Merge tag 'rtc-4.17' of git://git.kernel.org/pub/scm/linux/kernel/git/abelloni/linux

Pull RTC updates from Alexandre Belloni:
 "This contains a few series that have been in preparation for a while
  and that will help systems with RTCs that will fail in 2038, 2069 or
  2100.

  Subsystem:
   - Add tracepoints
   - Rework of the RTC/nvmem API to allow drivers to discard struct
     nvmem_config after registration
   - New range API, drivers can now expose the useful range of the RTC
   - New offset API the core is now able to add an offset to the RTC
     time, modifying the supported range.
   - Multiple rtc_time64_to_tm fixes
   - Handle time_t overflow on 32 bit platforms in the core instead of
     letting drivers do crazy things.
   - remove rtc_control API

  New driver:
   - Intersil ISL12026

  Drivers:
   - Drivers exposing the RTC non volatile memory have been converted to
     use nvmem
   - Removed useless time and date validation
   - Removed an indirection pattern that was a cargo cult from ancient
     drivers
   - Removed VLA usage
   - Fixed a possible race condition in probe functions
   - AB8540 support is dropped from ab8500
   - pcf85363 now has alarm support"

* tag 'rtc-4.17' of git://git.kernel.org/pub/scm/linux/kernel/git/abelloni/linux: (128 commits)
  rtc: snvs: Fix usage of snvs_rtc_enable
  rtc: mt7622: fix module autoloading for OF platform drivers
  rtc: isl12022: use true and false for boolean values
  rtc: ab8500: Drop AB8540 support
  rtc: remove a warning during scripts/kernel-doc step
  rtc: 88pm860x: remove artificial limitation
  rtc: 88pm80x: remove artificial limitation
  rtc: st-lpc: remove artificial limitation
  rtc: mrst: remove artificial limitation
  rtc: mv: remove artificial limitation
  rtc: hctosys: Ensure system time doesn't overflow time_t
  parisc: time: stop validating rtc_time in .read_time
  rtc: pcf85063: fix clearing bits in pcf85063_start_clock
  rtc: at91sam9: Set name of regmap_config
  rtc: s5m: Remove VLA usage
  rtc: s5m: Move enum from rtc.h to rtc-s5m.c
  rtc: remove VLA usage
  rtc: Add useful timestamp definitions
  rtc: Add one offset seconds to expand RTC range
  rtc: Factor out the RTC range validation into rtc_valid_range()
  ...

1 files changed, 24 insertions, 2 deletions

diff --git a/drivers/rtc/rtc-ac100.c b/drivers/rtc/rtc-ac100.c
index 8ff9dc3fe5bf..3fe576fdd45e 100644
--- a/drivers/rtc/rtc-ac100.c
+++ b/drivers/rtc/rtc-ac100.c
@@ -183,7 +183,29 @@ static int ac100_clkout_determine_rate(struct clk_hw *hw,
 
 	for (i = 0; i < num_parents; i++) {
 		struct clk_hw *parent = clk_hw_get_parent_by_index(hw, i);
-		unsigned long tmp, prate = clk_hw_get_rate(parent);
+		unsigned long tmp, prate;
+
+		/*
+		 * The clock has two parents, one is a fixed clock which is
+		 * internally registered by the ac100 driver. The other parent
+		 * is a clock from the codec side of the chip, which we
+		 * properly declare and reference in the devicetree and is
+		 * not implemented in any driver right now.
+		 * If the clock core looks for the parent of that second
+		 * missing clock, it can't find one that is registered and
+		 * returns NULL.
+		 * So we end up in a situation where clk_hw_get_num_parents
+		 * returns the amount of clocks we can be parented to, but
+		 * clk_hw_get_parent_by_index will not return the orphan
+		 * clocks.
+		 * Thus we need to check if the parent exists before
+		 * we get the parent rate, so we could use the RTC
+		 * without waiting for the codec to be supported.
+		 */
+		if (!parent)
+			continue;
+
+		prate = clk_hw_get_rate(parent);
 
 		tmp = ac100_clkout_round_rate(hw, req->rate, prate);
 
@@ -387,7 +409,7 @@ static int ac100_rtc_get_time(struct device *dev, struct rtc_time *rtc_tm)
 	rtc_tm->tm_year = bcd2bin(reg[6] & AC100_RTC_YEA_MASK) +
 			  AC100_YEAR_OFF;
 
-	return rtc_valid_tm(rtc_tm);
+	return 0;
 }
 
 static int ac100_rtc_set_time(struct device *dev, struct rtc_time *rtc_tm)