Bluetooth: btintel: Set Per Platform Antenna Gain(PPAG)

Antenna gain is defined as the antenna’s ability to
increase the Tx power in a given direction. Intel
is certifying its products with fixed reference
antenna peak gain values (3/5dBi). The feature takes
into account the actual antenna gain, and increases
output power values, which results in a performance
improvement.

After firmware download is completed, driver reads from
ACPI table and configures PPAG as required. ACPI table
entry for PPAG is defined as below.

Name (PPAG, Package (0x02)
{
    0x00000001,
    Package (0x02)
    {
        0x00000012, /* Bluetooth Domain */
        0x00000001  /* 1 - Enable PPAG, 0 - Disable PPAG */
    }
})

btmon log:
< HCI Command: Intel Configure Per Platform Antenna Gain (0x3f|0x0219) plen 12
        Mcc: 0x00000000
        Selector: Enable
        Delta: 0x00000000
> HCI Event: Command Complete (0x0e) plen 4
      Intel Configure Per Platform Antenna Gain (0x3f|0x0219) ncmd 1
        Status: Success (0x00)

Signed-off-by: Kiran K <kiran.k@intel.com>
Signed-off-by: Seema Sreemantha <seema.sreemantha@intel.com>
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>

drivers/bluetooth/btintel.c

@@ -9,6 +9,7 @@
 #include <linux/module.h>
 #include <linux/firmware.h>
 #include <linux/regmap.h>
+#include <linux/acpi.h>
 #include <asm/unaligned.h>
 
 #include <net/bluetooth/bluetooth.h>
@@ -24,6 +25,9 @@
 #define ECDSA_OFFSET		644
 #define ECDSA_HEADER_LEN	320
 
+#define BTINTEL_PPAG_NAME   "PPAG"
+#define BTINTEL_PPAG_PREFIX "\\_SB_.PCI0.XHCI.RHUB"
+
 #define CMD_WRITE_BOOT_PARAMS	0xfc0e
 struct cmd_write_boot_params {
 	__le32 boot_addr;
@@ -1278,6 +1282,63 @@ static int btintel_read_debug_features(struct hci_dev *hdev,
 	return 0;
 }
 
+static acpi_status btintel_ppag_callback(acpi_handle handle, u32 lvl, void *data,
+					 void **ret)
+{
+	acpi_status status;
+	size_t len;
+	struct btintel_ppag *ppag = data;
+	union acpi_object *p, *elements;
+	struct acpi_buffer string = {ACPI_ALLOCATE_BUFFER, NULL};
+	struct acpi_buffer buffer = {ACPI_ALLOCATE_BUFFER, NULL};
+	struct hci_dev *hdev = ppag->hdev;
+
+	status = acpi_get_name(handle, ACPI_FULL_PATHNAME, &string);
+	if (ACPI_FAILURE(status)) {
+		bt_dev_warn(hdev, "ACPI Failure: %s", acpi_format_exception(status));
+		return status;
+	}
+
+	if (strncmp(BTINTEL_PPAG_PREFIX, string.pointer,
+		    strlen(BTINTEL_PPAG_PREFIX))) {
+		kfree(string.pointer);
+		return AE_OK;
+	}
+
+	len = strlen(string.pointer);
+	if (strncmp((char *)string.pointer + len - 4, BTINTEL_PPAG_NAME, 4)) {
+		kfree(string.pointer);
+		return AE_OK;
+	}
+	kfree(string.pointer);
+
+	status = acpi_evaluate_object(handle, NULL, NULL, &buffer);
+	if (ACPI_FAILURE(status)) {
+		bt_dev_warn(hdev, "ACPI Failure: %s", acpi_format_exception(status));
+		return status;
+	}
+
+	p = buffer.pointer;
+	ppag = (struct btintel_ppag *)data;
+
+	if (p->type != ACPI_TYPE_PACKAGE || p->package.count != 2) {
+		kfree(buffer.pointer);
+		bt_dev_warn(hdev, "Invalid object type: %d or package count: %d",
+			    p->type, p->package.count);
+		return AE_ERROR;
+	}
+
+	elements = p->package.elements;
+
+	/* PPAG table is located at element[1] */
+	p = &elements[1];
+
+	ppag->domain = (u32)p->package.elements[0].integer.value;
+	ppag->mode = (u32)p->package.elements[1].integer.value;
+	kfree(buffer.pointer);
+	return AE_CTRL_TERMINATE;
+}
+
 static int btintel_set_debug_features(struct hci_dev *hdev,
 			       const struct intel_debug_features *features)
 {
@@ -2251,6 +2312,58 @@ static int btintel_configure_offload(struct hci_dev *hdev)
 	return err;
 }
 
+static void btintel_set_ppag(struct hci_dev *hdev, struct intel_version_tlv *ver)
+{
+	acpi_status status;
+	struct btintel_ppag ppag;
+	struct sk_buff *skb;
+	struct btintel_loc_aware_reg ppag_cmd;
+
+    /* PPAG is not supported if CRF is HrP2, Jfp2, JfP1 */
+	switch (ver->cnvr_top & 0xFFF) {
+	case 0x504:     /* Hrp2 */
+	case 0x202:     /* Jfp2 */
+	case 0x201:     /* Jfp1 */
+		return;
+	}
+
+	memset(&ppag, 0, sizeof(ppag));
+
+	ppag.hdev = hdev;
+	status = acpi_walk_namespace(ACPI_TYPE_ANY, ACPI_ROOT_OBJECT,
+				     ACPI_UINT32_MAX, NULL,
+				     btintel_ppag_callback, &ppag, NULL);
+
+	if (ACPI_FAILURE(status)) {
+		/* Do not log warning message if ACPI entry is not found */
+		if (status == AE_NOT_FOUND)
+			return;
+		bt_dev_warn(hdev, "PPAG: ACPI Failure: %s", acpi_format_exception(status));
+		return;
+	}
+
+	if (ppag.domain != 0x12) {
+		bt_dev_warn(hdev, "PPAG-BT Domain disabled");
+		return;
+	}
+
+	/* PPAG mode, BIT0 = 0 Disabled, BIT0 = 1 Enabled */
+	if (!(ppag.mode & BIT(0))) {
+		bt_dev_dbg(hdev, "PPAG disabled");
+		return;
+	}
+
+	ppag_cmd.mcc = cpu_to_le32(0);
+	ppag_cmd.sel = cpu_to_le32(0); /* 0 - Enable , 1 - Disable, 2 - Testing mode */
+	ppag_cmd.delta = cpu_to_le32(0);
+	skb = __hci_cmd_sync(hdev, 0xfe19, sizeof(ppag_cmd), &ppag_cmd, HCI_CMD_TIMEOUT);
+	if (IS_ERR(skb)) {
+		bt_dev_warn(hdev, "Failed to send PPAG Enable (%ld)", PTR_ERR(skb));
+		return;
+	}
+	kfree_skb(skb);
+}
+
 static int btintel_bootloader_setup_tlv(struct hci_dev *hdev,
 					struct intel_version_tlv *ver)
 {
@@ -2297,6 +2410,9 @@ static int btintel_bootloader_setup_tlv(struct hci_dev *hdev,
 
 	hci_dev_clear_flag(hdev, HCI_QUALITY_REPORT);
 
+	/* Set PPAG feature */
+	btintel_set_ppag(hdev, ver);
+
 	/* Read the Intel version information after loading the FW  */
 	err = btintel_read_version_tlv(hdev, &new_ver);
 	if (err)

drivers/bluetooth/btintel.h

@@ -137,6 +137,19 @@ struct intel_offload_use_cases {
 	__u8	preset[8];
 } __packed;
 
+/* structure to store the PPAG data read from ACPI table */
+struct btintel_ppag {
+	u32	domain;
+	u32     mode;
+	struct hci_dev *hdev;
+};
+
+struct btintel_loc_aware_reg {
+	__le32 mcc;
+	__le32 sel;
+	__le32 delta;
+} __packed;
+
 #define INTEL_HW_PLATFORM(cnvx_bt)	((u8)(((cnvx_bt) & 0x0000ff00) >> 8))
 #define INTEL_HW_VARIANT(cnvx_bt)	((u8)(((cnvx_bt) & 0x003f0000) >> 16))
 #define INTEL_CNVX_TOP_TYPE(cnvx_top)	((cnvx_top) & 0x00000fff)