[U-Boot] [U-Boot, PATCHv1, 1/3] net: Add ability to set MAC address via EEPROM to Kconfig

[Hans de Goede]

Hi Olliver and Joe,

On 11/30/2015 05:50 PM, Oliver Schinagl wrote:
> From: Olliver Schinagl <o.schinagl at ultimaker.com>
>
> This patch allows Kconfig to enable and set parameters to make it
> possible to read the MAC address from an EEPROM. This patch only sets up
> some environment variables, it is up to the specific boards to actually
> use these defines.
>
> Besides the various tuneables as to how to access the eeprom (bus,
> address, addressing mode/length, 2 configurable that are EEPROM generic
> (e.g. SPI or some other form of access) which are:
>
> NET_ETHADDR_EEPROM_OFFSET, indicating where in the EEPROM the start of
> the MAC address is. The default is 8 allowing for 8 bytes before the MAC
> for other purposes (header MAGIC for example).
>
> NET_ETHADDR_EEPROM_CRC8, indicating the MAC is appended with a CRC8-CCIT
> checksum that should be verified.
>
> Currently only I2C eeproms have been tested and thus only those options
> are available, but shouldn't be a limit. NET_ETHADDR_EEPROM_SPI can be
> just as created.
>
> Signed-off-by: Olliver Schinagl <o.schinagl at ultimaker.com>

Thanks, from a sunxi pov this and the other 2 patches look good.

Joe can we have your ack for this one please and/or can you merge this
one through your tree? Either way I will take care of the other 2
patches in this set.

 From my pov this is fine as v2016.01 material, but if you would
rather postpone this to v2016.04 that is fine too.

Thanks & Regards,

Hans


> ---
>   doc/README.enetaddr | 36 +++++++++++++++++++++++++++++++++
>   net/Kconfig         | 58 +++++++++++++++++++++++++++++++++++++++++++++++++++++
>   2 files changed, 94 insertions(+)
>
> diff --git a/doc/README.enetaddr b/doc/README.enetaddr
> index 50e4899..c53b455 100644
> --- a/doc/README.enetaddr
> +++ b/doc/README.enetaddr
> @@ -47,6 +47,42 @@ Correct flow of setting up the MAC address (summarized):
>   Previous behavior had the MAC address always being programmed into hardware
>   in the device's init() function.
>
> +--------
> + EEPROM
> +--------
> +
> +When there is an EEPROM available on a board, but the EEPROM is not large enough
> +to store the whole environment, it may be desired to store a MAC address in the
> +onboard EEPROM. Using CONFIG_NET_ETHADDR_EEPROM enables this feature. Depending
> +on the board, the EEPROM may be connected on various methods, but currently,
> +only the I2C bus is available via CONFIG_NET_ETHADDR_EEPROM_I2C.
> +CONFIG_NET_ETHADDR_EEPROM_I2C_BUS I2C bus on which the eeprom is present and
> +CONFIG_NET_ETHADDR_EEPROM_I2C_ADDR set the address of the EEPROM, which
> +defaults to the very common 0x50. Small size EEPROM's generally use single byte
> +addressing but larger EEPROM's may use double byte addressing, which can be
> +configured using CONFIG_NET_ETHADDR_EEPROM_ADDRLEN.
> +
> +Within the EEPROM, the MAC address can be stored on any arbitrary offset,
> +CONFIG_NET_ETHADDR_EEPROM_OFFSET sets this to 8 as a default however, allowing
> +the first 8 bytes to be used for some header magic for example.
> +
> +After the 6 bytes used for the MAC address, there is an 8 byte field to indicate
> +the ID of the network interface this MAC address is for. 0xff here means 'for
> +the first available interface' and 0x00 means the first network interface, 0x01
> +the second, etc. It is up to the platform however to enforce this.
> +
> +Appending the 6 MAC bytes and the 7th interface byte is a CRC8 byte over the
> +previous 7 bytes. Whether to check this CRC8 or not is dependent on
> +CONFIG_NET_ETHADDR_EEPROM_CRC8.
> +
> +Layout example:
> +
> +00000000  21 4d 61 67 69 63 2e 21  01 23 45 67 89 ab ff c0  |!Magic.!.#Eg....|
> +
> +where the Header magic (!Magic.!) is spread over the first 8 bytes, and the MAC
> +address '01-23-45-67-89-ab' for the first interface (0xff) with the CRC8
> +checksum 0xc0.
> +
>   -------
>    Usage
>   -------
> diff --git a/net/Kconfig b/net/Kconfig
> index a44a783..aced51e 100644
> --- a/net/Kconfig
> +++ b/net/Kconfig
> @@ -7,6 +7,64 @@ menuconfig NET
>
>   if NET
>
> +config NET_ETHADDR_EEPROM
> +	bool "Get ethaddr from eeprom"
> +	help
> +	  Selecting this will try to get the Ethernet address from an onboard
> +	  EEPROM and set into the environment if and only if the environment
> +	  does currently not already hold a MAC address. For more information
> +	  see doc/README.enetaddr.
> +
> +config NET_ETHADDR_EEPROM_I2C
> +	depends on NET_ETHADDR_EEPROM
> +	bool "EEPROM on I2C bus"
> +	help
> +	  This switch enables checks for an EEPROM on the I2C bus. Naturally
> +	  this will only work if there is an actual EEPROM connected on the
> +	  I2C bus and the bus and device are properly configured via the
> +	  options below.
> +
> +config NET_ETHADDR_EEPROM_I2C_BUS
> +	depends on NET_ETHADDR_EEPROM_I2C
> +	int "I2C bus"
> +	default 0
> +	help
> +	  Select the bus on which the EEPROM is present, defaults to bus 0.
> +
> +config NET_ETHADDR_EEPROM_I2C_ADDR
> +	depends on NET_ETHADDR_EEPROM_I2C
> +	hex "eeprom address"
> +	default 0x50
> +	help
> +	  Select the address of the eeprom, defaults to address 0x50.
> +
> +config NET_ETHADDR_EEPROM_I2C_ADDRLEN
> +	depends on NET_ETHADDR_EEPROM_I2C
> +	int "eeprom address length"
> +	default 1
> +	help
> +	  Number of bytes to be used for the I2C address length. Typically 1,
> +	  2 for large memories, 0 for register type devices with only one
> +	  register.
> +
> +config NET_ETHADDR_EEPROM_OFFSET
> +	depends on NET_ETHADDR_EEPROM
> +	int "EEPROM offset"
> +	default 8
> +	help
> +	  Select the byte offset of the MAC address within the page,
> +	  defaults to byte 8.
> +
> +config NET_ETHADDR_EEPROM_CRC8
> +	depends on NET_ETHADDR_EEPROM
> +	bool "Check CRC8 of MAC"
> +	default y
> +	help
> +	  Optionally, it is possible to run a CRC-8-CCITT check on the MAC
> +	  address. To do so, the MAC address is stored with a CRC8 byte append.
> +	  This option enables the CRC check of the MAC address against the CRC
> +	  byte.
> +
>   config NET_RANDOM_ETHADDR
>   	bool "Random ethaddr if unset"
>   	select LIB_RAND
>