diff options
Diffstat (limited to 'kernel/arch/cris/arch-v32/mach-a3/dram_init.S')
| -rw-r--r-- | kernel/arch/cris/arch-v32/mach-a3/dram_init.S | 118 |
1 files changed, 118 insertions, 0 deletions
diff --git a/kernel/arch/cris/arch-v32/mach-a3/dram_init.S b/kernel/arch/cris/arch-v32/mach-a3/dram_init.S new file mode 100644 index 000000000..ec8648be3 --- /dev/null +++ b/kernel/arch/cris/arch-v32/mach-a3/dram_init.S @@ -0,0 +1,118 @@ +/* + * 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 decompresser 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 + * explicitely 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: |