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    rtc: pcf85363/pcf85263: fix regmap error in set_time · 31e98cba
    Biwen Li 提交于
    [ 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: NBiwen Li <biwen.li@nxp.com>
    Link: https://lore.kernel.org/r/20190829021418.4607-1-biwen.li@nxp.comSigned-off-by: NAlexandre Belloni <alexandre.belloni@bootlin.com>
    Signed-off-by: NSasha Levin <sashal@kernel.org>
    31e98cba
rtc-pcf85363.c 9.5 KB