Merge tag 'timers-core-2022-01-13' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull timer updates from Thomas Gleixner:
 "Updates for the time(r) subsystem:

  Core:

   - Make the clocksource watchdog more robust by better validation
     checks of the measurement.

  Drivers:

   - New drivers for MStar and SSD20xd SOCs

   - The usual cleanups and improvements all over the place"

* tag 'timers-core-2022-01-13' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  dt-bindings: timer: Add Mstar MSC313e timer devicetree bindings documentation
  clocksource/drivers/msc313e: Add support for ssd20xd-based platforms
  clocksource/drivers: Add MStar MSC313e timer support
  clocksource/drivers/pistachio: Fix -Wunused-but-set-variable warning
  clocksource/drivers/timer-imx-sysctr: Set cpumask to cpu_possible_mask
  clocksource/drivers/imx-sysctr: Mark two variable with __ro_after_init
  clocksource/drivers/renesas,ostm: Make RENESAS_OSTM symbol visible
  clocksource/drivers/renesas-ostm: Add RZ/G2L OSTM support
  dt-bindings: timer: renesas: ostm: Document Renesas RZ/G2L OSTM
  clocksource/drivers/exynos_mct: Fix silly typo resulting in checkpatch warning
  clocksource: Reduce the default clocksource_watchdog() retries to 2
  clocksource: Avoid accidental unstable marking of clocksources
  dt-bindings: timer: tpm-timer: Add imx8ulp compatible string
  reset: Add of_reset_control_get_optional_exclusive()
  clocksource/drivers/exynos_mct: Refactor resources allocation
  dt-bindings: timer: remove rockchip,rk3066-timer compatible string from rockchip,rk-timer.yaml
  dt-bindings: timer: cadence_ttc: Add power-domains

1 files changed, 20 insertions, 0 deletions

diff --git a/include/linux/reset.h b/include/linux/reset.h
index db0e6115a2f6..8a21b5756c3e 100644
--- a/include/linux/reset.h
+++ b/include/linux/reset.h
@@ -455,6 +455,26 @@ static inline struct reset_control *of_reset_control_get_exclusive(
 }
 
 /**
+ * of_reset_control_get_optional_exclusive - Lookup and obtain an optional exclusive
+ *                                           reference to a reset controller.
+ * @node: device to be reset by the controller
+ * @id: reset line name
+ *
+ * Optional variant of of_reset_control_get_exclusive(). If the requested reset
+ * is not specified in the device tree, this function returns NULL instead of
+ * an error.
+ *
+ * Returns a struct reset_control or IS_ERR() condition containing errno.
+ *
+ * Use of id names is optional.
+ */
+static inline struct reset_control *of_reset_control_get_optional_exclusive(
+				struct device_node *node, const char *id)
+{
+	return __of_reset_control_get(node, id, 0, false, true, true);
+}
+
+/**
  * of_reset_control_get_shared - Lookup and obtain a shared reference
  *                               to a reset controller.
  * @node: device to be reset by the controller