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 /* $Id: docprobe.c,v 1.46 2005/11/07 11:14:25 gleixner Exp $    */
   8
   9
  10
  11 /* DOC_PASSIVE_PROBE:
  12    In order to ensure that the BIOS checksum is correct at boot time, and
  13    hence that the onboard BIOS extension gets executed, the DiskOnChip
  14    goes into reset mode when it is read sequentially: all registers
  15    return 0xff until the chip is woken up again by writing to the
  16    DOCControl register.
  17
  18    Unfortunately, this means that the probe for the DiskOnChip is unsafe,
  19    because one of the first things it does is write to where it thinks
  20    the DOCControl register should be - which may well be shared memory
  21    for another device. I've had machines which lock up when this is
  22    attempted. Hence the possibility to do a passive probe, which will fail
  23    to detect a chip in reset mode, but is at least guaranteed not to lock
  24    the machine.
  25
  26    If you have this problem, uncomment the following line:
  27 #define DOC_PASSIVE_PROBE
  28 */
  29
  30
  31 /* DOC_SINGLE_DRIVER:
  32    Millennium driver has been merged into DOC2000 driver.
  33
  34    The old Millennium-only driver has been retained just in case there
  35    are problems with the new code. If the combined driver doesn't work
  36    for you, you can try the old one by undefining DOC_SINGLE_DRIVER
  37    below and also enabling it in your configuration. If this fixes the
  38    problems, please send a report to the MTD mailing list at
  39    <linux-mtd@lists.infradead.org>.
  40 */
  41 #define DOC_SINGLE_DRIVER
  42
  43 #include <linux/config.h>
  44 #include <linux/kernel.h>
  45 #include <linux/module.h>
  46 #include <asm/errno.h>
  47 #include <asm/io.h>
  48 #include <linux/delay.h>
  49 #include <linux/slab.h>
  50 #include <linux/init.h>
  51 #include <linux/types.h>
  52
  53 #include <linux/mtd/mtd.h>
  54 #include <linux/mtd/nand.h>
  55 #include <linux/mtd/doc2000.h>
  56 #include <linux/mtd/compatmac.h>
  57
  58 /* Where to look for the devices? */
  59 #ifndef CONFIG_MTD_DOCPROBE_ADDRESS
  60 #define CONFIG_MTD_DOCPROBE_ADDRESS 0
  61 #endif
  62
  63
  64 static unsigned long doc_config_location = CONFIG_MTD_DOCPROBE_ADDRESS;
  65 module_param(doc_config_location, ulong, 0);
  66 MODULE_PARM_DESC(doc_config_location, "Physical memory address at which to probe for DiskOnChip");
  67
  68 static unsigned long __initdata doc_locations[] = {
  69 #if defined (__alpha__) || defined(__i386__) || defined(__x86_64__)
  70 #ifdef CONFIG_MTD_DOCPROBE_HIGH
  71         0xfffc8000, 0xfffca000, 0xfffcc000, 0xfffce000,
  72         0xfffd0000, 0xfffd2000, 0xfffd4000, 0xfffd6000,
  73         0xfffd8000, 0xfffda000, 0xfffdc000, 0xfffde000,
  74         0xfffe0000, 0xfffe2000, 0xfffe4000, 0xfffe6000,
  75         0xfffe8000, 0xfffea000, 0xfffec000, 0xfffee000,
  76 #else /*  CONFIG_MTD_DOCPROBE_HIGH */
  77         0xc8000, 0xca000, 0xcc000, 0xce000,
  78         0xd0000, 0xd2000, 0xd4000, 0xd6000,
  79         0xd8000, 0xda000, 0xdc000, 0xde000,
  80         0xe0000, 0xe2000, 0xe4000, 0xe6000,
  81         0xe8000, 0xea000, 0xec000, 0xee000,
  82 #endif /*  CONFIG_MTD_DOCPROBE_HIGH */
  83 #elif defined(__PPC__)
  84         0xe4000000,
  85 #elif defined(CONFIG_MOMENCO_OCELOT)
  86         0x2f000000,
  87         0xff000000,
  88 #elif defined(CONFIG_MOMENCO_OCELOT_G) || defined (CONFIG_MOMENCO_OCELOT_C)
  89         0xff000000,
  90 ##else
  91 #warning Unknown architecture for DiskOnChip. No default probe locations defined
  92 #endif
  93         0xffffffff };
  94
  95 /* doccheck: Probe a given memory window to see if there's a DiskOnChip present */
  96
  97 static inline int __init doccheck(void __iomem *potential, unsigned long physadr)
  98 {
  99         void __iomem *window=potential;
 100         unsigned char tmp, tmpb, tmpc, ChipID;
 101 #ifndef DOC_PASSIVE_PROBE
 102         unsigned char tmp2;
 103 #endif
 104
 105         /* Routine copied from the Linux DOC driver */
 106
 107 #ifdef CONFIG_MTD_DOCPROBE_55AA
 108         /* Check for 0x55 0xAA signature at beginning of window,
 109            this is no longer true once we remove the IPL (for Millennium */
 110         if (ReadDOC(window, Sig1) != 0x55 || ReadDOC(window, Sig2) != 0xaa)
 111                 return 0;
 112 #endif /* CONFIG_MTD_DOCPROBE_55AA */
 113
 114 #ifndef DOC_PASSIVE_PROBE
 115         /* It's not possible to cleanly detect the DiskOnChip - the
 116          * bootup procedure will put the device into reset mode, and
 117          * it's not possible to talk to it without actually writing
 118          * to the DOCControl register. So we store the current contents
 119          * of the DOCControl register's location, in case we later decide
 120          * that it's not a DiskOnChip, and want to put it back how we
 121          * found it.
 122          */
 123         tmp2 = ReadDOC(window, DOCControl);
 124
 125         /* Reset the DiskOnChip ASIC */
 126         WriteDOC(DOC_MODE_CLR_ERR | DOC_MODE_MDWREN | DOC_MODE_RESET,
 127                  window, DOCControl);
 128         WriteDOC(DOC_MODE_CLR_ERR | DOC_MODE_MDWREN | DOC_MODE_RESET,
 129                  window, DOCControl);
 130
 131         /* Enable the DiskOnChip ASIC */
 132         WriteDOC(DOC_MODE_CLR_ERR | DOC_MODE_MDWREN | DOC_MODE_NORMAL,
 133                  window, DOCControl);
 134         WriteDOC(DOC_MODE_CLR_ERR | DOC_MODE_MDWREN | DOC_MODE_NORMAL,
 135                  window, DOCControl);
 136 #endif /* !DOC_PASSIVE_PROBE */
 137
 138         /* We need to read the ChipID register four times. For some
 139            newer DiskOnChip 2000 units, the first three reads will
 140            return the DiskOnChip Millennium ident. Don't ask. */
 141         ChipID = ReadDOC(window, ChipID);
 142
 143         switch (ChipID) {
 144         case DOC_ChipID_Doc2k:
 145                 /* Check the TOGGLE bit in the ECC register */
 146                 tmp  = ReadDOC(window, 2k_ECCStatus) & DOC_TOGGLE_BIT;
 147                 tmpb = ReadDOC(window, 2k_ECCStatus) & DOC_TOGGLE_BIT;
 148                 tmpc = ReadDOC(window, 2k_ECCStatus) & DOC_TOGGLE_BIT;
 149                 if (tmp != tmpb && tmp == tmpc)
 150                                 return ChipID;
 151                 break;
 152
 153         case DOC_ChipID_DocMil:
 154                 /* Check for the new 2000 with Millennium ASIC */
 155                 ReadDOC(window, ChipID);
 156                 ReadDOC(window, ChipID);
 157                 if (ReadDOC(window, ChipID) != DOC_ChipID_DocMil)
 158                         ChipID = DOC_ChipID_Doc2kTSOP;
 159
 160                 /* Check the TOGGLE bit in the ECC register */
 161                 tmp  = ReadDOC(window, ECCConf) & DOC_TOGGLE_BIT;
 162                 tmpb = ReadDOC(window, ECCConf) & DOC_TOGGLE_BIT;
 163                 tmpc = ReadDOC(window, ECCConf) & DOC_TOGGLE_BIT;
 164                 if (tmp != tmpb && tmp == tmpc)
 165                                 return ChipID;
 166                 break;
 167
 168         case DOC_ChipID_DocMilPlus16:
 169         case DOC_ChipID_DocMilPlus32:
 170         case 0:
 171                 /* Possible Millennium+, need to do more checks */
 172 #ifndef DOC_PASSIVE_PROBE
 173                 /* Possibly release from power down mode */
 174                 for (tmp = 0; (tmp < 4); tmp++)
 175                         ReadDOC(window, Mplus_Power);
 176
 177                 /* Reset the DiskOnChip ASIC */
 178                 tmp = DOC_MODE_RESET | DOC_MODE_MDWREN | DOC_MODE_RST_LAT |
 179                         DOC_MODE_BDECT;
 180                 WriteDOC(tmp, window, Mplus_DOCControl);
 181                 WriteDOC(~tmp, window, Mplus_CtrlConfirm);
 182
 183                 mdelay(1);
 184                 /* Enable the DiskOnChip ASIC */
 185                 tmp = DOC_MODE_NORMAL | DOC_MODE_MDWREN | DOC_MODE_RST_LAT |
 186                         DOC_MODE_BDECT;
 187                 WriteDOC(tmp, window, Mplus_DOCControl);
 188                 WriteDOC(~tmp, window, Mplus_CtrlConfirm);
 189                 mdelay(1);
 190 #endif /* !DOC_PASSIVE_PROBE */
 191
 192                 ChipID = ReadDOC(window, ChipID);
 193
 194                 switch (ChipID) {
 195                 case DOC_ChipID_DocMilPlus16:
 196                 case DOC_ChipID_DocMilPlus32:
 197                         /* Check the TOGGLE bit in the toggle register */
 198                         tmp  = ReadDOC(window, Mplus_Toggle) & DOC_TOGGLE_BIT;
 199                         tmpb = ReadDOC(window, Mplus_Toggle) & DOC_TOGGLE_BIT;
 200                         tmpc = ReadDOC(window, Mplus_Toggle) & DOC_TOGGLE_BIT;
 201                         if (tmp != tmpb && tmp == tmpc)
 202                                         return ChipID;
 203                 default:
 204                         break;
 205                 }
 206                 /* FALL TRHU */
 207
 208         default:
 209
 210 #ifdef CONFIG_MTD_DOCPROBE_55AA
 211                 printk(KERN_DEBUG "Possible DiskOnChip with unknown ChipID %2.2X found at 0x%lx\n",
 212                        ChipID, physadr);
 213 #endif
 214 #ifndef DOC_PASSIVE_PROBE
 215                 /* Put back the contents of the DOCControl register, in case it's not
 216                  * actually a DiskOnChip.
 217                  */
 218                 WriteDOC(tmp2, window, DOCControl);
 219 #endif
 220                 return 0;
 221         }
 222
 223         printk(KERN_WARNING "DiskOnChip failed TOGGLE test, dropping.\n");
 224
 225 #ifndef DOC_PASSIVE_PROBE
 226         /* Put back the contents of the DOCControl register: it's not a DiskOnChip */
 227         WriteDOC(tmp2, window, DOCControl);
 228 #endif
 229         return 0;
 230 }
 231
 232 static int docfound;
 233
 234 static void __init DoC_Probe(unsigned long physadr)
 235 {
 236         void __iomem *docptr;
 237         struct DiskOnChip *this;
 238         struct mtd_info *mtd;
 239         int ChipID;
 240         char namebuf[15];
 241         char *name = namebuf;
 242         char *im_funcname = NULL;
 243         char *im_modname = NULL;
 244         void (*initroutine)(struct mtd_info *) = NULL;
 245
 246         docptr = ioremap(physadr, DOC_IOREMAP_LEN);
 247
 248         if (!docptr)
 249                 return;
 250
 251         if ((ChipID = doccheck(docptr, physadr))) {
 252                 if (ChipID == DOC_ChipID_Doc2kTSOP) {
 253                         /* Remove this at your own peril. The hardware driver works but nothing prevents you from erasing bad blocks */
 254                         printk(KERN_NOTICE "Refusing to drive DiskOnChip 2000 TSOP until Bad Block Table is correctly supported by INFTL\n");
 255                         iounmap(docptr);
 256                         return;
 257                 }
 258                 docfound = 1;
 259                 mtd = kmalloc(sizeof(struct DiskOnChip) + sizeof(struct mtd_info), GFP_KERNEL);
 260
 261                 if (!mtd) {
 262                         printk(KERN_WARNING "Cannot allocate memory for data structures. Dropping.\n");
 263                         iounmap(docptr);
 264                         return;
 265                 }
 266
 267                 this = (struct DiskOnChip *)(&mtd[1]);
 268
 269                 memset((char *)mtd,0, sizeof(struct mtd_info));
 270                 memset((char *)this, 0, sizeof(struct DiskOnChip));
 271
 272                 mtd->priv = this;
 273                 this->virtadr = docptr;
 274                 this->physadr = physadr;
 275                 this->ChipID = ChipID;
 276                 sprintf(namebuf, "with ChipID %2.2X", ChipID);
 277
 278                 switch(ChipID) {
 279                 case DOC_ChipID_Doc2kTSOP:
 280                         name="2000 TSOP";
 281                         im_funcname = "DoC2k_init";
 282                         im_modname = "doc2000";
 283                         break;
 284
 285                 case DOC_ChipID_Doc2k:
 286                         name="2000";
 287                         im_funcname = "DoC2k_init";
 288                         im_modname = "doc2000";
 289                         break;
 290
 291                 case DOC_ChipID_DocMil:
 292                         name="Millennium";
 293 #ifdef DOC_SINGLE_DRIVER
 294                         im_funcname = "DoC2k_init";
 295                         im_modname = "doc2000";
 296 #else
 297                         im_funcname = "DoCMil_init";
 298                         im_modname = "doc2001";
 299 #endif /* DOC_SINGLE_DRIVER */
 300                         break;
 301
 302                 case DOC_ChipID_DocMilPlus16:
 303                 case DOC_ChipID_DocMilPlus32:
 304                         name="MillenniumPlus";
 305                         im_funcname = "DoCMilPlus_init";
 306                         im_modname = "doc2001plus";
 307                         break;
 308                 }
 309
 310                 if (im_funcname)
 311                         initroutine = inter_module_get_request(im_funcname, im_modname);
 312
 313                 if (initroutine) {
 314                         (*initroutine)(mtd);
 315                         inter_module_put(im_funcname);
 316                         return;
 317                 }
 318                 printk(KERN_NOTICE "Cannot find driver for DiskOnChip %s at 0x%lX\n", name, physadr);
 319                 kfree(mtd);
 320         }
 321         iounmap(docptr);
 322 }
 323
 324
 325 /****************************************************************************
 326  *
 327  * Module stuff
 328  *
 329  ****************************************************************************/
 330
 331 static int __init init_doc(void)
 332 {
 333         int i;
 334
 335         if (doc_config_location) {
 336                 printk(KERN_INFO "Using configured DiskOnChip probe address 0x%lx\n", doc_config_location);
 337                 DoC_Probe(doc_config_location);
 338         } else {
 339                 for (i=0; (doc_locations[i] != 0xffffffff); i++) {
 340                         DoC_Probe(doc_locations[i]);
 341                 }
 342         }
 343         /* No banner message any more. Print a message if no DiskOnChip
 344            found, so the user knows we at least tried. */
 345         if (!docfound)
 346                 printk(KERN_INFO "No recognised DiskOnChip devices found\n");
 347         return -EAGAIN;
 348 }
 349
 350 module_init(init_doc);
 351
 352 MODULE_LICENSE("GPL");
 353 MODULE_AUTHOR("David Woodhouse <dwmw2@infradead.org>");
 354 MODULE_DESCRIPTION("Probe code for DiskOnChip 2000 and Millennium devices");
 355