drivers/mtd/maps/vmax301.c

   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
  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
  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
  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
  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
  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
  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
 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
 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");