Commit Graph

91 Commits

Author SHA1 Message Date
Greg Kroah-Hartman 1aaba11da9 driver core: class: remove module * from class_create()
The module pointer in class_create() never actually did anything, and it
shouldn't have been requred to be set as a parameter even if it did
something.  So just remove it and fix up all callers of the function in
the kernel tree at the same time.

Cc: "Rafael J. Wysocki" <rafael@kernel.org>
Acked-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>
Link: https://lore.kernel.org/r/20230313181843.1207845-4-gregkh@linuxfoundation.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-03-17 15:16:33 +01:00
Shang XiaoJing 60da738082 rtc: class: Fix potential memleak in devm_rtc_allocate_device()
devm_rtc_allocate_device() will alloc a rtc_device first, and then run
dev_set_name(). If dev_set_name() failed, the rtc_device will memleak.
Move devm_add_action_or_reset() in front of dev_set_name() to prevent
memleak.

unreferenced object 0xffff888110a53000 (size 2048):
  comm "python3", pid 470, jiffies 4296078308 (age 58.882s)
  hex dump (first 32 bytes):
    00 00 00 00 00 00 00 00 08 30 a5 10 81 88 ff ff  .........0......
    08 30 a5 10 81 88 ff ff 00 00 00 00 00 00 00 00  .0..............
  backtrace:
    [<000000004aac0364>] kmalloc_trace+0x21/0x110
    [<000000000ff02202>] devm_rtc_allocate_device+0xd4/0x400
    [<000000001bdf5639>] devm_rtc_device_register+0x1a/0x80
    [<00000000351bf81c>] rx4581_probe+0xdd/0x110 [rtc_rx4581]
    [<00000000f0eba0ae>] spi_probe+0xde/0x130
    [<00000000bff89ee8>] really_probe+0x175/0x3f0
    [<00000000128e8d84>] __driver_probe_device+0xe6/0x170
    [<00000000ee5bf913>] device_driver_attach+0x32/0x80
    [<00000000f3f28f92>] bind_store+0x10b/0x1a0
    [<000000009ff812d8>] drv_attr_store+0x49/0x70
    [<000000008139c323>] sysfs_kf_write+0x8d/0xb0
    [<00000000b6146e01>] kernfs_fop_write_iter+0x214/0x2d0
    [<00000000ecbe3895>] vfs_write+0x61a/0x7d0
    [<00000000aa2196ea>] ksys_write+0xc8/0x190
    [<0000000046a600f5>] do_syscall_64+0x37/0x90
    [<00000000541a336f>] entry_SYSCALL_64_after_hwframe+0x63/0xcd

Fixes: 24d23181e4 ("rtc: class: check return value when calling dev_set_name()")
Signed-off-by: Shang XiaoJing <shangxiaojing@huawei.com>
Reviewed-by: Yang Yingliang <yangyingliang@huawei.com>
Link: https://lore.kernel.org/r/20221110090810.11225-1-shangxiaojing@huawei.com
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
2022-11-15 21:01:51 +01:00
keliu 592ff0c8d0 rtc: Directly use ida_alloc()/free()
Use ida_alloc()/ida_free() instead of deprecated
ida_simple_get()/ida_simple_remove() .

Signed-off-by: keliu <liuke94@huawei.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Link: https://lore.kernel.org/r/20220527073636.2474546-1-liuke94@huawei.com
2022-06-24 21:44:53 +02:00
Alexandre Belloni 1a31d63632 rtc: remove uie_unsupported
uie_unsupported is not used by any drivers anymore, remove it.

Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Link: https://lore.kernel.org/r/20220309162301.61679-29-alexandre.belloni@bootlin.com
2022-03-23 19:58:41 +01:00
Vincent Whitchurch c8fa17d9f0 rtc: fix use-after-free on device removal
If the irqwork is still scheduled or running while the RTC device is
removed, a use-after-free occurs in rtc_timer_do_work().  Cleanup the
timerqueue and ensure the work is stopped to fix this.

 BUG: KASAN: use-after-free in mutex_lock+0x94/0x110
 Write of size 8 at addr ffffff801d846338 by task kworker/3:1/41

 Workqueue: events rtc_timer_do_work
 Call trace:
  mutex_lock+0x94/0x110
  rtc_timer_do_work+0xec/0x630
  process_one_work+0x5fc/0x1344
  ...

 Allocated by task 551:
  kmem_cache_alloc_trace+0x384/0x6e0
  devm_rtc_allocate_device+0xf0/0x574
  devm_rtc_device_register+0x2c/0x12c
  ...

 Freed by task 572:
  kfree+0x114/0x4d0
  rtc_device_release+0x64/0x80
  device_release+0x8c/0x1f4
  kobject_put+0x1c4/0x4b0
  put_device+0x20/0x30
  devm_rtc_release_device+0x1c/0x30
  devm_action_release+0x54/0x90
  release_nodes+0x124/0x310
  devres_release_group+0x170/0x240
  i2c_device_remove+0xd8/0x314
  ...

 Last potentially related work creation:
  insert_work+0x5c/0x330
  queue_work_on+0xcc/0x154
  rtc_set_time+0x188/0x5bc
  rtc_dev_ioctl+0x2ac/0xbd0
  ...

Signed-off-by: Vincent Whitchurch <vincent.whitchurch@axis.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Link: https://lore.kernel.org/r/20211210160951.7718-1-vincent.whitchurch@axis.com
2022-02-15 23:06:19 +01:00
Alexandre Belloni adb17a053e rtc: expose RTC_FEATURE_UPDATE_INTERRUPT
Set RTC_FEATURE_UPDATE_INTERRUPT by default and clear it when it is not
supported.

Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Link: https://lore.kernel.org/r/20211018152337.78732-1-alexandre.belloni@bootlin.com
2021-10-18 17:25:52 +02:00
Alexandre Belloni 2268551935 rtc: expose correction feature
Add a new feature for RTCs able to correct the oscillator imprecision. This
is also called offset or trimming. Such drivers have a .set_offset callback,
use that to set the feature bit from the core.

Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Link: https://lore.kernel.org/r/20211018151933.76865-4-alexandre.belloni@bootlin.com
2021-10-18 17:20:50 +02:00
Yang Yingliang 24d23181e4 rtc: class: check return value when calling dev_set_name()
I got a null-ptr-deref report when doing fault injection test:

BUG: kernel NULL pointer dereference, address: 0000000000000000
RIP: 0010:strcmp+0xc/0x20
Call Trace:
 __devm_rtc_register_device.cold.7+0x16a/0x2df
 rv3029_probe+0x4b1/0x770 [rtc_rv3029c2]
 rv3029_i2c_probe+0x141/0x180 [rtc_rv3029c2]
 i2c_device_probe+0xa07/0xbb0
 really_probe+0x285/0xc30

If dev_set_name() fails, dev_name() is null, it causes null-ptr-deref,
we need check the return value of dev_set_name().

Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: Yang Yingliang <yangyingliang@huawei.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Link: https://lore.kernel.org/r/20211012041629.2504158-1-yangyingliang@huawei.com
2021-10-15 21:06:10 +02:00
Yang Yingliang 789c1093f0 rtc: class: don't call cdev_device_del() when cdev_device_add() failed
I got a null-ptr-deref report when doing fault injection test:

general protection fault, probably for non-canonical address 0xdffffc0000000022: 0000 [#1] SMP KASAN PTI
KASAN: null-ptr-deref in range [0x0000000000000110-0x0000000000000117]
RIP: 0010:device_del+0x132/0xdc0
Call Trace:
 cdev_device_del+0x1a/0x80
 devm_rtc_unregister_device+0x37/0x80
 release_nodes+0xc3/0x3b0

If cdev_device_add() fails, 'dev->p' is not set, it causes
null-ptr-deref when calling cdev_device_del(). Registering
character device is optional, we don't return error code
here, so introduce a new flag 'RTC_NO_CDEV' to indicate
if it has character device, cdev_device_del() is called
when this bit is not set.

Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: Yang Yingliang <yangyingliang@huawei.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Link: https://lore.kernel.org/r/20211011132114.3663509-1-yangyingliang@huawei.com
2021-10-15 21:05:33 +02:00
Alexandre Belloni d5328499bf rtc: class: remove bogus documentation
rtc_device_unregister is gone since commit fdcfd85433 ("rtc: rework
rtc_register_device() resource management"). Remove its documentation.

Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Link: https://lore.kernel.org/r/20210202112219.3610853-2-alexandre.belloni@bootlin.com
2021-02-06 00:58:24 +01:00
Alexandre Belloni 7ae41220ef rtc: introduce features bitfield
Introduce a bitfield to allow the drivers to announce the available
features for an RTC.

The main use case would be to better handle alarms, that could be present
or not or have a minute resolution or may need a correct week day to be set.

Use the newly introduced RTC_FEATURE_ALARM bit to then test whether alarms
are available instead of relying on the presence of ops->set_alarm.

Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Link: https://lore.kernel.org/r/20210110231752.1418816-2-alexandre.belloni@bootlin.com
2021-01-16 23:19:26 +01:00
Linus Torvalds f4a2f7866f RTC for 5.11
Subsystem:
  - Remove nvram ABI. There was no complaints about the deprecation for the last
    3 years.
  - Improve RTC device allocation and registration
  - Now available for ARCH=um
 
 Drivers:
  - at91rm9200: correction and sam9x60 support
  - ds1307: improve ACPI support
  - mxc: now DT only
  - pcf2127: watchdog support now needs the reset-source property
  - pcf8523: set range
  - rx6110: i2c support
 -----BEGIN PGP SIGNATURE-----
 
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 NOU06g//Xf2697Zc59SziSwhbEFCEyfhY4P+Qm24ymuOb2wkApmaWGifdCRclcvR
 VncDLhyW9u5SpJiQY0ZMryTOmuE2KtbGfJX/tY9AGgQZioCxUIxELREwnqkQ2/8c
 cOu0C8nrBCAnDNi3jTryPCyFJN1oLCztcbMGWXGG7Irkehq7ywQ1TCxxWzF+w3su
 z38UzB1664ULfYYj3M2m/+2MV2rkf81P/4BTokKkZ2RLL1Q19wM0rFE0aXcKedel
 pZy/DXGwBWK4fDR/Q2YYxRnpEf8UzYzgCQWAiaJGdRane9Tx6H8wy9TcHc5OQfjn
 gtDtXje9Xwb+UJ27Mz19hNMts96n2G9S1Y0Pq5n0DD4AO0pDchYL41V5Z4hEDgMW
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 UZ1SNxLZy2O7QL5Y+00pHlVFizTyGITz1H2IBG1Fn62abh7H9G5wfsB4AEldR+tr
 9Di/o7Q1Oo5goBtVdmqn3xfOr1QWlfU+/7qSwiz2uqXMR/UWVMlLSp7k2Hav1m5H
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 R5JP6lgCoZJPky0156qApAH8I6r6xV1A7W7CEnNKOK1JITqj5Hw=
 =n8V2
 -----END PGP SIGNATURE-----

Merge tag 'rtc-5.11' of git://git.kernel.org/pub/scm/linux/kernel/git/abelloni/linux

Pull RTC updates from Alexandre Belloni:
 "Subsystem:

   - Remove nvram ABI. There was no complaints about the deprecation for
     the last 3 years.

   - Improve RTC device allocation and registration

   - Now available for ARCH=um

  Drivers:

   - at91rm9200: correction and sam9x60 support

   - ds1307: improve ACPI support

   - mxc: now DT only

   - pcf2127: watchdog support now needs the reset-source property

   - pcf8523: set range

   - rx6110: i2c support"

* tag 'rtc-5.11' of git://git.kernel.org/pub/scm/linux/kernel/git/abelloni/linux: (43 commits)
  rtc: pcf2127: only use watchdog when explicitly available
  dt-bindings: rtc: add reset-source property
  rtc: fix RTC removal
  rtc: s3c: Remove dead code related to periodic tick handling
  rtc: s3c: Disable all enable (RTC, tick) bits in the probe
  rtc: ep93xx: Fix NULL pointer dereference in ep93xx_rtc_read_time
  rtc: test: remove debug message
  rtc: mxc{,_v2}: enable COMPILE_TEST
  rtc: enable RTC framework on ARCH=um
  rtc: pcf8523: use BIT
  rtc: pcf8523: set range
  rtc: pcf8523: switch to devm_rtc_allocate_device
  rtc: destroy mutex when releasing the device
  rtc: shrink devm_rtc_allocate_device()
  rtc: rework rtc_register_device() resource management
  rtc: nvmem: emit an error message when nvmem registration fails
  rtc: add devm_ prefix to rtc_nvmem_register()
  rtc: nvmem: remove nvram ABI
  Documentation: list RTC devres helpers in devres.rst
  rtc: omap: use devm_pinctrl_register()
  ...
2020-12-20 10:12:06 -08:00
Alexandre Belloni f70cc33029 rtc: fix RTC removal
Since the rtc_register_device, removing an RTC device will end with a
refcount_t: underflow; use-after-free warning since put_device is called
twice in the device tear down path.

Fixes: fdcfd85433 ("rtc: rework rtc_register_device() resource management")
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Reviewed-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
Link: https://lore.kernel.org/r/20201205231449.610980-1-alexandre.belloni@bootlin.com
2020-12-16 00:33:33 +01:00
Thomas Gleixner 69eca258c8 ntp: Make the RTC sync offset less obscure
The current RTC set_offset_nsec value is not really intuitive to
understand. 

  tsched       twrite(t2.tv_sec - 1) 	 t2 (seconds increment)

The offset is calculated from twrite based on the assumption that t2 -
twrite == 1s. That means for the MC146818 RTC the offset needs to be
negative so that the write happens 500ms before t2.

It's easier to understand when the whole calculation is based on t2. That
avoids negative offsets and the meaning is obvious:

 t2 - twrite:     The time defined by the chip when seconds increment
      		  after the write.

 twrite - tsched: The time for the transport to the point where the chip
 	  	  is updated. 

==> set_offset_nsec =  t2 - tsched
    ttransport      =  twrite - tsched
    tRTCinc         =  t2 - twrite
==> set_offset_nsec =  ttransport + tRTCinc

tRTCinc is a chip property and can be obtained from the data sheet.

ttransport depends on how the RTC is connected. It is close to 0 for
directly accessible RTCs. For RTCs behind a slow bus, e.g. i2c, it's the
time required to send the update over the bus. This can be estimated or
even calibrated, but that's a different problem.

Adjust the implementation and update comments accordingly.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Link: https://lore.kernel.org/r/20201206220542.263204937@linutronix.de
2020-12-11 10:40:53 +01:00
Thomas Gleixner 354c796b92 rtc: core: Make the sync offset default more realistic
The offset which is used to steer the start of an RTC synchronization
update via rtc_set_ntp_time() is huge. The math behind this is:

  tsched       twrite(t2.tv_sec - 1) 	 t2 (seconds increment)

twrite - tsched is the transport time for the write to hit the device.

t2 - twrite depends on the chip and is for most chips one second.

The rtc_set_ntp_time() calculation of tsched is:

    tsched = t2 - 1sec - (t2 - twrite)

The default for the sync offset is 500ms which means that twrite - tsched
is 500ms assumed that t2 - twrite is one second.

This is 0.5 seconds off for RTCs which are directly accessible by IO writes
and probably for the majority of i2C/SPI based RTC off by an order of
magnitude. Set it to 5ms which should bring it closer to reality.

The default can be adjusted by drivers (rtc_cmos does so) and could be
adjusted further by a calibration method which is an orthogonal problem.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Acked-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Link: https://lore.kernel.org/r/20201206220541.960333166@linutronix.de
2020-12-11 10:40:52 +01:00
Bartosz Golaszewski 0d6d7a390b rtc: destroy mutex when releasing the device
Not destroying mutexes doesn't lead to resource leak but it's the correct
thing to do for mutex debugging accounting.

Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Link: https://lore.kernel.org/r/20201110094205.8972-1-brgl@bgdev.pl
2020-11-19 12:50:12 +01:00
Bartosz Golaszewski 1bfc485b73 rtc: shrink devm_rtc_allocate_device()
We don't need to use devres_alloc() & devres_add() manually if all we
want to manage is a single pointer. We can shrink the code by using
devm_add_action_or_reset() instead. The number of allocations stays
the same.

Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Link: https://lore.kernel.org/r/20201109163409.24301-9-brgl@bgdev.pl
2020-11-19 12:50:12 +01:00
Bartosz Golaszewski fdcfd85433 rtc: rework rtc_register_device() resource management
rtc_register_device() is a managed interface but it doesn't use devres
by itself - instead it marks an rtc_device as "registered" and the devres
callback for devm_rtc_allocate_device() takes care of resource release.

This doesn't correspond with the design behind devres where managed
structures should not be aware of being managed. The correct solution
here is to register a separate devres callback for unregistering the
device.

While at it: rename rtc_register_device() to devm_rtc_register_device()
and add it to the list of managed interfaces in devres.rst. This way we
can avoid any potential confusion of driver developers who may expect
there to exist a corresponding unregister function.

Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Link: https://lore.kernel.org/r/20201109163409.24301-8-brgl@bgdev.pl
2020-11-19 12:50:12 +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
Colin Ian King 3edf29d9d5 rtc: class: remove redundant assignment to variable err
The variable err is being initialized with a value that is never read
and it is being updated later with a new value. The initialization
is redundant and can be removed.

Addresses-Coverity: ("Unused value")
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Link: https://lore.kernel.org/r/20200402110411.508534-1-colin.king@canonical.com
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
2020-04-02 18:47:30 +02:00
Alexandre Belloni 5614a4a3ca rtc: class: avoid unnecessary lookup in hctosys
rtc_hctosys is only called when the relevant RTC is found, avoid looking it
up while we already have a pinter to the proper struct rtc_device.

Link: https://lore.kernel.org/r/20200323213039.297458-1-alexandre.belloni@bootlin.com
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
2020-03-24 22:48:04 +01:00
Steve Muckle f9b2a4d6a5 rtc: class: support hctosys from modular RTC drivers
Due to distribution constraints it may not be possible to statically
compile the required RTC driver into the kernel.

Expand RTC_HCTOSYS support to cover all RTC devices (statically compiled
or not) by checking at the end of RTC device registration whether the
time should be synced.

Signed-off-by: Steve Muckle <smuckle@google.com>
Link: https://lore.kernel.org/r/20191106194625.116692-1-smuckle@google.com
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
2020-03-23 21:14:34 +01:00
Alexandre Belloni 924068e50a rtc: class: add debug message when registration fails
Add a message when __rtc_register_device fails because rtc->ops is NULL.
This may only happen when developing a new driver so use dev_dbg to avoid
compiling it in by default.

Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Link: https://lore.kernel.org/r/20190818220041.17833-1-alexandre.belloni@bootlin.com
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
2019-08-20 21:44:45 +02:00
Alexandre Belloni 606cc43c72 rtc: core: correct trivial checkpatch warnings
Correct trivial checkpatch warnings, mostly whitespace issues and
unbalanced braces.

Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
2019-04-04 10:07:08 +02:00
Alexandre Belloni cdf7545aef rtc: convert core to SPDX identifier
Use SPDX-License-Identifier instead of a verbose license text. Also fix the
block comment alignment.

Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
2019-03-18 03:36:01 +01:00
Alexandre Belloni a269441493 rtc: class: reimplement devm_rtc_device_register
Implement devm_rtc_device_register using devm_rtc_allocate_device and
__rtc_register_device so there is only one path left to register rtc
devices.

Also mark it as deprecated so new drivers will hopefully use
devm_rtc_allocate_device and rtc_register_device that are less race prone
and allow avoiding the 2038, 2070, 2100 and 2106 bugs properly.

Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
2018-12-18 22:53:32 +01:00
Alexandre Belloni 9a03201170 rtc: enforce rtc_timer_init private_data type
All the remaining users of rtc_timers are passing the rtc_device as private
data. Enforce that and rename private_data to rtc.

Suggested-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
2018-12-18 22:53:29 +01:00
Alexandre Belloni 03f39f47dc rtc: class: remove devm_rtc_device_unregister
devm_rtc_device_unregister is not used by any driver and should not be used
by any new driver.

Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
2018-11-12 23:14:10 +01:00
Alexandre Belloni 1e479c619b rtc: unexport non devm managed registration
Ensure the non managed version of the un/registration functions is not used
anymore. No driver is using it anymore and they should not be necessary.

Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
2018-09-13 15:43:05 +02:00
Alexandre Belloni acecb3ad8b rtc: remove irq_task and irq_task_lock
There is no way to set a periodic task anymore, remove task pointer and
lock.

Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
2018-07-26 15:08:53 +02:00
Arnd Bergmann 5089ea15ba rtc: use ktime_get_real_ts64() instead of getnstimeofday64()
getnstimeofday64() is just a wrapper around the ktime accessor, so
we should use that directly.

I considered using ktime_get_boottime_ts64() (to avoid leap second
problems) or ktime_get_real_seconds() (to simplify the calculation,
but in the end concluded that the existing interface is probably
the most appropriate in this case.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
2018-07-13 10:47:18 +02:00
Baolin Wang 989515647e rtc: Add one offset seconds to expand RTC range
From our investigation for all RTC drivers, 1 driver will be expired before
year 2017, 7 drivers will be expired before year 2038, 23 drivers will be
expired before year 2069, 72 drivers will be expired before 2100 and 104
drivers will be expired before 2106. Especially for these early expired
drivers, we need to expand the RTC range to make the RTC can still work
after the expired year.

So we can expand the RTC range by adding one offset to the time when reading
from hardware, and subtracting it when writing back. For example, if you have
an RTC that can do 100 years, and currently is configured to be based in
Jan 1 1970, so it can represents times from 1970 to 2069. Then if you change
the start year from 1970 to 2000, which means it can represents times from
2000 to 2099. By adding or subtracting the offset produced by moving the wrap
point, all times between 1970 and 1999 from RTC hardware could get interpreted
as times from 2070 to 2099, but the interpretation of dates between 2000 and
2069 would not change.

Signed-off-by: Baolin Wang <baolin.wang@linaro.org>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
2018-03-17 14:20:55 +01:00
Alexandre Belloni 0391df74a6 rtc: remove nvmem_config
Because nvmem_config is only used and copied at nvmem registration, remove
it from struct rtc_device.

All the rtc drivers using nvmem are now calling rtc_nvmem_register
directly.

Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
2018-03-01 10:49:23 +01:00
Alexandre Belloni ac75779b72 rtc: nvmem: allow registering the nvmem device before the rtc
Switch the parent of the nvmem device to the parent of the rtc device so it
can be registered before the RTC.

This is a small change in the ABI as the nvmem moves out of the
/sys/class/rtc/rtcX folder to be under the parent device folder (that is
where the previous nvram files where registered).

However, it is still available under its correct location,
/sys/bus/nvmem/devices which is the one that should be used by userspace
applications.

The other benefit is that the nvmem device can stay registered even if the
rtc registration fails. Or it is possible to not register the rtc if the
nvmem registration failed.

Finally, it makes a lot of sense for devices that actually have different
i2c or spi addresses for the RTC and the EEPROM. That is basically how it
would end up when using MFD or even completely separate devices.

Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
2018-03-01 10:49:14 +01:00
Alexandre Belloni 4cce9d3988 rtc: nvmem: pass nvmem_config to rtc_nvmem_register()
To be able to remove nvmem_config from struct rtc_device, pass it as a
parameter to rtc_nvmem_register.

Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
2018-02-14 20:58:11 +01:00
Jason Gunthorpe 0f295b0650 rtc: Allow rtc drivers to specify the tv_nsec value for ntp
ntp is currently hardwired to try and call the rtc set when wall clock
tv_nsec is 0.5 seconds. This historical behaviour works well with certain
PC RTCs, but is not universal to all rtc hardware.

Change how this works by introducing the driver specific concept of
set_offset_nsec, the delay between current wall clock time and the target
time to set (with a 0 tv_nsecs).

For x86-style CMOS set_offset_nsec should be -0.5 s which causes the last
second to be written 0.5 s after it has started.

For compat with the old rtc_set_ntp_time, the value is defaulted to
+ 0.5 s, which causes the next second to be written 0.5s before it starts,
as things were before this patch.

Testing shows many non-x86 RTCs would like set_offset_nsec ~= 0,
so ultimately each RTC driver should set the set_offset_nsec according
to its needs, and non x86 architectures should stop using
update_persistent_clock64 in order to access this feature.
Future patches will revise the drivers as needed.

Since CMOS and RTC now have very different handling they are split
into two dedicated code paths, sharing the support code, and ifdefs
are replaced with IS_ENABLED.

Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Miroslav Lichvar <mlichvar@redhat.com>
Cc: Richard Cochran <richardcochran@gmail.com>
Cc: Prarit Bhargava <prarit@redhat.com>
Cc: Stephen Boyd <stephen.boyd@linaro.org>
Signed-off-by: Jason Gunthorpe <jgunthorpe@obsidianresearch.com>
Signed-off-by: John Stultz <john.stultz@linaro.org>
2017-10-30 15:03:24 -07:00
Alexandre Belloni 697e5a47aa rtc: add generic nvmem support
Many RTCs have an on board non volatile storage. It can be battery backed
RAM or an EEPROM. Use the nvmem subsystem to export it to both userspace
and in-kernel consumers.

This stays compatible with the previous (non documented) ABI that was using
/sys/class/rtc/rtcx/device/nvram to export that memory. But will warn about
the deprecation.

Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
2017-07-07 13:14:14 +02:00
Alexandre Belloni 3068a254d5 rtc: introduce new registration method
Introduce rtc_register_device() to register an already allocated and
initialized struct rtc_device. It automatically sets up the owner and the
two steps allocation/registration will allow to remove race conditions in
the IRQ handling of some driver. It also allows to properly extend the core
without adding more arguments to rtc_device_register().

Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
2017-07-07 13:14:10 +02:00
Alexandre Belloni b91336df8a rtc: class separate id allocation from registration
Create rtc_device_get_id to allocate the id for an RTC.

Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
2017-07-07 13:14:08 +02:00
Alexandre Belloni d1bec20fac rtc: class separate device allocation from registration
Create rtc_allocate_device to allocate memory for a struct rtc_device and
initialize it.

Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
2017-07-07 13:14:06 +02:00
Alexandre Belloni 5c82a6ae02 rtc: remove rtc_device.name
rtc->name is only used in messages were it is superfluous. Remove it
completely from the structure.

Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
2017-06-03 10:55:36 +02:00
Logan Gunthorpe d5ed9177f6 rtc: utilize new cdev_device_add helper function
Mostly straightforward, but we had to remove the rtc_dev_add/del_device
functions as they split up the cdev_add and the device_add.

Doing this also revealed that there was likely another subtle bug:
seeing cdev_add was done after device_register, the cdev probably
was not ready before device_add when the uevent occurs. This would
race with userspace, if it tried to use the device directly after
the uevent. This is fixed just by using the new helper function.

Another weird thing is this driver would, in some error cases, call
cdev_add() without calling cdev_init. This patchset corrects this
by avoiding calling cdev_add if the devt is not set.

Signed-off-by: Logan Gunthorpe <logang@deltatee.com>
Acked-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-03-21 06:44:33 +01:00
Paul Gortmaker 270a3bd6bd rtc: make class.c explicitly non-modular
The Makefile/Kconfig currently controlling compilation of this code is:

obj-$(CONFIG_RTC_CLASS)         += rtc-core.o
rtc-core-y                      := class.o interface.o

drivers/rtc/Kconfig:menuconfig RTC_CLASS
drivers/rtc/Kconfig:    bool "Real Time Clock"

...meaning that it currently is not being built as a module by anyone.

Lets remove the modular code that is essentially orphaned, so that
when reading the code there is no doubt it is builtin-only.

We don't replace module.h with init.h since the file does need
to know what a struct module is.

We also delete the MODULE_LICENSE tag etc. since all that information
is already contained at the top of the file in the comments.

Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
2016-03-14 17:08:18 +01:00
Dmitry Torokhov 3ee2c40b7a rtc: switch to using is_visible() to control sysfs attributes
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 <dmitry.torokhov@gmail.com>
Reviewed-by: Krzysztof Kozlowski <k.kozlowski@samsung.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
2015-09-05 13:19:07 +02:00
Dmitry Torokhov c3b399a4b6 rtc: class: remove unnecessary device_get() in rtc_device_unregister
Technically the address of rtc->dev can never be NULL, so get_device()
can never fail. Also caller of rtc_device_unregister() supposed to be
the owner of the device and thus have a valid reference. Therefore
call to get_device() is not needed here.

Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Reviewed-by: Krzysztof Kozlowski <k.kozlowski@samsung.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
2015-09-05 13:19:07 +02:00
Dmitry Torokhov 6706664d92 rtc: class: fix double free in rtc_register_device() error path
Commit 59cca865f2 ("drivers/rtc/class.c: fix device_register() error
handling") correctly noted that naked kfree() should not be used after
failed device_register() call, however, while it added the needed
put_device() it forgot to remove the original kfree() causing double-free.

Cc: Vasiliy Kulikov <segooon@gmail.com>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Reviewed-by: Krzysztof Kozlowski <k.kozlowski@samsung.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
2015-09-05 13:19:07 +02:00
Aaro Koskinen 182683e955 drivers/rtc/class.c: initialize rtc name early
In some error cases RTC name is used before it is initialized:

	rtc-rs5c372 0-0032: clock needs to be set
	rtc-rs5c372 0-0032: rs5c372b found, 24hr, driver version 0.6
	rtc (null): read_time: fail to read
	rtc-rs5c372 0-0032: rtc core: registered rtc-rs5c372 as rtc0

Fix by initializing the name early.

Signed-off-by: Aaro Koskinen <aaro.koskinen@iki.fi>
Acked-by: Alexandre Belloni <alexandre.belloni@free-electrons.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>
2015-04-17 09:04:01 -04:00
Xunlei Pang 0fa88cb4b8 time, drivers/rtc: Don't bother with rtc_resume() for the nonstop clocksource
If a system does not provide a persistent_clock(), the time
will be updated on resume by rtc_resume(). With the addition
of the non-stop clocksources for suspend timing, those systems
set the time on resume in timekeeping_resume(), but may not
provide a valid persistent_clock().

This results in the rtc_resume() logic thinking no one has set
the time and it then will over-write the suspend time again,
which is not necessary and only increases clock error.

So, fix this for rtc_resume().

This patch also improves the name of persistent_clock_exist to
make it more grammatical.

Signed-off-by: Xunlei Pang <pang.xunlei@linaro.org>
Signed-off-by: John Stultz <john.stultz@linaro.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1427945681-29972-19-git-send-email-john.stultz@linaro.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-04-03 08:18:34 +02:00
Xunlei Pang 814dcf8ead drivers/rtc: Remove redundant rtc_valid_tm() from rtc_resume()
rtc_read_time() has already judged valid tm by rtc_valid_tm(),
so just remove it.

Signed-off-by: Xunlei Pang <pang.xunlei@linaro.org>
Signed-off-by: John Stultz <john.stultz@linaro.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1427945681-29972-17-git-send-email-john.stultz@linaro.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-04-03 08:18:32 +02:00
John Stultz d4bda8f843 rtc: Update suspend/resume timing to use 64bit time
Currently the rtc suspend/resume timing is done using
y2038 problematic timespecs. So update the code to utilize
timespec64 types.

Signed-off-by: John Stultz <john.stultz@linaro.org>
2014-11-21 12:00:00 -08:00