Граф коммитов

38 Коммитов

Автор SHA1 Сообщение Дата
Bartosz Golaszewski 3a905c2d95 rtc: add devm_ prefix to rtc_nvmem_register()
rtc_nvmem_register() is a managed interface. It doesn't require any
release function to be called at driver detach. To avoid confusing
driver authors, let's rename it to devm_rtc_nvmem_register() and add it
to the list of managed interfaces in Documentation/.

Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Link: https://lore.kernel.org/r/20201109163409.24301-6-brgl@bgdev.pl
2020-11-19 12:50:11 +01:00
Alexandre Belloni 25ece30561 rtc: nvmem: remove nvram ABI
The nvram sysfs attributes have been deprecated at least since v4.13, more
than 3 years ago and nobody ever complained about the deprecation warning.

Remove the sysfs attributes now.

[Bartosz: remove the declaration of rtc_nvmem_unregister()]

Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
Link: https://lore.kernel.org/r/20201109163409.24301-5-brgl@bgdev.pl
2020-11-19 12:50:11 +01:00
Thomas Bogendoerfer 9f8010e71f rtc: ds1685: Fix bank switching to avoid endless loop
ds1685_rtc_begin_data_access() tried to access an extended register before
enabling access to it by switching to bank 1. Depending on content in NVRAM
this could lead to an endless loop. While at it fix also switch back to
bank 0 in ds1685_rtc_end_data_access().

Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Acked-by: Joshua Kinard <kumba@gentoo.org>
Link: https://lore.kernel.org/r/20200910084124.138560-1-tsbogend@alpha.franken.de
2020-09-15 11:24:29 +02:00
Alexandre Belloni 4ed3f1b8c4 rtc: ds1685: fix build error with make W=1
Fix the following parsing errors when building with W=1:
drivers/rtc/rtc-ds1685.c:1053: error: Cannot parse struct or union!
drivers/rtc/rtc-ds1685.c:1062: error: Cannot parse struct or union!
drivers/rtc/rtc-ds1685.c:1363: warning: cannot understand function prototype: 'struct platform_driver ds1685_rtc_driver = '

Cc: Joshua Kinard <kumba@gentoo.org>
Link: https://lore.kernel.org/r/20191122102212.400158-5-alexandre.belloni@bootlin.com
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
2019-11-27 09:31:13 +01:00
Alexandre Belloni 4740158044 rtc: ds1685: remove set but unused variables
Fix the following warnings:
drivers/rtc/rtc-ds1685.c: In function ‘ds1685_rtc_read_time’:
drivers/rtc/rtc-ds1685.c:264:5: warning: variable ‘ctrlb’ set but not used [-Wunused-but-set-variable]
  264 |  u8 ctrlb, century;
      |     ^~~~~
drivers/rtc/rtc-ds1685.c: In function ‘ds1685_rtc_proc’:
drivers/rtc/rtc-ds1685.c:758:19: warning: variable ‘ctrlc’ set but not used [-Wunused-but-set-variable]
  758 |  u8 ctrla, ctrlb, ctrlc, ctrld, ctrl4a, ctrl4b, ssn[8];
      |                   ^~~~~
Cc: Joshua Kinard <kumba@gentoo.org>
Acked-By: Joshua Kinard <kumba@gentoo.org>
Link: https://lore.kernel.org/r/20191122102212.400158-4-alexandre.belloni@bootlin.com
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
2019-11-27 09:31:13 +01:00
Thomas Bogendoerfer 299b610117 rtc: ds1685: add indirect access method and remove plat_read/plat_write
SGI Octane (IP30) doesn't have RTC register directly mapped into CPU
address space, but accesses RTC registers with an address and data
register.  This is now supported by additional access functions, which
are selected by a new field in platform data. Removed plat_read/plat_write
since there is no user and their usage could introduce lifetime issue,
when functions are placed in different modules.

Signed-off-by: Thomas Bogendoerfer <tbogendoerfer@suse.de>
Acked-by: Joshua Kinard <kumba@gentoo.org>
Reviewed-by: Joshua Kinard <kumba@gentoo.org>
Link: https://lore.kernel.org/r/20191014214621.25257-1-tbogendoerfer@suse.de
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
2019-10-16 10:39:00 +02:00
Thomas Bogendoerfer af818031f4 rtc: ds1685: use devm_platform_ioremap_resource helper
Simplify ioremapping of registers by using devm_platform_ioremap_resource.

Signed-off-by: Thomas Bogendoerfer <tbogendoerfer@suse.de>
Acked-by: Joshua Kinard <kumba@gentoo.org>
Link: https://lore.kernel.org/r/20191011150546.9186-2-tbogendoerfer@suse.de
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
2019-10-14 17:49:22 +02:00
Thomas Bogendoerfer 9e420d7f12 rts: ds1685: remove not needed fields from private struct
A few of the fields in struct ds1685_priv aren't needed at all,
so we can remove it.

Signed-off-by: Thomas Bogendoerfer <tbogendoerfer@suse.de>
Acked-by: Joshua Kinard <kumba@gentoo.org>
Link: https://lore.kernel.org/r/20191011150546.9186-1-tbogendoerfer@suse.de
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
2019-10-14 17:49:21 +02:00
Thomas Gleixner d2912cb15b treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500
Based on 2 normalized pattern(s):

  this program is free software you can redistribute it and or modify
  it under the terms of the gnu general public license version 2 as
  published by the free software foundation

  this program is free software you can redistribute it and or modify
  it under the terms of the gnu general public license version 2 as
  published by the free software foundation #

extracted by the scancode license scanner the SPDX license identifier

  GPL-2.0-only

has been chosen to replace the boilerplate/reference in 4122 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Enrico Weigelt <info@metux.net>
Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Reviewed-by: Allison Randal <allison@lohutok.net>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190604081206.933168790@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-06-19 17:09:55 +02:00
Thomas Bogendoerfer 3b6bddda2f rtc: ds1685: use threaded interrupt
Handling of extended interrupts (kickstart, wake-up, ram-clear) was
moved off to a work queue, but the interrupts aren't acknowledged
in the interrupt handler. This leads to a deadlock, if driver
is used with interrupts. To fix this we use a threaded interrupt, get rid
of the work queue and do locking with just the rtc mutex lock.

Fixes: aaaf5fbf56 ("rtc: add driver for DS1685 family of real time clocks")
Signed-off-by: Thomas Bogendoerfer <tbogendoerfer@suse.de>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
2019-04-16 18:03:48 +02:00
Thomas Bogendoerfer e330c3d547 rtc: ds1685: remove dead code
ds1685_rtc_begin_ctrl_access/ds1685_rtc_end_ctrl_access aren't used,
so get rid of it.

Signed-off-by: Thomas Bogendoerfer <tbogendoerfer@suse.de>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
2019-04-16 18:03:46 +02:00
Thomas Bogendoerfer 692802d26b rtc: ds1685: fix crash caused by referencing wrong device struct
sysfs entries added by rtc_add_group are called with the rtc device
as argument and not the underlying device. Fixed by using the dev->parent

Fixes: cfb74916e2 ("rtc: ds1685: use rtc_add_group")
Signed-off-by: Thomas Bogendoerfer <tbogendoerfer@suse.de>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
2019-04-12 12:23:20 +02:00
Wolfram Sang 6f5b390b3a rtc: ds1685: simplify getting .driver_data
We should get 'driver_data' from 'struct device' directly. Going via
platform_device is an unneeded step back and forth.

Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
2018-10-22 17:53:12 +02:00
Alexandre Belloni cfb74916e2 rtc: ds1685: use rtc_add_group
Use rtc_add_group to add the sysfs group in a race free manner.

Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
2018-09-28 14:21:01 +02:00
Alexandre Belloni 482419e120 rtc: ds1685: use generic nvmem
Instead of adding a binary sysfs attribute from the driver, use the core to
register an nvmem device.

Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
2018-09-28 14:21:01 +02:00
Alexandre Belloni 8ddeb09de1 rtc: ds1685: drop RTC_DS1685_PROC_REGS
/proc is not the correct ABI to display debugging info. Remove
RTC_DS1685_PROC_REGS as the driver hasn't seen any real development since
it was included.

Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
2018-09-28 14:21:00 +02:00
Alexandre Belloni a41efe03e6 rtc: ds1685: remove sysfs access to control registers
Access to the control registers is mostly not needed and can cause runtime
issues (like missed interrupts). Remove this debugging interface.

Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
2018-06-20 12:38:14 +02:00
Alexandre Belloni 30a5271d45 rtc: ds1685: remove improper datetime access ABI
The driver exposes an undocumented ABI to access the date and time
registers. It is not actually used by any userspace tools. Remove it.

Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
2018-06-20 12:36:04 +02:00
Alexandre Belloni c36b52ed18 rtc: ds1685: Add range
Useful range is 2000-2099 because leap year fails on centuries.

Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
2018-05-31 23:02:11 +02:00
Alexandre Belloni a2ae8323a8 rtc: ds1685: fix possible race condition
The IRQ is requested before the struct rtc is allocated and registered, but
this struct is used in the IRQ handler.

Switch to devm_rtc_allocate_device/rtc_register_device to allocate the rtc
before requesting the IRQ.

Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
2018-05-31 23:02:11 +02:00
Wolfram Sang 85368bb9de rtc: simplify getting .drvdata
We should get drvdata from struct device directly. Going via
platform_device is an unneeded step back and forth.

Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Acked-by: Michal Simek <michal.simek@xilinx.com> (for zynqmp)
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
2018-05-03 22:08:00 +02:00
Alexandre Belloni 22652ba724 rtc: stop validating rtc_time in .read_time
The RTC core is always calling rtc_valid_tm after the read_time callback.
It is not necessary to call it just before returning from the callback.

Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
2018-03-02 10:09:58 +01:00
Uwe Kleine-König 56d86a7e79 rtc: simplify implementations of read_alarm
Since commit d68778b80d ("rtc: initialize output parameter for read
alarm to "uninitialized"") there is no need to explicitly set
unsupported members to -1. So drop the respective assignments from
drivers.

Signed-off-by: Uwe Kleine-König <uwe@kleine-koenig.org>
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
2016-07-09 10:24:45 +02:00
Heinrich Schuchardt c5776dec8f rtc: ds1685: correct day of month checking
The day of month is checked in ds1685_rtc_read_alarm
and ds1685_rtc_set_alarm.

Multiple errors exist in the day of month check.

Operator ! has a higher priority than &&.
(!(mday >= 1) && (mday <= 31)) is false for mday == 32.

When verifying the day of month the binary and the BCD mode
have to be considered.

Signed-off-by: Heinrich Schuchardt <xypron.glpk@gmx.de>
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
2016-06-04 15:46:08 +02:00
Josh Poimboeuf 19105f424b rtc: ds1685: actually spin forever in poweroff path
objtool reports the following warning:

  drivers/rtc/rtc-ds1685.o: warning: objtool: ds1685_rtc_poweroff() falls through to next function ds1685_rtc_work_queue()

Similar to commit 361c6ed6b1 ("rtc: ds1685: actually spin forever in
poweroff error path"), there's another unreachable() annotation which is
actually reachable, which we missed the first time.

Actually spin forever to be consistent with the comment and to make the
unreachable() annotation guaranteed to be unreachable.

Reported-by: kbuild test robot <fengguang.wu@intel.com>
Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
2016-05-20 12:33:51 +02:00
Alexandre Belloni fa5691131a rtc: remove useless DRV_VERSION
Many drivers are defining a DRV_VERSION. This is often only used for
MODULE_VERSION and sometimes to print an info message at probe time. This
is kind of pointless as they are all versionned with the kernel anyway.
Also the core will print a message when a new rtc is found.

Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
2016-05-20 12:33:51 +02:00
Josh Poimboeuf 361c6ed6b1 rtc: ds1685: actually spin forever in poweroff error path
objtool reports the following warnings:

  drivers/rtc/rtc-ds1685.o: warning: objtool: ds1685_rtc_work_queue()+0x0: duplicate frame pointer save
  drivers/rtc/rtc-ds1685.o: warning: objtool: ds1685_rtc_work_queue()+0x3: duplicate frame pointer setup
  drivers/rtc/rtc-ds1685.o: warning: objtool: ds1685_rtc_work_queue()+0x0: frame pointer state mismatch

The warning message needs to be improved, but what it really means in
this case is that ds1685_rtc_poweroff() has a possible code path where
it can actually fall through to the next function in the object code,
ds1685_rtc_work_queue().

The bug is caused by the use of the unreachable() macro in a place which
is actually reachable.  That causes gcc to assume that the printk()
immediately before the unreachable() macro never returns, when in fact
it does.  So gcc places the printk() at the very end of the function's
object code.  When the printk() returns, the next function starts
executing.

The surrounding comment and printk message state that the code should
spin forever, which explains the unreachable() statement.  However the
actual spin code is missing.

Reported-by: kbuild test robot <fengguang.wu@intel.com>
Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
2016-03-14 17:08:39 +01:00
Dan Carpenter 8c09b9fdec rtc: ds1685: passing bogus values to irq_restore
We call spin_lock_irqrestore with "flags" set to zero instead of to the
value from spin_lock_irqsave().

Fixes: aaaf5fbf56 ('rtc: add driver for DS1685 family of real time clocks')
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
2016-03-14 17:08:28 +01:00
Rasmus Villemoes 9c25a106c0 rtc: ds1685: don't try to micromanage sysfs output size
...and don't do it wrong.

"not ok or N/A" has length 13. Add the trailing newline, and the
snprintf return value will be 14. However, we lied to snprintf and
told it that only 13 bytes were available. Hence snprintf has only
written "not ok or N/" and a trailing '\0' to the buffer. Next we
continue lying, this time to the upper sysfs layer, claiming that we
wrote 14 meaningful bytes to the buffer. That'll make the upper layer
copy "not ok or N/" plus two nul bytes to user space (one nul byte
from snprintf, the other since sysfs takes care to clear the buffer
before giving it to the ->show method).

In the other cases, the claimed buffer size is closer to sufficient,
but we'll still get a nul byte instead of a newline written to user
space.  There's absolutely no reason to try to predict the output
size, and there's plenty of room in the buffer, so just use sprintf.

Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
2016-01-11 20:19:58 +01:00
Rasmus Villemoes ff67abd236 rtc: use %ph for short hex dumps
This makes the generated code slightly smaller.

Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
2016-01-11 20:19:58 +01:00
Vaishali Thakkar 508db592e2 rtc: ds1685: Use module_platform_driver
Use module_platform_driver for drivers whose init and exit functions
only register and unregister, respectively.

A simplified version of the Coccinelle semantic patch that performs
this transformation is as follows:

@a@
identifier f, x;
@@
-static f(...) { return platform_driver_register(&x); }

@b depends on a@
identifier e, a.x;
@@
-static e(...) { platform_driver_unregister(&x); }

@c depends on a && b@
identifier a.f;
declarer name module_init;
@@
-module_init(f);

@d depends on a && b && c@
identifier b.e, a.x;
declarer name module_exit;
declarer name module_platform_driver;
@@
-module_exit(e);
+module_platform_driver(x);

Signed-off-by: Vaishali Thakkar <vthakkar1994@gmail.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
2015-09-05 13:19:05 +02:00
Joe Perches a737e835e5 rtc: use more standard kernel logging styles
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 <joe@perches.com>
Acked-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
Cc: Alessandro Zummo <a.zummo@towertech.it>
Cc: Joshua Kinard <kumba@gentoo.org>
Cc: Chanwoo Choi <cw00.choi@samsung.com>
Reviewed-by: Krzysztof Kozlowski <k.kozlowski@samsung.com>
Tested-by: Krzysztof Kozlowski <k.kozlowski@samsung.com>
Cc: Aaro Koskinen <aaro.koskinen@iki.fi>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-04-17 09:04:02 -04:00
Joshua Kinard 52ef84d566 drivers/rtc/rtc-ds1685.c: fix sparse warnings
Fix two minor sparse warnings:

  CHECK   drivers/rtc/rtc-ds1685.c
  drivers/rtc/rtc-ds1685.c:2178:1: warning: function 'ds1685_rtc_poweroff' with external linkage has definition
  drivers/rtc/rtc-ds1685.c:802:23: warning: Using plain integer as NULL pointer

Fixes: aaaf5fbf56 ("rtc: add driver for DS1685 family of real time clocks")
Signed-off-by: Joshua Kinard <kumba@gentoo.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-04-17 09:04:00 -04:00
Joshua Kinard 269812de8b drivers/rtc/rtc-ds1685.c: remove .owner assignment from platform_driver
The rtc driver core now sets the platform_driver 'owner' property, so
remove the assignment from the DS1685 driver.

Fixes: aaaf5fbf56f1: "rtc: add driver for DS1685 family of real time clocks"
Signed-off-by: Joshua Kinard <kumba@gentoo.org>
Reported-by: kbuild test robot <fengguang.wu@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-04-17 09:04:00 -04:00
Joshua Kinard b00eeaedec drivers/rtc/rtc-ds1685.c: fix conditional in ds1685_rtc_sysfs_time_regs_{show,store}
Fix a conditional statement checking for NULL in both
ds1685_rtc_sysfs_time_regs_show and ds1685_rtc_sysfs_time_regs_store
that was using a logical AND when it should be using a logical OR so
that we fail out of the function properly if the condition ever
evaluates to true.

Fixes: aaaf5fbf56 ("rtc: add driver for DS1685 family of real time clocks")
Signed-off-by: Joshua Kinard <kumba@gentoo.org>
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-02-28 09:57:51 -08:00
Geert Uytterhoeven 39ea34cc07 rtc: ds1685: remove superfluous checks for out-of-range u8 values
drivers/rtc/rtc-ds1685.c: In function `ds1685_rtc_read_alarm':
drivers/rtc/rtc-ds1685.c:402: warning: comparison is always true due to limited range of data type
drivers/rtc/rtc-ds1685.c:409: warning: comparison is always true due to limited range of data type
drivers/rtc/rtc-ds1685.c:416: warning: comparison is always true due to limited range of data type
drivers/rtc/rtc-ds1685.c: In function `ds1685_rtc_set_alarm':
drivers/rtc/rtc-ds1685.c:475: warning: comparison is always true due to limited range of data type
drivers/rtc/rtc-ds1685.c:478: warning: comparison is always true due to limited range of data type
drivers/rtc/rtc-ds1685.c:481: warning: comparison is always true due to limited range of data type

u8 cannot contain a value larger than 0xff, hence drop the checks.
Wrapping the checks in unlikely() indicated some sense of humor, though ;-)

Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Acked-by: Joshua Kinard <kumba@gentoo.org>
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>
2015-02-28 09:57:51 -08:00
Arnd Bergmann 682354d4e0 rtc: ds1685: fix ds1685_rtc_alarm_irq_enable build error
The newly added ds1685 driver causes a build error when enabled without
CONFIG_RTC_INTF_DEV:

  drivers/rtc/rtc-ds1685.c:919:22: error: 'ds1685_rtc_alarm_irq_enable' undeclared here (not in a function)
    .alarm_irq_enable = ds1685_rtc_alarm_irq_enable,

Apparently the driver was incorrectly changed to reflect the interface
change from 16380c153a ("RTC: Convert rtc drivers to use the
alarm_irq_enable method"), which removed the respective #ifdef from all
other rtc drivers.

This does the same change that was merged for the other drivers before and
removes the #ifdef, allowing the interrupts to be enabled through the
in-kernel rtc interface independent of the existence of /dev/rtc.

Fixes: aaaf5fbf56 ("rtc: add driver for DS1685 family of real time clocks")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Joshua Kinard <kumba@gentoo.org>
Cc: Ralf Baechle <ralf@linux-mips.org>
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>
2015-02-28 09:57:51 -08:00
Joshua Kinard aaaf5fbf56 rtc: add driver for DS1685 family of real time clocks
This adds a driver for the Dallas/Maxim DS1685-family of RTC chips.  It
supports the DS1685/DS1687, DS1688/DS1691, DS1689/DS1693, DS17285/DS17287,
DS17485/DS17487, and DS17885/DS17887 RTC chips.  These chips are commonly
found in SGI O2 and SGI Octane systems.  It was originally derived from a
driver patch submitted by Matthias Fuchs many years ago for use in
EPPC-405-UC modules, which also used these RTCs.  In addition to the
time-keeping functions, this RTC also handles the shutdown mechanism of
the O2 and Octane and acts as a partial NVRAM for the boot PROMS in these
systems.

Verified on both an SGI O2 and an SGI Octane.

Signed-off-by: Joshua Kinard <kumba@gentoo.org>
Cc: Ralf Baechle <ralf@linux-mips.org>
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>
2015-02-16 17:56:05 -08:00