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

rtc: switch to using is_visible() to control sysfs attributes

2015-09-05T11:19:07+00:00

Instead of creating wakealarm attribute manually, after the device has been
registered, let's rely on facilities provided by the attribute groups to
control which attributes are visible and which are not. This allows to
create all needed attributes at once, at the same time that we register RTC
class device.

Signed-off-by: Dmitry Torokhov 
Reviewed-by: Krzysztof Kozlowski 
Signed-off-by: Alexandre Belloni

rtc: switch wakealarm attribute to DEVICE_ATTR_RW

2015-09-05T11:19:07+00:00

Instead of using older style DEVICE_ATTR for wakealarm attribute let's
switch to using DEVICE_ATTR_RW that ensures consistent across the kernel
permissions on the attribute.

Signed-off-by: Dmitry Torokhov 
Reviewed-by: Krzysztof Kozlowski 
Signed-off-by: Alexandre Belloni

rtc: make rtc_does_wakealarm() return boolean

2015-09-05T11:19:07+00:00

Users of rtc_does_wakealarm() return value treat it as boolean so let's
change the signature accordingly.

Signed-off-by: Dmitry Torokhov 
Reviewed-by: Krzysztof Kozlowski 
Signed-off-by: Alexandre Belloni

rtc: convert class code to use dev_groups

2013-07-29T20:10:58+00:00

The dev_attrs field of struct class is going away soon, dev_groups
should be used instead.  This converts the rtc class code to use the
correct field.

Acked-by: Alessandro Zummo 
Signed-off-by: Greg Kroah-Hartman

rtc: add ability to push out an existing wakealarm using sysfs

2013-07-03T23:07:54+00:00

This adds the ability for the rtc sysfs code to handle += characters at
the beginning of a wakealarm setting string.  This will allow the user
to attempt to push out an existing wakealarm by a provided amount.

In the case that the += characters are provided but the alarm is not
active -EINVAL is returned.

his is useful, at least for my purposes in suspend/resume testing.  The
basic test goes something like:

1. Set a wake alarm from userspace 5 seconds in the future

2. Start the suspend process (echo mem > /sys/power/state)

3. After ~2.5 seconds if userspace is still running (using another
   thread to check this), move the wake alarm 5 more seconds

If the "move" involves an unset of the wakealarm then there's a period
   of time where the system is midway through suspending but has no wake
   alarm.  It will get stuck.

We'd rather not remove the "move" since the idea is to avoid a cancelled
suspend when the alarm fires _during_ suspend.  It is difficult for the
test to tell the difference between a suspend that was cancelled because
the alarm fired too early and a suspend that was

Signed-off-by: Bernie Thompson 
Cc: Alessandro Zummo 
Cc: Doug Anderson 
Cc: "Rafael J. Wysocki" 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

rtc_sysfs_show_hctosys(): display 0 if resume failed

2012-10-05T18:05:04+00:00

Without this patch /sys/class/rtc/$CONFIG_RTC_HCTOSYS_DEVICE/hctosys
contains a 1 (meaning "This rtc was used to initialize the system
clock") even if setting the time by do_settimeofday() at bootup failed.
The RTC can also be used to set the clock on resume, if it did 1,
otherwise 0.  Previously there was no indication if the RTC was used
to set the clock in resume.

This uses only CONFIG_RTC_HCTOSYS_DEVICE for conditional compilation
instead of it and CONFIG_RTC_HCTOSYS to be more consistent.
rtc_hctosys_ret was moved to class.c so class.c no longer depends on
hctosys.c.

[sfr@canb.auug.org.au: fix build]
Signed-off-by: David Fries 
Cc: Matthew Garrett 
Cc: Alessandro Zummo 
Cc: Uwe Kleine-König 
Signed-off-by: Stephen Rothwell 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

rtc/hctosys: only claim the RTC provided the system time if it did

2010-03-12T23:52:28+00:00

Without this patch /sys/class/rtc/$CONFIG_RTC_HCTOSYS_DEVICE/hctosys
contains a 1 (meaning "This rtc was used to initialize the system clock")
even if reading the time at bootup failed.

Moreover change error handling in rtc_hctosys() to use goto and so reduce
the indention level.

Signed-off-by: Uwe Kleine-König 
Cc: Paul Gortmaker 
Acked-by: Alessandro Zummo 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

rtc: add boot_timesource sysfs attribute

2009-09-23T14:39:46+00:00

CONFIG_RTC_HCTOSYS allows the kernel to read the system time from the RTC
at boot and resume, avoiding the need for userspace to do so.
Unfortunately userspace currently has no way to know whether this
configuration option is enabled and thus cannot sensibly choose whether to
run hwclock itself or not.  Add a hctosys sysfs attribute which indicates
whether a given RTC set the system clock.

Signed-off-by: Matthew Garrett 
Acked-by: Alessandro Zummo 
Cc: Mark Brown 
Cc: David Brownell 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

rtc: add the support for alarm time relative to current time in sysfs

2008-04-28T15:58:17+00:00

In current kernel if we want to set the alarm time, the absolute time the
seconds relative to 1970-01-01 00:00:00) should be written into
/sys/class/rtc/rtc0/wakealarm.  It is not convenient.

It is more reasonable to add the support for the alarm time relative to
current RTC time.(the unit is second)

For example:
If the RTC is required to generate alarm after 2 minutes, the following
will be OK.
	echo +120 > /sys/class/rtc/rtc0/wakealarm
or      echo +0x78 > /sys/class/rtc/rtc0/wakealarm

Signed-off-by: Zhao Yakui 
Signed-off-by: Zhang Rui 
Signed-off-by: David Brownell 
Cc: Alessandro Zummo 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

rtc-cmos alarm acts as oneshot

2008-02-06T18:41:13+00:00

Start making the rtc-cmos alarm act more like a oneshot alarm by disabling
that alarm after its IRQ fires.  (ACPI hooks are also needed.)

The Linux RTC framework has previously been a bit vague in this area, but
any other behavior is problematic and not very portable.  RTCs with full
YYYY-MM-DD HH:MM[:SS] alarms won't have a problem here.  Only ones with
partial match criteria, with the most visible example being the PC RTC, get
confused.  (Because the criteria will match repeatedly.)

Update comments relating to that oneshot behavior and timezone handling.
(Timezones are another issue that's mostly visible with rtc-cmos.  That's
because PCs often dual-boot MS-Windows, which likes its RTC to match local
wall-clock time instead of UTC.)

Signed-off-by: David Brownell 
Cc: Alessandro Zummo 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds