Re: Fwd: [linux-usb-devel] USB IR receivers and evdev

[<li...@ba...>]

Hi!

Jon Smirl "jon...@gm..." wrote:
[...]
>> btw, is there any reason why those drivers are implemented as kernel
>> modules? Couldn't lircd just use libusb and talk directly to the
>> devices instead?

> This is a very good question. It's not like LIRC is high speed.
> A big reason to be in the kernel is to manipulate device register with
> root priv, but these drivers don't need to do that.

Driver deveopment started when libusb was not stable/mature enough to rely on it. Later nobody really cared to convert the drivers to userspace except for the atiusb code, where also a userspace driver is available, but it does not support all the receivers that the kernel module supports.

One reason I would like to keep the drivers as kernel modules is that you can use tools like mode2 or xmode2 to easily test them.

> USB devices have libusb
> parallel and serial can just open the devices

The parallel and serial kernel modules need to implement an interrupt handler. You cannot use the standard devices.

> how about GPIO and anything else weird?

I don't know about GPIO, but for the I2C driver a userspace driver also is available, but I did not have time to integrate it into the code base yet.

Christoph