[U-Boot-Users] [patch] add support for "eeprom info"

Wolfgang Denk wd at denx.de
Wed Jan 23 22:06:01 CET 2008


In message <200801231113.38864.vapier at gentoo.org> you wrote:
> This patch adds a new sub command to eeprom called "info".  This allows eeprom
> driver writers to implement a way of querying the device.  For example, SPI
> flashes have status commands, jedec ids, part ids, and other fun stuff.  It's
> useful to be able to quickly probe this data (so you know things are detected
> properly and all that jazz).

How is this suppoesed to work on the "normal" EEPROm devices which are
typically attached to the I2C bus?

> I made the function weak so that people aren't required to implement this
> function (mostly so that it does not break all the SPI drivers out there right
> now).

... and I2C.

> +extern int  eeprom_info (void) __attribute__((weak));
>  #if defined(CFG_EEPROM_WREN)
>  extern int eeprom_write_enable (unsigned dev_addr, int state);
>  #endif
> @@ -104,7 +105,8 @@ int do_eeprom ( cmd_tbl_t * cmdtp, int flag, int argc, char *argv[])
>  
>  			puts ("done\n");
>  			return rcode;
> -		}
> +		} else if (argc == 2 && eeprom_info && strcmp (argv[1], "info") == 0)
> +			return eeprom_info ();

... && eeprom_info && ...?

Does that mean that a weak function resolves to a NULL pointer? Is
this guaranteed?

Best regards,

Wolfgang Denk

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