Messages in this thread | | | Subject | Re: Why do we need reset_control_get_optional() ? | From | Philipp Zabel <> | Date | Fri, 05 Aug 2016 10:55:58 +0200 |
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Am Samstag, den 30.07.2016, 22:13 +0200 schrieb Arnd Bergmann: > On Friday, July 29, 2016 3:08:15 PM CEST Philipp Zabel wrote: > > Hi Masahiro, > > > > Am Donnerstag, den 28.07.2016, 19:29 +0900 schrieb Masahiro Yamada: > > [...] > > > However, I think the following makes more sense: > > > > > > > > > menuconfig RESET_CONTROLLER > > > bool "Reset Controller Support" > > > depends on (ARCH_HAS_RESET_CONTROLLER || COMPILE_TEST) > > > default y > > > help > > > Generic Reset Controller support. > > > > That looks sensible to me. You'll only have to enable the reset > > controller framework if either some enabled architecture has a reset > > controller (in which case you want the driver for it to be activated by > > default), or if you want to compile test some of the reset drivers. > > This still doesn't let a platform 'select RESET_FOO', unless they > also select RESET_CONTROLLER and ARCH_HAS_RESET_CONTROLLER. > > Why do we need to guard all drivers inside of two symbols?
Does the platform have to select RESET_FOO at all? Wouldn't it be enough for RESET_FOO to have "default ARCH_FOO" ?
Currently ARCH_HAS_RESET_CONTROLLER is used to default y the RESET_CONTROLLER symbol. Maybe we should add another ARCH_REQUIRE_RESET_CONTROLLER and have that select RESET_CONTROLLER, similarly to how it is done for GPIOLIB?
config ARCH_HAS_RESET_CONTROLLER bool help Selecting this option from the architecture Kconfig enables the RESET_CONTROLLER framework by default but does not select it. Use it for architectures that still work without reset controller support and thus allow the user to disable it.
config ARCH_REQUIRE_RESET_CONTROLLER bool select RESET_CONTROLLER help Selecting this option from the architecture Kconfig selects the RESET_CONTROLLER framework. Use it for architectures that should not be built without the reset controller framework enabled.
menuconfig RESET_CONTROLLER bool "Reset Controller Support" default ARCH_HAS_RESET_CONTROLLER || COMPILE_TEST help Generic Reset Controller support.
This framework is designed to abstract reset handling of devices via GPIOs or SoC-internal reset controller modules.
If unsure, say no.
The platforms could then select one of the ARCH_*_RESET_CONTROLLER symbols and nobody would have to select RESET_CONTROLLER directly, for example:
menuconfig ARCH_TEGRA bool "NVIDIA Tegra" depends on ARCH_MULTI_V7 select ARCH_REQUIRE_GPIOLIB select ARCH_REQUIRE_RESET_CONTROLLER select ARCH_SUPPORTS_TRUSTED_FOUNDATIONS select ARM_AMBA select ARM_GIC select CLKSRC_MMIO select HAVE_ARM_SCU if SMP select HAVE_ARM_TWD if SMP select PINCTRL select PM_OPP select SOC_BUS help This enables support for NVIDIA Tegra based systems.
regards Philipp
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