arm: meson: implement calls to secure monitor

Implement calls to secure monitor to read the MAC address from e-fuse.

Signed-off-by: Beniamino Galvani <b.galvani@gmail.com>
diff --git a/board/hardkernel/odroid-c2/odroid-c2.c b/board/hardkernel/odroid-c2/odroid-c2.c
index c258d4f..bd72100 100644
--- a/board/hardkernel/odroid-c2/odroid-c2.c
+++ b/board/hardkernel/odroid-c2/odroid-c2.c
@@ -7,9 +7,15 @@
 #include <common.h>
 #include <asm/io.h>
 #include <asm/arch/gxbb.h>
+#include <asm/arch/sm.h>
 #include <dm/platdata.h>
 #include <phy.h>
 
+#define EFUSE_SN_OFFSET		20
+#define EFUSE_SN_SIZE		16
+#define EFUSE_MAC_OFFSET	52
+#define EFUSE_MAC_SIZE		6
+
 int board_init(void)
 {
 	return 0;
@@ -27,6 +33,9 @@
 
 int misc_init_r(void)
 {
+	u8 mac_addr[EFUSE_MAC_SIZE];
+	ssize_t len;
+
 	/* Select Ethernet function */
 	setbits_le32(GXBB_PINMUX(6), 0x3fff);
 
@@ -47,5 +56,12 @@
 	mdelay(10);
 	setbits_le32(GXBB_GPIO_OUT(3), BIT(14));
 
+	if (!eth_getenv_enetaddr("ethaddr", mac_addr)) {
+		len = meson_sm_read_efuse(EFUSE_MAC_OFFSET,
+					  mac_addr, EFUSE_MAC_SIZE);
+		if (len == EFUSE_MAC_SIZE && is_valid_ethaddr(mac_addr))
+			eth_setenv_enetaddr("ethaddr", mac_addr);
+	}
+
 	return 0;
 }