drivers/mtd/devices/docprobe.c

   1
   2 /* Linux driver for Disk-On-Chip devices                        */
   3 /* Probe routines common to all DoC devices                     */
   4 /* (C) 1999 Machine Vision Holdings, Inc.                       */
   5 /* (C) 1999-2003 David Woodhouse <dwmw2@infradead.org>          */
   6
   7
   8 /* DOC_PASSIVE_PROBE:
   9    In order to ensure that the BIOS checksum is correct at boot time, and
  10    hence that the onboard BIOS extension gets executed, the DiskOnChip
  11    goes into reset mode when it is read sequentially: all registers
  12    return 0xff until the chip is woken up again by writing to the
  13    DOCControl register.
  14
  15    Unfortunately, this means that the probe for the DiskOnChip is unsafe,
  16    because one of the first things it does is write to where it thinks
  17    the DOCControl register should be - which may well be shared memory
  18    for another device. I've had machines which lock up when this is
  19    attempted. Hence the possibility to do a passive probe, which will fail
  20    to detect a chip in reset mode, but is at least guaranteed not to lock
  21    the machine.
  22
  23    If you have this problem, uncomment the following line:
  24 #define DOC_PASSIVE_PROBE
  25 */
  26
  27
  28 /* DOC_SINGLE_DRIVER:
  29    Millennium driver has been merged into DOC2000 driver.
  30
  31    The old Millennium-only driver has been retained just in case there
  32    are problems with the new code. If the combined driver doesn't work
  33    for you, you can try the old one by undefining DOC_SINGLE_DRIVER
  34    below and also enabling it in your configuration. If this fixes the
  35    problems, please send a report to the MTD mailing list at
  36    <linux-mtd@lists.infradead.org>.
  37 */
  38 #define DOC_SINGLE_DRIVER
  39
  40 #include <linux/kernel.h>
  41 #include <linux/module.h>
  42 #include <asm/errno.h>
  43 #include <asm/io.h>
  44 #include <linux/delay.h>
  45 #include <linux/slab.h>
  46 #include <linux/init.h>
  47 #include <linux/types.h>
  48
  49 #include <linux/mtd/mtd.h>
  50 #include <linux/mtd/nand.h>
  51 #include <linux/mtd/doc2000.h>
  52
  53
  54 static unsigned long doc_config_location = CONFIG_MTD_DOCPROBE_ADDRESS;
  55 module_param(doc_config_location, ulong, 0);
  56 MODULE_PARM_DESC(doc_config_location, "Physical memory address at which to probe for DiskOnChip");
  57
  58 static unsigned long __initdata doc_locations[] = {
  59 #if defined (__alpha__) || defined(__i386__) || defined(__x86_64__)
  60 #ifdef CONFIG_MTD_DOCPROBE_HIGH
  61         0xfffc8000, 0xfffca000, 0xfffcc000, 0xfffce000,
  62         0xfffd0000, 0xfffd2000, 0xfffd4000, 0xfffd6000,
  63         0xfffd8000, 0xfffda000, 0xfffdc000, 0xfffde000,
  64         0xfffe0000, 0xfffe2000, 0xfffe4000, 0xfffe6000,
  65         0xfffe8000, 0xfffea000, 0xfffec000, 0xfffee000,
  66 #else /*  CONFIG_MTD_DOCPROBE_HIGH */
  67         0xc8000, 0xca000, 0xcc000, 0xce000,
  68         0xd0000, 0xd2000, 0xd4000, 0xd6000,
  69         0xd8000, 0xda000, 0xdc000, 0xde000,
  70         0xe0000, 0xe2000, 0xe4000, 0xe6000,
  71         0xe8000, 0xea000, 0xec000, 0xee000,
  72 #endif /*  CONFIG_MTD_DOCPROBE_HIGH */
  73 #else
  74 #warning Unknown architecture for DiskOnChip. No default probe locations defined
  75 #endif
  76         0xffffffff };
  77
  78 /* doccheck: Probe a given memory window to see if there's a DiskOnChip present */
  79
  80 static inline int __init doccheck(void __iomem *potential, unsigned long physadr)
  81 {
  82         void __iomem *window=potential;
  83         unsigned char tmp, tmpb, tmpc, ChipID;
  84 #ifndef DOC_PASSIVE_PROBE
  85         unsigned char tmp2;
  86 #endif
  87
  88         /* Routine copied from the Linux DOC driver */
  89
  90 #ifdef CONFIG_MTD_DOCPROBE_55AA
  91         /* Check for 0x55 0xAA signature at beginning of window,
  92            this is no longer true once we remove the IPL (for Millennium */
  93         if (ReadDOC(window, Sig1) != 0x55 || ReadDOC(window, Sig2) != 0xaa)
  94                 return 0;
  95 #endif /* CONFIG_MTD_DOCPROBE_55AA */
  96
  97 #ifndef DOC_PASSIVE_PROBE
  98         /* It's not possible to cleanly detect the DiskOnChip - the
  99          * bootup procedure will put the device into reset mode, and
 100          * it's not possible to talk to it without actually writing
 101          * to the DOCControl register. So we store the current contents
 102          * of the DOCControl register's location, in case we later decide
 103          * that it's not a DiskOnChip, and want to put it back how we
 104          * found it.
 105          */
 106         tmp2 = ReadDOC(window, DOCControl);
 107
 108         /* Reset the DiskOnChip ASIC */
 109         WriteDOC(DOC_MODE_CLR_ERR | DOC_MODE_MDWREN | DOC_MODE_RESET,
 110                  window, DOCControl);
 111         WriteDOC(DOC_MODE_CLR_ERR | DOC_MODE_MDWREN | DOC_MODE_RESET,
 112                  window, DOCControl);
 113
 114         /* Enable the DiskOnChip ASIC */
 115         WriteDOC(DOC_MODE_CLR_ERR | DOC_MODE_MDWREN | DOC_MODE_NORMAL,
 116                  window, DOCControl);
 117         WriteDOC(DOC_MODE_CLR_ERR | DOC_MODE_MDWREN | DOC_MODE_NORMAL,
 118                  window, DOCControl);
 119 #endif /* !DOC_PASSIVE_PROBE */
 120
 121         /* We need to read the ChipID register four times. For some
 122            newer DiskOnChip 2000 units, the first three reads will
 123            return the DiskOnChip Millennium ident. Don't ask. */
 124         ChipID = ReadDOC(window, ChipID);
 125
 126         switch (ChipID) {
 127         case DOC_ChipID_Doc2k:
 128                 /* Check the TOGGLE bit in the ECC register */
 129                 tmp  = ReadDOC(window, 2k_ECCStatus) & DOC_TOGGLE_BIT;
 130                 tmpb = ReadDOC(window, 2k_ECCStatus) & DOC_TOGGLE_BIT;
 131                 tmpc = ReadDOC(window, 2k_ECCStatus) & DOC_TOGGLE_BIT;
 132                 if (tmp != tmpb && tmp == tmpc)
 133                                 return ChipID;
 134                 break;
 135
 136         case DOC_ChipID_DocMil:
 137                 /* Check for the new 2000 with Millennium ASIC */
 138                 ReadDOC(window, ChipID);
 139                 ReadDOC(window, ChipID);
 140                 if (ReadDOC(window, ChipID) != DOC_ChipID_DocMil)
 141                         ChipID = DOC_ChipID_Doc2kTSOP;
 142
 143                 /* Check the TOGGLE bit in the ECC register */
 144                 tmp  = ReadDOC(window, ECCConf) & DOC_TOGGLE_BIT;
 145                 tmpb = ReadDOC(window, ECCConf) & DOC_TOGGLE_BIT;
 146                 tmpc = ReadDOC(window, ECCConf) & DOC_TOGGLE_BIT;
 147                 if (tmp != tmpb && tmp == tmpc)
 148                                 return ChipID;
 149                 break;
 150
 151         case DOC_ChipID_DocMilPlus16:
 152         case DOC_ChipID_DocMilPlus32:
 153         case 0:
 154                 /* Possible Millennium+, need to do more checks */
 155 #ifndef DOC_PASSIVE_PROBE
 156                 /* Possibly release from power down mode */
 157                 for (tmp = 0; (tmp < 4); tmp++)
 158                         ReadDOC(window, Mplus_Power);
 159
 160                 /* Reset the DiskOnChip ASIC */
 161                 tmp = DOC_MODE_RESET | DOC_MODE_MDWREN | DOC_MODE_RST_LAT |
 162                         DOC_MODE_BDECT;
 163                 WriteDOC(tmp, window, Mplus_DOCControl);
 164                 WriteDOC(~tmp, window, Mplus_CtrlConfirm);
 165
 166                 mdelay(1);
 167                 /* Enable the DiskOnChip ASIC */
 168                 tmp = DOC_MODE_NORMAL | DOC_MODE_MDWREN | DOC_MODE_RST_LAT |
 169                         DOC_MODE_BDECT;
 170                 WriteDOC(tmp, window, Mplus_DOCControl);
 171                 WriteDOC(~tmp, window, Mplus_CtrlConfirm);
 172                 mdelay(1);
 173 #endif /* !DOC_PASSIVE_PROBE */
 174
 175                 ChipID = ReadDOC(window, ChipID);
 176
 177                 switch (ChipID) {
 178                 case DOC_ChipID_DocMilPlus16:
 179                 case DOC_ChipID_DocMilPlus32:
 180                         /* Check the TOGGLE bit in the toggle register */
 181                         tmp  = ReadDOC(window, Mplus_Toggle) & DOC_TOGGLE_BIT;
 182                         tmpb = ReadDOC(window, Mplus_Toggle) & DOC_TOGGLE_BIT;
 183                         tmpc = ReadDOC(window, Mplus_Toggle) & DOC_TOGGLE_BIT;
 184                         if (tmp != tmpb && tmp == tmpc)
 185                                         return ChipID;
 186                 default:
 187                         break;
 188                 }
 189                 /* FALL TRHU */
 190
 191         default:
 192
 193 #ifdef CONFIG_MTD_DOCPROBE_55AA
 194                 printk(KERN_DEBUG "Possible DiskOnChip with unknown ChipID %2.2X found at 0x%lx\n",
 195                        ChipID, physadr);
 196 #endif
 197 #ifndef DOC_PASSIVE_PROBE
 198                 /* Put back the contents of the DOCControl register, in case it's not
 199                  * actually a DiskOnChip.
 200                  */
 201                 WriteDOC(tmp2, window, DOCControl);
 202 #endif
 203                 return 0;
 204         }
 205
 206         printk(KERN_WARNING "DiskOnChip failed TOGGLE test, dropping.\n");
 207
 208 #ifndef DOC_PASSIVE_PROBE
 209         /* Put back the contents of the DOCControl register: it's not a DiskOnChip */
 210         WriteDOC(tmp2, window, DOCControl);
 211 #endif
 212         return 0;
 213 }
 214
 215 static int docfound;
 216
 217 extern void DoC2k_init(struct mtd_info *);
 218 extern void DoCMil_init(struct mtd_info *);
 219 extern void DoCMilPlus_init(struct mtd_info *);
 220
 221 static void __init DoC_Probe(unsigned long physadr)
 222 {
 223         void __iomem *docptr;
 224         struct DiskOnChip *this;
 225         struct mtd_info *mtd;
 226         int ChipID;
 227         char namebuf[15];
 228         char *name = namebuf;
 229         void (*initroutine)(struct mtd_info *) = NULL;
 230
 231         docptr = ioremap(physadr, DOC_IOREMAP_LEN);
 232
 233         if (!docptr)
 234                 return;
 235
 236         if ((ChipID = doccheck(docptr, physadr))) {
 237                 if (ChipID == DOC_ChipID_Doc2kTSOP) {
 238                         /* Remove this at your own peril. The hardware driver works but nothing prevents you from erasing bad blocks */
 239                         printk(KERN_NOTICE "Refusing to drive DiskOnChip 2000 TSOP until Bad Block Table is correctly supported by INFTL\n");
 240                         iounmap(docptr);
 241                         return;
 242                 }
 243                 docfound = 1;
 244                 mtd = kzalloc(sizeof(struct DiskOnChip) + sizeof(struct mtd_info), GFP_KERNEL);
 245                 if (!mtd) {
 246                         printk(KERN_WARNING "Cannot allocate memory for data structures. Dropping.\n");
 247                         iounmap(docptr);
 248                         return;
 249                 }
 250
 251                 this = (struct DiskOnChip *)(&mtd[1]);
 252                 mtd->priv = this;
 253                 this->virtadr = docptr;
 254                 this->physadr = physadr;
 255                 this->ChipID = ChipID;
 256                 sprintf(namebuf, "with ChipID %2.2X", ChipID);
 257
 258                 switch(ChipID) {
 259                 case DOC_ChipID_Doc2kTSOP:
 260                         name="2000 TSOP";
 261                         initroutine = symbol_request(DoC2k_init);
 262                         break;
 263
 264                 case DOC_ChipID_Doc2k:
 265                         name="2000";
 266                         initroutine = symbol_request(DoC2k_init);
 267                         break;
 268
 269                 case DOC_ChipID_DocMil:
 270                         name="Millennium";
 271 #ifdef DOC_SINGLE_DRIVER
 272                         initroutine = symbol_request(DoC2k_init);
 273 #else
 274                         initroutine = symbol_request(DoCMil_init);
 275 #endif /* DOC_SINGLE_DRIVER */
 276                         break;
 277
 278                 case DOC_ChipID_DocMilPlus16:
 279                 case DOC_ChipID_DocMilPlus32:
 280                         name="MillenniumPlus";
 281                         initroutine = symbol_request(DoCMilPlus_init);
 282                         break;
 283                 }
 284
 285                 if (initroutine) {
 286                         (*initroutine)(mtd);
 287                         symbol_put_addr(initroutine);
 288                         return;
 289                 }
 290                 printk(KERN_NOTICE "Cannot find driver for DiskOnChip %s at 0x%lX\n", name, physadr);
 291                 kfree(mtd);
 292         }
 293         iounmap(docptr);
 294 }
 295
 296
 297 /****************************************************************************
 298  *
 299  * Module stuff
 300  *
 301  ****************************************************************************/
 302
 303 static int __init init_doc(void)
 304 {
 305         int i;
 306
 307         if (doc_config_location) {
 308                 printk(KERN_INFO "Using configured DiskOnChip probe address 0x%lx\n", doc_config_location);
 309                 DoC_Probe(doc_config_location);
 310         } else {
 311                 for (i=0; (doc_locations[i] != 0xffffffff); i++) {
 312                         DoC_Probe(doc_locations[i]);
 313                 }
 314         }
 315         /* No banner message any more. Print a message if no DiskOnChip
 316            found, so the user knows we at least tried. */
 317         if (!docfound)
 318                 printk(KERN_INFO "No recognised DiskOnChip devices found\n");
 319         return -EAGAIN;
 320 }
 321
 322 module_init(init_doc);
 323
 324 MODULE_LICENSE("GPL");
 325 MODULE_AUTHOR("David Woodhouse <dwmw2@infradead.org>");
 326 MODULE_DESCRIPTION("Probe code for DiskOnChip 2000 and Millennium devices");
 327