regulator: add warning flags

Add 'warning' level events and error flags to regulator core.
Current regulator core notifications are used to inform consumers
about errors where HW is misbehaving in such way it is assumed to
be broken/unrecoverable.

There are PMICs which are designed for system(s) that may have use
for regulator indications sent before HW is damaged so that some
board/consumer specific recovery-event can be performed while
continuing most of the normal operations.

Add new WARNING level events and notifications to be used for
that purpose.
Signed-off-by: Matti Vaittinen <matti.vaittinen@fi.rohmeurope.com>
Link: https://lore.kernel.org/r/9b54aa5589ae4b5945d53d114bac3fae55fa4818.1622628333.git.matti.vaittinen@fi.rohmeurope.comSigned-off-by: Mark Brown <broonie@kernel.org>

include/linux/regulator/consumer.h

@@ -119,6 +119,16 @@ struct regulator_dev;
 #define REGULATOR_EVENT_PRE_DISABLE		0x400
 #define REGULATOR_EVENT_ABORT_DISABLE		0x800
 #define REGULATOR_EVENT_ENABLE			0x1000
+/*
+ * Following notifications should be emitted only if detected condition
+ * is such that the HW is likely to still be working but consumers should
+ * take a recovery action to prevent problems esacalating into errors.
+ */
+#define REGULATOR_EVENT_UNDER_VOLTAGE_WARN	0x2000
+#define REGULATOR_EVENT_OVER_CURRENT_WARN	0x4000
+#define REGULATOR_EVENT_OVER_VOLTAGE_WARN	0x8000
+#define REGULATOR_EVENT_OVER_TEMP_WARN		0x10000
+#define REGULATOR_EVENT_WARN_MASK		0x1E000
 
 /*
  * Regulator errors that can be queried using regulator_get_error_flags
@@ -138,6 +148,10 @@ struct regulator_dev;
 #define REGULATOR_ERROR_FAIL			BIT(4)
 #define REGULATOR_ERROR_OVER_TEMP		BIT(5)
 
+#define REGULATOR_ERROR_UNDER_VOLTAGE_WARN	BIT(6)
+#define REGULATOR_ERROR_OVER_CURRENT_WARN	BIT(7)
+#define REGULATOR_ERROR_OVER_VOLTAGE_WARN	BIT(8)
+#define REGULATOR_ERROR_OVER_TEMP_WARN		BIT(9)
 
 /**
  * struct pre_voltage_change_data - Data sent with PRE_VOLTAGE_CHANGE event