Re: Dealing with optional i2c devices in a devicetree

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Am 08.06.2015 um 08:01 schrieb Chris Packham:

Hi folks,

> Sounds like my best bet is to mark the nodes as disabled in the
> dts and have my bootloader update them on the way through.

In case your bootloader can take that decision (eg. if the device
is present at boot time, and the bootloader has the proper probing
logic or simply knows the device has to be there), that would be
an pretty easy way.


But let me add another usecase, which might be a bit more tricky:

Let's assume we can plug in some more complex device, which consists
of several (pretty standard) subdevices, behind certain bus'es (maybe
it's attached via USB, and somewhere behind are some I2C bus'es with
regulators, pwm-generators, etc).

Let's further assume, we already got some DTS or some piece of memory
with an DTB subtree for that device (eg. some simple bulk endpoint that
just gives back a bunch of bytes with the DTB).

Now, when the device is plugged in, I'd like to get that piece of DTB
loaded and the corresponding drivers initialized. And, of course, when
it's plugged-out, everything should be shut down cleanly.

How could we achieve that ?


--mtx
--
Enrico Weigelt, metux IT consult
+49-151-27565287
MELAG Medizintechnik oHG Sitz Berlin Registergericht AG Charlottenburg HRA 21333 B

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