Re: [PATCH v6 2/3] 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 <redacted>
Signed-off-by: Joseph Hwang <redacted>

---

Changes in v6:
- Use the decimal version instead of hexadecimal version to be
 consistent with the AOSP specification.
- Move the code of checking the bluetooth_quality_report_support field
 to the previous patch.

Changes in v5:
- Fix the patch per
 [RFC PATCH] Bluetooth: Add framework for AOSP quality report setting
- Declare aosp_set_quality_report.
- Use aosp_do_open() to set hdev->aosp_set_quality_report.
- Add aosp_has_quality_report().
- In mgmt, use hdev->aosp_set_quality_report and
 hdev->set_quality_report separately.

Changes in v4:
- Move the AOSP BQR support from the driver level to net/bluetooth/aosp.
- Fix the drivers to use hci_set_aosp_capable to enable aosp.
- Add Mediatek to support the capability too.

Changes in v3:
- Fix the auto build test ERROR
 "undefined symbol: btandroid_set_quality_report" that occurred
 with some kernel configs.
- Note that the mgmt-tester "Read Exp Feature - Success" failed.
 But on my test device, the same test passed. Please kindly let me
 know what may be going wrong. These patches do not actually
 modify read/set experimental features.
- As to CheckPatch failed. No need to modify the MAINTAINERS file.
 Thanks.

Changes in v2:
- Fix the titles of patches 2/3 and 3/3 and reduce their lengths.

net/bluetooth/aosp.c | 87 ++++++++++++++++++++++++++++++++++++++++++++
net/bluetooth/aosp.h | 13 +++++++
net/bluetooth/mgmt.c | 18 ++++++---
3 files changed, 113 insertions(+), 5 deletions(-)

diff --git a/net/bluetooth/aosp.c b/net/bluetooth/aosp.c
index 64684b2bf79b..582c380a29fa 100644
--- a/net/bluetooth/aosp.c
+++ b/net/bluetooth/aosp.c

@@ -147,3 +147,90 @@ void aosp_do_close(struct hci_dev *hdev)

	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);
+}

diff --git a/net/bluetooth/aosp.h b/net/bluetooth/aosp.h
index 328fc6d39f70..2fd8886d51b2 100644
--- a/net/bluetooth/aosp.h
+++ b/net/bluetooth/aosp.h

@@ -8,9 +8,22 @@

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

diff --git a/net/bluetooth/mgmt.c b/net/bluetooth/mgmt.c
index 44683443300c..d6c322763567 100644
--- a/net/bluetooth/mgmt.c
+++ b/net/bluetooth/mgmt.c

@@ -39,6 +39,7 @@

#include "mgmt_config.h"
#include "msft.h"
#include "eir.h"
+#include "aosp.h"

#define MGMT_VERSION	1
#define MGMT_REVISION	21

@@ -3863,7 +3864,8 @@ static int read_exp_features_info(struct sock *sk, struct hci_dev *hdev,

		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

@@ -4127,7 +4129,8 @@ static int set_quality_report_func(struct sock *sk, struct hci_dev *hdev,

	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) {
+		BT_INFO("quality report not supported");

		err = mgmt_cmd_status(sk, hdev->id,
				      MGMT_OP_SET_EXP_FEATURE,
				      MGMT_STATUS_NOT_SUPPORTED);

@@ -4135,13 +4138,18 @@ static int set_quality_report_func(struct sock *sk, struct hci_dev *hdev,

	}

	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

@@ -4153,8 +4161,8 @@ static int set_quality_report_func(struct sock *sk, struct hci_dev *hdev,

	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));