From: Biwen Li <biwen.li@nxp.com>
To: a.zummo@towertech.it, alexandre.belloni@bootlin.com,
leoyang.li@nxp.com, broonie@kernel.org, nandor.han@vaisala.com
Cc: linux-rtc@vger.kernel.org, linux-kernel@vger.kernel.org,
Biwen Li <biwen.li@nxp.com>
Subject: [v4] rtc: pcf85363/pcf85263: fix error that failed to run hwclock -w
Date: Tue, 27 Aug 2019 12:37:35 +0800 [thread overview]
Message-ID: <20190827043735.31231-1-biwen.li@nxp.com> (raw)
Issue:
- # hwclock -w
hwclock: RTC_SET_TIME: Invalid argument
Why:
- Relative commit: 8b9f9d4dc511309918c4f6793bae7387c0c638af, this patch
will always check for unwritable registers, it will compare reg
with max_register in regmap_writeable.
- 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.
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>
---
Change in v4:
- use old scheme
- replace link to lkml.org with commit
- add proper explanation
Change in v3:
- replace old scheme with new scheme:
increase max_register.
Change in v2:
- add Why and How into commit message.
drivers/rtc/rtc-pcf85363.c | 7 ++++++-
1 file changed, 6 insertions(+), 1 deletion(-)
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;
--
2.17.1
next reply other threads:[~2019-08-27 4:47 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-08-27 4:37 Biwen Li [this message]
2019-08-27 8:07 ` [v4] rtc: pcf85363/pcf85263: fix error that failed to run hwclock -w Nandor Han
2019-08-27 8:12 ` [EXT] " Biwen Li
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20190827043735.31231-1-biwen.li@nxp.com \
--to=biwen.li@nxp.com \
--cc=a.zummo@towertech.it \
--cc=alexandre.belloni@bootlin.com \
--cc=broonie@kernel.org \
--cc=leoyang.li@nxp.com \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-rtc@vger.kernel.org \
--cc=nandor.han@vaisala.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).