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video/hdmi: Add audio_infoframe packing for DP 

Similar to HDMI, DP uses audio infoframes as well which are structured
very similar to the HDMI ones.

This patch adds a helper function to pack the HDMI audio infoframe for
DP, called hdmi_audio_infoframe_pack_for_dp().
hdmi_audio_infoframe_pack_only() is split into two parts. One of them
packs the payload only and can be used for HDMI and DP.

Also constify the frame parameter in hdmi_audio_infoframe_check() as
it is passed to hdmi_audio_infoframe_check_only() which expects a const.

Signed-off-by: Markus Schneider-Pargmann <msp@baylibre.com>
Signed-off-by: Guillaume Ranquet <granquet@baylibre.com>
Signed-off-by: Bo-Chen Chen <rex-bc.chen@mediatek.com>
Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Signed-off-by: Dmitry Osipenko <dmitry.osipenko@collabora.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20220901044149.16782-3-rex-bc.chen@mediatek.com
This commit is contained in:
Markus Schneider-Pargmann 2022-09-01 12:41:41 +08:00 committed by Dmitry Osipenko
parent a2ce58e8f9
commit f89aa0b6db
3 changed files with 71 additions and 20 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

82
drivers/video/hdmi.c
View File

@ -21,6 +21,7 @@
* DEALINGS IN THE SOFTWARE.
*/
#include <drm/display/drm_dp.h>
#include <linux/bitops.h>
#include <linux/bug.h>
#include <linux/errno.h>
@ -381,12 +382,34 @@ static int hdmi_audio_infoframe_check_only(const struct hdmi_audio_infoframe *fr
*
* Returns 0 on success or a negative error code on failure.
*/
int hdmi_audio_infoframe_check(struct hdmi_audio_infoframe *frame)
int hdmi_audio_infoframe_check(const struct hdmi_audio_infoframe *frame)
{
return hdmi_audio_infoframe_check_only(frame);
}
EXPORT_SYMBOL(hdmi_audio_infoframe_check);
static void
hdmi_audio_infoframe_pack_payload(const struct hdmi_audio_infoframe *frame,
u8 *buffer)
{
u8 channels;
if (frame->channels >= 2)
channels = frame->channels - 1;
else
channels = 0;
buffer[0] = ((frame->coding_type & 0xf) << 4) | (channels & 0x7);
buffer[1] = ((frame->sample_frequency & 0x7) << 2) |
(frame->sample_size & 0x3);
buffer[2] = frame->coding_type_ext & 0x1f;
buffer[3] = frame->channel_allocation;
buffer[4] = (frame->level_shift_value & 0xf) << 3;
if (frame->downmix_inhibit)
buffer[4] |= BIT(7);
}
/**
* hdmi_audio_infoframe_pack_only() - write HDMI audio infoframe to binary buffer
* @frame: HDMI audio infoframe
@ -404,7 +427,6 @@ EXPORT_SYMBOL(hdmi_audio_infoframe_check);
ssize_t hdmi_audio_infoframe_pack_only(const struct hdmi_audio_infoframe *frame,
void *buffer, size_t size)
{
unsigned char channels;
u8 *ptr = buffer;
size_t length;
int ret;
@ -420,28 +442,13 @@ ssize_t hdmi_audio_infoframe_pack_only(const struct hdmi_audio_infoframe *frame,
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;
ptr[3] = 0; /* checksum */
/* 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);
hdmi_audio_infoframe_pack_payload(frame,
ptr + HDMI_INFOFRAME_HEADER_SIZE);
hdmi_infoframe_set_checksum(buffer, length);
@ -479,6 +486,43 @@ ssize_t hdmi_audio_infoframe_pack(struct hdmi_audio_infoframe *frame,
}
EXPORT_SYMBOL(hdmi_audio_infoframe_pack);
/**
* hdmi_audio_infoframe_pack_for_dp - Pack a HDMI Audio infoframe for DisplayPort
*
* @frame: HDMI Audio infoframe
* @sdp: Secondary data packet for DisplayPort.
* @dp_version: DisplayPort version to be encoded in the header
*
* Packs a HDMI Audio Infoframe to be sent over DisplayPort. This function
* fills the secondary data packet to be used for DisplayPort.
*
* Return: Number of total written bytes or a negative errno on failure.
*/
ssize_t
hdmi_audio_infoframe_pack_for_dp(const struct hdmi_audio_infoframe *frame,
struct dp_sdp *sdp, u8 dp_version)
{
int ret;
ret = hdmi_audio_infoframe_check(frame);
if (ret)
return ret;
memset(sdp->db, 0, sizeof(sdp->db));
/* Secondary-data packet header */
sdp->sdp_header.HB0 = 0;
sdp->sdp_header.HB1 = frame->type;
sdp->sdp_header.HB2 = DP_SDP_AUDIO_INFOFRAME_HB2;
sdp->sdp_header.HB3 = (dp_version & 0x3f) << 2;
hdmi_audio_infoframe_pack_payload(frame, sdp->db);
/* Return size = frame length + four HB for sdp_header */
return frame->length + 4;
}
EXPORT_SYMBOL(hdmi_audio_infoframe_pack_for_dp);
/**
* hdmi_vendor_infoframe_init() - initialize an HDMI vendor infoframe
* @frame: HDMI vendor infoframe

2
include/drm/display/drm_dp.h
View File

@ -1536,6 +1536,8 @@ enum drm_dp_phy {
#define DP_SDP_VSC_EXT_CEA 0x21 /* DP 1.4 */
/* 0x80+ CEA-861 infoframe types */
#define DP_SDP_AUDIO_INFOFRAME_HB2 0x1b
/**
* struct dp_sdp_header - DP secondary data packet header
* @HB0: Secondary Data Packet ID

7
include/linux/hdmi.h
View File

@ -336,7 +336,12 @@ ssize_t hdmi_audio_infoframe_pack(struct hdmi_audio_infoframe *frame,
void *buffer, size_t size);
ssize_t hdmi_audio_infoframe_pack_only(const struct hdmi_audio_infoframe *frame,
void *buffer, size_t size);
int hdmi_audio_infoframe_check(struct hdmi_audio_infoframe *frame);
int hdmi_audio_infoframe_check(const struct hdmi_audio_infoframe *frame);
struct dp_sdp;
ssize_t
hdmi_audio_infoframe_pack_for_dp(const struct hdmi_audio_infoframe *frame,
struct dp_sdp *sdp, u8 dp_version);
enum hdmi_3d_structure {
HDMI_3D_STRUCTURE_INVALID = -1,