[v5 13/13] video/hdmi: Add const variants for drm infoframe

[Uma Shankar]

Added the const version of infoframe for DRM metadata
for HDR.

Signed-off-by: Uma Shankar <uma.shankar at intel.com>
---
 drivers/video/hdmi.c | 63 ++++++++++++++++++++++++++++++++++++++++++++++++++--
 include/linux/hdmi.h |  5 +++++
 2 files changed, 66 insertions(+), 2 deletions(-)

diff --git a/drivers/video/hdmi.c b/drivers/video/hdmi.c
index 7ab8086..b1b21ae 100644
--- a/drivers/video/hdmi.c
+++ b/drivers/video/hdmi.c
@@ -668,6 +668,30 @@ int hdmi_drm_infoframe_init(struct hdmi_drm_infoframe *frame)
 }
 EXPORT_SYMBOL(hdmi_drm_infoframe_init);
 
+static int hdmi_drm_infoframe_check_only(const struct hdmi_drm_infoframe *frame)
+{
+	if (frame->type != HDMI_INFOFRAME_TYPE_DRM ||
+	    frame->version != 1)
+		return -EINVAL;
+
+	return 0;
+}
+
+/**
+ * hdmi_drm_infoframe_check() - check a HDMI DRM infoframe
+ * @frame: HDMI DRM infoframe
+ *
+ * Validates that the infoframe is consistent and updates derived fields
+ * (eg. length) based on other fields.
+ *
+ * Returns 0 on success or a negative error code on failure.
+ */
+int hdmi_drm_infoframe_check(struct hdmi_drm_infoframe *frame)
+{
+	return hdmi_drm_infoframe_check_only(frame);
+}
+EXPORT_SYMBOL(hdmi_drm_infoframe_check);
+
 /**
  * hdmi_drm_infoframe_pack() - write HDMI DRM infoframe to binary buffer
  * @frame: HDMI DRM infoframe
@@ -682,8 +706,8 @@ int hdmi_drm_infoframe_init(struct hdmi_drm_infoframe *frame)
  * Returns the number of bytes packed into the binary buffer or a negative
  * error code on failure.
  */
-ssize_t hdmi_drm_infoframe_pack(struct hdmi_drm_infoframe *frame, void *buffer,
-				size_t size)
+ssize_t hdmi_drm_infoframe_pack_only(const struct hdmi_drm_infoframe *frame,
+				     void *buffer, size_t size)
 {
 	u8 *ptr = buffer;
 	size_t length;
@@ -736,6 +760,37 @@ ssize_t hdmi_drm_infoframe_pack(struct hdmi_drm_infoframe *frame, void *buffer,
 
 	return length;
 }
+EXPORT_SYMBOL(hdmi_drm_infoframe_pack_only);
+
+/**
+ * hdmi_drm_infoframe_pack() - check a HDMI DRM infoframe,
+ *                             and write it to binary buffer
+ * @frame: HDMI DRM infoframe
+ * @buffer: destination buffer
+ * @size: size of buffer
+ *
+ * Validates that the infoframe is consistent and updates derived fields
+ * (eg. length) based on other fields, after which it packs the information
+ * contained in the @frame structure into a binary representation that
+ * can be written into the corresponding controller registers. This function
+ * also computes the checksum as required by section 5.3.5 of the HDMI 1.4
+ * specification.
+ *
+ * Returns the number of bytes packed into the binary buffer or a negative
+ * error code on failure.
+ */
+ssize_t hdmi_drm_infoframe_pack(struct hdmi_drm_infoframe *frame,
+				void *buffer, size_t size)
+{
+	int ret;
+
+	ret = hdmi_drm_infoframe_check(frame);
+	if (ret)
+		return ret;
+
+	return hdmi_drm_infoframe_pack_only(frame, buffer, size);
+}
+EXPORT_SYMBOL(hdmi_drm_infoframe_pack);
 
 /*
  * hdmi_vendor_any_infoframe_check() - check a vendor infoframe
@@ -845,6 +900,10 @@ ssize_t hdmi_drm_infoframe_pack(struct hdmi_drm_infoframe *frame, void *buffer,
 		length = hdmi_avi_infoframe_pack_only(&frame->avi,
 						      buffer, size);
 		break;
+	case HDMI_INFOFRAME_TYPE_DRM:
+		length = hdmi_drm_infoframe_pack_only(&frame->drm,
+						      buffer, size);
+		break;
 	case HDMI_INFOFRAME_TYPE_SPD:
 		length = hdmi_spd_infoframe_pack_only(&frame->spd,
 						      buffer, size);
diff --git a/include/linux/hdmi.h b/include/linux/hdmi.h
index ad652e6..fbeb06e3 100644
--- a/include/linux/hdmi.h
+++ b/include/linux/hdmi.h
@@ -213,6 +213,11 @@ ssize_t hdmi_avi_infoframe_pack_only(const struct hdmi_avi_infoframe *frame,
 				     void *buffer, size_t size);
 int hdmi_avi_infoframe_check(struct hdmi_avi_infoframe *frame);
 int hdmi_drm_infoframe_init(struct hdmi_drm_infoframe *frame);
+ssize_t hdmi_drm_infoframe_pack(struct hdmi_drm_infoframe *frame, void *buffer,
+				size_t size);
+ssize_t hdmi_drm_infoframe_pack_only(const struct hdmi_drm_infoframe *frame,
+				     void *buffer, size_t size);
+int hdmi_drm_infoframe_check(struct hdmi_drm_infoframe *frame);
 
 enum hdmi_spd_sdi {
 	HDMI_SPD_SDI_UNKNOWN,
-- 
1.9.1