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1 | /* drivers/mtd/maps/plat-ram.c | |
2 | * | |
3 | * (c) 2004-2005 Simtec Electronics | |
4 | * http://www.simtec.co.uk/products/SWLINUX/ | |
5 | * Ben Dooks <ben@simtec.co.uk> | |
6 | * | |
7 | * Generic platform device based RAM map | |
8 | * | |
9 | * This program is free software; you can redistribute it and/or modify | |
10 | * it under the terms of the GNU General Public License as published by | |
11 | * the Free Software Foundation; either version 2 of the License, or | |
12 | * (at your option) any later version. | |
13 | * | |
14 | * This program is distributed in the hope that it will be useful, | |
15 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
16 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
17 | * GNU General Public License for more details. | |
18 | * | |
19 | * You should have received a copy of the GNU General Public License | |
20 | * along with this program; if not, write to the Free Software | |
21 | * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA | |
22 | */ | |
23 | ||
24 | #include <linux/module.h> | |
25 | #include <linux/types.h> | |
26 | #include <linux/kernel.h> | |
27 | #include <linux/string.h> | |
28 | #include <linux/ioport.h> | |
29 | #include <linux/device.h> | |
30 | #include <linux/slab.h> | |
31 | #include <linux/platform_device.h> | |
32 | ||
33 | #include <linux/mtd/mtd.h> | |
34 | #include <linux/mtd/map.h> | |
35 | #include <linux/mtd/partitions.h> | |
36 | #include <linux/mtd/plat-ram.h> | |
37 | ||
38 | #include <asm/io.h> | |
39 | ||
40 | /* private structure for each mtd platform ram device created */ | |
41 | ||
42 | struct platram_info { | |
43 | struct device *dev; | |
44 | struct mtd_info *mtd; | |
45 | struct map_info map; | |
46 | struct resource *area; | |
47 | struct platdata_mtd_ram *pdata; | |
48 | }; | |
49 | ||
50 | /* to_platram_info() | |
51 | * | |
52 | * device private data to struct platram_info conversion | |
53 | */ | |
54 | ||
55 | static inline struct platram_info *to_platram_info(struct platform_device *dev) | |
56 | { | |
57 | return platform_get_drvdata(dev); | |
58 | } | |
59 | ||
60 | /* platram_setrw | |
61 | * | |
62 | * call the platform device's set rw/ro control | |
63 | * | |
64 | * to = 0 => read-only | |
65 | * = 1 => read-write | |
66 | */ | |
67 | ||
68 | static inline void platram_setrw(struct platram_info *info, int to) | |
69 | { | |
70 | if (info->pdata == NULL) | |
71 | return; | |
72 | ||
73 | if (info->pdata->set_rw != NULL) | |
74 | (info->pdata->set_rw)(info->dev, to); | |
75 | } | |
76 | ||
77 | /* platram_remove | |
78 | * | |
79 | * called to remove the device from the driver's control | |
80 | */ | |
81 | ||
82 | static int platram_remove(struct platform_device *pdev) | |
83 | { | |
84 | struct platram_info *info = to_platram_info(pdev); | |
85 | ||
86 | dev_dbg(&pdev->dev, "removing device\n"); | |
87 | ||
88 | if (info == NULL) | |
89 | return 0; | |
90 | ||
91 | if (info->mtd) { | |
92 | mtd_device_unregister(info->mtd); | |
93 | map_destroy(info->mtd); | |
94 | } | |
95 | ||
96 | /* ensure ram is left read-only */ | |
97 | ||
98 | platram_setrw(info, PLATRAM_RO); | |
99 | ||
100 | /* release resources */ | |
101 | ||
102 | if (info->area) { | |
103 | release_resource(info->area); | |
104 | kfree(info->area); | |
105 | } | |
106 | ||
107 | if (info->map.virt != NULL) | |
108 | iounmap(info->map.virt); | |
109 | ||
110 | kfree(info); | |
111 | ||
112 | return 0; | |
113 | } | |
114 | ||
115 | /* platram_probe | |
116 | * | |
117 | * called from device drive system when a device matching our | |
118 | * driver is found. | |
119 | */ | |
120 | ||
121 | static int platram_probe(struct platform_device *pdev) | |
122 | { | |
123 | struct platdata_mtd_ram *pdata; | |
124 | struct platram_info *info; | |
125 | struct resource *res; | |
126 | int err = 0; | |
127 | ||
128 | dev_dbg(&pdev->dev, "probe entered\n"); | |
129 | ||
130 | if (dev_get_platdata(&pdev->dev) == NULL) { | |
131 | dev_err(&pdev->dev, "no platform data supplied\n"); | |
132 | err = -ENOENT; | |
133 | goto exit_error; | |
134 | } | |
135 | ||
136 | pdata = dev_get_platdata(&pdev->dev); | |
137 | ||
138 | info = kzalloc(sizeof(*info), GFP_KERNEL); | |
139 | if (info == NULL) { | |
140 | err = -ENOMEM; | |
141 | goto exit_error; | |
142 | } | |
143 | ||
144 | platform_set_drvdata(pdev, info); | |
145 | ||
146 | info->dev = &pdev->dev; | |
147 | info->pdata = pdata; | |
148 | ||
149 | /* get the resource for the memory mapping */ | |
150 | ||
151 | res = platform_get_resource(pdev, IORESOURCE_MEM, 0); | |
152 | ||
153 | if (res == NULL) { | |
154 | dev_err(&pdev->dev, "no memory resource specified\n"); | |
155 | err = -ENOENT; | |
156 | goto exit_free; | |
157 | } | |
158 | ||
159 | dev_dbg(&pdev->dev, "got platform resource %p (0x%llx)\n", res, | |
160 | (unsigned long long)res->start); | |
161 | ||
162 | /* setup map parameters */ | |
163 | ||
164 | info->map.phys = res->start; | |
165 | info->map.size = resource_size(res); | |
166 | info->map.name = pdata->mapname != NULL ? | |
167 | (char *)pdata->mapname : (char *)pdev->name; | |
168 | info->map.bankwidth = pdata->bankwidth; | |
169 | ||
170 | /* register our usage of the memory area */ | |
171 | ||
172 | info->area = request_mem_region(res->start, info->map.size, pdev->name); | |
173 | if (info->area == NULL) { | |
174 | dev_err(&pdev->dev, "failed to request memory region\n"); | |
175 | err = -EIO; | |
176 | goto exit_free; | |
177 | } | |
178 | ||
179 | /* remap the memory area */ | |
180 | ||
181 | info->map.virt = ioremap(res->start, info->map.size); | |
182 | dev_dbg(&pdev->dev, "virt %p, %lu bytes\n", info->map.virt, info->map.size); | |
183 | ||
184 | if (info->map.virt == NULL) { | |
185 | dev_err(&pdev->dev, "failed to ioremap() region\n"); | |
186 | err = -EIO; | |
187 | goto exit_free; | |
188 | } | |
189 | ||
190 | simple_map_init(&info->map); | |
191 | ||
192 | dev_dbg(&pdev->dev, "initialised map, probing for mtd\n"); | |
193 | ||
194 | /* probe for the right mtd map driver | |
195 | * supplied by the platform_data struct */ | |
196 | ||
197 | if (pdata->map_probes) { | |
198 | const char * const *map_probes = pdata->map_probes; | |
199 | ||
200 | for ( ; !info->mtd && *map_probes; map_probes++) | |
201 | info->mtd = do_map_probe(*map_probes , &info->map); | |
202 | } | |
203 | /* fallback to map_ram */ | |
204 | else | |
205 | info->mtd = do_map_probe("map_ram", &info->map); | |
206 | ||
207 | if (info->mtd == NULL) { | |
208 | dev_err(&pdev->dev, "failed to probe for map_ram\n"); | |
209 | err = -ENOMEM; | |
210 | goto exit_free; | |
211 | } | |
212 | ||
213 | info->mtd->dev.parent = &pdev->dev; | |
214 | ||
215 | platram_setrw(info, PLATRAM_RW); | |
216 | ||
217 | /* check to see if there are any available partitions, or whether | |
218 | * to add this device whole */ | |
219 | ||
220 | err = mtd_device_parse_register(info->mtd, pdata->probes, NULL, | |
221 | pdata->partitions, | |
222 | pdata->nr_partitions); | |
223 | if (!err) | |
224 | dev_info(&pdev->dev, "registered mtd device\n"); | |
225 | ||
226 | if (pdata->nr_partitions) { | |
227 | /* add the whole device. */ | |
228 | err = mtd_device_register(info->mtd, NULL, 0); | |
229 | if (err) { | |
230 | dev_err(&pdev->dev, | |
231 | "failed to register the entire device\n"); | |
232 | } | |
233 | } | |
234 | ||
235 | return err; | |
236 | ||
237 | exit_free: | |
238 | platram_remove(pdev); | |
239 | exit_error: | |
240 | return err; | |
241 | } | |
242 | ||
243 | /* device driver info */ | |
244 | ||
245 | /* work with hotplug and coldplug */ | |
246 | MODULE_ALIAS("platform:mtd-ram"); | |
247 | ||
248 | static struct platform_driver platram_driver = { | |
249 | .probe = platram_probe, | |
250 | .remove = platram_remove, | |
251 | .driver = { | |
252 | .name = "mtd-ram", | |
253 | }, | |
254 | }; | |
255 | ||
256 | module_platform_driver(platram_driver); | |
257 | ||
258 | MODULE_LICENSE("GPL"); | |
259 | MODULE_AUTHOR("Ben Dooks <ben@simtec.co.uk>"); | |
260 | MODULE_DESCRIPTION("MTD platform RAM map driver"); |