Bluetooth: aosp: Support AOSP Bluetooth Quality Report

This patch adds the support of the AOSP Bluetooth Quality Report
(BQR) events.

Multiple vendors have supported the AOSP Bluetooth Quality Report.
When a Bluetooth controller supports the capability, it can enable
the aosp capability through hci_set_aosp_capable. Then hci_core will
set up the hdev->aosp_set_quality_report callback through aosp_do_open
if the controller responds to support the quality report capability.

Note that Intel also supports a distinct telemetry quality report
specification. Intel sets up the hdev->set_quality_report callback
in the btusb driver module.

Reviewed-by: Miao-chen Chou <[e-mail]>
Signed-off-by: Joseph Hwang <[e-mail]>
Signed-off-by: Marcel Holtmann <[e-mail]>

net/bluetooth/aosp.c

···
 
 	bt_dev_dbg(hdev, "Cleanup of AOSP extension");
 }
+
+/* BQR command */
+#define BQR_OPCODE			hci_opcode_pack(0x3f, 0x015e)
+
+/* BQR report action */
+#define REPORT_ACTION_ADD		0x00
+#define REPORT_ACTION_DELETE		0x01
+#define REPORT_ACTION_CLEAR		0x02
+
+/* BQR event masks */
+#define QUALITY_MONITORING		BIT(0)
+#define APPRAOCHING_LSTO		BIT(1)
+#define A2DP_AUDIO_CHOPPY		BIT(2)
+#define SCO_VOICE_CHOPPY		BIT(3)
+
+#define DEFAULT_BQR_EVENT_MASK	(QUALITY_MONITORING | APPRAOCHING_LSTO | \
+				 A2DP_AUDIO_CHOPPY | SCO_VOICE_CHOPPY)
+
+/* Reporting at milliseconds so as not to stress the controller too much.
+ * Range: 0 ~ 65535 ms
+ */
+#define DEFALUT_REPORT_INTERVAL_MS	5000
+
+struct aosp_bqr_cp {
+	__u8	report_action;
+	__u32	event_mask;
+	__u16	min_report_interval;
+} __packed;
+
+static int enable_quality_report(struct hci_dev *hdev)
+{
+	struct sk_buff *skb;
+	struct aosp_bqr_cp cp;
+
+	cp.report_action = REPORT_ACTION_ADD;
+	cp.event_mask = DEFAULT_BQR_EVENT_MASK;
+	cp.min_report_interval = DEFALUT_REPORT_INTERVAL_MS;
+
+	skb = __hci_cmd_sync(hdev, BQR_OPCODE, sizeof(cp), &cp,
+			     HCI_CMD_TIMEOUT);
+	if (IS_ERR(skb)) {
+		bt_dev_err(hdev, "Enabling Android BQR failed (%ld)",
+			   PTR_ERR(skb));
+		return PTR_ERR(skb);
+	}
+
+	kfree_skb(skb);
+	return 0;
+}
+
+static int disable_quality_report(struct hci_dev *hdev)
+{
+	struct sk_buff *skb;
+	struct aosp_bqr_cp cp = { 0 };
+
+	cp.report_action = REPORT_ACTION_CLEAR;
+
+	skb = __hci_cmd_sync(hdev, BQR_OPCODE, sizeof(cp), &cp,
+			     HCI_CMD_TIMEOUT);
+	if (IS_ERR(skb)) {
+		bt_dev_err(hdev, "Disabling Android BQR failed (%ld)",
+			   PTR_ERR(skb));
+		return PTR_ERR(skb);
+	}
+
+	kfree_skb(skb);
+	return 0;
+}
+
+bool aosp_has_quality_report(struct hci_dev *hdev)
+{
+	return hdev->aosp_quality_report;
+}
+
+int aosp_set_quality_report(struct hci_dev *hdev, bool enable)
+{
+	if (!aosp_has_quality_report(hdev))
+		return -EOPNOTSUPP;
+
+	bt_dev_dbg(hdev, "quality report enable %d", enable);
+
+	/* Enable or disable the quality report feature. */
+	if (enable)
+		return enable_quality_report(hdev);
+	else
+		return disable_quality_report(hdev);
+}

net/bluetooth/aosp.h

···
 void aosp_do_open(struct hci_dev *hdev);
 void aosp_do_close(struct hci_dev *hdev);
 
+bool aosp_has_quality_report(struct hci_dev *hdev);
+int aosp_set_quality_report(struct hci_dev *hdev, bool enable);
+
 #else
 
 static inline void aosp_do_open(struct hci_dev *hdev) {}
 static inline void aosp_do_close(struct hci_dev *hdev) {}
+
+static inline bool aosp_has_quality_report(struct hci_dev *hdev)
+{
+	return false;
+}
+
+static inline int aosp_set_quality_report(struct hci_dev *hdev, bool enable)
+{
+	return -EOPNOTSUPP;
+}
 
 #endif

net/bluetooth/mgmt.c

···
 #include "mgmt_config.h"
 #include "msft.h"
 #include "eir.h"
+#include "aosp.h"
 
 #define MGMT_VERSION	1
 #define MGMT_REVISION	21
···
 		idx++;
 	}
 
-	if (hdev && hdev->set_quality_report) {
+	if (hdev && (aosp_has_quality_report(hdev) ||
+		     hdev->set_quality_report)) {
 		if (hci_dev_test_flag(hdev, HCI_QUALITY_REPORT))
 			flags = BIT(0);
 		else
···
 	val = !!cp->param[0];
 	changed = (val != hci_dev_test_flag(hdev, HCI_QUALITY_REPORT));
 
-	if (!hdev->set_quality_report) {
+	if (!aosp_has_quality_report(hdev) && !hdev->set_quality_report) {
 		err = mgmt_cmd_status(sk, hdev->id,
 				      MGMT_OP_SET_EXP_FEATURE,
 				      MGMT_STATUS_NOT_SUPPORTED);
···
 	}
 
 	if (changed) {
-		err = hdev->set_quality_report(hdev, val);
+		if (hdev->set_quality_report)
+			err = hdev->set_quality_report(hdev, val);
+		else
+			err = aosp_set_quality_report(hdev, val);
+
 		if (err) {
 			err = mgmt_cmd_status(sk, hdev->id,
 					      MGMT_OP_SET_EXP_FEATURE,
 					      MGMT_STATUS_FAILED);
 			goto unlock_quality_report;
 		}
+
 		if (val)
 			hci_dev_set_flag(hdev, HCI_QUALITY_REPORT);
 		else
···
 	memcpy(rp.uuid, quality_report_uuid, 16);
 	rp.flags = cpu_to_le32(val ? BIT(0) : 0);
 	hci_sock_set_flag(sk, HCI_MGMT_EXP_FEATURE_EVENTS);
-	err = mgmt_cmd_complete(sk, hdev->id,
-				MGMT_OP_SET_EXP_FEATURE, 0,
+
+	err = mgmt_cmd_complete(sk, hdev->id, MGMT_OP_SET_EXP_FEATURE, 0,
 				&rp, sizeof(rp));
 
 	if (changed)