forked from rrcarlosr/Jetpack
30 lines
1.1 KiB
Plaintext
30 lines
1.1 KiB
Plaintext
|
U-Boot for Freescale i.MX31
|
||
|
|
|
||
|
|
This file contains information for the port of U-Boot to the Freescale
|
||
|
|
i.MX31 SoC.
|
||
|
|
|
||
|
|
1. CONFIGURATION OPTIONS/SETTINGS
|
||
|
|
---------------------------------
|
||
|
|
|
||
|
|
1.1 Configuration of MC13783 SPI bus
|
||
|
|
------------------------------------
|
||
|
|
The power management companion chip MC13783 is connected to the
|
||
|
|
i.MX31 via an SPI bus. Use the following configuration options
|
||
|
|
to setup the bus and chip select used for a particular board.
|
||
|
|
|
||
|
|
CONFIG_MC13783_SPI_BUS -- defines the SPI bus the MC13783 is connected to.
|
||
|
|
Note that 0 is CSPI1, 1 is CSPI2 and 2 is CSPI3.
|
||
|
|
CONFIG_MC13783_SPI_CS -- define the chip select the MC13783 s connected to.
|
||
|
|
|
||
|
|
1.2 Timer precision
|
||
|
|
-------------------
|
||
|
|
CONFIG_MX31_TIMER_HIGH_PRECISION
|
||
|
|
|
||
|
|
Enable higher precision timer. The low-precision timer
|
||
|
|
(default) provides approximately 4% error, whereas the
|
||
|
|
high-precision timer is about 0.4% accurate. The extra
|
||
|
|
accuracy is achieved at the cost of higher computational
|
||
|
|
overhead, which, in places where time is measured, should
|
||
|
|
not be critical, so, it should be safe to enable this
|
||
|
|
option.
|