[PATCH v3 1/3] Bluetooth: btandroid: Support Android Bluetooth Quality Report

[Joseph Hwang]

Add the btandroid.c file to support Android BQR commands.

This module may be referenced by btusb, btrtl, and hci_qca when a
Bluetooth controller supports the Android Bluetooth Quality Report.

Reported-by: kernel test robot <lkp@xxxxxxxxx>

Reviewed-by: Miao-chen Chou <mcchou@xxxxxxxxxxxx>
Signed-off-by: Joseph Hwang <josephsih@xxxxxxxxxxxx>
---

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.

 drivers/bluetooth/Kconfig     |   5 ++
 drivers/bluetooth/Makefile    |   1 +
 drivers/bluetooth/btandroid.c | 106 ++++++++++++++++++++++++++++++++++
 drivers/bluetooth/btandroid.h |  10 ++++
 4 files changed, 122 insertions(+)
 create mode 100644 drivers/bluetooth/btandroid.c
 create mode 100644 drivers/bluetooth/btandroid.h

diff --git a/drivers/bluetooth/Kconfig b/drivers/bluetooth/Kconfig
index 851842372c9b..0be352cdc6c9 100644
--- a/drivers/bluetooth/Kconfig
+++ b/drivers/bluetooth/Kconfig
@@ -19,10 +19,14 @@ config BT_QCA
 	tristate
 	select FW_LOADER
 
+config BT_HCIBTANDROID
+	tristate
+
 config BT_HCIBTUSB
 	tristate "HCI USB driver"
 	depends on USB
 	select BT_INTEL
+	select BT_HCIBTANDROID
 	help
 	  Bluetooth HCI USB driver.
 	  This driver is required if you want to use Bluetooth devices with
@@ -90,6 +94,7 @@ config BT_HCIUART
 	depends on SERIAL_DEV_BUS || !SERIAL_DEV_BUS
 	depends on NVMEM || !NVMEM
 	depends on TTY
+	select BT_HCIBTANDROID
 	help
 	  Bluetooth HCI UART driver.
 	  This driver is required if you want to use Bluetooth devices with
diff --git a/drivers/bluetooth/Makefile b/drivers/bluetooth/Makefile
index 16286ea2655d..3a2ca2eb7cd7 100644
--- a/drivers/bluetooth/Makefile
+++ b/drivers/bluetooth/Makefile
@@ -13,6 +13,7 @@ obj-$(CONFIG_BT_HCIBT3C)	+= bt3c_cs.o
 obj-$(CONFIG_BT_HCIBLUECARD)	+= bluecard_cs.o
 
 obj-$(CONFIG_BT_HCIBTUSB)	+= btusb.o
+obj-$(CONFIG_BT_HCIBTANDROID)	+= btandroid.o
 obj-$(CONFIG_BT_HCIBTSDIO)	+= btsdio.o
 
 obj-$(CONFIG_BT_INTEL)		+= btintel.o
diff --git a/drivers/bluetooth/btandroid.c b/drivers/bluetooth/btandroid.c
new file mode 100644
index 000000000000..fffacc8d67cc
--- /dev/null
+++ b/drivers/bluetooth/btandroid.c
@@ -0,0 +1,106 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ *  Support for Android Bluetooth Quality Report (BQR) specifications
+ *      https://source.android.com/devices/bluetooth/hci_requirements
+ *
+ *  Copyright (C) 2021 Google Corporation
+ */
+
+#include <linux/module.h>
+
+#include <net/bluetooth/bluetooth.h>
+#include <net/bluetooth/hci.h>
+
+#include "btandroid.h"
+
+#define VERSION "0.1"
+
+/*
+ * Reference for the command op codes and parameters below:
+ *   https://source.android.com/devices/bluetooth/hci_requirements#bluetooth-quality-report-command
+ */
+#define BQR_COMMAND_OCF			0x015e
+#define BQR_OPCODE			hci_opcode_pack(0x3f, BQR_COMMAND_OCF)
+
+/* report action */
+#define REPORT_ACTION_ADD		0x00
+#define REPORT_ACTION_DELETE		0x01
+#define REPORT_ACTION_CLEAR		0x02
+
+/* BQR event masks */
+#define QUALITY_MONITORING		(1 << 0)
+#define APPRAOCHING_LSTO		(1 << 1)
+#define A2DP_AUDIO_CHOPPY		(1 << 2)
+#define SCO_VOICE_CHOPPY		(1 << 3)
+
+#define DEFAULT_BQR_EVENT_MASK	(QUALITY_MONITORING | APPRAOCHING_LSTO | \
+				 A2DP_AUDIO_CHOPPY | SCO_VOICE_CHOPPY)
+
+/*
+ * Reporting at seconds so as not to stress the controller too much.
+ * Range: 0 ~ 65535 ms
+ */
+#define DEFALUT_REPORT_INTERVAL_MS	5000
+
+struct android_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 android_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 android_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;
+}
+
+int btandroid_set_quality_report(struct hci_dev *hdev, bool enable)
+{
+	bt_dev_info(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);
+}
+EXPORT_SYMBOL_GPL(btandroid_set_quality_report);
+
+MODULE_AUTHOR("Google");
+MODULE_DESCRIPTION("Support for Android Bluetooth Specification " VERSION);
+MODULE_VERSION(VERSION);
+MODULE_LICENSE("GPL");
diff --git a/drivers/bluetooth/btandroid.h b/drivers/bluetooth/btandroid.h
new file mode 100644
index 000000000000..6abc9e8e0838
--- /dev/null
+++ b/drivers/bluetooth/btandroid.h
@@ -0,0 +1,10 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/*
+ *  Bluetooth support for Android specifications
+ *
+ *  Copyright (C) 2021 Google Corporation
+ */
+
+#include <net/bluetooth/hci_core.h>
+
+int btandroid_set_quality_report(struct hci_dev *hdev, bool enable);
-- 
2.33.0.309.g3052b89438-goog