Commit Graph

16 Commits

Author SHA1 Message Date
Alexandre Belloni
244cf8f0ed rtc: pcf8523: return meaningful value for RTC_VL_READ
REG_CONTROL3_BLF indicates the battery is low and needs to be replaced
soon.

Link: https://lore.kernel.org/r/20191214220259.621996-6-alexandre.belloni@bootlin.com
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
2019-12-18 10:37:25 +01:00
Nobuhiro Iwamatsu
93966243cf rtc: pcf8523: Remove struct pcf8523
struct pcf8523 is referenced only by pcf8523_probe(). And member variable in
this is not referenced by any function. Remove struct pcf8523.

Signed-off-by: Nobuhiro Iwamatsu <iwamatsu@nigauri.org>
Link: https://lore.kernel.org/r/20191123090838.1619-1-nobuhiro1.iwamatsu@toshiba.co.jp
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
2019-11-27 09:31:14 +01:00
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
Sam Ravnborg
189927e719 rtc: pcf8523: set xtal load capacitance from DT
Add support for specifying the xtal load capacitance in the DT node.
The pcf8523 supports xtal load capacitance of 7pF or 12.5pF.
If the rtc has the wrong configuration the time will
drift several hours/week.

The driver use the default value 12.5pF.

The DT may specify either 7000fF or 12500fF.
(The DT uses femto Farad to avoid decimal numbers).
Other values are warned and the driver uses the default value.

Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Cc: Alessandro Zummo <a.zummo@towertech.it>
Cc: Alexandre Belloni <alexandre.belloni@bootlin.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
2019-01-22 18:57:08 +01:00
Alexandre Belloni
7c617e0c5f rtc: pcf8523: Add rv8523 compatible
The Microcrystal RV-8523 is compatible with the PCF8523.

Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
2019-01-10 21:51:24 +01:00
Baruch Siach
ecb4a353d3 rtc: pcf8523: don't return invalid date when battery is low
The RTC_VL_READ ioctl reports the low battery condition. Still,
pcf8523_rtc_read_time() happily returns invalid dates in this case.
Check the battery health on pcf8523_rtc_read_time() to avoid that.

Reported-by: Erik Čuk <erik.cuk@domel.com>
Signed-off-by: Baruch Siach <baruch@tkos.co.il>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
2018-12-11 00:46:53 +01:00
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
Russell King
bc3bee0252 rtc: pcf8523: add support for trimming the RTC oscillator
Add support for reading and writing the RTC offset register, converting
it to the corresponding parts-per-billion value.

When setting the drift, the PCF8523 has two modes: one applies the
adjustment every two hours, the other applies the adjustment every
minute.  We select between these two modes according to which ever
gives the closest PPB value to the one requested.

Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
2017-10-25 23:05:52 +02:00
Alexandre Belloni
ede44c908d rtc: pcf8523: properly handle oscillator stop bit
The time and date register of the pcf8223 are undefined after a power
reset. Properly handle the OS bit and return -EINVAL when that bit is set.

It is properly removed when setting the time.

This solves an issue where the time and date may be valid for
rtc_valid_tm() but is not the current time.

Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
2016-03-14 17:08:30 +01:00
Uwe Kleine-König
fbbf53f702 rtc: pcf8523: refuse to write dates later than 2099
When the chip increments the YEAR register and it already holds
bin2bcd(99) it reads as 0 afterwards. With this behaviour the last valid
day (without trickery) that has a representation is 2099-12-31 23:59:59.
So refuse to write later dates.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
2016-01-11 20:19:54 +01:00
Krzysztof Kozlowski
b28845433e rtc: Drop owner assignment from i2c_driver
i2c_driver does not need to set an owner because i2c_register_driver()
will set it.

Signed-off-by: Krzysztof Kozlowski <k.kozlowski@samsung.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
2015-09-05 13:19:06 +02:00
Chris Cui
35738392b6 drivers/rtc/rtc-pcf8523.c: fix month definition
PCF8523 uses 1-12 to represent month according to datasheet.
link: www.nxp.com/documents/data_sheet/PCF8523.pdf.

Signed-off-by: Chris Cui <chris.wei.cui@gmail.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>
2014-05-06 13:04:58 -07:00
Sachin Kamat
af99ef9ccc drivers/rtc/rtc-pcf8523.c: remove empty function
After the switch to devm_* functions and the removal of
rtc_device_unregister(), the 'remove' function does not do anything.
Delete it.

Signed-off-by: Sachin Kamat <sachin.kamat@linaro.org>
Acked-by: Thierry Reding <thierry.reding@avionic-design.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-07-03 16:07:57 -07:00
Jingoo Han
288031bfef rtc: rtc-pcf8523: use devm_rtc_device_register()
devm_rtc_device_register() is device managed and makes cleanup
paths simpler.

Signed-off-by: Jingoo Han <jg1.han@samsung.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-04-29 18:28:26 -07:00
Jesper Nilsson
f32bc70d5f rtc-pcf8523: add low battery voltage support
Implement reading of the battery voltage low signal for rtc-pcf8523.

The bit is read-only and cannot be cleared by software, so no
clear function is implemented.

[akpm@linux-foundation.org: omit pcf8563_rtc_ioctl() if CONFIG_RTC_INTF_DEV=n]
Signed-off-by: Jesper Nilsson <jesper.nilsson@axis.com>
Reviewed-by: Thierry Reding <thierry.reding@avionic-design.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-02-21 17:22:27 -08:00
Thierry Reding
f803f0d079 rtc: add NXP PCF8523 support
Add an RTC driver for PCF8523 chips by NXP Semiconductors.  No support is
currently provided for the alarm and interrupt functions.  Only the time
and date functionality is implemented.

Signed-off-by: Thierry Reding <thierry.reding@avionic-design.de>
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>
2012-12-17 17:15:21 -08:00