Re: [v5] rtc: pcf85363/pcf85263: fix error that failed to run hwclock -w

[Nandor Han]

On 8/29/19 5:14 AM, 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

LGTM +1

Nandor