| wdenk | b02744a | 2003-04-05 00:53:31 +0000 | [diff] [blame] | 1 | /* |
| 2 | * Copyright (C) 2001, 2002 ETC s.r.o. |
| 3 | * |
| 4 | * This program is free software; you can redistribute it and/or |
| 5 | * modify it under the terms of the GNU General Public License |
| 6 | * as published by the Free Software Foundation; either version 2 |
| 7 | * of the License, or (at your option) any later version. |
| wdenk | 57b2d80 | 2003-06-27 21:31:46 +0000 | [diff] [blame] | 8 | * |
| wdenk | b02744a | 2003-04-05 00:53:31 +0000 | [diff] [blame] | 9 | * This program is distributed in the hope that it will be useful, |
| 10 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 11 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 12 | * GNU General Public License for more details. |
| wdenk | 57b2d80 | 2003-06-27 21:31:46 +0000 | [diff] [blame] | 13 | * |
| wdenk | b02744a | 2003-04-05 00:53:31 +0000 | [diff] [blame] | 14 | * You should have received a copy of the GNU General Public License |
| 15 | * along with this program; if not, write to the Free Software |
| 16 | * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA |
| 17 | * 02111-1307, USA. |
| wdenk | 57b2d80 | 2003-06-27 21:31:46 +0000 | [diff] [blame] | 18 | * |
| wdenk | b02744a | 2003-04-05 00:53:31 +0000 | [diff] [blame] | 19 | * Written by Marcel Telka <marcel@telka.sk>, 2001, 2002. |
| 20 | * Changes for U-Boot Peter Figuli <peposh@etc.sk>, 2003. |
| 21 | * |
| 22 | * This file is taken from OpenWinCE project hosted by SourceForge.net |
| 23 | * |
| 24 | * Documentation: |
| 25 | * [1] Intel Corporation, "Intel PXA250 and PXA210 Application Processors |
| 26 | * Developer's Manual", February 2002, Order Number: 278522-001 |
| 27 | * [2] Samsung Electronics, "8Mx16 SDRAM 54CSP K4S281633D-RL/N/P", |
| 28 | * Revision 1.0, February 2002 |
| 29 | * [3] Samsung Electronics, "16Mx16 SDRAM 54CSP K4S561633C-RL(N)", |
| 30 | * Revision 1.0, February 2002 |
| wdenk | 57b2d80 | 2003-06-27 21:31:46 +0000 | [diff] [blame] | 31 | * |
| wdenk | b02744a | 2003-04-05 00:53:31 +0000 | [diff] [blame] | 32 | */ |
| 33 | |
| 34 | #include <config.h> |
| 35 | #include <version.h> |
| 36 | #include <asm/arch/pxa-regs.h> |
| 37 | |
| wdenk | 336b2bc | 2005-04-02 23:52:25 +0000 | [diff] [blame] | 38 | .globl lowlevel_init |
| 39 | lowlevel_init: |
| wdenk | b02744a | 2003-04-05 00:53:31 +0000 | [diff] [blame] | 40 | |
| 41 | mov r10, lr |
| 42 | |
| 43 | /* setup memory - see 6.12 in [1] |
| 44 | * Step 1 - wait 200 us |
| 45 | */ |
| 46 | mov r0,#0x2700 /* wait 200 us @ 99.5 MHz */ |
| 47 | 1: subs r0, r0, #1 |
| 48 | bne 1b |
| 49 | /* TODO: complete step 1 for Synchronous Static memory*/ |
| 50 | |
| 51 | ldr r0, =0x48000000 /* MC_BASE */ |
| 52 | |
| 53 | |
| wdenk | b02744a | 2003-04-05 00:53:31 +0000 | [diff] [blame] | 54 | /* step 1.a - setup MSCx |
| 55 | */ |
| 56 | ldr r1, =0x000012B3 /* MSC0_RRR0(1) | MSC0_RDN0(2) | MSC0_RDF0(11) | MSC0_RT0(3) */ |
| 57 | str r1, [r0, #0x8] /* MSC0_OFFSET */ |
| 58 | |
| 59 | /* step 1.c - clear MDREFR:K1FREE, set MDREFR:DRI |
| 60 | * see AUTO REFRESH chapter in section D. in [2] and in [3] |
| 61 | * DRI = (64ms / 4096) * 99.53MHz / 32 = 48 for K4S281633 |
| 62 | * DRI = (64ms / 8192) * 99.52MHz / 32 = 24 for K4S561633 |
| 63 | * TODO: complete for Synchronous Static memory |
| 64 | */ |
| 65 | ldr r1, [r0, #4] /* MDREFR_OFFSET */ |
| 66 | ldr r2, =0x01000FFF /* MDREFR_K1FREE | MDREFR_DRI_MASK */ |
| 67 | bic r1, r1, r2 |
| 68 | #if defined( WEP_SDRAM_K4S281633 ) |
| 69 | orr r1, r1, #48 /* MDREFR_DRI(48) */ |
| 70 | #elif defined( WEP_SDRAM_K4S561633 ) |
| 71 | orr r1, r1, #24 /* MDREFR_DRI(24) */ |
| 72 | #else |
| 73 | #error SDRAM chip is not defined |
| 74 | #endif |
| 75 | |
| 76 | str r1, [r0, #4] /* MDREFR_OFFSET */ |
| 77 | |
| 78 | /* Step 2 - only for Synchronous Static memory (TODO) |
| 79 | * |
| 80 | * Step 3 - same as step 4 |
| 81 | * |
| 82 | * Step 4 |
| 83 | * |
| 84 | * Step 4.a - set MDREFR:K1RUN, clear MDREFR:K1DB2 |
| 85 | */ |
| 86 | orr r1, r1, #0x00010000 /* MDREFR_K1RUN */ |
| 87 | bic r1, r1, #0x00020000 /* MDREFR_K1DB2 */ |
| 88 | str r1, [r0, #4] /* MDREFR_OFFSET */ |
| 89 | |
| 90 | /* Step 4.b - clear MDREFR:SLFRSH */ |
| 91 | bic r1, r1, #0x00400000 /* MDREFR_SLFRSH */ |
| 92 | str r1, [r0, #4] /* MDREFR_OFFSET */ |
| 93 | |
| 94 | /* Step 4.c - set MDREFR:E1PIN */ |
| 95 | orr r1, r1, #0x00008000 /* MDREFR_E1PIN */ |
| 96 | str r1, [r0, #4] /* MDREFR_OFFSET */ |
| 97 | |
| 98 | /* Step 4.d - automatically done |
| 99 | * |
| 100 | * Steps 4.e and 4.f - configure SDRAM |
| 101 | */ |
| 102 | #if defined( WEP_SDRAM_K4S281633 ) |
| 103 | ldr r1, =0x00000AA8 /* MDCNFG_DTC0(2) | MDCNFG_DLATCH0 | MDCNFG_DCAC0(1) | MDCNFG_DRAC0(1) | MDCNFG_DNB0 */ |
| 104 | #elif defined( WEP_SDRAM_K4S561633 ) |
| 105 | ldr r1, =0x00000AC8 /* MDCNFG_DTC0(2) | MDCNFG_DLATCH0 | MDCNFG_DCAC0(1) | MDCNFG_DRAC0(2) | MDCNFG_DNB0 */ |
| 106 | #else |
| 107 | #error SDRAM chip is not defined |
| 108 | #endif |
| 109 | str r1, [r0, #0] /* MDCNFG_OFFSET */ |
| 110 | |
| 111 | /* Step 5 - wait at least 200 us for SDRAM |
| 112 | * see section B. in [2] |
| 113 | */ |
| 114 | mov r2,#0x2700 /* wait 200 us @ 99.5 MHz */ |
| 115 | 1: subs r2, r2, #1 |
| 116 | bne 1b |
| 117 | |
| 118 | /* Step 6 - after reset dcache is disabled, so automatically done |
| 119 | * |
| 120 | * Step 7 - eight refresh cycles |
| 121 | */ |
| 122 | mov r2, #0xA0000000 |
| 123 | ldr r3, [r2] |
| 124 | ldr r3, [r2] |
| 125 | ldr r3, [r2] |
| 126 | ldr r3, [r2] |
| 127 | ldr r3, [r2] |
| 128 | ldr r3, [r2] |
| 129 | ldr r3, [r2] |
| 130 | ldr r3, [r2] |
| 131 | |
| 132 | /* Step 8 - we don't need dcache now |
| 133 | * |
| 134 | * Step 9 - enable SDRAM partition 0 |
| 135 | */ |
| 136 | orr r1, r1, #1 /* MDCNFG_DE0 */ |
| 137 | str r1, [r0, #0] /* MDCNFG_OFFSET */ |
| 138 | |
| 139 | /* Step 10 - write MDMRS */ |
| 140 | mov r1, #0 |
| 141 | str r1, [r0, #0x40] /* MDMRS_OFFSET */ |
| 142 | |
| 143 | /* Step 11 - optional (TODO) */ |
| 144 | |
| 145 | mov pc,r10 |