ioctl(TIOCMGET) on Lite5200

ioctl(TIOCMGET) on Lite5200

[saurosalomoni]

Hi there.

I'm having a problem with a specific argument of the
ioctl function, which is ioctl(TIOCMGET).
I wrote a simple routine which just reads or writes the
RTS pin.
It worked OK on my Red Hat 9, under x86, but when I try
to run it on a Lite5200 using denx kernel 2.4-25, it
keeps saying "TIOCMGET failed: Invalid argument" and
crashes out...
I think it could be due to some differences between the
two drivers, but I'm not sure about that. I wonder if
there's another argument that could provided me this
information, or if there's a way to ask for it
"manually" with ioctl...
Thanks in advance.
Here's a simple version of my code:

 int fd, status;
 fd = open("/dev/ttyS0", O_RDWR);
 if (ioctl(fd, TIOCMGET, &status) < 0)
   printf("TIOCMGET failed: %s\n", strerror(errno));
 else
   {...

 /* then, to check the status, i make this test */
 if (status & TIOCM_RTS)

 /* to set RTS */
 status &= ~TIOCM_RTS;
 ioctl(fd, TIOCMSET, &status);

 /* and to reset RTS */
 status |= TIOCM_RTS;
 ioctl(fd, TIOCMSET, &status);


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Re: ioctl(TIOCMGET) on Lite5200

[Wolfgang Denk]

In message <HZ0056$6237825DE310949AB818EA81D16B09F0@bol.com.br> you wrote:
>
> I'm having a problem with a specific argument of the
> ioctl function, which is ioctl(TIOCMGET).
> I wrote a simple routine which just reads or writes the
> RTS pin.
> It worked OK on my Red Hat 9, under x86, but when I try
> to run it on a Lite5200 using denx kernel 2.4-25, it
> keeps saying "TIOCMGET failed: Invalid argument" and

Well, that says it all: the TIOCMGET ioctl() is not available for the
5200's PSC uart driver.

Best regards,

Wolfgang Denk

--
Software Engineering:  Embedded and Realtime Systems,  Embedded Linux
Phone: (+49)-8142-4596-87  Fax: (+49)-8142-4596-88  Email: wd@denx.de
A right is not what someone gives you; it's what no one can take from
you.                                                   - Ramsey Clark

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Re: ioctl(TIOCMGET) on Lite5200

[saurosalomoni]

> In message
<HZ0056$6237825DE310949AB818EA81D16B09F0@bol.com.br> you
wrote:
> >
> > I'm having a problem with a specific argument of the
> > ioctl function, which is ioctl(TIOCMGET).
> > I wrote a simple routine which just reads or writes the
> > RTS pin.
> > It worked OK on my Red Hat 9, under x86, but when I try
> > to run it on a Lite5200 using denx kernel 2.4-25, it
> > keeps saying "TIOCMGET failed: Invalid argument" and
>
> Well, that says it all: the TIOCMGET ioctl() is not
available for the
> 5200's PSC uart driver.
>
> Best regards,
>
> Wolfgang Denk

So, if the 5200 series don't support TIOCMGET and
TIOCMSET ioctl() (nor TIOCMBIS and TIOCMBIC, I've just
tried them), what could I possibly use to get/set the
control pin RTS in my Lite5200?...
Is there any other system call or function that
accomplishes that?

Thank you very much.


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Re: ioctl(TIOCMGET) on Lite5200

[Wolfgang Denk]

In message <HZ1LA5$9EA97153A3F2D2EC1AD72AC1798B6528@bol.com.br> you wrote:
>
> So, if the 5200 series don't support TIOCMGET and
> TIOCMSET ioctl() (nor TIOCMBIS and TIOCMBIC, I've just
> tried them), what could I possibly use to get/set the
> control pin RTS in my Lite5200?...
> Is there any other system call or function that
> accomplishes that?

The current version of the 5200 PSC  UART  driver  does  not  support
hardware handshake, so there is no way to control the RTS pin. If you
really  must,  you  can  either extend the driver to support hardware
handshake, or you could simply write a small driver to  control  this
pin as GPIO.

Best regards,

Wolfgang Denk

--
Software Engineering:  Embedded and Realtime Systems,  Embedded Linux
Phone: (+49)-8142-4596-87  Fax: (+49)-8142-4596-88  Email: wd@denx.de
Imitation is the sincerest form of plagarism.

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