Newer
Older
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
/*
* SPL driver for Diskonchip G4 nand flash
*
* Copyright (C) 2013 Mike Dunn <mikedunn@newsguy.com>
*
* This file is released under the terms of GPL v2 and any later version.
* See the file COPYING in the root directory of the source tree for details.
*
*
* This driver basically mimics the load functionality of a typical IPL (initial
* program loader) resident in the 2k NOR-like region of the docg4 that is
* mapped to the reset vector. It allows the u-boot SPL to continue loading if
* the IPL loads a fixed number of flash blocks that is insufficient to contain
* the entire u-boot image. In this case, a concatenated spl + u-boot image is
* written at the flash offset from which the IPL loads an image, and when the
* IPL jumps to the SPL, the SPL resumes loading where the IPL left off. See
* the palmtreo680 for an example.
*
* This driver assumes that the data was written to the flash using the device's
* "reliable" mode, and also assumes that each 512 byte page is stored
* redundantly in the subsequent page. This storage format is likely to be used
* by all boards that boot from the docg4. The format compensates for the lack
* of ecc in the IPL.
*
* Reliable mode reduces the capacity of a block by half, and the redundant
* pages reduce it by half again. As a result, the normal 256k capacity of a
* block is reduced to 64k for the purposes of the IPL/SPL.
*/
#include <asm/io.h>
#include <linux/mtd/docg4.h>
/* forward declarations */
static inline void write_nop(void __iomem *docptr);
static int poll_status(void __iomem *docptr);
static void write_addr(void __iomem *docptr, uint32_t docg4_addr);
static void address_sequence(unsigned int g4_page, unsigned int g4_index,
void __iomem *docptr);
static int docg4_load_block_reliable(uint32_t flash_offset, void *dest_addr);
int nand_spl_load_image(uint32_t offs, unsigned int size, void *dst)
{
void *load_addr = dst;
uint32_t flash_offset = offs;
const unsigned int block_count =
(size + DOCG4_BLOCK_CAPACITY_SPL - 1)
/ DOCG4_BLOCK_CAPACITY_SPL;
int i;
for (i = 0; i < block_count; i++) {
int ret = docg4_load_block_reliable(flash_offset, load_addr);
if (ret)
return ret;
load_addr += DOCG4_BLOCK_CAPACITY_SPL;
flash_offset += DOCG4_BLOCK_SIZE;
}
return 0;
}
static inline void write_nop(void __iomem *docptr)
{
writew(0, docptr + DOC_NOP);
}
static int poll_status(void __iomem *docptr)
{
/*
* Busy-wait for the FLASHREADY bit to be set in the FLASHCONTROL
* register. Operations known to take a long time (e.g., block erase)
* should sleep for a while before calling this.
*/
uint8_t flash_status;
/* hardware quirk requires reading twice initially */
flash_status = readb(docptr + DOC_FLASHCONTROL);
do {
flash_status = readb(docptr + DOC_FLASHCONTROL);
} while (!(flash_status & DOC_CTRL_FLASHREADY));
return 0;
}
static void write_addr(void __iomem *docptr, uint32_t docg4_addr)
{
/* write the four address bytes packed in docg4_addr to the device */
writeb(docg4_addr & 0xff, docptr + DOC_FLASHADDRESS);
docg4_addr >>= 8;
writeb(docg4_addr & 0xff, docptr + DOC_FLASHADDRESS);
docg4_addr >>= 8;
writeb(docg4_addr & 0xff, docptr + DOC_FLASHADDRESS);
docg4_addr >>= 8;
writeb(docg4_addr & 0xff, docptr + DOC_FLASHADDRESS);
}
static void address_sequence(unsigned int g4_page, unsigned int g4_index,
void __iomem *docptr)
{
writew(DOCG4_SEQ_PAGE_READ, docptr + DOC_FLASHSEQUENCE);
writew(DOCG4_CMD_PAGE_READ, docptr + DOC_FLASHCOMMAND);
write_nop(docptr);
write_addr(docptr, ((uint32_t)g4_page << 16) | g4_index);
write_nop(docptr);
}
static int docg4_load_block_reliable(uint32_t flash_offset, void *dest_addr)
{
void __iomem *docptr = (void *)CONFIG_SYS_NAND_BASE;
unsigned int g4_page = flash_offset >> 11; /* 2k page */
const unsigned int last_g4_page = g4_page + 0x80; /* last in block */
int g4_index = 0;
uint16_t flash_status;
uint16_t *buf;
/* flash_offset must be aligned to the start of a block */
if (flash_offset & 0x3ffff)
return -1;
writew(DOC_SEQ_RESET, docptr + DOC_FLASHSEQUENCE);
writew(DOC_CMD_RESET, docptr + DOC_FLASHCOMMAND);
write_nop(docptr);
write_nop(docptr);
poll_status(docptr);
write_nop(docptr);
writew(0x45, docptr + DOC_FLASHSEQUENCE);
writew(0xa3, docptr + DOC_FLASHCOMMAND);
write_nop(docptr);
writew(0x22, docptr + DOC_FLASHCOMMAND);
write_nop(docptr);
/* read 1st 4 oob bytes of first subpage of block */
address_sequence(g4_page, 0x0100, docptr); /* index at oob */
write_nop(docptr);
flash_status = readw(docptr + DOC_FLASHCONTROL);
flash_status = readw(docptr + DOC_FLASHCONTROL);
if (flash_status & 0x06) /* sequence or protection errors */
return -1;
writew(DOCG4_CMD_READ2, docptr + DOC_FLASHCOMMAND);
write_nop(docptr);
write_nop(docptr);
poll_status(docptr);
writew(DOC_ECCCONF0_READ_MODE | 4, docptr + DOC_ECCCONF0);
write_nop(docptr);
write_nop(docptr);
write_nop(docptr);
write_nop(docptr);
write_nop(docptr);
/*
* Here we read the first four oob bytes of the first page of the block.
* The IPL on the palmtreo680 requires that this contain a 32 bit magic
* number, or the load aborts. We'll ignore it.
*/
readw(docptr + 0x103c); /* hw quirk; 1st read discarded */
readw(docptr + 0x103c); /* lower 16 bits of magic number */
readw(docptr + DOCG4_MYSTERY_REG); /* upper 16 bits of magic number */
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
writew(0, docptr + DOC_DATAEND);
write_nop(docptr);
write_nop(docptr);
/* load contents of block to memory */
buf = (uint16_t *)dest_addr;
do {
int i;
address_sequence(g4_page, g4_index, docptr);
writew(DOCG4_CMD_READ2,
docptr + DOC_FLASHCOMMAND);
write_nop(docptr);
write_nop(docptr);
poll_status(docptr);
writew(DOC_ECCCONF0_READ_MODE |
DOC_ECCCONF0_ECC_ENABLE |
DOCG4_BCH_SIZE,
docptr + DOC_ECCCONF0);
write_nop(docptr);
write_nop(docptr);
write_nop(docptr);
write_nop(docptr);
write_nop(docptr);
/* read the 512 bytes of page data, 2 bytes at a time */
readw(docptr + 0x103c); /* hw quirk */
for (i = 0; i < 256; i++)
*buf++ = readw(docptr + 0x103c);
/* read oob, but discard it */
for (i = 0; i < 7; i++)
readw(docptr + 0x103c);
readw(docptr + DOCG4_OOB_6_7);
readw(docptr + DOCG4_OOB_6_7);
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
writew(0, docptr + DOC_DATAEND);
write_nop(docptr);
write_nop(docptr);
if (!(g4_index & 0x100)) {
/* not redundant subpage read; check for ecc error */
write_nop(docptr);
flash_status = readw(docptr + DOC_ECCCONF1);
flash_status = readw(docptr + DOC_ECCCONF1);
if (flash_status & 0x80) { /* ecc error */
g4_index += 0x108; /* read redundant subpage */
buf -= 256; /* back up ram ptr */
continue;
} else /* no ecc error */
g4_index += 0x210; /* skip redundant subpage */
} else /* redundant page was just read; skip ecc error check */
g4_index += 0x108;
if (g4_index == 0x420) { /* finished with 2k page */
g4_index = 0;
g4_page += 2; /* odd-numbered 2k pages skipped */
}
} while (g4_page != last_g4_page); /* while still on same block */
return 0;
}