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  * $Id: gen_probe.c,v 1.22 2005/01/24 23:49:50 rmk Exp $
   6  */
   7
   8 #include <linux/kernel.h>
   9 #include <linux/slab.h>
  10 #include <linux/module.h>
  11 #include <linux/mtd/mtd.h>
  12 #include <linux/mtd/map.h>
  13 #include <linux/mtd/cfi.h>
  14 #include <linux/mtd/gen_probe.h>
  15
  16 static struct mtd_info *check_cmd_set(struct map_info *, int);
  17 static struct cfi_private *genprobe_ident_chips(struct map_info *map,
  18                                                 struct chip_probe *cp);
  19 static int genprobe_new_chip(struct map_info *map, struct chip_probe *cp,
  20                              struct cfi_private *cfi);
  21
  22 struct mtd_info *mtd_do_chip_probe(struct map_info *map, struct chip_probe *cp)
  23 {
  24         struct mtd_info *mtd = NULL;
  25         struct cfi_private *cfi;
  26
  27         /* First probe the map to see if we have CFI stuff there. */
  28         cfi = genprobe_ident_chips(map, cp);
  29
  30         if (!cfi)
  31                 return NULL;
  32
  33         map->fldrv_priv = cfi;
  34         /* OK we liked it. Now find a driver for the command set it talks */
  35
  36         mtd = check_cmd_set(map, 1); /* First the primary cmdset */
  37         if (!mtd)
  38                 mtd = check_cmd_set(map, 0); /* Then the secondary */
  39
  40         if (mtd)
  41                 return mtd;
  42
  43         printk(KERN_WARNING"gen_probe: No supported Vendor Command Set found\n");
  44
  45         kfree(cfi->cfiq);
  46         kfree(cfi);
  47         map->fldrv_priv = NULL;
  48         return NULL;
  49 }
  50 EXPORT_SYMBOL(mtd_do_chip_probe);
  51
  52
  53 static struct cfi_private *genprobe_ident_chips(struct map_info *map, struct chip_probe *cp)
  54 {
  55         struct cfi_private cfi;
  56         struct cfi_private *retcfi;
  57         unsigned long *chip_map;
  58         int i, j, mapsize;
  59         int max_chips;
  60
  61         memset(&cfi, 0, sizeof(cfi));
  62
  63         /* Call the probetype-specific code with all permutations of
  64            interleave and device type, etc. */
  65         if (!genprobe_new_chip(map, cp, &cfi)) {
  66                 /* The probe didn't like it */
  67                 printk(KERN_DEBUG "%s: Found no %s device at location zero\n",
  68                        cp->name, map->name);
  69                 return NULL;
  70         }
  71
  72 #if 0 /* Let the CFI probe routine do this sanity check. The Intel and AMD
  73          probe routines won't ever return a broken CFI structure anyway,
  74          because they make them up themselves.
  75       */
  76         if (cfi.cfiq->NumEraseRegions == 0) {
  77                 printk(KERN_WARNING "Number of erase regions is zero\n");
  78                 kfree(cfi.cfiq);
  79                 return NULL;
  80         }
  81 #endif
  82         cfi.chipshift = cfi.cfiq->DevSize;
  83
  84         if (cfi_interleave_is_1(&cfi)) {
  85                 ;
  86         } else if (cfi_interleave_is_2(&cfi)) {
  87                 cfi.chipshift++;
  88         } else if (cfi_interleave_is_4((&cfi))) {
  89                 cfi.chipshift += 2;
  90         } else if (cfi_interleave_is_8(&cfi)) {
  91                 cfi.chipshift += 3;
  92         } else {
  93                 BUG();
  94         }
  95
  96         cfi.numchips = 1;
  97
  98         /*
  99          * Allocate memory for bitmap of valid chips.
 100          * Align bitmap storage size to full byte.
 101          */
 102         max_chips = map->size >> cfi.chipshift;
 103         mapsize = (max_chips / 8) + ((max_chips % 8) ? 1 : 0);
 104         chip_map = kmalloc(mapsize, GFP_KERNEL);
 105         if (!chip_map) {
 106                 printk(KERN_WARNING "%s: kmalloc failed for CFI chip map\n", map->name);
 107                 kfree(cfi.cfiq);
 108                 return NULL;
 109         }
 110         memset (chip_map, 0, mapsize);
 111
 112         set_bit(0, chip_map); /* Mark first chip valid */
 113
 114         /*
 115          * Now probe for other chips, checking sensibly for aliases while
 116          * we're at it. The new_chip probe above should have let the first
 117          * chip in read mode.
 118          */
 119
 120         for (i = 1; i < max_chips; i++) {
 121                 cp->probe_chip(map, i << cfi.chipshift, chip_map, &cfi);
 122         }
 123
 124         /*
 125          * Now allocate the space for the structures we need to return to
 126          * our caller, and copy the appropriate data into them.
 127          */
 128
 129         retcfi = kmalloc(sizeof(struct cfi_private) + cfi.numchips * sizeof(struct flchip), GFP_KERNEL);
 130
 131         if (!retcfi) {
 132                 printk(KERN_WARNING "%s: kmalloc failed for CFI private structure\n", map->name);
 133                 kfree(cfi.cfiq);
 134                 kfree(chip_map);
 135                 return NULL;
 136         }
 137
 138         memcpy(retcfi, &cfi, sizeof(cfi));
 139         memset(&retcfi->chips[0], 0, sizeof(struct flchip) * cfi.numchips);
 140
 141         for (i = 0, j = 0; (j < cfi.numchips) && (i < max_chips); i++) {
 142                 if(test_bit(i, chip_map)) {
 143                         struct flchip *pchip = &retcfi->chips[j++];
 144
 145                         pchip->start = (i << cfi.chipshift);
 146                         pchip->state = FL_READY;
 147                         init_waitqueue_head(&pchip->wq);
 148                         spin_lock_init(&pchip->_spinlock);
 149                         pchip->mutex = &pchip->_spinlock;
 150                 }
 151         }
 152
 153         kfree(chip_map);
 154         return retcfi;
 155 }
 156
 157
 158 static int genprobe_new_chip(struct map_info *map, struct chip_probe *cp,
 159                              struct cfi_private *cfi)
 160 {
 161         int min_chips = (map_bankwidth(map)/4?:1); /* At most 4-bytes wide. */
 162         int max_chips = map_bankwidth(map); /* And minimum 1 */
 163         int nr_chips, type;
 164
 165         for (nr_chips = max_chips; nr_chips >= min_chips; nr_chips >>= 1) {
 166
 167                 if (!cfi_interleave_supported(nr_chips))
 168                     continue;
 169
 170                 cfi->interleave = nr_chips;
 171
 172                 /* Minimum device size. Don't look for one 8-bit device
 173                    in a 16-bit bus, etc. */
 174                 type = map_bankwidth(map) / nr_chips;
 175
 176                 for (; type <= CFI_DEVICETYPE_X32; type<<=1) {
 177                         cfi->device_type = type;
 178
 179                         if (cp->probe_chip(map, 0, NULL, cfi))
 180                                 return 1;
 181                 }
 182         }
 183         return 0;
 184 }
 185
 186 typedef struct mtd_info *cfi_cmdset_fn_t(struct map_info *, int);
 187
 188 extern cfi_cmdset_fn_t cfi_cmdset_0001;
 189 extern cfi_cmdset_fn_t cfi_cmdset_0002;
 190 extern cfi_cmdset_fn_t cfi_cmdset_0020;
 191
 192 static inline struct mtd_info *cfi_cmdset_unknown(struct map_info *map,
 193                                                   int primary)
 194 {
 195         struct cfi_private *cfi = map->fldrv_priv;
 196         __u16 type = primary?cfi->cfiq->P_ID:cfi->cfiq->A_ID;
 197 #if defined(CONFIG_MODULES) && defined(HAVE_INTER_MODULE)
 198         char probename[32];
 199         cfi_cmdset_fn_t *probe_function;
 200
 201         sprintf(probename, "cfi_cmdset_%4.4X", type);
 202
 203         probe_function = inter_module_get_request(probename, probename);
 204
 205         if (probe_function) {
 206                 struct mtd_info *mtd;
 207
 208                 mtd = (*probe_function)(map, primary);
 209                 /* If it was happy, it'll have increased its own use count */
 210                 inter_module_put(probename);
 211                 return mtd;
 212         }
 213 #endif
 214         printk(KERN_NOTICE "Support for command set %04X not present\n",
 215                type);
 216
 217         return NULL;
 218 }
 219
 220 static struct mtd_info *check_cmd_set(struct map_info *map, int primary)
 221 {
 222         struct cfi_private *cfi = map->fldrv_priv;
 223         __u16 type = primary?cfi->cfiq->P_ID:cfi->cfiq->A_ID;
 224
 225         if (type == P_ID_NONE || type == P_ID_RESERVED)
 226                 return NULL;
 227
 228         switch(type){
 229                 /* Urgh. Ifdefs. The version with weak symbols was
 230                  * _much_ nicer. Shame it didn't seem to work on
 231                  * anything but x86, really.
 232                  * But we can't rely in inter_module_get() because
 233                  * that'd mean we depend on link order.
 234                  */
 235 #ifdef CONFIG_MTD_CFI_INTELEXT
 236         case 0x0001:
 237         case 0x0003:
 238                 return cfi_cmdset_0001(map, primary);
 239 #endif
 240 #ifdef CONFIG_MTD_CFI_AMDSTD
 241         case 0x0002:
 242                 return cfi_cmdset_0002(map, primary);
 243 #endif
 244 #ifdef CONFIG_MTD_CFI_STAA
 245         case 0x0020:
 246                 return cfi_cmdset_0020(map, primary);
 247 #endif
 248         }
 249
 250         return cfi_cmdset_unknown(map, primary);
 251 }
 252
 253 MODULE_LICENSE("GPL");
 254 MODULE_AUTHOR("David Woodhouse <dwmw2@infradead.org>");
 255 MODULE_DESCRIPTION("Helper routines for flash chip probe code");