Merge tag 'rtc-v4.3' of git://git.kernel.org/pub/scm/linux/kernel/git/abelloni/linux

Pull RTC updates from Alexandre Belloni:
 "Core:
   - use is_visible() to control sysfs attributes
   - switch wakealarm attribute to DEVICE_ATTR_RW
   - make rtc_does_wakealarm() return boolean
   - properly manage lifetime of dev and cdev in rtc device
   - remove unnecessary device_get() in rtc_device_unregister
   - fix double free in rtc_register_device() error path

  New drivers:
   - NXP LPC24xx
   - Xilinx Zynq MP
   - Dialog DA9062

  Subsystem wide cleanups:
   - fix drivers that consider 0 as a valid IRQ in client->irq
   - Drop (un)likely before IS_ERR(_OR_NULL)
   - drop the remaining owner assignment for i2c_driver and
     platform_driver
   - module autoload fixes

  Drivers:
   - 88pm80x: add device tree support
   - abx80x: fix RTC write bit
   - ab8500: Add a sentinel to ab85xx_rtc_ids[]
   - armada38x: Align RTC set time procedure with the official errata
   - as3722: correct month value
   - at91sam9: cleanups
   - at91rm9200: get and use slow clock and cleanups
   - bq32k: remove redundant check
   - cmos: century support, proper fix for the spurious wakeup
   - ds1307: cleanups and wakeup irq support
   - ds1374: Remove unused variable
   - ds1685: Use module_platform_driver
   - ds3232: fix WARNING trace in resume function
   - gemini: fix ptr_ret.cocci warnings
   - mt6397: implement suspend/resume
   - omap: support internal and external clock enabling
   - opal: Enable alarms only when opal supports tpo
   - pcf2127: use OFS flag to detect unreliable date and warn the user
   - pl031: fix typo for author email
   - rx8025: huge cleanup and fixes
   - sa1100/pxa: share common code
   - s5m: fix to update ctrl register
   - s3c: fix clocks and wakeup, cleanup
   - sirfsoc: use regmap
   - nvram_read()/nvram_write() functions for cmos, ds1305, ds1307,
     ds1343, ds1511, ds1553, ds1742, m48t59, rp5c01, stk17ta8, tx4939
   - use rtc_valid_tm() error code when reading date/time instead of 0
     for isl12022, pcf2123, pcf2127"

* tag 'rtc-v4.3' of git://git.kernel.org/pub/scm/linux/kernel/git/abelloni/linux: (90 commits)
  rtc: abx80x: fix RTC write bit
  rtc: ab8500: Add a sentinel to ab85xx_rtc_ids[]
  rtc: ds1374: Remove unused variable
  rtc: Fix module autoload for OF platform drivers
  rtc: Fix module autoload for rtc-{ab8500,max8997,s5m} drivers
  rtc: omap: Add external clock enabling support
  rtc: omap: Add internal clock enabling support
  ARM: dts: AM437x: Add the internal and external clock nodes for rtc
  rtc: s5m: fix to update ctrl register
  rtc: add xilinx zynqmp rtc driver
  devicetree: bindings: rtc: add bindings for xilinx zynqmp rtc
  rtc: as3722: correct month value
  ARM: config: Switch PXA27x platforms to use PXA RTC driver
  ARM: mmp: remove unused RTC register definitions
  ARM: sa1100: remove unused RTC register definitions
  rtc: sa1100/pxa: convert to run-time register mapping
  ARM: pxa: add memory resource to SA1100 RTC device
  rtc: pxa: convert to use shared sa1100 functions
  rtc: sa1100: prepare to share sa1100_rtc_ops
  rtc: ds3232: fix WARNING trace in resume function
  ...

1 files changed, 24 insertions, 11 deletions

diff --git a/drivers/rtc/rtc-pcf2127.c b/drivers/rtc/rtc-pcf2127.c
index 9bd842e97749..4b11d31f7174 100644
--- a/drivers/rtc/rtc-pcf2127.c
+++ b/drivers/rtc/rtc-pcf2127.c
@@ -33,11 +33,14 @@
 #define PCF2127_REG_MO          (0x08)
 #define PCF2127_REG_YR          (0x09)
 
+#define PCF2127_OSF             BIT(7)  /* Oscillator Fail flag */
+
 static struct i2c_driver pcf2127_driver;
 
 struct pcf2127 {
 	struct rtc_device *rtc;
 	int voltage_low; /* indicates if a low_voltage was detected */
+	int oscillator_failed; /* OSF was detected and date is unreliable */
 };
 
 /*
@@ -59,7 +62,18 @@ static int pcf2127_get_datetime(struct i2c_client *client, struct rtc_time *tm)
 	if (buf[PCF2127_REG_CTRL3] & 0x04) {
 		pcf2127->voltage_low = 1;
 		dev_info(&client->dev,
-			"low voltage detected, date/time is not reliable.\n");
+			"low voltage detected, check/replace RTC battery.\n");
+	}
+
+	if (buf[PCF2127_REG_SC] & PCF2127_OSF) {
+		/*
+		 * no need clear the flag here,
+		 * it will be cleared once the new date is saved
+		 */
+		pcf2127->oscillator_failed = 1;
+		dev_warn(&client->dev,
+			 "oscillator stop detected, date/time is not reliable\n");
+		return -EINVAL;
 	}
 
 	dev_dbg(&client->dev,
@@ -88,17 +102,12 @@ static int pcf2127_get_datetime(struct i2c_client *client, struct rtc_time *tm)
 		tm->tm_sec, tm->tm_min, tm->tm_hour,
 		tm->tm_mday, tm->tm_mon, tm->tm_year, tm->tm_wday);
 
-	/* the clock can give out invalid datetime, but we cannot return
-	 * -EINVAL otherwise hwclock will refuse to set the time on bootup.
-	 */
-	if (rtc_valid_tm(tm) < 0)
-		dev_err(&client->dev, "retrieved date/time is not valid.\n");
-
-	return 0;
+	return rtc_valid_tm(tm);
 }
 
 static int pcf2127_set_datetime(struct i2c_client *client, struct rtc_time *tm)
 {
+	struct pcf2127 *pcf2127 = i2c_get_clientdata(client);
 	unsigned char buf[8];
 	int i = 0, err;
 
@@ -112,7 +121,7 @@ static int pcf2127_set_datetime(struct i2c_client *client, struct rtc_time *tm)
 	buf[i++] = PCF2127_REG_SC;
 
 	/* hours, minutes and seconds */
-	buf[i++] = bin2bcd(tm->tm_sec);
+	buf[i++] = bin2bcd(tm->tm_sec);	/* this will also clear OSF flag */
 	buf[i++] = bin2bcd(tm->tm_min);
 	buf[i++] = bin2bcd(tm->tm_hour);
 	buf[i++] = bin2bcd(tm->tm_mday);
@@ -132,6 +141,9 @@ static int pcf2127_set_datetime(struct i2c_client *client, struct rtc_time *tm)
 		return -EIO;
 	}
 
+	/* clear OSF flag in client data */
+	pcf2127->oscillator_failed = 0;
+
 	return 0;
 }
 
@@ -144,7 +156,9 @@ static int pcf2127_rtc_ioctl(struct device *dev,
 	switch (cmd) {
 	case RTC_VL_READ:
 		if (pcf2127->voltage_low)
-			dev_info(dev, "low voltage detected, date/time is not reliable.\n");
+			dev_info(dev, "low voltage detected, check/replace battery\n");
+		if (pcf2127->oscillator_failed)
+			dev_info(dev, "oscillator stop detected, date/time is not reliable\n");
 
 		if (copy_to_user((void __user *)arg, &pcf2127->voltage_low,
 					sizeof(int)))
@@ -217,7 +231,6 @@ MODULE_DEVICE_TABLE(of, pcf2127_of_match);
 static struct i2c_driver pcf2127_driver = {
 	.driver		= {
 		.name	= "rtc-pcf2127",
-		.owner	= THIS_MODULE,
 		.of_match_table = of_match_ptr(pcf2127_of_match),
 	},
 	.probe		= pcf2127_probe,