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  • only in /asuswrt-rt-n18u-9.0.0.4.380.2695/release/src-rt-6.x.4708/linux/linux-2.6/drivers/mtd/chips/
1/*
2 * Routines common to all CFI-type probes.
3 * (C) 2001-2003 Red Hat, Inc.
4 * GPL'd
5 */
6
7#include <linux/kernel.h>
8#include <linux/slab.h>
9#include <linux/module.h>
10#include <linux/mtd/mtd.h>
11#include <linux/mtd/map.h>
12#include <linux/mtd/cfi.h>
13#include <linux/mtd/gen_probe.h>
14
15static struct mtd_info *check_cmd_set(struct map_info *, int);
16static struct cfi_private *genprobe_ident_chips(struct map_info *map,
17						struct chip_probe *cp);
18static int genprobe_new_chip(struct map_info *map, struct chip_probe *cp,
19			     struct cfi_private *cfi);
20
21struct mtd_info *mtd_do_chip_probe(struct map_info *map, struct chip_probe *cp)
22{
23	struct mtd_info *mtd = NULL;
24	struct cfi_private *cfi;
25
26	/* First probe the map to see if we have CFI stuff there. */
27	cfi = genprobe_ident_chips(map, cp);
28
29	if (!cfi)
30		return NULL;
31
32	map->fldrv_priv = cfi;
33	/* OK we liked it. Now find a driver for the command set it talks */
34
35	mtd = check_cmd_set(map, 1); /* First the primary cmdset */
36	if (!mtd)
37		mtd = check_cmd_set(map, 0); /* Then the secondary */
38
39	if (mtd) {
40		if (mtd->size > map->size) {
41			printk(KERN_WARNING "Reducing visibility of %ldKiB chip to %ldKiB\n",
42			       (unsigned long)mtd->size >> 10,
43			       (unsigned long)map->size >> 10);
44			mtd->size = map->size;
45		}
46		return mtd;
47	}
48
49	printk(KERN_WARNING"gen_probe: No supported Vendor Command Set found\n");
50
51	kfree(cfi->cfiq);
52	kfree(cfi);
53	map->fldrv_priv = NULL;
54	return NULL;
55}
56EXPORT_SYMBOL(mtd_do_chip_probe);
57
58
59static struct cfi_private *genprobe_ident_chips(struct map_info *map, struct chip_probe *cp)
60{
61	struct cfi_private cfi;
62	struct cfi_private *retcfi;
63	unsigned long *chip_map;
64	int i, j, mapsize;
65	int max_chips;
66
67	memset(&cfi, 0, sizeof(cfi));
68
69	/* Call the probetype-specific code with all permutations of
70	   interleave and device type, etc. */
71	if (!genprobe_new_chip(map, cp, &cfi)) {
72		/* The probe didn't like it */
73		pr_debug("%s: Found no %s device at location zero\n",
74			 cp->name, map->name);
75		return NULL;
76	}
77
78#if 0 /* Let the CFI probe routine do this sanity check. The Intel and AMD
79	 probe routines won't ever return a broken CFI structure anyway,
80	 because they make them up themselves.
81      */
82	if (cfi.cfiq->NumEraseRegions == 0) {
83		printk(KERN_WARNING "Number of erase regions is zero\n");
84		kfree(cfi.cfiq);
85		return NULL;
86	}
87#endif
88	cfi.chipshift = cfi.cfiq->DevSize;
89
90	if (cfi_interleave_is_1(&cfi)) {
91		;
92	} else if (cfi_interleave_is_2(&cfi)) {
93		cfi.chipshift++;
94	} else if (cfi_interleave_is_4((&cfi))) {
95		cfi.chipshift += 2;
96	} else if (cfi_interleave_is_8(&cfi)) {
97		cfi.chipshift += 3;
98	} else {
99		BUG();
100	}
101
102	cfi.numchips = 1;
103
104	/*
105	 * Allocate memory for bitmap of valid chips.
106	 * Align bitmap storage size to full byte.
107	 */
108	max_chips = map->size >> cfi.chipshift;
109	if (!max_chips) {
110		printk(KERN_WARNING "NOR chip too large to fit in mapping. Attempting to cope...\n");
111		max_chips = 1;
112	}
113
114	mapsize = sizeof(long) * DIV_ROUND_UP(max_chips, BITS_PER_LONG);
115	chip_map = kzalloc(mapsize, GFP_KERNEL);
116	if (!chip_map) {
117		printk(KERN_WARNING "%s: kmalloc failed for CFI chip map\n", map->name);
118		kfree(cfi.cfiq);
119		return NULL;
120	}
121
122	set_bit(0, chip_map); /* Mark first chip valid */
123
124	/*
125	 * Now probe for other chips, checking sensibly for aliases while
126	 * we're at it. The new_chip probe above should have let the first
127	 * chip in read mode.
128	 */
129
130	for (i = 1; i < max_chips; i++) {
131		cp->probe_chip(map, i << cfi.chipshift, chip_map, &cfi);
132	}
133
134	/*
135	 * Now allocate the space for the structures we need to return to
136	 * our caller, and copy the appropriate data into them.
137	 */
138
139	retcfi = kmalloc(sizeof(struct cfi_private) + cfi.numchips * sizeof(struct flchip), GFP_KERNEL);
140
141	if (!retcfi) {
142		printk(KERN_WARNING "%s: kmalloc failed for CFI private structure\n", map->name);
143		kfree(cfi.cfiq);
144		kfree(chip_map);
145		return NULL;
146	}
147
148	memcpy(retcfi, &cfi, sizeof(cfi));
149	memset(&retcfi->chips[0], 0, sizeof(struct flchip) * cfi.numchips);
150
151	for (i = 0, j = 0; (j < cfi.numchips) && (i < max_chips); i++) {
152		if(test_bit(i, chip_map)) {
153			struct flchip *pchip = &retcfi->chips[j++];
154
155			pchip->start = (i << cfi.chipshift);
156			pchip->state = FL_READY;
157			init_waitqueue_head(&pchip->wq);
158			mutex_init(&pchip->mutex);
159		}
160	}
161
162	kfree(chip_map);
163	return retcfi;
164}
165
166
167static int genprobe_new_chip(struct map_info *map, struct chip_probe *cp,
168			     struct cfi_private *cfi)
169{
170	int min_chips = (map_bankwidth(map)/4?:1); /* At most 4-bytes wide. */
171	int max_chips = map_bankwidth(map); /* And minimum 1 */
172	int nr_chips, type;
173
174	for (nr_chips = max_chips; nr_chips >= min_chips; nr_chips >>= 1) {
175
176		if (!cfi_interleave_supported(nr_chips))
177		    continue;
178
179		cfi->interleave = nr_chips;
180
181		/* Minimum device size. Don't look for one 8-bit device
182		   in a 16-bit bus, etc. */
183		type = map_bankwidth(map) / nr_chips;
184
185		for (; type <= CFI_DEVICETYPE_X32; type<<=1) {
186			cfi->device_type = type;
187
188			if (cp->probe_chip(map, 0, NULL, cfi))
189				return 1;
190		}
191	}
192	return 0;
193}
194
195typedef struct mtd_info *cfi_cmdset_fn_t(struct map_info *, int);
196
197extern cfi_cmdset_fn_t cfi_cmdset_0001;
198extern cfi_cmdset_fn_t cfi_cmdset_0002;
199extern cfi_cmdset_fn_t cfi_cmdset_0020;
200
201static inline struct mtd_info *cfi_cmdset_unknown(struct map_info *map,
202						  int primary)
203{
204	struct cfi_private *cfi = map->fldrv_priv;
205	__u16 type = primary?cfi->cfiq->P_ID:cfi->cfiq->A_ID;
206#ifdef CONFIG_MODULES
207	char probename[16+sizeof(MODULE_SYMBOL_PREFIX)];
208	cfi_cmdset_fn_t *probe_function;
209
210	sprintf(probename, MODULE_SYMBOL_PREFIX "cfi_cmdset_%4.4X", type);
211
212	probe_function = __symbol_get(probename);
213	if (!probe_function) {
214		request_module(probename + sizeof(MODULE_SYMBOL_PREFIX) - 1);
215		probe_function = __symbol_get(probename);
216	}
217
218	if (probe_function) {
219		struct mtd_info *mtd;
220
221		mtd = (*probe_function)(map, primary);
222		/* If it was happy, it'll have increased its own use count */
223		symbol_put_addr(probe_function);
224		return mtd;
225	}
226#endif
227	printk(KERN_NOTICE "Support for command set %04X not present\n", type);
228
229	return NULL;
230}
231
232static struct mtd_info *check_cmd_set(struct map_info *map, int primary)
233{
234	struct cfi_private *cfi = map->fldrv_priv;
235	__u16 type = primary?cfi->cfiq->P_ID:cfi->cfiq->A_ID;
236
237	if (type == P_ID_NONE || type == P_ID_RESERVED)
238		return NULL;
239
240	switch(type){
241		/* We need these for the !CONFIG_MODULES case,
242		   because symbol_get() doesn't work there */
243#ifdef CONFIG_MTD_CFI_INTELEXT
244	case P_ID_INTEL_EXT:
245	case P_ID_INTEL_STD:
246	case P_ID_INTEL_PERFORMANCE:
247		return cfi_cmdset_0001(map, primary);
248#endif
249#ifdef CONFIG_MTD_CFI_AMDSTD
250	case P_ID_AMD_STD:
251	case P_ID_SST_OLD:
252	case P_ID_WINBOND:
253		return cfi_cmdset_0002(map, primary);
254#endif
255#ifdef CONFIG_MTD_CFI_STAA
256        case P_ID_ST_ADV:
257		return cfi_cmdset_0020(map, primary);
258#endif
259	default:
260		return cfi_cmdset_unknown(map, primary);
261	}
262}
263
264MODULE_LICENSE("GPL");
265MODULE_AUTHOR("David Woodhouse <dwmw2@infradead.org>");
266MODULE_DESCRIPTION("Helper routines for flash chip probe code");
267