owll
OWLL_WRITE_ONE
,
OWLL_WRITE_ZERO
,
OWLL_READ_DATA
,
OWLL_REASET_AND_PRESENCE
—
Dallas Semiconductor 1-Wire Link Layer
Interface
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);
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.
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.
ow(4),
owc(4),
own(9)
1-Wire is a registered trademark of Maxim Integrated Products, Inc.
The
owll
driver first appeared in
FreeBSD 11.0.
The
owll
device driver and this manual page
were written by
Warner Losh.