rockchip: rk3399: derive ethaddr from cpuid

Generate a MAC address based on the cpuid available in the efuse
block: Use the first 6 byte of the cpuid's SHA256 hash and set the
locally administered bits. Also ensure that the multicast bit is
cleared.

The MAC address is only generated and set if there is no ethaddr
present in the saved environment.

This is based off of Klaus Goger's work in 8adc9d

Signed-off-by: Rohan Garg <rohan.garg@collabora.com>
Reviewed-by: Kever Yang <kever.yang@rock-chips.com>

arch/arm/include/asm/arch-rockchip/misc.h

@@ -0,0 +1,13 @@
+/* SPDX-License-Identifier: GPL-2.0+ */
+/*
+ * RK3399: Architecture common definitions
+ *
+ * Copyright (C) 2019 Collabora Inc - https://www.collabora.com/
+ *      Rohan Garg <rohan.garg@collabora.com>
+ */
+
+int rockchip_cpuid_from_efuse(const u32 cpuid_offset,
+			      const u32 cpuid_length,
+			      u8 *cpuid);
+int rockchip_cpuid_set(const u8 *cpuid, const u32 cpuid_length);
+int rockchip_setup_macaddr(void);

arch/arm/mach-rockchip/Makefile

@@ -25,6 +25,10 @@ endif
 
 obj-$(CONFIG_$(SPL_TPL_)RAM) += sdram_common.o
 
+ifdef CONFIG_MISC_INIT_R
+obj-y += misc.o
+endif
+
 obj-$(CONFIG_ROCKCHIP_RK3036) += rk3036/
 obj-$(CONFIG_ROCKCHIP_RK3128) += rk3128/
 ifndef CONFIG_TPL_BUILD

arch/arm/mach-rockchip/board.c

@@ -11,6 +11,7 @@
 #include <asm/arch-rockchip/boot_mode.h>
 #include <asm/arch-rockchip/clock.h>
 #include <asm/arch-rockchip/periph.h>
+#include <asm/arch-rockchip/misc.h>
 #include <power/regulator.h>
 
 DECLARE_GLOBAL_DATA_PTR;
@@ -102,3 +103,25 @@ int fastboot_set_reboot_flag(void)
 	return 0;
 }
 #endif
+
+#ifdef CONFIG_MISC_INIT_R
+__weak int misc_init_r(void)
+{
+	const u32 cpuid_offset = 0x7;
+	const u32 cpuid_length = 0x10;
+	u8 cpuid[cpuid_length];
+	int ret;
+
+	ret = rockchip_cpuid_from_efuse(cpuid_offset, cpuid_length, cpuid);
+	if (ret)
+		return ret;
+
+	ret = rockchip_cpuid_set(cpuid, cpuid_length);
+	if (ret)
+		return ret;
+
+	ret = rockchip_setup_macaddr();
+
+	return ret;
+}
+#endif

arch/arm/mach-rockchip/misc.c

@@ -0,0 +1,114 @@
+/* SPDX-License-Identifier: GPL-2.0+ */
+/*
+ * RK3399: Architecture common definitions
+ *
+ * Copyright (C) 2019 Collabora Inc - https://www.collabora.com/
+ *      Rohan Garg <rohan.garg@collabora.com>
+ *
+ * Based on puma-rk3399.c:
+ *      (C) Copyright 2017 Theobroma Systems Design und Consulting GmbH
+ */
+
+#include <common.h>
+#include <env.h>
+#include <dm.h>
+#include <dm/uclass-internal.h>
+#include <misc.h>
+#include <u-boot/sha256.h>
+
+#include <asm/arch-rockchip/misc.h>
+
+int rockchip_setup_macaddr(void)
+{
+#if CONFIG_IS_ENABLED(CMD_NET)
+	int ret;
+	const char *cpuid = env_get("cpuid#");
+	u8 hash[SHA256_SUM_LEN];
+	int size = sizeof(hash);
+	u8 mac_addr[6];
+
+	/* Only generate a MAC address, if none is set in the environment */
+	if (env_get("ethaddr"))
+		return -1;
+
+	if (!cpuid) {
+		debug("%s: could not retrieve 'cpuid#'\n", __func__);
+		return -1;
+	}
+
+	ret = hash_block("sha256", (void *)cpuid, strlen(cpuid), hash, &size);
+	if (ret) {
+		debug("%s: failed to calculate SHA256\n", __func__);
+		return -1;
+	}
+
+	/* Copy 6 bytes of the hash to base the MAC address on */
+	memcpy(mac_addr, hash, 6);
+
+	/* Make this a valid MAC address and set it */
+	mac_addr[0] &= 0xfe;  /* clear multicast bit */
+	mac_addr[0] |= 0x02;  /* set local assignment bit (IEEE802) */
+	eth_env_set_enetaddr("ethaddr", mac_addr);
+#endif
+	return 0;
+}
+
+int rockchip_cpuid_from_efuse(const u32 cpuid_offset,
+			      const u32 cpuid_length,
+			      u8 *cpuid)
+{
+#if CONFIG_IS_ENABLED(ROCKCHIP_EFUSE)
+	struct udevice *dev;
+	int ret;
+
+	/* retrieve the device */
+	ret = uclass_get_device_by_driver(UCLASS_MISC,
+					  DM_GET_DRIVER(rockchip_efuse), &dev);
+	if (ret) {
+		debug("%s: could not find efuse device\n", __func__);
+		return -1;
+	}
+
+	/* read the cpu_id range from the efuses */
+	ret = misc_read(dev, cpuid_offset, cpuid, sizeof(cpuid));
+	if (ret) {
+		debug("%s: reading cpuid from the efuses failed\n",
+		      __func__);
+		return -1;
+	}
+#endif
+	return 0;
+}
+
+int rockchip_cpuid_set(const u8 *cpuid, const u32 cpuid_length)
+{
+	u8 low[cpuid_length / 2], high[cpuid_length / 2];
+	char cpuid_str[cpuid_length * 2 + 1];
+	u64 serialno;
+	char serialno_str[17];
+	int i;
+
+	memset(cpuid_str, 0, sizeof(cpuid_str));
+	for (i = 0; i < 16; i++)
+		sprintf(&cpuid_str[i * 2], "%02x", cpuid[i]);
+
+	debug("cpuid: %s\n", cpuid_str);
+
+	/*
+	 * Mix the cpuid bytes using the same rules as in
+	 *   ${linux}/drivers/soc/rockchip/rockchip-cpuinfo.c
+	 */
+	for (i = 0; i < 8; i++) {
+		low[i] = cpuid[1 + (i << 1)];
+		high[i] = cpuid[i << 1];
+	}
+
+	serialno = crc32_no_comp(0, low, 8);
+	serialno |= (u64)crc32_no_comp(serialno, high, 8) << 32;
+	snprintf(serialno_str, sizeof(serialno_str), "%016llx", serialno);
+
+	env_set("cpuid#", cpuid_str);
+	env_set("serial#", serialno_str);
+
+	return 0;
+}