linux/drivers/mtd/maps/plat-ram.c
<<
>>
Prefs
   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/kernel.h>
  27#include <linux/string.h>
  28#include <linux/ioport.h>
  29#include <linux/device.h>
  30#include <linux/slab.h>
  31#include <linux/platform_device.h>
  32
  33#include <linux/mtd/mtd.h>
  34#include <linux/mtd/map.h>
  35#include <linux/mtd/partitions.h>
  36#include <linux/mtd/plat-ram.h>
  37
  38#include <asm/io.h>
  39
  40/* private structure for each mtd platform ram device created */
  41
  42struct platram_info {
  43        struct device           *dev;
  44        struct mtd_info         *mtd;
  45        struct map_info          map;
  46        struct resource         *area;
  47        struct platdata_mtd_ram *pdata;
  48};
  49
  50/* to_platram_info()
  51 *
  52 * device private data to struct platram_info conversion
  53*/
  54
  55static inline struct platram_info *to_platram_info(struct platform_device *dev)
  56{
  57        return platform_get_drvdata(dev);
  58}
  59
  60/* platram_setrw
  61 *
  62 * call the platform device's set rw/ro control
  63 *
  64 * to = 0 => read-only
  65 *    = 1 => read-write
  66*/
  67
  68static inline void platram_setrw(struct platram_info *info, int to)
  69{
  70        if (info->pdata == NULL)
  71                return;
  72
  73        if (info->pdata->set_rw != NULL)
  74                (info->pdata->set_rw)(info->dev, to);
  75}
  76
  77/* platram_remove
  78 *
  79 * called to remove the device from the driver's control
  80*/
  81
  82static int platram_remove(struct platform_device *pdev)
  83{
  84        struct platram_info *info = to_platram_info(pdev);
  85
  86        dev_dbg(&pdev->dev, "removing device\n");
  87
  88        if (info == NULL)
  89                return 0;
  90
  91        if (info->mtd) {
  92                mtd_device_unregister(info->mtd);
  93                map_destroy(info->mtd);
  94        }
  95
  96        /* ensure ram is left read-only */
  97
  98        platram_setrw(info, PLATRAM_RO);
  99
 100        /* release resources */
 101
 102        if (info->area) {
 103                release_resource(info->area);
 104                kfree(info->area);
 105        }
 106
 107        if (info->map.virt != NULL)
 108                iounmap(info->map.virt);
 109
 110        kfree(info);
 111
 112        return 0;
 113}
 114
 115/* platram_probe
 116 *
 117 * called from device drive system when a device matching our
 118 * driver is found.
 119*/
 120
 121static int platram_probe(struct platform_device *pdev)
 122{
 123        struct platdata_mtd_ram *pdata;
 124        struct platram_info *info;
 125        struct resource *res;
 126        int err = 0;
 127
 128        dev_dbg(&pdev->dev, "probe entered\n");
 129
 130        if (dev_get_platdata(&pdev->dev) == NULL) {
 131                dev_err(&pdev->dev, "no platform data supplied\n");
 132                err = -ENOENT;
 133                goto exit_error;
 134        }
 135
 136        pdata = dev_get_platdata(&pdev->dev);
 137
 138        info = kzalloc(sizeof(*info), GFP_KERNEL);
 139        if (info == NULL) {
 140                err = -ENOMEM;
 141                goto exit_error;
 142        }
 143
 144        platform_set_drvdata(pdev, info);
 145
 146        info->dev = &pdev->dev;
 147        info->pdata = pdata;
 148
 149        /* get the resource for the memory mapping */
 150
 151        res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 152
 153        if (res == NULL) {
 154                dev_err(&pdev->dev, "no memory resource specified\n");
 155                err = -ENOENT;
 156                goto exit_free;
 157        }
 158
 159        dev_dbg(&pdev->dev, "got platform resource %p (0x%llx)\n", res,
 160                (unsigned long long)res->start);
 161
 162        /* setup map parameters */
 163
 164        info->map.phys = res->start;
 165        info->map.size = resource_size(res);
 166        info->map.name = pdata->mapname != NULL ?
 167                        (char *)pdata->mapname : (char *)pdev->name;
 168        info->map.bankwidth = pdata->bankwidth;
 169
 170        /* register our usage of the memory area */
 171
 172        info->area = request_mem_region(res->start, info->map.size, pdev->name);
 173        if (info->area == NULL) {
 174                dev_err(&pdev->dev, "failed to request memory region\n");
 175                err = -EIO;
 176                goto exit_free;
 177        }
 178
 179        /* remap the memory area */
 180
 181        info->map.virt = ioremap(res->start, info->map.size);
 182        dev_dbg(&pdev->dev, "virt %p, %lu bytes\n", info->map.virt, info->map.size);
 183
 184        if (info->map.virt == NULL) {
 185                dev_err(&pdev->dev, "failed to ioremap() region\n");
 186                err = -EIO;
 187                goto exit_free;
 188        }
 189
 190        simple_map_init(&info->map);
 191
 192        dev_dbg(&pdev->dev, "initialised map, probing for mtd\n");
 193
 194        /* probe for the right mtd map driver
 195         * supplied by the platform_data struct */
 196
 197        if (pdata->map_probes) {
 198                const char * const *map_probes = pdata->map_probes;
 199
 200                for ( ; !info->mtd && *map_probes; map_probes++)
 201                        info->mtd = do_map_probe(*map_probes , &info->map);
 202        }
 203        /* fallback to map_ram */
 204        else
 205                info->mtd = do_map_probe("map_ram", &info->map);
 206
 207        if (info->mtd == NULL) {
 208                dev_err(&pdev->dev, "failed to probe for map_ram\n");
 209                err = -ENOMEM;
 210                goto exit_free;
 211        }
 212
 213        info->mtd->owner = THIS_MODULE;
 214        info->mtd->dev.parent = &pdev->dev;
 215
 216        platram_setrw(info, PLATRAM_RW);
 217
 218        /* check to see if there are any available partitions, or whether
 219         * to add this device whole */
 220
 221        err = mtd_device_parse_register(info->mtd, pdata->probes, NULL,
 222                                        pdata->partitions,
 223                                        pdata->nr_partitions);
 224        if (!err)
 225                dev_info(&pdev->dev, "registered mtd device\n");
 226
 227        if (pdata->nr_partitions) {
 228                /* add the whole device. */
 229                err = mtd_device_register(info->mtd, NULL, 0);
 230                if (err) {
 231                        dev_err(&pdev->dev,
 232                                "failed to register the entire device\n");
 233                }
 234        }
 235
 236        return err;
 237
 238 exit_free:
 239        platram_remove(pdev);
 240 exit_error:
 241        return err;
 242}
 243
 244/* device driver info */
 245
 246/* work with hotplug and coldplug */
 247MODULE_ALIAS("platform:mtd-ram");
 248
 249static struct platform_driver platram_driver = {
 250        .probe          = platram_probe,
 251        .remove         = platram_remove,
 252        .driver         = {
 253                .name   = "mtd-ram",
 254        },
 255};
 256
 257module_platform_driver(platram_driver);
 258
 259MODULE_LICENSE("GPL");
 260MODULE_AUTHOR("Ben Dooks <ben@simtec.co.uk>");
 261MODULE_DESCRIPTION("MTD platform RAM map driver");
 262
lxr.linux.no kindly hosted by Redpill Linpro AS, provider of Linux consulting and operations services since 1995.