media: cec: add support for Absolute Volume Control

Add support for this new CEC message. This was added in HDMI 2.1a.
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab@kernel.org>

Documentation/userspace-api/media/cec.h.rst.exceptions

@@ -239,6 +239,7 @@ ignore define CEC_OP_FEAT_DEV_HAS_DECK_CONTROL
 ignore define CEC_OP_FEAT_DEV_HAS_SET_AUDIO_RATE
 ignore define CEC_OP_FEAT_DEV_SINK_HAS_ARC_TX
 ignore define CEC_OP_FEAT_DEV_SOURCE_HAS_ARC_RX
+ignore define CEC_OP_FEAT_DEV_HAS_SET_AUDIO_VOLUME_LEVEL
 
 ignore define CEC_MSG_GIVE_FEATURES
 
@@ -487,6 +488,7 @@ ignore define CEC_OP_SYS_AUD_STATUS_ON
 
 ignore define CEC_MSG_SYSTEM_AUDIO_MODE_REQUEST
 ignore define CEC_MSG_SYSTEM_AUDIO_MODE_STATUS
+ignore define CEC_MSG_SET_AUDIO_VOLUME_LEVEL
 
 ignore define CEC_OP_AUD_FMT_ID_CEA861
 ignore define CEC_OP_AUD_FMT_ID_CEA861_CXT

drivers/media/cec/core/cec-adap.c

@@ -1027,6 +1027,7 @@ static const u8 cec_msg_size[256] = {
 	[CEC_MSG_REPORT_SHORT_AUDIO_DESCRIPTOR] = 2 | DIRECTED,
 	[CEC_MSG_REQUEST_SHORT_AUDIO_DESCRIPTOR] = 2 | DIRECTED,
 	[CEC_MSG_SET_SYSTEM_AUDIO_MODE] = 3 | BOTH,
+	[CEC_MSG_SET_AUDIO_VOLUME_LEVEL] = 3 | DIRECTED,
 	[CEC_MSG_SYSTEM_AUDIO_MODE_REQUEST] = 2 | DIRECTED,
 	[CEC_MSG_SYSTEM_AUDIO_MODE_STATUS] = 3 | DIRECTED,
 	[CEC_MSG_SET_AUDIO_RATE] = 3 | DIRECTED,

include/uapi/linux/cec-funcs.h

@@ -1568,6 +1568,20 @@ static inline void cec_ops_request_short_audio_descriptor(const struct cec_msg *
 	}
 }
 
+static inline void cec_msg_set_audio_volume_level(struct cec_msg *msg,
+						  __u8 audio_volume_level)
+{
+	msg->len = 3;
+	msg->msg[1] = CEC_MSG_SET_AUDIO_VOLUME_LEVEL;
+	msg->msg[2] = audio_volume_level;
+}
+
+static inline void cec_ops_set_audio_volume_level(const struct cec_msg *msg,
+						  __u8 *audio_volume_level)
+{
+	*audio_volume_level = msg->msg[2];
+}
+
 
 /* Audio Rate Control Feature */
 static inline void cec_msg_set_audio_rate(struct cec_msg *msg,

include/uapi/linux/cec.h

@@ -768,6 +768,7 @@ struct cec_event {
 #define CEC_OP_FEAT_DEV_HAS_SET_AUDIO_RATE		0x08
 #define CEC_OP_FEAT_DEV_SINK_HAS_ARC_TX			0x04
 #define CEC_OP_FEAT_DEV_SOURCE_HAS_ARC_RX		0x02
+#define CEC_OP_FEAT_DEV_HAS_SET_AUDIO_VOLUME_LEVEL	0x01
 
 #define CEC_MSG_GIVE_FEATURES				0xa5	/* HDMI 2.0 */
 
@@ -1059,6 +1060,7 @@ struct cec_event {
 #define CEC_OP_AUD_FMT_ID_CEA861			0
 #define CEC_OP_AUD_FMT_ID_CEA861_CXT			1
 
+#define CEC_MSG_SET_AUDIO_VOLUME_LEVEL			0x73
 
 /* Audio Rate Control Feature */
 #define CEC_MSG_SET_AUDIO_RATE				0x9a