In the ->set_offset() callback, the 'val' variable is used for two
different purposes at the same time, which is oviously wrong:
- It contains the intermediate value of the SUBU register that must be
written at the end of ->set_offset().
- It is used in the middle of the above calculations to poll the CTL2
register for a specific value.
Let's introduce a 'ctl2' variable just for the readl_poll_timeout()
call and use it there in place of 'var'.
In order to avoid mixing those two variables again, let's rename the
remaining occurences of 'val' into 'subu' and initialize it to 0 to
avoid the uninitialized variable situation reported by Tom Rix and Colin
Ian King already.
Fixes: be4a11cf98 ("rtc: rzn1: Add oscillator offset support")
Reported-by: Tom Rix <trix@redhat.com>
Reported-by: Colin Ian King <colin.i.king@gmail.com>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Link: https://lore.kernel.org/r/20220520082221.488849-1-miquel.raynal@bootlin.com
The RZN1 RTC can compensate the imprecision of the oscillator up to
approximately 190ppm.
Seconds can last slightly shorter or longer depending on the
configuration.
Below ~65ppm of correction, we can change the time spent in a second
every minute, which is the most accurate compensation that the RTC can
offer. Above, the compensation will be active every 20s.
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Link: https://lore.kernel.org/r/20220516082504.33913-5-miquel.raynal@bootlin.com