xref: /openbmc/linux/drivers/mtd/chips/gen_probe.c (revision 9b93eb47)
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 
15 static struct mtd_info *check_cmd_set(struct map_info *, int);
16 static struct cfi_private *genprobe_ident_chips(struct map_info *map,
17 						struct chip_probe *cp);
18 static int genprobe_new_chip(struct map_info *map, struct chip_probe *cp,
19 			     struct cfi_private *cfi);
20 
21 struct 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 }
56 EXPORT_SYMBOL(mtd_do_chip_probe);
57 
58 
59 static 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 		kfree(cfi.cfiq);
118 		return NULL;
119 	}
120 
121 	set_bit(0, chip_map); /* Mark first chip valid */
122 
123 	/*
124 	 * Now probe for other chips, checking sensibly for aliases while
125 	 * we're at it. The new_chip probe above should have let the first
126 	 * chip in read mode.
127 	 */
128 
129 	for (i = 1; i < max_chips; i++) {
130 		cp->probe_chip(map, i << cfi.chipshift, chip_map, &cfi);
131 	}
132 
133 	/*
134 	 * Now allocate the space for the structures we need to return to
135 	 * our caller, and copy the appropriate data into them.
136 	 */
137 
138 	retcfi = kmalloc(struct_size(retcfi, chips, cfi.numchips), GFP_KERNEL);
139 
140 	if (!retcfi) {
141 		kfree(cfi.cfiq);
142 		kfree(chip_map);
143 		return NULL;
144 	}
145 
146 	memcpy(retcfi, &cfi, sizeof(cfi));
147 	memset(&retcfi->chips[0], 0, sizeof(struct flchip) * cfi.numchips);
148 
149 	for (i = 0, j = 0; (j < cfi.numchips) && (i < max_chips); i++) {
150 		if(test_bit(i, chip_map)) {
151 			struct flchip *pchip = &retcfi->chips[j++];
152 
153 			pchip->start = (i << cfi.chipshift);
154 			pchip->state = FL_READY;
155 			init_waitqueue_head(&pchip->wq);
156 			mutex_init(&pchip->mutex);
157 		}
158 	}
159 
160 	kfree(chip_map);
161 	return retcfi;
162 }
163 
164 
165 static int genprobe_new_chip(struct map_info *map, struct chip_probe *cp,
166 			     struct cfi_private *cfi)
167 {
168 	int min_chips = (map_bankwidth(map)/4?:1); /* At most 4-bytes wide. */
169 	int max_chips = map_bankwidth(map); /* And minimum 1 */
170 	int nr_chips, type;
171 
172 	for (nr_chips = max_chips; nr_chips >= min_chips; nr_chips >>= 1) {
173 
174 		if (!cfi_interleave_supported(nr_chips))
175 		    continue;
176 
177 		cfi->interleave = nr_chips;
178 
179 		/* Minimum device size. Don't look for one 8-bit device
180 		   in a 16-bit bus, etc. */
181 		type = map_bankwidth(map) / nr_chips;
182 
183 		for (; type <= CFI_DEVICETYPE_X32; type<<=1) {
184 			cfi->device_type = type;
185 
186 			if (cp->probe_chip(map, 0, NULL, cfi))
187 				return 1;
188 		}
189 	}
190 	return 0;
191 }
192 
193 typedef struct mtd_info *cfi_cmdset_fn_t(struct map_info *, int);
194 
195 extern cfi_cmdset_fn_t cfi_cmdset_0001;
196 extern cfi_cmdset_fn_t cfi_cmdset_0002;
197 extern cfi_cmdset_fn_t cfi_cmdset_0020;
198 
199 static inline struct mtd_info *cfi_cmdset_unknown(struct map_info *map,
200 						  int primary)
201 {
202 	struct cfi_private *cfi = map->fldrv_priv;
203 	__u16 type = primary?cfi->cfiq->P_ID:cfi->cfiq->A_ID;
204 #ifdef CONFIG_MODULES
205 	cfi_cmdset_fn_t *probe_function;
206 	char *probename;
207 
208 	probename = kasprintf(GFP_KERNEL, "cfi_cmdset_%4.4X", type);
209 	if (!probename)
210 		return NULL;
211 
212 	probe_function = __symbol_get(probename);
213 	if (!probe_function) {
214 		request_module("cfi_cmdset_%4.4X", type);
215 		probe_function = __symbol_get(probename);
216 	}
217 	kfree(probename);
218 
219 	if (probe_function) {
220 		struct mtd_info *mtd;
221 
222 		mtd = (*probe_function)(map, primary);
223 		/* If it was happy, it'll have increased its own use count */
224 		symbol_put_addr(probe_function);
225 		return mtd;
226 	}
227 #endif
228 	printk(KERN_NOTICE "Support for command set %04X not present\n", type);
229 
230 	return NULL;
231 }
232 
233 static struct mtd_info *check_cmd_set(struct map_info *map, int primary)
234 {
235 	struct cfi_private *cfi = map->fldrv_priv;
236 	__u16 type = primary?cfi->cfiq->P_ID:cfi->cfiq->A_ID;
237 
238 	if (type == P_ID_NONE || type == P_ID_RESERVED)
239 		return NULL;
240 
241 	switch(type){
242 		/* We need these for the !CONFIG_MODULES case,
243 		   because symbol_get() doesn't work there */
244 #ifdef CONFIG_MTD_CFI_INTELEXT
245 	case P_ID_INTEL_EXT:
246 	case P_ID_INTEL_STD:
247 	case P_ID_INTEL_PERFORMANCE:
248 		return cfi_cmdset_0001(map, primary);
249 #endif
250 #ifdef CONFIG_MTD_CFI_AMDSTD
251 	case P_ID_AMD_STD:
252 	case P_ID_SST_OLD:
253 	case P_ID_WINBOND:
254 		return cfi_cmdset_0002(map, primary);
255 #endif
256 #ifdef CONFIG_MTD_CFI_STAA
257         case P_ID_ST_ADV:
258 		return cfi_cmdset_0020(map, primary);
259 #endif
260 	default:
261 		return cfi_cmdset_unknown(map, primary);
262 	}
263 }
264 
265 MODULE_LICENSE("GPL");
266 MODULE_AUTHOR("David Woodhouse <dwmw2@infradead.org>");
267 MODULE_DESCRIPTION("Helper routines for flash chip probe code");
268