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| author | Biwen Li <biwen.li@nxp.com> | 2019-08-29 05:14:18 +0300 |
|---|---|---|
| committer | Alexandre Belloni <alexandre.belloni@bootlin.com> | 2019-09-01 09:48:28 +0300 |
| commit | 7ef66122bdb3b839e9f51b76d7e600b6e21ef648 (patch) | |
| tree | b45f2b2cd51840d0c4b3fa0504849a9cade156b0 /drivers/rtc | |
| parent | c59a9fc7272e56ba0575b9fcc346c5e4bf16b39d (diff) | |
| download | linux-7ef66122bdb3b839e9f51b76d7e600b6e21ef648.tar.xz | |
rtc: pcf85363/pcf85263: fix regmap error in set_time
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: Biwen Li <biwen.li@nxp.com>
Link: https://lore.kernel.org/r/20190829021418.4607-1-biwen.li@nxp.com
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Diffstat (limited to 'drivers/rtc')
| -rw-r--r-- | drivers/rtc/rtc-pcf85363.c | 7 |
1 files changed, 6 insertions, 1 deletions
diff --git a/drivers/rtc/rtc-pcf85363.c b/drivers/rtc/rtc-pcf85363.c index a075e77617dc..3450d615974d 100644 --- a/drivers/rtc/rtc-pcf85363.c +++ b/drivers/rtc/rtc-pcf85363.c @@ -166,7 +166,12 @@ static int pcf85363_rtc_set_time(struct device *dev, struct rtc_time *tm) buf[DT_YEARS] = bin2bcd(tm->tm_year % 100); ret = regmap_bulk_write(pcf85363->regmap, CTRL_STOP_EN, - tmp, sizeof(tmp)); + tmp, 2); + if (ret) + return ret; + + ret = regmap_bulk_write(pcf85363->regmap, DT_100THS, + buf, sizeof(tmp) - 2); if (ret) return ret; |