Re: [patch 0/8] Nesting class_device patches that actually work

Vojtech Pavlik
2005-10-17T10:02:26Z

On Fri, Oct 14, 2005 at 02:14:23PM +0200, Kay Sievers wrote:

> Sorry, my previous drawing wasn't correct for the input devices.
>
> Here is a new picture of the:
> - all classes are unique and flat and will stay the same,
> even when the hierarchy of the devices changes
> - all hierarchy is _only_ in /sys/devices
> - virtual and physical devices are both in /sys/devices
> proposal.

I like the layout.

I'm not completely sure whether mouse0 and event0 are the same class,
because they have different APIs and protocols. And I believe that class
is exactly that - a collection of devices where you can use the same API
to access them. A possibility would be to do it like this:

> /sys
> |-- class
> | |-- mouse
> | | |-- mice -> ../../devices/mice
> | | |-- mouse0 -> ../../devices/platform/i8042/serio0/input0/mouse0
> | |---event
> | | `-- event0 -> ../../devices/platform/i8042/serio0/input0/event0
> | |-- input
> | | `-- input0 -> ../../devices/platform/i8042/serio0/input0
> | `-- tty
> | `-- console -> ../../devices/console

It might be too much work to create a new class in each of the
handlers, it'd be similar to harddrives and partititions having
different classes.

> /sys
> |-- class
> | |-- input
> | | |-- mice -> ../../devices/mice
> | | |-- mouse0 -> ../../devices/platform/i8042/serio0/input0/mouse0
> | | `-- event0 -> ../../devices/platform/i8042/serio0/input0/event0
> | |-- input_device
> | | `-- input0 -> ../../devices/platform/i8042/serio0/input0
> |
> |-- devices
> | |-- platform
> | | `-- i8042
> | | `-- serio0
> | | `-- input0
> | | |-- event0
> | | | `-- dev
> | | |-- mouse0
> | | | `-- dev
> | | |-- bind_mode
> | | |-- description
> | | |-- id
> | | | |-- extra
> | | | |-- id
> | | | |-- proto
> | | | `-- type
> | | |-- modalias
> | | |-- protocol
> | | |-- rate
> | | |-- resetafter
> | | `-- resolution
> | |-- mice
> | | `-- dev

Having 'mice' at top level is not very nice. It's a logical consequence
of the system, and as such probably correct, though.

--
Vojtech Pavlik
SuSE Labs, SuSE CR