[PATCH v2 05/10] boards: enclustra-sa2: read MAC address from EEPROM

[David Picard <david.picard@clermont.in2p3.fr>]

Signed-off-by: David Picard <david.picard@clermont.in2p3.fr>

---
v1 --> v2:
  - Use the atsha204a driver to read the MAC address instead of
    board-specific code.
---
---
 arch/arm/boards/enclustra-sa2/board.c          | 74 +++++++++++++++++++++++++-
 arch/arm/dts/socfpga_cyclone5_mercury_sa2.dtsi | 16 +++++-
 2 files changed, 87 insertions(+), 3 deletions(-)

diff --git a/arch/arm/boards/enclustra-sa2/board.c b/arch/arm/boards/enclustra-sa2/board.c
index d3117e9a1058738ea541f45b28c6a95184331554..4c2b44252d84c78ed8de5754051d0bf194ce8d02 100644
--- a/arch/arm/boards/enclustra-sa2/board.c
+++ b/arch/arm/boards/enclustra-sa2/board.c
@@ -12,6 +12,12 @@
 #include <fcntl.h>
 #include <fs.h>
 #include <mach/socfpga/cyclone5-regs.h>
+#include <net.h>
+#include <linux/nvmem-consumer.h>
+
+/** Enclustra's MAC address vendor prefix is 20:B0:F7 */
+#define ENCLUSTRA_PREFIX            (0x20b0f7)
+#define MAC_ADDR_NUM_BYTES          (6)
 
 /*
  * Ethernet PHY: Microchip/Micrel KSZ9031RNX
@@ -21,14 +27,78 @@ static int phy_fixup(struct phy_device *dev)
 	return 0;
 }
 
+/*
+ * Read the MAC address via the atsha204a driver.
+ *
+ * Set two consecutive MAC addresses, as specified by the manufacturer.
+ */
+static void set_mac_addr(void)
+{
+	uint8_t hwaddr[MAC_ADDR_NUM_BYTES] = { 0, 0, 0, 0, 0, 0 };
+	uint32_t hwaddr_prefix;
+	u8 *data = NULL;
+	static const char * const aliases[] = { "ethernet0" };
+	struct device_node *np, *root;
+	/* Fallback MAC addresses, used if we can't read from EEPROM: */
+	const uint8_t enclustra_ethaddr_fallback1[] = { 0x20, 0xB0, 0xF7, 0x01,
+													0x02, 0x03 };
+	const uint8_t enclustra_ethaddr_fallback2[] = { 0x20, 0xB0, 0xF7, 0x01,
+													0x02, 0x04 };
+
+	root = of_get_root_node();
+
+	for (int i = 0; i < ARRAY_SIZE(aliases); i++) {
+		const char *alias = aliases[i];
+		np = of_find_node_by_alias(root, alias);
+		if (!np) {
+			pr_warn("%s() >> ERROR: can't find alias %s\n", __func__, alias);
+			continue;
+		}
+		data = nvmem_cell_get_and_read(np, "mac-address", MAC_ADDR_NUM_BYTES);
+		if (IS_ERR(data)) {
+			pr_warn("%s() >> ERROR: can't read NVMEM cell\n", __func__);
+			data = NULL;
+		}
+	}
+	if (!data)
+		goto fallback_addr;
+
+	memcpy(hwaddr, data, MAC_ADDR_NUM_BYTES);
+
+	debug("MAC address: %02x:%02x:%02x:%02x:%02x:%02x\n",
+		  hwaddr[0], hwaddr[1], hwaddr[2],
+		  hwaddr[3], hwaddr[4], hwaddr[5]);
+
+	/* check vendor prefix and set the environment variable */
+	hwaddr_prefix = (hwaddr[0] << 16) | (hwaddr[1] << 8) | (hwaddr[2]);
+	if (hwaddr_prefix == ENCLUSTRA_PREFIX) {
+		eth_register_ethaddr(0, hwaddr);
+		hwaddr[5]++;    /* calculate 2nd, consecutive MAC address */
+		eth_register_ethaddr(1, hwaddr);
+	} else {
+		printf("%s() >> ERROR: invalid MAC address vendor prefix,"
+			   "using fallback addresses\n", __func__);
+		goto fallback_addr;
+	}
+
+	return;
+
+fallback_addr:
+	eth_register_ethaddr(0, enclustra_ethaddr_fallback1);
+	eth_register_ethaddr(1, enclustra_ethaddr_fallback2);
+}
+
 static int socfpga_init(void)
 {
 	if (!of_machine_is_compatible("enclustra,mercury-sa2"))
 		return 0;
 
 	if (IS_ENABLED(CONFIG_PHYLIB))
-		phy_register_fixup_for_uid(PHY_ID_KSZ9031, MICREL_PHY_ID_MASK, phy_fixup);
+		phy_register_fixup_for_uid(PHY_ID_KSZ9031, MICREL_PHY_ID_MASK,
+								   phy_fixup);
+
+	set_mac_addr();
 
 	return 0;
 }
-console_initcall(socfpga_init);
+late_initcall(socfpga_init);
diff --git a/arch/arm/dts/socfpga_cyclone5_mercury_sa2.dtsi b/arch/arm/dts/socfpga_cyclone5_mercury_sa2.dtsi
index fa80b7c63d28d17a24d63ac3ee87531ad320ddb1..55d54d289c81fa4a6d46123bcb93c5fc483485e4 100644
--- a/arch/arm/dts/socfpga_cyclone5_mercury_sa2.dtsi
+++ b/arch/arm/dts/socfpga_cyclone5_mercury_sa2.dtsi
@@ -76,6 +76,19 @@ atsha204a: atsha204a@64 {
 		status = "okay";
 		compatible = "atmel,atsha204a";
 		reg = <0x64>;
+
+		nvmem-layout {
+		compatible = "fixed-layout";
+		#address-cells = <1>;
+		#size-cells = <1>;
+
+			mac_address_0: mac@10 {
+				compatible = "mac-base";
+				reg = <0x10 0x6>;
+				nvmem-cell-cells = <1>;
+				nvmem-cell-names = "mac-address";
+			};
+		};
 	};
 };
 
@@ -129,9 +142,10 @@ &gpio1 {
 
 &gmac1 {
 	status = "okay";
-	/delete-property/ mac-address;
 	phy-mode = "rgmii";
 	phy-handle = <&phy3>;
+	nvmem-cells = <&mac_address_0>;
+	nvmem-cell-names = "mac-address";
 
 	mdio0 {
 		#address-cells = <1>;

-- 
2.43.0