Bluetooth: SCO: Add support for 16 bits transparent voice setting

JIRA: https://issues.redhat.com/browse/RHEL-74483

commit 29a6514
Author: Frédéric Danis <frederic.danis@collabora.com>
Date:   Thu Dec 5 16:51:59 2024 +0100

    Bluetooth: SCO: Add support for 16 bits transparent voice setting

    The voice setting is used by sco_connect() or sco_conn_defer_accept()
    after being set by sco_sock_setsockopt().

    The PCM part of the voice setting is used for offload mode through PCM
    chipset port.
    This commits add support for mSBC 16 bits offloading, i.e. audio data
    not transported over HCI.

    The BCM4349B1 supports 16 bits transparent data on its I2S port.
    If BT_VOICE_TRANSPARENT is used when accepting a SCO connection, this
    gives only garbage audio while using BT_VOICE_TRANSPARENT_16BIT gives
    correct audio.
    This has been tested with connection to iPhone 14 and Samsung S24.

    Fixes: ad10b1a ("Bluetooth: Add Bluetooth socket voice option")
    Signed-off-by: Frédéric Danis <frederic.danis@collabora.com>
    Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>

Signed-off-by: Bastien Nocera <bnocera@redhat.com>

Author: Bastien Nocera

include/net/bluetooth/bluetooth.h

@@ -123,6 +123,7 @@ struct bt_voice {
 
 #define BT_VOICE_TRANSPARENT			0x0003
 #define BT_VOICE_CVSD_16BIT			0x0060
+#define BT_VOICE_TRANSPARENT_16BIT		0x0063
 
 #define BT_SNDMTU		12
 #define BT_RCVMTU		13

net/bluetooth/sco.c

@@ -319,10 +319,13 @@ static int sco_connect(struct sock *sk)
 	else
 		type = SCO_LINK;
 
-	if (sco_pi(sk)->setting == BT_VOICE_TRANSPARENT &&
-	    (!lmp_transp_capable(hdev) || !lmp_esco_capable(hdev))) {
-		err = -EOPNOTSUPP;
-		goto unlock;
+	switch (sco_pi(sk)->setting & SCO_AIRMODE_MASK) {
+	case SCO_AIRMODE_TRANSP:
+		if (!lmp_transp_capable(hdev) || !lmp_esco_capable(hdev)) {
+			err = -EOPNOTSUPP;
+			goto unlock;
+		}
+		break;
 	}
 
 	hcon = hci_connect_sco(hdev, type, &sco_pi(sk)->dst,
@@ -920,23 +923,21 @@ static int sco_sock_setsockopt(struct socket *sock, int level, int optname,
 		if (err)
 			break;
 
-		/* Explicitly check for these values */
-		if (voice.setting != BT_VOICE_TRANSPARENT &&
-		    voice.setting != BT_VOICE_CVSD_16BIT) {
-			err = -EINVAL;
-			break;
-		}
-
 		sco_pi(sk)->setting = voice.setting;
 		hdev = hci_get_route(&sco_pi(sk)->dst, &sco_pi(sk)->src,
 				     BDADDR_BREDR);
 		if (!hdev) {
 			err = -EBADFD;
 			break;
 		}
-		if (enhanced_sync_conn_capable(hdev) &&
-		    voice.setting == BT_VOICE_TRANSPARENT)
-			sco_pi(sk)->codec.id = BT_CODEC_TRANSPARENT;
+
+		switch (sco_pi(sk)->setting & SCO_AIRMODE_MASK) {
+		case SCO_AIRMODE_TRANSP:
+			if (enhanced_sync_conn_capable(hdev))
+				sco_pi(sk)->codec.id = BT_CODEC_TRANSPARENT;
+			break;
+		}
+
 		hci_dev_put(hdev);
 		break;