drivers/mtd/chips/gen_probe.c

   1 /*
   2  * Routines common to all CFI-type probes.
   3  * (C) 2001-2003 Red Hat, Inc.
   4  * GPL'd
   5  */
   6
   7 #include <linux/kernel.h>
   8 #include <linux/slab.h>
   9 #include <linux/module.h>
  10 #include <linux/mtd/mtd.h>
  11 #include <linux/mtd/map.h>
  12 #include <linux/mtd/cfi.h>
  13 #include <linux/mtd/gen_probe.h>
  14
  15 static struct mtd_info *check_cmd_set(struct map_info *, int);
  16 static struct cfi_private *genprobe_ident_chips(struct map_info *map,
  17                                                 struct chip_probe *cp);
  18 static int genprobe_new_chip(struct map_info *map, struct chip_probe *cp,
  19                              struct cfi_private *cfi);
  20
  21 struct mtd_info *mtd_do_chip_probe(struct map_info *map, struct chip_probe *cp)
  22 {
  23         struct mtd_info *mtd = NULL;
  24         struct cfi_private *cfi;
  25
  26         /* First probe the map to see if we have CFI stuff there. */
  27         cfi = genprobe_ident_chips(map, cp);
  28
  29         if (!cfi)
  30                 return NULL;
  31
  32         map->fldrv_priv = cfi;
  33         /* OK we liked it. Now find a driver for the command set it talks */
  34
  35         mtd = check_cmd_set(map, 1); /* First the primary cmdset */
  36         if (!mtd)
  37                 mtd = check_cmd_set(map, 0); /* Then the secondary */
  38
  39         if (mtd) {
  40                 if (mtd->size > map->size) {
  41                         printk(KERN_WARNING "Reducing visibility of %ldKiB chip to %ldKiB\n",
  42                                (unsigned long)mtd->size >> 10,
  43                                (unsigned long)map->size >> 10);
  44                         mtd->size = map->size;
  45                 }
  46                 return mtd;
  47         }
  48
  49         printk(KERN_WARNING"gen_probe: No supported Vendor Command Set found\n");
  50
  51         kfree(cfi->cfiq);
  52         kfree(cfi);
  53         map->fldrv_priv = NULL;
  54         return NULL;
  55 }
  56 EXPORT_SYMBOL(mtd_do_chip_probe);
  57
  58
  59 static struct cfi_private *genprobe_ident_chips(struct map_info *map, struct chip_probe *cp)
  60 {
  61         struct cfi_private cfi;
  62         struct cfi_private *retcfi;
  63         unsigned long *chip_map;
  64         int i, j, mapsize;
  65         int max_chips;
  66
  67         memset(&cfi, 0, sizeof(cfi));
  68
  69         /* Call the probetype-specific code with all permutations of
  70            interleave and device type, etc. */
  71         if (!genprobe_new_chip(map, cp, &cfi)) {
  72                 /* The probe didn't like it */
  73                 pr_debug("%s: Found no %s device at location zero\n",
  74                          cp->name, map->name);
  75                 return NULL;
  76         }
  77
  78 #if 0 /* Let the CFI probe routine do this sanity check. The Intel and AMD
  79          probe routines won't ever return a broken CFI structure anyway,
  80          because they make them up themselves.
  81       */
  82         if (cfi.cfiq->NumEraseRegions == 0) {
  83                 printk(KERN_WARNING "Number of erase regions is zero\n");
  84                 kfree(cfi.cfiq);
  85                 return NULL;
  86         }
  87 #endif
  88         cfi.chipshift = cfi.cfiq->DevSize;
  89
  90         if (cfi_interleave_is_1(&cfi)) {
  91                 ;
  92         } else if (cfi_interleave_is_2(&cfi)) {
  93                 cfi.chipshift++;
  94         } else if (cfi_interleave_is_4((&cfi))) {
  95                 cfi.chipshift += 2;
  96         } else if (cfi_interleave_is_8(&cfi)) {
  97                 cfi.chipshift += 3;
  98         } else {
  99                 BUG();
 100         }
 101
 102         cfi.numchips = 1;
 103
 104         /*
 105          * Allocate memory for bitmap of valid chips.
 106          * Align bitmap storage size to full byte.
 107          */
 108         max_chips = map->size >> cfi.chipshift;
 109         if (!max_chips) {
 110                 printk(KERN_WARNING "NOR chip too large to fit in mapping. Attempting to cope...\n");
 111                 max_chips = 1;
 112         }
 113
 114         mapsize = sizeof(long) * DIV_ROUND_UP(max_chips, BITS_PER_LONG);
 115         chip_map = kzalloc(mapsize, GFP_KERNEL);
 116         if (!chip_map) {
 117                 printk(KERN_WARNING "%s: kmalloc failed for CFI chip map\n", map->name);
 118                 kfree(cfi.cfiq);
 119                 return NULL;
 120         }
 121
 122         set_bit(0, chip_map); /* Mark first chip valid */
 123
 124         /*
 125          * Now probe for other chips, checking sensibly for aliases while
 126          * we're at it. The new_chip probe above should have let the first
 127          * chip in read mode.
 128          */
 129
 130         for (i = 1; i < max_chips; i++) {
 131                 cp->probe_chip(map, i << cfi.chipshift, chip_map, &cfi);
 132         }
 133
 134         /*
 135          * Now allocate the space for the structures we need to return to
 136          * our caller, and copy the appropriate data into them.
 137          */
 138
 139         retcfi = kmalloc(sizeof(struct cfi_private) + cfi.numchips * sizeof(struct flchip), GFP_KERNEL);
 140
 141         if (!retcfi) {
 142                 printk(KERN_WARNING "%s: kmalloc failed for CFI private structure\n", map->name);
 143                 kfree(cfi.cfiq);
 144                 kfree(chip_map);
 145                 return NULL;
 146         }
 147
 148         memcpy(retcfi, &cfi, sizeof(cfi));
 149         memset(&retcfi->chips[0], 0, sizeof(struct flchip) * cfi.numchips);
 150
 151         for (i = 0, j = 0; (j < cfi.numchips) && (i < max_chips); i++) {
 152                 if(test_bit(i, chip_map)) {
 153                         struct flchip *pchip = &retcfi->chips[j++];
 154
 155                         pchip->start = (i << cfi.chipshift);
 156                         pchip->state = FL_READY;
 157                         init_waitqueue_head(&pchip->wq);
 158                         spin_lock_init(&pchip->_spinlock);
 159                         pchip->mutex = &pchip->_spinlock;
 160                 }
 161         }
 162
 163         kfree(chip_map);
 164         return retcfi;
 165 }
 166
 167
 168 static int genprobe_new_chip(struct map_info *map, struct chip_probe *cp,
 169                              struct cfi_private *cfi)
 170 {
 171         int min_chips = (map_bankwidth(map)/4?:1); /* At most 4-bytes wide. */
 172         int max_chips = map_bankwidth(map); /* And minimum 1 */
 173         int nr_chips, type;
 174
 175         for (nr_chips = max_chips; nr_chips >= min_chips; nr_chips >>= 1) {
 176
 177                 if (!cfi_interleave_supported(nr_chips))
 178                     continue;
 179
 180                 cfi->interleave = nr_chips;
 181
 182                 /* Minimum device size. Don't look for one 8-bit device
 183                    in a 16-bit bus, etc. */
 184                 type = map_bankwidth(map) / nr_chips;
 185
 186                 for (; type <= CFI_DEVICETYPE_X32; type<<=1) {
 187                         cfi->device_type = type;
 188
 189                         if (cp->probe_chip(map, 0, NULL, cfi))
 190                                 return 1;
 191                 }
 192         }
 193         return 0;
 194 }
 195
 196 typedef struct mtd_info *cfi_cmdset_fn_t(struct map_info *, int);
 197
 198 extern cfi_cmdset_fn_t cfi_cmdset_0001;
 199 extern cfi_cmdset_fn_t cfi_cmdset_0002;
 200 extern cfi_cmdset_fn_t cfi_cmdset_0020;
 201
 202 static inline struct mtd_info *cfi_cmdset_unknown(struct map_info *map,
 203                                                   int primary)
 204 {
 205         struct cfi_private *cfi = map->fldrv_priv;
 206         __u16 type = primary?cfi->cfiq->P_ID:cfi->cfiq->A_ID;
 207 #ifdef CONFIG_MODULES
 208         char probename[16+sizeof(MODULE_SYMBOL_PREFIX)];
 209         cfi_cmdset_fn_t *probe_function;
 210
 211         sprintf(probename, MODULE_SYMBOL_PREFIX "cfi_cmdset_%4.4X", type);
 212
 213         probe_function = __symbol_get(probename);
 214         if (!probe_function) {
 215                 request_module(probename + sizeof(MODULE_SYMBOL_PREFIX) - 1);
 216                 probe_function = __symbol_get(probename);
 217         }
 218
 219         if (probe_function) {
 220                 struct mtd_info *mtd;
 221
 222                 mtd = (*probe_function)(map, primary);
 223                 /* If it was happy, it'll have increased its own use count */
 224                 symbol_put_addr(probe_function);
 225                 return mtd;
 226         }
 227 #endif
 228         printk(KERN_NOTICE "Support for command set %04X not present\n", type);
 229
 230         return NULL;
 231 }
 232
 233 static struct mtd_info *check_cmd_set(struct map_info *map, int primary)
 234 {
 235         struct cfi_private *cfi = map->fldrv_priv;
 236         __u16 type = primary?cfi->cfiq->P_ID:cfi->cfiq->A_ID;
 237
 238         if (type == P_ID_NONE || type == P_ID_RESERVED)
 239                 return NULL;
 240
 241         switch(type){
 242                 /* We need these for the !CONFIG_MODULES case,
 243                    because symbol_get() doesn't work there */
 244 #ifdef CONFIG_MTD_CFI_INTELEXT
 245         case 0x0001:
 246         case 0x0003:
 247         case 0x0200:
 248                 return cfi_cmdset_0001(map, primary);
 249 #endif
 250 #ifdef CONFIG_MTD_CFI_AMDSTD
 251         case 0x0002:
 252                 return cfi_cmdset_0002(map, primary);
 253 #endif
 254 #ifdef CONFIG_MTD_CFI_STAA
 255         case 0x0020:
 256                 return cfi_cmdset_0020(map, primary);
 257 #endif
 258         default:
 259                 return cfi_cmdset_unknown(map, primary);
 260         }
 261 }
 262
 263 MODULE_LICENSE("GPL");
 264 MODULE_AUTHOR("David Woodhouse <dwmw2@infradead.org>");
 265 MODULE_DESCRIPTION("Helper routines for flash chip probe code");