focal (9) owll.9freebsd.gz

NAME

     owll OWLL_WRITE_ONE, OWLL_WRITE_ZERO, OWLL_READ_DATA, OWLL_REASET_AND_PRESENCE — Dallas Semiconductor
     1-Wire Link Layer Interface

SYNOPSIS

     int
     OWLL_WRITE_ONE(device_t lldev, struct ow_timing *timing);

     int
     OWLL_WRITE_ZERO(device_t lldev, struct ow_timing *timing);

     int
     OWLL_READ_DATA(device_t lldev, struct ow_timing *timing, int *bit);

     int
     OWLL_RESET_AND_PRESENCE(device_t lldev, struct ow_timing *timing, int *bit);

DESCRIPTION

     The owll interface provides access to the link layer of the Dallas Semiconductor 1-Wire from upper layers
     of the protocol.

     OWLL_WRITE_ONE() and OWLL_WRITE_ZERO() writes a one bit or a zero bit respectively on the 1-Wire bus.

     OWLL_READ_DATA() reads one bit from the 1-Wire bus.  This is often referred to as a “Read Time Slot” in the
     1-Wire device data sheets.

     The OWLL_RESET_AND_PRESENCE() function starts a reset sequence and detects if any device(s) are present on
     the bus.  This is the beginning of all 1-Wire transactions.

NOTES

     This interface is intended to be used only by the ow(4) device to talk to the low-level bus.  By
     convention, the device that implements this interface is called owc(4).  Only devices that implement own(9)
     should call these interfaces.

SEE ALSO

     ow(4), owc(4), own(9)

LEGAL

     1-Wire is a registered trademark of Maxim Integrated Products, Inc.

HISTORY

     The owll driver first appeared in FreeBSD 11.0.

AUTHORS

     The owll device driver and this manual page were written by Warner Losh.