From: Greg KH <gregkh@suse.de>
To: Raju Rameshwar Uprade <rajsingh@ncra.tifr.res.in>
Cc: linux-kernel@vger.kernel.org, linux-usb@vger.kernel.org
Subject: Re: Regarding USB-to-serial device driver
Date: Wed, 22 Sep 2010 07:56:07 -0700 [thread overview]
Message-ID: <20100922145607.GB26309@suse.de> (raw)
In-Reply-To: <20100922052107.M44650@admin-gateway.ncra.tifr.res.in>
On Wed, Sep 22, 2010 at 11:02:46AM +0530, Raju Rameshwar Uprade wrote:
>
>
> Greg,
> I am facing some problem in data copying.
> I am having a const unsigned char *buf which contains 02 08 00 00 00 00 00 00 f8.
> which is copied in port->write_urb->transfer_buffer and sent on ttyUSB0 using
> usb_submit_urb(port->write_urb, GFP_ATOMIC).
For what driver?
> But I want to send the data bytes is a particular fashion.
>
> 1. I want to Add Mark parity.
That's a control signal and is independant of the data payload, right?
> 2. Send the data byte 02 ( Address of a device )
That means you need to modify the data. Why not do that in userspace?
> 3. Add Space parity .
Again, control signal.
> 4. send the data byte 08 00 00 00 00 00 00 f8 ( Null cmd + check sum )
Should be fine.
> Kindly help me.I am facing the problem in separating the data bytes so
> that I can send the data bytes separately using usb_submit_urb.
It all depends on the driver you are using. Why not do all of this from
userspace? That way it works on any device you are talking to.
good luck,
greg k-h
next prev parent reply other threads:[~2010-09-22 15:06 UTC|newest]
Thread overview: 19+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-09-13 9:17 Regarding USB-to-Serial device driver Raju Rameshwar Uprade
2010-09-13 13:56 ` Alan Stern
2010-09-13 15:48 ` Greg KH
2010-09-14 6:11 ` Raju Rameshwar Uprade
2010-09-14 13:19 ` Greg KH
2010-09-22 5:32 ` Regarding USB-to-serial " Raju Rameshwar Uprade
2010-09-22 14:56 ` Greg KH [this message]
2010-09-23 10:15 ` Raju Rameshwar Uprade
2010-09-23 14:02 ` Greg KH
2010-09-28 9:21 ` Raju Rameshwar Uprade
2010-09-28 11:30 ` Greg KH
2010-09-28 11:56 ` Raju Rameshwar Uprade
2010-09-28 12:07 ` Greg KH
2010-10-04 4:33 ` Raju Rameshwar Uprade
2010-10-05 11:03 ` pl2303_ttyUSB0 userspace application not able to control RTS line Raju Rameshwar Uprade
2010-10-05 13:33 ` Greg KH
2010-10-06 4:14 ` Raju Rameshwar Uprade
2010-10-06 4:30 ` Greg Oliver
2010-10-06 5:01 ` Raju Rameshwar Uprade
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