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/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 */
  39 static DEFINE_SPINLOCK(vmax301_spin);
  40
  41 static 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
  47 static 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
  55 static 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
  65 static 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
  81 static 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
  89 static 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
 106 static 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
 133 static struct mtd_info *vmax_mtd[2] = {NULL, NULL};
 134
 135 static void __exit cleanup_vmax301(void)
 136 {
 137         int i;
 138
 139         for (i=0; i<2; i++) {
 140                 if (vmax_mtd[i]) {
 141                         del_mtd_device(vmax_mtd[i]);
 142                         map_destroy(vmax_mtd[i]);
 143                 }
 144         }
 145         iounmap((void *)vmax_map[0].map_priv_1 - WINDOW_START);
 146 }
 147
 148 static 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                         add_mtd_device(vmax_mtd[i]);
 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
 191 module_init(init_vmax301);
 192 module_exit(cleanup_vmax301);
 193
 194 MODULE_LICENSE("GPL");
 195 MODULE_AUTHOR("David Woodhouse <dwmw2@infradead.org>");
 196 MODULE_DESCRIPTION("MTD map driver for Tempustech VMAX SBC301 board");