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...@nxp.com>
---
Change in v5:
        - drop robust explanation

LGTM +1

Nandor