vmax301.c revision 1aed165a602b80428bbdf17478c629169d96eda1 
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*/
40static DEFINE_SPINLOCK(vmax301_spin);
41
42static 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
48static 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
56static 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
66static 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
82static 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
90static 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
107static 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
134static struct mtd_info *vmax_mtd[2] = {NULL, NULL};
135
136static 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
149static 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
192module_init(init_vmax301);
193module_exit(cleanup_vmax301);
194
195MODULE_LICENSE("GPL");
196MODULE_AUTHOR("David Woodhouse <dwmw2@infradead.org>");
197MODULE_DESCRIPTION("MTD map driver for Tempustech VMAX SBC301 board");
198