rtc: avoid legacy drivers with generic framework

Kconfig tweaks to help reduce RTC configuration bugs, by avoiding
legacy RTC drivers when the generic RTC framework is enabled:

 - If rtc-cmos is selected, disable the legacy rtc driver;

 - When using generic RTC on x86, enable rtc-cmos by default;

 - In the old "chardev RTC" section of Kconfig, add a comment
   warning people off these (seven) legacy RTC drivers when
   the generic framework is in use.

People can still use the legacy drivers if they want (or need) to.

This doesn't fix the broken dependencies for the legacy "CMOS" RTC driver.
Ideally it would be a full list of platforms where it works, not a partial
list of ones where it won't.  Or better yet, it would depend on a
"HAVE_CMOS_RTC" flag defined by various platforms ...  surely there's a
Kconfig style guideline lurking there.

Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Acked-by: Alessandro Zummo <a.zummo@towertech.it>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
David Brownell 2008-04-28 02:11:52 -07:00 committed by Linus Torvalds
parent 77459b059b
commit c750090085
2 changed files with 11 additions and 5 deletions

View File

@ -732,9 +732,16 @@ config NVRAM
To compile this driver as a module, choose M here: the
module will be called nvram.
#
# These legacy RTC drivers just cause too many conflicts with the generic
# RTC framework ... let's not even try to coexist any more.
#
if RTC_LIB=n
config RTC
tristate "Enhanced Real Time Clock Support"
depends on !PPC && !PARISC && !IA64 && !M68K && !SPARC && !FRV && !ARM && !SUPERH && !S390 && !AVR32
depends on !PPC && !PARISC && !IA64 && !M68K && !SPARC && !FRV \
&& !ARM && !SUPERH && !S390 && !AVR32
---help---
If you say Y here and create a character special file /dev/rtc with
major number 10 and minor number 135 using mknod ("man mknod"), you
@ -840,6 +847,8 @@ config DS1302
will get access to the real time clock (or hardware clock) built
into your computer.
endif # RTC_LIB
config COBALT_LCD
bool "Support for Cobalt LCD"
depends on MIPS_COBALT

View File

@ -20,10 +20,6 @@ menuconfig RTC_CLASS
if RTC_CLASS
if GEN_RTC || RTC
comment "Conflicting RTC option has been selected, check GEN_RTC and RTC"
endif
config RTC_HCTOSYS
bool "Set system time from RTC on startup and resume"
depends on RTC_CLASS = y
@ -304,6 +300,7 @@ comment "Platform RTC drivers"
config RTC_DRV_CMOS
tristate "PC-style 'CMOS'"
depends on X86 || ALPHA || ARM || M32R || ATARI || PPC || MIPS
default y if X86
help
Say "yes" here to get direct support for the real time clock
found in every PC or ACPI-based system, and some other boards.