aboutsummaryrefslogtreecommitdiff
path: root/drivers/mtd/maps/vmax301.c
blob: 5e68de73eabc9b94fce43255806994f5a8f9baaa (plain)
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
/* ######################################################################

   Tempustech VMAX SBC301 MTD Driver.

   The VMAx 301 is a SBC based on . It
   comes with three builtin AMD 29F016B flash chips and a socket for SRAM or
   more flash. Each unit has it's own 8k mapping into a settable region
   (0xD8000). There are two 8k mappings for each MTD, the first is always set
   to the lower 8k of the device the second is paged. Writing a 16 bit page
   value to anywhere in the first 8k will cause the second 8k to page around.

   To boot the device a bios extension must be installed into the first 8k
   of flash that is smart enough to copy itself down, page in the rest of
   itself and begin executing.

   ##################################################################### */

#include <linux/module.h>
#include <linux/ioport.h>
#include <linux/init.h>
#include <linux/spinlock.h>
#include <asm/io.h>

#include <linux/mtd/map.h>
#include <linux/mtd/mtd.h>


#define WINDOW_START 0xd8000
#define WINDOW_LENGTH 0x2000
#define WINDOW_SHIFT 25
#define WINDOW_MASK 0x1FFF

/* Actually we could use two spinlocks, but we'd have to have
   more private space in the struct map_info. We lose a little
   performance like this, but we'd probably lose more by having
   the extra indirection from having one of the map->map_priv
   fields pointing to yet another private struct.
*/
static DEFINE_SPINLOCK(vmax301_spin);

static void __vmax301_page(struct map_info *map, unsigned long page)
{
	writew(page, map->map_priv_2 - WINDOW_LENGTH);
	map->map_priv_1 = page;
}

static inline void vmax301_page(struct map_info *map,
				  unsigned long ofs)
{
	unsigned long page = (ofs >> WINDOW_SHIFT);
	if (map->map_priv_1 != page)
		__vmax301_page(map, page);
}

static map_word vmax301_read8(struct map_info *map, unsigned long ofs)
{
	map_word ret;
	spin_lock(&vmax301_spin);
	vmax301_page(map, ofs);
	ret.x[0] = readb(map->map_priv_2 + (ofs & WINDOW_MASK));
	spin_unlock(&vmax301_spin);
	return ret;
}

static void vmax301_copy_from(struct map_info *map, void *to, unsigned long from, ssize_t len)
{
	while(len) {
		unsigned long thislen = len;
		if (len > (WINDOW_LENGTH - (from & WINDOW_MASK)))
			thislen = WINDOW_LENGTH-(from & WINDOW_MASK);
		spin_lock(&vmax301_spin);
		vmax301_page(map, from);
		memcpy_fromio(to, map->map_priv_2 + from, thislen);
		spin_unlock(&vmax301_spin);
		to += thislen;
		from += thislen;
		len -= thislen;
	}
}

static void vmax301_write8(struct map_info *map, map_word d, unsigned long adr)
{
	spin_lock(&vmax301_spin);
	vmax301_page(map, adr);
	writeb(d.x[0], map->map_priv_2 + (adr & WINDOW_MASK));
	spin_unlock(&vmax301_spin);
}

static void vmax301_copy_to(struct map_info *map, unsigned long to, const void *from, ssize_t len)
{
	while(len) {
		unsigned long thislen = len;
		if (len > (WINDOW_LENGTH - (to & WINDOW_MASK)))
			thislen = WINDOW_LENGTH-(to & WINDOW_MASK);

		spin_lock(&vmax301_spin);
		vmax301_page(map, to);
		memcpy_toio(map->map_priv_2 + to, from, thislen);
		spin_unlock(&vmax301_spin);
		to += thislen;
		from += thislen;
		len -= thislen;
	}
}

static struct map_info vmax_map[2] = {
	{
		.name = "VMAX301 Internal Flash",
		.phys = NO_XIP,
		.size = 3*2*1024*1024,
		.bankwidth = 1,
		.read = vmax301_read8,
		.copy_from = vmax301_copy_from,
		.write = vmax301_write8,
		.copy_to = vmax301_copy_to,
		.map_priv_1 = WINDOW_START + WINDOW_LENGTH,
		.map_priv_2 = 0xFFFFFFFF
	},
	{
		.name = "VMAX301 Socket",
		.phys = NO_XIP,
		.size = 0,
		.bankwidth = 1,
		.read = vmax301_read8,
		.copy_from = vmax301_copy_from,
		.write = vmax301_write8,
		.copy_to = vmax301_copy_to,
		.map_priv_1 = WINDOW_START + (3*WINDOW_LENGTH),
		.map_priv_2 = 0xFFFFFFFF
	}
};

static struct mtd_info *vmax_mtd[2] = {NULL, NULL};

static void __exit cleanup_vmax301(void)
{
	int i;

	for (i=0; i<2; i++) {
		if (vmax_mtd[i]) {
			mtd_device_unregister(vmax_mtd[i]);
			map_destroy(vmax_mtd[i]);
		}
	}
	iounmap((void *)vmax_map[0].map_priv_1 - WINDOW_START);
}

static int __init init_vmax301(void)
{
	int i;
	unsigned long iomapadr;
	// Print out our little header..
	printk("Tempustech VMAX 301 MEM:0x%x-0x%x\n",WINDOW_START,
	       WINDOW_START+4*WINDOW_LENGTH);

	iomapadr = (unsigned long)ioremap(WINDOW_START, WINDOW_LENGTH*4);
	if (!iomapadr) {
		printk("Failed to ioremap memory region\n");
		return -EIO;
	}
	/* Put the address in the map's private data area.
	   We store the actual MTD IO address rather than the
	   address of the first half, because it's used more
	   often.
	*/
	vmax_map[0].map_priv_2 = iomapadr + WINDOW_START;
	vmax_map[1].map_priv_2 = iomapadr + (3*WINDOW_START);

	for (i=0; i<2; i++) {
		vmax_mtd[i] = do_map_probe("cfi_probe", &vmax_map[i]);
		if (!vmax_mtd[i])
			vmax_mtd[i] = do_map_probe("jedec", &vmax_map[i]);
		if (!vmax_mtd[i])
			vmax_mtd[i] = do_map_probe("map_ram", &vmax_map[i]);
		if (!vmax_mtd[i])
			vmax_mtd[i] = do_map_probe("map_rom", &vmax_map[i]);
		if (vmax_mtd[i]) {
			vmax_mtd[i]->owner = THIS_MODULE;
			mtd_device_register(vmax_mtd[i], NULL, 0);
		}
	}

	if (!vmax_mtd[0] && !vmax_mtd[1]) {
		iounmap((void *)iomapadr);
		return -ENXIO;
	}

	return 0;
}

module_init(init_vmax301);
module_exit(cleanup_vmax301);

MODULE_LICENSE("GPL");
MODULE_AUTHOR("David Woodhouse <dwmw2@infradead.org>");
MODULE_DESCRIPTION("MTD map driver for Tempustech VMAX SBC301 board");