DCMD_CHR_SERCTL

Synopsis:

#include <sys/dcmd_chr.h>

#define DCMD_CHR_SERCTL   __DIOT(_DCMD_CHR, 20, int)

Arguments to devctl():


Argument	Value
`filedes`	A file descriptor that you obtained by opening the device.
`dcmd`	DCMD_CHR_SERCTL
`dev_data_ptr`	A pointer to an int
`n_bytes`	`sizeof(int)`
`dev_info_ptr`	NULL

Description:

This command controls serial communication lines. The tcsendbreak(), tcdropline(), and ioctl() functions act as cover functions for many of the actions. If these cover functions don't provide suitable functionality, use this command directly.

Input:

The desired serial line control action. The *_CHG bits indicate which attributes you want to change, and the corresponding non-*_CHG bits are the on setting. For example, to turn CTS on, specify a value of _CTL_CTS_CHG | _CTL_CTS; to turn it off, specify a value of _CTL_CTS_CHG.


Device type	On value	Change bit	Description
General	_CTL_DTR	_CTL_DTR_CHG	Data terminal ready; you can OR in a duration
	_CTL_RTS	_CTL_RTS_CHG	Ready to send
	_CTL_BRK	_CTL_BRK_CHG	Break; you can OR in a duration
	_CTL_TIMED	_CTL_TIMED_CHG	Data ready timeout; you can OR in a duration
	_CTL_DSR	_CTL_DSR_CHG	Data set ready; for use when DSR is an output (USB device side serial class driver). You can OR in a duration.
	_CTL_DCD	_CTL_DCD_CHG	Data carrier detect; for use when DCD is an output (USB device side serial class driver). You can OR in a duration.
	_CTL_CTS	_CTL_CTS_CHG	Clear to send; for use when CTS is an output (USB device side serial class driver)
	_CTL_MASK	_CTL_MASK_CHG	Mask the reporting of errors
Serial	_SERCTL_DTR	_SERCTL_DTR_CHG	Data terminal ready
	_SERCTL_RTS	_SERCTL_RTS_CHG	Ready to send
	_SERCTL_BRK	_SERCTL_BRK_CHG	Break
	_SERCTL_LOOP	_SERCTL_LOOP_CHG	Loopback
	_SERCTL_DSR	_SERCTL_DSR_CHG	Data send ready
	_SERCTL_DCD	_SERCTL_DCD_CHG	Data carrier detect
	_SERCTL_CTS	_SERCTL_CTS_CHG	Clear to send
Console	_CONCTL_BELL	_CONCTL_BELL_CHG	Ring the bell
	_CONCTL_SCROLL	_CONCTL_SCROLL_CHG	Scroll lock
	_CONCTL_NUM	_CONCTL_NUM_CHG	Num lock
	_CONCTL_CAPS	_CONCTL_CAPS_CHG	Caps lock
	_CONCTL_INVISIBLE	_CONCTL_INVISIBLE_CHG	Don't talk to video hardware

You can use the following macros to shift a duration so that you can OR it into a command:

#define _CTL_DURATION(__duration)   ((__duration) << 16)
#define _SERCTL_DURATION(__duration) _CTL_DURATION(__duration)
#define _CONCTL_DURATION(__duration) _CTL_DURATION(__duration)

Output:

None.

Example:

Turn RTS on:

int i_Data, i_fd;
int RTS_TOGGLE;

fd = open ("/dev/ser1", O_RDONLY);

RTS_TOGGLE = 1; // Turn RTS on.

i_Data = _CTL_RTS_CHG | (RTS_TOGGLE ? _CTL_RTS : 0);

if (devctl (i_fd, DCMD_CHR_SERCTL, &i_Data, sizeof(i_Data), NULL) != EOK)
{
  /* Error */
}

Here's how to include a duration of 300 milliseconds in a command:

int duration = 300;
int cmd;

cmd = _SERCTL_DTR_CHG | _SERCTL_DURATION (duration);
if (devctl(fd, DCMD_CHR_SERCTL, &cmd, sizeof cmd, NULL) != EOK)
{
  /* Error */
}