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u-boot/arch/arm/mach-orion5x/lowlevel_init.S
Mans Rullgard 66a00be287 ARM: orion5x: fix use of callee-saved registers in lowloevel_init
The lowlevel_init function uses r4 and r6 without preserving their
values as required by the AAPCS.  Use r0 and r2 instead as these
are call-clobbered.

Signed-off-by: Mans Rullgard <mans@mansr.com>
Reviewed-by: Chris Packham <judge.packham@gmail.com>
2018-06-07 09:12:26 -04:00

286 lines
7.2 KiB
ArmAsm

/* SPDX-License-Identifier: GPL-2.0+ */
/*
* Copyright (C) 2010 Albert ARIBAUD <albert.u.boot@aribaud.net>
*
* (C) Copyright 2009
* Marvell Semiconductor <www.marvell.com>
* Written-by: Prafulla Wadaskar <prafulla@marvell.com>
*/
#include <config.h>
#include "asm/arch/orion5x.h"
/*
* Configuration values for SDRAM access setup
*/
#define SDRAM_CONFIG 0x3148400
#define SDRAM_MODE 0x62
#define SDRAM_CONTROL 0x4041000
#define SDRAM_TIME_CTRL_LOW 0x11602220
#define SDRAM_TIME_CTRL_HI 0x40c
#define SDRAM_OPEN_PAGE_EN 0x0
/* DDR 1 2x 32M NANYA NT5DS16M16CS-6K ==> 64MB */
#define SDRAM_BANK0_SIZE 0x3ff0001
#define SDRAM_ADDR_CTRL 0x10
#define SDRAM_OP_NOP 0x05
#define SDRAM_OP_SETMODE 0x03
#define SDRAM_PAD_CTRL_WR_EN 0x80000000
#define SDRAM_PAD_CTRL_TUNE_EN 0x00010000
#define SDRAM_PAD_CTRL_DRVN_MASK 0x0000003f
#define SDRAM_PAD_CTRL_DRVP_MASK 0x00000fc0
/*
* For Guideline MEM-3 - Drive Strength value
*/
#define DDR1_PAD_STRENGTH_DEFAULT 0x00001000
#define SDRAM_PAD_CTRL_DRV_STR_MASK 0x00003000
/*
* For Guideline MEM-4 - DQS Reference Delay Tuning
*/
#define MSAR_ARMDDRCLCK_MASK 0x000000f0
#define MSAR_ARMDDRCLCK_H_MASK 0x00000100
#define MSAR_ARMDDRCLCK_333_167 0x00000000
#define MSAR_ARMDDRCLCK_500_167 0x00000030
#define MSAR_ARMDDRCLCK_667_167 0x00000060
#define MSAR_ARMDDRCLCK_400_200_1 0x000001E0
#define MSAR_ARMDDRCLCK_400_200 0x00000010
#define MSAR_ARMDDRCLCK_600_200 0x00000050
#define MSAR_ARMDDRCLCK_800_200 0x00000070
#define FTDLL_DDR1_166MHZ 0x0047F001
#define FTDLL_DDR1_200MHZ 0x0044D001
/*
* Low-level init happens right after start.S has switched to SVC32,
* flushed and disabled caches and disabled MMU. We're still running
* from the boot chip select, so the first thing SPL should do is to
* set up the RAM to copy U-Boot into.
*/
.globl lowlevel_init
lowlevel_init:
#ifdef CONFIG_SPL_BUILD
/* Use 'r2 as the base for internal register accesses */
ldr r2, =ORION5X_REGS_PHY_BASE
/* move internal registers from the default 0xD0000000
* to their intended location, defined by SoC */
ldr r3, =0xD0000000
add r3, r3, #0x20000
str r2, [r3, #0x80]
/* Use R3 as the base for DRAM registers */
add r3, r2, #0x01000
/*DDR SDRAM Initialization Control */
ldr r0, =0x00000001
str r0, [r3, #0x480]
/* Use R3 as the base for PCI registers */
add r3, r2, #0x31000
/* Disable arbiter */
ldr r0, =0x00000030
str r0, [r3, #0xd00]
/* Use R3 as the base for DRAM registers */
add r3, r2, #0x01000
/* set all dram windows to 0 */
mov r0, #0
str r0, [r3, #0x504]
str r0, [r3, #0x50C]
str r0, [r3, #0x514]
str r0, [r3, #0x51C]
/* 1) Configure SDRAM */
ldr r0, =SDRAM_CONFIG
str r0, [r3, #0x400]
/* 2) Set SDRAM Control reg */
ldr r0, =SDRAM_CONTROL
str r0, [r3, #0x404]
/* 3) Write SDRAM address control register */
ldr r0, =SDRAM_ADDR_CTRL
str r0, [r3, #0x410]
/* 4) Write SDRAM bank 0 size register */
ldr r0, =SDRAM_BANK0_SIZE
str r0, [r3, #0x504]
/* keep other banks disabled */
/* 5) Write SDRAM open pages control register */
ldr r0, =SDRAM_OPEN_PAGE_EN
str r0, [r3, #0x414]
/* 6) Write SDRAM timing Low register */
ldr r0, =SDRAM_TIME_CTRL_LOW
str r0, [r3, #0x408]
/* 7) Write SDRAM timing High register */
ldr r0, =SDRAM_TIME_CTRL_HI
str r0, [r3, #0x40C]
/* 8) Write SDRAM mode register */
/* The CPU must not attempt to change the SDRAM Mode register setting */
/* prior to DRAM controller completion of the DRAM initialization */
/* sequence. To guarantee this restriction, it is recommended that */
/* the CPU sets the SDRAM Operation register to NOP command, performs */
/* read polling until the register is back in Normal operation value, */
/* and then sets SDRAM Mode register to its new value. */
/* 8.1 write 'nop' to SDRAM operation */
ldr r0, =SDRAM_OP_NOP
str r0, [r3, #0x418]
/* 8.2 poll SDRAM operation until back in 'normal' mode. */
1:
ldr r0, [r3, #0x418]
cmp r0, #0
bne 1b
/* 8.3 Now its safe to write new value to SDRAM Mode register */
ldr r0, =SDRAM_MODE
str r0, [r3, #0x41C]
/* 8.4 Set new mode */
ldr r0, =SDRAM_OP_SETMODE
str r0, [r3, #0x418]
/* 8.5 poll SDRAM operation until back in 'normal' mode. */
2:
ldr r0, [r3, #0x418]
cmp r0, #0
bne 2b
/* DDR SDRAM Address/Control Pads Calibration */
ldr r0, [r3, #0x4C0]
/* Set Bit [31] to make the register writable */
orr r0, r0, #SDRAM_PAD_CTRL_WR_EN
str r0, [r3, #0x4C0]
bic r0, r0, #SDRAM_PAD_CTRL_WR_EN
bic r0, r0, #SDRAM_PAD_CTRL_TUNE_EN
bic r0, r0, #SDRAM_PAD_CTRL_DRVN_MASK
bic r0, r0, #SDRAM_PAD_CTRL_DRVP_MASK
/* Get the final N locked value of driving strength [22:17] */
mov r1, r0
mov r1, r1, LSL #9
mov r1, r1, LSR #26 /* r1[5:0]<DrvN> = r3[22:17]<LockN> */
orr r1, r1, r1, LSL #6 /* r1[11:6]<DrvP> = r1[5:0]<DrvN> */
/* Write to both <DrvN> bits [5:0] and <DrvP> bits [11:6] */
orr r0, r0, r1
str r0, [r3, #0x4C0]
/* DDR SDRAM Data Pads Calibration */
ldr r0, [r3, #0x4C4]
/* Set Bit [31] to make the register writable */
orr r0, r0, #SDRAM_PAD_CTRL_WR_EN
str r0, [r3, #0x4C4]
bic r0, r0, #SDRAM_PAD_CTRL_WR_EN
bic r0, r0, #SDRAM_PAD_CTRL_TUNE_EN
bic r0, r0, #SDRAM_PAD_CTRL_DRVN_MASK
bic r0, r0, #SDRAM_PAD_CTRL_DRVP_MASK
/* Get the final N locked value of driving strength [22:17] */
mov r1, r0
mov r1, r1, LSL #9
mov r1, r1, LSR #26
orr r1, r1, r1, LSL #6 /* r1[5:0] = r3[22:17]<LockN> */
/* Write to both <DrvN> bits [5:0] and <DrvP> bits [11:6] */
orr r0, r0, r1
str r0, [r3, #0x4C4]
/* Implement Guideline (GL# MEM-3) Drive Strength Value */
/* Relevant for: 88F5181-A1/B0/B1 and 88F5281-A0/B0 */
ldr r1, =DDR1_PAD_STRENGTH_DEFAULT
/* Enable writes to DDR SDRAM Addr/Ctrl Pads Calibration register */
ldr r0, [r3, #0x4C0]
orr r0, r0, #SDRAM_PAD_CTRL_WR_EN
str r0, [r3, #0x4C0]
/* Correct strength and disable writes again */
bic r0, r0, #SDRAM_PAD_CTRL_WR_EN
bic r0, r0, #SDRAM_PAD_CTRL_DRV_STR_MASK
orr r0, r0, r1
str r0, [r3, #0x4C0]
/* Enable writes to DDR SDRAM Data Pads Calibration register */
ldr r0, [r3, #0x4C4]
orr r0, r0, #SDRAM_PAD_CTRL_WR_EN
str r0, [r3, #0x4C4]
/* Correct strength and disable writes again */
bic r0, r0, #SDRAM_PAD_CTRL_DRV_STR_MASK
bic r0, r0, #SDRAM_PAD_CTRL_WR_EN
orr r0, r0, r1
str r0, [r3, #0x4C4]
/* Implement Guideline (GL# MEM-4) DQS Reference Delay Tuning */
/* Relevant for: 88F5181-A1/B0/B1 and 88F5281-A0/B0 */
/* Get the "sample on reset" register for the DDR frequancy */
ldr r3, =0x10000
ldr r0, [r3, #0x010]
ldr r1, =MSAR_ARMDDRCLCK_MASK
and r1, r0, r1
ldr r0, =FTDLL_DDR1_166MHZ
cmp r1, #MSAR_ARMDDRCLCK_333_167
beq 3f
cmp r1, #MSAR_ARMDDRCLCK_500_167
beq 3f
cmp r1, #MSAR_ARMDDRCLCK_667_167
beq 3f
ldr r0, =FTDLL_DDR1_200MHZ
cmp r1, #MSAR_ARMDDRCLCK_400_200_1
beq 3f
cmp r1, #MSAR_ARMDDRCLCK_400_200
beq 3f
cmp r1, #MSAR_ARMDDRCLCK_600_200
beq 3f
cmp r1, #MSAR_ARMDDRCLCK_800_200
beq 3f
ldr r0, =0
3:
/* Use R3 as the base for DRAM registers */
add r3, r2, #0x01000
ldr r2, [r3, #0x484]
orr r2, r2, r0
str r2, [r3, #0x484]
/* enable for 2 GB DDR; detection should find out real amount */
sub r0, r0, r0
str r0, [r3, #0x500]
ldr r0, =0x7fff0001
str r0, [r3, #0x504]
#endif /* CONFIG_SPL_BUILD */
/* Return to U-Boot via saved link register */
mov pc, lr