Merge tag 'regulator-v5.14' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/regulator

Pull regulator updates from Mark Brown:
 "The main core change this release is generic support for handling of
  hardware errors from Matti Vaittinen, including some small updates to
  the reboot and thermal code so we can share support for powering off
  the system if things are going wrong enough.

  Otherwise this release we've mainly seen the addition of new drivers,
  including MT6359 which has pulled in some small changes from the MFD
  tree for build dependencies.

   - Support for controlling the trigger points for hardware error
     detection, and shared handlers for this.

   - Support for Maxim MAX8993, Mediatek MT6359 and MT6359P, Qualcomm
     PM8226 and SA8115P-ADP, and Sylergy TCS4526"

* tag 'regulator-v5.14' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/regulator: (91 commits)
  regulator: bd9576: Fix uninitializes variable may_have_irqs
  regulator: max8893: Select REGMAP_I2C to fix build error
  regulator: da9052: Ensure enough delay time for .set_voltage_time_sel
  regulator: mt6358: Fix vdram2 .vsel_mask
  regulator: hi6421v600: Fix setting wrong driver_data
  MAINTAINERS: Add reviewer for regulator irq_helpers
  regulator: bd9576: Fix the driver name in id table
  regulator: bd9576: Support error reporting
  regulator: bd9576 add FET ON-resistance for OCW
  regulator: add property parsing and callbacks to set protection limits
  regulator: IRQ based event/error notification helpers
  regulator: move rdev_print helpers to internal.h
  regulator: add warning flags
  thermal: Use generic HW-protection shutdown API
  reboot: Add hardware protection power-off
  regulator: Add protection limit properties
  regulator: hi6421v600: Fix setting idle mode
  regulator: Add MAX8893 bindings
  regulator: max8893: add regulator driver
  regulator: hi6421: Use correct variable type for regmap api val argument
  ...

1 files changed, 79 insertions, 0 deletions

diff --git a/kernel/reboot.c b/kernel/reboot.c
index a6ad5eb2fa73..f7440c0c7e43 100644
--- a/kernel/reboot.c
+++ b/kernel/reboot.c
@@ -7,6 +7,7 @@
 
 #define pr_fmt(fmt)	"reboot: " fmt
 
+#include <linux/atomic.h>
 #include <linux/ctype.h>
 #include <linux/export.h>
 #include <linux/kexec.h>
@@ -518,6 +519,84 @@ void orderly_reboot(void)
 }
 EXPORT_SYMBOL_GPL(orderly_reboot);
 
+/**
+ * hw_failure_emergency_poweroff_func - emergency poweroff work after a known delay
+ * @work: work_struct associated with the emergency poweroff function
+ *
+ * This function is called in very critical situations to force
+ * a kernel poweroff after a configurable timeout value.
+ */
+static void hw_failure_emergency_poweroff_func(struct work_struct *work)
+{
+	/*
+	 * We have reached here after the emergency shutdown waiting period has
+	 * expired. This means orderly_poweroff has not been able to shut off
+	 * the system for some reason.
+	 *
+	 * Try to shut down the system immediately using kernel_power_off
+	 * if populated
+	 */
+	pr_emerg("Hardware protection timed-out. Trying forced poweroff\n");
+	kernel_power_off();
+
+	/*
+	 * Worst of the worst case trigger emergency restart
+	 */
+	pr_emerg("Hardware protection shutdown failed. Trying emergency restart\n");
+	emergency_restart();
+}
+
+static DECLARE_DELAYED_WORK(hw_failure_emergency_poweroff_work,
+			    hw_failure_emergency_poweroff_func);
+
+/**
+ * hw_failure_emergency_poweroff - Trigger an emergency system poweroff
+ *
+ * This may be called from any critical situation to trigger a system shutdown
+ * after a given period of time. If time is negative this is not scheduled.
+ */
+static void hw_failure_emergency_poweroff(int poweroff_delay_ms)
+{
+	if (poweroff_delay_ms <= 0)
+		return;
+	schedule_delayed_work(&hw_failure_emergency_poweroff_work,
+			      msecs_to_jiffies(poweroff_delay_ms));
+}
+
+/**
+ * hw_protection_shutdown - Trigger an emergency system poweroff
+ *
+ * @reason:		Reason of emergency shutdown to be printed.
+ * @ms_until_forced:	Time to wait for orderly shutdown before tiggering a
+ *			forced shudown. Negative value disables the forced
+ *			shutdown.
+ *
+ * Initiate an emergency system shutdown in order to protect hardware from
+ * further damage. Usage examples include a thermal protection or a voltage or
+ * current regulator failures.
+ * NOTE: The request is ignored if protection shutdown is already pending even
+ * if the previous request has given a large timeout for forced shutdown.
+ * Can be called from any context.
+ */
+void hw_protection_shutdown(const char *reason, int ms_until_forced)
+{
+	static atomic_t allow_proceed = ATOMIC_INIT(1);
+
+	pr_emerg("HARDWARE PROTECTION shutdown (%s)\n", reason);
+
+	/* Shutdown should be initiated only once. */
+	if (!atomic_dec_and_test(&allow_proceed))
+		return;
+
+	/*
+	 * Queue a backup emergency shutdown in the event of
+	 * orderly_poweroff failure
+	 */
+	hw_failure_emergency_poweroff(ms_until_forced);
+	orderly_poweroff(true);
+}
+EXPORT_SYMBOL_GPL(hw_protection_shutdown);
+
 static int __init reboot_setup(char *str)
 {
 	for (;;) {