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
doccheck(void __iomem * potential,unsigned long physadr)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
DoC_Probe(unsigned long physadr)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
init_doc(void)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
328