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