Linux 2.6.20.7
[linux/fpc-iii.git] / drivers / mtd / devices / docprobe.c
blob78872c3f3760d63f191deed477a7307bb5d4c505
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 $ */
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.
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.
26 If you have this problem, uncomment the following line:
27 #define DOC_PASSIVE_PROBE
31 /* DOC_SINGLE_DRIVER:
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>
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>
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
60 #endif
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__)
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 };
94 /* doccheck: Probe a given memory window to see if there's a DiskOnChip present */
96 static inline int __init doccheck(void __iomem *potential, unsigned long physadr)
98 void __iomem *window=potential;
99 unsigned char tmp, tmpb, tmpc, ChipID;
100 #ifndef DOC_PASSIVE_PROBE
101 unsigned char tmp2;
102 #endif
104 /* Routine copied from the Linux DOC driver */
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 */
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.
122 tmp2 = ReadDOC(window, DOCControl);
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);
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 */
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);
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;
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;
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;
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);
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);
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 */
191 ChipID = ReadDOC(window, ChipID);
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;
205 /* FALL TRHU */
207 default:
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.
217 WriteDOC(tmp2, window, DOCControl);
218 #endif
219 return 0;
222 printk(KERN_WARNING "DiskOnChip failed TOGGLE test, dropping.\n");
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;
231 static int docfound;
233 extern void DoC2k_init(struct mtd_info *);
234 extern void DoCMil_init(struct mtd_info *);
235 extern void DoCMilPlus_init(struct mtd_info *);
237 static void __init DoC_Probe(unsigned long physadr)
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;
247 docptr = ioremap(physadr, DOC_IOREMAP_LEN);
249 if (!docptr)
250 return;
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;
259 docfound = 1;
260 mtd = kmalloc(sizeof(struct DiskOnChip) + sizeof(struct mtd_info), GFP_KERNEL);
262 if (!mtd) {
263 printk(KERN_WARNING "Cannot allocate memory for data structures. Dropping.\n");
264 iounmap(docptr);
265 return;
268 this = (struct DiskOnChip *)(&mtd[1]);
270 memset((char *)mtd,0, sizeof(struct mtd_info));
271 memset((char *)this, 0, sizeof(struct DiskOnChip));
273 mtd->priv = this;
274 this->virtadr = docptr;
275 this->physadr = physadr;
276 this->ChipID = ChipID;
277 sprintf(namebuf, "with ChipID %2.2X", ChipID);
279 switch(ChipID) {
280 case DOC_ChipID_Doc2kTSOP:
281 name="2000 TSOP";
282 initroutine = symbol_request(DoC2k_init);
283 break;
285 case DOC_ChipID_Doc2k:
286 name="2000";
287 initroutine = symbol_request(DoC2k_init);
288 break;
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;
299 case DOC_ChipID_DocMilPlus16:
300 case DOC_ChipID_DocMilPlus32:
301 name="MillenniumPlus";
302 initroutine = symbol_request(DoCMilPlus_init);
303 break;
306 if (initroutine) {
307 (*initroutine)(mtd);
308 symbol_put_addr(initroutine);
309 return;
311 printk(KERN_NOTICE "Cannot find driver for DiskOnChip %s at 0x%lX\n", name, physadr);
312 kfree(mtd);
314 iounmap(docptr);
318 /****************************************************************************
320 * Module stuff
322 ****************************************************************************/
324 static int __init init_doc(void)
326 int i;
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]);
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;
343 module_init(init_doc);
345 MODULE_LICENSE("GPL");
346 MODULE_AUTHOR("David Woodhouse <dwmw2@infradead.org>");
347 MODULE_DESCRIPTION("Probe code for DiskOnChip 2000 and Millennium devices");