xref: /openbmc/linux/drivers/mtd/chips/cfi_probe.c (revision 384740dc)
1 /*
2    Common Flash Interface probe code.
3    (C) 2000 Red Hat. GPL'd.
4 */
5 
6 #include <linux/module.h>
7 #include <linux/types.h>
8 #include <linux/kernel.h>
9 #include <linux/init.h>
10 #include <asm/io.h>
11 #include <asm/byteorder.h>
12 #include <linux/errno.h>
13 #include <linux/slab.h>
14 #include <linux/interrupt.h>
15 
16 #include <linux/mtd/xip.h>
17 #include <linux/mtd/map.h>
18 #include <linux/mtd/cfi.h>
19 #include <linux/mtd/gen_probe.h>
20 
21 //#define DEBUG_CFI
22 
23 #ifdef DEBUG_CFI
24 static void print_cfi_ident(struct cfi_ident *);
25 #endif
26 
27 static int cfi_probe_chip(struct map_info *map, __u32 base,
28 			  unsigned long *chip_map, struct cfi_private *cfi);
29 static int cfi_chip_setup(struct map_info *map, struct cfi_private *cfi);
30 
31 struct mtd_info *cfi_probe(struct map_info *map);
32 
33 #ifdef CONFIG_MTD_XIP
34 
35 /* only needed for short periods, so this is rather simple */
36 #define xip_disable()	local_irq_disable()
37 
38 #define xip_allowed(base, map) \
39 do { \
40 	(void) map_read(map, base); \
41 	xip_iprefetch(); \
42 	local_irq_enable(); \
43 } while (0)
44 
45 #define xip_enable(base, map, cfi) \
46 do { \
47 	cfi_send_gen_cmd(0xF0, 0, base, map, cfi, cfi->device_type, NULL); \
48 	cfi_send_gen_cmd(0xFF, 0, base, map, cfi, cfi->device_type, NULL); \
49 	xip_allowed(base, map); \
50 } while (0)
51 
52 #define xip_disable_qry(base, map, cfi) \
53 do { \
54 	xip_disable(); \
55 	cfi_send_gen_cmd(0xF0, 0, base, map, cfi, cfi->device_type, NULL); \
56 	cfi_send_gen_cmd(0xFF, 0, base, map, cfi, cfi->device_type, NULL); \
57 	cfi_send_gen_cmd(0x98, 0x55, base, map, cfi, cfi->device_type, NULL); \
58 } while (0)
59 
60 #else
61 
62 #define xip_disable()			do { } while (0)
63 #define xip_allowed(base, map)		do { } while (0)
64 #define xip_enable(base, map, cfi)	do { } while (0)
65 #define xip_disable_qry(base, map, cfi) do { } while (0)
66 
67 #endif
68 
69 /* check for QRY.
70    in: interleave,type,mode
71    ret: table index, <0 for error
72  */
73 static int __xipram qry_present(struct map_info *map, __u32 base,
74 				struct cfi_private *cfi)
75 {
76 	int osf = cfi->interleave * cfi->device_type;	// scale factor
77 	map_word val[3];
78 	map_word qry[3];
79 
80 	qry[0] = cfi_build_cmd('Q', map, cfi);
81 	qry[1] = cfi_build_cmd('R', map, cfi);
82 	qry[2] = cfi_build_cmd('Y', map, cfi);
83 
84 	val[0] = map_read(map, base + osf*0x10);
85 	val[1] = map_read(map, base + osf*0x11);
86 	val[2] = map_read(map, base + osf*0x12);
87 
88 	if (!map_word_equal(map, qry[0], val[0]))
89 		return 0;
90 
91 	if (!map_word_equal(map, qry[1], val[1]))
92 		return 0;
93 
94 	if (!map_word_equal(map, qry[2], val[2]))
95 		return 0;
96 
97 	return 1; 	// "QRY" found
98 }
99 
100 static int __xipram cfi_probe_chip(struct map_info *map, __u32 base,
101 				   unsigned long *chip_map, struct cfi_private *cfi)
102 {
103 	int i;
104 
105 	if ((base + 0) >= map->size) {
106 		printk(KERN_NOTICE
107 			"Probe at base[0x00](0x%08lx) past the end of the map(0x%08lx)\n",
108 			(unsigned long)base, map->size -1);
109 		return 0;
110 	}
111 	if ((base + 0xff) >= map->size) {
112 		printk(KERN_NOTICE
113 			"Probe at base[0x55](0x%08lx) past the end of the map(0x%08lx)\n",
114 			(unsigned long)base + 0x55, map->size -1);
115 		return 0;
116 	}
117 
118 	xip_disable();
119 	cfi_send_gen_cmd(0xF0, 0, base, map, cfi, cfi->device_type, NULL);
120 	cfi_send_gen_cmd(0xFF, 0, base, map, cfi, cfi->device_type, NULL);
121 	cfi_send_gen_cmd(0x98, 0x55, base, map, cfi, cfi->device_type, NULL);
122 
123 	if (!qry_present(map,base,cfi)) {
124 		xip_enable(base, map, cfi);
125 		return 0;
126 	}
127 
128 	if (!cfi->numchips) {
129 		/* This is the first time we're called. Set up the CFI
130 		   stuff accordingly and return */
131 		return cfi_chip_setup(map, cfi);
132 	}
133 
134 	/* Check each previous chip to see if it's an alias */
135  	for (i=0; i < (base >> cfi->chipshift); i++) {
136  		unsigned long start;
137  		if(!test_bit(i, chip_map)) {
138 			/* Skip location; no valid chip at this address */
139  			continue;
140  		}
141  		start = i << cfi->chipshift;
142 		/* This chip should be in read mode if it's one
143 		   we've already touched. */
144 		if (qry_present(map, start, cfi)) {
145 			/* Eep. This chip also had the QRY marker.
146 			 * Is it an alias for the new one? */
147 			cfi_send_gen_cmd(0xF0, 0, start, map, cfi, cfi->device_type, NULL);
148 			cfi_send_gen_cmd(0xFF, 0, start, map, cfi, cfi->device_type, NULL);
149 
150 			/* If the QRY marker goes away, it's an alias */
151 			if (!qry_present(map, start, cfi)) {
152 				xip_allowed(base, map);
153 				printk(KERN_DEBUG "%s: Found an alias at 0x%x for the chip at 0x%lx\n",
154 				       map->name, base, start);
155 				return 0;
156 			}
157 			/* Yes, it's actually got QRY for data. Most
158 			 * unfortunate. Stick the new chip in read mode
159 			 * too and if it's the same, assume it's an alias. */
160 			/* FIXME: Use other modes to do a proper check */
161 			cfi_send_gen_cmd(0xF0, 0, base, map, cfi, cfi->device_type, NULL);
162 			cfi_send_gen_cmd(0xFF, 0, start, map, cfi, cfi->device_type, NULL);
163 
164 			if (qry_present(map, base, cfi)) {
165 				xip_allowed(base, map);
166 				printk(KERN_DEBUG "%s: Found an alias at 0x%x for the chip at 0x%lx\n",
167 				       map->name, base, start);
168 				return 0;
169 			}
170 		}
171 	}
172 
173 	/* OK, if we got to here, then none of the previous chips appear to
174 	   be aliases for the current one. */
175 	set_bit((base >> cfi->chipshift), chip_map); /* Update chip map */
176 	cfi->numchips++;
177 
178 	/* Put it back into Read Mode */
179 	cfi_send_gen_cmd(0xF0, 0, base, map, cfi, cfi->device_type, NULL);
180 	cfi_send_gen_cmd(0xFF, 0, base, map, cfi, cfi->device_type, NULL);
181 	xip_allowed(base, map);
182 
183 	printk(KERN_INFO "%s: Found %d x%d devices at 0x%x in %d-bit bank\n",
184 	       map->name, cfi->interleave, cfi->device_type*8, base,
185 	       map->bankwidth*8);
186 
187 	return 1;
188 }
189 
190 static int __xipram cfi_chip_setup(struct map_info *map,
191 				   struct cfi_private *cfi)
192 {
193 	int ofs_factor = cfi->interleave*cfi->device_type;
194 	__u32 base = 0;
195 	int num_erase_regions = cfi_read_query(map, base + (0x10 + 28)*ofs_factor);
196 	int i;
197 
198 	xip_enable(base, map, cfi);
199 #ifdef DEBUG_CFI
200 	printk("Number of erase regions: %d\n", num_erase_regions);
201 #endif
202 	if (!num_erase_regions)
203 		return 0;
204 
205 	cfi->cfiq = kmalloc(sizeof(struct cfi_ident) + num_erase_regions * 4, GFP_KERNEL);
206 	if (!cfi->cfiq) {
207 		printk(KERN_WARNING "%s: kmalloc failed for CFI ident structure\n", map->name);
208 		return 0;
209 	}
210 
211 	memset(cfi->cfiq,0,sizeof(struct cfi_ident));
212 
213 	cfi->cfi_mode = CFI_MODE_CFI;
214 
215 	/* Read the CFI info structure */
216 	xip_disable_qry(base, map, cfi);
217 	for (i=0; i<(sizeof(struct cfi_ident) + num_erase_regions * 4); i++)
218 		((unsigned char *)cfi->cfiq)[i] = cfi_read_query(map,base + (0x10 + i)*ofs_factor);
219 
220 	/* Note we put the device back into Read Mode BEFORE going into Auto
221 	 * Select Mode, as some devices support nesting of modes, others
222 	 * don't. This way should always work.
223 	 * On cmdset 0001 the writes of 0xaa and 0x55 are not needed, and
224 	 * so should be treated as nops or illegal (and so put the device
225 	 * back into Read Mode, which is a nop in this case).
226 	 */
227 	cfi_send_gen_cmd(0xf0,     0, base, map, cfi, cfi->device_type, NULL);
228 	cfi_send_gen_cmd(0xaa, 0x555, base, map, cfi, cfi->device_type, NULL);
229 	cfi_send_gen_cmd(0x55, 0x2aa, base, map, cfi, cfi->device_type, NULL);
230 	cfi_send_gen_cmd(0x90, 0x555, base, map, cfi, cfi->device_type, NULL);
231 	cfi->mfr = cfi_read_query16(map, base);
232 	cfi->id = cfi_read_query16(map, base + ofs_factor);
233 
234 	/* Get AMD/Spansion extended JEDEC ID */
235 	if (cfi->mfr == CFI_MFR_AMD && (cfi->id & 0xff) == 0x7e)
236 		cfi->id = cfi_read_query(map, base + 0xe * ofs_factor) << 8 |
237 			  cfi_read_query(map, base + 0xf * ofs_factor);
238 
239 	/* Put it back into Read Mode */
240 	cfi_send_gen_cmd(0xF0, 0, base, map, cfi, cfi->device_type, NULL);
241 	/* ... even if it's an Intel chip */
242 	cfi_send_gen_cmd(0xFF, 0, base, map, cfi, cfi->device_type, NULL);
243 	xip_allowed(base, map);
244 
245 	/* Do any necessary byteswapping */
246 	cfi->cfiq->P_ID = le16_to_cpu(cfi->cfiq->P_ID);
247 
248 	cfi->cfiq->P_ADR = le16_to_cpu(cfi->cfiq->P_ADR);
249 	cfi->cfiq->A_ID = le16_to_cpu(cfi->cfiq->A_ID);
250 	cfi->cfiq->A_ADR = le16_to_cpu(cfi->cfiq->A_ADR);
251 	cfi->cfiq->InterfaceDesc = le16_to_cpu(cfi->cfiq->InterfaceDesc);
252 	cfi->cfiq->MaxBufWriteSize = le16_to_cpu(cfi->cfiq->MaxBufWriteSize);
253 
254 #ifdef DEBUG_CFI
255 	/* Dump the information therein */
256 	print_cfi_ident(cfi->cfiq);
257 #endif
258 
259 	for (i=0; i<cfi->cfiq->NumEraseRegions; i++) {
260 		cfi->cfiq->EraseRegionInfo[i] = le32_to_cpu(cfi->cfiq->EraseRegionInfo[i]);
261 
262 #ifdef DEBUG_CFI
263 		printk("  Erase Region #%d: BlockSize 0x%4.4X bytes, %d blocks\n",
264 		       i, (cfi->cfiq->EraseRegionInfo[i] >> 8) & ~0xff,
265 		       (cfi->cfiq->EraseRegionInfo[i] & 0xffff) + 1);
266 #endif
267 	}
268 
269 	printk(KERN_INFO "%s: Found %d x%d devices at 0x%x in %d-bit bank\n",
270 	       map->name, cfi->interleave, cfi->device_type*8, base,
271 	       map->bankwidth*8);
272 
273 	return 1;
274 }
275 
276 #ifdef DEBUG_CFI
277 static char *vendorname(__u16 vendor)
278 {
279 	switch (vendor) {
280 	case P_ID_NONE:
281 		return "None";
282 
283 	case P_ID_INTEL_EXT:
284 		return "Intel/Sharp Extended";
285 
286 	case P_ID_AMD_STD:
287 		return "AMD/Fujitsu Standard";
288 
289 	case P_ID_INTEL_STD:
290 		return "Intel/Sharp Standard";
291 
292 	case P_ID_AMD_EXT:
293 		return "AMD/Fujitsu Extended";
294 
295 	case P_ID_WINBOND:
296 		return "Winbond Standard";
297 
298 	case P_ID_ST_ADV:
299 		return "ST Advanced";
300 
301 	case P_ID_MITSUBISHI_STD:
302 		return "Mitsubishi Standard";
303 
304 	case P_ID_MITSUBISHI_EXT:
305 		return "Mitsubishi Extended";
306 
307 	case P_ID_SST_PAGE:
308 		return "SST Page Write";
309 
310 	case P_ID_INTEL_PERFORMANCE:
311 		return "Intel Performance Code";
312 
313 	case P_ID_INTEL_DATA:
314 		return "Intel Data";
315 
316 	case P_ID_RESERVED:
317 		return "Not Allowed / Reserved for Future Use";
318 
319 	default:
320 		return "Unknown";
321 	}
322 }
323 
324 
325 static void print_cfi_ident(struct cfi_ident *cfip)
326 {
327 #if 0
328 	if (cfip->qry[0] != 'Q' || cfip->qry[1] != 'R' || cfip->qry[2] != 'Y') {
329 		printk("Invalid CFI ident structure.\n");
330 		return;
331 	}
332 #endif
333 	printk("Primary Vendor Command Set: %4.4X (%s)\n", cfip->P_ID, vendorname(cfip->P_ID));
334 	if (cfip->P_ADR)
335 		printk("Primary Algorithm Table at %4.4X\n", cfip->P_ADR);
336 	else
337 		printk("No Primary Algorithm Table\n");
338 
339 	printk("Alternative Vendor Command Set: %4.4X (%s)\n", cfip->A_ID, vendorname(cfip->A_ID));
340 	if (cfip->A_ADR)
341 		printk("Alternate Algorithm Table at %4.4X\n", cfip->A_ADR);
342 	else
343 		printk("No Alternate Algorithm Table\n");
344 
345 
346 	printk("Vcc Minimum: %2d.%d V\n", cfip->VccMin >> 4, cfip->VccMin & 0xf);
347 	printk("Vcc Maximum: %2d.%d V\n", cfip->VccMax >> 4, cfip->VccMax & 0xf);
348 	if (cfip->VppMin) {
349 		printk("Vpp Minimum: %2d.%d V\n", cfip->VppMin >> 4, cfip->VppMin & 0xf);
350 		printk("Vpp Maximum: %2d.%d V\n", cfip->VppMax >> 4, cfip->VppMax & 0xf);
351 	}
352 	else
353 		printk("No Vpp line\n");
354 
355 	printk("Typical byte/word write timeout: %d µs\n", 1<<cfip->WordWriteTimeoutTyp);
356 	printk("Maximum byte/word write timeout: %d µs\n", (1<<cfip->WordWriteTimeoutMax) * (1<<cfip->WordWriteTimeoutTyp));
357 
358 	if (cfip->BufWriteTimeoutTyp || cfip->BufWriteTimeoutMax) {
359 		printk("Typical full buffer write timeout: %d µs\n", 1<<cfip->BufWriteTimeoutTyp);
360 		printk("Maximum full buffer write timeout: %d µs\n", (1<<cfip->BufWriteTimeoutMax) * (1<<cfip->BufWriteTimeoutTyp));
361 	}
362 	else
363 		printk("Full buffer write not supported\n");
364 
365 	printk("Typical block erase timeout: %d ms\n", 1<<cfip->BlockEraseTimeoutTyp);
366 	printk("Maximum block erase timeout: %d ms\n", (1<<cfip->BlockEraseTimeoutMax) * (1<<cfip->BlockEraseTimeoutTyp));
367 	if (cfip->ChipEraseTimeoutTyp || cfip->ChipEraseTimeoutMax) {
368 		printk("Typical chip erase timeout: %d ms\n", 1<<cfip->ChipEraseTimeoutTyp);
369 		printk("Maximum chip erase timeout: %d ms\n", (1<<cfip->ChipEraseTimeoutMax) * (1<<cfip->ChipEraseTimeoutTyp));
370 	}
371 	else
372 		printk("Chip erase not supported\n");
373 
374 	printk("Device size: 0x%X bytes (%d MiB)\n", 1 << cfip->DevSize, 1<< (cfip->DevSize - 20));
375 	printk("Flash Device Interface description: 0x%4.4X\n", cfip->InterfaceDesc);
376 	switch(cfip->InterfaceDesc) {
377 	case CFI_INTERFACE_X8_ASYNC:
378 		printk("  - x8-only asynchronous interface\n");
379 		break;
380 
381 	case CFI_INTERFACE_X16_ASYNC:
382 		printk("  - x16-only asynchronous interface\n");
383 		break;
384 
385 	case CFI_INTERFACE_X8_BY_X16_ASYNC:
386 		printk("  - supports x8 and x16 via BYTE# with asynchronous interface\n");
387 		break;
388 
389 	case CFI_INTERFACE_X32_ASYNC:
390 		printk("  - x32-only asynchronous interface\n");
391 		break;
392 
393 	case CFI_INTERFACE_X16_BY_X32_ASYNC:
394 		printk("  - supports x16 and x32 via Word# with asynchronous interface\n");
395 		break;
396 
397 	case CFI_INTERFACE_NOT_ALLOWED:
398 		printk("  - Not Allowed / Reserved\n");
399 		break;
400 
401 	default:
402 		printk("  - Unknown\n");
403 		break;
404 	}
405 
406 	printk("Max. bytes in buffer write: 0x%x\n", 1<< cfip->MaxBufWriteSize);
407 	printk("Number of Erase Block Regions: %d\n", cfip->NumEraseRegions);
408 
409 }
410 #endif /* DEBUG_CFI */
411 
412 static struct chip_probe cfi_chip_probe = {
413 	.name		= "CFI",
414 	.probe_chip	= cfi_probe_chip
415 };
416 
417 struct mtd_info *cfi_probe(struct map_info *map)
418 {
419 	/*
420 	 * Just use the generic probe stuff to call our CFI-specific
421 	 * chip_probe routine in all the possible permutations, etc.
422 	 */
423 	return mtd_do_chip_probe(map, &cfi_chip_probe);
424 }
425 
426 static struct mtd_chip_driver cfi_chipdrv = {
427 	.probe		= cfi_probe,
428 	.name		= "cfi_probe",
429 	.module		= THIS_MODULE
430 };
431 
432 static int __init cfi_probe_init(void)
433 {
434 	register_mtd_chip_driver(&cfi_chipdrv);
435 	return 0;
436 }
437 
438 static void __exit cfi_probe_exit(void)
439 {
440 	unregister_mtd_chip_driver(&cfi_chipdrv);
441 }
442 
443 module_init(cfi_probe_init);
444 module_exit(cfi_probe_exit);
445 
446 MODULE_LICENSE("GPL");
447 MODULE_AUTHOR("David Woodhouse <dwmw2@infradead.org> et al.");
448 MODULE_DESCRIPTION("Probe code for CFI-compliant flash chips");
449