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 1.1.1.1 2007/08/03 18:52:43 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/kernel.h> 44#include <linux/module.h> 45#include <asm/errno.h> 46#include <asm/io.h> 47#include <linux/delay.h> 48#include <linux/slab.h> 49#include <linux/init.h> 50#include <linux/types.h> 51 52#include <linux/mtd/mtd.h> 53#include <linux/mtd/nand.h> 54#include <linux/mtd/doc2000.h> 55#include <linux/mtd/compatmac.h> 56 57/* Where to look for the devices? */ 58#ifndef CONFIG_MTD_DOCPROBE_ADDRESS 59#define CONFIG_MTD_DOCPROBE_ADDRESS 0 60#endif 61 62 63static unsigned long doc_config_location = CONFIG_MTD_DOCPROBE_ADDRESS; 64module_param(doc_config_location, ulong, 0); 65MODULE_PARM_DESC(doc_config_location, "Physical memory address at which to probe for DiskOnChip"); 66 67static unsigned long __initdata doc_locations[] = { 68#if defined(__alpha__) || defined(__i386__) || defined(__x86_64__) 69#ifdef CONFIG_MTD_DOCPROBE_HIGH 70 0xfffc8000, 0xfffca000, 0xfffcc000, 0xfffce000, 71 0xfffd0000, 0xfffd2000, 0xfffd4000, 0xfffd6000, 72 0xfffd8000, 0xfffda000, 0xfffdc000, 0xfffde000, 73 0xfffe0000, 0xfffe2000, 0xfffe4000, 0xfffe6000, 74 0xfffe8000, 0xfffea000, 0xfffec000, 0xfffee000, 75#else /* CONFIG_MTD_DOCPROBE_HIGH */ 76 0xc8000, 0xca000, 0xcc000, 0xce000, 77 0xd0000, 0xd2000, 0xd4000, 0xd6000, 78 0xd8000, 0xda000, 0xdc000, 0xde000, 79 0xe0000, 0xe2000, 0xe4000, 0xe6000, 80 0xe8000, 0xea000, 0xec000, 0xee000, 81#endif /* CONFIG_MTD_DOCPROBE_HIGH */ 82#elif defined(__PPC__) 83 0xe4000000, 84#elif defined(CONFIG_MOMENCO_OCELOT) 85 0x2f000000, 86 0xff000000, 87#elif defined(CONFIG_MOMENCO_OCELOT_G) || defined(CONFIG_MOMENCO_OCELOT_C) 88 0xff000000, 89#else 90#warning Unknown architecture for DiskOnChip. No default probe locations defined 91#endif 92 0xffffffff }; 93 94/* doccheck: Probe a given memory window to see if there's a DiskOnChip present */ 95 96static inline int __init doccheck(void __iomem *potential, unsigned long physadr) 97{ 98 void __iomem *window=potential; 99 unsigned char tmp, tmpb, tmpc, ChipID; 100#ifndef DOC_PASSIVE_PROBE 101 unsigned char tmp2; 102#endif 103 104 /* Routine copied from the Linux DOC driver */ 105 106#ifdef CONFIG_MTD_DOCPROBE_55AA 107 /* Check for 0x55 0xAA signature at beginning of window, 108 this is no longer true once we remove the IPL (for Millennium */ 109 if (ReadDOC(window, Sig1) != 0x55 || ReadDOC(window, Sig2) != 0xaa) 110 return 0; 111#endif /* CONFIG_MTD_DOCPROBE_55AA */ 112 113#ifndef DOC_PASSIVE_PROBE 114 /* It's not possible to cleanly detect the DiskOnChip - the 115 * bootup procedure will put the device into reset mode, and 116 * it's not possible to talk to it without actually writing 117 * to the DOCControl register. So we store the current contents 118 * of the DOCControl register's location, in case we later decide 119 * that it's not a DiskOnChip, and want to put it back how we 120 * found it. 121 */ 122 tmp2 = ReadDOC(window, DOCControl); 123 124 /* Reset the DiskOnChip ASIC */ 125 WriteDOC(DOC_MODE_CLR_ERR | DOC_MODE_MDWREN | DOC_MODE_RESET, 126 window, DOCControl); 127 WriteDOC(DOC_MODE_CLR_ERR | DOC_MODE_MDWREN | DOC_MODE_RESET, 128 window, DOCControl); 129 130 /* Enable the DiskOnChip ASIC */ 131 WriteDOC(DOC_MODE_CLR_ERR | DOC_MODE_MDWREN | DOC_MODE_NORMAL, 132 window, DOCControl); 133 WriteDOC(DOC_MODE_CLR_ERR | DOC_MODE_MDWREN | DOC_MODE_NORMAL, 134 window, DOCControl); 135#endif /* !DOC_PASSIVE_PROBE */ 136 137 /* We need to read the ChipID register four times. For some 138 newer DiskOnChip 2000 units, the first three reads will 139 return the DiskOnChip Millennium ident. Don't ask. */ 140 ChipID = ReadDOC(window, ChipID); 141 142 switch (ChipID) { 143 case DOC_ChipID_Doc2k: 144 /* Check the TOGGLE bit in the ECC register */ 145 tmp = ReadDOC(window, 2k_ECCStatus) & DOC_TOGGLE_BIT; 146 tmpb = ReadDOC(window, 2k_ECCStatus) & DOC_TOGGLE_BIT; 147 tmpc = ReadDOC(window, 2k_ECCStatus) & DOC_TOGGLE_BIT; 148 if (tmp != tmpb && tmp == tmpc) 149 return ChipID; 150 break; 151 152 case DOC_ChipID_DocMil: 153 /* Check for the new 2000 with Millennium ASIC */ 154 ReadDOC(window, ChipID); 155 ReadDOC(window, ChipID); 156 if (ReadDOC(window, ChipID) != DOC_ChipID_DocMil) 157 ChipID = DOC_ChipID_Doc2kTSOP; 158 159 /* Check the TOGGLE bit in the ECC register */ 160 tmp = ReadDOC(window, ECCConf) & DOC_TOGGLE_BIT; 161 tmpb = ReadDOC(window, ECCConf) & DOC_TOGGLE_BIT; 162 tmpc = ReadDOC(window, ECCConf) & DOC_TOGGLE_BIT; 163 if (tmp != tmpb && tmp == tmpc) 164 return ChipID; 165 break; 166 167 case DOC_ChipID_DocMilPlus16: 168 case DOC_ChipID_DocMilPlus32: 169 case 0: 170 /* Possible Millennium+, need to do more checks */ 171#ifndef DOC_PASSIVE_PROBE 172 /* Possibly release from power down mode */ 173 for (tmp = 0; (tmp < 4); tmp++) 174 ReadDOC(window, Mplus_Power); 175 176 /* Reset the DiskOnChip ASIC */ 177 tmp = DOC_MODE_RESET | DOC_MODE_MDWREN | DOC_MODE_RST_LAT | 178 DOC_MODE_BDECT; 179 WriteDOC(tmp, window, Mplus_DOCControl); 180 WriteDOC(~tmp, window, Mplus_CtrlConfirm); 181 182 mdelay(1); 183 /* Enable the DiskOnChip ASIC */ 184 tmp = DOC_MODE_NORMAL | DOC_MODE_MDWREN | DOC_MODE_RST_LAT | 185 DOC_MODE_BDECT; 186 WriteDOC(tmp, window, Mplus_DOCControl); 187 WriteDOC(~tmp, window, Mplus_CtrlConfirm); 188 mdelay(1); 189#endif /* !DOC_PASSIVE_PROBE */ 190 191 ChipID = ReadDOC(window, ChipID); 192 193 switch (ChipID) { 194 case DOC_ChipID_DocMilPlus16: 195 case DOC_ChipID_DocMilPlus32: 196 /* Check the TOGGLE bit in the toggle register */ 197 tmp = ReadDOC(window, Mplus_Toggle) & DOC_TOGGLE_BIT; 198 tmpb = ReadDOC(window, Mplus_Toggle) & DOC_TOGGLE_BIT; 199 tmpc = ReadDOC(window, Mplus_Toggle) & DOC_TOGGLE_BIT; 200 if (tmp != tmpb && tmp == tmpc) 201 return ChipID; 202 default: 203 break; 204 } 205 /* FALL TRHU */ 206 207 default: 208 209#ifdef CONFIG_MTD_DOCPROBE_55AA 210 printk(KERN_DEBUG "Possible DiskOnChip with unknown ChipID %2.2X found at 0x%lx\n", 211 ChipID, physadr); 212#endif 213#ifndef DOC_PASSIVE_PROBE 214 /* Put back the contents of the DOCControl register, in case it's not 215 * actually a DiskOnChip. 216 */ 217 WriteDOC(tmp2, window, DOCControl); 218#endif 219 return 0; 220 } 221 222 printk(KERN_WARNING "DiskOnChip failed TOGGLE test, dropping.\n"); 223 224#ifndef DOC_PASSIVE_PROBE 225 /* Put back the contents of the DOCControl register: it's not a DiskOnChip */ 226 WriteDOC(tmp2, window, DOCControl); 227#endif 228 return 0; 229} 230 231static int docfound; 232 233extern void DoC2k_init(struct mtd_info *); 234extern void DoCMil_init(struct mtd_info *); 235extern void DoCMilPlus_init(struct mtd_info *); 236 237static void __init DoC_Probe(unsigned long physadr) 238{ 239 void __iomem *docptr; 240 struct DiskOnChip *this; 241 struct mtd_info *mtd; 242 int ChipID; 243 char namebuf[15]; 244 char *name = namebuf; 245 void (*initroutine)(struct mtd_info *) = NULL; 246 247 docptr = ioremap(physadr, DOC_IOREMAP_LEN); 248 249 if (!docptr) 250 return; 251 252 if ((ChipID = doccheck(docptr, physadr))) { 253 if (ChipID == DOC_ChipID_Doc2kTSOP) { 254 /* Remove this at your own peril. The hardware driver works but nothing prevents you from erasing bad blocks */ 255 printk(KERN_NOTICE "Refusing to drive DiskOnChip 2000 TSOP until Bad Block Table is correctly supported by INFTL\n"); 256 iounmap(docptr); 257 return; 258 } 259 docfound = 1; 260 mtd = kmalloc(sizeof(struct DiskOnChip) + sizeof(struct mtd_info), GFP_KERNEL); 261 262 if (!mtd) { 263 printk(KERN_WARNING "Cannot allocate memory for data structures. Dropping.\n"); 264 iounmap(docptr); 265 return; 266 } 267 268 this = (struct DiskOnChip *)(&mtd[1]); 269 270 memset((char *)mtd,0, sizeof(struct mtd_info)); 271 memset((char *)this, 0, sizeof(struct DiskOnChip)); 272 273 mtd->priv = this; 274 this->virtadr = docptr; 275 this->physadr = physadr; 276 this->ChipID = ChipID; 277 sprintf(namebuf, "with ChipID %2.2X", ChipID); 278 279 switch(ChipID) { 280 case DOC_ChipID_Doc2kTSOP: 281 name="2000 TSOP"; 282 initroutine = symbol_request(DoC2k_init); 283 break; 284 285 case DOC_ChipID_Doc2k: 286 name="2000"; 287 initroutine = symbol_request(DoC2k_init); 288 break; 289 290 case DOC_ChipID_DocMil: 291 name="Millennium"; 292#ifdef DOC_SINGLE_DRIVER 293 initroutine = symbol_request(DoC2k_init); 294#else 295 initroutine = symbol_request(DoCMil_init); 296#endif /* DOC_SINGLE_DRIVER */ 297 break; 298 299 case DOC_ChipID_DocMilPlus16: 300 case DOC_ChipID_DocMilPlus32: 301 name="MillenniumPlus"; 302 initroutine = symbol_request(DoCMilPlus_init); 303 break; 304 } 305 306 if (initroutine) { 307 (*initroutine)(mtd); 308 symbol_put_addr(initroutine); 309 return; 310 } 311 printk(KERN_NOTICE "Cannot find driver for DiskOnChip %s at 0x%lX\n", name, physadr); 312 kfree(mtd); 313 } 314 iounmap(docptr); 315} 316 317 318/**************************************************************************** 319 * 320 * Module stuff 321 * 322 ****************************************************************************/ 323 324static int __init init_doc(void) 325{ 326 int i; 327 328 if (doc_config_location) { 329 printk(KERN_INFO "Using configured DiskOnChip probe address 0x%lx\n", doc_config_location); 330 DoC_Probe(doc_config_location); 331 } else { 332 for (i=0; (doc_locations[i] != 0xffffffff); i++) { 333 DoC_Probe(doc_locations[i]); 334 } 335 } 336 /* No banner message any more. Print a message if no DiskOnChip 337 found, so the user knows we at least tried. */ 338 if (!docfound) 339 printk(KERN_INFO "No recognised DiskOnChip devices found\n"); 340 return -EAGAIN; 341} 342 343module_init(init_doc); 344 345MODULE_LICENSE("GPL"); 346MODULE_AUTHOR("David Woodhouse <dwmw2@infradead.org>"); 347MODULE_DESCRIPTION("Probe code for DiskOnChip 2000 and Millennium devices"); 348