Merge branch 'linux-next' of git://git.infradead.org/~dedekind/ubi-2.6
[linux-3.10.git] / drivers / mtd / maps / physmap_of.c
1 /*
2  * Flash mappings described by the OF (or flattened) device tree
3  *
4  * Copyright (C) 2006 MontaVista Software Inc.
5  * Author: Vitaly Wool <vwool@ru.mvista.com>
6  *
7  * Revised to handle newer style flash binding by:
8  *   Copyright (C) 2007 David Gibson, IBM Corporation.
9  *
10  * This program is free software; you can redistribute  it and/or modify it
11  * under  the terms of  the GNU General  Public License as published by the
12  * Free Software Foundation;  either version 2 of the  License, or (at your
13  * option) any later version.
14  */
15
16 #include <linux/module.h>
17 #include <linux/types.h>
18 #include <linux/init.h>
19 #include <linux/device.h>
20 #include <linux/mtd/mtd.h>
21 #include <linux/mtd/map.h>
22 #include <linux/mtd/partitions.h>
23 #include <linux/of.h>
24 #include <linux/of_platform.h>
25
26 struct of_flash {
27         struct mtd_info         *mtd;
28         struct map_info         map;
29         struct resource         *res;
30 #ifdef CONFIG_MTD_PARTITIONS
31         struct mtd_partition    *parts;
32 #endif
33 };
34
35 #ifdef CONFIG_MTD_PARTITIONS
36 #define OF_FLASH_PARTS(info)    ((info)->parts)
37
38 static int parse_obsolete_partitions(struct of_device *dev,
39                                      struct of_flash *info,
40                                      struct device_node *dp)
41 {
42         int i, plen, nr_parts;
43         const struct {
44                 u32 offset, len;
45         } *part;
46         const char *names;
47
48         part = of_get_property(dp, "partitions", &plen);
49         if (!part)
50                 return 0; /* No partitions found */
51
52         dev_warn(&dev->dev, "Device tree uses obsolete partition map binding\n");
53
54         nr_parts = plen / sizeof(part[0]);
55
56         info->parts = kzalloc(nr_parts * sizeof(*info->parts), GFP_KERNEL);
57         if (!info->parts)
58                 return -ENOMEM;
59
60         names = of_get_property(dp, "partition-names", &plen);
61
62         for (i = 0; i < nr_parts; i++) {
63                 info->parts[i].offset = part->offset;
64                 info->parts[i].size   = part->len & ~1;
65                 if (part->len & 1) /* bit 0 set signifies read only partition */
66                         info->parts[i].mask_flags = MTD_WRITEABLE;
67
68                 if (names && (plen > 0)) {
69                         int len = strlen(names) + 1;
70
71                         info->parts[i].name = (char *)names;
72                         plen -= len;
73                         names += len;
74                 } else {
75                         info->parts[i].name = "unnamed";
76                 }
77
78                 part++;
79         }
80
81         return nr_parts;
82 }
83 #else /* MTD_PARTITIONS */
84 #define OF_FLASH_PARTS(info)            (0)
85 #define parse_partitions(info, dev)     (0)
86 #endif /* MTD_PARTITIONS */
87
88 static int of_flash_remove(struct of_device *dev)
89 {
90         struct of_flash *info;
91
92         info = dev_get_drvdata(&dev->dev);
93         if (!info)
94                 return 0;
95         dev_set_drvdata(&dev->dev, NULL);
96
97         if (info->mtd) {
98                 if (OF_FLASH_PARTS(info)) {
99                         del_mtd_partitions(info->mtd);
100                         kfree(OF_FLASH_PARTS(info));
101                 } else {
102                         del_mtd_device(info->mtd);
103                 }
104                 map_destroy(info->mtd);
105         }
106
107         if (info->map.virt)
108                 iounmap(info->map.virt);
109
110         if (info->res) {
111                 release_resource(info->res);
112                 kfree(info->res);
113         }
114
115         return 0;
116 }
117
118 /* Helper function to handle probing of the obsolete "direct-mapped"
119  * compatible binding, which has an extra "probe-type" property
120  * describing the type of flash probe necessary. */
121 static struct mtd_info * __devinit obsolete_probe(struct of_device *dev,
122                                                   struct map_info *map)
123 {
124         struct device_node *dp = dev->node;
125         const char *of_probe;
126         struct mtd_info *mtd;
127         static const char *rom_probe_types[]
128                 = { "cfi_probe", "jedec_probe", "map_rom"};
129         int i;
130
131         dev_warn(&dev->dev, "Device tree uses obsolete \"direct-mapped\" "
132                  "flash binding\n");
133
134         of_probe = of_get_property(dp, "probe-type", NULL);
135         if (!of_probe) {
136                 for (i = 0; i < ARRAY_SIZE(rom_probe_types); i++) {
137                         mtd = do_map_probe(rom_probe_types[i], map);
138                         if (mtd)
139                                 return mtd;
140                 }
141                 return NULL;
142         } else if (strcmp(of_probe, "CFI") == 0) {
143                 return do_map_probe("cfi_probe", map);
144         } else if (strcmp(of_probe, "JEDEC") == 0) {
145                 return do_map_probe("jedec_probe", map);
146         } else {
147                 if (strcmp(of_probe, "ROM") != 0)
148                         dev_warn(&dev->dev, "obsolete_probe: don't know probe "
149                                  "type '%s', mapping as rom\n", of_probe);
150                 return do_map_probe("mtd_rom", map);
151         }
152 }
153
154 static int __devinit of_flash_probe(struct of_device *dev,
155                                     const struct of_device_id *match)
156 {
157 #ifdef CONFIG_MTD_PARTITIONS
158         static const char *part_probe_types[]
159                 = { "cmdlinepart", "RedBoot", NULL };
160 #endif
161         struct device_node *dp = dev->node;
162         struct resource res;
163         struct of_flash *info;
164         const char *probe_type = match->data;
165         const u32 *width;
166         int err;
167
168         err = -ENXIO;
169         if (of_address_to_resource(dp, 0, &res)) {
170                 dev_err(&dev->dev, "Can't get IO address from device tree\n");
171                 goto err_out;
172         }
173
174         dev_dbg(&dev->dev, "of_flash device: %.8llx-%.8llx\n",
175                 (unsigned long long)res.start, (unsigned long long)res.end);
176
177         err = -ENOMEM;
178         info = kzalloc(sizeof(*info), GFP_KERNEL);
179         if (!info)
180                 goto err_out;
181
182         dev_set_drvdata(&dev->dev, info);
183
184         err = -EBUSY;
185         info->res = request_mem_region(res.start, res.end - res.start + 1,
186                                        dev->dev.bus_id);
187         if (!info->res)
188                 goto err_out;
189
190         err = -ENXIO;
191         width = of_get_property(dp, "bank-width", NULL);
192         if (!width) {
193                 dev_err(&dev->dev, "Can't get bank width from device tree\n");
194                 goto err_out;
195         }
196
197         info->map.name = dev->dev.bus_id;
198         info->map.phys = res.start;
199         info->map.size = res.end - res.start + 1;
200         info->map.bankwidth = *width;
201
202         err = -ENOMEM;
203         info->map.virt = ioremap(info->map.phys, info->map.size);
204         if (!info->map.virt) {
205                 dev_err(&dev->dev, "Failed to ioremap() flash region\n");
206                 goto err_out;
207         }
208
209         simple_map_init(&info->map);
210
211         if (probe_type)
212                 info->mtd = do_map_probe(probe_type, &info->map);
213         else
214                 info->mtd = obsolete_probe(dev, &info->map);
215
216         err = -ENXIO;
217         if (!info->mtd) {
218                 dev_err(&dev->dev, "do_map_probe() failed\n");
219                 goto err_out;
220         }
221         info->mtd->owner = THIS_MODULE;
222
223 #ifdef CONFIG_MTD_PARTITIONS
224         /* First look for RedBoot table or partitions on the command
225          * line, these take precedence over device tree information */
226         err = parse_mtd_partitions(info->mtd, part_probe_types,
227                                    &info->parts, 0);
228         if (err < 0)
229                 return err;
230
231 #ifdef CONFIG_MTD_OF_PARTS
232         if (err == 0) {
233                 err = of_mtd_parse_partitions(&dev->dev, info->mtd,
234                                               dp, &info->parts);
235                 if (err < 0)
236                         return err;
237         }
238 #endif
239
240         if (err == 0) {
241                 err = parse_obsolete_partitions(dev, info, dp);
242                 if (err < 0)
243                         return err;
244         }
245
246         if (err > 0)
247                 add_mtd_partitions(info->mtd, info->parts, err);
248         else
249 #endif
250                 add_mtd_device(info->mtd);
251
252         return 0;
253
254 err_out:
255         of_flash_remove(dev);
256         return err;
257 }
258
259 static struct of_device_id of_flash_match[] = {
260         {
261                 .compatible     = "cfi-flash",
262                 .data           = (void *)"cfi_probe",
263         },
264         {
265                 /* FIXME: JEDEC chips can't be safely and reliably
266                  * probed, although the mtd code gets it right in
267                  * practice most of the time.  We should use the
268                  * vendor and device ids specified by the binding to
269                  * bypass the heuristic probe code, but the mtd layer
270                  * provides, at present, no interface for doing so
271                  * :(. */
272                 .compatible     = "jedec-flash",
273                 .data           = (void *)"jedec_probe",
274         },
275         {
276                 .type           = "rom",
277                 .compatible     = "direct-mapped"
278         },
279         { },
280 };
281 MODULE_DEVICE_TABLE(of, of_flash_match);
282
283 static struct of_platform_driver of_flash_driver = {
284         .name           = "of-flash",
285         .match_table    = of_flash_match,
286         .probe          = of_flash_probe,
287         .remove         = of_flash_remove,
288 };
289
290 static int __init of_flash_init(void)
291 {
292         return of_register_platform_driver(&of_flash_driver);
293 }
294
295 static void __exit of_flash_exit(void)
296 {
297         of_unregister_platform_driver(&of_flash_driver);
298 }
299
300 module_init(of_flash_init);
301 module_exit(of_flash_exit);
302
303 MODULE_LICENSE("GPL");
304 MODULE_AUTHOR("Vitaly Wool <vwool@ru.mvista.com>");
305 MODULE_DESCRIPTION("Device tree based MTD map driver");