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Linux/drivers/mtd/maps/plat-ram.c

  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->owner = THIS_MODULE;
214         info->mtd->dev.parent = &pdev->dev;
215 
216         platram_setrw(info, PLATRAM_RW);
217 
218         /* check to see if there are any available partitions, or whether
219          * to add this device whole */
220 
221         err = mtd_device_parse_register(info->mtd, pdata->probes, NULL,
222                                         pdata->partitions,
223                                         pdata->nr_partitions);
224         if (!err)
225                 dev_info(&pdev->dev, "registered mtd device\n");
226 
227         if (pdata->nr_partitions) {
228                 /* add the whole device. */
229                 err = mtd_device_register(info->mtd, NULL, 0);
230                 if (err) {
231                         dev_err(&pdev->dev,
232                                 "failed to register the entire device\n");
233                 }
234         }
235 
236         return err;
237 
238  exit_free:
239         platram_remove(pdev);
240  exit_error:
241         return err;
242 }
243 
244 /* device driver info */
245 
246 /* work with hotplug and coldplug */
247 MODULE_ALIAS("platform:mtd-ram");
248 
249 static struct platform_driver platram_driver = {
250         .probe          = platram_probe,
251         .remove         = platram_remove,
252         .driver         = {
253                 .name   = "mtd-ram",
254                 .owner  = THIS_MODULE,
255         },
256 };
257 
258 module_platform_driver(platram_driver);
259 
260 MODULE_LICENSE("GPL");
261 MODULE_AUTHOR("Ben Dooks <ben@simtec.co.uk>");
262 MODULE_DESCRIPTION("MTD platform RAM map driver");
263 

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