WSL2-Linux-Kernel/arch/cris/arch-v32/mach-a3/dram_init.S

119 строки
2.9 KiB
ArmAsm

/*
* DDR SDRAM initialization - alter with care
* This file is intended to be included from other assembler files
*
* Note: This file may not modify r8 or r9 because they are used to
* carry information from the decompressor to the kernel
*
* Copyright (C) 2005-2007 Axis Communications AB
*
* Authors: Mikael Starvik <starvik@axis.com>
*/
/* Just to be certain the config file is included, we include it here
* explicitly instead of depending on it being included in the file that
* uses this code.
*/
#include <hwregs/asm/reg_map_asm.h>
#include <hwregs/asm/ddr2_defs_asm.h>
;; WARNING! The registers r8 and r9 are used as parameters carrying
;; information from the decompressor (if the kernel was compressed).
;; They should not be used in the code below.
;; Refer to ddr2 MDS for initialization sequence
; 2. Wait 200us
move.d 10000, $r2
1: bne 1b
subq 1, $r2
; Start clock
move.d REG_ADDR(ddr2, regi_ddr2_ctrl, rw_phy_cfg), $r0
move.d REG_STATE(ddr2, rw_phy_cfg, en, yes), $r1
move.d $r1, [$r0]
; 2. Wait 200us
move.d 10000, $r2
1: bne 1b
subq 1, $r2
; Reset phy and start calibration
move.d REG_ADDR(ddr2, regi_ddr2_ctrl, rw_phy_ctrl), $r0
move.d REG_STATE(ddr2, rw_phy_ctrl, rst, yes) | \
REG_STATE(ddr2, rw_phy_ctrl, cal_rst, yes), $r1
move.d $r1, [$r0]
move.d REG_STATE(ddr2, rw_phy_ctrl, cal_start, yes), $r1
move.d $r1, [$r0]
; 2. Wait 200us
move.d 10000, $r2
1: bne 1b
subq 1, $r2
; Issue commands
move.d REG_ADDR(ddr2, regi_ddr2_ctrl, rw_ctrl), $r0
move.d sdram_commands_start, $r2
command_loop:
movu.b [$r2+], $r1
movu.w [$r2+], $r3
do_cmd:
lslq 16, $r1
or.d $r3, $r1
move.d $r1, [$r0]
; 2. Wait 200us
move.d 10000, $r4
1: bne 1b
subq 1, $r4
cmp.d sdram_commands_end, $r2
blo command_loop
nop
; Set timing
move.d REG_ADDR(ddr2, regi_ddr2_ctrl, rw_timing), $r0
move.d CONFIG_ETRAX_DDR2_TIMING, $r1
move.d $r1, [$r0]
; Set latency
move.d REG_ADDR(ddr2, regi_ddr2_ctrl, rw_latency), $r0
move.d CONFIG_ETRAX_DDR2_LATENCY, $r1
move.d $r1, [$r0]
; Set configuration
move.d REG_ADDR(ddr2, regi_ddr2_ctrl, rw_cfg), $r0
move.d CONFIG_ETRAX_DDR2_CONFIG, $r1
move.d $r1, [$r0]
ba after_sdram_commands
nop
sdram_commands_start:
.byte regk_ddr2_deselect
.word 0
.byte regk_ddr2_pre
.word regk_ddr2_pre_all
.byte regk_ddr2_emrs2
.word 0
.byte regk_ddr2_emrs3
.word 0
.byte regk_ddr2_emrs
.word regk_ddr2_dll_en
.byte regk_ddr2_mrs
.word regk_ddr2_dll_rst
.byte regk_ddr2_pre
.word regk_ddr2_pre_all
.byte regk_ddr2_ref
.word 0
.byte regk_ddr2_ref
.word 0
.byte regk_ddr2_mrs
.word CONFIG_ETRAX_DDR2_MRS & 0xffff
.byte regk_ddr2_emrs
.word regk_ddr2_ocd_default | regk_ddr2_dll_en
.byte regk_ddr2_emrs
.word regk_ddr2_ocd_exit | regk_ddr2_dll_en | (CONFIG_ETRAX_DDR2_MRS >> 16)
sdram_commands_end:
.align 1
after_sdram_commands: