From: Philipp Rosenberger <p.rosenberger@kunbus.com>
To: a.zummo@towertech.it, alexandre.belloni@bootlin.com
Cc: p.rosenberger@kunbus.com, dan.carpenter@oracle.com,
u.kleine-koenig@pengutronix.de, biwen.li@nxp.com, lvb@xiphos.com,
bruno.thomsen@gmail.com, l.sanfilippo@kunbus.com,
linux-rtc@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: [PATCH v3 0/2] rtc: pcf2127: proper initialization after power loss
Date: Mon, 18 Jan 2021 09:57:50 +0100 [thread overview]
Message-ID: <20210118085752.5759-1-p.rosenberger@kunbus.com> (raw)
If the PCF2127/2129 loses power it needs some initialization to work
correctly. A bootloader/firmware might do this. If not we should do this
in the driver.
Changes for v3:
- drop the test if clearing PORO was successful
- only run OTP refresh if OTPR bit is not already set
Changes for v2:
- make commit log and comments more clear
- check if PORO was really disabled
Philipp Rosenberger (2):
rtc: pcf2127: Disable Power-On Reset Override
rtc: pcf2127: Run a OTP refresh if not done before
drivers/rtc/rtc-pcf2127.c | 25 +++++++++++++++++++++++++
1 file changed, 25 insertions(+)
Interdiff against v2:
diff --git a/drivers/rtc/rtc-pcf2127.c b/drivers/rtc/rtc-pcf2127.c
index ca56dba64e79..b48fa27cf093 100644
--- a/drivers/rtc/rtc-pcf2127.c
+++ b/drivers/rtc/rtc-pcf2127.c
@@ -568,6 +568,7 @@ static int pcf2127_probe(struct device *dev, struct regmap *regmap,
{
struct pcf2127 *pcf2127;
int ret = 0;
+ unsigned int val;
dev_dbg(dev, "%s\n", __func__);
@@ -622,29 +623,19 @@ static int pcf2127_probe(struct device *dev, struct regmap *regmap,
*/
regmap_clear_bits(pcf2127->regmap, PCF2127_REG_CTRL1,
PCF2127_BIT_CTRL1_POR_OVRD);
- /*
- * If the PORO can't be disabled, just move on. The RTC should
- * work fine, but functions like watchdog and alarm interrupts might
- * not work. There will be no interrupt generated on the interrupt pin.
- */
- ret = regmap_test_bits(pcf2127->regmap, PCF2127_REG_CTRL1, PCF2127_BIT_CTRL1_POR_OVRD);
- if (ret <= 0) {
- dev_err(dev, "%s: can't disable PORO (ctrl1).\n", __func__);
- dev_warn(dev, "Watchdog and alarm functions might not work properly\n");
- }
- /*
- * Set the OTP refresh bit unconditionally. If an OTP refresh was
- * already done the bit is already set and will not rerun the refresh
- * operation.
- */
- ret = regmap_set_bits(pcf2127->regmap, PCF2127_REG_CLKOUT,
- PCF2127_BIT_CLKOUT_OTPR);
- if (ret < 0) {
- dev_err(dev, "%s: OTP refresh (clkout_ctrl) failed.\n", __func__);
+ ret = regmap_read(pcf2127->regmap, PCF2127_REG_CLKOUT, &val);
+ if (ret < 0)
return ret;
+
+ if (!(val & PCF2127_BIT_CLKOUT_OTPR)) {
+ ret = regmap_set_bits(pcf2127->regmap, PCF2127_REG_CLKOUT,
+ PCF2127_BIT_CLKOUT_OTPR);
+ if (ret < 0)
+ return ret;
+
+ msleep(100);
}
- msleep(100);
/*
* Watchdog timer enabled and reset pin /RST activated when timed out.
--
2.29.2
next reply other threads:[~2021-01-18 9:02 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-01-18 8:57 Philipp Rosenberger [this message]
2021-01-18 8:57 ` [PATCH v3 1/2] rtc: pcf2127: Disable Power-On Reset Override Philipp Rosenberger
2021-01-18 9:27 ` Uwe Kleine-König
2021-01-18 8:57 ` [PATCH v3 2/2] rtc: pcf2127: Run a OTP refresh if not done before Philipp Rosenberger
2021-01-25 23:28 ` [PATCH v3 0/2] rtc: pcf2127: proper initialization after power loss Alexandre Belloni
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=20210118085752.5759-1-p.rosenberger@kunbus.com \
--to=p.rosenberger@kunbus.com \
--cc=a.zummo@towertech.it \
--cc=alexandre.belloni@bootlin.com \
--cc=biwen.li@nxp.com \
--cc=bruno.thomsen@gmail.com \
--cc=dan.carpenter@oracle.com \
--cc=l.sanfilippo@kunbus.com \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-rtc@vger.kernel.org \
--cc=lvb@xiphos.com \
--cc=u.kleine-koenig@pengutronix.de \
/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).