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/kernel.h>
44 #include <linux/module.h>
45 #include <asm/errno.h>
47 #include <linux/delay.h>
48 #include <linux/slab.h>
49 #include <linux/init.h>
50 #include <linux/types.h>
52 #include <linux/mtd/mtd.h>
53 #include <linux/mtd/nand.h>
54 #include <linux/mtd/doc2000.h>
55 #include <linux/mtd/compatmac.h>
57 /* Where to look for the devices? */
58 #ifndef CONFIG_MTD_DOCPROBE_ADDRESS
59 #define CONFIG_MTD_DOCPROBE_ADDRESS 0
63 static unsigned long doc_config_location = CONFIG_MTD_DOCPROBE_ADDRESS;
64 module_param(doc_config_location, ulong, 0);
65 MODULE_PARM_DESC(doc_config_location, "Physical memory address at which to probe for DiskOnChip");
67 static 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__)
84 #elif defined(CONFIG_MOMENCO_OCELOT)
88 #warning Unknown architecture for DiskOnChip. No default probe locations defined
92 /* doccheck: Probe a given memory window to see if there's a DiskOnChip present */
94 static inline int __init doccheck(void __iomem *potential, unsigned long physadr)
96 void __iomem *window=potential;
97 unsigned char tmp, tmpb, tmpc, ChipID;
98 #ifndef DOC_PASSIVE_PROBE
102 /* Routine copied from the Linux DOC driver */
104 #ifdef CONFIG_MTD_DOCPROBE_55AA
105 /* Check for 0x55 0xAA signature at beginning of window,
106 this is no longer true once we remove the IPL (for Millennium */
107 if (ReadDOC(window, Sig1) != 0x55 || ReadDOC(window, Sig2) != 0xaa)
109 #endif /* CONFIG_MTD_DOCPROBE_55AA */
111 #ifndef DOC_PASSIVE_PROBE
112 /* It's not possible to cleanly detect the DiskOnChip - the
113 * bootup procedure will put the device into reset mode, and
114 * it's not possible to talk to it without actually writing
115 * to the DOCControl register. So we store the current contents
116 * of the DOCControl register's location, in case we later decide
117 * that it's not a DiskOnChip, and want to put it back how we
120 tmp2 = ReadDOC(window, DOCControl);
122 /* Reset the DiskOnChip ASIC */
123 WriteDOC(DOC_MODE_CLR_ERR | DOC_MODE_MDWREN | DOC_MODE_RESET,
125 WriteDOC(DOC_MODE_CLR_ERR | DOC_MODE_MDWREN | DOC_MODE_RESET,
128 /* Enable the DiskOnChip ASIC */
129 WriteDOC(DOC_MODE_CLR_ERR | DOC_MODE_MDWREN | DOC_MODE_NORMAL,
131 WriteDOC(DOC_MODE_CLR_ERR | DOC_MODE_MDWREN | DOC_MODE_NORMAL,
133 #endif /* !DOC_PASSIVE_PROBE */
135 /* We need to read the ChipID register four times. For some
136 newer DiskOnChip 2000 units, the first three reads will
137 return the DiskOnChip Millennium ident. Don't ask. */
138 ChipID = ReadDOC(window, ChipID);
141 case DOC_ChipID_Doc2k:
142 /* Check the TOGGLE bit in the ECC register */
143 tmp = ReadDOC(window, 2k_ECCStatus) & DOC_TOGGLE_BIT;
144 tmpb = ReadDOC(window, 2k_ECCStatus) & DOC_TOGGLE_BIT;
145 tmpc = ReadDOC(window, 2k_ECCStatus) & DOC_TOGGLE_BIT;
146 if (tmp != tmpb && tmp == tmpc)
150 case DOC_ChipID_DocMil:
151 /* Check for the new 2000 with Millennium ASIC */
152 ReadDOC(window, ChipID);
153 ReadDOC(window, ChipID);
154 if (ReadDOC(window, ChipID) != DOC_ChipID_DocMil)
155 ChipID = DOC_ChipID_Doc2kTSOP;
157 /* Check the TOGGLE bit in the ECC register */
158 tmp = ReadDOC(window, ECCConf) & DOC_TOGGLE_BIT;
159 tmpb = ReadDOC(window, ECCConf) & DOC_TOGGLE_BIT;
160 tmpc = ReadDOC(window, ECCConf) & DOC_TOGGLE_BIT;
161 if (tmp != tmpb && tmp == tmpc)
165 case DOC_ChipID_DocMilPlus16:
166 case DOC_ChipID_DocMilPlus32:
168 /* Possible Millennium+, need to do more checks */
169 #ifndef DOC_PASSIVE_PROBE
170 /* Possibly release from power down mode */
171 for (tmp = 0; (tmp < 4); tmp++)
172 ReadDOC(window, Mplus_Power);
174 /* Reset the DiskOnChip ASIC */
175 tmp = DOC_MODE_RESET | DOC_MODE_MDWREN | DOC_MODE_RST_LAT |
177 WriteDOC(tmp, window, Mplus_DOCControl);
178 WriteDOC(~tmp, window, Mplus_CtrlConfirm);
181 /* Enable the DiskOnChip ASIC */
182 tmp = DOC_MODE_NORMAL | DOC_MODE_MDWREN | DOC_MODE_RST_LAT |
184 WriteDOC(tmp, window, Mplus_DOCControl);
185 WriteDOC(~tmp, window, Mplus_CtrlConfirm);
187 #endif /* !DOC_PASSIVE_PROBE */
189 ChipID = ReadDOC(window, ChipID);
192 case DOC_ChipID_DocMilPlus16:
193 case DOC_ChipID_DocMilPlus32:
194 /* Check the TOGGLE bit in the toggle register */
195 tmp = ReadDOC(window, Mplus_Toggle) & DOC_TOGGLE_BIT;
196 tmpb = ReadDOC(window, Mplus_Toggle) & DOC_TOGGLE_BIT;
197 tmpc = ReadDOC(window, Mplus_Toggle) & DOC_TOGGLE_BIT;
198 if (tmp != tmpb && tmp == tmpc)
207 #ifdef CONFIG_MTD_DOCPROBE_55AA
208 printk(KERN_DEBUG "Possible DiskOnChip with unknown ChipID %2.2X found at 0x%lx\n",
211 #ifndef DOC_PASSIVE_PROBE
212 /* Put back the contents of the DOCControl register, in case it's not
213 * actually a DiskOnChip.
215 WriteDOC(tmp2, window, DOCControl);
220 printk(KERN_WARNING "DiskOnChip failed TOGGLE test, dropping.\n");
222 #ifndef DOC_PASSIVE_PROBE
223 /* Put back the contents of the DOCControl register: it's not a DiskOnChip */
224 WriteDOC(tmp2, window, DOCControl);
231 extern void DoC2k_init(struct mtd_info *);
232 extern void DoCMil_init(struct mtd_info *);
233 extern void DoCMilPlus_init(struct mtd_info *);
235 static void __init DoC_Probe(unsigned long physadr)
237 void __iomem *docptr;
238 struct DiskOnChip *this;
239 struct mtd_info *mtd;
242 char *name = namebuf;
243 void (*initroutine)(struct mtd_info *) = NULL;
245 docptr = ioremap(physadr, DOC_IOREMAP_LEN);
250 if ((ChipID = doccheck(docptr, physadr))) {
251 if (ChipID == DOC_ChipID_Doc2kTSOP) {
252 /* Remove this at your own peril. The hardware driver works but nothing prevents you from erasing bad blocks */
253 printk(KERN_NOTICE "Refusing to drive DiskOnChip 2000 TSOP until Bad Block Table is correctly supported by INFTL\n");
258 mtd = kmalloc(sizeof(struct DiskOnChip) + sizeof(struct mtd_info), GFP_KERNEL);
261 printk(KERN_WARNING "Cannot allocate memory for data structures. Dropping.\n");
266 this = (struct DiskOnChip *)(&mtd[1]);
268 memset((char *)mtd,0, sizeof(struct mtd_info));
269 memset((char *)this, 0, sizeof(struct DiskOnChip));
272 this->virtadr = docptr;
273 this->physadr = physadr;
274 this->ChipID = ChipID;
275 sprintf(namebuf, "with ChipID %2.2X", ChipID);
278 case DOC_ChipID_Doc2kTSOP:
280 initroutine = symbol_request(DoC2k_init);
283 case DOC_ChipID_Doc2k:
285 initroutine = symbol_request(DoC2k_init);
288 case DOC_ChipID_DocMil:
290 #ifdef DOC_SINGLE_DRIVER
291 initroutine = symbol_request(DoC2k_init);
293 initroutine = symbol_request(DoCMil_init);
294 #endif /* DOC_SINGLE_DRIVER */
297 case DOC_ChipID_DocMilPlus16:
298 case DOC_ChipID_DocMilPlus32:
299 name="MillenniumPlus";
300 initroutine = symbol_request(DoCMilPlus_init);
306 symbol_put_addr(initroutine);
309 printk(KERN_NOTICE "Cannot find driver for DiskOnChip %s at 0x%lX\n", name, physadr);
316 /****************************************************************************
320 ****************************************************************************/
322 static int __init init_doc(void)
326 if (doc_config_location) {
327 printk(KERN_INFO "Using configured DiskOnChip probe address 0x%lx\n", doc_config_location);
328 DoC_Probe(doc_config_location);
330 for (i=0; (doc_locations[i] != 0xffffffff); i++) {
331 DoC_Probe(doc_locations[i]);
334 /* No banner message any more. Print a message if no DiskOnChip
335 found, so the user knows we at least tried. */
337 printk(KERN_INFO "No recognised DiskOnChip devices found\n");
341 module_init(init_doc);
343 MODULE_LICENSE("GPL");
344 MODULE_AUTHOR("David Woodhouse <dwmw2@infradead.org>");
345 MODULE_DESCRIPTION("Probe code for DiskOnChip 2000 and Millennium devices");