[PATCH 7/9] ARM: socfpga: AA1: support MAC from secure eeprom

[Lothar Rubusch <l.rubusch@gmail.com>]

Several Enclustra devices store MAC address in a secure eeprom device. In
most cases this is the atsha204a (alternatively DS28). The atsha204a device
is preconfigured accordingly. Reading then is based on u-boot's atsha204a
driver. Add such support for Enclustra's AA1 SoMs.

Signed-off-by: Lothar Rubusch <l.rubusch@gmail.com>
---
 board/enclustra/common/Kconfig                | 23 +++++
 board/enclustra/common/Makefile               |  3 +
 board/enclustra/common/enclustra_mac.h        | 48 +++++++++
 board/enclustra/common/mac_atsha204.c         | 97 +++++++++++++++++++
 board/enclustra/common/mac_common.c           | 54 +++++++++++
 board/enclustra/common/mac_ds28.c             | 88 +++++++++++++++++
 board/enclustra/mercury_aa1/mercury_aa1.c     |  7 ++
 .../socfpga_enclustra_mercury_aa1_defconfig   |  1 +
 drivers/misc/Kconfig                          |  2 +-
 9 files changed, 322 insertions(+), 1 deletion(-)
 create mode 100644 board/enclustra/common/enclustra_mac.h
 create mode 100644 board/enclustra/common/mac_atsha204.c
 create mode 100644 board/enclustra/common/mac_common.c
 create mode 100644 board/enclustra/common/mac_ds28.c

diff --git a/board/enclustra/common/Kconfig b/board/enclustra/common/Kconfig
index 51169bada3..51991f7882 100644
--- a/board/enclustra/common/Kconfig
+++ b/board/enclustra/common/Kconfig
@@ -1 +1,24 @@
+config ENCLUSTRA_EEPROM_MAC
+	bool "Enclustra MAC address"
+	select ATSHA204A
+	default y if TARGET_SOCFPGA_ENCLUSTRA_MERCURY_AA1
+	help
+	  Reads the MAC address out of the EEPROM and configures the MAC
+	  addresses in the environment.
+
+choice
+	prompt "Enclustra EEPROM device"
+	depends on ENCLUSTRA_EEPROM_MAC
+	default ENCLUSTRA_EEPROM_MAC_ATSHA204 if TARGET_SOCFPGA_ENCLUSTRA_MERCURY_AA1
+	help
+	  Specify the device where the MAC is stored.
+
+config ENCLUSTRA_EEPROM_MAC_ATSHA204
+	bool "MAC stored in 'ATSHA204'"
+
+config ENCLUSTRA_EEPROM_MAC_DS28
+	bool "MAC stored in 'DS28'"
+
+endchoice
+
 source "board/enclustra/mercury_aa1/Kconfig"
diff --git a/board/enclustra/common/Makefile b/board/enclustra/common/Makefile
index 16c8531d74..c83743abe7 100644
--- a/board/enclustra/common/Makefile
+++ b/board/enclustra/common/Makefile
@@ -2,3 +2,6 @@
 # Copyright (c) 2024 Enclustra GmbH
 
 # Common for several Enclustra modules
+obj-$(CONFIG_ENCLUSTRA_EEPROM_MAC) += mac_common.o
+obj-$(CONFIG_ENCLUSTRA_EEPROM_MAC_ATSHA204) += mac_atsha204.o
+obj-$(CONFIG_ENCLUSTRA_EEPROM_MAC_DS28) += mac_ds28.o
diff --git a/board/enclustra/common/enclustra_mac.h b/board/enclustra/common/enclustra_mac.h
new file mode 100644
index 0000000000..9631e9d458
--- /dev/null
+++ b/board/enclustra/common/enclustra_mac.h
@@ -0,0 +1,48 @@
+/* SPDX-License-Identifier: GPL-2.0+
+ *
+ * Copyright 2024 Enclustra GmbH, <info@enclustra.com>
+ */
+
+#ifndef ENCLUSTRA_MAC
+# define ENCLUSTRA_MAC               0xF7B020
+#endif
+
+/*
+ * enclustra_mac_is_in_env - Check if MAC address is already set
+ *
+ * @env: name of the environment variable
+ * Return: true if MAC is set, false otherwise
+ */
+bool enclustra_mac_is_in_env(const char *env);
+
+/*
+ * enclustra_get_mac_is_enabled - Test if ethernet MAC is enabled in DT
+ *
+ * @alias: alias for ethernet MAC device tree node
+ * Return: 0 if OK, other value on error
+ */
+int enclustra_get_mac_is_enabled(const char *alias);
+
+/*
+ * enclustra_get_mac_from_eeprom - Get MAC address from eeprom and write it to enetaddr
+ *
+ * @enetaddr: buffer where address is to be stored
+ * @alias: alias for EEPROM device tree node
+ * Return: 0 if OK, other value on error
+ */
+int enclustra_get_mac_from_eeprom(unsigned char *enetaddr, const char *alias);
+
+/*
+ * enclustra_get_mac1_from_mac - Get MAC1 address from MAC and write it to enetaddr
+ *
+ * @enetaddr: buffer where MAC is passed, MAC will be modified to MAC1
+ * Return: 0 if OK, else error value
+ */
+int enclustra_get_mac1_from_mac(unsigned char *enetaddr);
+
+/*
+ * enclustra_setup_mac_address - Try to get MAC address from various locations and write it to env
+ *
+ * Return: 0 if OK, other value on error
+ */
+int enclustra_setup_mac_address(void);
diff --git a/board/enclustra/common/mac_atsha204.c b/board/enclustra/common/mac_atsha204.c
new file mode 100644
index 0000000000..4bd25505d6
--- /dev/null
+++ b/board/enclustra/common/mac_atsha204.c
@@ -0,0 +1,97 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Copyright (c) 2024 Enclustra GmbH
+ */
+
+#include <dm.h>
+#include <atsha204a-i2c.h>
+#include <net.h>
+
+#include "enclustra_mac.h"
+
+int enclustra_get_mac_from_eeprom(unsigned char *enetaddr, const char *alias)
+{
+	struct udevice *dev;
+	u32 hwaddr_h;
+	u8 data[4];
+	int i, j, eeprom_addr, mac_len, ret;
+
+	ret = uclass_get_device_by_name(UCLASS_MISC, alias, &dev);
+	if (ret) {
+		printf("%s: Failed, cannot find EEPROM! ret = %d\n", __func__, ret);
+		return ret;
+	}
+
+	/* Make sure atsha204a is in a defined state (part of protocol) */
+	if (atsha204a_sleep(dev)) {
+		printf("%s(): Failed to bring EEPROM in defined state\n", __func__);
+		return -ENODEV;
+	}
+
+	if (atsha204a_wakeup(dev)) {
+		printf("%s(): Failed to wakeup EEPROM\n", __func__);
+		return -ENODEV;
+	}
+
+	/* Read twice portions of 4 bytes (atsha204 protocol). One from address 4
+	 * the other from address 5 of the OTP zone. Then convert the data to
+	 * the 6 elements of the MAC address.
+	 */
+	eeprom_addr = 4;
+	mac_len = 6;
+	for (i = 0; i < 2; i++) {
+		eeprom_addr += i;
+		if (atsha204a_read(dev, ATSHA204A_ZONE_OTP, false, eeprom_addr, data)) {
+			printf("%s(): Failed to parse ATSHA204A_ZONE_OTP of EEPROM\n",
+			       __func__);
+			return -EFAULT;
+		}
+
+		for (j = 0; j < 4 && j + i * 4 < mac_len; j++)
+			enetaddr[j + i * 4] = data[j];
+	}
+
+	/* Check if the value is a valid mac registered for
+	 * Enclustra  GmbH
+	 */
+	hwaddr_h = enetaddr[0] | enetaddr[1] << 8 | enetaddr[2] << 16;
+	if ((hwaddr_h & 0xFFFFFF) != ENCLUSTRA_MAC) {
+		printf("%s(): Failed, parsed MAC is no Enclustra MAC\n", __func__);
+		return -ENOENT;
+	}
+
+	if (!is_valid_ethaddr(enetaddr)) {
+		printf("%s(): Failed, address read from EEPROM is invalid!\n",
+		       __func__);
+		return -EINVAL;
+	}
+
+	printf("ethaddr set to %02X:%02X:%02X:%02X:%02X:%02X\n",
+	       enetaddr[0], enetaddr[1], enetaddr[2],
+	       enetaddr[3], enetaddr[4], enetaddr[5]);
+
+	return 0;
+}
+
+__weak int enclustra_setup_mac_address(void)
+{
+	unsigned char enetaddr[6];
+
+	if (enclustra_mac_is_in_env("ethaddr"))
+		return 0;
+
+	if (enclustra_get_mac_is_enabled("ethernet0"))
+		return 0;
+
+	if (enclustra_get_mac_from_eeprom(enetaddr, "atsha204a@64"))
+		return -ENXIO;
+
+	if (eth_env_set_enetaddr("ethaddr", enetaddr))
+		return -ENXIO;
+
+	if (!enclustra_get_mac1_from_mac(enetaddr))
+		return eth_env_set_enetaddr("eth1addr", enetaddr);
+
+	printf("%s(): Failed, unable to set mac address!\n", __func__);
+	return -ENXIO;
+}
diff --git a/board/enclustra/common/mac_common.c b/board/enclustra/common/mac_common.c
new file mode 100644
index 0000000000..cf5dac0e0e
--- /dev/null
+++ b/board/enclustra/common/mac_common.c
@@ -0,0 +1,54 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Copyright (c) 2024 Enclustra GmbH
+ */
+
+#include <dm.h>
+#include <atsha204a-i2c.h>
+#include <net.h>
+
+#include "enclustra_mac.h"
+
+bool enclustra_mac_is_in_env(const char *env)
+{
+	unsigned char enetaddr[6];
+
+	return eth_env_get_enetaddr(env, enetaddr);
+}
+
+int enclustra_get_mac_is_enabled(const char *alias)
+{
+	ofnode node =   ofnode_path(alias);
+
+	if (!ofnode_valid(node))
+		return -EINVAL;
+
+	if (!ofnode_is_enabled(node))
+		return -EINVAL;
+
+	return 0;
+}
+
+int enclustra_get_mac1_from_mac(unsigned char *enetaddr)
+{
+	u32 hwaddr_h;
+
+	/* Increment MAC addr */
+	hwaddr_h = (enetaddr[3] << 16) | (enetaddr[4] << 8) | enetaddr[5];
+	hwaddr_h = (hwaddr_h + 1) & 0xFFFFFF;
+	enetaddr[3] = (hwaddr_h >> 16) & 0xFF;
+	enetaddr[4] = (hwaddr_h >> 8) & 0xFF;
+	enetaddr[5] = hwaddr_h & 0xFF;
+
+	if (!is_valid_ethaddr(enetaddr)) {
+		printf("%s(): Failed, address computed from enetaddr is invalid!\n",
+		       __func__);
+		return -EINVAL;
+	}
+
+	printf("eth1addr set to %02X:%02X:%02X:%02X:%02X:%02X\n",
+	       enetaddr[0], enetaddr[1], enetaddr[2],
+	       enetaddr[3], enetaddr[4], enetaddr[5]);
+
+	return 0;
+}
diff --git a/board/enclustra/common/mac_ds28.c b/board/enclustra/common/mac_ds28.c
new file mode 100644
index 0000000000..9aed4f1de1
--- /dev/null
+++ b/board/enclustra/common/mac_ds28.c
@@ -0,0 +1,88 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Copyright (c) 2024 Enclustra GmbH
+ */
+
+#include <linux/compat.h>
+#include <dm.h>
+#include <i2c.h>
+#include <net.h>
+
+#include "enclustra_mac.h"
+
+#define DS28_I2C_ADDR 0x5C
+#define DS28_SYS_I2C_EEPROM_BUS 0
+
+int enclustra_get_mac_from_eeprom(unsigned char *enetaddr, const char *alias)
+{
+	struct udevice *dev;
+	u32 hwaddr_h;
+	struct dm_i2c_chip *chip;
+	uint chip_addr = DS28_I2C_ADDR;
+	int alen = 1;
+	int ret;
+
+	if (i2c_get_chip_for_busnum(DS28_SYS_I2C_EEPROM_BUS, chip_addr,
+				    alen, &dev))
+		return -ENODEV;
+
+	chip = dev_get_parent_plat(dev);
+	if (chip->offset_len != alen) {
+		debug("I2C chip %x: alen %d does not match offset_len %d\n",
+		      chip_addr, alen, chip->offset_len);
+		return -EADDRNOTAVAIL;
+	}
+
+	ret = dm_i2c_read(dev, 0x10, enetaddr, 6);
+	if (ret) {
+		printf("%s(): Failed reading EEPROM! ret = %d\n", __func__, ret);
+		return ret;
+	}
+
+	/* Check if the value is a valid mac registered for
+	 * Enclustra  GmbH
+	 */
+	hwaddr_h = enetaddr[0] | enetaddr[1] << 8 | enetaddr[2] << 16;
+	if ((hwaddr_h & 0xFFFFFF) != ENCLUSTRA_MAC) {
+		printf("%s(): Failed, parsed MAC is no Enclustra MAC\n", __func__);
+		return -ENOENT;
+	}
+
+	if (!is_valid_ethaddr(enetaddr)) {
+		printf("%s(): Failed, address read from EEPROM is invalid!\n",
+		       __func__);
+		return -EINVAL;
+	}
+
+	printf("ethaddr set to %02X:%02X:%02X:%02X:%02X:%02X\n",
+	       enetaddr[0], enetaddr[1], enetaddr[2],
+	       enetaddr[3], enetaddr[4], enetaddr[5]);
+
+	return 0;
+}
+
+__weak int enclustra_setup_mac_address(void)
+{
+	unsigned char enetaddr[6];
+
+	if (enclustra_mac_is_in_env("ethaddr"))
+		return 0;
+
+	if (enclustra_get_mac_is_enabled("ethernet0"))
+		return 0;
+
+	// NB: DS28 is still not available in official DT, so referencing
+	// here by i2c busnumber and address directly
+	// preparation for DT access here, though
+	if (enclustra_get_mac_from_eeprom(enetaddr, ""))
+		return -ENXIO;
+
+	if (eth_env_set_enetaddr("ethaddr", enetaddr))
+		return -ENXIO;
+
+	if (!enclustra_get_mac1_from_mac(enetaddr))
+		return eth_env_set_enetaddr("eth1addr", enetaddr);
+
+	printf("%s(): Failed, unable to set mac address!\n", __func__);
+	return -ENXIO;
+}
diff --git a/board/enclustra/mercury_aa1/mercury_aa1.c b/board/enclustra/mercury_aa1/mercury_aa1.c
index 7de9b287d9..c53ae128f0 100644
--- a/board/enclustra/mercury_aa1/mercury_aa1.c
+++ b/board/enclustra/mercury_aa1/mercury_aa1.c
@@ -11,6 +11,8 @@
 #include <asm-generic/gpio.h>
 #include <asm/io.h>
 
+#include "../common/enclustra_mac.h"
+
 /* Pin muxing */
 #if !defined(CONFIG_SPL_BUILD)
 
@@ -27,6 +29,11 @@ static int altera_current_storage = ALTERA_NONE;
 
 #endif
 
+int board_late_init(void)
+{
+	return enclustra_setup_mac_address();
+}
+
 #if !defined(CONFIG_SPL_BUILD)
 
 static void set_mux_mmc(void)
diff --git a/configs/socfpga_enclustra_mercury_aa1_defconfig b/configs/socfpga_enclustra_mercury_aa1_defconfig
index b475bd916d..58c718864b 100644
--- a/configs/socfpga_enclustra_mercury_aa1_defconfig
+++ b/configs/socfpga_enclustra_mercury_aa1_defconfig
@@ -26,6 +26,7 @@ CONFIG_SYS_CONSOLE_IS_IN_ENV=y
 CONFIG_SYS_CONSOLE_OVERWRITE_ROUTINE=y
 CONFIG_SYS_CONSOLE_ENV_OVERWRITE=y
 CONFIG_DISPLAY_BOARDINFO_LATE=y
+CONFIG_BOARD_LATE_INIT=y
 CONFIG_CLOCKS=y
 CONFIG_SPL_PAD_TO=0x40000
 CONFIG_SPL_NO_BSS_LIMIT=y
diff --git a/drivers/misc/Kconfig b/drivers/misc/Kconfig
index 6009d55f40..90fa8c9eae 100644
--- a/drivers/misc/Kconfig
+++ b/drivers/misc/Kconfig
@@ -73,7 +73,7 @@ config ATSHA204A
 	help
 	   Enable support for I2C connected Atmel's ATSHA204A
 	   CryptoAuthentication module found for example on the Turris Omnia
-	   board.
+	   board and Enclustra SoC FPGA boards.
 
 config GATEWORKS_SC
 	bool "Gateworks System Controller Support"
-- 
2.25.1