[PATCH v8 4/7] mfd: cros_ec: Add cros_ec_get_host_event

[Tomeu Vizoso <tomeu.vizoso@collabora.com>]

This function returns the code for the host event that triggered the
interrupt that is being currently handled.

Is to be used by observers of the event_notifier in the EC device.

Signed-off-by: Tomeu Vizoso <tomeu.vizoso@collabora.com>
---

Changes in v8:
- Remove unnecessary variable host_event

Changes in v7: None
Changes in v6:
- Return 0 if the EC doesn't support MKBP, as expected by callers.

Changes in v5: None
Changes in v4: None
Changes in v3: None
Changes in v2: None

 drivers/platform/chrome/cros_ec_proto.c | 20 ++++++++++++++++++++
 include/linux/mfd/cros_ec.h             |  9 +++++++++
 2 files changed, 29 insertions(+)

diff --git a/drivers/platform/chrome/cros_ec_proto.c b/drivers/platform/chrome/cros_ec_proto.c
index f9677747cb3e..da4188eecea4 100644
--- a/drivers/platform/chrome/cros_ec_proto.c
+++ b/drivers/platform/chrome/cros_ec_proto.c
@@ -487,3 +487,23 @@ int cros_ec_cmd_xfer_status(struct cros_ec_device *ec_dev,
 	return ret;
 }
 EXPORT_SYMBOL(cros_ec_cmd_xfer_status);
+
+u32 cros_ec_get_host_event(struct cros_ec_device *ec_dev)
+{
+	if (!ec_dev->mkbp_event_supported) {
+		dev_warn(ec_dev->dev,
+			 "This EC does not support EC_MKBP_EVENT_HOST_EVENT");
+		return 0;
+	}
+
+	if (ec_dev->event_data.event_type != EC_MKBP_EVENT_HOST_EVENT)
+		return 0;
+
+	if (ec_dev->event_size != sizeof(ec_dev->event_data.data.host_event)) {
+		dev_warn(ec_dev->dev, "Invalid host event size\n");
+		return 0;
+	}
+
+	return get_unaligned_le32(&ec_dev->event_data.data.host_event);
+}
+EXPORT_SYMBOL(cros_ec_get_host_event);
diff --git a/include/linux/mfd/cros_ec.h b/include/linux/mfd/cros_ec.h
index 5d965aff5065..a39ed030d34f 100644
--- a/include/linux/mfd/cros_ec.h
+++ b/include/linux/mfd/cros_ec.h
@@ -288,6 +288,15 @@ int cros_ec_query_all(struct cros_ec_device *ec_dev);
  */
 int cros_ec_get_next_event(struct cros_ec_device *ec_dev);
 
+/**
+ * cros_ec_get_host_event - Return a mask of event set by the EC.
+ *
+ * @ec_dev: Device to fetch event from
+ *
+ * Returns: event mask of the event that caused the last interrupt to be raised
+ */
+uint32_t cros_ec_get_host_event(struct cros_ec_device *ec_dev);
+
 /* sysfs stuff */
 extern struct attribute_group cros_ec_attr_group;
 extern struct attribute_group cros_ec_lightbar_attr_group;
-- 
2.5.5