1Kernel driver for omap HDQ/1-wire module.
2========================================
3
4Supported chips:
5================
6	HDQ/1-wire controller on the TI OMAP 2430/3430 platforms.
7
8A useful link about HDQ basics:
9===============================
10http://focus.ti.com/lit/an/slua408a/slua408a.pdf
11
12Description:
13============
14The HDQ/1-Wire module of TI OMAP2430/3430 platforms implement the hardware
15protocol of the master functions of the Benchmark HDQ and the Dallas
16Semiconductor 1-Wire protocols. These protocols use a single wire for
17communication between the master (HDQ/1-Wire controller) and the slave
18(HDQ/1-Wire external compliant device).
19
20A typical application of the HDQ/1-Wire module is the communication with battery
21monitor (gas gauge) integrated circuits.
22
23The controller supports operation in both HDQ and 1-wire mode. The essential
24difference between the HDQ and 1-wire mode is how the slave device responds to
25initialization pulse.In HDQ mode, the firmware does not require the host to
26create an initialization pulse to the slave.However, the slave can be reset by
27using an initialization pulse (also referred to as a break pulse).The slave
28does not respond with a presence pulse as it does in the 1-Wire protocol.
29
30Remarks:
31========
32The driver (drivers/w1/masters/omap_hdq.c) supports the HDQ mode of the
33controller. In this mode, as we can not read the ID which obeys the W1
34spec(family:id:crc), a module parameter can be passed to the driver which will
35be used to calculate the CRC and pass back an appropriate slave ID to the W1
36core.
37
38By default the master driver and the BQ slave i/f
39driver(drivers/w1/slaves/w1_bq27000.c) sets the ID to 1.
40Please note to load both the modules with a different ID if required, but note
41that the ID used should be same for both master and slave driver loading.
42
43e.g:
44insmod omap_hdq.ko W1_ID=2
45inamod w1_bq27000.ko F_ID=2
46
47The driver also supports 1-wire mode. In this mode, there is no need to
48pass slave ID as parameter. The driver will auto-detect slaves connected
49to the bus using SEARCH_ROM procedure. 1-wire mode can be selected by
50setting "ti,mode" property to "1w" in DT (see
51Documentation/devicetree/bindings/w1/omap-hdq.txt for more details).
52By default driver is in HDQ mode.
53