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		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(sizeof(struct cfi_private) + cfi.numchips * sizeof(struct flchip), 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
165static 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
193typedef struct mtd_info *cfi_cmdset_fn_t(struct map_info *, int);
194
195extern cfi_cmdset_fn_t cfi_cmdset_0001;
196extern cfi_cmdset_fn_t cfi_cmdset_0002;
197extern cfi_cmdset_fn_t cfi_cmdset_0020;
198
199static 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	char probename[sizeof(VMLINUX_SYMBOL_STR(cfi_cmdset_%4.4X))];
206	cfi_cmdset_fn_t *probe_function;
207
208	sprintf(probename, VMLINUX_SYMBOL_STR(cfi_cmdset_%4.4X), type);
209
210	probe_function = __symbol_get(probename);
211	if (!probe_function) {
212		request_module("cfi_cmdset_%4.4X", type);
213		probe_function = __symbol_get(probename);
214	}
215
216	if (probe_function) {
217		struct mtd_info *mtd;
218
219		mtd = (*probe_function)(map, primary);
220		/* If it was happy, it'll have increased its own use count */
221		symbol_put_addr(probe_function);
222		return mtd;
223	}
224#endif
225	printk(KERN_NOTICE "Support for command set %04X not present\n", type);
226
227	return NULL;
228}
229
230static struct mtd_info *check_cmd_set(struct map_info *map, int primary)
231{
232	struct cfi_private *cfi = map->fldrv_priv;
233	__u16 type = primary?cfi->cfiq->P_ID:cfi->cfiq->A_ID;
234
235	if (type == P_ID_NONE || type == P_ID_RESERVED)
236		return NULL;
237
238	switch(type){
239		/* We need these for the !CONFIG_MODULES case,
240		   because symbol_get() doesn't work there */
241#ifdef CONFIG_MTD_CFI_INTELEXT
242	case P_ID_INTEL_EXT:
243	case P_ID_INTEL_STD:
244	case P_ID_INTEL_PERFORMANCE:
245		return cfi_cmdset_0001(map, primary);
246#endif
247#ifdef CONFIG_MTD_CFI_AMDSTD
248	case P_ID_AMD_STD:
249	case P_ID_SST_OLD:
250	case P_ID_WINBOND:
251		return cfi_cmdset_0002(map, primary);
252#endif
253#ifdef CONFIG_MTD_CFI_STAA
254        case P_ID_ST_ADV:
255		return cfi_cmdset_0020(map, primary);
256#endif
257	default:
258		return cfi_cmdset_unknown(map, primary);
259	}
260}
261
262MODULE_LICENSE("GPL");
263MODULE_AUTHOR("David Woodhouse <dwmw2@infradead.org>");
264MODULE_DESCRIPTION("Helper routines for flash chip probe code");
265