[PATCH] i2c: Make I2C ID tables non-mandatory for DT'ed and/or ACPI'ed devices

Linus Walleij linus.walleij at linaro.org
Thu Jun 12 00:55:21 PDT 2014

On Wed, Jun 4, 2014 at 8:09 AM, Michael Lawnick <ml.lawnick at gmx.de> wrote:
> Am 03.06.2014 13:18, schrieb Linus Walleij:
>> On Mon, Jun 2, 2014 at 4:29 PM, Michael Lawnick <ml.lawnick at gmx.de> wrote:
>>> Am 02.06.2014 14:16, schrieb Linus Walleij:
>>>> Is this really so useful on embedded systems?
>>>> I was under the impression that this method was something used
>>>> on say PC desktops with temperature monitors and EEPROMs
>>>> on some I2C link on the PCB, usage entirely optional and fun
>>>> for userspace hacks.
>>> We use it for dynamic instantiating whole subsystems with multiplexers,
>>> sensors, controllers in an embedded system. The device list is taken from
>>> an
>>> I2C eeprom which gets read on hotplug.
>> Does this mean that you have stored the names (strings) that are used
>> by the Linux kernel for identifying the devices into your EEPROM?
>> That means that you have made the kernel-internal device driver names
>> an ABI which is unfortunate :-/
>> This is one of the reasons to why we insist on device tree: OS neutral
>> hardware description.
> The eeprom contains a device tree that is dynamically merged.

That is a kind of way of saying "yes we made the kernel-internal
driver named an ABI" I guess?

Linus Walleij

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