36 lines
1.1 KiB
Text
36 lines
1.1 KiB
Text
TPS65950 Driver (Power Management IC)
|
|
=====================================
|
|
|
|
Overview
|
|
--------
|
|
|
|
This driver is for the power management chip commonly found on the
|
|
BeagleBoard-xM.
|
|
|
|
Limitations
|
|
-----------
|
|
|
|
The TPS65950 has a pin labelled MSECURE which provides a form of write
|
|
protection. Depending on the pin's state (high or low), writing to certain
|
|
registers is disabled or enabled. The pin is driven by a GPIO on the SoC.
|
|
There isn't a good way to access that pin on the SoC yet, so the PMIC
|
|
is always in the default insecure mode. It isn't really insecure as this
|
|
driver is the only one that the i2c bus driver will allow to access the
|
|
PMIC.
|
|
|
|
This is a huge chip. It has two I2C controllers, one with 4 slave addresses
|
|
hosting 256 registers per address. The TRM is over 900 pages. Given the
|
|
limited usefulness of some peripherals on the chip, not everything is
|
|
implemented.
|
|
|
|
Testing the Code
|
|
----------------
|
|
|
|
Starting up an instance:
|
|
|
|
/bin/service up /usr/sbin/tps65950 -label tps65950.1.48 \
|
|
-args 'bus=1 address=0x48'
|
|
|
|
Killing an instance:
|
|
|
|
/bin/service down tps65950.1.48
|