rockchip: phycore: Read configuration EEPROM & set ethaddr in late init

Read SoM information from EEPROM and set ethaddr in late init.

Signed-off-by: Wadim Egorov <w.egorov@phytec.de>
Acked-by: Philipp Tomsich <philipp.tomsich@theobroma-systems.com>
Reviewed-by: Philipp Tomsich <philipp.tomsich@theobroma-systems.com>

board/phytec/phycore_rk3288/phycore-rk3288.c

@@ -5,4 +5,66 @@
  * SPDX-License-Identifier:     GPL-2.0+
  */
 
+#include <asm/io.h>
 #include <common.h>
+#include <dm.h>
+#include <i2c.h>
+#include <i2c_eeprom.h>
+#include <netdev.h>
+#include "som.h"
+
+static int valid_rk3288_som(struct rk3288_som *som)
+{
+	unsigned char *p = (unsigned char *)som;
+	unsigned char *e = p + sizeof(struct rk3288_som) - 1;
+	int hw = 0;
+
+	while (p < e) {
+		hw += hweight8(*p);
+		p++;
+	}
+
+	return hw == som->bs;
+}
+
+int rk_board_late_init(void)
+{
+	int ret;
+	struct udevice *dev;
+	struct rk3288_som opt;
+	int off;
+
+	/* Get the identificatioin page of M24C32-D EEPROM */
+	off = fdt_path_offset(gd->fdt_blob, "eeprom0");
+	if (off < 0) {
+		printf("%s: No eeprom0 path offset\n", __func__);
+		return off;
+	}
+
+	ret = uclass_get_device_by_of_offset(UCLASS_I2C_EEPROM, off, &dev);
+	if (ret) {
+		printf("%s: Could not find EEPROM\n", __func__);
+		return ret;
+	}
+
+	ret = i2c_set_chip_offset_len(dev, 2);
+	if (ret)
+		return ret;
+
+	ret = i2c_eeprom_read(dev, 0, (uint8_t *)&opt,
+				sizeof(struct rk3288_som));
+	if (ret) {
+		printf("%s: Could not read EEPROM\n", __func__);
+		return ret;
+	}
+
+	if (opt.api_version != 0 || !valid_rk3288_som(&opt)) {
+		printf("Invalid data or wrong EEPROM layout version.\n");
+		/* Proceed anyway, since there is no fallback option */
+	}
+
+	if (is_valid_ethaddr(opt.mac))
+		eth_env_set_enetaddr("ethaddr", opt.mac);
+
+	return 0;
+}

board/phytec/phycore_rk3288/som.h

@@ -0,0 +1,21 @@
+/*
+ * Copyright (C) 2017 PHYTEC Messtechnik GmbH
+ * Author: Wadim Egorov <w.egorov@phytec.de>
+ *
+ * SPDX-License-Identifier:     GPL-2.0+
+ */
+
+/*
+ * rk3288_som struct represents the eeprom layout for PHYTEC RK3288 based SoMs
+ */
+struct rk3288_som {
+	unsigned char api_version;	/* EEPROM layout API version */
+	unsigned char mod_version;	/* PCM/PFL/PCA */
+	unsigned char option[12];	/* coding for variants */
+	unsigned char som_rev;		/* SOM revision */
+	unsigned char mac[6];
+	unsigned char ksp;		/* 1: KSP, 2: KSM */
+	unsigned char kspno;		/* Number for KSP/KSM module */
+	unsigned char reserved[8];	/* not used */
+	unsigned char bs;		/* Bits set in previous bytes */
+} __attribute__ ((__packed__));

configs/phycore-rk3288_defconfig

@@ -46,6 +46,8 @@ CONFIG_CLK=y
 CONFIG_SPL_CLK=y
 CONFIG_ROCKCHIP_GPIO=y
 CONFIG_SYS_I2C_ROCKCHIP=y
+CONFIG_MISC=y
+CONFIG_I2C_EEPROM=y
 CONFIG_MMC_DW=y
 CONFIG_MMC_DW_ROCKCHIP=y
 CONFIG_DM_ETH=y