drivers/mtd/maps/amd76xrom.c

   1 /*
   2  * amd76xrom.c
   3  *
   4  * Normal mappings of chips in physical memory
   5  */
   6
   7 #include <linux/module.h>
   8 #include <linux/types.h>
   9 #include <linux/kernel.h>
  10 #include <linux/init.h>
  11 #include <linux/slab.h>
  12 #include <asm/io.h>
  13 #include <linux/mtd/mtd.h>
  14 #include <linux/mtd/map.h>
  15 #include <linux/mtd/cfi.h>
  16 #include <linux/mtd/flashchip.h>
  17 #include <linux/pci.h>
  18 #include <linux/pci_ids.h>
  19 #include <linux/list.h>
  20
  21
  22 #define xstr(s) str(s)
  23 #define str(s) #s
  24 #define MOD_NAME xstr(KBUILD_BASENAME)
  25
  26 #define ADDRESS_NAME_LEN 18
  27
  28 #define ROM_PROBE_STEP_SIZE (64*1024) /* 64KiB */
  29
  30 struct amd76xrom_window {
  31         void __iomem *virt;
  32         unsigned long phys;
  33         unsigned long size;
  34         struct list_head maps;
  35         struct resource rsrc;
  36         struct pci_dev *pdev;
  37 };
  38
  39 struct amd76xrom_map_info {
  40         struct list_head list;
  41         struct map_info map;
  42         struct mtd_info *mtd;
  43         struct resource rsrc;
  44         char map_name[sizeof(MOD_NAME) + 2 + ADDRESS_NAME_LEN];
  45 };
  46
  47 /* The 2 bits controlling the window size are often set to allow reading
  48  * the BIOS, but too small to allow writing, since the lock registers are
  49  * 4MiB lower in the address space than the data.
  50  *
  51  * This is intended to prevent flashing the bios, perhaps accidentally.
  52  *
  53  * This parameter allows the normal driver to over-ride the BIOS settings.
  54  *
  55  * The bits are 6 and 7.  If both bits are set, it is a 5MiB window.
  56  * If only the 7 Bit is set, it is a 4MiB window.  Otherwise, a
  57  * 64KiB window.
  58  *
  59  */
  60 static uint win_size_bits;
  61 module_param(win_size_bits, uint, 0);
  62 MODULE_PARM_DESC(win_size_bits, "ROM window size bits override for 0x43 byte, normally set by BIOS.");
  63
  64 static struct amd76xrom_window amd76xrom_window = {
  65         .maps = LIST_HEAD_INIT(amd76xrom_window.maps),
  66 };
  67
  68 static void amd76xrom_cleanup(struct amd76xrom_window *window)
  69 {
  70         struct amd76xrom_map_info *map, *scratch;
  71         u8 byte;
  72
  73         if (window->pdev) {
  74                 /* Disable writes through the rom window */
  75                 pci_read_config_byte(window->pdev, 0x40, &byte);
  76                 pci_write_config_byte(window->pdev, 0x40, byte & ~1);
  77                 pci_dev_put(window->pdev);
  78         }
  79
  80         /* Free all of the mtd devices */
  81         list_for_each_entry_safe(map, scratch, &window->maps, list) {
  82                 if (map->rsrc.parent) {
  83                         release_resource(&map->rsrc);
  84                 }
  85                 mtd_device_unregister(map->mtd);
  86                 map_destroy(map->mtd);
  87                 list_del(&map->list);
  88                 kfree(map);
  89         }
  90         if (window->rsrc.parent)
  91                 release_resource(&window->rsrc);
  92
  93         if (window->virt) {
  94                 iounmap(window->virt);
  95                 window->virt = NULL;
  96                 window->phys = 0;
  97                 window->size = 0;
  98                 window->pdev = NULL;
  99         }
 100 }
 101
 102
 103 static int amd76xrom_init_one(struct pci_dev *pdev,
 104                               const struct pci_device_id *ent)
 105 {
 106         static char *rom_probe_types[] = { "cfi_probe", "jedec_probe", NULL };
 107         u8 byte;
 108         struct amd76xrom_window *window = &amd76xrom_window;
 109         struct amd76xrom_map_info *map = NULL;
 110         unsigned long map_top;
 111
 112         /* Remember the pci dev I find the window in - already have a ref */
 113         window->pdev = pdev;
 114
 115         /* Enable the selected rom window.  This is often incorrectly
 116          * set up by the BIOS, and the 4MiB offset for the lock registers
 117          * requires the full 5MiB of window space.
 118          *
 119          * This 'write, then read' approach leaves the bits for
 120          * other uses of the hardware info.
 121          */
 122         pci_read_config_byte(pdev, 0x43, &byte);
 123         pci_write_config_byte(pdev, 0x43, byte | win_size_bits );
 124
 125         /* Assume the rom window is properly setup, and find it's size */
 126         pci_read_config_byte(pdev, 0x43, &byte);
 127         if ((byte & ((1<<7)|(1<<6))) == ((1<<7)|(1<<6))) {
 128                 window->phys = 0xffb00000; /* 5MiB */
 129         }
 130         else if ((byte & (1<<7)) == (1<<7)) {
 131                 window->phys = 0xffc00000; /* 4MiB */
 132         }
 133         else {
 134                 window->phys = 0xffff0000; /* 64KiB */
 135         }
 136         window->size = 0xffffffffUL - window->phys + 1UL;
 137
 138         /*
 139          * Try to reserve the window mem region.  If this fails then
 140          * it is likely due to a fragment of the window being
 141          * "reseved" by the BIOS.  In the case that the
 142          * request_mem_region() fails then once the rom size is
 143          * discovered we will try to reserve the unreserved fragment.
 144          */
 145         window->rsrc.name = MOD_NAME;
 146         window->rsrc.start = window->phys;
 147         window->rsrc.end   = window->phys + window->size - 1;
 148         window->rsrc.flags = IORESOURCE_MEM | IORESOURCE_BUSY;
 149         if (request_resource(&iomem_resource, &window->rsrc)) {
 150                 window->rsrc.parent = NULL;
 151                 printk(KERN_ERR MOD_NAME
 152                        " %s(): Unable to register resource %pR - kernel bug?\n",
 153                        __func__, &window->rsrc);
 154                 return -EBUSY;
 155         }
 156
 157
 158         /* Enable writes through the rom window */
 159         pci_read_config_byte(pdev, 0x40, &byte);
 160         pci_write_config_byte(pdev, 0x40, byte | 1);
 161
 162         /* FIXME handle registers 0x80 - 0x8C the bios region locks */
 163
 164         /* For write accesses caches are useless */
 165         window->virt = ioremap_nocache(window->phys, window->size);
 166         if (!window->virt) {
 167                 printk(KERN_ERR MOD_NAME ": ioremap(%08lx, %08lx) failed\n",
 168                         window->phys, window->size);
 169                 goto out;
 170         }
 171
 172         /* Get the first address to look for an rom chip at */
 173         map_top = window->phys;
 174 #if 1
 175         /* The probe sequence run over the firmware hub lock
 176          * registers sets them to 0x7 (no access).
 177          * Probe at most the last 4M of the address space.
 178          */
 179         if (map_top < 0xffc00000) {
 180                 map_top = 0xffc00000;
 181         }
 182 #endif
 183         /* Loop  through and look for rom chips */
 184         while((map_top - 1) < 0xffffffffUL) {
 185                 struct cfi_private *cfi;
 186                 unsigned long offset;
 187                 int i;
 188
 189                 if (!map) {
 190                         map = kmalloc(sizeof(*map), GFP_KERNEL);
 191                 }
 192                 if (!map) {
 193                         printk(KERN_ERR MOD_NAME ": kmalloc failed");
 194                         goto out;
 195                 }
 196                 memset(map, 0, sizeof(*map));
 197                 INIT_LIST_HEAD(&map->list);
 198                 map->map.name = map->map_name;
 199                 map->map.phys = map_top;
 200                 offset = map_top - window->phys;
 201                 map->map.virt = (void __iomem *)
 202                         (((unsigned long)(window->virt)) + offset);
 203                 map->map.size = 0xffffffffUL - map_top + 1UL;
 204                 /* Set the name of the map to the address I am trying */
 205                 sprintf(map->map_name, "%s @%08Lx",
 206                         MOD_NAME, (unsigned long long)map->map.phys);
 207
 208                 /* There is no generic VPP support */
 209                 for(map->map.bankwidth = 32; map->map.bankwidth;
 210                         map->map.bankwidth >>= 1)
 211                 {
 212                         char **probe_type;
 213                         /* Skip bankwidths that are not supported */
 214                         if (!map_bankwidth_supported(map->map.bankwidth))
 215                                 continue;
 216
 217                         /* Setup the map methods */
 218                         simple_map_init(&map->map);
 219
 220                         /* Try all of the probe methods */
 221                         probe_type = rom_probe_types;
 222                         for(; *probe_type; probe_type++) {
 223                                 map->mtd = do_map_probe(*probe_type, &map->map);
 224                                 if (map->mtd)
 225                                         goto found;
 226                         }
 227                 }
 228                 map_top += ROM_PROBE_STEP_SIZE;
 229                 continue;
 230         found:
 231                 /* Trim the size if we are larger than the map */
 232                 if (map->mtd->size > map->map.size) {
 233                         printk(KERN_WARNING MOD_NAME
 234                                 " rom(%llu) larger than window(%lu). fixing...\n",
 235                                 (unsigned long long)map->mtd->size, map->map.size);
 236                         map->mtd->size = map->map.size;
 237                 }
 238                 if (window->rsrc.parent) {
 239                         /*
 240                          * Registering the MTD device in iomem may not be possible
 241                          * if there is a BIOS "reserved" and BUSY range.  If this
 242                          * fails then continue anyway.
 243                          */
 244                         map->rsrc.name  = map->map_name;
 245                         map->rsrc.start = map->map.phys;
 246                         map->rsrc.end   = map->map.phys + map->mtd->size - 1;
 247                         map->rsrc.flags = IORESOURCE_MEM | IORESOURCE_BUSY;
 248                         if (request_resource(&window->rsrc, &map->rsrc)) {
 249                                 printk(KERN_ERR MOD_NAME
 250                                         ": cannot reserve MTD resource\n");
 251                                 map->rsrc.parent = NULL;
 252                         }
 253                 }
 254
 255                 /* Make the whole region visible in the map */
 256                 map->map.virt = window->virt;
 257                 map->map.phys = window->phys;
 258                 cfi = map->map.fldrv_priv;
 259                 for(i = 0; i < cfi->numchips; i++) {
 260                         cfi->chips[i].start += offset;
 261                 }
 262
 263                 /* Now that the mtd devices is complete claim and export it */
 264                 map->mtd->owner = THIS_MODULE;
 265                 if (mtd_device_register(map->mtd, NULL, 0)) {
 266                         map_destroy(map->mtd);
 267                         map->mtd = NULL;
 268                         goto out;
 269                 }
 270
 271
 272                 /* Calculate the new value of map_top */
 273                 map_top += map->mtd->size;
 274
 275                 /* File away the map structure */
 276                 list_add(&map->list, &window->maps);
 277                 map = NULL;
 278         }
 279
 280  out:
 281         /* Free any left over map structures */
 282         kfree(map);
 283         /* See if I have any map structures */
 284         if (list_empty(&window->maps)) {
 285                 amd76xrom_cleanup(window);
 286                 return -ENODEV;
 287         }
 288         return 0;
 289 }
 290
 291
 292 static void amd76xrom_remove_one(struct pci_dev *pdev)
 293 {
 294         struct amd76xrom_window *window = &amd76xrom_window;
 295
 296         amd76xrom_cleanup(window);
 297 }
 298
 299 static struct pci_device_id amd76xrom_pci_tbl[] = {
 300         { PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_VIPER_7410,
 301                 PCI_ANY_ID, PCI_ANY_ID, },
 302         { PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_VIPER_7440,
 303                 PCI_ANY_ID, PCI_ANY_ID, },
 304         { PCI_VENDOR_ID_AMD, 0x7468 }, /* amd8111 support */
 305         { 0, }
 306 };
 307
 308 MODULE_DEVICE_TABLE(pci, amd76xrom_pci_tbl);
 309
 310 #if 0
 311 static struct pci_driver amd76xrom_driver = {
 312         .name =         MOD_NAME,
 313         .id_table =     amd76xrom_pci_tbl,
 314         .probe =        amd76xrom_init_one,
 315         .remove =       amd76xrom_remove_one,
 316 };
 317 #endif
 318
 319 static int __init init_amd76xrom(void)
 320 {
 321         struct pci_dev *pdev;
 322         struct pci_device_id *id;
 323         pdev = NULL;
 324         for(id = amd76xrom_pci_tbl; id->vendor; id++) {
 325                 pdev = pci_get_device(id->vendor, id->device, NULL);
 326                 if (pdev) {
 327                         break;
 328                 }
 329         }
 330         if (pdev) {
 331                 return amd76xrom_init_one(pdev, &amd76xrom_pci_tbl[0]);
 332         }
 333         return -ENXIO;
 334 #if 0
 335         return pci_register_driver(&amd76xrom_driver);
 336 #endif
 337 }
 338
 339 static void __exit cleanup_amd76xrom(void)
 340 {
 341         amd76xrom_remove_one(amd76xrom_window.pdev);
 342 }
 343
 344 module_init(init_amd76xrom);
 345 module_exit(cleanup_amd76xrom);
 346
 347 MODULE_LICENSE("GPL");
 348 MODULE_AUTHOR("Eric Biederman <ebiederman@lnxi.com>");
 349 MODULE_DESCRIPTION("MTD map driver for BIOS chips on the AMD76X southbridge");