Including ds133x driver on RPI2 hangs kernel

[Tom Sparks]

I recently purchased some i2c RTCs for my RPI2, so in building a kernel to
support it I discovered that just including the driver hangs the kernel on
boot.

It doesn't matter if the rtc is connected or not, the kernel just fails to
complete the boot process.

When the driver isn't in the kernel, probing the i2c bus doesn't show any
devices anyways so not sure if this is an i2c problem on the RPI2 or if its
just a general problem with this driver.

I'm happy to test patches/etc.

-- 
Tom Sparks
Systems Engineer