[v2,0/8] Apple SoC PMGR device power states driver

Message

Hector Martin Oct. 25, 2021, 2:47 p.m. UTC

This series adds the driver for the Apple PMGR device power state
registers. These registers can clockgate and (in some cases) powergate
specific SoC blocks. They also control the reset line, and can have
additional features such as automatic power management.

The current driver supports only the lowest/highest power states,
provided via the genpd framework, plus reset support provided via
the reset subsystem.

Apple's PMGRs (there are two in the T8103) have a uniform register
bit layout (sometimes with varying features). To be able to support
multiple SoC generations as well as express pd relationships
dynamically, this binding describes each PMGR power state control
as a single devicetree node. Future SoC generations are expected to
retain backwards compatibility, allowing this driver to work on them
with only DT changes.

#1: MAINTAINERS updates, to go via the SoC tree to avert merge hell
#2-#3: Adds the required device tree bindings
#4: The driver itself.
#5: Somewhat unrelated DT change, but I wanted to get it out of the way
    for #7
#6: Instantiates the driver in t8103.dtsi.
#7: Adds runtime-pm support to the Samsung UART driver, as a first
    consumer.
#8: Instantiates a second UART, to more easily test this.

There are currently no consumers for the reset functionality, so
it is untested, but we will be testing it soon with the NVMe driver
(as it is required to allow driver re-binding to work properly).

== Changes since v1 ==

Mostly addressing review comments.

- DT schema fixes
- Reference one DT schema from the other
- Full example in MFD schema
- s/apple,domain-name/label/
- Split out MAINTAINERS patch
- Handle failed regmap reads more sanely
- Do not bind to apple,t8103-pmgr-pwrstate"

Hector Martin (8):
  MAINTAINERS: Add PMGR power state files to ARM/APPLE MACHINE
  dt-bindings: arm: apple: Add apple,pmgr binding
  dt-bindings: power: Add apple,pmgr-pwrstate binding
  soc: apple: Add driver for Apple PMGR power state controls
  arm64: dts: apple: t8103: Rename clk24 to clkref
  arm64: dts: apple: t8103: Add the UART PMGR tree
  tty: serial: samsung_tty: Support runtime PM
  arm64: dts: apple: t8103: Add UART2

 .../bindings/arm/apple/apple,pmgr.yaml        | 149 +++++++++
 .../bindings/power/apple,pmgr-pwrstate.yaml   |  69 +++++
 MAINTAINERS                                   |   3 +
 arch/arm64/boot/dts/apple/t8103-j274.dts      |   5 +
 arch/arm64/boot/dts/apple/t8103.dtsi          | 134 ++++++++-
 drivers/soc/Kconfig                           |   1 +
 drivers/soc/Makefile                          |   1 +
 drivers/soc/apple/Kconfig                     |  21 ++
 drivers/soc/apple/Makefile                    |   2 +
 drivers/soc/apple/apple-pmgr-pwrstate.c       | 282 ++++++++++++++++++
 drivers/tty/serial/samsung_tty.c              |  93 +++---
 11 files changed, 723 insertions(+), 37 deletions(-)
 create mode 100644 Documentation/devicetree/bindings/arm/apple/apple,pmgr.yaml
 create mode 100644 Documentation/devicetree/bindings/power/apple,pmgr-pwrstate.yaml
 create mode 100644 drivers/soc/apple/Kconfig
 create mode 100644 drivers/soc/apple/Makefile
 create mode 100644 drivers/soc/apple/apple-pmgr-pwrstate.c