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 platfrom device based RAM map
   8  *
   9  * $Id: plat-ram.c,v 1.7 2005/11/07 11:14:28 gleixner Exp $
  10  *
  11  * This program is free software; you can redistribute it and/or modify
  12  * it under the terms of the GNU General Public License as published by
  13  * the Free Software Foundation; either version 2 of the License, or
  14  * (at your option) any later version.
  15  *
  16  * This program is distributed in the hope that it will be useful,
  17  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  18  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  19  * GNU General Public License for more details.
  20  *
  21  * You should have received a copy of the GNU General Public License
  22  * along with this program; if not, write to the Free Software
  23  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  24 */
  25
  26 #include <linux/module.h>
  27 #include <linux/types.h>
  28 #include <linux/init.h>
  29 #include <linux/kernel.h>
  30 #include <linux/string.h>
  31 #include <linux/ioport.h>
  32 #include <linux/device.h>
  33 #include <linux/slab.h>
  34 #include <linux/platform_device.h>
  35
  36 #include <linux/mtd/mtd.h>
  37 #include <linux/mtd/map.h>
  38 #include <linux/mtd/partitions.h>
  39 #include <linux/mtd/plat-ram.h>
  40
  41 #include <asm/io.h>
  42
  43 /* private structure for each mtd platform ram device created */
  44
  45 struct platram_info {
  46         struct device           *dev;
  47         struct mtd_info         *mtd;
  48         struct map_info          map;
  49         struct mtd_partition    *partitions;
  50         bool                    free_partitions;
  51         struct resource         *area;
  52         struct platdata_mtd_ram *pdata;
  53 };
  54
  55 /* to_platram_info()
  56  *
  57  * device private data to struct platram_info conversion
  58 */
  59
  60 static inline struct platram_info *to_platram_info(struct platform_device *dev)
  61 {
  62         return (struct platram_info *)platform_get_drvdata(dev);
  63 }
  64
  65 /* platram_setrw
  66  *
  67  * call the platform device's set rw/ro control
  68  *
  69  * to = 0 => read-only
  70  *    = 1 => read-write
  71 */
  72
  73 static inline void platram_setrw(struct platram_info *info, int to)
  74 {
  75         if (info->pdata == NULL)
  76                 return;
  77
  78         if (info->pdata->set_rw != NULL)
  79                 (info->pdata->set_rw)(info->dev, to);
  80 }
  81
  82 /* platram_remove
  83  *
  84  * called to remove the device from the driver's control
  85 */
  86
  87 static int platram_remove(struct platform_device *pdev)
  88 {
  89         struct platram_info *info = to_platram_info(pdev);
  90
  91         platform_set_drvdata(pdev, NULL);
  92
  93         dev_dbg(&pdev->dev, "removing device\n");
  94
  95         if (info == NULL)
  96                 return 0;
  97
  98         if (info->mtd) {
  99 #ifdef CONFIG_MTD_PARTITIONS
 100                 if (info->partitions) {
 101                         del_mtd_partitions(info->mtd);
 102                         if (info->free_partitions)
 103                                 kfree(info->partitions);
 104                 }
 105 #endif
 106                 del_mtd_device(info->mtd);
 107                 map_destroy(info->mtd);
 108         }
 109
 110         /* ensure ram is left read-only */
 111
 112         platram_setrw(info, PLATRAM_RO);
 113
 114         /* release resources */
 115
 116         if (info->area) {
 117                 release_resource(info->area);
 118                 kfree(info->area);
 119         }
 120
 121         if (info->map.virt != NULL)
 122                 iounmap(info->map.virt);
 123
 124         kfree(info);
 125
 126         return 0;
 127 }
 128
 129 /* platram_probe
 130  *
 131  * called from device drive system when a device matching our
 132  * driver is found.
 133 */
 134
 135 static int platram_probe(struct platform_device *pdev)
 136 {
 137         struct platdata_mtd_ram *pdata;
 138         struct platram_info *info;
 139         struct resource *res;
 140         int err = 0;
 141
 142         dev_dbg(&pdev->dev, "probe entered\n");
 143
 144         if (pdev->dev.platform_data == NULL) {
 145                 dev_err(&pdev->dev, "no platform data supplied\n");
 146                 err = -ENOENT;
 147                 goto exit_error;
 148         }
 149
 150         pdata = pdev->dev.platform_data;
 151
 152         info = kzalloc(sizeof(*info), GFP_KERNEL);
 153         if (info == NULL) {
 154                 dev_err(&pdev->dev, "no memory for flash info\n");
 155                 err = -ENOMEM;
 156                 goto exit_error;
 157         }
 158
 159         platform_set_drvdata(pdev, info);
 160
 161         info->dev = &pdev->dev;
 162         info->pdata = pdata;
 163
 164         /* get the resource for the memory mapping */
 165
 166         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 167
 168         if (res == NULL) {
 169                 dev_err(&pdev->dev, "no memory resource specified\n");
 170                 err = -ENOENT;
 171                 goto exit_free;
 172         }
 173
 174         dev_dbg(&pdev->dev, "got platform resource %p (0x%llx)\n", res,
 175                 (unsigned long long)res->start);
 176
 177         /* setup map parameters */
 178
 179         info->map.phys = res->start;
 180         info->map.size = (res->end - res->start) + 1;
 181         info->map.name = pdata->mapname != NULL ?
 182                         (char *)pdata->mapname : (char *)pdev->name;
 183         info->map.bankwidth = pdata->bankwidth;
 184
 185         /* register our usage of the memory area */
 186
 187         info->area = request_mem_region(res->start, info->map.size, pdev->name);
 188         if (info->area == NULL) {
 189                 dev_err(&pdev->dev, "failed to request memory region\n");
 190                 err = -EIO;
 191                 goto exit_free;
 192         }
 193
 194         /* remap the memory area */
 195
 196         info->map.virt = ioremap(res->start, info->map.size);
 197         dev_dbg(&pdev->dev, "virt %p, %lu bytes\n", info->map.virt, info->map.size);
 198
 199         if (info->map.virt == NULL) {
 200                 dev_err(&pdev->dev, "failed to ioremap() region\n");
 201                 err = -EIO;
 202                 goto exit_free;
 203         }
 204
 205         simple_map_init(&info->map);
 206
 207         dev_dbg(&pdev->dev, "initialised map, probing for mtd\n");
 208
 209         /* probe for the right mtd map driver
 210          * supplied by the platform_data struct */
 211
 212         if (pdata->map_probes) {
 213                 const char **map_probes = pdata->map_probes;
 214
 215                 for ( ; !info->mtd && *map_probes; map_probes++)
 216                         info->mtd = do_map_probe(*map_probes , &info->map);
 217         }
 218         /* fallback to map_ram */
 219         else
 220                 info->mtd = do_map_probe("map_ram", &info->map);
 221
 222         if (info->mtd == NULL) {
 223                 dev_err(&pdev->dev, "failed to probe for map_ram\n");
 224                 err = -ENOMEM;
 225                 goto exit_free;
 226         }
 227
 228         info->mtd->owner = THIS_MODULE;
 229
 230         platram_setrw(info, PLATRAM_RW);
 231
 232         /* check to see if there are any available partitions, or wether
 233          * to add this device whole */
 234
 235 #ifdef CONFIG_MTD_PARTITIONS
 236         if (!pdata->nr_partitions) {
 237                 /* try to probe using the supplied probe type */
 238                 if (pdata->probes) {
 239                         err = parse_mtd_partitions(info->mtd, pdata->probes,
 240                                            &info->partitions, 0);
 241                         info->free_partitions = 1;
 242                         if (err > 0)
 243                                 err = add_mtd_partitions(info->mtd,
 244                                         info->partitions, err);
 245                 }
 246         }
 247         /* use the static mapping */
 248         else
 249                 err = add_mtd_partitions(info->mtd, pdata->partitions,
 250                                 pdata->nr_partitions);
 251 #endif /* CONFIG_MTD_PARTITIONS */
 252
 253         if (add_mtd_device(info->mtd)) {
 254                 dev_err(&pdev->dev, "add_mtd_device() failed\n");
 255                 err = -ENOMEM;
 256         }
 257
 258         if (!err)
 259                 dev_info(&pdev->dev, "registered mtd device\n");
 260
 261         return err;
 262
 263  exit_free:
 264         platram_remove(pdev);
 265  exit_error:
 266         return err;
 267 }
 268
 269 /* device driver info */
 270
 271 /* work with hotplug and coldplug */
 272 MODULE_ALIAS("platform:mtd-ram");
 273
 274 static struct platform_driver platram_driver = {
 275         .probe          = platram_probe,
 276         .remove         = platram_remove,
 277         .driver         = {
 278                 .name   = "mtd-ram",
 279                 .owner  = THIS_MODULE,
 280         },
 281 };
 282
 283 /* module init/exit */
 284
 285 static int __init platram_init(void)
 286 {
 287         printk("Generic platform RAM MTD, (c) 2004 Simtec Electronics\n");
 288         return platform_driver_register(&platram_driver);
 289 }
 290
 291 static void __exit platram_exit(void)
 292 {
 293         platform_driver_unregister(&platram_driver);
 294 }
 295
 296 module_init(platram_init);
 297 module_exit(platram_exit);
 298
 299 MODULE_LICENSE("GPL");
 300 MODULE_AUTHOR("Ben Dooks <ben@simtec.co.uk>");
 301 MODULE_DESCRIPTION("MTD platform RAM map driver");