[PATCH 3/3] ARM: stm32: Add MAC address readout from fuses on DH STM32MP1 DHSOM

[Marek Vasut]

Add support for reading out the MAC address from SoC fuses on DH STM32MP1 DHSOM.
The DH STM32MP1 DHSOM may contain external ethernet MACs, which benefit from the
MAC address stored in SoC fuses as well, handle those consistently. This however
means the architecture setup_mac_address() cannot be used and instead a simpler
local fuse read out is implemented in the board file.

Signed-off-by: Marek Vasut <marek.vasut at mailbox.org>
---
Cc: Patrice Chotard <patrice.chotard at foss.st.com>
Cc: Patrick Delaunay <patrick.delaunay at foss.st.com>
Cc: Tom Rini <trini at konsulko.com>
Cc: u-boot at dh-electronics.com
Cc: u-boot at lists.denx.de
Cc: uboot-stm32 at st-md-mailman.stormreply.com
---
 board/dhelectronics/dh_stm32mp1/board.c | 29 +++++++++++++++++++++++++
 1 file changed, 29 insertions(+)

diff --git a/board/dhelectronics/dh_stm32mp1/board.c b/board/dhelectronics/dh_stm32mp1/board.c
index 065d2f338c2..c18f1911fe4 100644
--- a/board/dhelectronics/dh_stm32mp1/board.c
+++ b/board/dhelectronics/dh_stm32mp1/board.c
@@ -119,6 +119,29 @@ static bool dh_stm32_mac_is_in_ks8851(void)
 	return false;
 }
 
+static int dh_stm32_get_mac_from_fuse(unsigned char *enetaddr, int index)
+{
+	struct udevice *dev;
+	u8 otp[12];
+	int ret;
+
+	ret = uclass_get_device_by_driver(UCLASS_MISC,
+					  DM_DRIVER_GET(stm32mp_bsec),
+					  &dev);
+	if (ret)
+		return ret;
+
+	ret = misc_read(dev, STM32_BSEC_SHADOW(BSEC_OTP_MAC), otp, sizeof(otp));
+	if (ret < 0)
+		return ret;
+
+	memcpy(enetaddr, otp + ARP_HLEN * index, ARP_HLEN);
+	if (!is_valid_ethaddr(enetaddr))
+		return -EINVAL;
+
+	return 0;
+}
+
 static int dh_stm32_setup_ethaddr(struct eeprom_id_page *eip)
 {
 	unsigned char enetaddr[6];
@@ -129,6 +152,9 @@ static int dh_stm32_setup_ethaddr(struct eeprom_id_page *eip)
 	if (dh_get_mac_is_enabled("ethernet0"))
 		return 0;
 
+	if (!dh_stm32_get_mac_from_fuse(enetaddr, 0))
+		goto out;
+
 	if (!dh_get_value_from_eeprom_buffer(DH_MAC0, enetaddr, sizeof(enetaddr), eip))
 		goto out;
 
@@ -154,6 +180,9 @@ static int dh_stm32_setup_eth1addr(struct eeprom_id_page *eip)
 	if (dh_stm32_mac_is_in_ks8851())
 		return 0;
 
+	if (!dh_stm32_get_mac_from_fuse(enetaddr, 1))
+		goto out;
+
 	if (!dh_get_value_from_eeprom_buffer(DH_MAC1, enetaddr, sizeof(enetaddr), eip))
 		goto out;
 
-- 
2.51.0