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From: Alexandre Belloni <alexandre.belloni@bootlin.com>
To: linux-rtc@vger.kernel.org
Cc: linux-kernel@vger.kernel.org,
	Alexandre Belloni <alexandre.belloni@bootlin.com>
Subject: [PATCH 11/16] rtc: rv3029: correctly handle PON and VLOW2
Date: Sat, 14 Dec 2019 23:10:17 +0100	[thread overview]
Message-ID: <20191214221022.622482-12-alexandre.belloni@bootlin.com> (raw)
In-Reply-To: <20191214221022.622482-1-alexandre.belloni@bootlin.com>

In case the data is invalid (PON or VLOW2 are set in STATUS, explicitly
tell userspace that the time is invalid. Only remove VLOW2 when setting a
new valid time.

Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
---
 drivers/rtc/rtc-rv3029c2.c | 21 +++++++++++++++------
 1 file changed, 15 insertions(+), 6 deletions(-)

diff --git a/drivers/rtc/rtc-rv3029c2.c b/drivers/rtc/rtc-rv3029c2.c
index 6ae96baa111a..433aad16897e 100644
--- a/drivers/rtc/rtc-rv3029c2.c
+++ b/drivers/rtc/rtc-rv3029c2.c
@@ -159,20 +159,21 @@ static int rv3029_eeprom_enter(struct rv3029_data *rv3029)
 	ret = regmap_read(rv3029->regmap, RV3029_STATUS, &sr);
 	if (ret < 0)
 		return ret;
-	if (sr & (RV3029_STATUS_VLOW1 | RV3029_STATUS_VLOW2)) {
+	if (sr & RV3029_STATUS_VLOW2)
+		return -ENODEV;
+	if (sr & RV3029_STATUS_VLOW1) {
 		/* We clear the bits and retry once just in case
 		 * we had a brown out in early startup.
 		 */
 		ret = regmap_update_bits(rv3029->regmap, RV3029_STATUS,
-					 RV3029_STATUS_VLOW1 |
-					 RV3029_STATUS_VLOW2, 0);
+					 RV3029_STATUS_VLOW1, 0);
 		if (ret < 0)
 			return ret;
 		usleep_range(1000, 10000);
 		ret = regmap_read(rv3029->regmap, RV3029_STATUS, &sr);
 		if (ret < 0)
 			return ret;
-		if (sr & (RV3029_STATUS_VLOW1 | RV3029_STATUS_VLOW2)) {
+		if (sr & RV3029_STATUS_VLOW1) {
 			dev_err(rv3029->dev,
 				"Supply voltage is too low to safely access the EEPROM.\n");
 			return -ENODEV;
@@ -306,9 +307,17 @@ static irqreturn_t rv3029_handle_irq(int irq, void *dev_id)
 static int rv3029_read_time(struct device *dev, struct rtc_time *tm)
 {
 	struct rv3029_data *rv3029 = dev_get_drvdata(dev);
+	unsigned int sr;
 	int ret;
 	u8 regs[RV3029_WATCH_SECTION_LEN] = { 0, };
 
+	ret = regmap_read(rv3029->regmap, RV3029_STATUS, &sr);
+	if (ret < 0)
+		return ret;
+
+	if (sr & (RV3029_STATUS_VLOW2 | RV3029_STATUS_PON))
+		return -EINVAL;
+
 	ret = regmap_bulk_read(rv3029->regmap, RV3029_W_SEC, regs,
 			       RV3029_WATCH_SECTION_LEN);
 	if (ret < 0) {
@@ -454,9 +463,9 @@ static int rv3029_set_time(struct device *dev, struct rtc_time *tm)
 	if (ret < 0)
 		return ret;
 
-	/* clear PON bit */
+	/* clear PON and VLOW2 bits */
 	return regmap_update_bits(rv3029->regmap, RV3029_STATUS,
-				  RV3029_STATUS_PON, 0);
+				  RV3029_STATUS_PON | RV3029_STATUS_VLOW2, 0);
 }
 
 static int rv3029_ioctl(struct device *dev, unsigned int cmd, unsigned long arg)
-- 
2.23.0


  parent reply	other threads:[~2019-12-14 22:10 UTC|newest]

Thread overview: 17+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-12-14 22:10 [PATCH 00/16] rtc: rv3029: cleanup and features Alexandre Belloni
2019-12-14 22:10 ` [PATCH 01/16] rtc: rv3029: use proper name for the driver Alexandre Belloni
2019-12-14 22:10 ` [PATCH 02/16] rtc: rv3029: let regmap validate the register ranges Alexandre Belloni
2019-12-14 22:10 ` [PATCH 03/16] rtc: rv3029: remove open coded regmap_update_bits Alexandre Belloni
2019-12-14 22:10 ` [PATCH 04/16] rtc: rv3029: remove race condition when update STATUS Alexandre Belloni
2019-12-14 22:10 ` [PATCH 05/16] rtc: rv3029: avoid reading the status register uselessly Alexandre Belloni
2019-12-14 22:10 ` [PATCH 06/16] rtc: rv3029: get rid of rv3029_get_sr Alexandre Belloni
2019-12-14 22:10 ` [PATCH 07/16] rtc: rv3029: simplify rv3029_alarm_irq_enable Alexandre Belloni
2019-12-14 22:10 ` [PATCH 08/16] rtc: rv3029: simplify rv3029_set_alarm Alexandre Belloni
2019-12-14 22:10 ` [PATCH 09/16] rtc: rv3029: drop rv3029_read_regs and rv3029_write_regs Alexandre Belloni
2019-12-14 22:10 ` [PATCH 10/16] rtc: rv3029: add RTC_VL_READ and RTC_VL_CLEAR support Alexandre Belloni
2019-12-14 22:10 ` Alexandre Belloni [this message]
2019-12-14 22:10 ` [PATCH 12/16] rtc: rv3029: convert to devm_rtc_allocate_device Alexandre Belloni
2019-12-14 22:10 ` [PATCH 13/16] rtc: rv3029: let the core handle rtc range Alexandre Belloni
2019-12-14 22:10 ` [PATCH 14/16] rtc: rv3029: remove useless error messages Alexandre Belloni
2019-12-14 22:10 ` [PATCH 15/16] rtc: rv3029: annotate init and exit functions Alexandre Belloni
2019-12-14 22:10 ` [PATCH 16/16] rtc: rv3029: add nvram support Alexandre Belloni

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