linux-toradex.git/drivers/rtc/rtc-cmos.c, branch v4.4-rc6

rtc: cmos: clean up cmos_nvram_read()/cmos_nvram_write()

2015-09-05T11:19:09+00:00

The change removes redundant sysfs binary file boundary checks, since
this task is already done on caller side in fs/sysfs/file.c

Signed-off-by: Vladimir Zapolskiy 
Signed-off-by: Alexandre Belloni

rtc: cmos: Revert "rtc-cmos: Add an alarm disable quirk"

2015-09-05T11:19:08+00:00

Commit d5a1c7e3fc38 ("rtc-cmos: Add an alarm disable quirk") that
added a special quirk is not needed because [PATCH 1/2] of this
patchset makes the kernel more robust:
rtc-cmos: Cancel alarm timer if alarm time is equal to now+1 seconds

Signed-off-by: Adrian Huang 
Tested-by: Egbert Eich 
Tested-by: Diego Ercolani 
Cc: Borislav Petkov 
Signed-off-by: Alexandre Belloni

rtc: cmos: Cancel alarm timer if alarm time is equal to now+1 seconds

2015-09-05T11:19:08+00:00

Steps to reproduce the problem:
	1) Enable RTC wake-up option in BIOS Setup
	2) Issue one of these commands in the OS: "poweroff"
	   or "shutdown -h now"
	3) System will shut down and then reboot automatically

Root-cause of the issue:
	1) During the shutdown process, the hwclock utility is used
	   to save the system clock to hardware clock (RTC).
	2) The hwclock utility invokes ioctl() with RTC_UIE_ON. The
	   kernel configures the RTC alarm for the periodic interrupt
	   (every 1 second).
	3) The hwclock uitlity closes the /dev/rtc0 device, and the
	   kernel disables the RTC alarm irq (AIE bit of Register B)
	   via ioctl() with RTC_UIE_OFF. But, the configured alarm
	   time is the current_time + 1.
	4) After the next 1 second is elapsed, the AF (alarm
	   interrupt flag) of Register C is set.
	5) The S5 handler in BIOS is invoked to configure alarm
	   registers (enable AIE bit and configure alarm date/time).
	   But, BIOS does not clear the previous interrupt status
	   during alarm configuration. Therefore, "AF=AIE=1" causes
	   the rtc device to trigger an interrupt.
	6) So, the machine reboots automatically right after shutdown.

This patch cancels the alarm timer if the following condictions are
met (suggested by Alexandre):
	1) The configured alarm time is equal to current_time + 1
	   seconds.
	2) The AIE timer is not in use.

The member 'alarm_expires' is introduced in struct cmos_rtc because
of the following reasons:
	1) The configured alarm time can be retrieved from
	   cmos_read_alarm(), but we need to take the 'wrapped
	   timestamp' and 'time rollover' into consideration. The
	   function __rtc_read_alarm() eliminates the concerns. To
	   avoid the duplicated code in the lower level RTC driver,
	   invoking __rtc_read_alarm from the lower level RTC driver
	   is not encouraged. Moreover, the compilation error 'the
	   undefined __rtc_read_alarm" is observed if the lower level
	   RTC driver is compiled as a kernel module.
	2) The uie_rtctimer.node.expires and aie_timer.node.expires can
	   be retrieved for the configured alarm time. But, the problem
	   is that either of them might configure the CMOS alarm time.
	   We cannot make sure UIE timer or AIE tiemr configured the
	   CMOS alarm time before. (uie_rtctimer or aie_timer is enabled
	   and then is disabled).
	3) The patch introduces the member 'alarm_expires' to keep the
	   newly configured alarm time, so the above-mentioned concerns
	   can be eliminated.

The issue goes away after 20-time shutdown tests.

Signed-off-by: Adrian Huang 
Tested-by: Egbert Eich 
Tested-by: Diego Ercolani 
Cc: Borislav Petkov 
Signed-off-by: Alexandre Belloni

rtc: use more standard kernel logging styles

2015-04-17T13:04:02+00:00

Neaten the logging a bit by adding #define pr_fmt

Miscellanea:

o Remove __FILE__/__func__ uses
o Coalesce formats adding missing spaces
o Align arguments
o (rtc-cmos) Integrated 2 consecutive messages

Signed-off-by: Joe Perches 
Acked-by: Alexandre Belloni 
Cc: Alessandro Zummo 
Cc: Joshua Kinard 
Cc: Chanwoo Choi 
Reviewed-by: Krzysztof Kozlowski 
Tested-by: Krzysztof Kozlowski 
Cc: Aaro Koskinen 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

rtc: remove use of seq_printf return value

2015-04-15T23:35:24+00:00

The seq_printf return value, because it's frequently misused,
will eventually be converted to void.

See: commit 1f33c41c03da ("seq_file: Rename seq_overflow() to
     seq_has_overflowed() and make public")

Signed-off-by: Joe Perches 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

rtc-cmos: fix wakeup from S5 without CONFIG_PM_SLEEP

2014-10-14T00:18:19+00:00

Commit b5ada4600dfd ("drivers/rtc/rtc-cmos.c: fix compilation warning
when !CONFIG_PM_SLEEP") broke wakeup from S5 by making cmos_poweroff a
nop unless CONFIG_PM_SLEEP was defined.

Fix this by restricting the #ifdef to cmos_resume and restoring the old
dependency on CONFIG_PM for cmos_suspend and cmos_poweroff.

Signed-off-by: Daniel Glöckner 
Cc: Mika Westerberg 
Cc: Alessandro Zummo 
Cc: 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

drivers/rtc/rtc-cmos.c: drivers/char/rtc.c features for DECstation support

2014-06-06T23:08:07+00:00

This brings in drivers/char/rtc.c functionality required for DECstation
and, should the maintainers decide to switch, Alpha systems to use
rtc-cmos.

Specifically these features are made available:

* RTC iomem rather than x86/PCI port I/O mapping, controlled with the
  RTC_IOMAPPED macro as with the original driver.  The DS1287A chip in all
  DECstation systems is mapped in the host bus address space as a
  contiguous block of 64 32-bit words of which the least significant byte
  accesses the RTC chip for both reads and writes.  All the address and
  data window register accesses are made transparently by the chipset glue
  logic so that the device appears directly mapped on the host bus.

* A way to set the size of the address space explicitly with the
  newly-added `address_space' member of the platform part of the RTC
  device structure.  This avoids the unreliable heuristics that does not
  work in a setup where the RTC is not explicitly accessed with the usual
  address and data window register pair.

* The ability to use the RTC periodic interrupt as a system clock
  device, which is implemented by arch/mips/kernel/cevt-ds1287.c for
  DECstation systems and takes the RTC interrupt away from the RTC driver.
   Eventually hooking back to the clock device's interrupt handler should
  be possible for the purpose of the alarm clock and possibly also
  update-in-progress interrupt, but this is not done by this change.

  o To avoid interfering with the clock interrupt all the places where
    the RTC interrupt mask is fiddled with are only executed if and IRQ
    has been assigned to the RTC driver.

  o To avoid changing the clock setup Register A is not fiddled with
    if CMOS_RTC_FLAGS_NOFREQ is set in the newly-added `flags' member of
    the platform part of the RTC device structure.  Originally, in
    drivers/char/rtc.c, this was keyed with the absence of the RTC
    interrupt, just like the interrupt mask, but there only the periodic
    interrupt frequency is set, whereas rtc-cmos also sets the divider
    bits.  Therefore a new flag is introduced so that systems where the
    RTC interrupt is not usable rather than used as a system clock device
    can fully initialise the RTC.

* A small clean-up is made to the IRQ assignment code that makes the IRQ
  number hardcoded to -1 rather than arbitrary -ENXIO (or whatever error
  happens to be returned by platform_get_irq) where no IRQ has been
  assigned to the RTC driver (NO_IRQ might be another candidate, but it
  looks like this macro has inconsistent or missing definitions and
  limited use and might therefore be unsafe).

Verified to work correctly with a DECstation 5000/240 system.

[akpm@linux-foundation.org: fix weird code layout]
Signed-off-by: Maciej W. Rozycki 
Cc: Alessandro Zummo 
Cc: Ralf Baechle 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

drivers/rtc/rtc-cmos.c: fix compilation warning when !CONFIG_PM_SLEEP

2014-04-03T23:21:21+00:00

CONFIG_PM will be set also if only CONFIG_PM_RUNTIME is set which causes
the compiler to emit following warning:

  drivers/rtc/rtc-cmos.c:845:12: warning: =E2=80=98cmos_resume=E2=80=99 defined but not used [-Wunused-function]

Fix this by using CONFIG_PM_SLEEP instead of CONFIG_PM and removing it
from the driver pm ops as this has been taken care by
SIMPLE_DEV_PM_OPS() already.

Signed-off-by: Mika Westerberg 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

drivers/rtc/rtc-cmos.c: propagate hpet_register_irq_handler() failure

2014-01-24T00:37:00+00:00

If hpet_register_irq_handler() fails, cmos_do_probe() will incorrectly
return 0.

Reported-by: Julia Lawall 
Cc: John Stultz 
Cc: Grant Likely 
Cc: Rob Herring 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

drivers/rtc/rtc-cmos.c: remove superfluous name cast

2014-01-24T00:36:59+00:00

device_driver.name is "const char *"

Signed-off-by: Geert Uytterhoeven 
Cc: Alessandro Zummo 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds