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Re: use ttyS1 as normal serial port on devboard82?




----- Original Message ----- 
From: "Phil Sutter" <phil@xxxxxxx.com>
To: <dev-etrax@xxxxxxx.com>
Sent: Saturday, October 04, 2003 9:30 PM
Subject: Re: use ttyS1 as normal serial port on devboard82?


> Hi,
>
> I am developing software for the the AXIS 82 board where the following
> interfaces will be used concurrently:
> ttyS0
> ttyS1
> ttyS2
> ttyS3
> The USB port
> The Primary Ethernet port
>
> I am trying to understand if there are any more shared resources, such
> as the DMA channels shared between COM3 and USB, that I must be

I prefer saying ser1/ttyS1 and USB - the COMx could be confusing.

> concerned with. If there are other shared resources that would limit
> concurrent use, are there configuration options or newer drivers that
> would allow me to work around any limitations?

Hi,
I just took a new look at:
http://developer.axis.com/doc/hardware/etrax100lx/des_ref/ET100LX_20_Electrical_Information_021107.pdf

Som of the USB port p1 pins are multiplexed with ser1 so both the DMA
channels and the pins
are shared between them. But on devboard 82, USB p1 is used for the second
Ethernet interface
so I think you should be fine if you only use USB p2 and interrupt driven
serial communication
is ok for ttyS1. How high baudrate do you need?



> Thanks,
>
> Phil Sutter

I'm hoping that a new developer board release will include the appropriate
patch to get the
new serial driver out to the masses :-)

Best regards
/Johan


> On Tue, 2003-09-30 at 10:50, Tomaz Frelih wrote:
> > Hi Johan,
> >
> > This is just what we need - interrupt driven serial drivers without
using DMA,
> > hopefully also LPT drivers in the same way. Please publish them or send
them
> > asap, we just came to this problem.
> >
> > Thx
> > Tomaz
> >
> > johan.adolfsson@xxxxxxx.com wrote:
> > >
> > > ----- Original Message -----
> > > From: "Henrik J├Ânsson" <henke@xxxxxxx.se>
> > > To: <dev-etrax@xxxxxxx.com>
> > > Sent: Monday, September 29, 2003 2:13 PM
> > > Subject: use ttyS1 as normal serial port on devboard82?
> > >
> > > > Is it possible to use ttyS1 (X25 pin header) as a regular serial
port? We
> > > > have enabled it in the kernel:
> > > >
> > > > [*]   Serial port 1 enabled
> > > > (No_DTR_RI_DSR_CD) Ser1 DTR, RI, DSR and CD assignment
> > > >
> > > > Correct? Should DTR_RI_DSR_CD be enabled? With these settings the
devboard
> > > > crashes when we try "echo HEJ > /dev/ttyS1".
> > > >
> > > > dmesg shows:
> > > > ttyS0 at 0xb0000060 is a builtin UART with DMA
> > > > ttyS1 at 0xb0000068 is a builtin UART with DMA
> > > > ttyS2 at 0xb0000070 is a builtin UART with DMA
> > > >
> > > > We know it's 3.3v levels so we have to use a level-shifter to get
standard
> > > > RS232 voltage.
> > > >
> > > > We are already using ttyS0 and ttyS2 so it would be great if tou
told us
> > > > it's possible to use ttyS1 as a third serial port!
> > > >
> > > > Regards
> > > > Henke
> > >
> > > Shouldn't be any problem, but ser1 (ttyS1) uses same DMA channels as
USB,
> > > so you can't use them at the same time.
> > > Latest version of the serial driver supports using interrupt driven
transfer
> > > without DMA - I don't think we have published that yet though.
> > >
> > > /Johan
>
>
>
>
>