power: Add flags parameter to power_signal_info

Replace structure member "level" in power_signal_info with "flags".
"level" has been used on all boards to indicate active-high or
active-low levels. Addition of "flags" allows easy extension of
power_signal_info structure to define various flags that might be
applicable to power signals (e.g. "level"). Going forward, additional
flag will be added in follow-up CLs.

Also, provide a helper function power_signal_is_asserted that checks
the actual level of a signal and compares it to the flags level to
identify if a power signal is asserted.

BUG=b:65421825
BRANCH=None
TEST=make -j buildall

Change-Id: Iacaabd1185b347c17b5159f05520731505b824b8
Signed-off-by: Furquan Shaikh <furquan@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/679979
Reviewed-by: Nicolas Boichat <drinkcat@chromium.org>

1 files changed, 26 insertions, 1 deletions

diff --git a/include/power.h b/include/power.h
index cdfcbcd173..9e0c29bd1b 100644
--- a/include/power.h
+++ b/include/power.h
@@ -36,10 +36,26 @@ enum power_state {
 #endif
 };
 
+/*
+ * Power signal flags:
+ *
+ * +-----------------+------------------------------------+
+ * |     Bit #       |           Description              |
+ * +------------------------------------------------------+
+ * |       0         |      Active level (low/high)       |
+ * +------------------------------------------------------+
+ * |     1 : 32      |            Reserved                |
+ * +-----------------+------------------------------------+
+ */
+
+#define POWER_SIGNAL_ACTIVE_STATE	(1 << 0)
+#define POWER_SIGNAL_ACTIVE_LOW	(0 << 0)
+#define POWER_SIGNAL_ACTIVE_HIGH	(1 << 0)
+
 /* Information on an power signal */
 struct power_signal_info {
 	enum gpio_signal gpio;	/* GPIO for signal */
-	int level;		/* GPIO level which sets signal bit */
+	uint32_t flags;		/* See POWER_SIGNAL_* macros */
 	const char *name;	/* Name of signal */
 };
 
@@ -58,6 +74,15 @@ extern const struct power_signal_info power_signal_list[];
 uint32_t power_get_signals(void);
 
 /**
+ * Check if provided power signal is currently asserted.
+ *
+ * @param s		Power signal that needs to be checked.
+ *
+ * @return 1 if power signal is asserted, 0 otherwise.
+ */
+int power_signal_is_asserted(const struct power_signal_info *s);
+
+/**
  * Check for required inputs
  *
  * @param want		Mask of signals which must be present (one or more