Use sizeof where possible to ensure we don't read/write more than the
allocated buffer.
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>

ds1307->regs is never used before being read or initialized locally. There
is no point in keeping a copy in memory.

Also limit the size of the read buffer to what is really used, rename buf
to regs for consistency and use sizeof() where possible.
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>

Based on QNAP's arch/arm/mach-rtk119x/driver/rtk_rtc_drv.c code and
mach-rtk119x/driver/dc2vo/fpga/include/mis_reg.h register definitions.

The base year 2014 was observed on all of Zidoo X9S, ProBox2 Ava and
Beelink Lake I.
Signed-off-by: Andreas Färber <afaerber@suse.de>
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>

Add a binding for the RTC on the Realtek RTD119x/RTD129x SoC families.
Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Andreas Färber <afaerber@suse.de>
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>

The RTC can output its 32kHz clock outside of the SoC, for example to clock
a WiFi chip.

Create a new clock that other devices will be able to retrieve, while
maintaining the DT stability by providing a default name for that clock if
clock-output-names doesn't list one.
Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>

Add device driver for a virtual RTC device in Android emulator.

The compatible string used by OS for binding the driver is defined
as "google,goldfish-rtc".
Signed-off-by: Miodrag Dinic <miodrag.dinic@imgtec.com>
Signed-off-by: Goran Ferenc <goran.ferenc@imgtec.com>
Signed-off-by: Aleksandar Markovic <aleksandar.markovic@imgtec.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>

Add documentation for DT binding of Goldfish RTC driver. The compatible
string used by OS for binding the driver is "google,goldfish-rtc".
Signed-off-by: Miodrag Dinic <miodrag.dinic@imgtec.com>
Signed-off-by: Goran Ferenc <goran.ferenc@imgtec.com>
Signed-off-by: Aleksandar Markovic <aleksandar.markovic@imgtec.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>

This adds support for reading and writing date/time from/to ds1341 chip.

ds1341 chip has other features - alarms, input clock (can be used instead
of intercal oscillator for better accuracy), output clock ("square wave
generation"). However, not all of that is available at the same time.
Same chip pins, CLKIN/nINTA and SQW/nINTB, can be used either for
input/output clocks, or for alarm interrupts. Role of these pins on
particular board depends on hardware wiring.

We can add device tree properties that describe if each of pins is wired
as clock, or as interrupt, or left unconnected, and enable support for
corresponding functionality based on that. But that is cumbersome, requires
hardware for testing, and has to deal with bit enabling/disabling output
clock also affects which pins alarm interrupts are routed to.

Another factor is that there are hardware setups (i.e. ZII RDU2) that
power DS1341 from SuperCap, which makes power saving critical. For such
setups, kernel driver should leave register bits that control mentioned
pins in the state configured by bootloader.

Given all that, it was decided to limit support to "only date/time" for
now. That is enough for common use case. Full (and cumbersome)
implementation can be added later if ever needed.
Signed-off-by: Nikita Yushchenko <nikita.yoush@cogentembedded.com>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Tested-by: Aleksander Morgado <aleksander@aleksander.es>
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>

Remove member nvram_offset from struct ds1307 and use the value stored
in struct chip_desc directly.
Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>

Factor out offset to struct chip_desc and remove it from struct ds1307.
Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>

Factor out rtc_ops to struct chip_desc and use ds13xx_rtc_ops as default.
Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>

Factor out irq_handler to struct chip_desc and use ds1307_irq as default.
Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>

Change the usage of variable want_irq to reflect its name. Don't set
it to true in case wakeup is enabled but no interrupt number is given.
In addition set variable ds1307_can_wakeup_device if chip->alarm
is set only.
This allows to simplify the code and make it better understandable.
Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>

Constify struct chip_desc variables.
Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>

Instead of storing the trickle_charger_setup value in struct chip_desc
we can let function ds1307_trickle_init return it because it's used
in the probe function only.
This allows us to constify struct chip_desc variables in a next step.
Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>

Factor out the bbsqi bit to struct chip_desc.
Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>

The irq number is used in the probe function only, so we don't have
to store it in struct ds1307.
Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>

The RK808 and RK805 PMICs are using a similar register map.
We can reuse the rtc driver for the RK805 PMIC. So let's add
the RK805 in the Kconfig description.
Signed-off-by: Elaine Zhang <zhangqing@rock-chips.com>
Signed-off-by: Joseph Chen <chenjh@rock-chips.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>

i2c_device_id are not supposed to change at runtime. All functions
working with i2c_device_id provided by <linux/i2c.h> work with
const i2c_device_id. So mark the non-const structs as const.
Signed-off-by: Arvind Yadav <arvind.yadav.cs@gmail.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>

There are no driver left using .open and .release. There is no good use
case for them as there is nothing the character device interface does that
should not be done in the sysfs interface or in-kernel interface.

Remove those callbacks now to avoid future confusion.
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>

Currently, the IRQs are disabled when the rtc character device is closed.
This means that the device needs to stay open to get alarms while the usual
use case will open the device, set the alarm and close the device as is
done in rtcwake.

Keep the alarm functional on character device release so the platform can
actually wakeup.
Reviewed-by: Fabio Estevam <fabio.estevam@nxp.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>

Currently, the IRQs are disabled when the rtc character device is closed.
This means that the device needs to stay open to get alarms while the usual
use case will open the device, set the alarm and close the device.

Keep the alarms functional on character device release. Note that the PIE
are never enabled and would anyway be disabled by the core.
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>

Currently, the driver unregisters the IRQs when the rtc character device is
closed. This means that the device needs to stay open to get alarms while
the usual use case will open the device, set the alarm and close the
device.

Move the IRQ requests to sa1100_rtc_probe() and use the devm managed
versions so we don't need to free them.
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>

In the error path of sa1100_rtc_open(), info->clk is disabled which will
happen again in sa1100_rtc_remove() when the module is removed whereas it
is only enabled once in sa1100_rtc_init().

Fixes: 0cc0c38e ("drivers/rtc/rtc-sa1100.c: move clock enable/disable to probe/remove")
Acked-by: Robert Jarzmik <robert.jarzmik@free.fr>
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>

pxa_rtc_open() registers the interrupt handler which will access the RTC
registers. However, pxa_rtc_open() is called before the register range is
ioremapped. Instead, call it after devm_ioremap().
Acked-by: Robert Jarzmik <robert.jarzmik@free.fr>
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>

The last remaining sysfs attribute is undocumented and useless as it can
only be used to debug the driver. Remove it.
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>

Don't require an IRQ if the wakeup-source device-tree property is present.
Signed-off-by: Eric Cooper <ecc@cmu.edu>
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>

Currently, the driver unregisters the IRQs when the rtc character device is
closed. This means that the device needs to stay open to get alarms while
the usual use case will open the device, set the alarm and close the
device.

Move the IRQ requests to puv3_rtc_probe() and use the devm managed versions
so we don't need to free them.
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>

Use managed RTC device allocation as this allows for further cleanup.
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>

The check on ret < 0 is redundant as the goto destination is the
next statment.  Remove this redudant check and goto.

Detected by CoverityScan, CID#1268785 ("Identical code for different
branches")
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>

There are two error return paths that do not kfree clk_data and
we end up with a memory leak. Fix these with a kfree error exit
path.

Detected by CoverityScan, CID#1402959 ("Resource Leak")
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>

Remove double init of spinlock in sun6i_rtc_clk_init()

Fixes: 847b8bf62eb4 ("rtc: sun6i: Expose the 32kHz oscillator")
Signed-off-by: Alexey Klimov <alexey.klimov@arm.com>
Reviewed-by: Chen-Yu Tsai <wens@csie.org>
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>

Commit 8b44f5be ("ARM: dts: armada: replace isil,irq2-can-wakeup-machine with wakeup-source property")
removed the last usage of "isil,irq2-can-wakeup-machine" almost
two years ago. So I think we can get rid of supporting this
legacy binding.
Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>

Implements RTC_VL_READ and RTC_VL_CLR ioctls.
Signed-off-by: Fabien Lahoudere <fabien.lahoudere@collabora.co.uk>
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>

If RTC time have been altered by low voltage, we notify users
that RTC time is invalid by returning -EINVAL.
The RTC time needs to be set correctly to clear the invalid flag.
Signed-off-by: Fabien Lahoudere <fabien.lahoudere@collabora.co.uk>
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>

Pull documentation format standardization from Jonathan Corbet:
 "This series converts a number of top-level documents to the RST format
  without incorporating them into the Sphinx tree. The hope is to bring
  some uniformity to kernel documentation and, perhaps more importantly,
  have our existing docs serve as an example of the desired formatting
  for those that will be added later.

  Mauro has gone through and fixed up a lot of top-level documentation
  files to make them conform to the RST format, but without moving or
  renaming them in any way. This will help when we incorporate the ones
  we want to keep into the Sphinx doctree, but the real purpose is to
  bring a bit of uniformity to our documentation and let the top-level
  docs serve as examples for those writing new ones"

* tag 'standardize-docs' of git://git.lwn.net/linux: (84 commits)
  docs: kprobes.txt: Fix whitespacing
  tee.txt: standardize document format
  cgroup-v2.txt: standardize document format
  dell_rbu.txt: standardize document format
  zorro.txt: standardize document format
  xz.txt: standardize document format
  xillybus.txt: standardize document format
  vfio.txt: standardize document format
  vfio-mediated-device.txt: standardize document format
  unaligned-memory-access.txt: standardize document format
  this_cpu_ops.txt: standardize document format
  svga.txt: standardize document format
  static-keys.txt: standardize document format
  smsc_ece1099.txt: standardize document format
  SM501.txt: standardize document format
  siphash.txt: standardize document format
  sgi-ioc4.txt: standardize document format
  SAK.txt: standardize document format
  rpmsg.txt: standardize document format
  robust-futexes.txt: standardize document format
  ...

Pull random updates from Ted Ts'o:
 "Add wait_for_random_bytes() and get_random_*_wait() functions so that
  callers can more safely get random bytes if they can block until the
  CRNG is initialized.

  Also print a warning if get_random_*() is called before the CRNG is
  initialized. By default, only one single-line warning will be printed
  per boot. If CONFIG_WARN_ALL_UNSEEDED_RANDOM is defined, then a
  warning will be printed for each function which tries to get random
  bytes before the CRNG is initialized. This can get spammy for certain
  architecture types, so it is not enabled by default"

* tag 'random_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/random:
  random: reorder READ_ONCE() in get_random_uXX
  random: suppress spammy warnings about unseeded randomness
  random: warn when kernel uses unseeded randomness
  net/route: use get_random_int for random counter
  net/neighbor: use get_random_u32 for 32-bit hash random
  rhashtable: use get_random_u32 for hash_rnd
  ceph: ensure RNG is seeded before using
  iscsi: ensure RNG is seeded before use
  cifs: use get_random_u32 for 32-bit lock random
  random: add get_random_{bytes,u32,u64,int,long,once}_wait family
  random: add wait_for_random_bytes() API

Pull ->s_options removal from Al Viro:
 "Preparations for fsmount/fsopen stuff (coming next cycle). Everything
  gets moved to explicit ->show_options(), killing ->s_options off +
  some cosmetic bits around fs/namespace.c and friends. Basically, the
  stuff needed to work with fsmount series with minimum of conflicts
  with other work.

  It's not strictly required for this merge window, but it would reduce
  the PITA during the coming cycle, so it would be nice to have those
  bits and pieces out of the way"

* 'work.mount' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  isofs: Fix isofs_show_options()
  VFS: Kill off s_options and helpers
  orangefs: Implement show_options
  9p: Implement show_options
  isofs: Implement show_options
  afs: Implement show_options
  affs: Implement show_options
  befs: Implement show_options
  spufs: Implement show_options
  bpf: Implement show_options
  ramfs: Implement show_options
  pstore: Implement show_options
  omfs: Implement show_options
  hugetlbfs: Implement show_options
  VFS: Don't use save/replace_mount_options if not using generic_show_options
  VFS: Provide empty name qstr
  VFS: Make get_filesystem() return the affected filesystem
  VFS: Clean up whitespace in fs/namespace.c and fs/super.c
  Provide a function to create a NUL-terminated string from unterminated data

Pull more __copy_.._user elimination from Al Viro.

* 'work.__copy_to_user' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  drm_dp_aux_dev: switch to read_iter/write_iter