[U-Boot] [PATCH 08/11] net: sunxi: Allow sunxi boards to set the MAC from an EEPROM

[Olliver Schinagl]

This patch uses the newly introduced Kconfig options to use the net_op
read_rom_hwaddr to retrieve the MAC from an EEPROM.
This will be especially useful for the Olimex OLinuXino series of sunxi
boards as they all have an 2k i2c eeprom chip.

The MAC address in the eeprom is ignored (if enabled) if the CRC8 check
fails.

This new functionality allows for querying multiple MAC addresses. The
first (supported) device being probed gets the first address, the second
the second etc. If a generated MAC address is desired, set it to all 0
(and if crc8 is configured also add that) for the adapter.

Signed-off-by: Olliver Schinagl <oliver at schinagl.nl>
---
 board/sunxi/Kconfig |  4 ++++
 board/sunxi/board.c | 39 ++++++++++++++++++++++++++++++++++++++-
 2 files changed, 42 insertions(+), 1 deletion(-)

diff --git a/board/sunxi/Kconfig b/board/sunxi/Kconfig
index e1d4ab1..6b8ac99 100644
--- a/board/sunxi/Kconfig
+++ b/board/sunxi/Kconfig
@@ -414,6 +414,7 @@ config I2C0_ENABLE
 
 config I2C1_ENABLE
 	bool "Enable I2C/TWI controller 1"
+	default y if (NET_ETHADDR_EEPROM_I2C_BUS = 1)
 	default n
 	select CMD_I2C
 	---help---
@@ -421,6 +422,7 @@ config I2C1_ENABLE
 
 config I2C2_ENABLE
 	bool "Enable I2C/TWI controller 2"
+	default y if NET_ETHADDR_EEPROM_I2C_BUS = 2
 	default n
 	select CMD_I2C
 	---help---
@@ -428,6 +430,7 @@ config I2C2_ENABLE
 
 if MACH_SUN6I || MACH_SUN7I
 config I2C3_ENABLE
+	default y if NET_ETHADDR_EEPROM_I2C_BUS = 3
 	bool "Enable I2C/TWI controller 3"
 	default n
 	select CMD_I2C
@@ -447,6 +450,7 @@ endif
 
 if MACH_SUN7I
 config I2C4_ENABLE
+	default y if NET_ETHADDR_EEPROM_I2C_BUS = 4
 	bool "Enable I2C/TWI controller 4"
 	default n
 	select CMD_I2C
diff --git a/board/sunxi/board.c b/board/sunxi/board.c
index 71124f4..f1e64cd 100644
--- a/board/sunxi/board.c
+++ b/board/sunxi/board.c
@@ -12,6 +12,7 @@
  */
 
 #include <common.h>
+#include <i2c.h>
 #include <mmc.h>
 #include <axp_pmic.h>
 #include <asm/arch/clock.h>
@@ -31,6 +32,7 @@
 #include <crc.h>
 #include <environment.h>
 #include <libfdt.h>
+#include <linux/crc8.h>
 #include <nand.h>
 #include <net.h>
 #include <sy8106a.h>
@@ -626,11 +628,46 @@ static void _sunxi_gen_sid_hwaddr(unsigned char *enetaddr, uint8_t cnt)
 	memcpy(enetaddr, mac_addr, ARP_HLEN);
 }
 
+static void _sunxi_read_rom_hwaddr(unsigned char *enetaddr, uint8_t cnt)
+{
+	uint8_t eeprom[ARP_HLEN + 1] = { 0x00 };
+#if defined(CONFIG_NET_ETHADDR_EEPROM) && defined(CONFIG_NET_ETHADDR_EEPROM_I2C)
+	int old_i2c_bus;
+
+	old_i2c_bus = i2c_get_bus_num();
+	if (old_i2c_bus != CONFIG_NET_ETHADDR_EEPROM_I2C_BUS)
+		i2c_set_bus_num(CONFIG_NET_ETHADDR_EEPROM_I2C_BUS);
+	/* Skip in blocks of 8 (ARP + CRC8 + pad), but read 7. */
+	if (i2c_read(CONFIG_NET_ETHADDR_EEPROM_I2C_ADDR,
+		     CONFIG_NET_ETHADDR_EEPROM_OFFSET + (cnt * (ARP_HLEN + 2)),
+		     CONFIG_NET_ETHADDR_EEPROM_I2C_ADDRLEN,
+		     eeprom, ARP_HLEN + 1)) {
+		i2c_set_bus_num(old_i2c_bus);
+		puts("Could not read the EEPROM; EEPROM missing?\n");
+		return;
+	}
+	i2c_set_bus_num(old_i2c_bus);
+#ifdef CONFIG_NET_ETHADDR_EEPROM_CRC8
+	if (crc8(0, eeprom, ARP_HLEN) != eeprom[ARP_HLEN]) {
+		puts("CRC error on MAC address from EEPROM.\n");
+		return;
+	}
+#endif
+#endif
+
+	memcpy(enetaddr, eeprom, ARP_HLEN);
+}
+
 static int sunxi_read_rom_hwaddr(unsigned char *enetaddr)
 {
 	static unsigned int cnt;
 
-	_sunxi_gen_sid_hwaddr(enetaddr, cnt);
+	_sunxi_read_rom_hwaddr(enetaddr, cnt);
+
+	if (is_zero_ethaddr(enetaddr)) {
+		_sunxi_gen_sid_hwaddr(enetaddr, cnt);
+		puts("Serial# based ");
+	}
 
 	/* First call, first stored MAC address, increase for next call */
 	cnt++;
-- 
2.10.2