Commit Graph

36 Commits

Author SHA1 Message Date
Dominique Martinet 03a86cda41 rtc: rv8803: fix writing back ctrl in flag register
ctrl is set from read_regs(..FLAG, 2, ctrl), so ctrl[0] is FLAG
and ctrl[1] is the CTRL register.
Use ctrl[0] to write back to the FLAG register as appropriate.

Signed-off-by: Dominique Martinet <dominique.martinet@atmark-techno.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Link: https://lore.kernel.org/r/20211101013400.325855-1-dominique.martinet@atmark-techno.com
2021-11-10 00:44:08 +01:00
Alexandre Belloni da82632150 rtc: rv8803: quiet maybe-unused variable warning
When CONFIG_OF is disabled then the matching table is not referenced.

Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Link: https://lore.kernel.org/r/20210202112219.3610853-18-alexandre.belloni@bootlin.com
2021-02-06 00:58:25 +01:00
Alexandre Belloni 45909e5cda rtc: rv8803: constify rv8803_rtc_ops
Use RTC_FEATURE_ALARM to signal to the core whether alarms are available
instead of changing the global struct rtc_class_ops, allowing to make it
const.

Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Link: https://lore.kernel.org/r/20210110231752.1418816-17-alexandre.belloni@bootlin.com
2021-01-16 23:19:27 +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
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
Liu Shixin 179b4bcc4c rtc: rv8803: simplify the return expression of rv8803_nvram_write
Simplify the return expression.

Signed-off-by: Liu Shixin <liushixin2@huawei.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Link: https://lore.kernel.org/r/20200921082449.2591981-1-liushixin2@huawei.com
2020-09-29 22:20:10 +02:00
Alexandre Belloni bcd17c5082 rtc: rv8803: return meaningful value for RTC_VL_READ
RV8803_FLAG_V1F means the voltage is too low to keep the temperature
compensation running and the accuracy of the RTC is affected.

RV8803_FLAG_V2F means the voltage dropped so low that data is now invalid.

Link: https://lore.kernel.org/r/20191214220259.621996-16-alexandre.belloni@bootlin.com
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
2019-12-18 10:37:42 +01:00
Alexandre Belloni 7e890a0f0e rtc: rv8803: avoid clearing RV8803_FLAG_V2F in RTC_VL_CLR
Stop clearing RV8803_FLAG_V2F in RTC_VL_CLR because it is a disservice to
userspace as it removes the important information that the RTC data is
invalid. This may lead userspace to set an invalid system time later on.

Link: https://lore.kernel.org/r/20191214220259.621996-15-alexandre.belloni@bootlin.com
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
2019-12-18 10:37:40 +01:00
Alexandre Belloni 44c638ce4e rtc: remove superfluous error message
The RTC core now has error messages in case of registration failure, there
is no need to have other messages in the drivers.

Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Link: https://lore.kernel.org/r/20190818220041.17833-2-alexandre.belloni@bootlin.com
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
2019-08-21 09:57:23 +02:00
Wolfram Sang 5cb172694a rtc: rv8803: simplify getting the adapter of a client
We have a dedicated pointer for that, so use it. Much easier to read and
less computation involved.

Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
2019-06-09 16:48:06 +02:00
Alexandre Belloni 7d1e5bfe17 rtc: update my email address
Use my current email address.

Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
2019-03-04 20:21:19 +01:00
Alexandre Belloni 182ae2bb64 rtc: rv8803: convert to SPDX identifier
Use SPDX-License-Identifier instead of a verbose license text.

Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
2019-03-04 20:21:19 +01:00
Alexandre Belloni 2e17f8b982 rtc: rv8803: let the core handle range
Let the core handle the RTC range instead of open coding it.

Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
2019-03-04 20:21:19 +01:00
Alexandre Belloni ac771ed746 rtc: rv8803: add Epson RX8803 support
The Epson rx8803 is mostly similar to the Microcrystal RV8803 but the size
of the offset register is 4 bits vs 6 bits but it has a configurable
temperature compensation.

Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
2018-08-27 23:24:36 +02:00
Alexandre Belloni c856618d20 rtc: rv8803: fix the rv8803 id in the OF table
The ID for RV8803 must be rv_8803

Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
2018-08-27 23:24:35 +02:00
Alexandre Belloni ce1ae8eb83 rtc: rv8803: fix possible race condition
The probe function is not allowed to fail after registering the RTC. Call
rtc_register_device() at the end.

Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
2018-03-01 10:49:23 +01:00
Alexandre Belloni c07fd9dea2 rtc: rv8803: put struct nvmem_config on the stack
Avoid allocating memory for struct nvmem_config.

Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
2018-03-01 10:49:22 +01:00
Alexandre Belloni 88d3aadea0 rtc: rv8803: call rtc_nvmem_register()
Call rtc_nvmem_register instead of letting the core do it and stop using
the nvmem_config member of struct rtc_device.

Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
2018-03-01 10:49:22 +01:00
Alexandre Belloni 2a52482ffb rtc: rv8803: remove rv8803_remove
rv8803_remove() is now empty, remove it.

Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
2017-07-07 13:14:19 +02:00
Alexandre Belloni 16d70a78b4 rtc: rv8803: use generic nvmem support
Instead of adding a binary sysfs attribute from the driver (which suffers
from a race condition as the attribute appears after the device), use the
core to register an nvmem device.

Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
2017-07-07 13:14:18 +02:00
Alexandre Belloni 7133eca195 rtc: rv8803: switch to rtc_register_device
This removes a possible race condition and allows for further improvement
of the driver.

Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
2017-07-07 13:14:16 +02:00
Javier Martinez Canillas 740ad8f43c rtc: rv8803: Add OF device ID table
The driver doesn't have a struct of_device_id table but supported devices
are registered via Device Trees. This is working on the assumption that a
I2C device registered via OF will always match a legacy I2C device ID and
that the MODALIAS reported will always be of the form i2c:<device>.

But this could change in the future so the correct approach is to have an
OF device ID table if the devices are registered via OF.

Signed-off-by: Javier Martinez Canillas <javier@osg.samsung.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
2017-03-09 01:29:14 +01:00
Oleksij Rempel 1cd713762e rtc: rv8803: set VDETOFF and SWOFF via device tree
There might be designs where the power supply circuit is designed
in a way that VDETOFF and SWOFF is required to be set. Otherwise the
RTC detects a power loss. Add a device tree interface for this.

Signed-off-by: Carsten Resch <Carsten.Resch@de.bosch.com>
Signed-off-by: Dirk Behme <dirk.behme@de.bosch.com>
Signed-off-by: Oleksij Rempel <fixed-term.Oleksij.Rempel@de.bosch.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
2016-10-12 13:24:39 +02:00
Benoît Thébaudeau 6f367788d6 rtc: rv8803: Clear V1F when setting the time
V1F indicates that the time accuracy may have been compromised because
of a voltage drop (possibly only temporary) below VLOW1, which stops the
temperature compensation. When the time is set, the accuracy is
restored, so V1F should be cleared in order to indicate this and to be
able to detect the next temperature compensation loss. This is the same
principle as for V2F, which is cleared when the time is set to indicate
that the time is no longer invalid and to be able to detect the next
data loss.

Signed-off-by: Benoît Thébaudeau <benoit@wsystem.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
2016-07-28 09:59:43 +02:00
Benoît Thébaudeau d3700b6b64 rtc: rv8803: Stop the clock while setting the time
According to the application manual of the RX8900, the RESET bit must be
set to 1 to prevent a timer update while setting the time. This also
resets the subsecond counter. The application manual of the RV-8803 does
not mention such a requirement, and it says that the 100th Seconds
register is cleared when writing to the Seconds register, but using the
RESET bit for the RV-8803 too should not be an issue and is probably
safer.

This change also ensures that the RESET bit is initialized properly in
all cases. Indeed, all the registers must be initialized if the voltage
has been lower than VLOW2 (triggering V2F), but not low enough to
trigger a POR.

Signed-off-by: Benoît Thébaudeau <benoit@wsystem.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
2016-07-28 09:59:41 +02:00
Benoît Thébaudeau d522649e26 rtc: rv8803: Always apply the I²C workaround
The I²C NACK issue of the RV-8803 may occur after any I²C START
condition, depending on the timings. Consequently, the workaround must
be applied for all the I²C transfers.

This commit abstracts the I²C transfer code into register access
functions. This avoids duplicating the I²C workaround everywhere. This
also avoids the duplication of the code handling the return value of
i2c_smbus_read_i2c_block_data(). Error messages are issued in case of
definitive register access failures (if the workaround fails). This
change also makes the I²C transfer return value checks consistent.

Signed-off-by: Benoît Thébaudeau <benoit@wsystem.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
2016-07-28 09:59:39 +02:00
Benoît Thébaudeau a1e98e0970 rtc: rv8803: Fix read day of week
The Weekday register is encoded as 2^tm_wday, with tm_wday in 0..6, so
using tm_wday = ffs(reg) to fill tm_wday from the register value is
wrong because this gives the expected value + 1. This could be fixed as
tm_wday = ffs(reg) - 1, but tm_wday = ilog2(reg) works as well and is
more direct.

Signed-off-by: Benoît Thébaudeau <benoit@wsystem.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
2016-07-28 09:59:37 +02:00
Benoît Thébaudeau 96acb25c50 rtc: rv8803: Remove the check for valid time
The RTC core always calls rtc_valid_tm() after ->read_time() in case of
success (in __rtc_read_time()), so do not call it twice.

Signed-off-by: Benoît Thébaudeau <benoit@wsystem.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
2016-07-28 09:59:33 +02:00
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
Alexandre Belloni cde0fe2acd rtc: rv8803: broaden workaround
The previous workaround may still fail as there are actually 4 retries to
be done to ensure the communication succeed. Also, some I2C adapter drivers
may return -EIO instead of -ENXIO.

Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
2016-06-26 01:26:16 +02:00
Alexandre Belloni 85062c9b99 rtc: rv8803: workaround i2c HW issue
The rv8803 has a 60µs window where it will not answer on the i2c bus.
It also means there will be no ack for the communication. Make sure
communication is tried multiple times when this happens (the i2c subsystem
mandates -ENXIO is that case but the number of retries is host specific).
The critical parts are the probe function and the alarm callback so make
sure we handle the failure there.

Cc: stable@vger.kernel.org # v4.4
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
2016-03-25 02:38:59 +01:00
Oleksij Rempel 9d1fa4c373 rtc: rv8803: convert spin_lock to mutex_lock
Fix a scheduling while atomic issue caused by rv8803_set_time()
holding a spinlock during the call to i2c_smbus_read_byte_data().

Signed-off-by: Oleksij Rempel <fixed-term.Oleksij.Rempel@de.bosch.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
2016-03-14 17:08:15 +01:00
Gregory CLEMENT 78ef5f2d2d rtc: rv8803: Extend compatibility with the rx8900
The Seiko Epson's RTC RX8900 layout register is compatible with the
RV8803. So let's add its ID in order to reuse the same driver.

Signed-off-by: Gregory CLEMENT <gregory.clement@free-electrons.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
2016-01-11 20:20:00 +01:00
Andrzej Hajda 68c85f2916 rtc: rv8803: fix handling return value of i2c_smbus_read_byte_data
The function can return negative values, so its result should
be assigned to signed variable.

The problem has been detected using proposed semantic patch
scripts/coccinelle/tests/assign_signed_to_unsigned.cocci [1].

[1]: http://permalink.gmane.org/gmane.linux.kernel/2046107

Signed-off-by: Andrzej Hajda <a.hajda@samsung.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
2016-01-11 20:20:00 +01:00
Alexandre Belloni 1e3929ef0e rtc: Add a driver for Micro Crystal RV8803
This driver supports the following functions:
 - reading and settings time
 - alarms when connected to an IRQ
 - reading and clearing the voltage low flags
 - nvram

Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
2015-11-08 14:12:32 +01:00