intel/wifi: Create ACPI objects for wifi SAR configuration

To support intel wifi SAR configuration, it is required coreboot
to publish two ACPI objects (WRDS and EWRD) to supply SAR limit
data sets. VPD entry "wifi_sar" is required to supply the raw SAR
limit data.

BUG=chrome-os-partner:60821
TEST=Enable USE_SAR, boot reef to OS, create the VPD entry, reboot,
check the SSDT dump and verify WRDS and EWRD structures.

Change-Id: I6be345735292d0ca46f2f7e7ea61924990d338a8
Signed-off-by: Robbie Zhang <robbie.zhang@intel.com>
Reviewed-on: https://review.coreboot.org/17959
Tested-by: build bot (Jenkins)
Reviewed-by: Aaron Durbin <adurbin@chromium.org>

src/drivers/intel/wifi/Kconfig

@@ -5,3 +5,27 @@ config DRIVERS_INTEL_WIFI
 	help
 	   When enabled, add identifiers in ACPI and SMBIOS tables to
 	   make OS drivers work with certain Intel PCI-e WiFi chipsets.
+
+config USE_SAR
+	bool
+	default n
+	help
+	  Enable it when wifi driver uses SAR configuration feature.
+	  VPD entry "wifi_sar" is required to support it.
+
+config SAR_ENABLE
+	bool
+	default n
+	depends on USE_SAR
+
+config DSAR_ENABLE
+	bool
+	default n
+	depends on USE_SAR
+
+config DSAR_SET_NUM
+	hex "Number of SAR sets when D-SAR is enabled"
+	default 0x3
+	depends on USE_SAR
+	help
+	  There can be up to 3 optional SAR table sets.

src/drivers/intel/wifi/chip.h

@@ -1,3 +1,35 @@
+/*
+ * This file is part of the coreboot project.
+ *
+ * Copyright (C) 2016-2017 Intel Corporation
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; version 2 of the License.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ */
+
+#ifndef _WIFI_CHIP_H_
+#define _WIFI_CHIP_H_
+
+/* WRDS Spec Revision */
+#define WRDS_REVISION 0x0
+
+/* EWRD Spec Revision */
+#define EWRD_REVISION 0x0
+
+/* WRDS Domain type */
+#define WRDS_DOMAIN_TYPE_WIFI 0x7
+
+/* EWRD Domain type */
+#define EWRD_DOMAIN_TYPE_WIFI 0x7
+
 struct drivers_intel_wifi_config {
 	unsigned wake; /* Wake pin for ACPI _PRW */
 };
+
+#endif /* _WIFI_CHIP_H_ */

src/drivers/intel/wifi/wifi.c

@@ -20,6 +20,7 @@
 #include <device/device.h>
 #include <device/pci.h>
 #include <device/pci_ids.h>
+#include <sar.h>
 #include <smbios.h>
 #include <string.h>
 #include <wrdd.h>
@@ -59,6 +60,72 @@ static int smbios_write_wifi(struct device *dev, int *handle,
 #endif
 
 #if IS_ENABLED(CONFIG_HAVE_ACPI_TABLES)
+static void emit_sar_acpi_structures(void)
+{
+	int i, j, package_size;
+	struct wifi_sar_limits sar_limits;
+
+	/* Retrieve the sar limits data */
+	if (get_wifi_sar_limits(&sar_limits) < 0) {
+		printk(BIOS_ERR, "Error: failed from getting SAR limits!\n");
+		return;
+	}
+
+	/*
+	 * Name ("WRDS", Package () {
+	 *   Revision,
+	 *   Package () {
+	 *     Domain Type,	// 0x7:WiFi
+	 *     WiFi SAR BIOS,	// BIOS SAR Enable/disable
+	 *     SAR Table Set	// Set#1 of SAR Table (10 bytes)
+	 *   }
+	 * })
+	 */
+	acpigen_write_name("WRDS");
+	acpigen_write_package(2);
+	acpigen_write_dword(WRDS_REVISION);
+	/* Emit 'Domain Type' + 'WiFi SAR BIOS' + 10 bytes for Set#1 */
+	package_size = 1 + 1 + BYTES_PER_SAR_LIMIT;
+	acpigen_write_package(package_size);
+	acpigen_write_dword(WRDS_DOMAIN_TYPE_WIFI);
+	acpigen_write_dword(CONFIG_SAR_ENABLE);
+	for (i = 0; i < BYTES_PER_SAR_LIMIT; i++)
+		acpigen_write_byte(sar_limits.sar_limit[0][i]);
+	acpigen_pop_len();
+	acpigen_pop_len();
+
+	/*
+	 * Name ("EWRD", Package () {
+	 *   Revision,
+	 *   Package () {
+	 *     Domain Type,		// 0x7:WiFi
+	 *     Dynamic SAR Enable,	// Dynamic SAR Enable/disable
+	 *     Extended SAR sets,	// Number of optional SAR table sets
+	 *     SAR Table Set,		// Set#2 of SAR Table (10 bytes)
+	 *     SAR Table Set,		// Set#3 of SAR Table (10 bytes)
+	 *     SAR Table Set		// Set#4 of SAR Table (10 bytes)
+	 *   }
+	 * })
+	 */
+	acpigen_write_name("EWRD");
+	acpigen_write_package(2);
+	acpigen_write_dword(EWRD_REVISION);
+	/*
+	 * Emit 'Domain Type' + "Dynamic SAR Enable' + 'Extended SAR sets'
+	 * + number of bytes for Set#2 & 3 & 4
+	 */
+	package_size = 1 + 1 + 1 + (NUM_SAR_LIMITS - 1) * BYTES_PER_SAR_LIMIT;
+	acpigen_write_package(package_size);
+	acpigen_write_dword(EWRD_DOMAIN_TYPE_WIFI);
+	acpigen_write_dword(CONFIG_DSAR_ENABLE);
+	acpigen_write_dword(CONFIG_DSAR_SET_NUM);
+	for (i = 1; i < NUM_SAR_LIMITS; i++)
+		for (j = 0; j < BYTES_PER_SAR_LIMIT; j++)
+			acpigen_write_byte(sar_limits.sar_limit[i][j]);
+	acpigen_pop_len();
+	acpigen_pop_len();
+}
+
 static void intel_wifi_fill_ssdt(struct device *dev)
 {
 	struct drivers_intel_wifi_config *config = dev->chip_info;
@@ -105,6 +172,10 @@ static void intel_wifi_fill_ssdt(struct device *dev)
 		acpigen_pop_len();
 	}
 
+	/* Fill Wifi sar related ACPI structures */
+	if (IS_ENABLED(CONFIG_USE_SAR))
+		emit_sar_acpi_structures();
+
 	acpigen_pop_len(); /* Device */
 	acpigen_pop_len(); /* Scope */