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/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 mtd_partition    *partitions;
  48         bool                    free_partitions;
  49         struct resource         *area;
  50         struct platdata_mtd_ram *pdata;
  51 };
  52
  53 /* to_platram_info()
  54  *
  55  * device private data to struct platram_info conversion
  56 */
  57
  58 static inline struct platram_info *to_platram_info(struct platform_device *dev)
  59 {
  60         return (struct platram_info *)platform_get_drvdata(dev);
  61 }
  62
  63 /* platram_setrw
  64  *
  65  * call the platform device's set rw/ro control
  66  *
  67  * to = 0 => read-only
  68  *    = 1 => read-write
  69 */
  70
  71 static inline void platram_setrw(struct platram_info *info, int to)
  72 {
  73         if (info->pdata == NULL)
  74                 return;
  75
  76         if (info->pdata->set_rw != NULL)
  77                 (info->pdata->set_rw)(info->dev, to);
  78 }
  79
  80 /* platram_remove
  81  *
  82  * called to remove the device from the driver's control
  83 */
  84
  85 static int platram_remove(struct platform_device *pdev)
  86 {
  87         struct platram_info *info = to_platram_info(pdev);
  88
  89         platform_set_drvdata(pdev, NULL);
  90
  91         dev_dbg(&pdev->dev, "removing device\n");
  92
  93         if (info == NULL)
  94                 return 0;
  95
  96         if (info->mtd) {
  97 #ifdef CONFIG_MTD_PARTITIONS
  98                 if (info->partitions) {
  99                         del_mtd_partitions(info->mtd);
 100                         if (info->free_partitions)
 101                                 kfree(info->partitions);
 102                 }
 103 #endif
 104                 del_mtd_device(info->mtd);
 105                 map_destroy(info->mtd);
 106         }
 107
 108         /* ensure ram is left read-only */
 109
 110         platram_setrw(info, PLATRAM_RO);
 111
 112         /* release resources */
 113
 114         if (info->area) {
 115                 release_resource(info->area);
 116                 kfree(info->area);
 117         }
 118
 119         if (info->map.virt != NULL)
 120                 iounmap(info->map.virt);
 121
 122         kfree(info);
 123
 124         return 0;
 125 }
 126
 127 /* platram_probe
 128  *
 129  * called from device drive system when a device matching our
 130  * driver is found.
 131 */
 132
 133 static int platram_probe(struct platform_device *pdev)
 134 {
 135         struct platdata_mtd_ram *pdata;
 136         struct platram_info *info;
 137         struct resource *res;
 138         int err = 0;
 139
 140         dev_dbg(&pdev->dev, "probe entered\n");
 141
 142         if (pdev->dev.platform_data == NULL) {
 143                 dev_err(&pdev->dev, "no platform data supplied\n");
 144                 err = -ENOENT;
 145                 goto exit_error;
 146         }
 147
 148         pdata = pdev->dev.platform_data;
 149
 150         info = kzalloc(sizeof(*info), GFP_KERNEL);
 151         if (info == NULL) {
 152                 dev_err(&pdev->dev, "no memory for flash info\n");
 153                 err = -ENOMEM;
 154                 goto exit_error;
 155         }
 156
 157         platform_set_drvdata(pdev, info);
 158
 159         info->dev = &pdev->dev;
 160         info->pdata = pdata;
 161
 162         /* get the resource for the memory mapping */
 163
 164         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 165
 166         if (res == NULL) {
 167                 dev_err(&pdev->dev, "no memory resource specified\n");
 168                 err = -ENOENT;
 169                 goto exit_free;
 170         }
 171
 172         dev_dbg(&pdev->dev, "got platform resource %p (0x%llx)\n", res,
 173                 (unsigned long long)res->start);
 174
 175         /* setup map parameters */
 176
 177         info->map.phys = res->start;
 178         info->map.size = resource_size(res);
 179         info->map.name = pdata->mapname != NULL ?
 180                         (char *)pdata->mapname : (char *)pdev->name;
 181         info->map.bankwidth = pdata->bankwidth;
 182
 183         /* register our usage of the memory area */
 184
 185         info->area = request_mem_region(res->start, info->map.size, pdev->name);
 186         if (info->area == NULL) {
 187                 dev_err(&pdev->dev, "failed to request memory region\n");
 188                 err = -EIO;
 189                 goto exit_free;
 190         }
 191
 192         /* remap the memory area */
 193
 194         info->map.virt = ioremap(res->start, info->map.size);
 195         dev_dbg(&pdev->dev, "virt %p, %lu bytes\n", info->map.virt, info->map.size);
 196
 197         if (info->map.virt == NULL) {
 198                 dev_err(&pdev->dev, "failed to ioremap() region\n");
 199                 err = -EIO;
 200                 goto exit_free;
 201         }
 202
 203         simple_map_init(&info->map);
 204
 205         dev_dbg(&pdev->dev, "initialised map, probing for mtd\n");
 206
 207         /* probe for the right mtd map driver
 208          * supplied by the platform_data struct */
 209
 210         if (pdata->map_probes) {
 211                 const char **map_probes = pdata->map_probes;
 212
 213                 for ( ; !info->mtd && *map_probes; map_probes++)
 214                         info->mtd = do_map_probe(*map_probes , &info->map);
 215         }
 216         /* fallback to map_ram */
 217         else
 218                 info->mtd = do_map_probe("map_ram", &info->map);
 219
 220         if (info->mtd == NULL) {
 221                 dev_err(&pdev->dev, "failed to probe for map_ram\n");
 222                 err = -ENOMEM;
 223                 goto exit_free;
 224         }
 225
 226         info->mtd->owner = THIS_MODULE;
 227         info->mtd->dev.parent = &pdev->dev;
 228
 229         platram_setrw(info, PLATRAM_RW);
 230
 231         /* check to see if there are any available partitions, or wether
 232          * to add this device whole */
 233
 234 #ifdef CONFIG_MTD_PARTITIONS
 235         if (!pdata->nr_partitions) {
 236                 /* try to probe using the supplied probe type */
 237                 if (pdata->probes) {
 238                         err = parse_mtd_partitions(info->mtd, pdata->probes,
 239                                            &info->partitions, 0);
 240                         info->free_partitions = 1;
 241                         if (err > 0)
 242                                 err = add_mtd_partitions(info->mtd,
 243                                         info->partitions, err);
 244                 }
 245         }
 246         /* use the static mapping */
 247         else
 248                 err = add_mtd_partitions(info->mtd, pdata->partitions,
 249                                 pdata->nr_partitions);
 250 #endif /* CONFIG_MTD_PARTITIONS */
 251
 252         if (add_mtd_device(info->mtd)) {
 253                 dev_err(&pdev->dev, "add_mtd_device() failed\n");
 254                 err = -ENOMEM;
 255         }
 256
 257         if (!err)
 258                 dev_info(&pdev->dev, "registered mtd device\n");
 259
 260         return err;
 261
 262  exit_free:
 263         platram_remove(pdev);
 264  exit_error:
 265         return err;
 266 }
 267
 268 /* device driver info */
 269
 270 /* work with hotplug and coldplug */
 271 MODULE_ALIAS("platform:mtd-ram");
 272
 273 static struct platform_driver platram_driver = {
 274         .probe          = platram_probe,
 275         .remove         = platram_remove,
 276         .driver         = {
 277                 .name   = "mtd-ram",
 278                 .owner  = THIS_MODULE,
 279         },
 280 };
 281
 282 /* module init/exit */
 283
 284 static int __init platram_init(void)
 285 {
 286         printk("Generic platform RAM MTD, (c) 2004 Simtec Electronics\n");
 287         return platform_driver_register(&platram_driver);
 288 }
 289
 290 static void __exit platram_exit(void)
 291 {
 292         platform_driver_unregister(&platram_driver);
 293 }
 294
 295 module_init(platram_init);
 296 module_exit(platram_exit);
 297
 298 MODULE_LICENSE("GPL");
 299 MODULE_AUTHOR("Ben Dooks <ben@simtec.co.uk>");
 300 MODULE_DESCRIPTION("MTD platform RAM map driver");