kernel/linux/drivers/mtd/maps/bcm963xx.c

   1 /*
   2  * A simple flash mapping code for BCM963xx board flash memory
   3  * It is simple because it only treats all the flash memory as ROM
   4  * It is used with chips/map_rom.c
   5  *
   6  *  Song Wang (songw@broadcom.com)
   7  */
   8
   9 #include <linux/module.h>
  10 #include <linux/types.h>
  11 #include <linux/kernel.h>
  12 #include <linux/init.h>
  13 #include <asm/io.h>
  14 #include <linux/mtd/mtd.h>
  15 #include <linux/mtd/map.h>
  16 #include <linux/config.h>
  17
  18 #include <board.h>
  19 #include <bcmTag.h>
  20 #define  VERSION        "1.0"
  21
  22 extern PFILE_TAG kerSysImageTagGet(void);
  23
  24 static struct mtd_info *mymtd;
  25
  26 static map_word brcm_physmap_read16(struct map_info *map, unsigned long ofs)
  27 {
  28         map_word val;
  29
  30         val.x[0] = __raw_readw(map->map_priv_1 + ofs);
  31
  32         return val;
  33 }
  34
  35 static void brcm_physmap_copy_from(struct map_info *map, void *to, unsigned long from, ssize_t len)
  36 {
  37         memcpy_fromio(to, map->map_priv_1 + from, len);
  38 }
  39
  40 static struct map_info brcm_physmap_map = {
  41         .name           = "Physically mapped flash",
  42         .bankwidth      = 2,
  43         .read           = brcm_physmap_read16,
  44         .copy_from      = brcm_physmap_copy_from
  45 };
  46
  47 static int __init init_brcm_physmap(void)
  48 {
  49         PFILE_TAG pTag = NULL;
  50         u_int32_t rootfs_addr, kernel_addr;
  51         FLASH_ADDR_INFO info;
  52
  53         printk("bcm963xx_mtd driver v%s\n", VERSION);
  54         kerSysFlashAddrInfoGet( &info );
  55
  56         /* Read the flash memory map from flash memory. */
  57         if (!(pTag = kerSysImageTagGet())) {
  58                 printk("Failed to read image tag from flash\n");
  59                 return -EIO;
  60         }
  61
  62         rootfs_addr = (u_int32_t) simple_strtoul(pTag->rootfsAddress, NULL, 10);
  63         kernel_addr = (u_int32_t) simple_strtoul(pTag->kernelAddress, NULL, 10);
  64
  65         brcm_physmap_map.size = kernel_addr - rootfs_addr;
  66         brcm_physmap_map.map_priv_1 = (unsigned long)rootfs_addr;
  67
  68         if (!brcm_physmap_map.map_priv_1) {
  69                 printk("Wrong rootfs starting address\n");
  70                 return -EIO;
  71         }
  72
  73         if (brcm_physmap_map.size <= 0) {
  74                 printk("Wrong rootfs size\n");
  75                 return -EIO;
  76         }
  77
  78         mymtd = do_map_probe("map_rom", &brcm_physmap_map);
  79         if (mymtd) {
  80                 mymtd->owner = THIS_MODULE;
  81                 add_mtd_device(mymtd);
  82
  83                 return 0;
  84         }
  85
  86         return -ENXIO;
  87 }
  88
  89 static void __exit cleanup_brcm_physmap(void)
  90 {
  91         if (mymtd) {
  92                 del_mtd_device(mymtd);
  93                 map_destroy(mymtd);
  94         }
  95         if (brcm_physmap_map.map_priv_1) {
  96                 brcm_physmap_map.map_priv_1 = 0;
  97         }
  98 }
  99
 100 module_init(init_brcm_physmap);
 101 module_exit(cleanup_brcm_physmap);
 102
 103
 104 MODULE_LICENSE("GPL");
 105 MODULE_AUTHOR("Song Wang songw@broadcom.com");
 106 MODULE_DESCRIPTION("Configurable MTD map driver for read-only root file system");