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
  ...

include/asm-generic/rtc.h

@@ -16,6 +16,9 @@
 #include <linux/rtc.h>
 #include <linux/bcd.h>
 #include <linux/delay.h>
+#ifdef CONFIG_ACPI
+#include <linux/acpi.h>
+#endif
 
 #define RTC_PIE 0x40		/* periodic interrupt enable */
 #define RTC_AIE 0x20		/* alarm interrupt enable */
@@ -46,6 +49,7 @@ static inline unsigned int __get_rtc_time(struct rtc_time *time)
 {
 	unsigned char ctrl;
 	unsigned long flags;
+	unsigned char century = 0;
 
 #ifdef CONFIG_MACH_DECSTATION
 	unsigned int real_year;
@@ -78,6 +82,11 @@ static inline unsigned int __get_rtc_time(struct rtc_time *time)
 	time->tm_year = CMOS_READ(RTC_YEAR);
 #ifdef CONFIG_MACH_DECSTATION
 	real_year = CMOS_READ(RTC_DEC_YEAR);
+#endif
+#ifdef CONFIG_ACPI
+	if (acpi_gbl_FADT.header.revision >= FADT2_REVISION_ID &&
+	    acpi_gbl_FADT.century)
+		century = CMOS_READ(acpi_gbl_FADT.century);
 #endif
 	ctrl = CMOS_READ(RTC_CONTROL);
 	spin_unlock_irqrestore(&rtc_lock, flags);
@@ -90,12 +99,16 @@ static inline unsigned int __get_rtc_time(struct rtc_time *time)
 		time->tm_mday = bcd2bin(time->tm_mday);
 		time->tm_mon = bcd2bin(time->tm_mon);
 		time->tm_year = bcd2bin(time->tm_year);
+		century = bcd2bin(century);
 	}
 
 #ifdef CONFIG_MACH_DECSTATION
 	time->tm_year += real_year - 72;
 #endif
 
+	if (century)
+		time->tm_year += (century - 19) * 100;
+
 	/*
 	 * Account for differences between how the RTC uses the values
 	 * and how they are defined in a struct rtc_time;
@@ -122,6 +135,7 @@ static inline int __set_rtc_time(struct rtc_time *time)
 #ifdef CONFIG_MACH_DECSTATION
 	unsigned int real_yrs, leap_yr;
 #endif
+	unsigned char century = 0;
 
 	yrs = time->tm_year;
 	mon = time->tm_mon + 1;   /* tm_mon starts at zero */
@@ -150,6 +164,15 @@ static inline int __set_rtc_time(struct rtc_time *time)
 		yrs = 73;
 	}
 #endif
+
+#ifdef CONFIG_ACPI
+	if (acpi_gbl_FADT.header.revision >= FADT2_REVISION_ID &&
+	    acpi_gbl_FADT.century) {
+		century = (yrs + 1900) / 100;
+		yrs %= 100;
+	}
+#endif
+
 	/* These limits and adjustments are independent of
 	 * whether the chip is in binary mode or not.
 	 */
@@ -169,6 +192,7 @@ static inline int __set_rtc_time(struct rtc_time *time)
 		day = bin2bcd(day);
 		mon = bin2bcd(mon);
 		yrs = bin2bcd(yrs);
+		century = bin2bcd(century);
 	}
 
 	save_control = CMOS_READ(RTC_CONTROL);
@@ -185,6 +209,11 @@ static inline int __set_rtc_time(struct rtc_time *time)
 	CMOS_WRITE(hrs, RTC_HOURS);
 	CMOS_WRITE(min, RTC_MINUTES);
 	CMOS_WRITE(sec, RTC_SECONDS);
+#ifdef CONFIG_ACPI
+	if (acpi_gbl_FADT.header.revision >= FADT2_REVISION_ID &&
+	    acpi_gbl_FADT.century)
+		CMOS_WRITE(century, acpi_gbl_FADT.century);
+#endif
 
 	CMOS_WRITE(save_control, RTC_CONTROL);
 	CMOS_WRITE(save_freq_select, RTC_FREQ_SELECT);