drivers/wifi: Support Extended Bluetooth Regulatory Descriptor

Extended Bluetooth Regulatory Descriptor (EBRD) SAR/RFE are safety
regulations for limiting antenna radiation near human contact. EBRD
provides option to provide up to three sets of TX power limits and
power restrictions.

As the EBRD table is related to the revision 2 of the BRDS, this
commit also adds support for this new revision.

The implementation follows document 559910 Intel Connectivity
Platforms BIOS Guideline revision 9.2 specification.

BUG=b:346600091
TEST=EBRD method is added to the bluetooth companion device and
     return the data supplied by the SAR binary blob

Change-Id: Iebe95815c944d045f4cf686abcd1874a8a45e250
Signed-off-by: Jeremy Compostella <jeremy.compostella@intel.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/84947
Reviewed-by: Subrata Banik <subratabanik@google.com>
Reviewed-by: Kapil Porwal <kapilporwal@google.com>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>

1 files changed, 57 insertions, 5 deletions

diff --git a/src/drivers/wifi/generic/acpi.c b/src/drivers/wifi/generic/acpi.c
index 3cd55e36fe..be44f6b907 100644
--- a/src/drivers/wifi/generic/acpi.c
+++ b/src/drivers/wifi/generic/acpi.c
@@ -599,7 +599,7 @@ static void sar_emit_brds(const struct bsar_profile *bsar)
 	 *   }
 	 * })
 	 */
-	if (bsar->revision != BSAR_REVISION) {
+	if (bsar->revision == 0 || bsar->revision > MAX_BSAR_REVISION) {
 		printk(BIOS_ERR, "Unsupported BSAR table revision: %d\n",
 		       bsar->revision);
 		return;
@@ -609,11 +609,14 @@ static void sar_emit_brds(const struct bsar_profile *bsar)
 	acpigen_write_package(2);
 	acpigen_write_dword(bsar->revision);
 
-	table_size = sizeof(*bsar) -
-		offsetof(struct bsar_profile, sar_lb_power_restriction);
+	if (bsar->revision == 1)
+		table_size = sizeof(bsar->revs.rev1);
+	else
+		table_size = sizeof(bsar->revs.rev2);
+
 	/*
 	 * Emit 'Domain Type' + 'Dynamic SAR Enable' + 'Increase Power Mode'
-	 * + ('SAR Power Restriction' + SAR table).
+	 * + ('SAR Power Restriction' + SAR table) | (Chain A and B SAR tables).
 	 */
 	package_size = 1 + 1 + 1 + table_size;
 	acpigen_write_package(package_size);
@@ -621,7 +624,7 @@ static void sar_emit_brds(const struct bsar_profile *bsar)
 	acpigen_write_dword(1);
 	acpigen_write_dword(bsar->increased_power_mode_limitation);
 
-	set = (const uint8_t *)&bsar->sar_lb_power_restriction;
+	set = (const uint8_t *)&bsar->revs;
 	for (int i = 0; i < table_size; i++)
 		acpigen_write_byte(set[i]);
 
@@ -876,6 +879,54 @@ static void sar_emit_bdmm(const struct bdmm_profile *bdmm)
 	acpigen_write_package_end();
 }
 
+static void sar_emit_ebrd(const struct ebrd_profile *ebrd)
+{
+	if (ebrd == NULL)
+		return;
+
+	size_t package_size, table_size;
+	const uint8_t *set;
+
+	/*
+	 * Name ("EBRD", Package () {
+	 *   Revision,
+	 *   Package () {
+	 *     Domain Type,			// 0x12:Bluetooth
+	 *     Dynamic SAR Enable,
+	 *     Number of Optional SAR,
+	 *     Three SAR Sets
+	 *   }
+	 * })
+	 */
+	if (ebrd->revision != EBRD_REVISION) {
+		printk(BIOS_ERR, "Unsupported EBRD table revision: %d\n",
+		       ebrd->revision);
+		return;
+	}
+
+	acpigen_write_name("EBRD");
+	acpigen_write_package(2);
+	acpigen_write_dword(ebrd->revision);
+
+	/*
+	 * Emit 'Domain Type' + 'Dynamic Sar Enabled' + 'Number of Optional SAR' +
+	 * 'Three SAR Sets'
+	 */
+	table_size = sizeof(*ebrd) - offsetof(struct ebrd_profile, sar_table_sets);
+	package_size = 1 + 1 + 1 + table_size;
+	acpigen_write_package(package_size);
+	acpigen_write_dword(DOMAIN_TYPE_BLUETOOTH);
+	acpigen_write_dword(ebrd->dynamic_sar_enable);
+	acpigen_write_dword(ebrd->number_of_optional_sar);
+
+	set = (const uint8_t *)&ebrd->sar_table_sets;
+	for (size_t i = 0; i < table_size; i++)
+		acpigen_write_byte(set[i]);
+
+	acpigen_write_package_end();
+	acpigen_write_package_end();
+}
+
 static void emit_wifi_sar_acpi_structures(const struct device *dev,
 					  union wifi_sar_limits *sar_limits)
 {
@@ -1014,6 +1065,7 @@ static void wifi_ssdt_write_properties(const struct device *dev, const char *sco
 			sar_emit_bbsm(sar_limits.bbsm);
 			sar_emit_bucs(sar_limits.bucs);
 			sar_emit_bdmm(sar_limits.bdmm);
+			sar_emit_ebrd(sar_limits.ebrd);
 			acpigen_write_scope_end();
 		} else {
 			printk(BIOS_ERR, "Failed to get %s Bluetooth companion ACPI path\n",