efuse: Don't need to burn WR_CRYPT_CNT if CRYPT_CNT is already max

Reduces write cycles, and useful on ESP32 ECO3 as UART_DIS_DL is protected by
the same efuse.

Also fixes accidental macro definition introduced in 7635dce502b4de8fa8a32ae9a140e82fc3a72eb5

components/bootloader_support/src/flash_encrypt.c

@@ -21,10 +21,10 @@
 #include "esp_secure_boot.h"
 
 #if CONFIG_IDF_TARGET_ESP32
-#define CRYPT_CNT ESP_EFUSE_WR_DIS_FLASH_CRYPT_CNT
+#define CRYPT_CNT ESP_EFUSE_FLASH_CRYPT_CNT
 #define WR_DIS_CRYPT_CNT ESP_EFUSE_WR_DIS_FLASH_CRYPT_CNT
 #elif CONFIG_IDF_TARGET_ESP32S2
-#define CRYPT_CNT ESP_EFUSE_WR_DIS_SPI_BOOT_CRYPT_CNT
+#define CRYPT_CNT ESP_EFUSE_SPI_BOOT_CRYPT_CNT
 #define WR_DIS_CRYPT_CNT ESP_EFUSE_WR_DIS_SPI_BOOT_CRYPT_CNT
 #endif
 
@@ -42,8 +42,15 @@ void esp_flash_encryption_init_checks()
 #ifdef CONFIG_SECURE_BOOT
     if (esp_secure_boot_enabled() && esp_flash_encryption_enabled()) {
         uint8_t flash_crypt_cnt_wr_dis = 0;
-        esp_efuse_read_field_blob(CRYPT_CNT, &flash_crypt_cnt_wr_dis, 1);
+        esp_efuse_read_field_blob(WR_DIS_CRYPT_CNT, &flash_crypt_cnt_wr_dis, 1);
         if (!flash_crypt_cnt_wr_dis) {
+            uint8_t flash_crypt_cnt = 0;
+            esp_efuse_read_field_blob(CRYPT_CNT, &flash_crypt_cnt,  CRYPT_CNT[0]->bit_count);
+            if (flash_crypt_cnt == (1<<(CRYPT_CNT[0]->bit_count))-1) {
+                // If encryption counter is already max, no need to write protect it
+                // (this distinction is important on ESP32 ECO3 where write-procted FLASH_CRYPT_CNT also write-protects UART_DL_DIS)
+                return;
+            }
             ESP_EARLY_LOGE(TAG, "Flash encryption & Secure Boot together requires FLASH_CRYPT_CNT efuse to be write protected. Fixing now...");
             esp_flash_write_protect_crypt_cnt();
         }
@@ -71,7 +78,7 @@ void esp_flash_write_protect_crypt_cnt(void)
 {
     uint8_t flash_crypt_cnt_wr_dis = 0;
 
-    esp_efuse_read_field_blob(CRYPT_CNT, &flash_crypt_cnt_wr_dis, 1);
+    esp_efuse_read_field_blob(WR_DIS_CRYPT_CNT, &flash_crypt_cnt_wr_dis, 1);
 
     if (!flash_crypt_cnt_wr_dis) {
         esp_efuse_write_field_cnt(WR_DIS_CRYPT_CNT, 1);