mkbp: add support for board-specific host notification

On Nocturne, we want to be able to decide whether MKBP events should be
notified to the AP via host_set_single_event or gpio_set_level based
upon runtime board-version detection instead of a static compile-time flag.

Add support for this by marking the function that raises the actual IRQ
to the host as weak, so that individual boards can override it with their
own version.

BRANCH=None
BUG=b:112366846, b:112112483, b:112111610
TEST=see CL:1161546 for details

Signed-off-by: Enrico Granata <egranata@chromium.org>
Change-Id: Ide5ec12fbc6fea3cf23069f376066f225e1887b3
Reviewed-on: https://chromium-review.googlesource.com/1247000
Reviewed-by: Alexandru M Stan <amstan@chromium.org>
Reviewed-by: Gwendal Grignou <gwendal@chromium.org>

1 files changed, 23 insertions, 7 deletions

diff --git a/common/mkbp_event.c b/common/mkbp_event.c
index 40a6e21066..08e88f287e 100644
--- a/common/mkbp_event.c
+++ b/common/mkbp_event.c
@@ -33,6 +33,28 @@ static int event_is_set(uint8_t event_type)
 	return events & (1 << event_type);
 }
 
+#ifndef CONFIG_MKBP_USE_HOST_EVENT
+void send_mkbp_event_gpio(int active)
+{
+	gpio_set_level(GPIO_EC_INT_L, !active);
+}
+#endif
+
+void send_mkbp_event_host(int active)
+{
+	if (active)
+		host_set_single_event(EC_HOST_EVENT_MKBP);
+}
+
+__attribute__((weak)) void send_mkbp_event(int active)
+{
+#ifdef CONFIG_MKBP_USE_HOST_EVENT
+	send_mkbp_event_host(active);
+#else
+	send_mkbp_event_gpio(active);
+#endif
+}
+
 /**
  * Assert host keyboard interrupt line.
  */
@@ -45,13 +67,7 @@ static void set_host_interrupt(int active)
 	if (old_active == 0 && active == 1)
 		mkbp_last_event_time = __hw_clock_source_read();
 
-	/* interrupt host by using active low EC_INT signal */
-#ifdef CONFIG_MKBP_USE_HOST_EVENT
-	if (active)
-		host_set_single_event(EC_HOST_EVENT_MKBP);
-#else
-	gpio_set_level(GPIO_EC_INT_L, !active);
-#endif
+	send_mkbp_event(active);
 
 	old_active = active;
 	interrupt_enable();