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
24static void print_cfi_ident(struct cfi_ident *);
25#endif
26
27static int cfi_probe_chip(struct map_info *map, __u32 base,
28			  unsigned long *chip_map, struct cfi_private *cfi);
29static int cfi_chip_setup(struct map_info *map, struct cfi_private *cfi);
30
31struct 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) \
39do { \
40	(void) map_read(map, base); \
41	xip_iprefetch(); \
42	local_irq_enable(); \
43} while (0)
44
45#define xip_enable(base, map, cfi) \
46do { \
47	cfi_qry_mode_off(base, map, cfi);		\
48	xip_allowed(base, map); \
49} while (0)
50
51#define xip_disable_qry(base, map, cfi) \
52do { \
53	xip_disable(); \
54	cfi_qry_mode_on(base, map, cfi); \
55} while (0)
56
57#else
58
59#define xip_disable()			do { } while (0)
60#define xip_allowed(base, map)		do { } while (0)
61#define xip_enable(base, map, cfi)	do { } while (0)
62#define xip_disable_qry(base, map, cfi) do { } while (0)
63
64#endif
65
66/* check for QRY.
67   in: interleave,type,mode
68   ret: table index, <0 for error
69 */
70
71static int __xipram cfi_probe_chip(struct map_info *map, __u32 base,
72				   unsigned long *chip_map, struct cfi_private *cfi)
73{
74	int i;
75
76	if ((base + 0) >= map->size) {
77		printk(KERN_NOTICE
78			"Probe at base[0x00](0x%08lx) past the end of the map(0x%08lx)\n",
79			(unsigned long)base, map->size -1);
80		return 0;
81	}
82	if ((base + 0xff) >= map->size) {
83		printk(KERN_NOTICE
84			"Probe at base[0x55](0x%08lx) past the end of the map(0x%08lx)\n",
85			(unsigned long)base + 0x55, map->size -1);
86		return 0;
87	}
88
89	xip_disable();
90	if (!cfi_qry_mode_on(base, map, cfi)) {
91		xip_enable(base, map, cfi);
92		return 0;
93	}
94
95	if (!cfi->numchips) {
96		/* This is the first time we're called. Set up the CFI
97		   stuff accordingly and return */
98		return cfi_chip_setup(map, cfi);
99	}
100
101	/* Check each previous chip to see if it's an alias */
102 	for (i=0; i < (base >> cfi->chipshift); i++) {
103 		unsigned long start;
104 		if(!test_bit(i, chip_map)) {
105			/* Skip location; no valid chip at this address */
106 			continue;
107 		}
108 		start = i << cfi->chipshift;
109		/* This chip should be in read mode if it's one
110		   we've already touched. */
111		if (cfi_qry_present(map, start, cfi)) {
112			/* Eep. This chip also had the QRY marker.
113			 * Is it an alias for the new one? */
114			cfi_qry_mode_off(start, map, cfi);
115
116			/* If the QRY marker goes away, it's an alias */
117			if (!cfi_qry_present(map, start, cfi)) {
118				xip_allowed(base, map);
119				printk(KERN_DEBUG "%s: Found an alias at 0x%x for the chip at 0x%lx\n",
120				       map->name, base, start);
121				return 0;
122			}
123			/* Yes, it's actually got QRY for data. Most
124			 * unfortunate. Stick the new chip in read mode
125			 * too and if it's the same, assume it's an alias. */
126			/* FIXME: Use other modes to do a proper check */
127			cfi_qry_mode_off(base, map, cfi);
128
129			if (cfi_qry_present(map, base, cfi)) {
130				xip_allowed(base, map);
131				printk(KERN_DEBUG "%s: Found an alias at 0x%x for the chip at 0x%lx\n",
132				       map->name, base, start);
133				return 0;
134			}
135		}
136	}
137
138	/* OK, if we got to here, then none of the previous chips appear to
139	   be aliases for the current one. */
140	set_bit((base >> cfi->chipshift), chip_map); /* Update chip map */
141	cfi->numchips++;
142
143	/* Put it back into Read Mode */
144	cfi_qry_mode_off(base, map, cfi);
145	xip_allowed(base, map);
146
147	printk(KERN_INFO "%s: Found %d x%d devices at 0x%x in %d-bit bank\n",
148	       map->name, cfi->interleave, cfi->device_type*8, base,
149	       map->bankwidth*8);
150
151	return 1;
152}
153
154static int __xipram cfi_chip_setup(struct map_info *map,
155				   struct cfi_private *cfi)
156{
157	int ofs_factor = cfi->interleave*cfi->device_type;
158	__u32 base = 0;
159	int num_erase_regions = cfi_read_query(map, base + (0x10 + 28)*ofs_factor);
160	int i;
161	int addr_unlock1 = 0x555, addr_unlock2 = 0x2AA;
162
163	xip_enable(base, map, cfi);
164#ifdef DEBUG_CFI
165	printk("Number of erase regions: %d\n", num_erase_regions);
166#endif
167	if (!num_erase_regions)
168		return 0;
169
170	cfi->cfiq = kmalloc(sizeof(struct cfi_ident) + num_erase_regions * 4, GFP_KERNEL);
171	if (!cfi->cfiq)
172		return 0;
173
174	memset(cfi->cfiq,0,sizeof(struct cfi_ident));
175
176	cfi->cfi_mode = CFI_MODE_CFI;
177
178	cfi->sector_erase_cmd = CMD(0x30);
179
180	/* Read the CFI info structure */
181	xip_disable_qry(base, map, cfi);
182	for (i=0; i<(sizeof(struct cfi_ident) + num_erase_regions * 4); i++)
183		((unsigned char *)cfi->cfiq)[i] = cfi_read_query(map,base + (0x10 + i)*ofs_factor);
184
185	/* Do any necessary byteswapping */
186	cfi->cfiq->P_ID = le16_to_cpu(cfi->cfiq->P_ID);
187
188	cfi->cfiq->P_ADR = le16_to_cpu(cfi->cfiq->P_ADR);
189	cfi->cfiq->A_ID = le16_to_cpu(cfi->cfiq->A_ID);
190	cfi->cfiq->A_ADR = le16_to_cpu(cfi->cfiq->A_ADR);
191	cfi->cfiq->InterfaceDesc = le16_to_cpu(cfi->cfiq->InterfaceDesc);
192	cfi->cfiq->MaxBufWriteSize = le16_to_cpu(cfi->cfiq->MaxBufWriteSize);
193
194#ifdef DEBUG_CFI
195	/* Dump the information therein */
196	print_cfi_ident(cfi->cfiq);
197#endif
198
199	for (i=0; i<cfi->cfiq->NumEraseRegions; i++) {
200		cfi->cfiq->EraseRegionInfo[i] = le32_to_cpu(cfi->cfiq->EraseRegionInfo[i]);
201
202#ifdef DEBUG_CFI
203		printk("  Erase Region #%d: BlockSize 0x%4.4X bytes, %d blocks\n",
204		       i, (cfi->cfiq->EraseRegionInfo[i] >> 8) & ~0xff,
205		       (cfi->cfiq->EraseRegionInfo[i] & 0xffff) + 1);
206#endif
207	}
208
209	if (cfi->cfiq->P_ID == P_ID_SST_OLD) {
210		addr_unlock1 = 0x5555;
211		addr_unlock2 = 0x2AAA;
212	}
213
214	/*
215	 * Note we put the device back into Read Mode BEFORE going into Auto
216	 * Select Mode, as some devices support nesting of modes, others
217	 * don't. This way should always work.
218	 * On cmdset 0001 the writes of 0xaa and 0x55 are not needed, and
219	 * so should be treated as nops or illegal (and so put the device
220	 * back into Read Mode, which is a nop in this case).
221	 */
222	cfi_send_gen_cmd(0xf0,     0, base, map, cfi, cfi->device_type, NULL);
223	cfi_send_gen_cmd(0xaa, addr_unlock1, base, map, cfi, cfi->device_type, NULL);
224	cfi_send_gen_cmd(0x55, addr_unlock2, base, map, cfi, cfi->device_type, NULL);
225	cfi_send_gen_cmd(0x90, addr_unlock1, base, map, cfi, cfi->device_type, NULL);
226	cfi->mfr = cfi_read_query16(map, base);
227	cfi->id = cfi_read_query16(map, base + ofs_factor);
228
229	/* Get AMD/Spansion extended JEDEC ID */
230	if (cfi->mfr == CFI_MFR_AMD && (cfi->id & 0xff) == 0x7e)
231		cfi->id = cfi_read_query(map, base + 0xe * ofs_factor) << 8 |
232			  cfi_read_query(map, base + 0xf * ofs_factor);
233
234	/* Put it back into Read Mode */
235	cfi_qry_mode_off(base, map, cfi);
236	xip_allowed(base, map);
237
238	printk(KERN_INFO "%s: Found %d x%d devices at 0x%x in %d-bit bank. Manufacturer ID %#08x Chip ID %#08x\n",
239	       map->name, cfi->interleave, cfi->device_type*8, base,
240	       map->bankwidth*8, cfi->mfr, cfi->id);
241
242	return 1;
243}
244
245#ifdef DEBUG_CFI
246static char *vendorname(__u16 vendor)
247{
248	switch (vendor) {
249	case P_ID_NONE:
250		return "None";
251
252	case P_ID_INTEL_EXT:
253		return "Intel/Sharp Extended";
254
255	case P_ID_AMD_STD:
256		return "AMD/Fujitsu Standard";
257
258	case P_ID_INTEL_STD:
259		return "Intel/Sharp Standard";
260
261	case P_ID_AMD_EXT:
262		return "AMD/Fujitsu Extended";
263
264	case P_ID_WINBOND:
265		return "Winbond Standard";
266
267	case P_ID_ST_ADV:
268		return "ST Advanced";
269
270	case P_ID_MITSUBISHI_STD:
271		return "Mitsubishi Standard";
272
273	case P_ID_MITSUBISHI_EXT:
274		return "Mitsubishi Extended";
275
276	case P_ID_SST_PAGE:
277		return "SST Page Write";
278
279	case P_ID_SST_OLD:
280		return "SST 39VF160x/39VF320x";
281
282	case P_ID_INTEL_PERFORMANCE:
283		return "Intel Performance Code";
284
285	case P_ID_INTEL_DATA:
286		return "Intel Data";
287
288	case P_ID_RESERVED:
289		return "Not Allowed / Reserved for Future Use";
290
291	default:
292		return "Unknown";
293	}
294}
295
296
297static void print_cfi_ident(struct cfi_ident *cfip)
298{
299#if 0
300	if (cfip->qry[0] != 'Q' || cfip->qry[1] != 'R' || cfip->qry[2] != 'Y') {
301		printk("Invalid CFI ident structure.\n");
302		return;
303	}
304#endif
305	printk("Primary Vendor Command Set: %4.4X (%s)\n", cfip->P_ID, vendorname(cfip->P_ID));
306	if (cfip->P_ADR)
307		printk("Primary Algorithm Table at %4.4X\n", cfip->P_ADR);
308	else
309		printk("No Primary Algorithm Table\n");
310
311	printk("Alternative Vendor Command Set: %4.4X (%s)\n", cfip->A_ID, vendorname(cfip->A_ID));
312	if (cfip->A_ADR)
313		printk("Alternate Algorithm Table at %4.4X\n", cfip->A_ADR);
314	else
315		printk("No Alternate Algorithm Table\n");
316
317
318	printk("Vcc Minimum: %2d.%d V\n", cfip->VccMin >> 4, cfip->VccMin & 0xf);
319	printk("Vcc Maximum: %2d.%d V\n", cfip->VccMax >> 4, cfip->VccMax & 0xf);
320	if (cfip->VppMin) {
321		printk("Vpp Minimum: %2d.%d V\n", cfip->VppMin >> 4, cfip->VppMin & 0xf);
322		printk("Vpp Maximum: %2d.%d V\n", cfip->VppMax >> 4, cfip->VppMax & 0xf);
323	}
324	else
325		printk("No Vpp line\n");
326
327	printk("Typical byte/word write timeout: %d µs\n", 1<<cfip->WordWriteTimeoutTyp);
328	printk("Maximum byte/word write timeout: %d µs\n", (1<<cfip->WordWriteTimeoutMax) * (1<<cfip->WordWriteTimeoutTyp));
329
330	if (cfip->BufWriteTimeoutTyp || cfip->BufWriteTimeoutMax) {
331		printk("Typical full buffer write timeout: %d µs\n", 1<<cfip->BufWriteTimeoutTyp);
332		printk("Maximum full buffer write timeout: %d µs\n", (1<<cfip->BufWriteTimeoutMax) * (1<<cfip->BufWriteTimeoutTyp));
333	}
334	else
335		printk("Full buffer write not supported\n");
336
337	printk("Typical block erase timeout: %d ms\n", 1<<cfip->BlockEraseTimeoutTyp);
338	printk("Maximum block erase timeout: %d ms\n", (1<<cfip->BlockEraseTimeoutMax) * (1<<cfip->BlockEraseTimeoutTyp));
339	if (cfip->ChipEraseTimeoutTyp || cfip->ChipEraseTimeoutMax) {
340		printk("Typical chip erase timeout: %d ms\n", 1<<cfip->ChipEraseTimeoutTyp);
341		printk("Maximum chip erase timeout: %d ms\n", (1<<cfip->ChipEraseTimeoutMax) * (1<<cfip->ChipEraseTimeoutTyp));
342	}
343	else
344		printk("Chip erase not supported\n");
345
346	printk("Device size: 0x%X bytes (%d MiB)\n", 1 << cfip->DevSize, 1<< (cfip->DevSize - 20));
347	printk("Flash Device Interface description: 0x%4.4X\n", cfip->InterfaceDesc);
348	switch(cfip->InterfaceDesc) {
349	case CFI_INTERFACE_X8_ASYNC:
350		printk("  - x8-only asynchronous interface\n");
351		break;
352
353	case CFI_INTERFACE_X16_ASYNC:
354		printk("  - x16-only asynchronous interface\n");
355		break;
356
357	case CFI_INTERFACE_X8_BY_X16_ASYNC:
358		printk("  - supports x8 and x16 via BYTE# with asynchronous interface\n");
359		break;
360
361	case CFI_INTERFACE_X32_ASYNC:
362		printk("  - x32-only asynchronous interface\n");
363		break;
364
365	case CFI_INTERFACE_X16_BY_X32_ASYNC:
366		printk("  - supports x16 and x32 via Word# with asynchronous interface\n");
367		break;
368
369	case CFI_INTERFACE_NOT_ALLOWED:
370		printk("  - Not Allowed / Reserved\n");
371		break;
372
373	default:
374		printk("  - Unknown\n");
375		break;
376	}
377
378	printk("Max. bytes in buffer write: 0x%x\n", 1<< cfip->MaxBufWriteSize);
379	printk("Number of Erase Block Regions: %d\n", cfip->NumEraseRegions);
380
381}
382#endif /* DEBUG_CFI */
383
384static struct chip_probe cfi_chip_probe = {
385	.name		= "CFI",
386	.probe_chip	= cfi_probe_chip
387};
388
389struct mtd_info *cfi_probe(struct map_info *map)
390{
391	/*
392	 * Just use the generic probe stuff to call our CFI-specific
393	 * chip_probe routine in all the possible permutations, etc.
394	 */
395	return mtd_do_chip_probe(map, &cfi_chip_probe);
396}
397
398static struct mtd_chip_driver cfi_chipdrv = {
399	.probe		= cfi_probe,
400	.name		= "cfi_probe",
401	.module		= THIS_MODULE
402};
403
404static int __init cfi_probe_init(void)
405{
406	register_mtd_chip_driver(&cfi_chipdrv);
407	return 0;
408}
409
410static void __exit cfi_probe_exit(void)
411{
412	unregister_mtd_chip_driver(&cfi_chipdrv);
413}
414
415module_init(cfi_probe_init);
416module_exit(cfi_probe_exit);
417
418MODULE_LICENSE("GPL");
419MODULE_AUTHOR("David Woodhouse <dwmw2@infradead.org> et al.");
420MODULE_DESCRIPTION("Probe code for CFI-compliant flash chips");
421