user/sven/linux.git/include/linux/rtc.h, branch v3.4.40

rtc: Provide flag for rtc devices that don't support UIE

2012-03-16T01:23:10Z

Richard Weinberger noticed that on some RTC hardware that doesn't support UIE mode, due to coarse granular alarms (like 1minute resolution), the current virtualized RTC support doesn't properly error out when UIE is enabled. Instead the current code queues an alarm for the next second, but it won't fire until up to a miniute later. This patch provides a generic way to flag this sort of hardware and fixes the issue on the mpc5121 where Richard noticed the problem. CC: stable@vger.kernel.org Reported-by: Richard Weinberger Tested-by: Richard Weinberger Signed-off-by: John Stultz

rtc: Limit RTC PIE frequency

2011-07-26T21:50:01Z

The RTC pie hrtimer is self rearming. We really need to limit the frequency to something sensible. Thus limit it to the 8192Hz max value from the rtc man documentation Cc: Willy Tarreau Cc: stable@kernel.org Signed-off-by: Thomas Gleixner [jstultz: slightly reworked to use RTC_MAX_FREQ value] Signed-off-by: John Stultz

drivers/rtc/rtc-mxc.c: remove defines already included in rtc.h

2011-05-27T00:12:33Z

[akpm@linux-foundation.org: retain the code comments] Signed-off-by: Wolfram Sang Cc: Vladimir Zapolskiy Cc: Alessandro Zummo Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

RTC: Fix early irqs caused by calling rtc_set_alarm too early

2011-03-30T01:44:05Z

When we register an rtc device at boot, we read the alarm value in hardware and set the rtc device's aie_timer to that value. The initial method to do this was to simply call rtc_set_alarm() with the value read from hardware. However, this may cause problems as rtc_set_alarm may enable interupts, and the RTC alarm might fire, which can cause invalid pointer dereferencing since the RTC registration is not complete. This patch solves the issue by initializing the rtc_device.aie_timer y hand via rtc_initialize_alarm(). This avoids any calls to the RTC hardware which might enable interrupts too early. CC: Thomas Gleixner CC: Alessandro Zummo Reported-by: Konrad Rzeszutek Wilk Tested-by: Konrad Rzeszutek Wilk Signed-off-by: John Stultz

RTC: Cleanup rtc_class_ops->update_irq_enable()

2011-03-09T19:23:37Z

Now that the generic code handles UIE mode irqs via periodic alarm interrupts, no one calls the rtc_class_ops->update_irq_enable() method anymore. This patch removes the driver hooks and implementations of update_irq_enable if no one else is calling it. CC: Thomas Gleixner CC: Alessandro Zummo CC: Marcelo Roberto Jimenez CC: rtc-linux@googlegroups.com Signed-off-by: John Stultz

RTC: Cleanup rtc_class_ops->irq_set_freq()

2011-03-09T19:23:35Z

With the generic rtc code now emulating PIE mode irqs via an hrtimer, no one calls the rtc_class_ops->irq_set_freq call. This patch removes the hook and deletes the driver functions if no one else calls them. CC: Thomas Gleixner CC: Alessandro Zummo CC: Marcelo Roberto Jimenez CC: rtc-linux@googlegroups.com Signed-off-by: John Stultz

RTC: Cleanup rtc_class_ops->irq_set_state

2011-03-09T19:23:34Z

With PIE mode interrupts now emulated in generic code via an hrtimer, no one calls rtc_class_ops->irq_set_state(), so this patch removes it along with driver implementations. CC: Thomas Gleixner CC: Alessandro Zummo CC: Marcelo Roberto Jimenez CC: rtc-linux@googlegroups.com Signed-off-by: John Stultz

RTC: Initialize kernel state from RTC

2011-03-09T19:22:50Z

Mark Brown pointed out a corner case: that RTC alarms should be allowed to be persistent across reboots if the hardware supported it. The rework of the generic layer to virtualize the RTC alarm virtualized much of the alarm handling, and removed the code used to read the alarm time from the hardware. Mark noted if we want the alarm to be persistent across reboots, we need to re-read the alarm value into the virtualized generic layer at boot up, so that the generic layer properly exposes that value. This patch restores much of the earlier removed rtc_read_alarm code and wires it in so that we set the kernel's alarm value to what we find in the hardware at boot time. NOTE: Not all hardware supports persistent RTC alarm state across system reset. rtc-cmos for example will keep the alarm time, but disables the AIE mode irq. Applications should not expect the RTC alarm to be valid after a system reset. We will preserve what we can, to represent the hardware state at boot, but its not guarenteed. Further, in the future, with multiplexed RTC alarms, the soonest alarm to fire may not be the one set via the /dev/rt ioctls. So an application may set the alarm with RTC_ALM_SET, but after a reset find that RTC_ALM_READ returns an earlier time. Again, we preserve what we can, but applications should not expect the RTC alarm state to persist across a system reset. Big thanks to Mark for pointing out the issue! Thanks also to Marcelo for helping think through the solution. CC: Mark Brown CC: Marcelo Roberto Jimenez CC: Thomas Gleixner CC: Alessandro Zummo CC: rtc-linux@googlegroups.com Reported-by: Mark Brown Signed-off-by: John Stultz

RTC: Re-enable UIE timer/polling emulation

2011-02-17T22:59:42Z

This patch re-enables UIE timer/polling emulation for rtc devices that do not support alarm irqs. CC: Uwe Kleine-König CC: Thomas Gleixner Reported-by: Uwe Kleine-König Tested-by: Uwe Kleine-König Signed-off-by: John Stultz

RTC: Revert UIE emulation removal

2011-02-17T22:59:41Z

Uwe pointed out that my alarm based UIE emulation is not sufficient to replace the older timer/polling based UIE emulation on devices where there is no alarm irq. This causes rtc devices without alarms to return -EINVAL to UIE ioctls. The fix is to re-instate the old timer/polling method for devices without alarm irqs. This patch reverts the following commits: 042620a018afcfba1d678062b62e46 - Remove UIE emulation 1daeddd5962acad1bea55e524fc0fa - Cleanup removed UIE emulation declaration b5cc8ca1c9c3a37eaddf709b2fd3e1 - Remove Kconfig symbol for UIE emulation The emulation mode will still need to be wired-in with a following patch before it will work. CC: Uwe Kleine-König CC: Thomas Gleixner Reported-by: Uwe Kleine-König Signed-off-by: John Stultz