1 /* ######################################################################
2
3 Tempustech VMAX SBC301 MTD Driver.
4
5 The VMAx 301 is a SBC based on . It
6 comes with three builtin AMD 29F016B flash chips and a socket for SRAM or
7 more flash. Each unit has it's own 8k mapping into a settable region
8 (0xD8000). There are two 8k mappings for each MTD, the first is always set
9 to the lower 8k of the device the second is paged. Writing a 16 bit page
10 value to anywhere in the first 8k will cause the second 8k to page around.
11
12 To boot the device a bios extension must be installed into the first 8k
13 of flash that is smart enough to copy itself down, page in the rest of
14 itself and begin executing.
15
16 ##################################################################### */
17
18 #include <linux/module.h>
19 #include <linux/slab.h>
20 #include <linux/ioport.h>
21 #include <linux/init.h>
22 #include <linux/spinlock.h>
23 #include <asm/io.h>
24
25 #include <linux/mtd/map.h>
26 #include <linux/mtd/mtd.h>
27
28
29 #define WINDOW_START 0xd8000
30 #define WINDOW_LENGTH 0x2000
31 #define WINDOW_SHIFT 25
32 #define WINDOW_MASK 0x1FFF
33
34 /* Actually we could use two spinlocks, but we'd have to have
35 more private space in the struct map_info. We lose a little
36 performance like this, but we'd probably lose more by having
37 the extra indirection from having one of the map->map_priv
38 fields pointing to yet another private struct.
39 */
40 static DEFINE_SPINLOCK(vmax301_spin);
41
__vmax301_page(struct map_info * map,unsigned long page)42 static void __vmax301_page(struct map_info *map, unsigned long page)
43 {
44 writew(page, map->map_priv_2 - WINDOW_LENGTH);
45 map->map_priv_1 = page;
46 }
47
vmax301_page(struct map_info * map,unsigned long ofs)48 static inline void vmax301_page(struct map_info *map,
49 unsigned long ofs)
50 {
51 unsigned long page = (ofs >> WINDOW_SHIFT);
52 if (map->map_priv_1 != page)
53 __vmax301_page(map, page);
54 }
55
vmax301_read8(struct map_info * map,unsigned long ofs)56 static map_word vmax301_read8(struct map_info *map, unsigned long ofs)
57 {
58 map_word ret;
59 spin_lock(&vmax301_spin);
60 vmax301_page(map, ofs);
61 ret.x[0] = readb(map->map_priv_2 + (ofs & WINDOW_MASK));
62 spin_unlock(&vmax301_spin);
63 return ret;
64 }
65
vmax301_copy_from(struct map_info * map,void * to,unsigned long from,ssize_t len)66 static void vmax301_copy_from(struct map_info *map, void *to, unsigned long from, ssize_t len)
67 {
68 while(len) {
69 unsigned long thislen = len;
70 if (len > (WINDOW_LENGTH - (from & WINDOW_MASK)))
71 thislen = WINDOW_LENGTH-(from & WINDOW_MASK);
72 spin_lock(&vmax301_spin);
73 vmax301_page(map, from);
74 memcpy_fromio(to, map->map_priv_2 + from, thislen);
75 spin_unlock(&vmax301_spin);
76 to += thislen;
77 from += thislen;
78 len -= thislen;
79 }
80 }
81
vmax301_write8(struct map_info * map,map_word d,unsigned long adr)82 static void vmax301_write8(struct map_info *map, map_word d, unsigned long adr)
83 {
84 spin_lock(&vmax301_spin);
85 vmax301_page(map, adr);
86 writeb(d.x[0], map->map_priv_2 + (adr & WINDOW_MASK));
87 spin_unlock(&vmax301_spin);
88 }
89
vmax301_copy_to(struct map_info * map,unsigned long to,const void * from,ssize_t len)90 static void vmax301_copy_to(struct map_info *map, unsigned long to, const void *from, ssize_t len)
91 {
92 while(len) {
93 unsigned long thislen = len;
94 if (len > (WINDOW_LENGTH - (to & WINDOW_MASK)))
95 thislen = WINDOW_LENGTH-(to & WINDOW_MASK);
96
97 spin_lock(&vmax301_spin);
98 vmax301_page(map, to);
99 memcpy_toio(map->map_priv_2 + to, from, thislen);
100 spin_unlock(&vmax301_spin);
101 to += thislen;
102 from += thislen;
103 len -= thislen;
104 }
105 }
106
107 static struct map_info vmax_map[2] = {
108 {
109 .name = "VMAX301 Internal Flash",
110 .phys = NO_XIP,
111 .size = 3*2*1024*1024,
112 .bankwidth = 1,
113 .read = vmax301_read8,
114 .copy_from = vmax301_copy_from,
115 .write = vmax301_write8,
116 .copy_to = vmax301_copy_to,
117 .map_priv_1 = WINDOW_START + WINDOW_LENGTH,
118 .map_priv_2 = 0xFFFFFFFF
119 },
120 {
121 .name = "VMAX301 Socket",
122 .phys = NO_XIP,
123 .size = 0,
124 .bankwidth = 1,
125 .read = vmax301_read8,
126 .copy_from = vmax301_copy_from,
127 .write = vmax301_write8,
128 .copy_to = vmax301_copy_to,
129 .map_priv_1 = WINDOW_START + (3*WINDOW_LENGTH),
130 .map_priv_2 = 0xFFFFFFFF
131 }
132 };
133
134 static struct mtd_info *vmax_mtd[2] = {NULL, NULL};
135
cleanup_vmax301(void)136 static void __exit cleanup_vmax301(void)
137 {
138 int i;
139
140 for (i=0; i<2; i++) {
141 if (vmax_mtd[i]) {
142 del_mtd_device(vmax_mtd[i]);
143 map_destroy(vmax_mtd[i]);
144 }
145 }
146 iounmap((void *)vmax_map[0].map_priv_1 - WINDOW_START);
147 }
148
init_vmax301(void)149 static int __init init_vmax301(void)
150 {
151 int i;
152 unsigned long iomapadr;
153 // Print out our little header..
154 printk("Tempustech VMAX 301 MEM:0x%x-0x%x\n",WINDOW_START,
155 WINDOW_START+4*WINDOW_LENGTH);
156
157 iomapadr = (unsigned long)ioremap(WINDOW_START, WINDOW_LENGTH*4);
158 if (!iomapadr) {
159 printk("Failed to ioremap memory region\n");
160 return -EIO;
161 }
162 /* Put the address in the map's private data area.
163 We store the actual MTD IO address rather than the
164 address of the first half, because it's used more
165 often.
166 */
167 vmax_map[0].map_priv_2 = iomapadr + WINDOW_START;
168 vmax_map[1].map_priv_2 = iomapadr + (3*WINDOW_START);
169
170 for (i=0; i<2; i++) {
171 vmax_mtd[i] = do_map_probe("cfi_probe", &vmax_map[i]);
172 if (!vmax_mtd[i])
173 vmax_mtd[i] = do_map_probe("jedec", &vmax_map[i]);
174 if (!vmax_mtd[i])
175 vmax_mtd[i] = do_map_probe("map_ram", &vmax_map[i]);
176 if (!vmax_mtd[i])
177 vmax_mtd[i] = do_map_probe("map_rom", &vmax_map[i]);
178 if (vmax_mtd[i]) {
179 vmax_mtd[i]->owner = THIS_MODULE;
180 add_mtd_device(vmax_mtd[i]);
181 }
182 }
183
184 if (!vmax_mtd[0] && !vmax_mtd[1]) {
185 iounmap((void *)iomapadr);
186 return -ENXIO;
187 }
188
189 return 0;
190 }
191
192 module_init(init_vmax301);
193 module_exit(cleanup_vmax301);
194
195 MODULE_LICENSE("GPL");
196 MODULE_AUTHOR("David Woodhouse <dwmw2@infradead.org>");
197 MODULE_DESCRIPTION("MTD map driver for Tempustech VMAX SBC301 board");
198