@@ -240,6 +240,49 @@ int hdmi_audio_infoframe_init(struct hdmi_audio_infoframe *frame)
EXPORT_SYMBOL(hdmi_audio_infoframe_init);
/**
+ * hdmi_audio_infoframe_pack_payload() - write HDMI audio infoframe payload to
+ * binary buffer
+ * @frame: HDMI audio 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.
+ *
+ * Returns 0 on success or a negative error code on failure.
+ */
+ssize_t hdmi_audio_infoframe_pack_payload(struct hdmi_audio_infoframe *frame,
+ void *buffer, size_t size)
+{
+ unsigned char channels;
+ u8 *ptr = buffer;
+
+ if (size < frame->length || size < HDMI_AUDIO_INFOFRAME_SIZE)
+ return -ENOSPC;
+
+ memset(buffer, 0, size);
+
+ if (frame->channels >= 2)
+ channels = frame->channels - 1;
+ else
+ channels = 0;
+
+ ptr[0] = ((frame->coding_type & 0xf) << 4) | (channels & 0x7);
+ ptr[1] = ((frame->sample_frequency & 0x7) << 2) |
+ (frame->sample_size & 0x3);
+ ptr[2] = frame->coding_type_ext & 0x1f;
+ ptr[3] = frame->channel_allocation;
+ ptr[4] = (frame->level_shift_value & 0xf) << 3;
+
+ if (frame->downmix_inhibit)
+ ptr[4] |= BIT(7);
+
+ return 0;
+}
+EXPORT_SYMBOL(hdmi_audio_infoframe_pack_payload);
+
+/**
* hdmi_audio_infoframe_pack() - write HDMI audio infoframe to binary buffer
* @frame: HDMI audio infoframe
* @buffer: destination buffer
@@ -256,22 +299,15 @@ EXPORT_SYMBOL(hdmi_audio_infoframe_init);
ssize_t hdmi_audio_infoframe_pack(struct hdmi_audio_infoframe *frame,
void *buffer, size_t size)
{
- unsigned char channels;
u8 *ptr = buffer;
size_t length;
+ int ret;
length = HDMI_INFOFRAME_HEADER_SIZE + frame->length;
if (size < length)
return -ENOSPC;
- memset(buffer, 0, size);
-
- if (frame->channels >= 2)
- channels = frame->channels - 1;
- else
- channels = 0;
-
ptr[0] = frame->type;
ptr[1] = frame->version;
ptr[2] = frame->length;
@@ -279,16 +315,10 @@ ssize_t hdmi_audio_infoframe_pack(struct hdmi_audio_infoframe *frame,
/* start infoframe payload */
ptr += HDMI_INFOFRAME_HEADER_SIZE;
-
- ptr[0] = ((frame->coding_type & 0xf) << 4) | (channels & 0x7);
- ptr[1] = ((frame->sample_frequency & 0x7) << 2) |
- (frame->sample_size & 0x3);
- ptr[2] = frame->coding_type_ext & 0x1f;
- ptr[3] = frame->channel_allocation;
- ptr[4] = (frame->level_shift_value & 0xf) << 3;
-
- if (frame->downmix_inhibit)
- ptr[4] |= BIT(7);
+ ret = hdmi_audio_infoframe_pack_payload(frame, ptr,
+ size - HDMI_INFOFRAME_HEADER_SIZE);
+ if (ret)
+ return ret;
hdmi_infoframe_set_checksum(buffer, length);
@@ -272,6 +272,8 @@ struct hdmi_audio_infoframe {
int hdmi_audio_infoframe_init(struct hdmi_audio_infoframe *frame);
ssize_t hdmi_audio_infoframe_pack(struct hdmi_audio_infoframe *frame,
void *buffer, size_t size);
+ssize_t hdmi_audio_infoframe_pack_payload(struct hdmi_audio_infoframe *frame,
+ void *buffer, size_t size);
enum hdmi_3d_structure {
HDMI_3D_STRUCTURE_INVALID = -1,
The DP is using the same audio infoframe payload as hdmi, per DP 1.3 spec, but it has a different header. Provide a new interface here, it just packs the payload. Signed-off-by: Chris Zhong <zyw@rock-chips.com> --- Changes in v3: - add size < HDMI_AUDIO_INFOFRAME_SIZE check according to Doug's advice Changes in v2: None drivers/video/hdmi.c | 66 ++++++++++++++++++++++++++++++++++++++-------------- include/linux/hdmi.h | 2 ++ 2 files changed, 50 insertions(+), 18 deletions(-)