xref: /openbmc/linux/drivers/mtd/chips/gen_probe.c (revision 87c2ce3b)
1 /*
2  * Routines common to all CFI-type probes.
3  * (C) 2001-2003 Red Hat, Inc.
4  * GPL'd
5  * $Id: gen_probe.c,v 1.24 2005/11/07 11:14:23 gleixner Exp $
6  */
7 
8 #include <linux/kernel.h>
9 #include <linux/slab.h>
10 #include <linux/module.h>
11 #include <linux/mtd/mtd.h>
12 #include <linux/mtd/map.h>
13 #include <linux/mtd/cfi.h>
14 #include <linux/mtd/gen_probe.h>
15 
16 static struct mtd_info *check_cmd_set(struct map_info *, int);
17 static struct cfi_private *genprobe_ident_chips(struct map_info *map,
18 						struct chip_probe *cp);
19 static int genprobe_new_chip(struct map_info *map, struct chip_probe *cp,
20 			     struct cfi_private *cfi);
21 
22 struct mtd_info *mtd_do_chip_probe(struct map_info *map, struct chip_probe *cp)
23 {
24 	struct mtd_info *mtd = NULL;
25 	struct cfi_private *cfi;
26 
27 	/* First probe the map to see if we have CFI stuff there. */
28 	cfi = genprobe_ident_chips(map, cp);
29 
30 	if (!cfi)
31 		return NULL;
32 
33 	map->fldrv_priv = cfi;
34 	/* OK we liked it. Now find a driver for the command set it talks */
35 
36 	mtd = check_cmd_set(map, 1); /* First the primary cmdset */
37 	if (!mtd)
38 		mtd = check_cmd_set(map, 0); /* Then the secondary */
39 
40 	if (mtd)
41 		return mtd;
42 
43 	printk(KERN_WARNING"gen_probe: No supported Vendor Command Set found\n");
44 
45 	kfree(cfi->cfiq);
46 	kfree(cfi);
47 	map->fldrv_priv = NULL;
48 	return NULL;
49 }
50 EXPORT_SYMBOL(mtd_do_chip_probe);
51 
52 
53 static struct cfi_private *genprobe_ident_chips(struct map_info *map, struct chip_probe *cp)
54 {
55 	struct cfi_private cfi;
56 	struct cfi_private *retcfi;
57 	unsigned long *chip_map;
58 	int i, j, mapsize;
59 	int max_chips;
60 
61 	memset(&cfi, 0, sizeof(cfi));
62 
63 	/* Call the probetype-specific code with all permutations of
64 	   interleave and device type, etc. */
65 	if (!genprobe_new_chip(map, cp, &cfi)) {
66 		/* The probe didn't like it */
67 		printk(KERN_DEBUG "%s: Found no %s device at location zero\n",
68 		       cp->name, map->name);
69 		return NULL;
70 	}
71 
72 #if 0 /* Let the CFI probe routine do this sanity check. The Intel and AMD
73 	 probe routines won't ever return a broken CFI structure anyway,
74 	 because they make them up themselves.
75       */
76 	if (cfi.cfiq->NumEraseRegions == 0) {
77 		printk(KERN_WARNING "Number of erase regions is zero\n");
78 		kfree(cfi.cfiq);
79 		return NULL;
80 	}
81 #endif
82 	cfi.chipshift = cfi.cfiq->DevSize;
83 
84 	if (cfi_interleave_is_1(&cfi)) {
85 		;
86 	} else if (cfi_interleave_is_2(&cfi)) {
87 		cfi.chipshift++;
88 	} else if (cfi_interleave_is_4((&cfi))) {
89 		cfi.chipshift += 2;
90 	} else if (cfi_interleave_is_8(&cfi)) {
91 		cfi.chipshift += 3;
92 	} else {
93 		BUG();
94 	}
95 
96 	cfi.numchips = 1;
97 
98 	/*
99 	 * Allocate memory for bitmap of valid chips.
100 	 * Align bitmap storage size to full byte.
101 	 */
102 	max_chips = map->size >> cfi.chipshift;
103 	mapsize = (max_chips / 8) + ((max_chips % 8) ? 1 : 0);
104 	chip_map = kmalloc(mapsize, GFP_KERNEL);
105 	if (!chip_map) {
106 		printk(KERN_WARNING "%s: kmalloc failed for CFI chip map\n", map->name);
107 		kfree(cfi.cfiq);
108 		return NULL;
109 	}
110 	memset (chip_map, 0, mapsize);
111 
112 	set_bit(0, chip_map); /* Mark first chip valid */
113 
114 	/*
115 	 * Now probe for other chips, checking sensibly for aliases while
116 	 * we're at it. The new_chip probe above should have let the first
117 	 * chip in read mode.
118 	 */
119 
120 	for (i = 1; i < max_chips; i++) {
121 		cp->probe_chip(map, i << cfi.chipshift, chip_map, &cfi);
122 	}
123 
124 	/*
125 	 * Now allocate the space for the structures we need to return to
126 	 * our caller, and copy the appropriate data into them.
127 	 */
128 
129 	retcfi = kmalloc(sizeof(struct cfi_private) + cfi.numchips * sizeof(struct flchip), GFP_KERNEL);
130 
131 	if (!retcfi) {
132 		printk(KERN_WARNING "%s: kmalloc failed for CFI private structure\n", map->name);
133 		kfree(cfi.cfiq);
134 		kfree(chip_map);
135 		return NULL;
136 	}
137 
138 	memcpy(retcfi, &cfi, sizeof(cfi));
139 	memset(&retcfi->chips[0], 0, sizeof(struct flchip) * cfi.numchips);
140 
141 	for (i = 0, j = 0; (j < cfi.numchips) && (i < max_chips); i++) {
142 		if(test_bit(i, chip_map)) {
143 			struct flchip *pchip = &retcfi->chips[j++];
144 
145 			pchip->start = (i << cfi.chipshift);
146 			pchip->state = FL_READY;
147 			init_waitqueue_head(&pchip->wq);
148 			spin_lock_init(&pchip->_spinlock);
149 			pchip->mutex = &pchip->_spinlock;
150 		}
151 	}
152 
153 	kfree(chip_map);
154 	return retcfi;
155 }
156 
157 
158 static int genprobe_new_chip(struct map_info *map, struct chip_probe *cp,
159 			     struct cfi_private *cfi)
160 {
161 	int min_chips = (map_bankwidth(map)/4?:1); /* At most 4-bytes wide. */
162 	int max_chips = map_bankwidth(map); /* And minimum 1 */
163 	int nr_chips, type;
164 
165 	for (nr_chips = max_chips; nr_chips >= min_chips; nr_chips >>= 1) {
166 
167 		if (!cfi_interleave_supported(nr_chips))
168 		    continue;
169 
170 		cfi->interleave = nr_chips;
171 
172 		/* Minimum device size. Don't look for one 8-bit device
173 		   in a 16-bit bus, etc. */
174 		type = map_bankwidth(map) / nr_chips;
175 
176 		for (; type <= CFI_DEVICETYPE_X32; type<<=1) {
177 			cfi->device_type = type;
178 
179 			if (cp->probe_chip(map, 0, NULL, cfi))
180 				return 1;
181 		}
182 	}
183 	return 0;
184 }
185 
186 typedef struct mtd_info *cfi_cmdset_fn_t(struct map_info *, int);
187 
188 extern cfi_cmdset_fn_t cfi_cmdset_0001;
189 extern cfi_cmdset_fn_t cfi_cmdset_0002;
190 extern cfi_cmdset_fn_t cfi_cmdset_0020;
191 
192 static inline struct mtd_info *cfi_cmdset_unknown(struct map_info *map,
193 						  int primary)
194 {
195 	struct cfi_private *cfi = map->fldrv_priv;
196 	__u16 type = primary?cfi->cfiq->P_ID:cfi->cfiq->A_ID;
197 #if defined(CONFIG_MODULES) && defined(HAVE_INTER_MODULE)
198 	char probename[32];
199 	cfi_cmdset_fn_t *probe_function;
200 
201 	sprintf(probename, "cfi_cmdset_%4.4X", type);
202 
203 	probe_function = inter_module_get_request(probename, probename);
204 
205 	if (probe_function) {
206 		struct mtd_info *mtd;
207 
208 		mtd = (*probe_function)(map, primary);
209 		/* If it was happy, it'll have increased its own use count */
210 		inter_module_put(probename);
211 		return mtd;
212 	}
213 #endif
214 	printk(KERN_NOTICE "Support for command set %04X not present\n",
215 	       type);
216 
217 	return NULL;
218 }
219 
220 static struct mtd_info *check_cmd_set(struct map_info *map, int primary)
221 {
222 	struct cfi_private *cfi = map->fldrv_priv;
223 	__u16 type = primary?cfi->cfiq->P_ID:cfi->cfiq->A_ID;
224 
225 	if (type == P_ID_NONE || type == P_ID_RESERVED)
226 		return NULL;
227 
228 	switch(type){
229 		/* Urgh. Ifdefs. The version with weak symbols was
230 		 * _much_ nicer. Shame it didn't seem to work on
231 		 * anything but x86, really.
232 		 * But we can't rely in inter_module_get() because
233 		 * that'd mean we depend on link order.
234 		 */
235 #ifdef CONFIG_MTD_CFI_INTELEXT
236 	case 0x0001:
237 	case 0x0003:
238 	case 0x0200:
239 		return cfi_cmdset_0001(map, primary);
240 #endif
241 #ifdef CONFIG_MTD_CFI_AMDSTD
242 	case 0x0002:
243 		return cfi_cmdset_0002(map, primary);
244 #endif
245 #ifdef CONFIG_MTD_CFI_STAA
246         case 0x0020:
247 		return cfi_cmdset_0020(map, primary);
248 #endif
249 	}
250 
251 	return cfi_cmdset_unknown(map, primary);
252 }
253 
254 MODULE_LICENSE("GPL");
255 MODULE_AUTHOR("David Woodhouse <dwmw2@infradead.org>");
256 MODULE_DESCRIPTION("Helper routines for flash chip probe code");
257