Bus domains controllers allow to divided system on chip into multiple domains
that can be used to select by who hardware blocks could be accessed.
A domain could be a cluster of CPUs (or coprocessors), a range of addresses or
a group of hardware blocks.

Framework architecture is inspirated by pinctrl framework:
- a default configuration could be applied before bind the driver
- configurations could be apllied dynamically by drivers
- device node provides the bus domains configurations

An example of bus domains controller is STM32 ETZPC hardware block
which got 3 domains:
- secure: hardware blocks are only accessible by software running on trust
  zone.
- non-secure: hardware blocks are accessible by non-secure software (i.e.
  linux kernel).
- coprocessor: hardware blocks are only accessible by the corpocessor.
Up to 94 hardware blocks of the soc could be managed by ETZPC and 
assigned to one of the three domains.

At least two other hardware blocks can take benefits of this:
- ARM TZC-400: http://infocenter.arm.com/help/topic/com.arm.doc.100325_0001_02_en/arm_corelink_tzc400_trustzone_address_space_controller_trm_100325_0001_02_en.pdf
  which is able to manage up to 8 regions in address space.
- IMX Ressource Domain Controller (RDC): supports four domains and up to eight regions 

This version has been rebased on top of v5.1-rc1.

Benjamin

Benjamin Gaignard (7):
  devicetree: bindings: Document domains controller bindings
  domainsctrl: Introduce domains controller framework
  base: Add calls to domains controller
  devicetree: bindings: domainsctrl: Add STM32 ETZPC bindings
  bus: domainsctrl: Add driver for STM32 ETZPC controller
  ARM: dts: stm32: Add domainsctrl node for stm32mp157 SoC
  ARM: dts: stm32: enable domains controller node on stm32mp157c-ed1

 .../bindings/bus/domains/domainsctrl.txt           |  55 +++++
 .../bindings/bus/domains/st,stm32-etzpc.txt        |  14 ++
 arch/arm/boot/dts/stm32mp157c-ev1.dts              |   2 +
 arch/arm/boot/dts/stm32mp157c.dtsi                 |   7 +
 drivers/base/dd.c                                  |   9 +
 drivers/bus/Kconfig                                |   2 +
 drivers/bus/Makefile                               |   2 +
 drivers/bus/domains/Kconfig                        |  14 ++
 drivers/bus/domains/Makefile                       |   2 +
 drivers/bus/domains/domainsctrl.c                  | 234 +++++++++++++++++++++
 drivers/bus/domains/stm32-etzpc.c                  | 140 ++++++++++++
 include/dt-bindings/bus/domains/stm32-etzpc.h      |  25 +++
 include/linux/domainsctrl.h                        |  70 ++++++
 13 files changed, 576 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/bus/domains/domainsctrl.txt
 create mode 100644 Documentation/devicetree/bindings/bus/domains/st,stm32-etzpc.txt
 create mode 100644 drivers/bus/domains/Kconfig
 create mode 100644 drivers/bus/domains/Makefile
 create mode 100644 drivers/bus/domains/domainsctrl.c
 create mode 100644 drivers/bus/domains/stm32-etzpc.c
 create mode 100644 include/dt-bindings/bus/domains/stm32-etzpc.h
 create mode 100644 include/linux/domainsctrl.h

-- 
2.15.0


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