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> */
7 /* $Id: docprobe.c,v 1.46 2005/11/07 11:14:25 gleixner Exp $ */
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
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
26 If you have this problem, uncomment the following line:
27 #define DOC_PASSIVE_PROBE
32 Millennium driver has been merged into DOC2000 driver.
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>.
41 #define DOC_SINGLE_DRIVER
43 #include <linux/config.h>
44 #include <linux/kernel.h>
45 #include <linux/module.h>
46 #include <asm/errno.h>
48 #include <linux/delay.h>
49 #include <linux/slab.h>
50 #include <linux/init.h>
51 #include <linux/types.h>
53 #include <linux/mtd/mtd.h>
54 #include <linux/mtd/nand.h>
55 #include <linux/mtd/doc2000.h>
56 #include <linux/mtd/compatmac.h>
58 /* Where to look for the devices? */
59 #ifndef CONFIG_MTD_DOCPROBE_ADDRESS
60 #define CONFIG_MTD_DOCPROBE_ADDRESS 0
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");
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__)
85 #elif defined(CONFIG_MOMENCO_OCELOT)
88 #elif defined(CONFIG_MOMENCO_OCELOT_G) || defined (CONFIG_MOMENCO_OCELOT_C)
91 #warning Unknown architecture for DiskOnChip. No default probe locations defined
95 /* doccheck: Probe a given memory window to see if there's a DiskOnChip present */
97 static inline int __init doccheck(void __iomem *potential, unsigned long physadr)
99 void __iomem *window=potential;
100 unsigned char tmp, tmpb, tmpc, ChipID;
101 #ifndef DOC_PASSIVE_PROBE
105 /* Routine copied from the Linux DOC driver */
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)
112 #endif /* CONFIG_MTD_DOCPROBE_55AA */
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
123 tmp2 = ReadDOC(window, DOCControl);
125 /* Reset the DiskOnChip ASIC */
126 WriteDOC(DOC_MODE_CLR_ERR | DOC_MODE_MDWREN | DOC_MODE_RESET,
128 WriteDOC(DOC_MODE_CLR_ERR | DOC_MODE_MDWREN | DOC_MODE_RESET,
131 /* Enable the DiskOnChip ASIC */
132 WriteDOC(DOC_MODE_CLR_ERR | DOC_MODE_MDWREN | DOC_MODE_NORMAL,
134 WriteDOC(DOC_MODE_CLR_ERR | DOC_MODE_MDWREN | DOC_MODE_NORMAL,
136 #endif /* !DOC_PASSIVE_PROBE */
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);
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)
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;
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)
168 case DOC_ChipID_DocMilPlus16:
169 case DOC_ChipID_DocMilPlus32:
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);
177 /* Reset the DiskOnChip ASIC */
178 tmp = DOC_MODE_RESET | DOC_MODE_MDWREN | DOC_MODE_RST_LAT |
180 WriteDOC(tmp, window, Mplus_DOCControl);
181 WriteDOC(~tmp, window, Mplus_CtrlConfirm);
184 /* Enable the DiskOnChip ASIC */
185 tmp = DOC_MODE_NORMAL | DOC_MODE_MDWREN | DOC_MODE_RST_LAT |
187 WriteDOC(tmp, window, Mplus_DOCControl);
188 WriteDOC(~tmp, window, Mplus_CtrlConfirm);
190 #endif /* !DOC_PASSIVE_PROBE */
192 ChipID = ReadDOC(window, 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)
210 #ifdef CONFIG_MTD_DOCPROBE_55AA
211 printk(KERN_DEBUG "Possible DiskOnChip with unknown ChipID %2.2X found at 0x%lx\n",
214 #ifndef DOC_PASSIVE_PROBE
215 /* Put back the contents of the DOCControl register, in case it's not
216 * actually a DiskOnChip.
218 WriteDOC(tmp2, window, DOCControl);
223 printk(KERN_WARNING "DiskOnChip failed TOGGLE test, dropping.\n");
225 #ifndef DOC_PASSIVE_PROBE
226 /* Put back the contents of the DOCControl register: it's not a DiskOnChip */
227 WriteDOC(tmp2, window, DOCControl);
234 #ifdef CONFIG_MTD_DOC2000
235 extern void DoC2k_init(struct mtd_info *);
236 #define doc2k_initfunc (&DoC2k_init)
238 #define doc2k_initfunc NULL
241 #ifdef CONFIG_MTD_DOC2001
242 extern void DoCMil_init(struct mtd_info *);
243 #define docmil_initfunc (&DoCMil_init)
245 #define docmil_initfunc NULL
248 #ifdef CONFIG_MTD_DOC2001PLUS
249 extern void DoCMilPlus_init(struct mtd_info *);
250 #define docmplus_initfunc (&DoCMilPlus_init)
252 #define docmplus_initfunc NULL
255 static void __init DoC_Probe(unsigned long physadr)
257 void __iomem *docptr;
258 struct DiskOnChip *this;
259 struct mtd_info *mtd;
262 char *name = namebuf;
263 char *im_funcname = NULL;
264 char *im_modname = NULL;
265 void (*initroutine)(struct mtd_info *) = NULL;
267 docptr = ioremap(physadr, DOC_IOREMAP_LEN);
272 if ((ChipID = doccheck(docptr, physadr))) {
273 if (ChipID == DOC_ChipID_Doc2kTSOP) {
274 /* Remove this at your own peril. The hardware driver works but nothing prevents you from erasing bad blocks */
275 printk(KERN_NOTICE "Refusing to drive DiskOnChip 2000 TSOP until Bad Block Table is correctly supported by INFTL\n");
280 mtd = kmalloc(sizeof(struct DiskOnChip) + sizeof(struct mtd_info), GFP_KERNEL);
283 printk(KERN_WARNING "Cannot allocate memory for data structures. Dropping.\n");
288 this = (struct DiskOnChip *)(&mtd[1]);
290 memset((char *)mtd,0, sizeof(struct mtd_info));
291 memset((char *)this, 0, sizeof(struct DiskOnChip));
294 this->virtadr = docptr;
295 this->physadr = physadr;
296 this->ChipID = ChipID;
297 sprintf(namebuf, "with ChipID %2.2X", ChipID);
300 case DOC_ChipID_Doc2kTSOP:
302 im_funcname = "DoC2k_init";
303 im_modname = "doc2000";
304 initroutine = doc2k_initfunc;
307 case DOC_ChipID_Doc2k:
309 im_funcname = "DoC2k_init";
310 im_modname = "doc2000";
311 initroutine = doc2k_initfunc;
314 case DOC_ChipID_DocMil:
316 #ifdef DOC_SINGLE_DRIVER
317 im_funcname = "DoC2k_init";
318 im_modname = "doc2000";
319 initroutine = doc2k_initfunc;
321 im_funcname = "DoCMil_init";
322 im_modname = "doc2001";
323 initroutine = docmil_initfunc;
324 #endif /* DOC_SINGLE_DRIVER */
327 case DOC_ChipID_DocMilPlus16:
328 case DOC_ChipID_DocMilPlus32:
329 name="MillenniumPlus";
330 im_funcname = "DoCMilPlus_init";
331 im_modname = "doc2001plus";
332 initroutine = docmplus_initfunc;
336 #ifdef CONFIG_MODULES
337 if (im_funcname && !initroutine)
338 initroutine = __symbol_get(im_funcname);
339 if (im_funcname && !initroutine) {
340 request_module(im_modname);
341 initroutine = __symbol_get(im_funcname);
346 symbol_put_addr(initroutine);
349 printk(KERN_NOTICE "Cannot find driver for DiskOnChip %s at 0x%lX\n", name, physadr);
356 /****************************************************************************
360 ****************************************************************************/
362 static int __init init_doc(void)
366 if (doc_config_location) {
367 printk(KERN_INFO "Using configured DiskOnChip probe address 0x%lx\n", doc_config_location);
368 DoC_Probe(doc_config_location);
370 for (i=0; (doc_locations[i] != 0xffffffff); i++) {
371 DoC_Probe(doc_locations[i]);
374 /* No banner message any more. Print a message if no DiskOnChip
375 found, so the user knows we at least tried. */
377 printk(KERN_INFO "No recognised DiskOnChip devices found\n");
381 module_init(init_doc);
383 MODULE_LICENSE("GPL");
384 MODULE_AUTHOR("David Woodhouse <dwmw2@infradead.org>");
385 MODULE_DESCRIPTION("Probe code for DiskOnChip 2000 and Millennium devices");