[ Upstream commit 7ef66122bdb3b839e9f51b76d7e600b6e21ef648 ]
Issue:
- # hwclock -w
hwclock: RTC_SET_TIME: Invalid argument
Why:
- Relative commit: 8b9f9d4dc511 ("regmap: verify if register is
writeable before writing operations"), this patch
will always check for unwritable registers, it will compare reg
with max_register in regmap_writeable.
- The pcf85363/pcf85263 has the capability of address wrapping
which means if you access an address outside the allowed range
(0x00-0x2f) hardware actually wraps the access to a lower address.
The rtc-pcf85363 driver will use this feature to configure the time
and execute 2 actions in the same i2c write operation (stopping the
clock and configure the time). However the driver has also
configured the `regmap maxregister` protection mechanism that will
block accessing addresses outside valid range (0x00-0x2f).
How:
- Split of writing regs to two parts, first part writes control
registers about stop_enable and resets, second part writes
RTC time and date registers.
Signed-off-by: Biwen Li <biwen.li@nxp.com>
Link: https://lore.kernel.org/r/20190829021418.4607-1-biwen.li@nxp.com
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
As per 8.2.6 Setting and reading the time in RTC mode, first stop the clok,
then reset it before setting the date and time registers. Finally, start
the clock.
This uses register address wrap around from 0x2f to 0x00 for efficiency.
This allows to set the clock with a millisecond accuracy (drift is not
corrected in this example):
RTC System
1325388767 1325388767.000029180
1325388768 1325388768.000018362
1325388769 1325388769.000006544
1325388770 1325388769.999992725
1325388771 1325388770.999974544
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
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>
