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authorBiwen Li <biwen.li@nxp.com>2019-08-29 10:14:18 +0800
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2019-10-07 18:57:12 +0200
commit31e98cba55edc3986a1094df401074d01d5e064f (patch)
parent607f95788fa94d15538ffdf6bbfa53eb3af2cfa6 (diff)
rtc: pcf85363/pcf85263: fix regmap error in set_time
[ 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: 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> Signed-off-by: Sasha Levin <sashal@kernel.org>
1 files changed, 6 insertions, 1 deletions
diff --git a/drivers/rtc/rtc-pcf85363.c b/drivers/rtc/rtc-pcf85363.c
index c04a1edcd571..c3702684b342 100644
--- a/drivers/rtc/rtc-pcf85363.c
+++ b/drivers/rtc/rtc-pcf85363.c
@@ -169,7 +169,12 @@ 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;