rtc: max77686: Allow the max77686 rtc to wakeup the system

This series add support for the Real Time clock present in the Maxim 77802
Power Managment IC.  The version number is quite high because it
previously was part of a bigger series [0] that aimed to add support for
all the devices in the max77802 PMIC.  But now that the max77802
dependencies were already merged for 3.17, the series were split but I
kept the version numbering.

While working on the max77802 rtc support a lot of feedback was given and
the issues pointed out also apply to a driver for a similar PMIC RTC
(max77686).  So patches 01/06 to 05/06 in the series are cleanups for the
max77686 driver and patch 06/06 adds the support for the max77802 RTC.

The series were tested on an Exynos5250 Snow (max77686) and
Exynos5420 Peach Pit (max77802) machines.

This patch (of 6):

The max77686 includes an RTC that keeps power during suspend.  It's
convenient to be able to use it as a wakeup source.

Signed-off-by: Doug Anderson <dianders@chromium.org>
Signed-off-by: Javier Martinez Canillas <javier.martinez@collabora.co.uk>
Reviewed-by: Krzysztof Kozlowski <k.kozlowski@samsung.com>
Cc: Alessandro Zummo <a.zummo@towertech.it>
Cc: Olof Johansson <olof@lixom.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
rtc: max77686: remove dead code for SMPL and WTSR

The MAX77686 RTC chip has two features called SMPL (Sudden Momentary
Power Loss) and WTSR (Watchdog Timeout and Software Resets).  Support
for these features seems to be implemented in the driver but compilation
is disabled using a C pre-processor conditional.

This code has been disabled since the driver was original merged in
commit fca1dd031a28 ("rtc: max77686: add Maxim 77686 driver").

So, since this code has never been built, let's just remove it.

Signed-off-by: Javier Martinez Canillas <javier.martinez@collabora.co.uk>
Reviewed-by: Krzysztof Kozlowski <k.kozlowski@samsung.com>
Cc: Doug Anderson <dianders@chromium.org>
Cc: Alessandro Zummo <a.zummo@towertech.it>
Cc: Olof Johansson <olof@lixom.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
rtc: max77686: fail to probe if no RTC regmap irqchip is set

The max77686 mfd driver adds a regmap IRQ chip which creates an IRQ
domain that is used to map the virtual RTC alarm1 interrupt.

The RTC driver assumes that this will always be true since the PMIC IRQ
is a required property according to the max77686 DT binding doc.  If an
"interrupts" property is not defined for a max77686 PMIC, then the mfd
probe function will fail and the RTC platform driver will never be
probed.

But even when it is not possible to probe the rtc-max77686 driver
without a regmap IRQ chip, it's better to explicitly check if the IRQ
chip data is not NULL and gracefully fail instead of getting an OOPS.

Signed-off-by: Javier Martinez Canillas <javier.martinez@collabora.co.uk>
Reported-by: Krzysztof Kozlowski <k.kozlowski@samsung.com>
Cc: Doug Anderson <dianders@chromium.org>
Cc: Alessandro Zummo <a.zummo@towertech.it>
Cc: Olof Johansson <olof@lixom.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
rtc: max77686: remove unneeded info log

If devm_rtc_device_register() fails a dev_err() is already reported so
there is no need to do an additional dev_info().

Signed-off-by: Javier Martinez Canillas <javier.martinez@collabora.co.uk>
Cc: Doug Anderson <dianders@chromium.org>
Cc: Krzysztof Kozlowski <k.kozlowski@samsung.com>
Cc: Alessandro Zummo <a.zummo@towertech.it>
Cc: Olof Johansson <olof@lixom.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
rtc: max77686: Use ffs() to calculate tm_wday

max77686_rtc_calculate_wday() is used to calculate the day of the week
to be filled in struct rtc_time but that function only calculates the
number of bits shifted.  So the ffs() function can be used to find the
first bit set instead of a special function.

[akpm@linux-foundation.org: add comment clarifying ffs() use]
Signed-off-by: Javier Martinez Canillas <javier.martinez@collabora.co.uk>
Cc: Joe Perches <joe@perches.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
rtc: add driver for Maxim 77802 PMIC Real-Time-Clock

The MAX7802 PMIC has a Real-Time-Clock (RTC) with two alarms.  This
patch adds support for the RTC and is based on a driver added by Simon
Glass to the Chrome OS kernel 3.8 tree.

[akpm@linux-foundation.org: add comment clarifying ffs() use]
Signed-off-by: Javier Martinez Canillas <javier.martinez@collabora.co.uk>
Reviewed-by: Krzysztof Kozlowski <k.kozlowski@samsung.com>
Cc: Doug Anderson <dianders@chromium.org>
Cc: Alessandro Zummo <a.zummo@towertech.it>
Cc: Olof Johansson <olof@lixom.net>
Cc: Simon Glass <sjg@chromium.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
drivers/rtc/rtc-pcf8563.c: fix uninitialized use warning

gcc-4.9 found a potential condition under which the 'pending' variable
may be used uninitialized:

  drivers/rtc/rtc-pcf8563.c: In function 'pcf8563_irq':
  drivers/rtc/rtc-pcf8563.c:173:5: warning: 'pending' may be used uninitialized in this function [-Wmaybe-uninitialized]

This is because in the pcf8563_get_alarm_mode() function, we check any
nonzero return of pcf8563_read_block_data, but in the irq function we
only check for negative values, so a possible positive value does not
get detected if the compiler chooses not to inline the entire call
chain.

Checking for any non-zero value in the interrupt handler as well is just
as correct and lets the compiler know what we are doing, without needing
a bogus initialization.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Cc: Sergei Shtylyov <sergei.shtylyov@cogentembedded.com>
Cc: Alessandro Zummo <a.zummo@towertech.it>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
drivers/rtc/rtc-pcf8563.c: fix pcf8563_irq() error return value

As pointed out by Sergei Shtylyov, the pcf8563_irq function contains a
bug in the error handling: an interrupt handler is not supposed to
return an errno value but an 'enum irqreturn'.

Let's fix this by returning IRQ_NONE in case of a communication error.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Cc: Sergei Shtylyov <sergei.shtylyov@cogentembedded.com>
Cc: Alessandro Zummo <a.zummo@towertech.it>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
drivers/rtc/rtc-rs5c372.c: use %*ph to dump small buffers

Instead of pushing each byte let's reduce stack usage by using %*ph specifier.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
drivers/rtc/Kconfig: Let several drivers depend on HAS_IOMEM to avoid compiling issue

Some drivers need 'devm_ioremap_resource' or 'devm_ioremap' which need
HAS_IOMEM, so let them depend on it.

The related error (with allmodconfig under score):

    MODPOST 1365 modules
  ERROR: "devm_ioremap_resource" [drivers/rtc/rtc-xgene.ko] undefined!
  ERROR: "devm_ioremap_resource" [drivers/rtc/rtc-stk17ta8.ko] undefined!
  ERROR: "devm_ioremap_resource" [drivers/rtc/rtc-ds1742.ko] undefined!
  ERROR: "devm_ioremap_resource" [drivers/rtc/rtc-ds1553.ko] undefined!
  ERROR: "devm_ioremap_resource" [drivers/rtc/rtc-ds1511.ko] undefined!
  ERROR: "devm_ioremap_resource" [drivers/rtc/rtc-ds1286.ko] undefined!
  ERROR: "devm_ioremap" [drivers/rtc/rtc-rp5c01.ko] undefined!
  ERROR: "devm_ioremap" [drivers/rtc/rtc-msm6242.ko] undefined!
  ERROR: "devm_ioremap" [drivers/rtc/rtc-m48t59.ko] undefined!
  ERROR: "devm_ioremap" [drivers/rtc/rtc-m48t35.ko] undefined!
  ERROR: "devm_ioremap" [drivers/rtc/rtc-bq4802.ko] undefined!

Signed-off-by: Chen Gang <gang.chen.5i5j@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
rtc-cmos: fix wakeup from S5 without CONFIG_PM_SLEEP

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 <daniel-gl@gmx.net>
Cc: Mika Westerberg <mika.westerberg@linux.intel.com>
Cc: Alessandro Zummo <a.zummo@towertech.it>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
fs/befs/btree.c: remove typedef befs_btree_node

The Linux kernel coding style guidelines suggest not using typedefs for
structure types.  This patch gets rid of the typedef for befs_btree_node.

The following Coccinelle semantic patch detects the case.

@tn1@
type td;
@@

typedef struct { ... } td;

@script:python tf@
td << tn1.td;
tdres;
@@

coccinelle.tdres = td;

@@
type tn1.td;
identifier tf.tdres;
@@

-typedef
 struct
+  tdres
   { ... }
-td
 ;

@@
type tn1.td;
identifier tf.tdres;
@@

-td
+ struct tdres

Signed-off-by: Himangi Saraogi <himangi774@gmail.com>
Acked-by: Julia Lawall <julia.lawall@lip6.fr>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
nilfs2: add missing blkdev_issue_flush() to nilfs_sync_fs()

Under normal circumstances nilfs_sync_fs() writes out the super block,
which causes a flush of the underlying block device.  But this depends
on the THE_NILFS_SB_DIRTY flag, which is only set if the pointer to the
last segment crosses a segment boundary.  So if only a small amount of
data is written before the call to nilfs_sync_fs(), no flush of the
block device occurs.

In the above case an additional call to blkdev_issue_flush() is needed.
To prevent unnecessary overhead, the new flag nilfs->ns_flushed_device
is introduced, which is cleared whenever new logs are written and set
whenever the block device is flushed.  For convenience the function
nilfs_flush_device() is added, which contains the above logic.

Signed-off-by: Andreas Rohner <andreas.rohner@gmx.net>
Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
nilfs2: improve the performance of fdatasync()

Support for fdatasync() has been implemented in NILFS2 for a long time,
but whenever the corresponding inode is dirty the implementation falls
back to a full-flegded sync().  Since every write operation has to
update the modification time of the file, the inode will almost always
be dirty and fdatasync() will fall back to sync() most of the time.  But
this fallback is only necessary for a change of the file size and not
for a change of the various timestamps.

This patch adds a new flag NILFS_I_INODE_SYNC to differentiate between
those two situations.

 * If it is set the file size was changed and a full sync is necessary.
 * If it is not set then only the timestamps were updated and
   fdatasync() can go ahead.

There is already a similar flag I_DIRTY_DATASYNC on the VFS layer with
the exact same semantics.  Unfortunately it cannot be used directly,
because NILFS2 doesn't implement write_inode() and doesn't clear the VFS
flags when inodes are written out.  So the VFS writeback thread can
clear I_DIRTY_DATASYNC at any time without notifying NILFS2.  So
I_DIRTY_DATASYNC has to be mapped onto NILFS_I_INODE_SYNC in
nilfs_update_inode().

Signed-off-by: Andreas Rohner <andreas.rohner@gmx.net>
Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
fs/hfs/hfs_fs.h: remove redundant sys_tz declaration

sys_tz is already declared in include/linux/time.h

Signed-off-by: Fabian Frederick <fabf@skynet.be>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
fs/ufs/balloc.c: remove unused variable

ucg is defined and set in ufs_bitmap_search but never used.

Signed-off-by: Fabian Frederick <fabf@skynet.be>
Cc: Evgeniy Dushistov <dushistov@mail.ru>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
fs/reiserfs/journal.c: fix sparse context imbalance warning

Merge conditional unlock/lock in the same condition to avoid sparse
warning:

  fs/reiserfs/journal.c:703:36: warning: context imbalance in 'add_to_chunk' - unexpected unlock

Signed-off-by: Fabian Frederick <fabf@skynet.be>
Cc: Jeff Mahoney <jeffm@suse.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
fat: remove redundant sys_tz declaration

sys_tz is already declared extern struct in include/linux/time.h

Signed-off-by: Fabian Frederick <fabf@skynet.be>
Cc: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
signal: use BUILD_BUG() instead of _NSIG_WORDS_is_unsupported_size()

Kill _NSIG_WORDS_is_unsupported_size(), use BUILD_BUG() instead.  This
simplifies the code, avoids the nested-externs warnings, and this way we
do not defer the problem to linker.

Also, fix the indentation in _SIG_SET_BINOP() and _SIG_SET_OP().

Note: this patch assumes that the code like "if (0) BUILD_BUG();" is
valid.  If not (say __compiletime_error() is not defined and thus
__compiletime_error_fallback() uses a negative array) we should fix
BUILD_BUG() and/or BUILD_BUG_ON_MSG().  This code should be fine by
definition, this is the documented purpose of BUILD_BUG().

[sfr@canb.auug.org.au: fix powerpc build failures]
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Reported-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
Reviewed-by: Josh Triplett <josh@joshtriplett.org>
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
coredump: add %i/%I in core_pattern to report the tid of the crashed thread

format_corename() can only pass the leader's pid to the core handler,
but there is no simple way to figure out which thread originated the
coredump.

As Jan explains, this also means that there is no simple way to create
the backtrace of the crashed process:

As programs are mostly compiled with implicit gcc -fomit-frame-pointer
one needs program's .eh_frame section (equivalently PT_GNU_EH_FRAME
segment) or .debug_frame section.  .debug_frame usually is present only
in separate debug info files usually not even installed on the system.
While .eh_frame is a part of the executable/library (and it is even
always mapped for C++ exceptions unwinding) it no longer has to be
present anywhere on the disk as the program could be upgraded in the
meantime and the running instance has its executable file already
unlinked from disk.

One possibility is to echo 0x3f >/proc/*/coredump_filter and dump all
the file-backed memory including the executable's .eh_frame section.
But that can create huge core files, for example even due to mmapped
data files.

Other possibility would be to read .eh_frame from /proc/PID/mem at the
core_pattern handler time of the core dump.  For the backtrace one needs
to read the register state first which can be done from core_pattern
handler:

    ptrace(PTRACE_SEIZE, tid, 0, PTRACE_O_TRACEEXIT)
    close(0);    // close pipe fd to resume the sleeping dumper
    waitpid();   // should report EXIT
    PTRACE_GETREGS or other requests

The remaining problem is how to get the 'tid' value of the crashed
thread.  It could be read from the first NT_PRSTATUS note of the core
file but that makes the core_pattern handler complicated.

Unfortunately %t is already used so this patch uses %i/%I.

Automatic Bug Reporting Tool (https://github.com/abrt/abrt/wiki/overview)
is experimenting with this.  It is using the elfutils
(https://fedorahosted.org/elfutils/) unwinder for generating the
backtraces.  Apart from not needing matching executables as mentioned
above, another advantage is that we can get the backtrace without saving
the core (which might be quite large) to disk.

[mmilata@redhat.com: final paragraph of changelog]
Signed-off-by: Jan Kratochvil <jan.kratochvil@redhat.com>
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Jan Kratochvil <jan.kratochvil@redhat.com>
Cc: Mark Wielaard <mjw@redhat.com>
Cc: Martin Milata <mmilata@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>