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 1.4 2005/10/10 00:51:26 bjd 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         struct resource         *area;
  51         struct platdata_mtd_ram *pdata;
  52 };
  53
  54 /* to_platram_info()
  55  *
  56  * device private data to struct platram_info conversion
  57 */
  58
  59 static inline struct platram_info *to_platram_info(struct device *dev)
  60 {
  61         return (struct platram_info *)dev_get_drvdata(dev);
  62 }
  63
  64 /* platram_setrw
  65  *
  66  * call the platform device's set rw/ro control
  67  *
  68  * to = 0 => read-only
  69  *    = 1 => read-write
  70 */
  71
  72 static inline void platram_setrw(struct platram_info *info, int to)
  73 {
  74         if (info->pdata == NULL)
  75                 return;
  76
  77         if (info->pdata->set_rw != NULL)
  78                 (info->pdata->set_rw)(info->dev, to);
  79 }
  80
  81 /* platram_remove
  82  *
  83  * called to remove the device from the driver's control
  84 */
  85
  86 static int platram_remove(struct device *dev)
  87 {
  88         struct platram_info *info = to_platram_info(dev);
  89
  90         dev_set_drvdata(dev, NULL);
  91
  92         dev_dbg(dev, "removing device\n");
  93
  94         if (info == NULL)
  95                 return 0;
  96
  97         if (info->mtd) {
  98 #ifdef CONFIG_MTD_PARTITIONS
  99                 if (info->partitions) {
 100                         del_mtd_partitions(info->mtd);
 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 device *dev)
 134 {
 135         struct platform_device *pd = to_platform_device(dev);
 136         struct platdata_mtd_ram *pdata;
 137         struct platram_info *info;
 138         struct resource *res;
 139         int err = 0;
 140
 141         dev_dbg(dev, "probe entered\n");
 142
 143         if (dev->platform_data == NULL) {
 144                 dev_err(dev, "no platform data supplied\n");
 145                 err = -ENOENT;
 146                 goto exit_error;
 147         }
 148
 149         pdata = dev->platform_data;
 150
 151         info = kmalloc(sizeof(*info), GFP_KERNEL);
 152         if (info == NULL) {
 153                 dev_err(dev, "no memory for flash info\n");
 154                 err = -ENOMEM;
 155                 goto exit_error;
 156         }
 157
 158         memset(info, 0, sizeof(*info));
 159         dev_set_drvdata(dev, info);
 160
 161         info->dev = dev;
 162         info->pdata = pdata;
 163
 164         /* get the resource for the memory mapping */
 165
 166         res = platform_get_resource(pd, IORESOURCE_MEM, 0);
 167
 168         if (res == NULL) {
 169                 dev_err(dev, "no memory resource specified\n");
 170                 err = -ENOENT;
 171                 goto exit_free;
 172         }
 173
 174         dev_dbg(dev, "got platform resource %p (0x%lx)\n", res, res->start);
 175
 176         /* setup map parameters */
 177
 178         info->map.phys = res->start;
 179         info->map.size = (res->end - res->start) + 1;
 180         info->map.name = pdata->mapname != NULL ? pdata->mapname : pd->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, pd->name);
 186         if (info->area == NULL) {
 187                 dev_err(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(dev, "virt %p, %lu bytes\n", info->map.virt, info->map.size);
 196
 197         if (info->map.virt == NULL) {
 198                 dev_err(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(dev, "initialised map, probing for mtd\n");
 206
 207         /* probe for the right mtd map driver */
 208
 209         info->mtd = do_map_probe("map_ram" , &info->map);
 210         if (info->mtd == NULL) {
 211                 dev_err(dev, "failed to probe for map_ram\n");
 212                 err = -ENOMEM;
 213                 goto exit_free;
 214         }
 215
 216         info->mtd->owner = THIS_MODULE;
 217
 218         platram_setrw(info, PLATRAM_RW);
 219
 220         /* check to see if there are any available partitions, or wether
 221          * to add this device whole */
 222
 223 #ifdef CONFIG_MTD_PARTITIONS
 224         if (pdata->nr_partitions > 0) {
 225                 const char **probes = { NULL };
 226
 227                 if (pdata->probes)
 228                         probes = (const char **)pdata->probes;
 229
 230                 err = parse_mtd_partitions(info->mtd, probes,
 231                                            &info->partitions, 0);
 232                 if (err > 0) {
 233                         err = add_mtd_partitions(info->mtd, info->partitions,
 234                                                  err);
 235                 }
 236         }
 237 #endif /* CONFIG_MTD_PARTITIONS */
 238
 239         if (add_mtd_device(info->mtd)) {
 240                 dev_err(dev, "add_mtd_device() failed\n");
 241                 err = -ENOMEM;
 242         }
 243
 244         dev_info(dev, "registered mtd device\n");
 245         return err;
 246
 247  exit_free:
 248         platram_remove(dev);
 249  exit_error:
 250         return err;
 251 }
 252
 253 /* device driver info */
 254
 255 static struct device_driver platram_driver = {
 256         .name           = "mtd-ram",
 257         .owner          = THIS_MODULE,
 258         .bus            = &platform_bus_type,
 259         .probe          = platram_probe,
 260         .remove         = platram_remove,
 261 };
 262
 263 /* module init/exit */
 264
 265 static int __init platram_init(void)
 266 {
 267         printk("Generic platform RAM MTD, (c) 2004 Simtec Electronics\n");
 268         return driver_register(&platram_driver);
 269 }
 270
 271 static void __exit platram_exit(void)
 272 {
 273         driver_unregister(&platram_driver);
 274 }
 275
 276 module_init(platram_init);
 277 module_exit(platram_exit);
 278
 279 MODULE_LICENSE("GPL");
 280 MODULE_AUTHOR("Ben Dooks <ben@simtec.co.uk>");
 281 MODULE_DESCRIPTION("MTD platform RAM map driver");