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
diff --git a/drivers/console/console.S b/drivers/console/console.S
index b772363..797b564 100644
--- a/drivers/console/console.S
+++ b/drivers/console/console.S
@@ -54,7 +54,7 @@
* w1 - Uart clock in Hz
* w2 - Baud rate
* out: return 1 on success else 0 on error
- * Clobber list : x1 - x3
+ * Clobber list : x1 - x4
* -----------------------------------------------
*/
func console_init