u-boot/board/ti/dra7xx
Roger Quadros a5878f1933 ARM: DRA7-evm: prevent DCAN1 _wait_target_disable failure in kernel
If board is booted with transitions happening on DCAN1 pins then
the following warning is seen in the kernel at boot when the
hwmod layer initializes.

"omap_hwmod: dcan1: _wait_target_disable failed"

This is because DCAN1 module's SWAKEUP mechanism is broken
and it fails to correctly turn OFF if it sees a transition on the
DCAN1 pins. Suggested workaround is to keep DCAN1 pins in safe mode
while enabling/disabling DCAN1 module.

The hwmod layer enables and disables all modules at boot
and we have no opportunity to put the DCAN1 pins in safe mode
at that point.

DCAN1 is not used by u-boot so it doesn't matter to it if these
pins are in safe mode. The kernel driver correctly configures
the right mode when DCAN1 is active.

Signed-off-by: Roger Quadros <rogerq@ti.com>
2015-07-08 18:26:42 -04:00
..
evm.c ARM: DRA7: CPSW: Remove IO delay hack 2015-06-12 13:02:06 -04:00
Kconfig kconfig: remove redundant "string" type in arch and board Kconfigs 2014-09-13 16:43:55 -04:00
MAINTAINERS Add board MAINTAINERS files 2014-07-30 08:48:06 -04:00
Makefile board: ti: convert makefiles to Kbuild style 2013-10-31 13:26:44 -04:00
mux_data.h ARM: DRA7-evm: prevent DCAN1 _wait_target_disable failure in kernel 2015-07-08 18:26:42 -04:00
README mmc: Add 'mmc rst-function' sub-command 2014-04-02 13:02:58 +03:00

Summary
=======

This document covers various features of the 'dra7xx_evm' build and some
related uses.

eMMC boot partition use
=======================

It is possible, depending on SYSBOOT configuration to boot from the eMMC
boot partitions using (name depending on documentation referenced)
Alternative Boot operation mode or Boot Sequence Option 1/2.  In this
example we load MLO and u-boot.img from the build into DDR and then use
'mmc bootbus' to set the required rate (see TRM) and 'mmc partconfig' to
set boot0 as the boot device.
U-Boot # setenv autoload no
U-Boot # usb start
U-Boot # dhcp
U-Boot # mmc dev 1 1
U-Boot # tftp ${loadaddr} dra7xx/MLO
U-Boot # mmc write ${loadaddr} 0 100
U-Boot # tftp ${loadaddr} dra7xx/u-boot.img
U-Boot # mmc write ${loadaddr} 300 400
U-Boot # mmc bootbus 1 2 0 2
U-Boot # mmc partconf 1 1 1 0
U-Boot # mmc rst-function 1 1