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 #include <linux/kdev_t.h>
  36 #include <linux/major.h>
  37 #include <linux/root_dev.h>
  38
  39 #include <linux/mtd/mtd.h>
  40 #include <linux/mtd/map.h>
  41 #include <linux/mtd/partitions.h>
  42 #include <linux/mtd/plat-ram.h>
  43
  44 #include <asm/io.h>
  45
  46 /* private structure for each mtd platform ram device created */
  47
  48 struct platram_info {
  49         struct device           *dev;
  50         struct mtd_info         *mtd;
  51         struct map_info          map;
  52         struct mtd_partition    *partitions;
  53         struct platdata_mtd_ram *pdata;
  54 };
  55
  56 /* to_platram_info()
  57  *
  58  * device private data to struct platram_info conversion
  59 */
  60
  61 static inline struct platram_info *to_platram_info(struct platform_device *dev)
  62 {
  63         return (struct platram_info *)platform_get_drvdata(dev);
  64 }
  65
  66 /* platram_setrw
  67  *
  68  * call the platform device's set rw/ro control
  69  *
  70  * to = 0 => read-only
  71  *    = 1 => read-write
  72 */
  73
  74 static inline void platram_setrw(struct platram_info *info, int to)
  75 {
  76         if (info->pdata == NULL)
  77                 return;
  78
  79         if (info->pdata->set_rw != NULL)
  80                 (info->pdata->set_rw)(info->dev, to);
  81 }
  82
  83 /* platram_remove
  84  *
  85  * called to remove the device from the driver's control
  86 */
  87
  88 static int platram_remove(struct platform_device *pdev)
  89 {
  90         struct platram_info *info = to_platram_info(pdev);
  91
  92         platform_set_drvdata(pdev, NULL);
  93
  94         dev_dbg(&pdev->dev, "removing device\n");
  95
  96         if (info == NULL)
  97                 return 0;
  98
  99         if (info->mtd) {
 100 #ifdef CONFIG_MTD_PARTITIONS
 101                 del_mtd_partitions(info->mtd);
 102                 if (info->partitions)
 103                         kfree(info->partitions);
 104 #endif
 105                 del_mtd_device(info->mtd);
 106                 map_destroy(info->mtd);
 107         }
 108
 109         /* ensure ram is left read-only */
 110
 111         platram_setrw(info, PLATRAM_RO);
 112
 113         /* release resources */
 114
 115         if (info->map.virt != NULL)
 116                 iounmap(info->map.virt);
 117
 118         kfree(info);
 119
 120         return 0;
 121 }
 122
 123 /* platram_probe
 124  *
 125  * called from device drive system when a device matching our
 126  * driver is found.
 127 */
 128
 129 static int platram_probe(struct platform_device *pdev)
 130 {
 131         struct platdata_mtd_ram *pdata;
 132         struct platram_info *info;
 133         struct resource *res;
 134         int err = 0;
 135
 136         dev_dbg(&pdev->dev, "probe entered\n");
 137
 138         if (pdev->dev.platform_data == NULL) {
 139                 dev_err(&pdev->dev, "no platform data supplied\n");
 140                 err = -ENOENT;
 141                 goto exit_error;
 142         }
 143
 144         pdata = pdev->dev.platform_data;
 145
 146         info = kmalloc(sizeof(*info), GFP_KERNEL);
 147         if (info == NULL) {
 148                 dev_err(&pdev->dev, "no memory for flash info\n");
 149                 err = -ENOMEM;
 150                 goto exit_error;
 151         }
 152
 153         memset(info, 0, sizeof(*info));
 154         platform_set_drvdata(pdev, info);
 155
 156         info->dev = &pdev->dev;
 157         info->pdata = pdata;
 158
 159         /* get the resource for the memory mapping */
 160
 161         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 162
 163         if (res == NULL) {
 164                 dev_err(&pdev->dev, "no memory resource specified\n");
 165                 err = -ENOENT;
 166                 goto exit_free;
 167         }
 168
 169         dev_dbg(&pdev->dev, "got platform resource %p (0x%lx)\n", res, res->start);
 170
 171         /* setup map parameters */
 172
 173         info->map.phys = res->start;
 174         info->map.size = (res->end - res->start) + 1;
 175         info->map.name = pdata->mapname != NULL ? pdata->mapname : (char *)pdev->name;
 176         info->map.bankwidth = pdata->bankwidth;
 177
 178         /* remap the memory area */
 179
 180         info->map.virt = ioremap(res->start, info->map.size);
 181         dev_dbg(&pdev->dev, "virt %p, %lu bytes\n", info->map.virt, info->map.size);
 182
 183         if (info->map.virt == NULL) {
 184                 dev_err(&pdev->dev, "failed to ioremap() region\n");
 185                 err = -EIO;
 186                 goto exit_free;
 187         }
 188
 189         simple_map_init(&info->map);
 190
 191         dev_dbg(&pdev->dev, "initialised map, probing for mtd\n");
 192
 193         /* probe for the right mtd map driver */
 194
 195         info->mtd = do_map_probe("map_ram" , &info->map);
 196         if (info->mtd == NULL) {
 197                 dev_err(&pdev->dev, "failed to probe for map_ram\n");
 198                 err = -ENOMEM;
 199                 goto exit_free;
 200         }
 201
 202         info->mtd->owner = THIS_MODULE;
 203
 204         platram_setrw(info, PLATRAM_RW);
 205
 206         /* check to see if there are any available partitions, or wether
 207          * to add this device whole */
 208
 209 #ifdef CONFIG_MTD_PARTITIONS
 210         if (pdata->nr_partitions > 0) {
 211                 err = add_mtd_partitions(info->mtd, pdata->partitions,
 212                                          pdata->nr_partitions);
 213                 if (err < 0)
 214                         goto exit_free;
 215         } else if (pdata->probes) {
 216                 err = parse_mtd_partitions(info->mtd, pdata->probes,
 217                                            &info->partitions, 0);
 218                 if (err > 0) {
 219                         err = add_mtd_partitions(info->mtd, info->partitions,
 220                                                  err);
 221                 }
 222                 if (err < 0)
 223                         goto exit_free;
 224         }
 225 #endif /* CONFIG_MTD_PARTITIONS */
 226
 227         if (add_mtd_device(info->mtd)) {
 228                 dev_err(&pdev->dev, "add_mtd_device() failed\n");
 229                 err = -ENOMEM;
 230                 goto exit_free;
 231         }
 232
 233         dev_info(&pdev->dev, "registered mtd device\n");
 234
 235         if (pdata->root_dev)
 236                 ROOT_DEV = MKDEV(MTD_BLOCK_MAJOR, info->mtd->index);
 237
 238         return 0;
 239
 240  exit_free:
 241         platram_remove(pdev);
 242  exit_error:
 243         return err;
 244 }
 245
 246 /* device driver info */
 247
 248 static struct platform_driver platram_driver = {
 249         .probe          = platram_probe,
 250         .remove         = platram_remove,
 251         .driver         = {
 252                 .name   = "mtd-ram",
 253                 .owner  = THIS_MODULE,
 254         },
 255 };
 256
 257 /* module init/exit */
 258
 259 static int __init platram_init(void)
 260 {
 261         printk("Generic platform RAM MTD, (c) 2004 Simtec Electronics\n");
 262         return platform_driver_register(&platram_driver);
 263 }
 264
 265 static void __exit platram_exit(void)
 266 {
 267         platform_driver_unregister(&platram_driver);
 268 }
 269
 270 module_init(platram_init);
 271 module_exit(platram_exit);
 272
 273 MODULE_LICENSE("GPL");
 274 MODULE_AUTHOR("Ben Dooks <ben@simtec.co.uk>");
 275 MODULE_DESCRIPTION("MTD platform RAM map driver");