The WM831x series of PMICs contain RTC functionality. The hardware
provides a 32 bit counter incrementing at 1Hz together with a per
tick interrupt and an alarm value. For simplicity the driver chooses
to define the epoch for the counter as the Unix epoch - if required
platform data can be used in future to customise this.

When powered on from a completely cold state the RTC reports that it
has not been configured - when this happens an error is returned
when attempting to read the RTC in order to avoid use of values we
know to be invalid.

The hardware also provides security features which mean that it can
ignore attempts to set the RTC time in certain circumstances, most
notably if the RTC is written to too often. These errors are detected
by verifying the written RTC value.
Signed-off-by: NMark Brown <broonie@opensource.wolfsonmicro.com>
Acked-by: NAlessandro Zummo <a.zummo@towertech.it>
Signed-off-by: NSamuel Ortiz <sameo@linux.intel.com>

Add support for the Epson RX-8025SA/NB RTC chips.  It includes support for
alarms, periodic interrupts (1 Hz) and clock precision adjustment.

For clock precision adjustment, the SYSFS file "clock_adjust_ppb" gets
created in "/sys/class/rtc/rtcX/device".  It permits to set and get the
clock adjustment in ppb (parts per billion), e.g.:

  # echo -183000 > /sys/class/rtc/rtc0/device/clock_adjust_ppb
  # cat /sys/class/rtc/rtc0/device/clock_adjust_ppb
  -183000

This allows to compensate temperature dependent clock drifts.  According
to the RX8025 SA/NB application manual the frequency and temperature
characteristics can be approximated using the following equation:

  df = a * (ut - t)**2

  df: Frequency deviation in any temperature
  a : Coefficient = (-35 +-5) * 10**-9
  ut: Ultimate temperature in degree = +25 +-5 degree
  t : Any temperature in degree
Signed-off-by: NWolfgang Grandegger <wg@grandegger.com>
Signed-off-by: NSergei Poselenov <sposelenov@emcraft.com>
Signed-off-by: NYuri Tikhonov <yur@emcraft.com>
Signed-off-by: NDmitry Rakhchev <rda@emcraft.com>
Signed-off-by: NMatthias Fuchs <matthias.fuchs@esd.eu>
Acked-by: NJean Delvare <khali@linux-fr.org>
Signed-off-by: NAlessandro Zummo <a.zummo@towertech.it>
Cc: David Brownell <david-b@pacbell.net>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

This adds rtc-generic support for SUPERH32.
Signed-off-by: NPaul Mundt <lethal@linux-sh.org>

This adds clock framework support to the rtc-sh driver. With this in
place, platforms can default to leaving the clock disabled rather than
placing it in the always enabled state.
Signed-off-by: NPaul Mundt <lethal@linux-sh.org>

Compared to the other supported chips, the m41t62 uses a different
register to set the square wave frequency.
Signed-off-by: NDaniel Glockner <dg@emlix.com>
Cc: Chris Zankel <chris@zankel.net>
Cc: David Brownell <david-b@pacbell.net>
Cc: Alessandro Zummo <a.zummo@towertech.it>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Create a real RTC driver for PS3, and unhook the deprecated
ppc_md.[gs]et_rtc_time.
Signed-off-by: NGeert Uytterhoeven <Geert.Uytterhoeven@sonycom.com>
Acked-by: NAlessandro Zummo <a.zummo@towertech.it>
Acked-by: NGeoff Levand <geoffrey.levand@am.sony.com>
Signed-off-by: NKyle McMartin <kyle@mcmartin.ca>

PowerPC has been a long time user of the generic RTC abstraction, so hook up
rtc-generic:
  - Create the "rtc-generic" platform device if ppc_md.get_rtc_time is set,
  - Kill rtc-ppc, as rtc-generic offers the same functionality in a more
    generic way, and supports autoloading through udev.
Signed-off-by: NGeert Uytterhoeven <Geert.Uytterhoeven@sonycom.com>
Acked-by: NDavid Woodhouse <David.Woodhouse@intel.com>
Acked-by: NAlessandro Zummo <a.zummo@towertech.it>
Acked-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: NKyle McMartin <kyle@mcmartin.ca>

m68k has been a long time user of the generic RTC abstraction, so hook up
rtc-generic:
  - Create the "rtc-generic" platform device if mach_hwclk is set,
  - Add checks for mach_hwclk, in anticipation of RTC chip drivers being moved
    to drivers/rtc/.
Signed-off-by: NGeert Uytterhoeven <Geert.Uytterhoeven@sonycom.com>
Acked-by: NAlessandro Zummo <a.zummo@towertech.it>
Signed-off-by: NKyle McMartin <kyle@mcmartin.ca>

The rtc-parisc driver is not PA-RISC specific at all, as it uses the existing
(but deprecated) generic RTC infrastructure ([gs]et_rtc_time()).
Rename the driver from rtc-parisc to rtc-generic.
Signed-off-by: NGeert Uytterhoeven <Geert.Uytterhoeven@sonycom.com>
Acked-by: NAlessandro Zummo <a.zummo@towertech.it>
Signed-off-by: NKyle McMartin <kyle@mcmartin.ca>

Add support for the EPSON RX8025 RTC.  The date/time registers of this
chip are compatible with the DS1307.
Signed-off-by: NMatthias Fuchs <matthias.fuchs@esd-electronics.com>
Signed-off-by: NAlessandro Zummo <a.zummo@towertech.it>
Cc: David Brownell <david-b@pacbell.net>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Munge Stephane Eranian's efirtc.c code into an rtc platform driver

[akpm@linux-foundation.org: use is_leap_year()]
Signed-off-by: Ndann frazier <dannf@hp.com>
Cc: Alessandro Zummo <alessandro.zummo@towertech.it>
Cc: stephane eranian <eranian@googlemail.com>
Cc: "Luck, Tony" <tony.luck@intel.com>
Cc: David Brownell <david-b@pacbell.net>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Simple RTC driver for the MSP430 firmware on the DM355 EVM board.  Other
than not supporting atomic reads/writes of all four bytes, this is
reasonable as a basic no-alarm RTC.
Signed-off-by: NDavid Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: NKevin Hilman <khilman@deeprootsystems.com>
Acked-by: NAlessandro Zummo <a.zummo@towertech.it>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Signed-off-by: NBalaji Rao <balajirrao@openmoko.org>
Cc: Andy Green <andy@openmoko.com>
Acked-by: NAlessandro Zummo <a.zummo@towertech.it>
Cc: Paul Gortmaker <a.zummo@towertech.it>
Cc: rtc-linux@googlegroups.com
Signed-off-by: NSamuel Ortiz <sameo@openedhand.com>

Driver for the on-chip RTC found in some of Marvell's SoCs such as the
Kirkwood 88F6281 and 88F6192 devices.
Signed-off-by: NSaeed Bishara <saeed@marvell.com>
Signed-off-by: NLennert Buytenhek <buytenh@marvell.com>
Signed-off-by: NNicolas Pitre <nico@marvell.com>
Signed-off-by: NAlessandro Zummo <a.zummo@towertech.it>
Cc: David Brownell <david-b@pacbell.net>
Cc: Russell King <rmk@arm.linux.org.uk>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Add support for RTC in TX4939 SoC.
Signed-off-by: NAtsushi Nemoto <anemo@mba.ocn.ne.jp>
Acked-by: NAlessandro Zummo <a.zummo@towertech.it>
Cc: David Brownell <david-b@pacbell.net>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Simple driver which uses the Au1xxx Time-Of-Year counter (counter0)
as a 1Hz RTC.

[akpm@linux-foundation.org: repair Kconfig]
Signed-off-by: NManuel Lauss <mano@roarinelk.homelinux.net>
Acked-by: NAlessandro Zummo <a.zummo@towertech.it>
Cc: David Brownell <david-b@pacbell.net>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Remove double spaces and adds some suggestions.  It also fixes the
descriptions of options that are no more available as modules.
Signed-off-by: NAlessandro Zummo <a.zummo@towertech.it>
Cc: David Brownell <david-b@pacbell.net>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Small fixes for the ds1390 driver

 - fixed initialization of the spi device
 - added missing includes
 - removed printks
 - removed useless wrappers for rtc ops
 - removed dead code
Signed-off-by: NAlessandro Zummo <a.zummo@towertech.it>
Cc: Mark Jackson <mpfj@mimc.co.uk>
Cc: David Brownell <david-b@pacbell.net>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

With PXA27x and above, a new RTC hardware block was added in addition to
the legacy one which is also found on the SA1100 SOC family.  This second
RTC block is called "wristwatch" and "periodic interrupt" and works
independently from the other RTC block.

The driver offers provides :
 - a 1Hz ticking clock
 - a periodic alarm, in the 1Hz to 1000Hz range
 - a one shot alarm
Signed-off-by: NRobert Jarzmik <robert.jarzmik@free.fr>
Cc: Jonathan Cameron <jic23@cam.ac.uk>
Signed-off-by: NAlessandro Zummo <a.zummo@towertech.it>
Cc: David Brownell <david-b@pacbell.net>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Add standard interfaces for alarm/update irqs enabling.  Drivers are no
more required to implement equivalent ioctl code as rtc-dev will provide
it.

UIE emulation should now be handled correctly and will work even for those
RTC drivers who cannot be configured to do both UIE and AIE.
Signed-off-by: NAlessandro Zummo <a.zummo@towertech.it>
Cc: David Brownell <david-b@pacbell.net>
Cc: Atsushi Nemoto <anemo@mba.ocn.ne.jp>
Cc: Ralf Baechle <ralf@linux-mips.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Add support for the Dallas DS1390/93/94 SPI RTC chip.
Signed-off-by: NMark Jackson <mpfj@mimc.co.uk>
Acked-by: NAlessandro Zummo <a.zummo@towertech.it>
Cc: David Brownell <david-b@pacbell.net>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Provide the basic "get" and "set" functionality for the Epson RX-8581 I2C
RTC.  It currently does not support the RTC's Alarm or Fixed-cycle timer.

[akpm@linux-foundation.org: need log2.h for ilog2(), remove unneeded initialisation]
Signed-off-by: NMartyn Welch <martyn.welch@gefanuc.com>
Signed-off-by: NAlessandro Zummo <a.zummo@towertech.it>
Cc: David Brownell <david-b@pacbell.net>
Cc: Jean Delvare <khali@linux-fr.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

This adds support for the RTC provided by the Wolfson Microelectronics
WM8350.

This driver was originally written by Graeme Gregory and Liam Girdwood,
though it has been modified since then to update it to current mainline
coding standards and for API completeness.

[akpm@linux-foundation.org: s/schedule_timeout_interruptible/schedule_timeout_uninterruptible/ to prevent bogus timeout when signal_pending()]
Signed-off-by: NMark Brown <broonie@opensource.wolfsonmicro.com>
Cc: Alessandro Zummo <a.zummo@towertech.it>
Cc: David Brownell <david-b@pacbell.net>
Cc: Liam Girdwood <linux@wolfsonmicro.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

This adds a driver for the RTC inside the TWL4030 multi-function device.
It's a fairly basic RTC, with a wake-capable alarm.

Note that many of the pre-release Overo boards now in circulation can't
effectively use this RTC, because of a wiring error that puts its TWL
chip into "secure" mode.  (As in "secure yourself against tampering".)
This isn't an issue on other OMAP3 boards now supported in mainline,
such as Beagle and Labrador.
Signed-off-by: NDavid Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: NTony Lindgren <tony@atomide.com>
Acked-by: NAlessandro Zummo <a.zummo@towertech.it>
Signed-off-by: NSamuel Ortiz <sameo@openedhand.com>

This was accidentally left out when the R2025S/D support was merged
earlier.
Signed-off-by: NPaul Mundt <lethal@linux-sh.org>

Add support for M41T65 Real Time Clock chip.

The main differences I see between the M41T65 and M41T80 are that:

1) The M41T65 watchdog timer has three bits controlling resolution
   (versus two for the M41T80).

2) There is no register 0x13 for controlling square-wave output.
Signed-off-by: NSteven A. Falco <sfalco@harris.com>
Acked-by: NAlessandro Zummo <a.zummo@towertech.it>
Cc: "Maciej W. Rozycki" <macro@linux-mips.org>
Acked-by: NAtsushi Nemoto <anemo@mba.ocn.ne.jp>
Cc: David Brownell <david-b@pacbell.net>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Now that arch/ppc is dead CONFIG_PPC_MERGE is always defined for all
powerpc platforms and we want to get rid of it use CONFIG_PPC instead.
Signed-off-by: NKumar Gala <galak@kernel.crashing.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: David Brownell <david-b@pacbell.net>
Cc: Alessandro Zummo <a.zummo@towertech.it>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Add support for the Dallas DS3234 chip - extremely accurate SPI bus RTC
with integrated crystal and SRAM.

[akpm@linux-foundation.org: don't use BIN2BCD/BCD2BIN]
Signed-off-by: NDennis Aberilla <denzzzhome@yahoo.com>
Signed-off-by: NAlessandro Zummo <a.zummo@towertech.it>
Cc: David Brownell <david-b@pacbell.net>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

This driver replaces the broken ip27-rtc driver in drivers/char and
gives back RTC support for SGI IP27 machines.
Signed-off-by: NThomas Bogendoerfer <tsbogend@alpha.franken.de>
Acked-by: NAlessandro Zummo <alessandro.zummo@towertech.it>
Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

This driver replaces the broken DS1286 driver in drivers/char and gives back
RTC support for SGI IP22 and IP28 machines.
Signed-off-by: NThomas Bogendoerfer <tsbogend@alpha.franken.de>
Acked-by: NAlessandro Zummo <alessandro.zummo@towertech.it>
Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

Signed-off-by: NKyle McMartin <kyle@mcmartin.ca>

Fix for linux-next's

: Author: David S. Miller <davem@davemloft.net>  2008-08-28 19:54:17
: Committer: David S. Miller <davem@davemloft.net>  2008-08-29 14:16:45
: Parent: 7f604599 (Blackfin RTC Driver: BF561 not have on-chip RTC)
: Child:  cca4c231 (rtc: Add TI BQ4802 RTC driver.)
: Branches: git-alsa-tiwai, linux-next
: Follows: v2.6.27-rc4
: Precedes: next-20080902
: 
:     rtc: Allow RTC_DRV_CMOS to be used on SPARC.


In file included from drivers/rtc/rtc-cmos.c:40:
include/asm-generic/rtc.h: In function 'rtc_is_updating':
include/asm-generic/rtc.h:40: error: 'rtc_port' undeclared (first use in this function)
include/asm-generic/rtc.h:40: error: (Each undeclared identifier is reported only once
include/asm-generic/rtc.h:40: error: for each function it appears in.)
include/asm-generic/rtc.h: In function 'get_rtc_time':
include/asm-generic/rtc.h:73: error: 'rtc_port' undeclared (first use in this function)
include/asm-generic/rtc.h: In function 'set_rtc_time':
include/asm-generic/rtc.h:160: error: 'rtc_port' undeclared (first use in this function)
drivers/rtc/rtc-cmos.c: In function 'cmos_read_alarm':
drivers/rtc/rtc-cmos.c:193: error: 'rtc_port' undeclared (first use in this function)
drivers/rtc/rtc-cmos.c: In function 'cmos_checkintr':
drivers/rtc/rtc-cmos.c:255: error: 'rtc_port' undeclared (first use in this function)
drivers/rtc/rtc-cmos.c: In function 'cmos_irq_enable':
drivers/rtc/rtc-cmos.c:272: error: 'rtc_port' undeclared (first use in this function)
drivers/rtc/rtc-cmos.c: In function 'cmos_irq_disable':
drivers/rtc/rtc-cmos.c:292: error: 'rtc_port' undeclared (first use in this function)
drivers/rtc/rtc-cmos.c: In function 'cmos_set_alarm':
drivers/rtc/rtc-cmos.c:337: error: 'rtc_port' undeclared (first use in this function)
drivers/rtc/rtc-cmos.c: In function 'cmos_irq_set_freq':
drivers/rtc/rtc-cmos.c:378: error: 'rtc_port' undeclared (first use in this function)
drivers/rtc/rtc-cmos.c: In function 'cmos_procfs':
drivers/rtc/rtc-cmos.c:455: error: 'rtc_port' undeclared (first use in this function)
drivers/rtc/rtc-cmos.c: In function 'cmos_nvram_read':
drivers/rtc/rtc-cmos.c:519: error: 'rtc_port' undeclared (first use in this function)
drivers/rtc/rtc-cmos.c: In function 'cmos_nvram_write':
drivers/rtc/rtc-cmos.c:551: error: 'rtc_port' undeclared (first use in this function)
drivers/rtc/rtc-cmos.c: In function 'cmos_interrupt':
drivers/rtc/rtc-cmos.c:588: error: 'rtc_port' undeclared (first use in this function)
drivers/rtc/rtc-cmos.c: In function 'cmos_do_probe':
drivers/rtc/rtc-cmos.c:722: error: 'rtc_port' undeclared (first use in this function)
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Add support for two compatible RTC:
- M48T08 which does not have alarm part,
- M48T08 which does not have alarm part and has
  only 2KB of NVRAM

These types covers all Mostek's RTC used in Sun UltraSparc workstations.

Tested on Sun Ultra60 with M48T59 RTC.
Signed-off-by: NKrzysztof Helt <krzysztof.h1@wp.pl>
Signed-off-by: NAlessandro Zummo <a.zummo@towertech.it>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Add Sparc to the Kconfig depends list.

Add __sparc___ to address_sparc = 128 ifdef.

Finally, don't be concerned about 24-hour BCD mode support if the RTC
doesn't have a valid IRQ.  We won't even use the alarm code in this
case and the Sparc RTCs have this limitation.
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Signed-off-by: NGraf Yang <graf.yang@analog.com>
Signed-off-by: NBryan Wu <cooloney@kernel.org>
Cc: Alessandro Zummo <a.zummo@towertech.it>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Support the Dallas/Maxim DS1305 and DS1306 RTC chips.  These use SPI, and
support alarms, NVRAM, and a trickle charger for use when their backup
power supply is a supercap or rechargeable cell.

This basic driver doesn't yet support suspend/resume or wakealarms.
Signed-off-by: NDavid Brownell <dbrownell@users.sourceforge.net>
Cc: Alessandro Zummo <a.zummo@towertech.it>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

This patch adds kernel driver for M41T94 RTC chip connected via SPI.
I've tested it on two different AT91-based hardwares.

This is third revision of the patch: some comments made by
Alessandro Zummo fixed.

Revision two added support for century bit and fixes.
Signed-off-by: NKim B. Heino <Kim.Heino@bluegiga.com>
Signed-off-by: NAlessandro Zummo <a.zummo@towertech.it>
Cc: David Brownell <david-b@pacbell.net>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>