* [PATCH v3] Bluetooth: btintel: Add Bluetooth SAR revision 2 support
@ 2026-07-22 15:59 Kiran K
2026-07-22 17:06 ` [v3] " bluez.test.bot
0 siblings, 1 reply; 2+ messages in thread
From: Kiran K @ 2026-07-22 15:59 UTC (permalink / raw)
To: linux-bluetooth
Cc: ravishankar.srivatsa, chethan.tumkur.narayan,
chandrashekar.devegowda, Kiran K, Ravindra
BRDS revision 2 introduces per-chain (Chain A and Chain B) TX power
limits across five sub-bands (2.4G, 5.2G, 5.8/5.9G, 6G-low, 6G-high),
replacing the single-chain per-modulation model of revisions 0 and 1.
- Add btintel_set_sar_rev2() which sends the full Rev2 DDC sequence:
0x019e inc-power-mode enable flag (1 byte)
0x0311 2.4 GHz sub-band limits (2 bytes)
0x0312 5.2 GHz sub-band limits (2 bytes)
0x0313 5.8/5.9 GHz sub-band limits (2 bytes)
0x0314 5.8/5.9 GHz sub-band limits again (2 bytes, duplicate FW reg)
0x0315 6 GHz low sub-band limits (2 bytes)
0x0316 6 GHz high sub-band limits (2 bytes)
followed by the SAR-init-complete command (0xfe25).
logs from dmesg when BTSAR2 is enabled in Coreboot/BIOS:
Bluetooth: hci0: BT SAR Rev2: revision=2 bt_sar_bios=1 inc_power_mode=1
Bluetooth: hci0: BT SAR Rev2 Chain A: 2g4=76 5g2=0 5g8_5g9=0 6g1=0 6g3=0
Bluetooth: hci0: BT SAR Rev2 Chain B: 2g4=102 5g2=0 5g8_5g9=0 6g1=0 6g3=0
Signed-off-by: Ravindra <ravindra@intel.com>
Signed-off-by: Kiran K <kiran.k@intel.com>
---
changes in v3:
- Fix comment in the code.
- Address comments from Luiz.
changes in v2:
changes in v2:
- Update commit message to include logs.
- Validate the ACPI types/size before accessing.
drivers/bluetooth/btintel.c | 191 +++++++++++++++++++++++++++++++++++-
drivers/bluetooth/btintel.h | 18 ++++
2 files changed, 208 insertions(+), 1 deletion(-)
diff --git a/drivers/bluetooth/btintel.c b/drivers/bluetooth/btintel.c
index 5e9cac090bd8..2f1b78ddb9a7 100644
--- a/drivers/bluetooth/btintel.c
+++ b/drivers/bluetooth/btintel.c
@@ -51,6 +51,7 @@ enum {
#define BTINTEL_BT_DOMAIN 0x12
#define BTINTEL_SAR_LEGACY 0
#define BTINTEL_SAR_INC_PWR 1
+#define BTINTEL_SAR_REV2 2
#define BTINTEL_SAR_INC_PWR_SUPPORTED 0
#define CMD_WRITE_BOOT_PARAMS 0xfc0e
@@ -3104,6 +3105,111 @@ static int btintel_set_mutual_sar(struct hci_dev *hdev, struct btintel_sar_inc_p
return 0;
}
+/* btintel_send_sar_rev2_band - send DDC command for one Rev2 sub-band
+ *
+ * Each DDC 0x0311-0x0316 carries 2 bytes: [ChainA_value, ChainB_value].
+ * cmd->len = 4 (2 id + 2 data)
+ * HCI total = 5 bytes (1 len + 4)
+ */
+static int btintel_send_sar_rev2_band(struct hci_dev *hdev,
+ struct btintel_cp_ddc_write *cmd,
+ u16 id, u8 chain_a, u8 chain_b)
+{
+ cmd->len = 4;
+ cmd->id = cpu_to_le16(id);
+ cmd->data[0] = chain_a;
+ cmd->data[1] = chain_b;
+ return btintel_send_sar_ddc(hdev, cmd, 5);
+}
+
+static int btintel_set_sar_rev2(struct hci_dev *hdev,
+ struct btintel_sar_rev2 *sar)
+{
+ struct btintel_cp_ddc_write *cmd;
+ struct sk_buff *skb;
+ u8 buffer[64];
+ u8 enable;
+ int ret;
+
+ cmd = (void *)buffer;
+
+ /* DDC 0x019e: enable/disable increased power mode SAR (1 byte) */
+ cmd->len = 3;
+ cmd->id = cpu_to_le16(0x019e);
+ cmd->data[0] = (sar->inc_power_mode == BTINTEL_SAR_INC_PWR_SUPPORTED) ?
+ 0x01 : 0x00;
+ ret = btintel_send_sar_ddc(hdev, cmd, 4);
+ if (ret)
+ return ret;
+
+ /* DDC 0x0311-0x0316: per sub-band ChainA + ChainB limits */
+ ret = btintel_send_sar_rev2_band(hdev, cmd, 0x0311,
+ sar->chain_a.subband_2g4,
+ sar->chain_b.subband_2g4);
+ if (ret)
+ return ret;
+
+ ret = btintel_send_sar_rev2_band(hdev, cmd, 0x0312,
+ sar->chain_a.subband_5g2,
+ sar->chain_b.subband_5g2);
+ if (ret)
+ return ret;
+
+ /* 0x0313 and 0x0314 both carry the 5G8/5G9 value */
+ ret = btintel_send_sar_rev2_band(hdev, cmd, 0x0313,
+ sar->chain_a.subband_5g8_5g9,
+ sar->chain_b.subband_5g8_5g9);
+ if (ret)
+ return ret;
+
+ ret = btintel_send_sar_rev2_band(hdev, cmd, 0x0314,
+ sar->chain_a.subband_5g8_5g9,
+ sar->chain_b.subband_5g8_5g9);
+ if (ret)
+ return ret;
+
+ ret = btintel_send_sar_rev2_band(hdev, cmd, 0x0315,
+ sar->chain_a.subband_6g1,
+ sar->chain_b.subband_6g1);
+ if (ret)
+ return ret;
+
+ ret = btintel_send_sar_rev2_band(hdev, cmd, 0x0316,
+ sar->chain_a.subband_6g3,
+ sar->chain_b.subband_6g3);
+ if (ret)
+ return ret;
+
+ /* Notify firmware that SAR initialisation is complete */
+ enable = 0x01;
+ skb = __hci_cmd_sync(hdev, 0xfe25, sizeof(enable), &enable, HCI_CMD_TIMEOUT);
+ if (IS_ERR(skb)) {
+ bt_dev_warn(hdev, "Failed to send Intel SAR Rev2 Enable (%ld)",
+ PTR_ERR(skb));
+ return PTR_ERR(skb);
+ }
+
+ kfree_skb(skb);
+ return 0;
+}
+
+static int btintel_sar_rev2_send_to_device(struct hci_dev *hdev,
+ struct btintel_sar_rev2 *sar,
+ struct intel_version_tlv *ver)
+{
+ u16 cnvi = ver->cnvi_top & 0xfff;
+ u16 cnvr = ver->cnvr_top & 0xfff;
+
+ if (cnvi < BTINTEL_CNVI_BLAZARI || cnvr != BTINTEL_CNVR_WHP2) {
+ bt_dev_dbg(hdev, "BT SAR Rev2 not supported on this platform (cnvi=0x%x cnvr=0x%x)",
+ cnvi, cnvr);
+ return -EOPNOTSUPP;
+ }
+
+ bt_dev_info(hdev, "Applying Bluetooth SAR Rev2");
+ return btintel_set_sar_rev2(hdev, sar);
+}
+
static int btintel_sar_send_to_device(struct hci_dev *hdev, struct btintel_sar_inc_pwr *sar,
struct intel_version_tlv *ver)
{
@@ -3130,6 +3236,7 @@ static int btintel_acpi_set_sar(struct hci_dev *hdev, struct intel_version_tlv *
{
union acpi_object *bt_pkg, *buffer = NULL;
struct btintel_sar_inc_pwr sar;
+ struct btintel_sar_rev2 sar_rev2;
acpi_status status;
u8 revision;
int ret;
@@ -3150,14 +3257,96 @@ static int btintel_acpi_set_sar(struct hci_dev *hdev, struct intel_version_tlv *
goto error;
}
+ if (buffer->package.elements[0].type != ACPI_TYPE_INTEGER) {
+ bt_dev_warn(hdev, "BT_SAR: unexpected ACPI type for revision field");
+ ret = -EINVAL;
+ goto error;
+ }
+
revision = buffer->package.elements[0].integer.value;
- if (revision > BTINTEL_SAR_INC_PWR) {
+ if (revision > BTINTEL_SAR_REV2) {
bt_dev_dbg(hdev, "BT_SAR: revision: 0x%2.2x not supported", revision);
ret = -EOPNOTSUPP;
goto error;
}
+ if (revision == BTINTEL_SAR_REV2 && bt_pkg->package.count == 13) {
+ /* Element layout: 0 = domain ID (BTINTEL_BT_DOMAIN, 0x12),
+ * 1 = bt_sar_bios (u32), 2 = inc_power_mode (u32),
+ * 3..12 = per-chain sub-band limits (u8 each).
+ */
+ static const u64 rev2_max[13] = {
+ U8_MAX, /* domain ID */
+ U32_MAX, U32_MAX, /* bt_sar_bios, inc_power_mode */
+ U8_MAX, U8_MAX, U8_MAX, U8_MAX, U8_MAX, /* chain A */
+ U8_MAX, U8_MAX, U8_MAX, U8_MAX, U8_MAX, /* chain B */
+ };
+ union acpi_object *e;
+ int i;
+
+ for (i = 0; i < 13; i++) {
+ e = &bt_pkg->package.elements[i];
+ if (e->type != ACPI_TYPE_INTEGER) {
+ bt_dev_warn(hdev, "BT SAR Rev2: unexpected ACPI type at element %d",
+ i);
+ ret = -EINVAL;
+ goto error;
+ }
+ if (e->integer.value > rev2_max[i]) {
+ bt_dev_warn(hdev, "BT SAR Rev2: element %d value 0x%llx out of range",
+ i, e->integer.value);
+ ret = -ERANGE;
+ goto error;
+ }
+ }
+
+ memset(&sar_rev2, 0, sizeof(sar_rev2));
+ sar_rev2.revision = revision;
+
+ if (sar_rev2.bt_sar_bios != 1) {
+ bt_dev_warn(hdev, "Bluetooth SAR Rev2 is not enabled");
+ ret = -EOPNOTSUPP;
+ goto error;
+ }
+
+ sar_rev2.bt_sar_bios = bt_pkg->package.elements[1].integer.value;
+ sar_rev2.inc_power_mode = bt_pkg->package.elements[2].integer.value;
+
+ sar_rev2.chain_a.subband_2g4 = bt_pkg->package.elements[3].integer.value;
+ sar_rev2.chain_a.subband_5g2 = bt_pkg->package.elements[4].integer.value;
+ sar_rev2.chain_a.subband_5g8_5g9 = bt_pkg->package.elements[5].integer.value;
+ sar_rev2.chain_a.subband_6g1 = bt_pkg->package.elements[6].integer.value;
+ sar_rev2.chain_a.subband_6g3 = bt_pkg->package.elements[7].integer.value;
+
+ sar_rev2.chain_b.subband_2g4 = bt_pkg->package.elements[8].integer.value;
+ sar_rev2.chain_b.subband_5g2 = bt_pkg->package.elements[9].integer.value;
+ sar_rev2.chain_b.subband_5g8_5g9 = bt_pkg->package.elements[10].integer.value;
+ sar_rev2.chain_b.subband_6g1 = bt_pkg->package.elements[11].integer.value;
+ sar_rev2.chain_b.subband_6g3 = bt_pkg->package.elements[12].integer.value;
+
+ bt_dev_dbg(hdev, "BT SAR Rev2: revision=%u bt_sar_bios=%u inc_power_mode=%u",
+ sar_rev2.revision, sar_rev2.bt_sar_bios, sar_rev2.inc_power_mode);
+ bt_dev_dbg(hdev, "BT SAR Rev2 Chain A: 2g4=%u 5g2=%u 5g8_5g9=%u 6g1=%u 6g3=%u",
+ sar_rev2.chain_a.subband_2g4, sar_rev2.chain_a.subband_5g2,
+ sar_rev2.chain_a.subband_5g8_5g9, sar_rev2.chain_a.subband_6g1,
+ sar_rev2.chain_a.subband_6g3);
+ bt_dev_dbg(hdev, "BT SAR Rev2 Chain B: 2g4=%u 5g2=%u 5g8_5g9=%u 6g1=%u 6g3=%u",
+ sar_rev2.chain_b.subband_2g4, sar_rev2.chain_b.subband_5g2,
+ sar_rev2.chain_b.subband_5g8_5g9, sar_rev2.chain_b.subband_6g1,
+ sar_rev2.chain_b.subband_6g3);
+
+ ret = btintel_sar_rev2_send_to_device(hdev, &sar_rev2, ver);
+ goto error;
+ }
+
+ if (revision == BTINTEL_SAR_REV2) {
+ bt_dev_warn(hdev, "BT SAR Rev2: unexpected ACPI package count %d (expected 13)",
+ bt_pkg->package.count);
+ ret = -EINVAL;
+ goto error;
+ }
+
memset(&sar, 0, sizeof(sar));
if (revision == BTINTEL_SAR_LEGACY && bt_pkg->package.count == 8) {
diff --git a/drivers/bluetooth/btintel.h b/drivers/bluetooth/btintel.h
index 37d93abdd5a3..966ec1b02be2 100644
--- a/drivers/bluetooth/btintel.h
+++ b/drivers/bluetooth/btintel.h
@@ -65,6 +65,7 @@ struct intel_tlv {
/* CNVR */
#define BTINTEL_CNVR_FMP2 0x910
+#define BTINTEL_CNVR_WHP2 0xA10 /* Whale Peak2 - Panther Lake */
#define BTINTEL_IMG_BOOTLOADER 0x01 /* Bootloader image */
#define BTINTEL_IMG_IML 0x02 /* Intermediate image */
@@ -204,6 +205,23 @@ struct btintel_sar_inc_pwr {
u8 le_lr;
};
+/* Bluetooth SAR feature (BRDS), Revision 2 - per-chain sub-band power limits */
+struct btintel_sar_band_limits {
+ u8 subband_2g4;
+ u8 subband_5g2;
+ u8 subband_5g8_5g9;
+ u8 subband_6g1;
+ u8 subband_6g3;
+};
+
+struct btintel_sar_rev2 {
+ u8 revision;
+ u32 bt_sar_bios; /* 1: BIOS-managed SAR enabled */
+ u32 inc_power_mode; /* 0: supported, 1: disabled */
+ struct btintel_sar_band_limits chain_a;
+ struct btintel_sar_band_limits chain_b;
+};
+
#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)
--
2.54.0
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2026-07-22 15:59 [PATCH v3] Bluetooth: btintel: Add Bluetooth SAR revision 2 support Kiran K
2026-07-22 17:06 ` [v3] " bluez.test.bot
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