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 1.3 2005/03/19 22:41:27 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
  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         struct resource         *area;
  49         struct platdata_mtd_ram *pdata;
  50 };
  51
  52 /* to_platram_info()
  53  *
  54  * device private data to struct platram_info conversion
  55 */
  56
  57 static inline struct platram_info *to_platram_info(struct device *dev)
  58 {
  59         return (struct platram_info *)dev_get_drvdata(dev);
  60 }
  61
  62 /* platram_setrw
  63  *
  64  * call the platform device's set rw/ro control
  65  *
  66  * to = 0 => read-only
  67  *    = 1 => read-write
  68 */
  69
  70 static inline void platram_setrw(struct platram_info *info, int to)
  71 {
  72         if (info->pdata == NULL)
  73                 return;
  74
  75         if (info->pdata->set_rw != NULL)
  76                 (info->pdata->set_rw)(info->dev, to);
  77 }
  78
  79 /* platram_remove
  80  *
  81  * called to remove the device from the driver's control
  82 */
  83
  84 static int platram_remove(struct device *dev)
  85 {
  86         struct platram_info *info = to_platram_info(dev);
  87
  88         dev_set_drvdata(dev, NULL);
  89
  90         dev_dbg(dev, "removing device\n");
  91
  92         if (info == NULL)
  93                 return 0;
  94
  95         if (info->mtd) {
  96 #ifdef CONFIG_MTD_PARTITIONS
  97                 if (info->partitions) {
  98                         del_mtd_partitions(info->mtd);
  99                         kfree(info->partitions);
 100                 }
 101 #endif
 102                 del_mtd_device(info->mtd);
 103                 map_destroy(info->mtd);
 104         }
 105
 106         /* ensure ram is left read-only */
 107
 108         platram_setrw(info, PLATRAM_RO);
 109
 110         /* release resources */
 111
 112         if (info->area) {
 113                 release_resource(info->area);
 114                 kfree(info->area);
 115         }
 116
 117         if (info->map.virt != NULL)
 118                 iounmap(info->map.virt);
 119
 120         kfree(info);
 121
 122         return 0;
 123 }
 124
 125 /* platram_probe
 126  *
 127  * called from device drive system when a device matching our
 128  * driver is found.
 129 */
 130
 131 static int platram_probe(struct device *dev)
 132 {
 133         struct platform_device *pd = to_platform_device(dev);
 134         struct platdata_mtd_ram *pdata;
 135         struct platram_info *info;
 136         struct resource *res;
 137         int err = 0;
 138
 139         dev_dbg(dev, "probe entered\n");
 140
 141         if (dev->platform_data == NULL) {
 142                 dev_err(dev, "no platform data supplied\n");
 143                 err = -ENOENT;
 144                 goto exit_error;
 145         }
 146
 147         pdata = dev->platform_data;
 148
 149         info = kmalloc(sizeof(*info), GFP_KERNEL);
 150         if (info == NULL) {
 151                 dev_err(dev, "no memory for flash info\n");
 152                 err = -ENOMEM;
 153                 goto exit_error;
 154         }
 155
 156         memset(info, 0, sizeof(*info));
 157         dev_set_drvdata(dev, info);
 158
 159         info->dev = dev;
 160         info->pdata = pdata;
 161
 162         /* get the resource for the memory mapping */
 163
 164         res = platform_get_resource(pd, IORESOURCE_MEM, 0);
 165
 166         if (res == NULL) {
 167                 dev_err(dev, "no memory resource specified\n");
 168                 err = -ENOENT;
 169                 goto exit_free;
 170         }
 171
 172         dev_dbg(dev, "got platform resource %p (0x%lx)\n", res, res->start);
 173
 174         /* setup map parameters */
 175
 176         info->map.phys = res->start;
 177         info->map.size = (res->end - res->start) + 1;
 178         info->map.name = pdata->mapname != NULL ? pdata->mapname : pd->name;
 179         info->map.bankwidth = pdata->bankwidth;
 180
 181         /* register our usage of the memory area */
 182
 183         info->area = request_mem_region(res->start, info->map.size, pd->name);
 184         if (info->area == NULL) {
 185                 dev_err(dev, "failed to request memory region\n");
 186                 err = -EIO;
 187                 goto exit_free;
 188         }
 189
 190         /* remap the memory area */
 191
 192         info->map.virt = ioremap(res->start, info->map.size);
 193         dev_dbg(dev, "virt %p, %lu bytes\n", info->map.virt, info->map.size);
 194
 195         if (info->map.virt == NULL) {
 196                 dev_err(dev, "failed to ioremap() region\n");
 197                 err = -EIO;
 198                 goto exit_free;
 199         }
 200
 201         simple_map_init(&info->map);
 202
 203         dev_dbg(dev, "initialised map, probing for mtd\n");
 204
 205         /* probe for the right mtd map driver */
 206
 207         info->mtd = do_map_probe("map_ram" , &info->map);
 208         if (info->mtd == NULL) {
 209                 dev_err(dev, "failed to probe for map_ram\n");
 210                 err = -ENOMEM;
 211                 goto exit_free;
 212         }
 213
 214         info->mtd->owner = THIS_MODULE;
 215
 216         platram_setrw(info, PLATRAM_RW);
 217
 218         /* check to see if there are any available partitions, or wether
 219          * to add this device whole */
 220
 221 #ifdef CONFIG_MTD_PARTITIONS
 222         if (pdata->nr_partitions > 0) {
 223                 const char **probes = { NULL };
 224
 225                 if (pdata->probes)
 226                         probes = (const char **)pdata->probes;
 227
 228                 err = parse_mtd_partitions(info->mtd, probes,
 229                                            &info->partitions, 0);
 230                 if (err > 0) {
 231                         err = add_mtd_partitions(info->mtd, info->partitions,
 232                                                  err);
 233                 }
 234         }
 235 #endif /* CONFIG_MTD_PARTITIONS */
 236
 237         if (add_mtd_device(info->mtd)) {
 238                 dev_err(dev, "add_mtd_device() failed\n");
 239                 err = -ENOMEM;
 240         }
 241
 242         dev_info(dev, "registered mtd device\n");
 243         return err;
 244
 245  exit_free:
 246         platram_remove(dev);
 247  exit_error:
 248         return err;
 249 }
 250
 251 /* device driver info */
 252
 253 static struct device_driver platram_driver = {
 254         .name           = "mtd-ram",
 255         .bus            = &platform_bus_type,
 256         .probe          = platram_probe,
 257         .remove         = platram_remove,
 258 };
 259
 260 /* module init/exit */
 261
 262 static int __init platram_init(void)
 263 {
 264         printk("Generic platform RAM MTD, (c) 2004 Simtec Electronics\n");
 265         return driver_register(&platram_driver);
 266 }
 267
 268 static void __exit platram_exit(void)
 269 {
 270         driver_unregister(&platram_driver);
 271 }
 272
 273 module_init(platram_init);
 274 module_exit(platram_exit);
 275
 276 MODULE_LICENSE("GPL");
 277 MODULE_AUTHOR("Ben Dooks <ben@simtec.co.uk>");
 278 MODULE_DESCRIPTION("MTD platform RAM map driver");