Hi Tony, This patch adds a brief write up about the earlier posted HDQ/1-wire driver. Please consider this patch. Regards, Madhu ----------------------------------------------------------------------------------- This patch adds a brief documentation about omap2430/3430 HDQ/1-wire driver. Signed-off-by: Madhusudhan Chikkature<madhu.cr@xxxxxx> --- Documentation/w1/masters/omap-hdq | 46 ++++++++++++++++++++++++++++++++++++++ 1 files changed, 46 insertions(+) Index: linux-omap-2.6/Documentation/w1/masters/omap-hdq =================================================================== --- /dev/null 1970-01-01 00:00:00.000000000 +0000 +++ linux-omap-2.6/Documentation/w1/masters/omap-hdq 2007-12-17 15:43:26.306248879 +0530 @@ -0,0 +1,46 @@ +Kernel driver for omap HDQ/1-wire module. +======================================== + +Supported chips: +================ + HDQ/1-wire controller on the TI OMAP 2430/3430 platforms. + +A useful link about HDQ basics: +=============================== +http://focus.ti.com/lit/an/slua408/slua408.pdf + +Description: +============ +The HDQ/1-Wire module of TI OMAP2430/3430 platforms implement the hardware +protocol of the master functions of the Benchmark HDQ and the Dallas +Semiconductor 1-Wire. protocols. These protocols use a single wire for +communication between the master (HDQ/1-Wire controller) and the slave +(HDQ/1-Wire external compliant device). + +A typical application of the HDQ/1-Wire module is the communication with battery +monitor (gas gauge) integrated circuits. + +The controller supports operation in both HDQ and 1-wire mode. The essential +difference between the HDQ and 1-wire mode is how the slave device responds to +initialization pulse.In HDQ mode, the firmware does not require the host to +create an initialization pulse to the slave.However, the slave can be reset by +using an initialization pulse (also referred to as a break pulse).The slave +does not respond with a presence pulse as it does in the 1-Wire protocol. + +Remarks: +======== +The driver (drivers/w1/masters/omap_hdq.c) supports the HDQ mode of the +controller. In this mode, as we can not read the ID which obeys the W1 +spec(family:id:crc), a module parameter can be passed to the driver which will +be used to calculate the CRC and pass back an appropriate slave ID to the W1 +core. + +By default the master driver and the BQ slave i/f +driver(drivers/w1/slaves/w1_bq27000.c) sets the ID to 1. +Please note to load both the modules with a different ID if required, but note +that the ID used should be same for both master and slave driver loading. + +e.g: +insmod omap_hdq.ko W1_ID=2 +inamod w1_bq27000.ko F_ID=2 + - To unsubscribe from this list: send the line "unsubscribe linux-omap" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
