spr_lowlevel_init.S
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/*
* (C) Copyright 2006
* Vipin Kumar, ST Micoelectronics, vipin.kumar@st.com.
*
* SPDX-License-Identifier: GPL-2.0+
*/
#include <config.h>
/*
* platform specific initializations are already done in Xloader
* Initializations already done include
* DDR, PLLs, IP's clock enable and reset release etc
*/
.globl lowlevel_init
lowlevel_init:
/* By default, U-Boot switches CPU to low-vector */
/* Revert this as we work in high vector even in U-Boot */
mrc p15, 0, r0, c1, c0, 0
orr r0, r0, #0x00002000
mcr p15, 0, r0, c1, c0, 0
mov pc, lr
/* void setfreq(unsigned int device, unsigned int frequency) */
.global setfreq
setfreq:
stmfd sp!,{r14}
stmfd sp!,{r0-r12}
mov r8,sp
ldr sp,SRAM_STACK_V
/* Saving the function arguements for later use */
mov r4,r0
mov r5,r1
/* Putting DDR into self refresh */
ldr r0,DDR_07_V
ldr r1,[r0]
ldr r2,DDR_ACTIVE_V
bic r1, r1, r2
str r1,[r0]
ldr r0,DDR_57_V
ldr r1,[r0]
ldr r2,CYCLES_MASK_V
bic r1, r1, r2
ldr r2,REFRESH_CYCLES_V
orr r1, r1, r2, lsl #16
str r1,[r0]
ldr r0,DDR_07_V
ldr r1,[r0]
ldr r2,SREFRESH_MASK_V
orr r1, r1, r2
str r1,[r0]
/* flush pipeline */
b flush
.align 5
flush:
/* Delay to ensure self refresh mode */
ldr r0,SREFRESH_DELAY_V
delay:
sub r0,r0,#1
cmp r0,#0
bne delay
/* Putting system in slow mode */
ldr r0,SCCTRL_V
mov r1,#2
str r1,[r0]
/* Changing PLL(1/2) frequency */
mov r0,r4
mov r1,r5
cmp r4,#0
beq pll1_freq
/* Change PLL2 (DDR frequency) */
ldr r6,PLL2_FREQ_V
ldr r7,PLL2_CNTL_V
b pll2_freq
pll1_freq:
/* Change PLL1 (CPU frequency) */
ldr r6,PLL1_FREQ_V
ldr r7,PLL1_CNTL_V
pll2_freq:
mov r0,r6
ldr r1,[r0]
ldr r2,PLLFREQ_MASK_V
bic r1,r1,r2
mov r2,r5,lsr#1
orr r1,r1,r2,lsl#24
str r1,[r0]
mov r0,r7
ldr r1,P1C0A_V
str r1,[r0]
ldr r1,P1C0E_V
str r1,[r0]
ldr r1,P1C06_V
str r1,[r0]
ldr r1,P1C0E_V
str r1,[r0]
lock:
ldr r1,[r0]
and r1,r1,#1
cmp r1,#0
beq lock
/* Putting system back to normal mode */
ldr r0,SCCTRL_V
mov r1,#4
str r1,[r0]
/* Putting DDR back to normal */
ldr r0,DDR_07_V
ldr r1,[R0]
ldr r2,SREFRESH_MASK_V
bic r1, r1, r2
str r1,[r0]
ldr r2,DDR_ACTIVE_V
orr r1, r1, r2
str r1,[r0]
/* Delay to ensure self refresh mode */
ldr r0,SREFRESH_DELAY_V
1:
sub r0,r0,#1
cmp r0,#0
bne 1b
mov sp,r8
/* Resuming back to code */
ldmia sp!,{r0-r12}
ldmia sp!,{pc}
SCCTRL_V:
.word 0xfca00000
PLL1_FREQ_V:
.word 0xfca8000C
PLL1_CNTL_V:
.word 0xfca80008
PLL2_FREQ_V:
.word 0xfca80018
PLL2_CNTL_V:
.word 0xfca80014
PLLFREQ_MASK_V:
.word 0xff000000
P1C0A_V:
.word 0x1C0A
P1C0E_V:
.word 0x1C0E
P1C06_V:
.word 0x1C06
SREFRESH_DELAY_V:
.word 0x9999
SRAM_STACK_V:
.word 0xD2800600
DDR_07_V:
.word 0xfc60001c
DDR_ACTIVE_V:
.word 0x01000000
DDR_57_V:
.word 0xfc6000e4
CYCLES_MASK_V:
.word 0xffff0000
REFRESH_CYCLES_V:
.word 0xf0f0
SREFRESH_MASK_V:
.word 0x00010000
.global setfreq_sz
setfreq_sz:
.word setfreq_sz - setfreq