sysmocom-odu: read mac addresses from EEPROM

Signed-off-by: Jan Luebbe <jluebbe@debian.org>

arch/arm/boards/phytec-som-am335x/board.c

@@ -32,6 +32,9 @@
 #include <mach/am33xx-generic.h>
 #include <mach/am33xx-silicon.h>
 #include <mach/bbu.h>
+#include <net.h>
+
+#include "sob_odu_eeprom.h"
 
 static int physom_coredevice_init(void)
 {
@@ -124,3 +127,58 @@ static int physom_devices_init(void)
 	return 0;
 }
 device_initcall(physom_devices_init);
+
+#define CRCPOLY_LE 0xedb88320
+static inline u32 __pure crc32_le_generic(u32 crc, unsigned char const *p,
+					  size_t len, u32 polynomial)
+{
+	int i;
+	while (len--) {
+		crc ^= *p++;
+		for (i = 0; i < 8; i++)
+			crc = (crc >> 1) ^ ((crc & 1) ? polynomial : 0);
+	}
+	return crc;
+}
+u32 __pure crc32_le(u32 crc, unsigned char const *p, size_t len)
+{
+	return crc32_le_generic(crc, p, len, CRCPOLY_LE);
+}
+
+static int sob_odu_eeprom_init(void)
+{
+	struct sob_odu_eeprom soe;
+	uint32_t crc32_comp;
+	struct cdev *cdev;
+	int ret;
+
+	if (!of_machine_is_compatible("sysmocom,odu"))
+		return 0;
+
+	cdev = cdev_by_name("eeprom0");
+	if (!cdev)
+		return -ENODEV;
+
+	ret = cdev_read(cdev, &soe, sizeof(soe), 0, 0);
+	if (ret < 0)
+		return ret;
+
+        if (soe.magic != SOBJB_EE_MAGIC || soe.version != SOBJB_EE_VERSION) {
+                pr_err("EEPROM magic/version wrong\n");
+                return -EINVAL;
+        }
+        crc32_comp = crc32_le(0xffffffff, (void *)(&soe) + 8, sizeof(soe)-8);
+        if (soe.crc32 != crc32_comp) {
+                pr_err("EEPROM CRC32 mismatch (eeprom=0x%08x, computed=0x%08x)\n",
+                        soe.crc32, crc32_comp);
+                return -EINVAL;
+        }
+        pr_info("SOB-ODU board v%u, serial number %u, mfg %u, hw_options=0x%08x\n",
+                soe.model, soe.serial, soe.manuf_date, soe.hw_options);
+
+	eth_register_ethaddr(0, soe.mac_eth0);
+	eth_register_ethaddr(1, soe.mac_eth1);
+
+	return 0;
+}
+late_initcall(sob_odu_eeprom_init);

arch/arm/boards/phytec-som-am335x/sob_odu_eeprom.h

@@ -0,0 +1,28 @@
+#pragma once
+
+#define MAC_ADDR_LEN 6
+
+#define SOBJB_EE_MAGIC		0x50b0d0ee
+#define SOBJB_EE_VERSION	1
+
+#define SOB_ODU_V1		1
+#define SOB_ODU_V2		2
+#define SOB_ODU_V3		3
+
+struct sob_odu_eeprom {
+	uint32_t magic;		/* SOBJB_EE_MAGIC */
+	uint32_t crc32;		/* crc32_le */
+
+	uint16_t len;		/* sizeof(struct sob_odu_eeprom) */
+	uint8_t version;	/* SOBJB_EE_VERSION */
+	uint8_t model;		/* SOB_ODU_V* */
+
+	uint32_t serial;
+	uint32_t manuf_date;
+	uint32_t hw_options;
+
+	uint8_t mac_eth0[MAC_ADDR_LEN];
+	uint8_t mac_eth1[MAC_ADDR_LEN];
+	uint8_t mac_wlan0[MAC_ADDR_LEN];
+	uint8_t mac_wlan1[MAC_ADDR_LEN];
+} __attribute__ ((packed));