| 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_READOOB 0x50 |
| 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 NFCMD __REGb(NF_BASE + 0x4) |
| 34 | #define NFADDR __REGb(NF_BASE + 0x8) |
| 35 | #define NFDATA __REGb(NF_BASE + 0xc) |
| 36 | #define NFSTAT __REGb(NF_BASE + 0x10) |
| 37 | #define NFSTAT_BUSY 1 |
| 38 | #define nand_select() (NFCONF &= ~0x800) |
| 39 | #define nand_deselect() (NFCONF |= 0x800) |
| 40 | #define nand_clear_RnB() do {} while (0) |
| 41 | |
| 42 | |
| 43 | static inline void nand_wait(void) |
| 44 | { |
| 45 | int i; |
| 46 | |
| 47 | while (!(NFSTAT & NFSTAT_BUSY)) |
| 48 | for (i=0; i<10; i++); |
| 49 | } |
| 50 | |
| 51 | /* configuration for 2410 with 512byte sized flash */ |
| 52 | #define NAND_PAGE_SIZE 512 |
| 53 | #define BAD_BLOCK_OFFSET 5 |
| 54 | #define NAND_BLOCK_MASK (NAND_PAGE_SIZE - 1) |
| 55 | #define NAND_BLOCK_SIZE 0x4000 |
| 56 | |
| 57 | static int is_bad_block(unsigned long block_index) |
| 58 | { |
| 59 | unsigned char data; |
| 60 | |
| 61 | nand_clear_RnB(); |
| 62 | |
| 63 | NFCMD = NAND_CMD_READOOB; /* 0x50 */ |
| 64 | NFADDR = BAD_BLOCK_OFFSET & 0xf; |
| 65 | NFADDR = (block_index ) & 0xff; |
| 66 | NFADDR = (block_index >> 8 ) & 0xff; |
| 67 | NFADDR = (block_index >> 16) & 0xff; |
| 68 | |
| 69 | nand_wait(); |
| 70 | data = (NFDATA & 0xff); |
| 71 | |
| 72 | if (data != 0xff) |
| 73 | return 1; |
| 74 | |
| 75 | return 0; |
| 76 | } |
| 77 | |
| 78 | static int nand_read_page_ll(unsigned char *buf, unsigned long block512) |
| 79 | { |
| 80 | unsigned int i; |
| 81 | |
| 82 | nand_clear_RnB(); |
| 83 | |
| 84 | NFCMD = NAND_CMD_READ0; |
| 85 | |
| 86 | /* Write Address */ |
| 87 | NFADDR = 0; |
| 88 | NFADDR = (block512 ) & 0xff; |
| 89 | NFADDR = (block512 >> 8 ) & 0xff; |
| 90 | NFADDR = (block512 >> 16) & 0xff; |
| 91 | |
| 92 | nand_wait(); |
| 93 | |
| 94 | for (i = 0; i < NAND_PAGE_SIZE; i++) { |
| 95 | *buf = (NFDATA & 0xff); |
| 96 | buf++; |
| 97 | } |
| 98 | |
| 99 | return 1; |
| 100 | } |
| 101 | |
| 102 | /* low level nand read function */ |
| 103 | int nand_read_ll(unsigned char *buf, unsigned long start_block512, int blocks512) |
| 104 | { |
| 105 | int i, j; |
| 106 | int bad_count = 0; |
| 107 | |
| 108 | /* chip Enable */ |
| 109 | nand_select(); |
| 110 | nand_clear_RnB(); |
| 111 | |
| 112 | for (i = 0; i < 10; i++) |
| 113 | ; |
| 114 | |
| 115 | while (blocks512 > 0) { |
| 116 | if (is_bad_block(start_block512) || |
| 117 | is_bad_block(start_block512 + 1)) { |
| 118 | start_block512 += 1; |
| 119 | blocks512 += 1; |
| 120 | if (bad_count++ == 4) |
| 121 | return -1; |
| 122 | continue; |
| 123 | } |
| 124 | |
| 125 | j = nand_read_page_ll(buf, start_block512); |
| 126 | start_block512 += j; |
| 127 | buf += j << 9; |
| 128 | blocks512 -= j; |
| 129 | } |
| 130 | |
| 131 | /* chip Disable */ |
| 132 | nand_deselect(); |
| 133 | |
| 134 | return 0; |
| 135 | } |
| 136 | |
| 137 | |
