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RADIO(4)                     Device Drivers Manual                    RADIO(4)

NAME
     radio - 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 slurm?
     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
     provides 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
                     signal.
             RADIO_INFO_SIGNAL
                     Informs whether the device receives a valid signal or
                     noise.

FILES
     /dev/radio

SEE ALSO
     radioctl(1), ioctl(2), az(4), bktr(4), gtp(4), rt(4), rtii(4), sf2r(4),
     slurm(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 for
     OpenBSD and ported to NetBSD by Lennart Augustsson.  The man page was
     written by Vladimir Popov.

NetBSD 10.99                   October 20, 2001                   NetBSD 10.99