linux/arch/arm/mach-omap2/include/mach/debug-macro.S
Jason Wang 7e788b4289 omap: Fix DEBUG_LL uart to access phys addr when MMU isn't enable
Now we use a memory address to store the debug port info, So we need
to read/write this address when we choose DEBUG_LL. When MMU isn't
enable(I.E. the begining part of init stage of the linux kernel boot),
we need to access physical address instead of virtual address,
otherwise the kernel will crash.

Signed-off-by: Jason Wang <jason77.wang@gmail.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>
2010-08-04 12:17:53 +03:00

146 lines
4.1 KiB
ArmAsm

/* arch/arm/mach-omap2/include/mach/debug-macro.S
*
* Debugging macro include header
*
* Copyright (C) 1994-1999 Russell King
* Moved from linux/arch/arm/kernel/debug.S by Ben Dooks
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*
*/
#include <linux/serial_reg.h>
#include <asm/memory.h>
#include <plat/serial.h>
#define UART_OFFSET(addr) ((addr) & 0x00ffffff)
.pushsection .data
omap_uart_phys: .word 0
omap_uart_virt: .word 0
omap_uart_lsr: .word 0
.popsection
/*
* Note that this code won't work if the bootloader passes
* a wrong machine ID number in r1. To debug, just hardcode
* the desired UART phys and virt addresses temporarily into
* the omap_uart_phys and omap_uart_virt above.
*/
.macro addruart, rx, tmp
/* Use omap_uart_phys/virt if already configured */
10: mrc p15, 0, \rx, c1, c0
tst \rx, #1 @ MMU enabled?
ldreq \rx, =__virt_to_phys(omap_uart_phys) @ physical base address
ldrne \rx, =omap_uart_virt @ virtual base address
ldr \rx, [\rx, #0]
cmp \rx, #0 @ is port configured?
bne 99f @ already configured
/* Check the debug UART configuration set in uncompress.h */
mrc p15, 0, \rx, c1, c0
tst \rx, #1 @ MMU enabled?
ldreq \rx, =OMAP_UART_INFO
ldrne \rx, =__phys_to_virt(OMAP_UART_INFO)
ldr \rx, [\rx, #0]
/* Select the UART to use based on the UART1 scratchpad value */
cmp \rx, #0 @ no port configured?
beq 21f @ if none, try to use UART1
cmp \rx, #OMAP2UART1 @ OMAP2/3/4UART1
beq 21f @ configure OMAP2/3/4UART1
cmp \rx, #OMAP2UART2 @ OMAP2/3/4UART2
beq 22f @ configure OMAP2/3/4UART2
cmp \rx, #OMAP2UART3 @ only on 24xx
beq 23f @ configure OMAP2UART3
cmp \rx, #OMAP3UART3 @ only on 34xx
beq 33f @ configure OMAP3UART3
cmp \rx, #OMAP4UART3 @ only on 44xx
beq 43f @ configure OMAP4UART3
cmp \rx, #OMAP3UART4 @ only on 36xx
beq 34f @ configure OMAP3UART4
cmp \rx, #OMAP4UART4 @ only on 44xx
beq 44f @ configure OMAP4UART4
cmp \rx, #ZOOM_UART @ only on zoom2/3
beq 95f @ configure ZOOM_UART
/* Configure the UART offset from the phys/virt base */
21: mov \rx, #UART_OFFSET(OMAP2_UART1_BASE) @ omap2/3/4
b 98f
22: mov \rx, #UART_OFFSET(OMAP2_UART2_BASE) @ omap2/3/4
b 98f
23: mov \rx, #UART_OFFSET(OMAP2_UART3_BASE)
b 98f
33: mov \rx, #UART_OFFSET(OMAP3_UART1_BASE)
add \rx, \rx, #0x00fb0000
add \rx, \rx, #0x00006000 @ OMAP3_UART3_BASE
b 98f
34: mov \rx, #UART_OFFSET(OMAP3_UART1_BASE)
add \rx, \rx, #0x00fb0000
add \rx, \rx, #0x00028000 @ OMAP3_UART4_BASE
b 98f
43: mov \rx, #UART_OFFSET(OMAP4_UART3_BASE)
b 98f
44: mov \rx, #UART_OFFSET(OMAP4_UART4_BASE)
b 98f
95: ldr \rx, =ZOOM_UART_BASE
mrc p15, 0, \tmp, c1, c0
tst \tmp, #1 @ MMU enabled?
ldreq \tmp, =__virt_to_phys(omap_uart_phys)
ldrne \tmp, =omap_uart_phys
str \rx, [\tmp, #0]
ldr \rx, =ZOOM_UART_VIRT
ldreq \tmp, =__virt_to_phys(omap_uart_virt)
ldrne \tmp, =omap_uart_virt
str \rx, [\tmp, #0]
mov \rx, #(UART_LSR << ZOOM_PORT_SHIFT)
ldreq \tmp, =__virt_to_phys(omap_uart_lsr)
ldrne \tmp, =omap_uart_lsr
str \rx, [\tmp, #0]
b 10b
/* Store both phys and virt address for the uart */
98: add \rx, \rx, #0x48000000 @ phys base
mrc p15, 0, \tmp, c1, c0
tst \tmp, #1 @ MMU enabled?
ldreq \tmp, =__virt_to_phys(omap_uart_phys)
ldrne \tmp, =omap_uart_phys
str \rx, [\tmp, #0]
sub \rx, \rx, #0x48000000 @ phys base
add \rx, \rx, #0xfa000000 @ virt base
ldreq \tmp, =__virt_to_phys(omap_uart_virt)
ldrne \tmp, =omap_uart_virt
str \rx, [\tmp, #0]
mov \rx, #(UART_LSR << OMAP_PORT_SHIFT)
ldreq \tmp, =__virt_to_phys(omap_uart_lsr)
ldrne \tmp, =omap_uart_lsr
str \rx, [\tmp, #0]
b 10b
99:
.endm
.macro senduart,rd,rx
strb \rd, [\rx]
.endm
.macro busyuart,rd,rx
1001: mrc p15, 0, \rd, c1, c0
tst \rd, #1 @ MMU enabled?
ldreq \rd, =__virt_to_phys(omap_uart_lsr)
ldrne \rd, =omap_uart_lsr
ldr \rd, [\rd, #0]
ldrb \rd, [\rx, \rd]
and \rd, \rd, #(UART_LSR_TEMT | UART_LSR_THRE)
teq \rd, #(UART_LSR_TEMT | UART_LSR_THRE)
bne 1001b
.endm
.macro waituart,rd,rx
.endm