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 ---
Notes: Changes v1 -> v2: - Create a define for HB2. - Use struct dp_sdp to pass data in a better way.
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 947be761dfa4..63e74d9fd210 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 + * + * @frame HDMI Audio infoframe + * @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 + 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 frame->length + 4; +} +EXPORT_SYMBOL(hdmi_audio_infoframe_pack_for_dp); + /** * hdmi_vendor_infoframe_init() - initialize an HDMI vendor infoframe * @frame: HDMI vendor infoframe diff --git a/include/drm/drm_dp_helper.h b/include/drm/drm_dp_helper.h index 1d5b3dbb6e56..9debbcc34b14 100644 --- a/include/drm/drm_dp_helper.h +++ b/include/drm/drm_dp_helper.h @@ -1524,6 +1524,8 @@ int drm_dp_bw_code_to_link_rate(u8 link_bw); #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 diff --git a/include/linux/hdmi.h b/include/linux/hdmi.h index c8ec982ff498..2f4dcc8d060e 100644 --- a/include/linux/hdmi.h +++ b/include/linux/hdmi.h @@ -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,