RADIO(4) BSD Kernel Interfaces Manual RADIO(4)NAMEradio — device-independent radio driver layer
SYNOPSIS
radio* at az?
radio* at bktr?
radio* at gtp?
radio* at rt?
radio* at rtii?
radio* at sf2r?
radio* at udsbr?
#include <sys/types.h>
#include <sys/ioctl.h>
#include <sys/radioio.h>
DESCRIPTION
The radio driver provides support for various FM radio cards. It pro‐
vides an uniform programming interface layer above different underlying
radio hardware drivers.
For radio tuner controlling there is a single device file available:
/dev/radio.
The following ioctl(2) commands are supported:
RIOCSSRCH (int)
This command assumes that a signal search is required and gives
direction of search to the driver - 0 to search down and any non-
zero value to search up.
RIOCGINFO (struct radio_info)
RIOCSINFO (struct radio_info)
Get or set the current hardware device information into the
struct radio_info structure.
struct radio_info {
int mute;
int volume;
int stereo;
int rfreq; /* reference frequency */
int lock; /* locking field strength */
uint32_t freq; /* in kHz */
uint32_t caps; /* card capabilities */
#define RADIO_CAPS_DETECT_STEREO (1<<0)
#define RADIO_CAPS_DETECT_SIGNAL (1<<1)
#define RADIO_CAPS_SET_MONO (1<<2)
#define RADIO_CAPS_HW_SEARCH (1<<3)
#define RADIO_CAPS_HW_AFC (1<<4)
#define RADIO_CAPS_REFERENCE_FREQ (1<<5)
#define RADIO_CAPS_LOCK_SENSITIVITY (1<<6)
#define RADIO_CARD_TYPE (0xFF<<16)
uint32_t info;
#define RADIO_INFO_STEREO (1<<0)
#define RADIO_INFO_SIGNAL (1<<1)
};
The mute field is a boolean.
The volume field holds the card volume information and can be at
most 255.
The stereo field is a boolean.
The rfreq holds information about the card reference frequency
(not all cards support this feature).
The lock field holds information about the card locking field
strength during an automatic search for cards that support this
feature.
The freq field is the frequency in kHz the card is tuned to.
The caps field is read-only and describes the card capabilities.
The capabilities can have following values:
RADIO_CAPS_DETECT_STEREO
The device can determine is it tuned to a stereo signal.
RADIO_CAPS_DETECT_SIGNAL
The device can determine is it tuned or not.
RADIO_CAPS_SET_MONO
The device capable to forcible set its output to mono.
RADIO_CAPS_HW_SEARCH
The device can do hardware search.
RADIO_CAPS_HW_AFC
The device has an internal hardware automatic frequency
control.
RADIO_CAPS_REFERENCE_FREQ
The device allow to change the reference frequency of a
received signal.
RADIO_CAPS_LOCK_SENSITIVITY
The device allow to change the station lock sensitivity
used during search operation.
RADIO_CARD_TYPE
Some cards have several different incarnations. This
allow to determine the variant of the card. Currently
not used.
The info field is read-only and describes the current state of
the card - tuned/not tuned, stereo signal/mono signal.
RADIO_INFO_STEREO
Informs whether the device receives a stereo or mono sig‐
nal.
RADIO_INFO_SIGNAL
Informs whether the device receives a valid signal or
noise.
FILES
/dev/radio
SEE ALSOradioctl(1), ioctl(2), az(4), bktr(4), gtp(4), rt(4), rtii(4), sf2r(4),
udsbr(4)HISTORY
The radio device driver appeared in OpenBSD 3.0 and NetBSD 1.6.
AUTHORS
The radio driver was written by Vladimir Popov and Maxim Tsyplakov. The
man page was written by Vladimir Popov.
BSD October 20, 2001 BSD
