +
 drivers/mfd/macsmc.c                               | 498 +++++++++++++++++++++
 drivers/power/reset/Kconfig                        |   9 +
 drivers/power/reset/Makefile                       |   1 +
 drivers/power/reset/macsmc-reboot.c                | 290 ++++++++++++
 drivers/soc/apple/rtkit.c                          |   3 +-
 include/linux/mfd/macsmc.h                         | 279 ++++++++++++
 18 files changed, 1660 insertions(+), 2 deletions(-)
---
base-commit: 19272b37aa4f83ca52bdf9c16d5d81bdd1354494
change-id: 20250304-smc-6-15-f0ed619e31d4

Best regards,
-- 
Sven Peter <sven@...nel.org>

Powered by blists - more mailing lists