diff options
Diffstat (limited to 'arch/arm/cpu/arm926ejs/orion5x/lowlevel_init.S')
-rw-r--r-- | arch/arm/cpu/arm926ejs/orion5x/lowlevel_init.S | 293 |
1 files changed, 293 insertions, 0 deletions
diff --git a/arch/arm/cpu/arm926ejs/orion5x/lowlevel_init.S b/arch/arm/cpu/arm926ejs/orion5x/lowlevel_init.S new file mode 100644 index 0000000..b0e15f6 --- /dev/null +++ b/arch/arm/cpu/arm926ejs/orion5x/lowlevel_init.S @@ -0,0 +1,293 @@ +/* + * Copyright (C) 2010 Albert ARIBAUD <albert.aribaud@free.fr> + * + * (C) Copyright 2009 + * Marvell Semiconductor <www.marvell.com> + * Written-by: Prafulla Wadaskar <prafulla@marvell.com> + * + * See file CREDITS for list of people who contributed to this + * project. + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License as + * published by the Free Software Foundation; either version 2 of + * the License, or (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, + * MA 02110-1301 USA + */ + +#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 we should do is set + * up RAM for us to relocate into. + */ + +.globl lowlevel_init + +lowlevel_init: + + /* Use 'r4 as the base for internal register accesses */ + ldr r4, =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 r4, [r3, #0x80] + + /* Use R3 as the base for DRAM registers */ + add r3, r4, #0x01000 + + /*DDR SDRAM Initialization Control */ + ldr r6, =0x00000001 + str r6, [r3, #0x480] + + /* Use R3 as the base for PCI registers */ + add r3, r4, #0x31000 + + /* Disable arbiter */ + ldr r6, =0x00000030 + str r6, [r3, #0xd00] + + /* Use R3 as the base for DRAM registers */ + add r3, r4, #0x01000 + + /* set all dram windows to 0 */ + mov r6, #0 + str r6, [r3, #0x504] + str r6, [r3, #0x50C] + str r6, [r3, #0x514] + str r6, [r3, #0x51C] + + /* 1) Configure SDRAM */ + ldr r6, =SDRAM_CONFIG + str r6, [r3, #0x400] + + /* 2) Set SDRAM Control reg */ + ldr r6, =SDRAM_CONTROL + str r6, [r3, #0x404] + + /* 3) Write SDRAM address control register */ + ldr r6, =SDRAM_ADDR_CTRL + str r6, [r3, #0x410] + + /* 4) Write SDRAM bank 0 size register */ + ldr r6, =SDRAM_BANK0_SIZE + str r6, [r3, #0x504] + /* keep other banks disabled */ + + /* 5) Write SDRAM open pages control register */ + ldr r6, =SDRAM_OPEN_PAGE_EN + str r6, [r3, #0x414] + + /* 6) Write SDRAM timing Low register */ + ldr r6, =SDRAM_TIME_CTRL_LOW + str r6, [r3, #0x408] + + /* 7) Write SDRAM timing High register */ + ldr r6, =SDRAM_TIME_CTRL_HI + str r6, [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 r6, =SDRAM_OP_NOP + str r6, [r3, #0x418] + + /* 8.2 poll SDRAM operation until back in 'normal' mode. */ +1: + ldr r6, [r3, #0x418] + cmp r6, #0 + bne 1b + + /* 8.3 Now its safe to write new value to SDRAM Mode register */ + ldr r6, =SDRAM_MODE + str r6, [r3, #0x41C] + + /* 8.4 Set new mode */ + ldr r6, =SDRAM_OP_SETMODE + str r6, [r3, #0x418] + + /* 8.5 poll SDRAM operation until back in 'normal' mode. */ +2: + ldr r6, [r3, #0x418] + cmp r6, #0 + bne 2b + + /* DDR SDRAM Address/Control Pads Calibration */ + ldr r6, [r3, #0x4C0] + + /* Set Bit [31] to make the register writable */ + orr r6, r6, #SDRAM_PAD_CTRL_WR_EN + str r6, [r3, #0x4C0] + + bic r6, r6, #SDRAM_PAD_CTRL_WR_EN + bic r6, r6, #SDRAM_PAD_CTRL_TUNE_EN + bic r6, r6, #SDRAM_PAD_CTRL_DRVN_MASK + bic r6, r6, #SDRAM_PAD_CTRL_DRVP_MASK + + /* Get the final N locked value of driving strength [22:17] */ + mov r1, r6 + 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 r6, r6, r1 + str r6, [r3, #0x4C0] + + /* DDR SDRAM Data Pads Calibration */ + ldr r6, [r3, #0x4C4] + + /* Set Bit [31] to make the register writable */ + orr r6, r6, #SDRAM_PAD_CTRL_WR_EN + str r6, [r3, #0x4C4] + + bic r6, r6, #SDRAM_PAD_CTRL_WR_EN + bic r6, r6, #SDRAM_PAD_CTRL_TUNE_EN + bic r6, r6, #SDRAM_PAD_CTRL_DRVN_MASK + bic r6, r6, #SDRAM_PAD_CTRL_DRVP_MASK + + /* Get the final N locked value of driving strength [22:17] */ + mov r1, r6 + 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 r6, r6, r1 + + str r6, [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 r6, [r3, #0x4C0] + orr r6, r6, #SDRAM_PAD_CTRL_WR_EN + str r6, [r3, #0x4C0] + + /* Correct strength and disable writes again */ + bic r6, r6, #SDRAM_PAD_CTRL_WR_EN + bic r6, r6, #SDRAM_PAD_CTRL_DRV_STR_MASK + orr r6, r6, r1 + str r6, [r3, #0x4C0] + + /* Enable writes to DDR SDRAM Data Pads Calibration register */ + ldr r6, [r3, #0x4C4] + orr r6, r6, #SDRAM_PAD_CTRL_WR_EN + str r6, [r3, #0x4C4] + + /* Correct strength and disable writes again */ + bic r6, r6, #SDRAM_PAD_CTRL_DRV_STR_MASK + bic r6, r6, #SDRAM_PAD_CTRL_WR_EN + orr r6, r6, r1 + str r6, [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 r6, [r3, #0x010] + ldr r1, =MSAR_ARMDDRCLCK_MASK + and r1, r6, r1 + + ldr r6, =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 r6, =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 r6, =0 + +3: + /* Use R3 as the base for DRAM registers */ + add r3, r4, #0x01000 + + ldr r2, [r3, #0x484] + orr r2, r2, r6 + str r2, [r3, #0x484] + + /* Return to U-boot via saved link register */ + mov pc, lr |