On 29/08/2019 10:14:18+0800, Biwen Li wrote: > Issue: > - # hwclock -w > hwclock: RTC_SET_TIME: Invalid argument > > Why: > - Relative commit: 8b9f9d4dc511309918c4f6793bae7387c0c638af, 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@xxxxxxx> > --- > Change in v5: > - drop robust explanation > > Change in v4: > - use old scheme > - replace link to lkml.org with commit > - add proper explanation > > Change in v3: > - replace old scheme with new scheme: > increase max_register. > > Change in v2: > - add Why and How into commit message. > > drivers/rtc/rtc-pcf85363.c | 7 ++++++- > 1 file changed, 6 insertions(+), 1 deletion(-) > Applied, thanks. -- Alexandre Belloni, Bootlin Embedded Linux and Kernel engineering https://bootlin.com
