Merge tag 'm1-soc-bringup-v5' of https://github.com/AsahiLinux/linux into arm/apple-m1

Apple M1 SoC platform bring-up

This series brings up initial support for the Apple M1 SoC, used in the
2020 Mac Mini, MacBook Pro, and MacBook Air models.

The following features are supported in this initial port:

- UART (samsung-style) with earlycon support
- Interrupts, including affinity and IPIs (Apple Interrupt Controller)
- SMP (through standard spin-table support)
- simplefb-based framebuffer
- Devicetree for the Mac Mini (should work for the others too at this
  stage)

== Merge notes ==

This tag is based on v5.12-rc3 and includes the following two
dependencies merged in:

* Tip of arm64/for-next/fiq: 3889ba70102e
  This is a hard (build) dependency that adds support for FIQ
  interrupts, which is required for this SoC and the included AIC
  irqchip driver. It is already merged in the arm64 tree.

* From tty/tty-next: 71b25f4df984
  This commit includes the Samsung UART changes that have already
  been merged into the tty tree. It is nominally a soft dependency,
  but if this series is merged first it would trigger devicetree
  validation failures as the DT included in it depends on bindings
  introduced in the tty tree.

  There was a merge conflict here. It has been resolved the same
  way gregkh resolved it in a later tty merge, and both tty-next
  and torvalds/master merge cleanly with this series at this time.

This series additionally depends on the nVHE changes in [1] to boot,
but we are letting those get merged through arm64.

[1] https://lore.kernel.org/linux-arm-kernel/20210408131010.1109027-1-maz@kernel.org/T/#u

== Testing notes ==

This has been tested on an Apple M1 Mac Mini booting to a framebuffer
and serial console, with SMP and KASLR, with an arm64 defconfig
(+ CONFIG_FB_SIMPLE for the fb). In addition, the AIC driver now supports
running in EL1, tested in UP mode only.

== About the hardware ==

These machines officially support booting unsigned/user-provided
XNU-like kernels, with a very different boot protocol and devicetree
format. We are developing an initial bootloader, m1n1 [1], to take care
of as many hardware peculiarities as possible and present a standard
Linux arm64 boot protocol and device tree. In the future, I expect that
production setups will add U-Boot and perhaps GRUB into the boot chain,
to make the boot process similar to other ARM64 platforms.

The machines expose their debug UART over USB Type C, triggered with
vendor-specific USB-PD commands. Currently, the easiest way to get a
serial console on these machines is to use a second M1 box and a simple
USB C cable [2]. You can also build a DIY interface using an Arduino, a
FUSB302 chip or board, and a 1.2V UART-TTL adapter [3]. In the coming
weeks we will be designing an open hardware project to provide
serial/debug connectivity to these machines (and, hopefully, also
support other UART-over-Type C setups from other vendors). Please
contact me privately if you are interested in getting an early prototype
version of one of these devices.

We also have WIP/not merged yet support for loading kernels and
interacting via dwc3 usb-gadget, which works with a standard C-C or C-A
cable and any Linux host.

A quickstart guide to booting Linux kernels on these machines is
available at [4], and we are documenting the hardware at [5].

[1] https://github.com/AsahiLinux/m1n1/
[2] https://github.com/AsahiLinux/macvdmtool/
[3] https://github.com/AsahiLinux/vdmtool/
[4] https://github.com/AsahiLinux/docs/wiki/Developer-Quickstart
[5] https://github.com/AsahiLinux/docs/wiki

== Project Blurb ==

Asahi Linux is an open community project dedicated to developing and
maintaining mainline support for Apple Silicon on Linux. Feel free to
drop by #asahi and #asahi-dev on freenode to chat with us, or check
our website for more information on the project:

https://asahilinux.org/

Signed-off-by: Hector Martin <marcan@marcan.st>
* tag 'm1-soc-bringup-v5' of https://github.com/AsahiLinux/linux:
  arm64: apple: Add initial Apple Mac mini (M1, 2020) devicetree
  dt-bindings: display: Add apple,simple-framebuffer
  arm64: Kconfig: Introduce CONFIG_ARCH_APPLE
  irqchip/apple-aic: Add support for the Apple Interrupt Controller
  dt-bindings: interrupt-controller: Add DT bindings for apple-aic
  arm64: Move ICH_ sysreg bits from arm-gic-v3.h to sysreg.h
  of/address: Add infrastructure to declare MMIO as non-posted
  asm-generic/io.h: implement pci_remap_cfgspace using ioremap_np
  arm64: Implement ioremap_np() to map MMIO as nGnRnE
  docs: driver-api: device-io: Document ioremap() variants & access funcs
  docs: driver-api: device-io: Document I/O access functions
  asm-generic/io.h:  Add a non-posted variant of ioremap()
  arm64: arch_timer: Implement support for interrupt-names
  dt-bindings: timer: arm,arch_timer: Add interrupt-names support
  arm64: cputype: Add CPU implementor & types for the Apple M1 cores
  dt-bindings: arm: cpus: Add apple,firestorm & icestorm compatibles
  dt-bindings: arm: apple: Add bindings for Apple ARM platforms
  dt-bindings: vendor-prefixes: Add apple prefix

Link: https://lore.kernel.org/r/bdb18e9f-fcd7-1e31-2224-19c0e5090706@marcan.st
Signed-off-by: Arnd Bergmann <arnd@arndb.de>