u-boot/arch/mips/mach-mtmips/mt7628/lowlevel_init.S
Weijie Gao 02cd449f0b mips: mtmips: rewrite lowlevel codes of mt7628
This patch rewrites the mtmips architecture with the following changes:

1. Move MT7628 soc parts into a subfolder.
2. Lock parts of D-Cache as temporary stack.
3. Reimplement DDR initialization in C language.
4. Reimplement DDR calibration in a clear logic.
5. Add full support for auto size detection for DDR1 and DDR2.
6. Use accurate CPU clock depending on the input xtal frequency for timer
   and delay functions.

Note:

print_cpuinfo() has incompatible parts with MT7620 so it's moved into
mt7628 subfolder.

Reviewed-by: Stefan Roese <sr@denx.de>
Reviewed-by: Daniel Schwierzeck <daniel.schwierzeck@gmail.com>
Signed-off-by: Weijie Gao <weijie.gao@mediatek.com>
2020-04-27 20:29:33 +02:00

161 lines
3.4 KiB
ArmAsm

/* SPDX-License-Identifier: GPL-2.0 */
/*
* Copyright (C) 2020 MediaTek Inc.
*
* Author: Weijie Gao <weijie.gao@mediatek.com>
*/
#include <config.h>
#include <asm-offsets.h>
#include <asm/cacheops.h>
#include <asm/regdef.h>
#include <asm/mipsregs.h>
#include <asm/addrspace.h>
#include <asm/asm.h>
#include "mt7628.h"
/* Set temporary stack address range */
#ifndef CONFIG_SYS_INIT_SP_ADDR
#define CONFIG_SYS_INIT_SP_ADDR (CONFIG_SYS_SDRAM_BASE + \
CONFIG_SYS_INIT_SP_OFFSET)
#endif
#define CACHE_STACK_SIZE 0x4000
#define CACHE_STACK_BASE (CONFIG_SYS_INIT_SP_ADDR - CACHE_STACK_SIZE)
#define DELAY_USEC(us) ((58 * (us)) / 3)
.set noreorder
LEAF(mips_sram_init)
#ifndef CONFIG_SKIP_LOWLEVEL_INIT
/* Setup CPU PLL */
li t0, DELAY_USEC(1000000)
li t1, KSEG1ADDR(SYSCTL_BASE + SYSCTL_ROM_STATUS_REG)
li t2, KSEG1ADDR(SYSCTL_BASE + SYSCTL_CLKCFG0_REG)
_check_rom_status:
lw t3, 0(t1)
andi t3, t3, 1
bnez t3, _rom_normal
subu t0, t0, 1
bnez t0, _check_rom_status
nop
lw t3, 0(t2)
ori t3, (CPU_PLL_FROM_BBP | CPU_PLL_FROM_XTAL)
xori t3, CPU_PLL_FROM_BBP
b _cpu_pll_done
nop
_rom_normal:
lw t3, 0(t2)
ori t3, (CPU_PLL_FROM_BBP | CPU_PLL_FROM_XTAL | \
DIS_BBP_SLEEP | EN_BBP_CLK)
xori t3, (CPU_PLL_FROM_BBP | CPU_PLL_FROM_XTAL)
_cpu_pll_done:
sw t3, 0(t2)
li t2, KSEG1ADDR(RBUSCTL_BASE + RBUSCTL_DYN_CFG0_REG)
lw t3, 0(t2)
ori t3, t3, (CPU_FDIV_M | CPU_FFRAC_M)
xori t3, t3, (CPU_FDIV_M | CPU_FFRAC_M)
ori t3, t3, ((1 << CPU_FDIV_S) | (1 << CPU_FFRAC_S))
sw t3, 0(t2)
/* Clear WST & SPR bits in ErrCtl */
mfc0 t0, CP0_ECC
ins t0, zero, 30, 2
mtc0 t0, CP0_ECC
ehb
/* Simply initialize I-Cache */
li a0, 0
li a1, CONFIG_SYS_ICACHE_SIZE
mtc0 zero, CP0_TAGLO /* Zero to DDataLo */
1: cache INDEX_STORE_TAG_I, 0(a0)
addiu a0, CONFIG_SYS_ICACHE_LINE_SIZE
bne a0, a1, 1b
nop
/* Simply initialize D-Cache */
li a0, 0
li a1, CONFIG_SYS_DCACHE_SIZE
mtc0 zero, CP0_TAGLO, 2
2: cache INDEX_STORE_TAG_D, 0(a0)
addiu a0, CONFIG_SYS_DCACHE_LINE_SIZE
bne a0, a1, 2b
nop
/* Set KSEG0 Cachable */
mfc0 t0, CP0_CONFIG
and t0, t0, MIPS_CONF_IMPL
or t0, t0, CONF_CM_CACHABLE_NONCOHERENT
mtc0 t0, CP0_CONFIG
ehb
/* Lock D-Cache */
PTR_LI a0, CACHE_STACK_BASE /* D-Cache lock base */
li a1, CACHE_STACK_SIZE /* D-Cache lock size */
li a2, 0x1ffff800 /* Mask of DTagLo[PTagLo] */
3:
/* Lock one cacheline */
and t0, a0, a2
ori t0, 0xe0 /* Valid & Dirty & Lock bits */
mtc0 t0, CP0_TAGLO, 2 /* Write to DTagLo */
ehb
cache INDEX_STORE_TAG_D, 0(a0)
addiu a0, CONFIG_SYS_DCACHE_LINE_SIZE
sub a1, CONFIG_SYS_DCACHE_LINE_SIZE
bnez a1, 3b
nop
#endif /* CONFIG_SKIP_LOWLEVEL_INIT */
jr ra
nop
END(mips_sram_init)
NESTED(lowlevel_init, 0, ra)
/* Save ra and do real lowlevel initialization */
move s0, ra
PTR_LA t9, mt7628_init
jalr t9
nop
move ra, s0
#if CONFIG_IS_ENABLED(INIT_STACK_WITHOUT_MALLOC_F)
/* Set malloc base */
li t0, (CONFIG_SYS_INIT_SP_ADDR + 15) & (~15)
PTR_S t0, GD_MALLOC_BASE(k0) # gd->malloc_base offset
#endif
/* Write back data in locked cache to DRAM */
PTR_LI a0, CACHE_STACK_BASE /* D-Cache unlock base */
li a1, CACHE_STACK_SIZE /* D-Cache unlock size */
1:
cache HIT_WRITEBACK_INV_D, 0(a0)
addiu a0, CONFIG_SYS_DCACHE_LINE_SIZE
sub a1, CONFIG_SYS_DCACHE_LINE_SIZE
bnez a1, 1b
nop
/* Set KSEG0 Uncached */
mfc0 t0, CP0_CONFIG
and t0, t0, MIPS_CONF_IMPL
or t0, t0, CONF_CM_UNCACHED
mtc0 t0, CP0_CONFIG
ehb
jr ra
nop
END(lowlevel_init)