Re: questions about undocumented USB drivers

["Jonathan A. Kollasch" <jakllsch%kollasch.net@localhost>]

On Fri, Jul 08, 2022 at 09:18:47AM +0000, nia wrote:
> I'd like to know more about these drivers so I can write man pages
> for them, so any input is welcome.
> 
 ~~~~~
 ~~~~~
> sys/dev/usb/slurm.c
> 
> 	This one caught my eye because it doesn't have the "u" prefix.
> 	Log message, from jakllsch@ in 2013:
> 	"Add slurm(4), a radio(4) driver for USB FM radio modules based
> 	on the Silicon Labs reference design."
> 	I can get a rough idea of the driver's capabilities by reading
> 	the code. It seems much better than udsbr(4), the only USB
> 	radio(4) driver we do document.

I'm somewhat of the belief that the 'u' prefix denotes a USB "class
device" driver; and there's no USB class number or specification for
these devices, and as such the 'u' prefix isn't strongly suggested.
Plus, that reasoning allowed me to make a reference to pop culture.

The hardware I developed against is an Instant FM Music, model RDX-155,
from ADS Tech.  I still have it around.

A slurm(4) page should reference uaudio(4), as there's always/often no
other way to get the audio signal out of the device.