Messages in this thread | | | Date | Mon, 21 Feb 2022 15:30:07 +0100 | From | AngeloGioacchino Del Regno <> | Subject | Re: [PATCH v8 04/19] video/hdmi: Add audio_infoframe packing for DP |
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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; > + 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 +486,44 @@ 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 > + * displayport
This fits in one line (82 cols is ok)... but, anyway, please capitalize D and P in the DisplayPort word.
> + * > + * @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.
> + * @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 header
Please, C-style comments:
/* Secondary-data packet header */
Thanks, Angelo
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