drivers/wifi: Support Bluetooth Regulator Domain Settings

The 'Bluetooth Increased Power Mode - SAR Limitation' feature provides
ability to utilize increased device Transmit power capability for
Bluetooth applications in coordination with Wi-Fi adhering to product
SAR limit when Bluetooth and Wi-Fi run together.

This commit introduces a `bluetooth_companion' field to the generic
Wi-Fi drivers chip data. This field can be set in the board design
device tree to supply the bluetooth device for which the BRDS function
must be created.

This feature is required for Meteor Lake rex karis variant.

The implementation follows document 559910 Intel Connectivity
Platforms BIOS Guideline revision 8.3 specification.

BUG=b:348345301
BRANCH=firmware-rex-15709.B
TEST=BRDS method is added to the CNVW device and return the data
     supplied by the SAR binary blob

Change-Id: Iebe95815c944d045f4cf686abcd1874a8a45e209
Signed-off-by: Jeremy Compostella <jeremy.compostella@intel.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/83200
Reviewed-by: Eric Lai <ericllai@google.com>
Reviewed-by: Subrata Banik <subratabanik@google.com>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>

2 files changed, 80 insertions, 4 deletions

diff --git a/src/drivers/wifi/generic/acpi.c b/src/drivers/wifi/generic/acpi.c
index d3da51b116..e303589660 100644
--- a/src/drivers/wifi/generic/acpi.c
+++ b/src/drivers/wifi/generic/acpi.c
@@ -15,8 +15,9 @@
 #include "wifi.h"
 #include "wifi_private.h"
 
-/* WIFI Domain type */
+/* Domain type */
 #define DOMAIN_TYPE_WIFI 0x7
+#define DOMAIN_TYPE_BLUETOOTH 0x12
 
 /* Maximum number DSM UUID bifurcations in _DSM */
 #define MAX_DSM_FUNCS 2
@@ -489,9 +490,59 @@ static void sar_emit_wtas(struct avg_profile *wtas)
 	acpigen_write_package_end();
 }
 
-static void emit_sar_acpi_structures(const struct device *dev, struct dsm_profile *dsm)
+static void sar_emit_brds(const struct bsar_profile *bsar)
 {
-	union wifi_sar_limits sar_limits = {{NULL, NULL, NULL, NULL, NULL} };
+	size_t package_size, table_size;
+	const uint8_t *set;
+
+	/*
+	 * Name ("BRDS", Package () {
+	 *   Revision,
+	 *   Package () {
+	 *     Domain Type,			// 0x12:Bluetooth
+	 *     Bluetooth SAR BIOS,		// BIOS SAR Enable/disable
+	 *     Bluetooth Increase Power Mode	// SAR Limitation Enable/disable
+	 *     Bluetooth SAR Power Restriction,	// 00000000 - 0dBm
+	 *					// 11111111 - 31.875dBm
+	 *					// (Step 0.125dBm)
+	 *     Bluetooth SAR Table		// SAR Tx power limit table
+	 *   }
+	 * })
+	 */
+	if (bsar->revision != BSAR_REVISION) {
+		printk(BIOS_ERR, "Unsupported BSAR table revision: %d\n",
+		       bsar->revision);
+		return;
+	}
+
+	acpigen_write_name("BRDS");
+	acpigen_write_package(2);
+	acpigen_write_dword(bsar->revision);
+
+	table_size = sizeof(*bsar) -
+		offsetof(struct bsar_profile, sar_lb_power_restriction);
+	/*
+	 * Emit 'Domain Type' + 'Dynamic SAR Enable' + 'Increase Power Mode'
+	 * + ('SAR Power Restriction' + SAR table).
+	 */
+	package_size = 1 + 1 + 1 + table_size;
+	acpigen_write_package(package_size);
+	acpigen_write_dword(DOMAIN_TYPE_BLUETOOTH);
+	acpigen_write_dword(1);
+	acpigen_write_dword(bsar->increased_power_mode_limitation);
+
+	set = (const uint8_t *)&bsar->sar_lb_power_restriction;
+	for (int i = 0; i < table_size; i++)
+		acpigen_write_byte(set[i]);
+
+	acpigen_write_package_end();
+	acpigen_write_package_end();
+}
+
+static void emit_sar_acpi_structures(const struct device *dev, struct dsm_profile *dsm,
+				     struct bsar_profile *bsar, bool *bsar_loaded)
+{
+	union wifi_sar_limits sar_limits = {0};
 
 	/*
 	 * If device type is PCI, ensure that the device has Intel vendor ID. CBFS SAR and SAR
@@ -516,6 +567,12 @@ static void emit_sar_acpi_structures(const struct device *dev, struct dsm_profil
 	if (sar_limits.dsm != NULL)
 		memcpy(dsm, sar_limits.dsm, sizeof(struct dsm_profile));
 
+	/* copy the bsar data to be later used for creating Bluetooth BRDS method */
+	if (sar_limits.bsar != NULL) {
+		memcpy(bsar, sar_limits.bsar, sizeof(struct bsar_profile));
+		*bsar_loaded = true;
+	}
+
 	free(sar_limits.sar);
 }
 
@@ -576,11 +633,14 @@ static void wifi_ssdt_write_properties(const struct device *dev, const char *sco
 	struct dsm_uuid dsm_ids[MAX_DSM_FUNCS];
 	/* We will need a copy dsm data to be used later for creating _DSM function */
 	struct dsm_profile dsm = {0};
+	/* We will need a copy of bsar data to be used later for creating BRDS function */
+	struct bsar_profile bsar = {0};
+	bool bsar_loaded = false;
 	uint8_t dsm_count = 0;
 
 	/* Fill Wifi SAR related ACPI structures */
 	if (CONFIG(USE_SAR)) {
-		emit_sar_acpi_structures(dev, &dsm);
+		emit_sar_acpi_structures(dev, &dsm, &bsar, &bsar_loaded);
 
 		if (dsm.supported_functions != 0) {
 			for (int i = 1; i < ARRAY_SIZE(wifi_dsm_callbacks); i++)
@@ -618,6 +678,19 @@ static void wifi_ssdt_write_properties(const struct device *dev, const char *sco
 
 	acpigen_write_scope_end(); /* Scope */
 
+	/* Fill Bluetooth companion SAR related ACPI structures */
+	if (bsar_loaded && is_dev_enabled(config->bluetooth_companion)) {
+		const char *path = acpi_device_path(config->bluetooth_companion);
+		if (path) {	/* Bluetooth device under USB Hub scope or PCIe root port */
+			acpigen_write_scope(path);
+			sar_emit_brds(&bsar);
+			acpigen_write_scope_end();
+		} else {
+			printk(BIOS_ERR, "Failed to get %s Bluetooth companion ACPI path\n",
+			       dev_path(dev));
+		}
+	}
+
 	printk(BIOS_INFO, "%s: %s %s\n", scope, dev->chip_ops ? dev->chip_ops->name : "",
 	       dev_path(dev));
 }
diff --git a/src/drivers/wifi/generic/chip.h b/src/drivers/wifi/generic/chip.h
index 2729a35663..302dd144ef 100644
--- a/src/drivers/wifi/generic/chip.h
+++ b/src/drivers/wifi/generic/chip.h
@@ -19,6 +19,9 @@ struct drivers_wifi_generic_config {
 	 * SoC code propagates this value the applicable FSP UPD.
 	 */
 	bool enable_cnvi_ddr_rfim;
+
+	/* Pointer to the Bluetooth companion device */
+	DEVTREE_CONST struct device *bluetooth_companion;
 };
 
 #endif /* _GENERIC_WIFI_H_ */