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/init.h>
27 #include <linux/kernel.h>
28 #include <linux/string.h>
29 #include <linux/ioport.h>
30 #include <linux/device.h>
31 #include <linux/slab.h>
32 #include <linux/platform_device.h>
33
34 #include <linux/mtd/mtd.h>
35 #include <linux/mtd/map.h>
36 #include <linux/mtd/partitions.h>
37 #include <linux/mtd/plat-ram.h>
38
39 #include <asm/io.h>
40
41 /* private structure for each mtd platform ram device created */
42
43 struct platram_info {
44 struct device *dev;
45 struct mtd_info *mtd;
46 struct map_info map;
47 struct resource *area;
48 struct platdata_mtd_ram *pdata;
49 };
50
51 /* to_platram_info()
52 *
53 * device private data to struct platram_info conversion
54 */
55
to_platram_info(struct platform_device * dev)56 static inline struct platram_info *to_platram_info(struct platform_device *dev)
57 {
58 return (struct platram_info *)platform_get_drvdata(dev);
59 }
60
61 /* platram_setrw
62 *
63 * call the platform device's set rw/ro control
64 *
65 * to = 0 => read-only
66 * = 1 => read-write
67 */
68
platram_setrw(struct platram_info * info,int to)69 static inline void platram_setrw(struct platram_info *info, int to)
70 {
71 if (info->pdata == NULL)
72 return;
73
74 if (info->pdata->set_rw != NULL)
75 (info->pdata->set_rw)(info->dev, to);
76 }
77
78 /* platram_remove
79 *
80 * called to remove the device from the driver's control
81 */
82
platram_remove(struct platform_device * pdev)83 static int platram_remove(struct platform_device *pdev)
84 {
85 struct platram_info *info = to_platram_info(pdev);
86
87 platform_set_drvdata(pdev, NULL);
88
89 dev_dbg(&pdev->dev, "removing device\n");
90
91 if (info == NULL)
92 return 0;
93
94 if (info->mtd) {
95 mtd_device_unregister(info->mtd);
96 map_destroy(info->mtd);
97 }
98
99 /* ensure ram is left read-only */
100
101 platram_setrw(info, PLATRAM_RO);
102
103 /* release resources */
104
105 if (info->area) {
106 release_resource(info->area);
107 kfree(info->area);
108 }
109
110 if (info->map.virt != NULL)
111 iounmap(info->map.virt);
112
113 kfree(info);
114
115 return 0;
116 }
117
118 /* platram_probe
119 *
120 * called from device drive system when a device matching our
121 * driver is found.
122 */
123
platram_probe(struct platform_device * pdev)124 static int platram_probe(struct platform_device *pdev)
125 {
126 struct platdata_mtd_ram *pdata;
127 struct platram_info *info;
128 struct resource *res;
129 int err = 0;
130
131 dev_dbg(&pdev->dev, "probe entered\n");
132
133 if (pdev->dev.platform_data == NULL) {
134 dev_err(&pdev->dev, "no platform data supplied\n");
135 err = -ENOENT;
136 goto exit_error;
137 }
138
139 pdata = pdev->dev.platform_data;
140
141 info = kzalloc(sizeof(*info), GFP_KERNEL);
142 if (info == NULL) {
143 dev_err(&pdev->dev, "no memory for flash info\n");
144 err = -ENOMEM;
145 goto exit_error;
146 }
147
148 platform_set_drvdata(pdev, info);
149
150 info->dev = &pdev->dev;
151 info->pdata = pdata;
152
153 /* get the resource for the memory mapping */
154
155 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
156
157 if (res == NULL) {
158 dev_err(&pdev->dev, "no memory resource specified\n");
159 err = -ENOENT;
160 goto exit_free;
161 }
162
163 dev_dbg(&pdev->dev, "got platform resource %p (0x%llx)\n", res,
164 (unsigned long long)res->start);
165
166 /* setup map parameters */
167
168 info->map.phys = res->start;
169 info->map.size = resource_size(res);
170 info->map.name = pdata->mapname != NULL ?
171 (char *)pdata->mapname : (char *)pdev->name;
172 info->map.bankwidth = pdata->bankwidth;
173
174 /* register our usage of the memory area */
175
176 info->area = request_mem_region(res->start, info->map.size, pdev->name);
177 if (info->area == NULL) {
178 dev_err(&pdev->dev, "failed to request memory region\n");
179 err = -EIO;
180 goto exit_free;
181 }
182
183 /* remap the memory area */
184
185 info->map.virt = ioremap(res->start, info->map.size);
186 dev_dbg(&pdev->dev, "virt %p, %lu bytes\n", info->map.virt, info->map.size);
187
188 if (info->map.virt == NULL) {
189 dev_err(&pdev->dev, "failed to ioremap() region\n");
190 err = -EIO;
191 goto exit_free;
192 }
193
194 simple_map_init(&info->map);
195
196 dev_dbg(&pdev->dev, "initialised map, probing for mtd\n");
197
198 /* probe for the right mtd map driver
199 * supplied by the platform_data struct */
200
201 if (pdata->map_probes) {
202 const char * const *map_probes = pdata->map_probes;
203
204 for ( ; !info->mtd && *map_probes; map_probes++)
205 info->mtd = do_map_probe(*map_probes , &info->map);
206 }
207 /* fallback to map_ram */
208 else
209 info->mtd = do_map_probe("map_ram", &info->map);
210
211 if (info->mtd == NULL) {
212 dev_err(&pdev->dev, "failed to probe for map_ram\n");
213 err = -ENOMEM;
214 goto exit_free;
215 }
216
217 info->mtd->owner = THIS_MODULE;
218 info->mtd->dev.parent = &pdev->dev;
219
220 platram_setrw(info, PLATRAM_RW);
221
222 /* check to see if there are any available partitions, or whether
223 * to add this device whole */
224
225 err = mtd_device_parse_register(info->mtd, pdata->probes, NULL,
226 pdata->partitions,
227 pdata->nr_partitions);
228 if (!err)
229 dev_info(&pdev->dev, "registered mtd device\n");
230
231 if (pdata->nr_partitions) {
232 /* add the whole device. */
233 err = mtd_device_register(info->mtd, NULL, 0);
234 if (err) {
235 dev_err(&pdev->dev,
236 "failed to register the entire device\n");
237 }
238 }
239
240 return err;
241
242 exit_free:
243 platram_remove(pdev);
244 exit_error:
245 return err;
246 }
247
248 /* device driver info */
249
250 /* work with hotplug and coldplug */
251 MODULE_ALIAS("platform:mtd-ram");
252
253 static struct platform_driver platram_driver = {
254 .probe = platram_probe,
255 .remove = platram_remove,
256 .driver = {
257 .name = "mtd-ram",
258 .owner = THIS_MODULE,
259 },
260 };
261
262 /* module init/exit */
263
platram_init(void)264 static int __init platram_init(void)
265 {
266 printk("Generic platform RAM MTD, (c) 2004 Simtec Electronics\n");
267 return platform_driver_register(&platram_driver);
268 }
269
platram_exit(void)270 static void __exit platram_exit(void)
271 {
272 platform_driver_unregister(&platram_driver);
273 }
274
275 module_init(platram_init);
276 module_exit(platram_exit);
277
278 MODULE_LICENSE("GPL");
279 MODULE_AUTHOR("Ben Dooks <ben@simtec.co.uk>");
280 MODULE_DESCRIPTION("MTD platform RAM map driver");
281