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 1.36 2003/05/23 11:29:34 dwmw2 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_PARM(doc_config_location, "l");
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(unsigned long potential, unsigned long physadr)
99 unsigned long 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 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 the TOGGLE bit in the ECC register */
152 tmp = ReadDOC(window, ECCConf) & DOC_TOGGLE_BIT;
153 tmpb = ReadDOC(window, ECCConf) & DOC_TOGGLE_BIT;
154 tmpc = ReadDOC(window, ECCConf) & DOC_TOGGLE_BIT;
155 if (tmp != tmpb && tmp == tmpc)
159 case DOC_ChipID_DocMilPlus16:
160 case DOC_ChipID_DocMilPlus32:
162 /* Possible Millennium+, need to do more checks */
163 #ifndef DOC_PASSIVE_PROBE
164 /* Possibly release from power down mode */
165 for (tmp = 0; (tmp < 4); tmp++)
166 ReadDOC(window, Mplus_Power);
168 /* Reset the DiskOnChip ASIC */
169 tmp = DOC_MODE_RESET | DOC_MODE_MDWREN | DOC_MODE_RST_LAT |
171 WriteDOC(tmp, window, Mplus_DOCControl);
172 WriteDOC(~tmp, window, Mplus_CtrlConfirm);
175 /* Enable the DiskOnChip ASIC */
176 tmp = DOC_MODE_NORMAL | DOC_MODE_MDWREN | DOC_MODE_RST_LAT |
178 WriteDOC(tmp, window, Mplus_DOCControl);
179 WriteDOC(~tmp, window, Mplus_CtrlConfirm);
181 #endif /* !DOC_PASSIVE_PROBE */
183 ChipID = ReadDOC(window, ChipID);
186 case DOC_ChipID_DocMilPlus16:
187 case DOC_ChipID_DocMilPlus32:
188 /* Check the TOGGLE bit in the toggle register */
189 tmp = ReadDOC(window, Mplus_Toggle) & DOC_TOGGLE_BIT;
190 tmpb = ReadDOC(window, Mplus_Toggle) & DOC_TOGGLE_BIT;
191 tmpc = ReadDOC(window, Mplus_Toggle) & DOC_TOGGLE_BIT;
192 if (tmp != tmpb && tmp == tmpc)
202 #ifndef CONFIG_MTD_DOCPROBE_55AA
203 printk(KERN_WARNING "Possible DiskOnChip with unknown ChipID %2.2X found at 0x%lx\n",
206 #ifndef DOC_PASSIVE_PROBE
207 /* Put back the contents of the DOCControl register, in case it's not
208 * actually a DiskOnChip.
210 WriteDOC(tmp2, window, DOCControl);
215 printk(KERN_WARNING "DiskOnChip failed TOGGLE test, dropping.\n");
217 #ifndef DOC_PASSIVE_PROBE
218 /* Put back the contents of the DOCControl register: it's not a DiskOnChip */
219 WriteDOC(tmp2, window, DOCControl);
226 static void __init DoC_Probe(unsigned long physadr)
228 unsigned long docptr;
229 struct DiskOnChip *this;
230 struct mtd_info *mtd;
233 char *name = namebuf;
234 char *im_funcname = NULL;
235 char *im_modname = NULL;
236 void (*initroutine)(struct mtd_info *) = NULL;
238 docptr = (unsigned long)ioremap(physadr, DOC_IOREMAP_LEN);
243 if ((ChipID = doccheck(docptr, physadr))) {
245 mtd = kmalloc(sizeof(struct DiskOnChip) + sizeof(struct mtd_info), GFP_KERNEL);
248 printk(KERN_WARNING "Cannot allocate memory for data structures. Dropping.\n");
249 iounmap((void *)docptr);
253 this = (struct DiskOnChip *)(&mtd[1]);
255 memset((char *)mtd,0, sizeof(struct mtd_info));
256 memset((char *)this, 0, sizeof(struct DiskOnChip));
259 this->virtadr = docptr;
260 this->physadr = physadr;
261 this->ChipID = ChipID;
262 sprintf(namebuf, "with ChipID %2.2X", ChipID);
265 case DOC_ChipID_Doc2k:
267 im_funcname = "DoC2k_init";
268 im_modname = "doc2000";
271 case DOC_ChipID_DocMil:
273 #ifdef DOC_SINGLE_DRIVER
274 im_funcname = "DoC2k_init";
275 im_modname = "doc2000";
277 im_funcname = "DoCMil_init";
278 im_modname = "doc2001";
279 #endif /* DOC_SINGLE_DRIVER */
282 case DOC_ChipID_DocMilPlus16:
283 case DOC_ChipID_DocMilPlus32:
284 name="MillenniumPlus";
285 im_funcname = "DoCMilPlus_init";
286 im_modname = "doc2001plus";
291 initroutine = inter_module_get_request(im_funcname, im_modname);
295 inter_module_put(im_funcname);
298 printk(KERN_NOTICE "Cannot find driver for DiskOnChip %s at 0x%lX\n", name, physadr);
301 iounmap((void *)docptr);
305 /****************************************************************************
309 ****************************************************************************/
311 int __init init_doc(void)
315 if (doc_config_location) {
316 printk(KERN_INFO "Using configured DiskOnChip probe address 0x%lx\n", doc_config_location);
317 DoC_Probe(doc_config_location);
319 for (i=0; (doc_locations[i] != 0xffffffff); i++) {
320 DoC_Probe(doc_locations[i]);
323 /* No banner message any more. Print a message if no DiskOnChip
324 found, so the user knows we at least tried. */
326 printk(KERN_INFO "No recognised DiskOnChip devices found\n");
330 module_init(init_doc);
332 MODULE_LICENSE("GPL");
333 MODULE_AUTHOR("David Woodhouse <dwmw2@infradead.org>");
334 MODULE_DESCRIPTION("Probe code for DiskOnChip 2000 and Millennium devices");