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		printk(KERN_WARNING "%s: kmalloc failed for CFI ident structure\n", map->name);
173		return 0;
174	}
175
176	memset(cfi->cfiq,0,sizeof(struct cfi_ident));
177
178	cfi->cfi_mode = CFI_MODE_CFI;
179
180	cfi->sector_erase_cmd = CMD(0x30);
181
182	/* Read the CFI info structure */
183	xip_disable_qry(base, map, cfi);
184	for (i=0; i<(sizeof(struct cfi_ident) + num_erase_regions * 4); i++)
185		((unsigned char *)cfi->cfiq)[i] = cfi_read_query(map,base + (0x10 + i)*ofs_factor);
186
187	/* Do any necessary byteswapping */
188	cfi->cfiq->P_ID = le16_to_cpu(cfi->cfiq->P_ID);
189
190	cfi->cfiq->P_ADR = le16_to_cpu(cfi->cfiq->P_ADR);
191	cfi->cfiq->A_ID = le16_to_cpu(cfi->cfiq->A_ID);
192	cfi->cfiq->A_ADR = le16_to_cpu(cfi->cfiq->A_ADR);
193	cfi->cfiq->InterfaceDesc = le16_to_cpu(cfi->cfiq->InterfaceDesc);
194	cfi->cfiq->MaxBufWriteSize = le16_to_cpu(cfi->cfiq->MaxBufWriteSize);
195
196#ifdef DEBUG_CFI
197	/* Dump the information therein */
198	print_cfi_ident(cfi->cfiq);
199#endif
200
201	for (i=0; i<cfi->cfiq->NumEraseRegions; i++) {
202		cfi->cfiq->EraseRegionInfo[i] = le32_to_cpu(cfi->cfiq->EraseRegionInfo[i]);
203
204#ifdef DEBUG_CFI
205		printk("  Erase Region #%d: BlockSize 0x%4.4X bytes, %d blocks\n",
206		       i, (cfi->cfiq->EraseRegionInfo[i] >> 8) & ~0xff,
207		       (cfi->cfiq->EraseRegionInfo[i] & 0xffff) + 1);
208#endif
209	}
210
211	if (cfi->cfiq->P_ID == P_ID_SST_OLD) {
212		addr_unlock1 = 0x5555;
213		addr_unlock2 = 0x2AAA;
214	}
215
216	/*
217	 * Note we put the device back into Read Mode BEFORE going into Auto
218	 * Select Mode, as some devices support nesting of modes, others
219	 * don't. This way should always work.
220	 * On cmdset 0001 the writes of 0xaa and 0x55 are not needed, and
221	 * so should be treated as nops or illegal (and so put the device
222	 * back into Read Mode, which is a nop in this case).
223	 */
224	cfi_send_gen_cmd(0xf0,     0, base, map, cfi, cfi->device_type, NULL);
225	cfi_send_gen_cmd(0xaa, addr_unlock1, base, map, cfi, cfi->device_type, NULL);
226	cfi_send_gen_cmd(0x55, addr_unlock2, base, map, cfi, cfi->device_type, NULL);
227	cfi_send_gen_cmd(0x90, addr_unlock1, base, map, cfi, cfi->device_type, NULL);
228	cfi->mfr = cfi_read_query16(map, base);
229	cfi->id = cfi_read_query16(map, base + ofs_factor);
230
231	/* Get AMD/Spansion extended JEDEC ID */
232	if (cfi->mfr == CFI_MFR_AMD && (cfi->id & 0xff) == 0x7e)
233		cfi->id = cfi_read_query(map, base + 0xe * ofs_factor) << 8 |
234			  cfi_read_query(map, base + 0xf * ofs_factor);
235
236	/* Put it back into Read Mode */
237	cfi_qry_mode_off(base, map, cfi);
238	xip_allowed(base, map);
239
240	printk(KERN_INFO "%s: Found %d x%d devices at 0x%x in %d-bit bank. Manufacturer ID %#08x Chip ID %#08x\n",
241	       map->name, cfi->interleave, cfi->device_type*8, base,
242	       map->bankwidth*8, cfi->mfr, cfi->id);
243
244	return 1;
245}
246
247#ifdef DEBUG_CFI
248static char *vendorname(__u16 vendor)
249{
250	switch (vendor) {
251	case P_ID_NONE:
252		return "None";
253
254	case P_ID_INTEL_EXT:
255		return "Intel/Sharp Extended";
256
257	case P_ID_AMD_STD:
258		return "AMD/Fujitsu Standard";
259
260	case P_ID_INTEL_STD:
261		return "Intel/Sharp Standard";
262
263	case P_ID_AMD_EXT:
264		return "AMD/Fujitsu Extended";
265
266	case P_ID_WINBOND:
267		return "Winbond Standard";
268
269	case P_ID_ST_ADV:
270		return "ST Advanced";
271
272	case P_ID_MITSUBISHI_STD:
273		return "Mitsubishi Standard";
274
275	case P_ID_MITSUBISHI_EXT:
276		return "Mitsubishi Extended";
277
278	case P_ID_SST_PAGE:
279		return "SST Page Write";
280
281	case P_ID_SST_OLD:
282		return "SST 39VF160x/39VF320x";
283
284	case P_ID_INTEL_PERFORMANCE:
285		return "Intel Performance Code";
286
287	case P_ID_INTEL_DATA:
288		return "Intel Data";
289
290	case P_ID_RESERVED:
291		return "Not Allowed / Reserved for Future Use";
292
293	default:
294		return "Unknown";
295	}
296}
297
298
299static void print_cfi_ident(struct cfi_ident *cfip)
300{
301#if 0
302	if (cfip->qry[0] != 'Q' || cfip->qry[1] != 'R' || cfip->qry[2] != 'Y') {
303		printk("Invalid CFI ident structure.\n");
304		return;
305	}
306#endif
307	printk("Primary Vendor Command Set: %4.4X (%s)\n", cfip->P_ID, vendorname(cfip->P_ID));
308	if (cfip->P_ADR)
309		printk("Primary Algorithm Table at %4.4X\n", cfip->P_ADR);
310	else
311		printk("No Primary Algorithm Table\n");
312
313	printk("Alternative Vendor Command Set: %4.4X (%s)\n", cfip->A_ID, vendorname(cfip->A_ID));
314	if (cfip->A_ADR)
315		printk("Alternate Algorithm Table at %4.4X\n", cfip->A_ADR);
316	else
317		printk("No Alternate Algorithm Table\n");
318
319
320	printk("Vcc Minimum: %2d.%d V\n", cfip->VccMin >> 4, cfip->VccMin & 0xf);
321	printk("Vcc Maximum: %2d.%d V\n", cfip->VccMax >> 4, cfip->VccMax & 0xf);
322	if (cfip->VppMin) {
323		printk("Vpp Minimum: %2d.%d V\n", cfip->VppMin >> 4, cfip->VppMin & 0xf);
324		printk("Vpp Maximum: %2d.%d V\n", cfip->VppMax >> 4, cfip->VppMax & 0xf);
325	}
326	else
327		printk("No Vpp line\n");
328
329	printk("Typical byte/word write timeout: %d µs\n", 1<<cfip->WordWriteTimeoutTyp);
330	printk("Maximum byte/word write timeout: %d µs\n", (1<<cfip->WordWriteTimeoutMax) * (1<<cfip->WordWriteTimeoutTyp));
331
332	if (cfip->BufWriteTimeoutTyp || cfip->BufWriteTimeoutMax) {
333		printk("Typical full buffer write timeout: %d µs\n", 1<<cfip->BufWriteTimeoutTyp);
334		printk("Maximum full buffer write timeout: %d µs\n", (1<<cfip->BufWriteTimeoutMax) * (1<<cfip->BufWriteTimeoutTyp));
335	}
336	else
337		printk("Full buffer write not supported\n");
338
339	printk("Typical block erase timeout: %d ms\n", 1<<cfip->BlockEraseTimeoutTyp);
340	printk("Maximum block erase timeout: %d ms\n", (1<<cfip->BlockEraseTimeoutMax) * (1<<cfip->BlockEraseTimeoutTyp));
341	if (cfip->ChipEraseTimeoutTyp || cfip->ChipEraseTimeoutMax) {
342		printk("Typical chip erase timeout: %d ms\n", 1<<cfip->ChipEraseTimeoutTyp);
343		printk("Maximum chip erase timeout: %d ms\n", (1<<cfip->ChipEraseTimeoutMax) * (1<<cfip->ChipEraseTimeoutTyp));
344	}
345	else
346		printk("Chip erase not supported\n");
347
348	printk("Device size: 0x%X bytes (%d MiB)\n", 1 << cfip->DevSize, 1<< (cfip->DevSize - 20));
349	printk("Flash Device Interface description: 0x%4.4X\n", cfip->InterfaceDesc);
350	switch(cfip->InterfaceDesc) {
351	case CFI_INTERFACE_X8_ASYNC:
352		printk("  - x8-only asynchronous interface\n");
353		break;
354
355	case CFI_INTERFACE_X16_ASYNC:
356		printk("  - x16-only asynchronous interface\n");
357		break;
358
359	case CFI_INTERFACE_X8_BY_X16_ASYNC:
360		printk("  - supports x8 and x16 via BYTE# with asynchronous interface\n");
361		break;
362
363	case CFI_INTERFACE_X32_ASYNC:
364		printk("  - x32-only asynchronous interface\n");
365		break;
366
367	case CFI_INTERFACE_X16_BY_X32_ASYNC:
368		printk("  - supports x16 and x32 via Word# with asynchronous interface\n");
369		break;
370
371	case CFI_INTERFACE_NOT_ALLOWED:
372		printk("  - Not Allowed / Reserved\n");
373		break;
374
375	default:
376		printk("  - Unknown\n");
377		break;
378	}
379
380	printk("Max. bytes in buffer write: 0x%x\n", 1<< cfip->MaxBufWriteSize);
381	printk("Number of Erase Block Regions: %d\n", cfip->NumEraseRegions);
382
383}
384#endif /* DEBUG_CFI */
385
386static struct chip_probe cfi_chip_probe = {
387	.name		= "CFI",
388	.probe_chip	= cfi_probe_chip
389};
390
391struct mtd_info *cfi_probe(struct map_info *map)
392{
393	/*
394	 * Just use the generic probe stuff to call our CFI-specific
395	 * chip_probe routine in all the possible permutations, etc.
396	 */
397	return mtd_do_chip_probe(map, &cfi_chip_probe);
398}
399
400static struct mtd_chip_driver cfi_chipdrv = {
401	.probe		= cfi_probe,
402	.name		= "cfi_probe",
403	.module		= THIS_MODULE
404};
405
406static int __init cfi_probe_init(void)
407{
408	register_mtd_chip_driver(&cfi_chipdrv);
409	return 0;
410}
411
412static void __exit cfi_probe_exit(void)
413{
414	unregister_mtd_chip_driver(&cfi_chipdrv);
415}
416
417module_init(cfi_probe_init);
418module_exit(cfi_probe_exit);
419
420MODULE_LICENSE("GPL");
421MODULE_AUTHOR("David Woodhouse <dwmw2@infradead.org> et al.");
422MODULE_DESCRIPTION("Probe code for CFI-compliant flash chips");
423