lcd4linux-users

[lcd4linux] uClinux patch.

[Hans E. <ha...@ru...>]

Hi lcd4linux users and developers.

Im involved in a project running related to running systems onuClinux on 
Blackfin. Recently i got the task to implement the hardware and software 
needed for a HD44780 LCD via I2C for the blackfin. Doing that i got the ide 
to try to port either lcdproc or lcd4linux. Lcdproc failed on some shared 
library build(may persue that later) but i made a successful build of 
lcd4linux and i have also made a uClinux patch for HD44780 over i2c(via 
pfc8574). Has this been done? Tried to search for any other LCD-uClinux 
projects but with no luck. Instructions on how to set it up, and also notes 
on the patch at:

http://www.vpx.nu/dokuwiki/doku.php?id=displays

Also, note that i did(in function rep_nop for the delays)
-    __asm__ __volatile__("rep; nop");
+    __asm__ __volatile__("nop");

since i think rep is IA32 specific. Dont know if this is a good final solution 
for all platforms.

Im sure some developer can use the patch and incorporate it to a future 
release in a sweet mannner, a configure switch of --with-uclinux would be 
nice:). Im not a make guru so i did not do it so fancy. Hope anyone else can 
try it out on their embedded system.

regards

Hans Eklund
Developer
www.rubico.se
blackfin.uclinux.org

Re: [lcd4linux] uClinux patch.

[Michael R. <re...@eu...>]

Hi Hans,

> Im involved in a project running related to running systems onuClinux on 
> Blackfin. Recently i got the task to implement the hardware and software 
> needed for a HD44780 LCD via I2C for the blackfin. Doing that i got the ide 
> to try to port either lcdproc or lcd4linux. Lcdproc failed on some shared 
> library build(may persue that later) but i made a successful build of 
> lcd4linux and i have also made a uClinux patch for HD44780 over i2c(via 
> pfc8574). Has this been done? Tried to search for any other LCD-uClinux 
> projects but with no luck. Instructions on how to set it up, and also notes 
> on the patch at:
> 
> http://www.vpx.nu/dokuwiki/doku.php?id=displays

Look nice!

> Also, note that i did(in function rep_nop for the delays)
> -    __asm__ __volatile__("rep; nop");
> +    __asm__ __volatile__("nop");
> 
> since i think rep is IA32 specific. Dont know if this is a good final solution 
> for all platforms.
This has already been fixed in CVS/SVN.

> Im sure some developer can use the patch and incorporate it to a future 
> release in a sweet mannner, a configure switch of --with-uclinux would be 
> nice:). Im not a make guru so i did not do it so fancy. Hope anyone else can 
> try it out on their embedded system.

I had a look at your patch. I can't accept it as it is, because it would
cause lots of problems with people needing the parpott driver :-(

But I got another idea: I will duplicate the HD44780 driver entry in
drivers.m4, providing kind of a "sub-driver" called "HD44780-I2C", which
 doesnt use parport at all.

Are you willing to do some testing? You would have to use the SVN version...

Another question: Why did you use vfork()? From what I've read in the
manpage, this is dangerous....


bye, Michael

-- 
Michael Reinelt <re...@eu...>
http://home.pages.at/reinelt
GPG-Key 0xDF13BA50
ICQ #288386781

Re: [lcd4linux] [Lcd4linux-devel] uClinux patch.

[Luis C. <lfc...@lf...>]

Luis Correia wrote:
> Michael Reinelt wrote:
>> Hi Hans,
>>
>>  
>>> Im involved in a project running related to running systems 
>>> onuClinux on Blackfin. Recently i got the task to implement the 
>>> hardware and software needed for a HD44780 LCD via I2C for the 
>>> blackfin. Doing that i got the ide to try to port either lcdproc or 
>>> lcd4linux. Lcdproc failed on some shared library build(may persue 
>>> that later) but i made a successful build of lcd4linux and i have 
>>> also made a uClinux patch for HD44780 over i2c(via pfc8574). Has 
>>> this been done? Tried to search for any other LCD-uClinux projects 
>>> but with no luck. Instructions on how to set it up, and also notes 
>>> on the patch at:
>>>
>>> http://www.vpx.nu/dokuwiki/doku.php?id=displays
>>>     
>>
>> Look nice!
>>
>>  
>>> Also, note that i did(in function rep_nop for the delays)
>>> -    __asm__ __volatile__("rep; nop");
>>> +    __asm__ __volatile__("nop");
>>>
>>> since i think rep is IA32 specific. Dont know if this is a good 
>>> final solution for all platforms.
>>>     
>> This has already been fixed in CVS/SVN.
>>
>>  
>>> Im sure some developer can use the patch and incorporate it to a 
>>> future release in a sweet mannner, a configure switch of 
>>> --with-uclinux would be nice:). Im not a make guru so i did not do 
>>> it so fancy. Hope anyone else can try it out on their embedded system.
>>>     
>>
>> I had a look at your patch. I can't accept it as it is, because it would
>> cause lots of problems with people needing the parpott driver :-(
>>
>> But I got another idea: I will duplicate the HD44780 driver entry in
>> drivers.m4, providing kind of a "sub-driver" called "HD44780-I2C", which
>>  doesnt use parport at all.
>>   
>
> I can help debugging this one, as I half wrote the first implementation.
>
> Have you checked the way we have done it?
>
>> Are you willing to do some testing? You would have to use the SVN 
>> version...
>>
>> Another question: Why did you use vfork()? From what I've read in the
>> manpage, this is dangerous....
>>
>>
>> bye, Michael
>>
>>   
>
> Luis
>
Sorry, the first one got caught in some spam filter, don't know why...



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Re: [lcd4linux] [Lcd4linux-devel] uClinux patch.

[Michael R. <re...@eu...>]

Hi Luis,

>> I can help debugging this one, as I half wrote the first implementation.
Great!

Did you already switch to SVN? :-)

>> Have you checked the way we have done it?
Sorry, I don't know what you mean... I thinke the OP's problem is that
he does not want any parport stuff get compiled/linked.


-- 
Michael Reinelt <re...@eu...>
http://home.pages.at/reinelt
GPG-Key 0xDF13BA50
ICQ #288386781

Re: [lcd4linux] [Lcd4linux-devel] uClinux patch.

[Luis C. <lfc...@lf...>]

Michael Reinelt wrote:
> Hi Luis,
>
>   
>>> I can help debugging this one, as I half wrote the first implementation.
>>>       
> Great!
>
> Did you already switch to SVN? :-)
>
>   
I did a test checkout yesterday, but no compile tests were done

>>> Have you checked the way we have done it?
>>>       
> Sorry, I don't know what you mean... I thinke the OP's problem is that
> he does not want any parport stuff get compiled/linked.
>
>   
I meant the way we talked to the PCF chip, and the question was meant 
for the uClinux developer, not you, sorry for the confusion.

I plan to put myself back into lcd4linux development, to finally finish 
the HD44780-I2C driver, if you split it into it's own file, it would 
surely make things better :)

Luis

p.s. no need to CC me



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