Re: [v4] rtc: pcf85363/pcf85263: fix error that failed to run hwclock -w

From: Nandor Han
Date: Tue Aug 27 2019 - 04:07:35 EST


On 8/27/19 7:37 AM, Biwen Li wrote:
- In drivers/rtc/rtc-pcf85363.c, CTRL_STOP_EN is 0x2e, but DT_100THS
is 0, max_regiter is 0x2f, then reg will be equal to 0x30,
'0x30 < 0x2f' is false,so regmap_writeable will return false.

- The pcf85363/pcf85263 has the capability of address wrapping
which means if you access a continuous address range across a
certain boundary(max_register of struct regmap_config) the
hardware actually wraps the access to a lower address. But the
address violation check of regmap rejects such access.

nitpick: This 2 paragraphs could be combined to clear up the issue:

`
The pcf85363/pcf85263 has the capability of address wrapping
which means if you access an address outside the allowed range (0x00-0x2f) the hardware actually wraps the access to a lower address. The rtc-pf85363 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).
`

nitpick: I would also use separate buffers for this actions. Up to you :)

Otherwise LGTM +1

Nandor