lkml.org 
[lkml]   [2016]   [Aug]   [5]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
SubjectRe: Why do we need reset_control_get_optional() ?
From
Date
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

\
 
 \ /
  Last update: 2016-08-05 11:21    [W:0.429 / U:0.112 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site