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Diffstat (limited to 'board/omap2420h4/lowlevel_init.S')
| -rwxr-xr-x | board/omap2420h4/lowlevel_init.S | 185 |
1 files changed, 185 insertions, 0 deletions
diff --git a/board/omap2420h4/lowlevel_init.S b/board/omap2420h4/lowlevel_init.S new file mode 100755 index 0000000..9752fc4 --- /dev/null +++ b/board/omap2420h4/lowlevel_init.S @@ -0,0 +1,185 @@ +/* + * Board specific setup info + * + * (C) Copyright 2004 + * Texas Instruments, <www.ti.com> + * Richard Woodruff <r-woodruff2@ti.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., 59 Temple Place, Suite 330, Boston, + * MA 02111-1307 USA + */ + +#include <config.h> +#include <version.h> +#include <asm/arch/omap2420.h> +#include <asm/arch/mem.h> +#include <asm/arch/clocks.h> + +_TEXT_BASE: + .word TEXT_BASE /* sdram load addr from config.mk */ + +/************************************************************************** + * cpy_clk_code: relocates clock code into SRAM where its safer to execute + * R1 = SRAM destination address. + *************************************************************************/ +.global cpy_clk_code + cpy_clk_code: + /* Copy DPLL code into SRAM */ + adr r0, go_to_speed /* get addr of clock setting code */ + mov r2, #384 /* r2 size to copy (div by 32 bytes) */ + mov r1, r1 /* r1 <- dest address (passed in) */ + add r2, r2, r0 /* r2 <- source end address */ +next2: + ldmia r0!, {r3-r10} /* copy from source address [r0] */ + stmia r1!, {r3-r10} /* copy to target address [r1] */ + cmp r0, r2 /* until source end address [r2] */ + bne next2 + mov pc, lr /* back to caller */ + +/* **************************************************************************** + * go_to_speed: -Moves to bypass, -Commits clock dividers, -puts dpll at speed + * -executed from SRAM. + * R0 = PRCM_CLKCFG_CTRL - addr of valid reg + * R1 = CM_CLKEN_PLL - addr dpll ctlr reg + * R2 = dpll value + * R3 = CM_IDLEST_CKGEN - addr dpll lock wait + ******************************************************************************/ +.global go_to_speed + go_to_speed: + sub sp, sp, #0x4 /* get some stack space */ + str r4, [sp] /* save r4's value */ + + /* move into fast relock bypass */ + ldr r8, pll_ctl_add + mov r4, #0x2 + str r4, [r8] + ldr r4, pll_stat +block: + ldr r8, [r4] /* wait for bypass to take effect */ + and r8, r8, #0x3 + cmp r8, #0x1 + bne block + + /* set new dpll dividers _after_ in bypass */ + ldr r4, pll_div_add + ldr r8, pll_div_val + str r8, [r4] + + /* now prepare GPMC (flash) for new dpll speed */ + /* flash needs to be stable when we jump back to it */ + ldr r4, cfg3_0_addr + ldr r8, cfg3_0_val + str r8, [r4] + ldr r4, cfg4_0_addr + ldr r8, cfg4_0_val + str r8, [r4] + ldr r4, cfg1_0_addr + ldr r8, [r4] + orr r8, r8, #0x3 /* up gpmc divider */ + str r8, [r4] + + /* setup to 2x loop though code. The first loop pre-loads the + * icache, the 2nd commits the prcm config, and locks the dpll + */ + mov r4, #0x1000 /* spin spin spin */ + mov r8, #0x4 /* first pass condition & set registers */ + cmp r8, #0x4 +2: + ldrne r8, [r3] /* DPLL lock check */ + and r8, r8, #0x7 + cmp r8, #0x2 + beq 4f +3: + subeq r8, r8, #0x1 + streq r8, [r0] /* commit dividers (2nd time) */ + nop +lloop1: + sub r4, r4, #0x1 /* Loop currently necessary else bad jumps */ + nop + cmp r4, #0x0 + bne lloop1 + mov r4, #0x40000 + cmp r8, #0x1 + nop + streq r2, [r1] /* lock dpll (2nd time) */ + nop +lloop2: + sub r4, r4, #0x1 /* loop currently necessary else bad jumps */ + nop + cmp r4, #0x0 + bne lloop2 + mov r4, #0x40000 + cmp r8, #0x1 + nop + ldreq r8, [r3] /* get lock condition for dpll */ + cmp r8, #0x4 /* first time though? */ + bne 2b + moveq r8, #0x2 /* set to dpll check condition. */ + beq 3b /* if condition not true branch */ +4: + ldr r4, [sp] + add sp, sp, #0x4 /* return stack space */ + mov pc, lr /* back to caller, locked */ + +_go_to_speed: .word go_to_speed + +/* these constants need to be close for PIC code */ +cfg3_0_addr: + .word GPMC_CONFIG3_0 +cfg3_0_val: + .word H4_24XX_GPMC_CONFIG3_0 +cfg4_0_addr: + .word GPMC_CONFIG4_0 +cfg4_0_val: + .word H4_24XX_GPMC_CONFIG4_0 +cfg1_0_addr: + .word GPMC_CONFIG1_0 +pll_ctl_add: + .word CM_CLKEN_PLL +pll_stat: + .word CM_IDLEST_CKGEN +pll_div_add: + .word CM_CLKSEL1_PLL +pll_div_val: + .word DPLL_VAL /* DPLL setting (300MHz default) */ + +.globl lowlevel_init +lowlevel_init: + ldr sp, SRAM_STACK + str ip, [sp] /* stash old link register */ + mov ip, lr /* save link reg across call */ + bl s_init /* go setup pll,mux,memory */ + ldr ip, [sp] /* restore save ip */ + mov lr, ip /* restore link reg */ + + /* map interrupt controller */ + ldr r0, VAL_INTH_SETUP + mcr p15, 0, r0, c15, c2, 4 + + /* back to arch calling code */ + mov pc, lr + + /* the literal pools origin */ + .ltorg + +REG_CONTROL_STATUS: + .word CONTROL_STATUS +VAL_INTH_SETUP: + .word PERIFERAL_PORT_BASE +SRAM_STACK: + .word LOW_LEVEL_SRAM_STACK |