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 1.24 2005/11/07 11:14:23 gleixner 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                 if (mtd->size > map->size) {
  42                         printk(KERN_WARNING "Reducing visibility of %ldKiB chip to %ldKiB\n",
  43                                (unsigned long)mtd->size >> 10,
  44                                (unsigned long)map->size >> 10);
  45                         mtd->size = map->size;
  46                 }
  47                 return mtd;
  48         }
  49
  50         printk(KERN_WARNING"gen_probe: No supported Vendor Command Set found\n");
  51
  52         kfree(cfi->cfiq);
  53         kfree(cfi);
  54         map->fldrv_priv = NULL;
  55         return NULL;
  56 }
  57 EXPORT_SYMBOL(mtd_do_chip_probe);
  58
  59
  60 static struct cfi_private *genprobe_ident_chips(struct map_info *map, struct chip_probe *cp)
  61 {
  62         struct cfi_private cfi;
  63         struct cfi_private *retcfi;
  64         unsigned long *chip_map;
  65         int i, j, mapsize;
  66         int max_chips;
  67
  68         memset(&cfi, 0, sizeof(cfi));
  69
  70         /* Call the probetype-specific code with all permutations of
  71            interleave and device type, etc. */
  72         if (!genprobe_new_chip(map, cp, &cfi)) {
  73                 /* The probe didn't like it */
  74                 printk(KERN_DEBUG "%s: Found no %s device at location zero\n",
  75                        cp->name, map->name);
  76                 return NULL;
  77         }
  78
  79 #if 0 /* Let the CFI probe routine do this sanity check. The Intel and AMD
  80          probe routines won't ever return a broken CFI structure anyway,
  81          because they make them up themselves.
  82       */
  83         if (cfi.cfiq->NumEraseRegions == 0) {
  84                 printk(KERN_WARNING "Number of erase regions is zero\n");
  85                 kfree(cfi.cfiq);
  86                 return NULL;
  87         }
  88 #endif
  89         cfi.chipshift = cfi.cfiq->DevSize;
  90
  91         if (cfi_interleave_is_1(&cfi)) {
  92                 ;
  93         } else if (cfi_interleave_is_2(&cfi)) {
  94                 cfi.chipshift++;
  95         } else if (cfi_interleave_is_4((&cfi))) {
  96                 cfi.chipshift += 2;
  97         } else if (cfi_interleave_is_8(&cfi)) {
  98                 cfi.chipshift += 3;
  99         } else {
 100                 BUG();
 101         }
 102
 103         cfi.numchips = 1;
 104
 105         /*
 106          * Allocate memory for bitmap of valid chips.
 107          * Align bitmap storage size to full byte.
 108          */
 109         max_chips = map->size >> cfi.chipshift;
 110         if (!max_chips) {
 111                 printk(KERN_WARNING "NOR chip too large to fit in mapping. Attempting to cope...\n");
 112                 max_chips = 1;
 113         }
 114
 115         mapsize = (max_chips + BITS_PER_LONG-1) / BITS_PER_LONG;
 116         chip_map = kzalloc(mapsize, GFP_KERNEL);
 117         if (!chip_map) {
 118                 printk(KERN_WARNING "%s: kmalloc failed for CFI chip map\n", map->name);
 119                 kfree(cfi.cfiq);
 120                 return NULL;
 121         }
 122
 123         set_bit(0, chip_map); /* Mark first chip valid */
 124
 125         /*
 126          * Now probe for other chips, checking sensibly for aliases while
 127          * we're at it. The new_chip probe above should have let the first
 128          * chip in read mode.
 129          */
 130
 131         for (i = 1; i < max_chips; i++) {
 132                 cp->probe_chip(map, i << cfi.chipshift, chip_map, &cfi);
 133         }
 134
 135         /*
 136          * Now allocate the space for the structures we need to return to
 137          * our caller, and copy the appropriate data into them.
 138          */
 139
 140         retcfi = kmalloc(sizeof(struct cfi_private) + cfi.numchips * sizeof(struct flchip), GFP_KERNEL);
 141
 142         if (!retcfi) {
 143                 printk(KERN_WARNING "%s: kmalloc failed for CFI private structure\n", map->name);
 144                 kfree(cfi.cfiq);
 145                 kfree(chip_map);
 146                 return NULL;
 147         }
 148
 149         memcpy(retcfi, &cfi, sizeof(cfi));
 150         memset(&retcfi->chips[0], 0, sizeof(struct flchip) * cfi.numchips);
 151
 152         for (i = 0, j = 0; (j < cfi.numchips) && (i < max_chips); i++) {
 153                 if(test_bit(i, chip_map)) {
 154                         struct flchip *pchip = &retcfi->chips[j++];
 155
 156                         pchip->start = (i << cfi.chipshift);
 157                         pchip->state = FL_READY;
 158                         init_waitqueue_head(&pchip->wq);
 159                         spin_lock_init(&pchip->_spinlock);
 160                         pchip->mutex = &pchip->_spinlock;
 161                 }
 162         }
 163
 164         kfree(chip_map);
 165         return retcfi;
 166 }
 167
 168
 169 static int genprobe_new_chip(struct map_info *map, struct chip_probe *cp,
 170                              struct cfi_private *cfi)
 171 {
 172         int min_chips = (map_bankwidth(map)/4?:1); /* At most 4-bytes wide. */
 173         int max_chips = map_bankwidth(map); /* And minimum 1 */
 174         int nr_chips, type;
 175
 176         for (nr_chips = max_chips; nr_chips >= min_chips; nr_chips >>= 1) {
 177
 178                 if (!cfi_interleave_supported(nr_chips))
 179                     continue;
 180
 181                 cfi->interleave = nr_chips;
 182
 183                 /* Minimum device size. Don't look for one 8-bit device
 184                    in a 16-bit bus, etc. */
 185                 type = map_bankwidth(map) / nr_chips;
 186
 187                 for (; type <= CFI_DEVICETYPE_X32; type<<=1) {
 188                         cfi->device_type = type;
 189
 190                         if (cp->probe_chip(map, 0, NULL, cfi))
 191                                 return 1;
 192                 }
 193         }
 194         return 0;
 195 }
 196
 197 typedef struct mtd_info *cfi_cmdset_fn_t(struct map_info *, int);
 198
 199 extern cfi_cmdset_fn_t cfi_cmdset_0001;
 200 extern cfi_cmdset_fn_t cfi_cmdset_0002;
 201 extern cfi_cmdset_fn_t cfi_cmdset_0020;
 202
 203 static inline struct mtd_info *cfi_cmdset_unknown(struct map_info *map,
 204                                                   int primary)
 205 {
 206         struct cfi_private *cfi = map->fldrv_priv;
 207         __u16 type = primary?cfi->cfiq->P_ID:cfi->cfiq->A_ID;
 208 #ifdef CONFIG_MODULES
 209         char probename[16+sizeof(MODULE_SYMBOL_PREFIX)];
 210         cfi_cmdset_fn_t *probe_function;
 211
 212         sprintf(probename, MODULE_SYMBOL_PREFIX "cfi_cmdset_%4.4X", type);
 213
 214         probe_function = __symbol_get(probename);
 215         if (!probe_function) {
 216                 request_module(probename + sizeof(MODULE_SYMBOL_PREFIX) - 1);
 217                 probe_function = __symbol_get(probename);
 218         }
 219
 220         if (probe_function) {
 221                 struct mtd_info *mtd;
 222
 223                 mtd = (*probe_function)(map, primary);
 224                 /* If it was happy, it'll have increased its own use count */
 225                 symbol_put_addr(probe_function);
 226                 return mtd;
 227         }
 228 #endif
 229         printk(KERN_NOTICE "Support for command set %04X not present\n", type);
 230
 231         return NULL;
 232 }
 233
 234 static struct mtd_info *check_cmd_set(struct map_info *map, int primary)
 235 {
 236         struct cfi_private *cfi = map->fldrv_priv;
 237         __u16 type = primary?cfi->cfiq->P_ID:cfi->cfiq->A_ID;
 238
 239         if (type == P_ID_NONE || type == P_ID_RESERVED)
 240                 return NULL;
 241
 242         switch(type){
 243                 /* We need these for the !CONFIG_MODULES case,
 244                    because symbol_get() doesn't work there */
 245 #ifdef CONFIG_MTD_CFI_INTELEXT
 246         case 0x0001:
 247         case 0x0003:
 248         case 0x0200:
 249                 return cfi_cmdset_0001(map, primary);
 250 #endif
 251 #ifdef CONFIG_MTD_CFI_AMDSTD
 252         case 0x0002:
 253                 return cfi_cmdset_0002(map, primary);
 254 #endif
 255 #ifdef CONFIG_MTD_CFI_STAA
 256         case 0x0020:
 257                 return cfi_cmdset_0020(map, primary);
 258 #endif
 259         default:
 260                 return cfi_cmdset_unknown(map, primary);
 261         }
 262 }
 263
 264 MODULE_LICENSE("GPL");
 265 MODULE_AUTHOR("David Woodhouse <dwmw2@infradead.org>");
 266 MODULE_DESCRIPTION("Helper routines for flash chip probe code");