drivers/mtd/maps/walnut.c

   1 /*
   2  * $Id: walnut.c,v 1.3 2005/11/07 11:14:29 gleixner Exp $
   3  *
   4  * Mapping for Walnut flash
   5  * (used ebony.c as a "framework")
   6  *
   7  * Heikki Lindholm <holindho@infradead.org>
   8  *
   9  *
  10  * This program is free software; you can redistribute  it and/or modify it
  11  * under  the terms of  the GNU General  Public License as published by the
  12  * Free Software Foundation;  either version 2 of the  License, or (at your
  13  * option) any later version.
  14  */
  15
  16 #include <linux/module.h>
  17 #include <linux/types.h>
  18 #include <linux/kernel.h>
  19 #include <linux/init.h>
  20 #include <linux/mtd/mtd.h>
  21 #include <linux/mtd/map.h>
  22 #include <linux/mtd/partitions.h>
  23 #include <linux/config.h>
  24 #include <asm/io.h>
  25 #include <asm/ibm4xx.h>
  26 #include <platforms/4xx/walnut.h>
  27
  28 /* these should be in platforms/4xx/walnut.h ? */
  29 #define WALNUT_FLASH_ONBD_N(x)          (x & 0x02)
  30 #define WALNUT_FLASH_SRAM_SEL(x)        (x & 0x01)
  31 #define WALNUT_FLASH_LOW                0xFFF00000
  32 #define WALNUT_FLASH_HIGH               0xFFF80000
  33 #define WALNUT_FLASH_SIZE               0x80000
  34
  35 static struct mtd_info *flash;
  36
  37 static struct map_info walnut_map = {
  38         .name =         "Walnut flash",
  39         .size =         WALNUT_FLASH_SIZE,
  40         .bankwidth =    1,
  41 };
  42
  43 /* Actually, OpenBIOS is the last 128 KiB of the flash - better
  44  * partitioning could be made */
  45 static struct mtd_partition walnut_partitions[] = {
  46         {
  47                 .name =   "OpenBIOS",
  48                 .offset = 0x0,
  49                 .size =   WALNUT_FLASH_SIZE,
  50                 /*.mask_flags = MTD_WRITEABLE, */ /* force read-only */
  51         }
  52 };
  53
  54 int __init init_walnut(void)
  55 {
  56         u8 fpga_brds1;
  57         void *fpga_brds1_adr;
  58         void *fpga_status_adr;
  59         unsigned long flash_base;
  60
  61         /* this should already be mapped (platform/4xx/walnut.c) */
  62         fpga_status_adr = ioremap(WALNUT_FPGA_BASE, 8);
  63         if (!fpga_status_adr)
  64                 return -ENOMEM;
  65
  66         fpga_brds1_adr = fpga_status_adr+5;
  67         fpga_brds1 = readb(fpga_brds1_adr);
  68         /* iounmap(fpga_status_adr); */
  69
  70         if (WALNUT_FLASH_ONBD_N(fpga_brds1)) {
  71                 printk("The on-board flash is disabled (U79 sw 5)!");
  72                 return -EIO;
  73         }
  74         if (WALNUT_FLASH_SRAM_SEL(fpga_brds1))
  75                 flash_base = WALNUT_FLASH_LOW;
  76         else
  77                 flash_base = WALNUT_FLASH_HIGH;
  78
  79         walnut_map.phys = flash_base;
  80         walnut_map.virt =
  81                 (void __iomem *)ioremap(flash_base, walnut_map.size);
  82
  83         if (!walnut_map.virt) {
  84                 printk("Failed to ioremap flash.\n");
  85                 return -EIO;
  86         }
  87
  88         simple_map_init(&walnut_map);
  89
  90         flash = do_map_probe("jedec_probe", &walnut_map);
  91         if (flash) {
  92                 flash->owner = THIS_MODULE;
  93                 add_mtd_partitions(flash, walnut_partitions,
  94                                         ARRAY_SIZE(walnut_partitions));
  95         } else {
  96                 printk("map probe failed for flash\n");
  97                 return -ENXIO;
  98         }
  99
 100         return 0;
 101 }
 102
 103 static void __exit cleanup_walnut(void)
 104 {
 105         if (flash) {
 106                 del_mtd_partitions(flash);
 107                 map_destroy(flash);
 108         }
 109
 110         if (walnut_map.virt) {
 111                 iounmap((void *)walnut_map.virt);
 112                 walnut_map.virt = 0;
 113         }
 114 }
 115
 116 module_init(init_walnut);
 117 module_exit(cleanup_walnut);
 118
 119 MODULE_LICENSE("GPL");
 120 MODULE_AUTHOR("Heikki Lindholm <holindho@infradead.org>");
 121 MODULE_DESCRIPTION("MTD map and partitions for IBM 405GP Walnut boards");