> > > > I found Documentation/ioctl-numbers.txt for new-style ioctls.
> > > > Currently I'm using 'N' with a range of 20 to 3F.
> > > > Before a final release, I'll check if they're still unused.
> > > 
> > > Heh, good luck, I don't think I'll take a patch adding new ioctls
> > > without a _very_ good reason.
> > 
> > What about the ioctls to control the latency of the on-chip buffers?
> > They are very useful for performance tuning. IMHO there are enough
> > useful uses for the new ioctls.
> 
> For "normal" serial devices, or this odd bit controlled device?

The new ioctl handler is just for the ftdi_sio driver.

> > > Also, you'll need to make the necessary
> > > 64 bit thunking layer if somehow you convince me :)
> > 
> > I thought using the _IO macros should do it
> > or did I miss something?
> 
> No, those macros don't do it.  If you have a strong stomach, look at:
> arch/sparc64/kernel/ioctl32.c
> for just one of the arch specific files that you will have to modify.
> Make sure you get them all, or you will have some angry maintainers to
> deal with...

But this isn't necessary if the new handler
is inside the ftdi_sio driver, is it? :-)

> > > > [FTDI Bit Bang mode]
> > > But it isn't serial data, so you don't need the tty layer.  Why not just
> > > do it all though libusb/usbfs in userspace?
> > 
> > But you have to send the data using the serial way.
> > A userspace program using libusb would have to copy all the init
> > and data writing code of the kernel.
> 
> What init and data writing code?

Reseting the chip, calculating/setting the baud rate, writing data etc.

> > Also it would be better
> > if people could use a stock kernel instead of having to download
> > libusb and special software if they want to use the bitbang mode.
> 
> Heh, it's _much_ easier to use a userspace program using libusb than to
> tell someone to upgrade their kernel version.  Trust me on this one.

Well, as the "old" ftdi_sio driver had some bugs with BM type chips,
they have to upgrade their kernel anyway.

> > The bitbang mode just changes the final behavior of the chip,
> > all data transfer is done the same way.
> 
> But the end use of the device is then different, right?

Not really. For example I'll use it as a synchronous serial line
(using one output as clock line) on over 100+ machines
to flash an Atmel microcontroller.

Cheers,
Thomas



-------------------------------------------------------
This SF.net email is sponsored by: SlickEdit Inc. Develop an edge.
The most comprehensive and flexible code editor you can use.
Code faster. C/C++, C#, Java, HTML, XML, many more. FREE 30-Day Trial.
www.slickedit.com/sourceforge
_______________________________________________
[EMAIL PROTECTED]
To unsubscribe, use the last form field at:
https://lists.sourceforge.net/lists/listinfo/linux-usb-devel

Reply via email to