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/* ######################################################################
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");
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