[PATCH 11/12] drm: Add a helper to forge HDMI vendor infoframes

[Damien Lespiau]

This can then be used by DRM drivers to setup their vendor infoframes.

Signed-off-by: Damien Lespiau <damien.lespiau at intel.com>
---
 drivers/gpu/drm/drm_edid.c | 36 ++++++++++++++++++++++++++++++++++++
 include/drm/drm_edid.h     |  4 ++++
 2 files changed, 40 insertions(+)

diff --git a/drivers/gpu/drm/drm_edid.c b/drivers/gpu/drm/drm_edid.c
index 9a07a33..83e1202 100644
--- a/drivers/gpu/drm/drm_edid.c
+++ b/drivers/gpu/drm/drm_edid.c
@@ -3262,3 +3262,39 @@ drm_hdmi_avi_infoframe_from_display_mode(struct hdmi_avi_infoframe *frame,
 	return 0;
 }
 EXPORT_SYMBOL(drm_hdmi_avi_infoframe_from_display_mode);
+
+/**
+ * drm_hdmi_vendor_infoframe_from_display_mode() - fill an HDMI infoframe with
+ * data from a DRM display mode
+ * @frame: HDMI vendor infoframe
+ * @mode: DRM display mode
+ *
+ * Note that there's is a need to send HDMI vendor infoframes only when using a
+ * 4k or stereoscopic 3D mode. So when giving any other mode as input this
+ * function will return -EINVAL, error that can be safely ignored.
+ *
+ * Returns 0 on success or a negative error code on failure.
+ */
+int
+drm_hdmi_vendor_infoframe_from_display_mode(struct hdmi_hdmi_infoframe *frame,
+					    const struct drm_display_mode *mode)
+{
+	int err;
+	u8 vic;
+
+	if (!frame || !mode)
+		return -EINVAL;
+
+	vic = drm_match_hmdi_mode(mode);
+	if (!vic)
+		return -EINVAL;
+
+	err = hdmi_hdmi_infoframe_init(frame);
+	if (err < 0)
+		return err;
+
+	frame->vic = vic;
+
+	return 0;
+}
+EXPORT_SYMBOL(drm_hdmi_vendor_infoframe_from_display_mode);
diff --git a/include/drm/drm_edid.h b/include/drm/drm_edid.h
index fc481fc..a204e31 100644
--- a/include/drm/drm_edid.h
+++ b/include/drm/drm_edid.h
@@ -256,6 +256,7 @@ struct drm_encoder;
 struct drm_connector;
 struct drm_display_mode;
 struct hdmi_avi_infoframe;
+struct hdmi_hdmi_infoframe;
 
 void drm_edid_to_eld(struct drm_connector *connector, struct edid *edid);
 int drm_edid_to_sad(struct edid *edid, struct cea_sad **sads);
@@ -268,5 +269,8 @@ int drm_load_edid_firmware(struct drm_connector *connector);
 int
 drm_hdmi_avi_infoframe_from_display_mode(struct hdmi_avi_infoframe *frame,
 					 const struct drm_display_mode *mode);
+int
+drm_hdmi_vendor_infoframe_from_display_mode(struct hdmi_hdmi_infoframe *frame,
+					    const struct drm_display_mode *mode);
 
 #endif /* __DRM_EDID_H__ */
-- 
1.8.3.1