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
156
157
158
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
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
|
/*
* This program is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 as published
* by the Free Software Foundation.
*
* Copyright (C) 2004 Liu Peng Infineon IFAP DC COM CPE
* Copyright (C) 2010 John Crispin <john@phrozen.org>
*/
#include <linux/err.h>
#include <linux/module.h>
#include <linux/types.h>
#include <linux/kernel.h>
#include <linux/io.h>
#include <linux/slab.h>
#include <linux/mtd/mtd.h>
#include <linux/mtd/map.h>
#include <linux/mtd/partitions.h>
#include <linux/mtd/cfi.h>
#include <linux/platform_device.h>
#include <linux/mtd/physmap.h>
#include <linux/of.h>
#include <lantiq_soc.h>
/*
* The NOR flash is connected to the same external bus unit (EBU) as PCI.
* To make PCI work we need to enable the endianness swapping for the address
* written to the EBU. This endianness swapping works for PCI correctly but
* fails for attached NOR devices. To workaround this we need to use a complex
* map. The workaround involves swapping all addresses whilst probing the chip.
* Once probing is complete we stop swapping the addresses but swizzle the
* unlock addresses to ensure that access to the NOR device works correctly.
*/
enum {
LTQ_NOR_PROBING,
LTQ_NOR_NORMAL
};
struct ltq_mtd {
struct resource *res;
struct mtd_info *mtd;
struct map_info *map;
};
static const char ltq_map_name[] = "ltq_nor";
static map_word
ltq_read16(struct map_info *map, unsigned long adr)
{
unsigned long flags;
map_word temp;
if (map->map_priv_1 == LTQ_NOR_PROBING)
adr ^= 2;
spin_lock_irqsave(&ebu_lock, flags);
temp.x[0] = *(u16 *)(map->virt + adr);
spin_unlock_irqrestore(&ebu_lock, flags);
return temp;
}
static void
ltq_write16(struct map_info *map, map_word d, unsigned long adr)
{
unsigned long flags;
if (map->map_priv_1 == LTQ_NOR_PROBING)
adr ^= 2;
spin_lock_irqsave(&ebu_lock, flags);
*(u16 *)(map->virt + adr) = d.x[0];
spin_unlock_irqrestore(&ebu_lock, flags);
}
/*
* The following 2 functions copy data between iomem and a cached memory
* section. As memcpy() makes use of pre-fetching we cannot use it here.
* The normal alternative of using memcpy_{to,from}io also makes use of
* memcpy() on MIPS so it is not applicable either. We are therefore stuck
* with having to use our own loop.
*/
static void
ltq_copy_from(struct map_info *map, void *to,
unsigned long from, ssize_t len)
{
unsigned char *f = (unsigned char *)map->virt + from;
unsigned char *t = (unsigned char *)to;
unsigned long flags;
spin_lock_irqsave(&ebu_lock, flags);
while (len--)
*t++ = *f++;
spin_unlock_irqrestore(&ebu_lock, flags);
}
static void
ltq_copy_to(struct map_info *map, unsigned long to,
const void *from, ssize_t len)
{
unsigned char *f = (unsigned char *)from;
unsigned char *t = (unsigned char *)map->virt + to;
unsigned long flags;
spin_lock_irqsave(&ebu_lock, flags);
while (len--)
*t++ = *f++;
spin_unlock_irqrestore(&ebu_lock, flags);
}
static int
ltq_mtd_probe(struct platform_device *pdev)
{
struct ltq_mtd *ltq_mtd;
struct cfi_private *cfi;
int err;
if (of_machine_is_compatible("lantiq,falcon") &&
(ltq_boot_select() != BS_FLASH)) {
dev_err(&pdev->dev, "invalid bootstrap options\n");
return -ENODEV;
}
ltq_mtd = devm_kzalloc(&pdev->dev, sizeof(struct ltq_mtd), GFP_KERNEL);
if (!ltq_mtd)
return -ENOMEM;
platform_set_drvdata(pdev, ltq_mtd);
ltq_mtd->res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
if (!ltq_mtd->res) {
dev_err(&pdev->dev, "failed to get memory resource\n");
return -ENOENT;
}
ltq_mtd->map = devm_kzalloc(&pdev->dev, sizeof(struct map_info),
GFP_KERNEL);
if (!ltq_mtd->map)
return -ENOMEM;
ltq_mtd->map->phys = ltq_mtd->res->start;
ltq_mtd->map->size = resource_size(ltq_mtd->res);
ltq_mtd->map->virt = devm_ioremap_resource(&pdev->dev, ltq_mtd->res);
if (IS_ERR(ltq_mtd->map->virt))
return PTR_ERR(ltq_mtd->map->virt);
ltq_mtd->map->name = ltq_map_name;
ltq_mtd->map->bankwidth = 2;
ltq_mtd->map->read = ltq_read16;
ltq_mtd->map->write = ltq_write16;
ltq_mtd->map->copy_from = ltq_copy_from;
ltq_mtd->map->copy_to = ltq_copy_to;
ltq_mtd->map->map_priv_1 = LTQ_NOR_PROBING;
ltq_mtd->mtd = do_map_probe("cfi_probe", ltq_mtd->map);
ltq_mtd->map->map_priv_1 = LTQ_NOR_NORMAL;
if (!ltq_mtd->mtd) {
dev_err(&pdev->dev, "probing failed\n");
return -ENXIO;
}
ltq_mtd->mtd->dev.parent = &pdev->dev;
mtd_set_of_node(ltq_mtd->mtd, pdev->dev.of_node);
cfi = ltq_mtd->map->fldrv_priv;
cfi->addr_unlock1 ^= 1;
cfi->addr_unlock2 ^= 1;
err = mtd_device_register(ltq_mtd->mtd, NULL, 0);
if (err) {
dev_err(&pdev->dev, "failed to add partitions\n");
goto err_destroy;
}
return 0;
err_destroy:
map_destroy(ltq_mtd->mtd);
return err;
}
static int
ltq_mtd_remove(struct platform_device *pdev)
{
struct ltq_mtd *ltq_mtd = platform_get_drvdata(pdev);
if (ltq_mtd && ltq_mtd->mtd) {
mtd_device_unregister(ltq_mtd->mtd);
map_destroy(ltq_mtd->mtd);
}
return 0;
}
static const struct of_device_id ltq_mtd_match[] = {
{ .compatible = "lantiq,nor" },
{},
};
MODULE_DEVICE_TABLE(of, ltq_mtd_match);
static struct platform_driver ltq_mtd_driver = {
.probe = ltq_mtd_probe,
.remove = ltq_mtd_remove,
.driver = {
.name = "ltq-nor",
.of_match_table = ltq_mtd_match,
},
};
module_platform_driver(ltq_mtd_driver);
MODULE_LICENSE("GPL");
MODULE_AUTHOR("John Crispin <john@phrozen.org>");
MODULE_DESCRIPTION("Lantiq SoC NOR");
|
