video/hdmi: Introduce a generic hdmi_infoframe union

And a way to pack hdmi_infoframe generically.

Cc: Thierry Reding <thierry.reding@avionic-design.de>
Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: Damien Lespiau <damien.lespiau@intel.com>
Acked-by: Dave Airlie <airlied@gmail.com>
Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

2 files changed, 60 insertions, 0 deletions

diff --git a/drivers/video/hdmi.c b/drivers/video/hdmi.c
index dbd882ffafbb..f7a85e5b7370 100644
--- a/drivers/video/hdmi.c
+++ b/drivers/video/hdmi.c
@@ -22,6 +22,7 @@
  */
 
 #include <linux/bitops.h>
+#include <linux/bug.h>
 #include <linux/errno.h>
 #include <linux/export.h>
 #include <linux/hdmi.h>
@@ -321,3 +322,45 @@ ssize_t hdmi_vendor_infoframe_pack(struct hdmi_vendor_infoframe *frame,
         return length;
 }
 EXPORT_SYMBOL(hdmi_vendor_infoframe_pack);
+
+/**
+ * hdmi_infoframe_pack() - write a HDMI infoframe to binary buffer
+ * @frame: HDMI infoframe
+ * @buffer: destination buffer
+ * @size: size of buffer
+ *
+ * Packs the information contained in the @frame structure into a binary
+ * representation that can be written into the corresponding controller
+ * registers. 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_infoframe_pack(union hdmi_infoframe *frame, void *buffer, size_t size)
+{
+        ssize_t length;
+
+        switch (frame->any.type) {
+        case HDMI_INFOFRAME_TYPE_AVI:
+                length = hdmi_avi_infoframe_pack(&frame->avi, buffer, size);
+                break;
+        case HDMI_INFOFRAME_TYPE_SPD:
+                length = hdmi_spd_infoframe_pack(&frame->spd, buffer, size);
+                break;
+        case HDMI_INFOFRAME_TYPE_AUDIO:
+                length = hdmi_audio_infoframe_pack(&frame->audio, buffer, size);
+                break;
+        case HDMI_INFOFRAME_TYPE_VENDOR:
+                length = hdmi_vendor_infoframe_pack(&frame->vendor,
+                                                    buffer, size);
+                break;
+        default:
+                WARN(1, "Bad infoframe type %d\n", frame->any.type);
+                length = -EINVAL;
+        }
+
+        return length;
+}
+EXPORT_SYMBOL(hdmi_infoframe_pack);
diff --git a/include/linux/hdmi.h b/include/linux/hdmi.h
index 3b589440ecfe..0f3f82eadef7 100644
--- a/include/linux/hdmi.h
+++ b/include/linux/hdmi.h
@@ -23,6 +23,12 @@ enum hdmi_infoframe_type {
 #define HDMI_SPD_INFOFRAME_SIZE    25
 #define HDMI_AUDIO_INFOFRAME_SIZE  10
 
+struct hdmi_any_infoframe {
+        enum hdmi_infoframe_type type;
+        unsigned char version;
+        unsigned char length;
+};
+
 enum hdmi_colorspace {
         HDMI_COLORSPACE_RGB,
         HDMI_COLORSPACE_YUV422,
@@ -228,4 +234,15 @@ struct hdmi_vendor_infoframe {
 ssize_t hdmi_vendor_infoframe_pack(struct hdmi_vendor_infoframe *frame,
                                    void *buffer, size_t size);
 
+union hdmi_infoframe {
+        struct hdmi_any_infoframe any;
+        struct hdmi_avi_infoframe avi;
+        struct hdmi_spd_infoframe spd;
+        struct hdmi_vendor_infoframe vendor;
+        struct hdmi_audio_infoframe audio;
+};
+
+ssize_t
+hdmi_infoframe_pack(union hdmi_infoframe *frame, void *buffer, size_t size);
+
 #endif /* _DRM_HDMI_H */