1 files changed, 83 insertions, 24 deletions

diff --git a/src/vendorcode/google/chromeos/sar.c b/src/vendorcode/google/chromeos/sar.c
index 954492b822..fc72dc1348 100644
--- a/src/vendorcode/google/chromeos/sar.c
+++ b/src/vendorcode/google/chromeos/sar.c
@@ -1,7 +1,7 @@
 /*
  * This file is part of the coreboot project.
  *
- * Copyright (C) 2017 Intel Corp.
+ * Copyright (C) 2017-2018 Intel Corp.
  *
  * 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
@@ -12,6 +12,8 @@
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  * GNU General Public License for more details.
  */
+
+#include <cbfs.h>
 #include <console/console.h>
 #include <lib.h>
 #include <types.h>
@@ -19,44 +21,101 @@
 #include <sar.h>
 #include "cros_vpd.h"
 
-/* Retrieve the wifi SAR limits data from VPD and decode it */
+#define WIFI_SAR_CBFS_FILENAME	"wifi_sar_defaults.hex"
+
+static int load_sar_file_from_cbfs(void *buf, size_t buffer_size)
+{
+	return cbfs_boot_load_file(WIFI_SAR_CBFS_FILENAME, buf,
+			buffer_size, CBFS_TYPE_RAW);
+}
+
+/* Retrieve the wifi SAR limits data from VPD and decode it
+
+For VPD: key,value pair is in this format
+"wifi_sar"=[<WRDD><EWRD>][WGDS]
+
+WIFI SAR data in CBFS file is expected in same format: [<WRDD><EWRD>][WGDS]
+
+[<WRDD><EWRD>] = NUM_SAR_LIMITS * BYTES_PER_SAR_LIMIT bytes.
+[WGDS]=[WGDS_VERSION][WGDS_DATA]
+
+For [WGDS_VERSION] 0x00,
+[WGDS_DATA] = [GROUP#0][GROUP#1][GROUP#2]
+
+[GROUP#<i>] =
+	[2.4Ghz – Max Allowed][2.4Ghz – Chain A Offset]
+	[2.4Ghz – Chain B Offset][5Ghz – Max Allowed]
+	[5Ghz – Chain A Offset][5Ghz – Chain B Offset]
+
+[GROUP#0] is for FCC
+[GROUP#1] is for Europe/Japan
+[GROUP#2] is for ROW
+
+*/
 int get_wifi_sar_limits(struct wifi_sar_limits *sar_limits)
 {
 	const char *wifi_sar_limit_key = CROS_VPD_WIFI_SAR_NAME;
-	/*
-	 * cros_vpd_gets() reads in one less than size characters from the VPD
+	/* cros_vpd_gets() reads in one less than size characters from the VPD
 	 * with a terminating null byte ('\0') stored as the last character into
-	 * the buffer, thus the increasing by 1 for buffer_size.
-	 */
+	 * the buffer, thus the increasing by 1 for buffer_size. */
 	const size_t buffer_size = (sizeof(struct wifi_sar_limits) /
-				    sizeof(uint8_t)) * 2 + 1;
+					sizeof(uint8_t)) * 2 + 1;
 	char wifi_sar_limit_str[buffer_size];
 	uint8_t bin_buffer[sizeof(struct wifi_sar_limits)];
-	int i;
+	size_t sar_cbfs_len, sar_expected_len, bin_buff_adjusted_size;
+
+	/* keep it backward compatible. Some older platform are shipping
+	   without GEO SAR and so older wifi_sar VPD key */
+
+	sar_expected_len = buffer_size;
+	bin_buff_adjusted_size = sizeof(struct wifi_sar_limits);
+
+	if (!IS_ENABLED(CONFIG_GEO_SAR_ENABLE)) {
+		sar_expected_len = buffer_size -
+					sizeof(struct wifi_sar_delta_table) *
+					sizeof(uint8_t) * 2;
+		bin_buff_adjusted_size = sizeof(struct wifi_sar_limits) -
+					 sizeof(struct wifi_sar_delta_table);
+	}
 
 	/* Try to read the SAR limit entry from VPD */
 	if (!cros_vpd_gets(wifi_sar_limit_key, wifi_sar_limit_str,
-		ARRAY_SIZE(wifi_sar_limit_str))) {
-		printk(BIOS_ERR,
-			"Error: Could not locate '%s' in VPD\n",
-			wifi_sar_limit_key);
-		return -1;
+							 buffer_size)) {
+		printk(BIOS_ERR, "Error: Could not locate '%s' in VPD.\n",
+				wifi_sar_limit_key);
+
+		if (!IS_ENABLED(CONFIG_WIFI_SAR_CBFS))
+			return -1;
+
+		printk(BIOS_DEBUG, "Checking CBFS for default SAR values\n");
+
+		sar_cbfs_len = load_sar_file_from_cbfs(
+					(void *) wifi_sar_limit_str,
+						sar_expected_len);
+
+		if (sar_cbfs_len != sar_expected_len) {
+			printk(BIOS_ERR, "%s has bad len in CBFS\n",
+					WIFI_SAR_CBFS_FILENAME);
+			return -1;
+		}
+	} else {
+		/* VPD key "wifi_sar" found. strlen is checked with addition of
+		 * 1 as we have created buffer size 1 char larger for the reason
+		 * mentioned at start of this function itself */
+		if (strlen(wifi_sar_limit_str) + 1 != sar_expected_len) {
+			printk(BIOS_ERR, "WIFI SAR key has bad len in VPD\n");
+			return -1;
+		}
 	}
-	printk(BIOS_DEBUG, "VPD wifi_sar = %s\n", wifi_sar_limit_str);
 
 	/* Decode the heximal encoded string to binary values */
-	if (hexstrtobin(wifi_sar_limit_str, bin_buffer,
-			sizeof(struct wifi_sar_limits))
-			< sizeof(struct wifi_sar_limits)) {
-		printk(BIOS_ERR,
-			"Error: VPD wifi_sar contains non-heximal value!\n");
+	if (hexstrtobin(wifi_sar_limit_str, bin_buffer, bin_buff_adjusted_size)
+			< bin_buff_adjusted_size) {
+		printk(BIOS_ERR, "Error: wifi_sar contains non-hex value!\n");
 		return -1;
 	}
 
-	/* Fill the sar_limits structure with the decoded data */
-	for (i = 0; i < NUM_SAR_LIMITS; i++)
-		memcpy(sar_limits->sar_limit[i],
-			&bin_buffer[BYTES_PER_SAR_LIMIT * i],
-			BYTES_PER_SAR_LIMIT);
+	memset(sar_limits, 0, sizeof(*sar_limits));
+	memcpy(sar_limits, bin_buffer, bin_buff_adjusted_size);
 	return 0;
 }