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
