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* rtc: class: make rtc_class constantRicardo B. Marliere2024-03-081-8/+13
| | | | | | | | | | | | | | Since commit 43a7206b0963 ("driver core: class: make class_register() take a const *"), the driver core allows for struct class to be in read-only memory, so move the rtc_class structure to be declared at build time placing it into read-only memory, instead of having to be dynamically allocated at boot time. Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Suggested-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Ricardo B. Marliere <ricardo@marliere.net> Link: https://lore.kernel.org/r/20240305-class_cleanup-abelloni-v1-1-944c026137c8@marliere.net Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
* rtc: class: Remove usage of the deprecated ida_simple_xx() APIChristophe JAILLET2024-01-081-1/+1
| | | | | | | | | | | ida_alloc() and ida_free() should be preferred to the deprecated ida_simple_get() and ida_simple_remove(). This is less verbose. Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr> Link: https://lore.kernel.org/r/4f2c049cb09d46fed336e22445c71988b4f340d6.1702962419.git.christophe.jaillet@wanadoo.fr Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
* driver core: class: remove module * from class_create()Greg Kroah-Hartman2023-03-171-1/+1
| | | | | | | | | | | | 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>
* rtc: class: Fix potential memleak in devm_rtc_allocate_device()Shang XiaoJing2022-11-151-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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: 24d23181e43d ("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>
* rtc: Directly use ida_alloc()/free()keliu2022-06-241-3/+3
| | | | | | | | | 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
* rtc: remove uie_unsupportedAlexandre Belloni2022-03-231-3/+0
| | | | | | | 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
* rtc: fix use-after-free on device removalVincent Whitchurch2022-02-151-0/+9
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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
* rtc: expose RTC_FEATURE_UPDATE_INTERRUPTAlexandre Belloni2021-10-181-0/+4
| | | | | | | | 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
* rtc: expose correction featureAlexandre Belloni2021-10-181-0/+3
| | | | | | | | | 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
* rtc: class: check return value when calling dev_set_name()Yang Yingliang2021-10-151-1/+3
| | | | | | | | | | | | | | | | | | | | | 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
* rtc: class: don't call cdev_device_del() when cdev_device_add() failedYang Yingliang2021-10-151-3/+6
| | | | | | | | | | | | | | | | | | | | | | | | 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
* rtc: class: remove bogus documentationAlexandre Belloni2021-02-061-5/+0
| | | | | | | | rtc_device_unregister is gone since commit fdcfd854333b ("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
* rtc: introduce features bitfieldAlexandre Belloni2021-01-161-0/+5
| | | | | | | | | | | | | | 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
* Merge tag 'rtc-5.11' of ↵Linus Torvalds2020-12-201-33/+19
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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() ...
| * rtc: fix RTC removalAlexandre Belloni2020-12-161-1/+0
| | | | | | | | | | | | | | | | | | | | | | 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: fdcfd854333b ("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
| * rtc: destroy mutex when releasing the deviceBartosz Golaszewski2020-11-191-0/+1
| | | | | | | | | | | | | | | | | | 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
| * rtc: shrink devm_rtc_allocate_device()Bartosz Golaszewski2020-11-191-20/+9
| | | | | | | | | | | | | | | | | | | | | | 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
| * rtc: rework rtc_register_device() resource managementBartosz Golaszewski2020-11-191-10/+9
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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
| * rtc: nvmem: remove nvram ABIAlexandre Belloni2020-11-191-2/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | 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
* | ntp: Make the RTC sync offset less obscureThomas Gleixner2020-12-111-2/+7
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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
* | rtc: core: Make the sync offset default more realisticThomas Gleixner2020-12-111-1/+1
|/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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
* rtc: class: remove redundant assignment to variable errColin Ian King2020-04-021-1/+1
| | | | | | | | | | | 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>
* rtc: class: avoid unnecessary lookup in hctosysAlexandre Belloni2020-03-241-14/+2
| | | | | | | | 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>
* rtc: class: support hctosys from modular RTC driversSteve Muckle2020-03-231-0/+61
| | | | | | | | | | | | | 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>
* rtc: class: add debug message when registration failsAlexandre Belloni2019-08-201-1/+3
| | | | | | | | | | 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>
* rtc: core: correct trivial checkpatch warningsAlexandre Belloni2019-04-041-8/+6
| | | | | | | Correct trivial checkpatch warnings, mostly whitespace issues and unbalanced braces. Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
* rtc: convert core to SPDX identifierAlexandre Belloni2019-03-181-5/+2
| | | | | | | 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>
* rtc: class: reimplement devm_rtc_device_registerAlexandre Belloni2018-12-181-121/+36
| | | | | | | | | | | | 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>
* rtc: enforce rtc_timer_init private_data typeAlexandre Belloni2018-12-181-2/+2
| | | | | | | | 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>
* rtc: class: remove devm_rtc_device_unregisterAlexandre Belloni2018-11-121-26/+0
| | | | | | | 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>
* rtc: unexport non devm managed registrationAlexandre Belloni2018-09-131-7/+5
| | | | | | | 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>
* rtc: remove irq_task and irq_task_lockAlexandre Belloni2018-07-261-1/+0
| | | | | | | There is no way to set a periodic task anymore, remove task pointer and lock. Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
* rtc: use ktime_get_real_ts64() instead of getnstimeofday64()Arnd Bergmann2018-07-131-2/+2
| | | | | | | | | | | | | 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>
* rtc: Add one offset seconds to expand RTC rangeBaolin Wang2018-03-171-0/+70
| | | | | | | | | | | | | | | | | | | | | | 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>
* rtc: remove nvmem_configAlexandre Belloni2018-03-011-2/+0
| | | | | | | | | | 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>
* rtc: nvmem: allow registering the nvmem device before the rtcAlexandre Belloni2018-03-011-2/+3
| | | | | | | | | | | | | | | | | | | | | | | 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>
* rtc: nvmem: pass nvmem_config to rtc_nvmem_register()Alexandre Belloni2018-02-141-1/+1
| | | | | | | 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>
* rtc: Allow rtc drivers to specify the tv_nsec value for ntpJason Gunthorpe2017-10-301-0/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* rtc: add generic nvmem supportAlexandre Belloni2017-07-071-0/+4
| | | | | | | | | | | | 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>
* rtc: introduce new registration methodAlexandre Belloni2017-07-071-0/+84
| | | | | | | | | | 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>
* rtc: class separate id allocation from registrationAlexandre Belloni2017-07-071-19/+25
| | | | | | Create rtc_device_get_id to allocate the id for an RTC. Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
* rtc: class separate device allocation from registrationAlexandre Belloni2017-07-071-26/+37
| | | | | | | 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>
* rtc: remove rtc_device.nameAlexandre Belloni2017-06-031-4/+3
| | | | | | | 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>
* rtc: utilize new cdev_device_add helper functionLogan Gunthorpe2017-03-211-4/+10
| | | | | | | | | | | | | | | | | | | 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>
* rtc: make class.c explicitly non-modularPaul Gortmaker2016-03-141-13/+0
| | | | | | | | | | | | | | | | | | | | | | | | 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>
* rtc: switch to using is_visible() to control sysfs attributesDmitry Torokhov2015-09-051-3/+1
| | | | | | | | | | | | 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>
* rtc: class: remove unnecessary device_get() in rtc_device_unregisterDmitry Torokhov2015-09-051-13/+12
| | | | | | | | | | | 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>
* rtc: class: fix double free in rtc_register_device() error pathDmitry Torokhov2015-09-051-4/+2
| | | | | | | | | | | | Commit 59cca865f21e ("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>
* drivers/rtc/class.c: initialize rtc name earlyAaro Koskinen2015-04-171-3/+3
| | | | | | | | | | | | | | | | | 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>
* time, drivers/rtc: Don't bother with rtc_resume() for the nonstop clocksourceXunlei Pang2015-04-031-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | 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>
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