release/src-rt-6.x/linux/linux-2.6/drivers/mtd/maps/pmcmsp-ramroot.c

   1 /*
   2  * Mapping of the rootfs in a physical region of memory
   3  *
   4  * Copyright (C) 2005-2007 PMC-Sierra Inc.
   5  * Author: Andrew Hughes, Andrew_Hughes@pmc-sierra.com
   6  *
   7  *  This program is free software; you can redistribute  it and/or modify it
   8  *  under  the terms of  the GNU General  Public License as published by the
   9  *  Free Software Foundation;  either version 2 of the  License, or (at your
  10  *  option) any later version.
  11  *
  12  *  THIS  SOFTWARE  IS PROVIDED   ``AS  IS'' AND   ANY  EXPRESS OR IMPLIED
  13  *  WARRANTIES,   INCLUDING, BUT NOT  LIMITED  TO, THE IMPLIED WARRANTIES OF
  14  *  MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN
  15  *  NO  EVENT  SHALL   THE AUTHOR  BE    LIABLE FOR ANY   DIRECT, INDIRECT,
  16  *  INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  17  *  NOT LIMITED   TO, PROCUREMENT OF  SUBSTITUTE GOODS  OR SERVICES; LOSS OF
  18  *  USE, DATA,  OR PROFITS; OR  BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
  19  *  ANY THEORY OF LIABILITY, WHETHER IN  CONTRACT, STRICT LIABILITY, OR TORT
  20  *  (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
  21  *  THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  22  *
  23  *  You should have received a copy of the  GNU General Public License along
  24  *  with this program; if not, write  to the Free Software Foundation, Inc.,
  25  *  675 Mass Ave, Cambridge, MA 02139, USA.
  26  */
  27
  28 #include <linux/module.h>
  29 #include <linux/types.h>
  30 #include <linux/kernel.h>
  31 #include <linux/init.h>
  32 #include <linux/slab.h>
  33 #include <linux/fs.h>
  34 #include <linux/root_dev.h>
  35 #include <linux/mtd/mtd.h>
  36 #include <linux/mtd/map.h>
  37
  38 #include <asm/io.h>
  39
  40 #include <msp_prom.h>
  41
  42 static struct mtd_info *rr_mtd;
  43
  44 struct map_info rr_map = {
  45         .name = "ramroot",
  46         .bankwidth = 4,
  47 };
  48
  49 static int __init init_rrmap(void)
  50 {
  51         void *ramroot_start;
  52         unsigned long ramroot_size;
  53
  54         /* Check for supported rootfs types */
  55         if (get_ramroot(&ramroot_start, &ramroot_size)) {
  56                 rr_map.phys = CPHYSADDR(ramroot_start);
  57                 rr_map.size = ramroot_size;
  58
  59                 printk(KERN_NOTICE
  60                         "PMC embedded root device: 0x%08lx @ 0x%08lx\n",
  61                         rr_map.size, (unsigned long)rr_map.phys);
  62         } else {
  63                 printk(KERN_ERR
  64                         "init_rrmap: no supported embedded rootfs detected!\n");
  65                 return -ENXIO;
  66         }
  67
  68         /* Map rootfs to I/O space for block device driver */
  69         rr_map.virt = ioremap(rr_map.phys, rr_map.size);
  70         if (!rr_map.virt) {
  71                 printk(KERN_ERR "Failed to ioremap\n");
  72                 return -EIO;
  73         }
  74
  75         simple_map_init(&rr_map);
  76
  77         rr_mtd = do_map_probe("map_ram", &rr_map);
  78         if (rr_mtd) {
  79                 rr_mtd->owner = THIS_MODULE;
  80
  81                 add_mtd_device(rr_mtd);
  82                 ROOT_DEV = MKDEV(MTD_BLOCK_MAJOR, rr_mtd->index);
  83
  84                 return 0;
  85         }
  86
  87         iounmap(rr_map.virt);
  88         return -ENXIO;
  89 }
  90
  91 static void __exit cleanup_rrmap(void)
  92 {
  93         del_mtd_device(rr_mtd);
  94         map_destroy(rr_mtd);
  95
  96         iounmap(rr_map.virt);
  97         rr_map.virt = NULL;
  98 }
  99
 100 MODULE_AUTHOR("PMC-Sierra, Inc");
 101 MODULE_DESCRIPTION("MTD map driver for embedded PMC-Sierra MSP filesystem");
 102 MODULE_LICENSE("GPL");
 103
 104 module_init(init_rrmap);
 105 module_exit(cleanup_rrmap);