Merge tag 'rtc-4.6' of git://git.kernel.org/pub/scm/linux/kernel/git/abelloni/linux

Pull RTC updates from Alexandre Belloni:
 "Core:
   - New sysfs interface to set and read clock offset
   - Drivers can now be both I2C and SPI (see pcf2127 and ds3232)

  New drivers:
   - Alphascale ASM9260
   - Epson RX6110SA
   - Maxim max20024 and max77620 (in max77686)
   - Microchip PIC32
   - NXP pcf2129 (in pcf2127)

  Subsystem wide cleanups:
   - remove IRQF_EARLY_RESUME when unecessary

  Drivers:
   - ds1307: clock output, temperature sensor and wakeup-source support
   - ds1685: actually spin forever in poweroff error path
   - ds3232: many cleanups
   - ds3234: merged in ds3232
   - hym8563: fix invalid year calculation
   - max77686: many cleanups
   - max77802 merged in max77686
   - pcf2123: cleanups and offset support
   - pcf85063: cleanups
   - pcf8523: propely handle oscillator stop bit
   - rv3029: many cleanups, trickle charger and temperature sensor support
   - rv8803: convert spin_lock to mutex_lock
   - rx8025: many fixes
   - vr41xx: restore alarm_irq_enable"

* tag 'rtc-4.6' of git://git.kernel.org/pub/scm/linux/kernel/git/abelloni/linux: (86 commits)
  rtc: pcf2127: add pcf2129 device id
  rtc: pcf2127: add support for spi interface
  rtc: pcf2127: convert to use regmap
  rtc: rv3029: Add thermometer hwmon support
  rtc: rv3029: Add update_bits helper for eeprom access
  rtc: ds1685: actually spin forever in poweroff error path
  rtc: hym8563: fix invalid year calculation
  rtc: ds3232: use rtc->ops_lock to protect alarm operations
  rtc: ds3232: fix issue when irq is shared several devices
  rtc: ds3232: remove unused UIE code
  rtc: ds3232: add register access error checks
  rtc: ds3232: fix read on /dev/rtc after RTC_AIE_ON
  rtc: merge ds3232 and ds3234
  rtc: ds3232: convert to use regmap
  rtc: pxa: fix Kconfig indentation
  rtc: rv3029: Add device tree property for trickle charger
  rtc: rv3029: Add functions for EEPROM access
  rtc: rv3029: Add i2c register update-bits helper
  rtc: rv3029: Add missing register definitions
  rtc: rv3029: Add "rv3029" I2C device id
  ...

1 files changed, 54 insertions, 0 deletions

diff --git a/drivers/rtc/interface.c b/drivers/rtc/interface.c
index 5836751b8203..9ef5f6f89f98 100644
--- a/drivers/rtc/interface.c
+++ b/drivers/rtc/interface.c
@@ -939,4 +939,58 @@ void rtc_timer_cancel(struct rtc_device *rtc, struct rtc_timer *timer)
 	mutex_unlock(&rtc->ops_lock);
 }
 
+/**
+ * rtc_read_offset - Read the amount of rtc offset in parts per billion
+ * @ rtc: rtc device to be used
+ * @ offset: the offset in parts per billion
+ *
+ * see below for details.
+ *
+ * Kernel interface to read rtc clock offset
+ * Returns 0 on success, or a negative number on error.
+ * If read_offset() is not implemented for the rtc, return -EINVAL
+ */
+int rtc_read_offset(struct rtc_device *rtc, long *offset)
+{
+	int ret;
+
+	if (!rtc->ops)
+		return -ENODEV;
+
+	if (!rtc->ops->read_offset)
+		return -EINVAL;
+
+	mutex_lock(&rtc->ops_lock);
+	ret = rtc->ops->read_offset(rtc->dev.parent, offset);
+	mutex_unlock(&rtc->ops_lock);
+	return ret;
+}
 
+/**
+ * rtc_set_offset - Adjusts the duration of the average second
+ * @ rtc: rtc device to be used
+ * @ offset: the offset in parts per billion
+ *
+ * Some rtc's allow an adjustment to the average duration of a second
+ * to compensate for differences in the actual clock rate due to temperature,
+ * the crystal, capacitor, etc.
+ *
+ * Kernel interface to adjust an rtc clock offset.
+ * Return 0 on success, or a negative number on error.
+ * If the rtc offset is not setable (or not implemented), return -EINVAL
+ */
+int rtc_set_offset(struct rtc_device *rtc, long offset)
+{
+	int ret;
+
+	if (!rtc->ops)
+		return -ENODEV;
+
+	if (!rtc->ops->set_offset)
+		return -EINVAL;
+
+	mutex_lock(&rtc->ops_lock);
+	ret = rtc->ops->set_offset(rtc->dev.parent, offset);
+	mutex_unlock(&rtc->ops_lock);
+	return ret;
+}