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/* SPDX-License-Identifier: GPL-2.0-only */
#include <cbfs.h>
#include <console/console.h>
#include <lib.h>
#include <types.h>
#include <string.h>
#include <sar.h>
#include <drivers/vpd/vpd.h>
#define WIFI_SAR_CBFS_FILENAME "wifi_sar_defaults.hex"
#define CROS_VPD_WIFI_SAR_NAME "wifi_sar"
static int load_sar_file_from_cbfs(void *buf, size_t buffer_size)
{
const char *filename = get_wifi_sar_cbfs_filename();
if (filename == NULL)
filename = WIFI_SAR_CBFS_FILENAME;
return cbfs_load(filename, buf, buffer_size);
}
/* 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;
/* 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 the buffer size. */
char wifi_sar_limit_str[2 * sizeof(struct wifi_sar_limits) + 1];
uint8_t bin_buffer[sizeof(struct wifi_sar_limits)];
const size_t buffer_size = ARRAY_SIZE(wifi_sar_limit_str);
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 (!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 (!vpd_gets(wifi_sar_limit_key, wifi_sar_limit_str,
buffer_size, VPD_RO_THEN_RW)) {
printk(BIOS_DEBUG, "Could not locate '%s' in VPD.\n",
wifi_sar_limit_key);
if (!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;
}
}
/* Decode the heximal encoded string to binary values */
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;
}
memset(sar_limits, 0, sizeof(*sar_limits));
memcpy(sar_limits, bin_buffer, bin_buff_adjusted_size);
return 0;
}
__weak
const char *get_wifi_sar_cbfs_filename(void)
{
return WIFI_SAR_CBFS_FILENAME;
}
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