linux-toradex.git/arch/alpha/kernel/rtc.c, branch v3.15-rc8 Linux kernel for Apalis and Colibri modules alpha: Reorganize rtc handling 2013-11-17T00:33:16+00:00 Richard Henderson rth@twiddle.net 2013-07-13T22:49:45+00:00 85d0b3a573d8b711ee0c96199ac24a0f3283ed68 Discontinue use of GENERIC_CMOS_UPDATE; rely on the RTC subsystem. The marvel platform requires that the rtc only be touched from the boot cpu. This had been partially implemented with hooks for get/set_rtc_time, but read/update_persistent_clock were not handled. Move the hooks from the machine_vec to a special rtc_class_ops struct. We had read_persistent_clock managing the epoch against which the rtc hw is based, but this didn't apply to get_rtc_time or set_rtc_time. This resulted in incorrect values when hwclock(8) gets involved. Allow the epoch to be set from the kernel command-line, overriding the autodetection, which is doomed to fail in 2020. Further, by implementing the rtc ioctl function, we can expose this epoch to userland. Elide the alarm functions that RTC_DRV_CMOS implements. This was highly questionable on Alpha, since the interrupt is used by the system timer. Signed-off-by: Richard Henderson <rth@twiddle.net> 
Discontinue use of GENERIC_CMOS_UPDATE; rely on the RTC subsystem.

The marvel platform requires that the rtc only be touched from the
boot cpu.  This had been partially implemented with hooks for
get/set_rtc_time, but read/update_persistent_clock were not handled.
Move the hooks from the machine_vec to a special rtc_class_ops struct.

We had read_persistent_clock managing the epoch against which the
rtc hw is based, but this didn't apply to get_rtc_time or set_rtc_time.
This resulted in incorrect values when hwclock(8) gets involved.

Allow the epoch to be set from the kernel command-line, overriding
the autodetection, which is doomed to fail in 2020.  Further, by
implementing the rtc ioctl function, we can expose this epoch to
userland.

Elide the alarm functions that RTC_DRV_CMOS implements.  This was
highly questionable on Alpha, since the interrupt is used by the
system timer.

Signed-off-by: Richard Henderson <rth@twiddle.net>