Quoting AngeloGioacchino Del Regno (2022-02-21 15:30:07)
Il 18/02/22 15:54, Guillaume Ranquet ha scritto:
From: Markus Schneider-Pargmann msp@baylibre.com
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.
Signed-off-by: Markus Schneider-Pargmann msp@baylibre.com Signed-off-by: Guillaume Ranquet granquet@baylibre.com
drivers/video/hdmi.c | 83 ++++++++++++++++++++++++++++--------- include/drm/drm_dp_helper.h | 2 + include/linux/hdmi.h | 7 +++- 3 files changed, 72 insertions(+), 20 deletions(-)
diff --git a/drivers/video/hdmi.c b/drivers/video/hdmi.c index 947be761dfa40..63e74d9fd210e 100644 --- a/drivers/video/hdmi.c +++ b/drivers/video/hdmi.c @@ -21,6 +21,7 @@
- DEALINGS IN THE SOFTWARE.
*/
+#include <drm/drm_dp_helper.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;elsechannels = 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;elsechannels = 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 +486,44 @@ 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
displayportThis fits in one line (82 cols is ok)... but, anyway, please capitalize D and P in the DisplayPort word.
Yeah, I ran clang-format and didn't want to contradict the tool :) I'll fix that for v9
- @frame HDMI Audio infoframe
You're almost there! You missed a colon after each description. Also, I personally like seeing indented descriptions as, in my opinion, this enhances human readability, as it's a bit more pleasing to the eye... but it's not a requirement, so you be the judge.
- @frame: HDMI Audio infoframe
- @sdp: Secondary data packet......
- @dp_version: DisplayPort version......
Please fix.
I completly forgot to generate and check the kerneldoc. Sorry.
- @sdp secondary data packet for display port. This is filled with the
- appropriate data
- @dp_version Display Port version to be encoded in the header
- Packs a HDMI Audio Infoframe to be sent over Display Port. This function
- fills the secondary data packet to be used for Display Port.
- 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 headerPlease, C-style comments:
/* Secondary-data packet header */Thanks, Angelo
I think this is not the only case of C++ comment that slipped past me... I'll revise the whole series.
Thx, Guillaume.