[PATCH 1/2] arm64: imx8mp: Read MAC address from M24C32-D write-lockable page on DH i.MX8MP DHCOM if available

[Marek Vasut]

On 10/10/24 3:23 PM, Christoph Niedermaier wrote:
> The i.MX8M Plus DHCOM currently supports parsing ethernet MAC address
> from multiple sources in the following priority order:
> 
> 1) U-Boot environment 'ethaddr'/'eth1addr' environment variable
> 2) SoC OTP fuses
> 3) On-SoM EEPROM
> 
> The new i.MX8M Plus DHCOM rev.200 is populated with M24C32-D EEPROM
> which contains additional write-lockable page, which can also be
> populated with a structure containing ethernet MAC address.
> 
> Add support for parsing the content of this new write-lockable page
> and place it between 2) and 3) on the priority list. The new entry is
> 2.5) On-SoM EEPROM write-lockable page
> 
> Because the write-lockable page is not present on rev.100 i.MX8MP DHCOM
> SoM, test whether EEPROM ID page exists in DT and whether it is enabled
> first. If so, read the entire ID page out, validate it, and determine
> whether EEPROM MAC address is populated in it in DH specific format. If
> so, use the MAC address. There may be multiple EEPROMs with an ID page
> on this platform, always use the first one.
> 
> Signed-off-by: Christoph Niedermaier <cniedermaier at dh-electronics.com>
> ---
> Cc: "NXP i.MX U-Boot Team" <uboot-imx at nxp.com>
> Cc: Marek Vasut <marex at denx.de>
> Cc: Fabio Estevam <festevam at gmail.com>
> Cc: Stefano Babic <sbabic at denx.de>
> Cc: Tom Rini <trini at konsulko.com>
> Cc: u-boot at dh-electronics.com
> ---
>   board/dhelectronics/common/dh_common.c        | 113 ++++++++++++++++++
>   board/dhelectronics/common/dh_common.h        |  23 ++++
>   .../dh_imx8mp/imx8mp_dhcom_pdk2.c             |   6 +
>   3 files changed, 142 insertions(+)
> 
> diff --git a/board/dhelectronics/common/dh_common.c b/board/dhelectronics/common/dh_common.c
> index 32c50b4f0f..8ea70fc984 100644
> --- a/board/dhelectronics/common/dh_common.c
> +++ b/board/dhelectronics/common/dh_common.c
> @@ -7,9 +7,22 @@
>   #include <dm.h>
>   #include <i2c_eeprom.h>
>   #include <net.h>
> +#include <u-boot/crc.h>
>   
>   #include "dh_common.h"
>   
> +struct eeprom_id_page {
> +	u8	id[3];		/* Identifier 'D', 'H', 'E' - 'D' is at index 0 */
> +	u8	version;	/* 0x10 -- Version 1.0 */
> +	u8	data_crc16[2];	/* [1] is MSbyte */
> +	u8	header_crc8;
> +	u8	mac0[6];
> +	u8	mac1[6];
> +	u8	item_prefix;	/* H/F is coded in MSbits, Vendor coding starts at LSbits */
> +	u8	item_num[3];	/* [2] is MSbyte */
> +	u8	serial[9];	/* [8] is MSbyte */
> +} __packed;

Is __packed needed ?

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