| 1 | /* |
| 2 | * nand_read.c: Simple NAND read functions for booting from NAND |
| 3 | * |
| 4 | * This is used by cpu/arm920/start.S assembler code, |
| 5 | * and the board-specific linker script must make sure this |
| 6 | * file is linked within the first 4kB of NAND flash. |
| 7 | * |
| 8 | * Taken from GPLv2 licensed vivi bootloader, |
| 9 | * Copyright (C) 2002 MIZI Research, Inc. |
| 10 | * |
| 11 | * Author: Hwang, Chideok <hwang@mizi.com> |
| 12 | * Date : $Date: 2004/02/04 10:37:37 $ |
| 13 | * |
| 14 | * u-boot integration and bad-block skipping (C) 2006 by OpenMoko, Inc. |
| 15 | * Author: Harald Welte <laforge@openmoko.org> |
| 16 | */ |
| 17 | |
| 18 | /* NOTE this stuff runs in steppingstone context! */ |
| 19 | |
| 20 | /* the API refers to 512-byte blocks */ |
| 21 | |
| 22 | #include <qi.h> |
| 23 | #include "nand_read.h" |
| 24 | |
| 25 | #define NAND_CMD_READ0 0 |
| 26 | #define NAND_CMD_READSTART 0x30 |
| 27 | |
| 28 | #define __REGb(x) (*(volatile unsigned char *)(x)) |
| 29 | #define __REGw(x) (*(volatile unsigned short *)(x)) |
| 30 | #define __REGi(x) (*(volatile unsigned int *)(x)) |
| 31 | #define NF_BASE 0x4e000000 |
| 32 | #define NFCONF __REGi(NF_BASE + 0x0) |
| 33 | #define NFCONT __REGi(NF_BASE + 0x4) |
| 34 | #define NFCMD __REGb(NF_BASE + 0x8) |
| 35 | #define NFADDR __REGb(NF_BASE + 0xc) |
| 36 | #define NFDATA __REGb(NF_BASE + 0x10) |
| 37 | #define NFDATA16 __REGw(NF_BASE + 0x10) |
| 38 | #define NFSTAT __REGb(NF_BASE + 0x20) |
| 39 | #define NFSTAT_BUSY 1 |
| 40 | #define nand_select() (NFCONT &= ~(1 << 1)) |
| 41 | #define nand_deselect() (NFCONT |= (1 << 1)) |
| 42 | #define nand_clear_RnB() (NFSTAT |= (1 << 2)) |
| 43 | |
| 44 | static inline void nand_wait(void) |
| 45 | { |
| 46 | int i; |
| 47 | |
| 48 | while (!(NFSTAT & NFSTAT_BUSY)) |
| 49 | for (i=0; i<10; i++); |
| 50 | } |
| 51 | |
| 52 | /* configuration for 2440 with 2048byte sized flash */ |
| 53 | #define NAND_5_ADDR_CYCLE |
| 54 | #define NAND_PAGE_SIZE 2048 |
| 55 | #define BAD_BLOCK_OFFSET NAND_PAGE_SIZE |
| 56 | #define NAND_BLOCK_MASK (NAND_PAGE_SIZE - 1) |
| 57 | #define NAND_BLOCK_SIZE (NAND_PAGE_SIZE * 64) |
| 58 | |
| 59 | int s3c2442_nand_is_bad_block(unsigned long block_index) |
| 60 | { |
| 61 | unsigned char data; |
| 62 | unsigned long page_num; |
| 63 | |
| 64 | nand_select(); |
| 65 | nand_clear_RnB(); |
| 66 | page_num = block_index >> 2; /* addr / 2048 */ |
| 67 | NFCMD = NAND_CMD_READ0; |
| 68 | NFADDR = BAD_BLOCK_OFFSET & 0xff; |
| 69 | NFADDR = (BAD_BLOCK_OFFSET >> 8) & 0xff; |
| 70 | NFADDR = page_num & 0xff; |
| 71 | NFADDR = (page_num >> 8) & 0xff; |
| 72 | NFADDR = (page_num >> 16) & 0xff; |
| 73 | NFCMD = NAND_CMD_READSTART; |
| 74 | nand_wait(); |
| 75 | data = (NFDATA & 0xff); |
| 76 | |
| 77 | if (data != 0xff) |
| 78 | return 1; |
| 79 | |
| 80 | return 0; |
| 81 | } |
| 82 | |
| 83 | static int nand_read_page_ll(unsigned char *buf, unsigned long block512, int blocks512) |
| 84 | { |
| 85 | unsigned short *ptr16 = (unsigned short *)buf; |
| 86 | unsigned int i, page_num; |
| 87 | unsigned int block_amount; |
| 88 | int blocks_possible = (3 - (block512 & 3)) + 1; |
| 89 | |
| 90 | |
| 91 | if (blocks512 > blocks_possible) |
| 92 | blocks512 = blocks_possible; |
| 93 | |
| 94 | block_amount = (NAND_PAGE_SIZE / 4 / 2) * blocks512; |
| 95 | |
| 96 | nand_clear_RnB(); |
| 97 | |
| 98 | NFCMD = NAND_CMD_READ0; |
| 99 | |
| 100 | page_num = block512 >> 2; /* 512 block -> 2048 block */ |
| 101 | /* Write Address */ |
| 102 | NFADDR = 0; |
| 103 | NFADDR = (block512 & 3) << 1; /* which 512 block in 2048 */ |
| 104 | NFADDR = page_num & 0xff; |
| 105 | NFADDR = (page_num >> 8) & 0xff; |
| 106 | NFADDR = (page_num >> 16) & 0xff; |
| 107 | NFCMD = NAND_CMD_READSTART; |
| 108 | nand_wait(); |
| 109 | |
| 110 | for (i = 0; i < block_amount; i++) |
| 111 | *ptr16++ = NFDATA16; |
| 112 | |
| 113 | return blocks512; |
| 114 | } |
| 115 | |
| 116 | |
| 117 | /* low level nand read function */ |
| 118 | int nand_read_ll(unsigned char *buf, unsigned long start_block512, |
| 119 | int blocks512) |
| 120 | { |
| 121 | int i, j; |
| 122 | |
| 123 | /* chip Enable */ |
| 124 | nand_select(); |
| 125 | nand_clear_RnB(); |
| 126 | |
| 127 | for (i = 0; i < 10; i++) |
| 128 | ; |
| 129 | |
| 130 | while (blocks512 > 0) { |
| 131 | if (s3c2442_nand_is_bad_block(start_block512)) { |
| 132 | start_block512 += 4; |
| 133 | if (start_block512 >> 2 > BAD_BLOCK_OFFSET) |
| 134 | /* end of NAND */ |
| 135 | return -1; |
| 136 | continue; |
| 137 | } |
| 138 | |
| 139 | j = nand_read_page_ll(buf, start_block512, blocks512); |
| 140 | start_block512 += j; |
| 141 | buf += j << 9; |
| 142 | blocks512 -= j; |
| 143 | |
| 144 | if (this_board->get_ui_keys) |
| 145 | if ((this_board->get_ui_keys)() & UI_ACTION_SKIPKERNEL) { |
| 146 | puts(" ** skipping \n"); |
| 147 | return -3; |
| 148 | } |
| 149 | } |
| 150 | |
| 151 | /* chip Disable */ |
| 152 | nand_deselect(); |
| 153 | |
| 154 | return 0; |
| 155 | } |
| 156 | |
| 157 | |
