owll9
Dallas semiconductor 1-wire link layer interface
Usage
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);
Overview
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.
Legal
1-Wire is a registered trademark of Maxim Integrated Products, Inc.
Releases
25 releases since FreeBSD 11.0-RELEASE; the text changed 11 times.