diff mbox series

[v9,06/22] video/hdmi: Add audio_infoframe packing for DP

Message ID 20220327223927.20848-7-granquet@baylibre.com (mailing list archive)
State New, archived
Headers show
Series drm/mediatek: Add mt8195 DisplayPort driver | expand

Commit Message

Guillaume Ranquet March 27, 2022, 10:39 p.m. UTC
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           | 82 ++++++++++++++++++++++++++--------
 include/drm/dp/drm_dp_helper.h |  2 +
 include/linux/hdmi.h           |  7 ++-
 3 files changed, 71 insertions(+), 20 deletions(-)

Comments

AngeloGioacchino Del Regno March 28, 2022, 8:09 a.m. UTC | #1
Il 28/03/22 00:39, 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           | 82 ++++++++++++++++++++++++++--------
>   include/drm/dp/drm_dp_helper.h |  2 +
>   include/linux/hdmi.h           |  7 ++-
>   3 files changed, 71 insertions(+), 20 deletions(-)
> 
> diff --git a/drivers/video/hdmi.c b/drivers/video/hdmi.c
> index 947be761dfa4..5f50237554ed 100644
> --- a/drivers/video/hdmi.c
> +++ b/drivers/video/hdmi.c
> @@ -21,6 +21,7 @@
>    * DEALINGS IN THE SOFTWARE.
>    */
>   
> +#include <drm/dp/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)

I agree with this change, as hdmi_audio_infoframe_check_only()'s param is a const,
but you really should mention that you're constifying this one in your commit
description, or do that in a separate commit.

Either of the two is fine.

Regards,
Angelo
Guillaume Ranquet April 12, 2022, 8:59 a.m. UTC | #2
On Mon, 28 Mar 2022 10:09, AngeloGioacchino Del Regno
<angelogioacchino.delregno@collabora.com> wrote:
>Il 28/03/22 00:39, 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           | 82 ++++++++++++++++++++++++++--------
>>   include/drm/dp/drm_dp_helper.h |  2 +
>>   include/linux/hdmi.h           |  7 ++-
>>   3 files changed, 71 insertions(+), 20 deletions(-)
>>
>> diff --git a/drivers/video/hdmi.c b/drivers/video/hdmi.c
>> index 947be761dfa4..5f50237554ed 100644
>> --- a/drivers/video/hdmi.c
>> +++ b/drivers/video/hdmi.c
>> @@ -21,6 +21,7 @@
>>    * DEALINGS IN THE SOFTWARE.
>>    */
>>
>> +#include <drm/dp/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)
>
>I agree with this change, as hdmi_audio_infoframe_check_only()'s param is a const,
>but you really should mention that you're constifying this one in your commit
>description, or do that in a separate commit.
>
>Either of the two is fine.
>
>Regards,
>Angelo

Noted, I'll add it to the commit message.

Thx,
Guillaume.
diff mbox series

Patch

diff --git a/drivers/video/hdmi.c b/drivers/video/hdmi.c
index 947be761dfa4..5f50237554ed 100644
--- a/drivers/video/hdmi.c
+++ b/drivers/video/hdmi.c
@@ -21,6 +21,7 @@ 
  * DEALINGS IN THE SOFTWARE.
  */
 
+#include <drm/dp/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 +486,43 @@  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 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/dp/drm_dp_helper.h b/include/drm/dp/drm_dp_helper.h
index 51e02cf75277..d4adb479263e 100644
--- a/include/drm/dp/drm_dp_helper.h
+++ b/include/drm/dp/drm_dp_helper.h
@@ -1576,6 +1576,8 @@  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,