u-boot/arch/arm/cpu/armv7/uniphier/lowlevel_init.S
Masahiro Yamada b4ad44baab ARM: UniPhier: add UART initialization routine for low-level debug
The low-level debugging functions are useful to debug the early boot
stage where the full UART driver is not available.

UniPhier SoCs need to initialize the UART port 0 to use this feature.
The initialization routine is called at the very entry of the
lowlevel_init().

Signed-off-by: Masahiro Yamada <yamada.m@jp.panasonic.com>
2015-01-08 23:01:56 +09:00

163 lines
4.3 KiB
ArmAsm

/*
* Copyright (C) 2012-2014 Panasonic Corporation
* Author: Masahiro Yamada <yamada.m@jp.panasonic.com>
*
* SPDX-License-Identifier: GPL-2.0+
*/
#include <config.h>
#include <linux/linkage.h>
#include <asm/system.h>
#include <asm/arch/led.h>
#include <asm/arch/arm-mpcore.h>
#include <asm/arch/sbc-regs.h>
ENTRY(lowlevel_init)
mov r8, lr @ persevere link reg across call
/*
* The UniPhier Boot ROM loads SPL code to the L2 cache.
* But CPUs can only do instruction fetch now because start.S has
* cleared C and M bits.
* First we need to turn on MMU and Dcache again to get back
* data access to L2.
*/
mrc p15, 0, r0, c1, c0, 0 @ SCTLR (System Contrl Register)
orr r0, r0, #(CR_C | CR_M) @ enable MMU and Dcache
mcr p15, 0, r0, c1, c0, 0
#ifdef CONFIG_DEBUG_LL
bl setup_lowlevel_debug
#endif
/*
* Now we are using the page table embedded in the Boot ROM.
* It is not handy since it is not a straight mapped table for sLD3.
* What we need to do next is to switch over to the page table in SPL.
*/
ldr r3, =init_page_table @ page table must be 16KB aligned
/* Disable MMU and Dcache before switching Page Table */
mrc p15, 0, r0, c1, c0, 0 @ SCTLR (System Contrl Register)
bic r0, r0, #(CR_C | CR_M) @ disable MMU and Dcache
mcr p15, 0, r0, c1, c0, 0
bl enable_mmu
#ifdef CONFIG_UNIPHIER_SMP
/*
* ACTLR (Auxiliary Control Register) for Cortex-A9
* bit[9] Parity on
* bit[8] Alloc in one way
* bit[7] EXCL (Exclusive cache bit)
* bit[6] SMP
* bit[3] Write full line of zeros mode
* bit[2] L1 Prefetch enable
* bit[1] L2 prefetch enable
* bit[0] FW (Cache and TLB maintenance broadcast)
*/
mrc p15, 0, r0, c1, c0, 1 @ ACTLR (Auxiliary Control Register)
orr r0, r0, #0x41 @ enable SMP, FW bit
mcr p15, 0, r0, c1, c0, 1
/* branch by CPU ID */
mrc p15, 0, r0, c0, c0, 5 @ MPIDR (Multiprocessor Affinity Register)
and r0, r0, #0x3
cmp r0, #0x0
beq primary_cpu
ldr r1, =ROM_BOOT_ROMRSV2
mov r0, #0
str r0, [r1]
0: wfe
ldr r0, [r1]
cmp r0, #0
beq 0b
bx r0 @ r0: entry point of U-Boot main for the secondary CPU
primary_cpu:
ldr r1, =ROM_BOOT_ROMRSV2
ldr r0, =_start @ entry for the secondary CPU
str r0, [r1]
ldr r0, [r1] @ make sure str is complete before sev
sev @ kick the sedoncary CPU
mrc p15, 4, r1, c15, c0, 0 @ Configuration Base Address Register
bfc r1, #0, #13 @ clear bit 12-0
mov r0, #-1
str r0, [r1, #SCU_INV_ALL] @ SCU Invalidate All Register
mov r0, #1 @ SCU enable
str r0, [r1, #SCU_CTRL] @ SCU Control Register
#endif
bl setup_init_ram @ RAM area for temporary stack pointer
mov lr, r8 @ restore link
mov pc, lr @ back to my caller
ENDPROC(lowlevel_init)
ENTRY(enable_mmu)
mrc p15, 0, r0, c2, c0, 2 @ TTBCR (Translation Table Base Control Register)
bic r0, r0, #0x37
orr r0, r0, #0x20 @ disable TTBR1
mcr p15, 0, r0, c2, c0, 2
orr r0, r3, #0x8 @ Outer Cacheability for table walks: WBWA
mcr p15, 0, r0, c2, c0, 0 @ TTBR0
mov r0, #0
mcr p15, 0, r0, c8, c7, 0 @ invalidate TLBs
mov r0, #-1 @ manager for all domains (No permission check)
mcr p15, 0, r0, c3, c0, 0 @ DACR (Domain Access Control Register)
dsb
isb
/*
* MMU on:
* TLBs was already invalidated in "../start.S"
* So, we don't need to invalidate it here.
*/
mrc p15, 0, r0, c1, c0, 0 @ SCTLR (System Contrl Register)
orr r0, r0, #(CR_C | CR_M) @ MMU and Dcache enable
mcr p15, 0, r0, c1, c0, 0
mov pc, lr
ENDPROC(enable_mmu)
#include <asm/arch/ssc-regs.h>
#define BOOT_RAM_SIZE (SSC_WAY_SIZE)
#define BOOT_WAY_BITS (0x00000100) /* way 8 */
ENTRY(setup_init_ram)
/*
* Touch to zero for the boot way
*/
0:
/*
* set SSCOQM, SSCOQAD, SSCOQSZ, SSCOQWN in this order
*/
ldr r0, = 0x00408006 @ touch to zero with address range
ldr r1, = SSCOQM
str r0, [r1]
ldr r0, = (CONFIG_SYS_INIT_SP_ADDR - BOOT_RAM_SIZE) @ base address
ldr r1, = SSCOQAD
str r0, [r1]
ldr r0, = BOOT_RAM_SIZE
ldr r1, = SSCOQSZ
str r0, [r1]
ldr r0, = BOOT_WAY_BITS
ldr r1, = SSCOQWN
str r0, [r1]
ldr r1, = SSCOPPQSEF
ldr r0, [r1]
cmp r0, #0 @ check if the command is successfully set
bne 0b @ try again if an error occurres
ldr r1, = SSCOLPQS
1:
ldr r0, [r1]
cmp r0, #0x4
bne 1b @ wait until the operation is completed
str r0, [r1] @ clear the complete notification flag
mov pc, lr
ENDPROC(setup_init_ram)