linux/drivers/mtd/maps/vmax301.c
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   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/ioport.h>
  20#include <linux/init.h>
  21#include <linux/spinlock.h>
  22#include <asm/io.h>
  23
  24#include <linux/mtd/map.h>
  25#include <linux/mtd/mtd.h>
  26
  27
  28#define WINDOW_START 0xd8000
  29#define WINDOW_LENGTH 0x2000
  30#define WINDOW_SHIFT 25
  31#define WINDOW_MASK 0x1FFF
  32
  33/* Actually we could use two spinlocks, but we'd have to have
  34   more private space in the struct map_info. We lose a little
  35   performance like this, but we'd probably lose more by having
  36   the extra indirection from having one of the map->map_priv
  37   fields pointing to yet another private struct.
  38*/
  39static DEFINE_SPINLOCK(vmax301_spin);
  40
  41static void __vmax301_page(struct map_info *map, unsigned long page)
  42{
  43        writew(page, map->map_priv_2 - WINDOW_LENGTH);
  44        map->map_priv_1 = page;
  45}
  46
  47static inline void vmax301_page(struct map_info *map,
  48                                  unsigned long ofs)
  49{
  50        unsigned long page = (ofs >> WINDOW_SHIFT);
  51        if (map->map_priv_1 != page)
  52                __vmax301_page(map, page);
  53}
  54
  55static map_word vmax301_read8(struct map_info *map, unsigned long ofs)
  56{
  57        map_word ret;
  58        spin_lock(&vmax301_spin);
  59        vmax301_page(map, ofs);
  60        ret.x[0] = readb(map->map_priv_2 + (ofs & WINDOW_MASK));
  61        spin_unlock(&vmax301_spin);
  62        return ret;
  63}
  64
  65static void vmax301_copy_from(struct map_info *map, void *to, unsigned long from, ssize_t len)
  66{
  67        while(len) {
  68                unsigned long thislen = len;
  69                if (len > (WINDOW_LENGTH - (from & WINDOW_MASK)))
  70                        thislen = WINDOW_LENGTH-(from & WINDOW_MASK);
  71                spin_lock(&vmax301_spin);
  72                vmax301_page(map, from);
  73                memcpy_fromio(to, map->map_priv_2 + from, thislen);
  74                spin_unlock(&vmax301_spin);
  75                to += thislen;
  76                from += thislen;
  77                len -= thislen;
  78        }
  79}
  80
  81static void vmax301_write8(struct map_info *map, map_word d, unsigned long adr)
  82{
  83        spin_lock(&vmax301_spin);
  84        vmax301_page(map, adr);
  85        writeb(d.x[0], map->map_priv_2 + (adr & WINDOW_MASK));
  86        spin_unlock(&vmax301_spin);
  87}
  88
  89static void vmax301_copy_to(struct map_info *map, unsigned long to, const void *from, ssize_t len)
  90{
  91        while(len) {
  92                unsigned long thislen = len;
  93                if (len > (WINDOW_LENGTH - (to & WINDOW_MASK)))
  94                        thislen = WINDOW_LENGTH-(to & WINDOW_MASK);
  95
  96                spin_lock(&vmax301_spin);
  97                vmax301_page(map, to);
  98                memcpy_toio(map->map_priv_2 + to, from, thislen);
  99                spin_unlock(&vmax301_spin);
 100                to += thislen;
 101                from += thislen;
 102                len -= thislen;
 103        }
 104}
 105
 106static struct map_info vmax_map[2] = {
 107        {
 108                .name = "VMAX301 Internal Flash",
 109                .phys = NO_XIP,
 110                .size = 3*2*1024*1024,
 111                .bankwidth = 1,
 112                .read = vmax301_read8,
 113                .copy_from = vmax301_copy_from,
 114                .write = vmax301_write8,
 115                .copy_to = vmax301_copy_to,
 116                .map_priv_1 = WINDOW_START + WINDOW_LENGTH,
 117                .map_priv_2 = 0xFFFFFFFF
 118        },
 119        {
 120                .name = "VMAX301 Socket",
 121                .phys = NO_XIP,
 122                .size = 0,
 123                .bankwidth = 1,
 124                .read = vmax301_read8,
 125                .copy_from = vmax301_copy_from,
 126                .write = vmax301_write8,
 127                .copy_to = vmax301_copy_to,
 128                .map_priv_1 = WINDOW_START + (3*WINDOW_LENGTH),
 129                .map_priv_2 = 0xFFFFFFFF
 130        }
 131};
 132
 133static struct mtd_info *vmax_mtd[2] = {NULL, NULL};
 134
 135static void __exit cleanup_vmax301(void)
 136{
 137        int i;
 138
 139        for (i=0; i<2; i++) {
 140                if (vmax_mtd[i]) {
 141                        mtd_device_unregister(vmax_mtd[i]);
 142                        map_destroy(vmax_mtd[i]);
 143                }
 144        }
 145        iounmap((void *)vmax_map[0].map_priv_1 - WINDOW_START);
 146}
 147
 148static int __init init_vmax301(void)
 149{
 150        int i;
 151        unsigned long iomapadr;
 152        // Print out our little header..
 153        printk("Tempustech VMAX 301 MEM:0x%x-0x%x\n",WINDOW_START,
 154               WINDOW_START+4*WINDOW_LENGTH);
 155
 156        iomapadr = (unsigned long)ioremap(WINDOW_START, WINDOW_LENGTH*4);
 157        if (!iomapadr) {
 158                printk("Failed to ioremap memory region\n");
 159                return -EIO;
 160        }
 161        /* Put the address in the map's private data area.
 162           We store the actual MTD IO address rather than the
 163           address of the first half, because it's used more
 164           often.
 165        */
 166        vmax_map[0].map_priv_2 = iomapadr + WINDOW_START;
 167        vmax_map[1].map_priv_2 = iomapadr + (3*WINDOW_START);
 168
 169        for (i=0; i<2; i++) {
 170                vmax_mtd[i] = do_map_probe("cfi_probe", &vmax_map[i]);
 171                if (!vmax_mtd[i])
 172                        vmax_mtd[i] = do_map_probe("jedec", &vmax_map[i]);
 173                if (!vmax_mtd[i])
 174                        vmax_mtd[i] = do_map_probe("map_ram", &vmax_map[i]);
 175                if (!vmax_mtd[i])
 176                        vmax_mtd[i] = do_map_probe("map_rom", &vmax_map[i]);
 177                if (vmax_mtd[i]) {
 178                        vmax_mtd[i]->owner = THIS_MODULE;
 179                        mtd_device_register(vmax_mtd[i], NULL, 0);
 180                }
 181        }
 182
 183        if (!vmax_mtd[0] && !vmax_mtd[1]) {
 184                iounmap((void *)iomapadr);
 185                return -ENXIO;
 186        }
 187
 188        return 0;
 189}
 190
 191module_init(init_vmax301);
 192module_exit(cleanup_vmax301);
 193
 194MODULE_LICENSE("GPL");
 195MODULE_AUTHOR("David Woodhouse <dwmw2@infradead.org>");
 196MODULE_DESCRIPTION("MTD map driver for Tempustech VMAX SBC301 board");
 197