From 5079df993c3ab45af10dc9a45b3b9e712fd56f23 Mon Sep 17 00:00:00 2001 From: Mike Frysinger Date: Mon, 21 May 2007 18:09:27 +0800 Subject: [PATCH] Blackfin arch: document why we have to touch the UART peripheral in our boot up code Signed-off-by: Mike Frysinger Signed-off-by: Bryan Wu Signed-off-by: Linus Torvalds --- arch/blackfin/mach-bf533/head.S | 3 ++- arch/blackfin/mach-bf537/head.S | 3 ++- arch/blackfin/mach-bf561/head.S | 3 ++- 3 files changed, 6 insertions(+), 3 deletions(-) diff --git a/arch/blackfin/mach-bf533/head.S b/arch/blackfin/mach-bf533/head.S index 1a54ff5f06..4db9e62409 100644 --- a/arch/blackfin/mach-bf533/head.S +++ b/arch/blackfin/mach-bf533/head.S @@ -173,7 +173,8 @@ ENTRY(__stext) STI R2; #endif - /* Initialise UART */ + /* Initialise UART - when booting from u-boot, the UART is not disabled + * so if we dont initalize here, our serial console gets hosed */ p0.h = hi(UART_LCR); p0.l = lo(UART_LCR); r0 = 0x0(Z); diff --git a/arch/blackfin/mach-bf537/head.S b/arch/blackfin/mach-bf537/head.S index aafc686749..b4377dddc1 100644 --- a/arch/blackfin/mach-bf537/head.S +++ b/arch/blackfin/mach-bf537/head.S @@ -181,7 +181,8 @@ ENTRY(__stext) SSYNC; #endif - /*Initialise UART*/ + /* Initialise UART - when booting from u-boot, the UART is not disabled + * so if we dont initalize here, our serial console gets hosed */ p0.h = hi(UART_LCR); p0.l = lo(UART_LCR); r0 = 0x0(Z); diff --git a/arch/blackfin/mach-bf561/head.S b/arch/blackfin/mach-bf561/head.S index 04f3ac33ab..9c8e6885f4 100644 --- a/arch/blackfin/mach-bf561/head.S +++ b/arch/blackfin/mach-bf561/head.S @@ -127,7 +127,8 @@ ENTRY(__stext) STI R2; #endif - /* Initialise UART*/ + /* Initialise UART - when booting from u-boot, the UART is not disabled + * so if we dont initalize here, our serial console gets hosed */ p0.h = hi(UART_LCR); p0.l = lo(UART_LCR); r0 = 0x0(Z); -- 2.39.5