Hi Kaiwan,
Having a quick look over your code, I can see one issue that I think
would be making a big difference.
Your "gpio" pointer is declared at the start as "volatile unsigned
short *" but the offsets that you are adding to it to reach
each particular port are BYTE offsets. So for example if you
add PBDR_OFF (which is 0x04) to the gpio pointer, you will actually
be referencing 4 short integers past gpio or 8 bytes past it. (I
hope you understand my explanation)
Hopefully, that's the only problem.. I haven't done much assembler
for the arm, so I can help with the peek/poke code, other than
saying that you shouldn't really need to go to those lengths.. look
at the code that others have suggested, or at the example in the TS-
7200 manuals for the optional ADC which shows reading/writing to
registers.
Cheers
Phil
--- In Kaiwan N Billimoria <>
wrote:
> Hi All,
>
> Am attempting to write a user-space driver program to use the DIO
header
> facility on the TS-7200.
> I get access via mmap() to the gpio base addr (0x80840000), then
set
> (poke) the PxDDR register (where x is one of A-C, E-H) for output
> (setting some bit(s) high), then attempt to write (poke) the
> corresponding PxDR register. AFAIK that's the procedure to be
followed
> according to the EP9301 User Manual. Am I right until here?
>
> Well, it seems that no matter what GPIO DDR register i'm writing
to and
> what bit patter is being written, it's value (when peeked) is
0xff. ??
> For example, trying to use Port B, I write 0x04 to PBDDR, but on
peeking
> it's value is 0xff. So, measuring w/ a voltmeter on the DIO header
I can
> see that all relevant Port B lines are high.
> What I require is that my program can set the lines (DIO0 thru
DIO7)
> selectively.
>
> Of course this is all a moot point if this is not the "right" way
to do
> GPIO in the first place. Any inputs would be appreciated..
>
> (For those who want to see the source file i've currently written
(and
> got stuck on), pl find it here:
> http://www.designergraphix.com/kaiwan/projects/gpio/TS7200-
gpio.html ).
>
> Regards,
> Kaiwan.
------------------------ Yahoo! Groups Sponsor --------------------~-->
<font face=arial size=-1><a
href="http://us.ard.yahoo.com/SIG=12h67pmd9/M=362329.6886308.7839368.1510227/D=groups/S=1705005378:TM/Y=YAHOO/EXP=1124803129/A=2894321/R=0/SIG=11dvsfulr/*http://youthnoise.com/page.php?page_id=1992
">Fair play? Video games influencing politics. Click and talk back!</a>.</font>
--------------------------------------------------------------------~->
Yahoo! Groups Links
<*> To visit your group on the web, go to:
http://groups.yahoo.com/group/ts-7000/
<*> To unsubscribe from this group, send an email to:
<*> Your use of Yahoo! Groups is subject to:
http://docs.yahoo.com/info/terms/
|