tree 2246537b57b322e106a2e4cc618e0958c513dad6
parent 9cf86093e58613bbdc690bdcf47fbd8ddcd24442
author Juan Castillo <juan.castillo@arm.com> 1448549535 +0000
committer Juan Castillo <juan.castillo@arm.com> 1453397267 +0000

Disable PL011 UART before configuring it

The PL011 TRM (ARM DDI 0183G) specifies that the UART must be
disabled before any of the control registers are programmed. The
PL011 driver included in TF does not disable the UART, so the
initialization in BL2 and BL31 is violating this requirement
(and potentially in BL1 if the UART is enabled after reset).

This patch modifies the initialization function in the PL011
console driver to disable the UART before programming the
control registers.

Register clobber list and documentation updated.

Fixes ARM-software/tf-issues#300

Change-Id: I839b2d681d48b03f821ac53663a6a78e8b30a1a1