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

[Michal Simek]

On 8.11.2016 16:54, Olliver Schinagl wrote:
> 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);
> +}
> +

ok. I have briefly looked at the whole series and I think that this
should be done in the core because this should be shared across all
drivers.
Because what you have above make in general sense for every board which
contain mac address in eeprom.
That's why I would create

eeprom_read_rom_etheaddr() in core which will do stuff as you have above
and in driver we will simply assign it to read_rom_hwaddr in drivers or
by default for all with options to rewrite it.
This function will be empty when !NET_ETHADDR_EEPROM.

By this or similar way you open this to all ethernet drivers to read mac
just through enabling Kconfig.

IMHO doesn't make sense to c&p the same logic over all ethernet drivers.

Thanks,
Michal