i2c on RPI-B not working

[Winston Smith]

On Wed, Apr 30, 2014 at 8:13 PM, Ian Lepore <ian at freebsd.org> wrote:
> The i2c eeproms, on the other hand, should just work.  Add 'device icee'
> to the kernel config, and in the dts file make an icee entry that's a
> child of the i2c controller entry.  Something like this (this is for
> wandboard)...
>
>                 i2c at 021a4000
>                 {
>                         status = "okay";
>                         icee at a0 {
>                                 compatible = "atmel,24c256";
>                                 reg = <0xa0>;
>                                 status = "okay";
>                         };
>                 };
>
> You'll end up with a /dev/icee0 device which you can read and write and
> seek and so on.  Note that the device will show up even if the hardware
> isn't there or isn't responding, there's no actual probe for hardware.
> If you do "dd /dev/icee0 | hd" and it comes up all-bits-one that's
> usually a sign that there's no hardware (but it could also be a brand
> new eeprom with nothing written to it).

Is there an equivalent for an RTC?

I know Linux will detect a DS1307 on the I2C bus and map it to
/dev/rtcN from which the system can use the time?

Thanks!