wifi: iwlwifi: interpret STEP URM BIOS configuration

For certain platforms, it may necessary to use the STEP in URM
(ultra reliable mode.) Read the necessary flags from the BIOS
(ACPI or UEFI) and indicate the chosen mode to the firmware in
the context info. Whether or not URM really was configured is
already read back later, to adjust capabilities accordingly.

Signed-off-by: Somashekhar(Som) <[email protected]>
Signed-off-by: Johannes Berg <[email protected]>
Reviewed-by: Daniel Gabay <[email protected]>
Signed-off-by: Miri Korenblit <[email protected]>
Link: https://patch.msgid.link/20241227095718.b30024905de3.If3c578af2c15f8005bbe71499bc4091348ed7bb0@changeid
Signed-off-by: Johannes Berg <[email protected]>

1 files changed, 34 insertions, 0 deletions

diff --git a/drivers/net/wireless/intel/iwlwifi/fw/acpi.c b/drivers/net/wireless/intel/iwlwifi/fw/acpi.c
index 7d6e6c80b892..d3ab40fc8ab0 100644
--- a/drivers/net/wireless/intel/iwlwifi/fw/acpi.c
+++ b/drivers/net/wireless/intel/iwlwifi/fw/acpi.c
@@ -1023,3 +1023,37 @@ out_free:
 	kfree(data);
 	return ret;
 }
+
+int iwl_acpi_get_dsbr(struct iwl_fw_runtime *fwrt, u32 *value)
+{
+	union acpi_object *wifi_pkg, *data;
+	int ret = -ENOENT;
+	int tbl_rev;
+
+	data = iwl_acpi_get_object(fwrt->dev, ACPI_DSBR_METHOD);
+	if (IS_ERR(data))
+		return ret;
+
+	wifi_pkg = iwl_acpi_get_wifi_pkg(fwrt->dev, data,
+					 ACPI_DSBR_WIFI_DATA_SIZE,
+					 &tbl_rev);
+	if (IS_ERR(wifi_pkg))
+		goto out_free;
+
+	if (tbl_rev != ACPI_DSBR_WIFI_DATA_REV) {
+		IWL_DEBUG_RADIO(fwrt, "Unsupported ACPI DSBR revision:%d\n",
+				tbl_rev);
+		goto out_free;
+	}
+
+	if (wifi_pkg->package.elements[1].type != ACPI_TYPE_INTEGER)
+		goto out_free;
+
+	*value = wifi_pkg->package.elements[1].integer.value;
+	IWL_DEBUG_RADIO(fwrt, "Loaded DSBR config from ACPI value: 0x%x\n",
+			*value);
+	ret = 0;
+out_free:
+	kfree(data);
+	return ret;
+}