drivers/mtd/maps/walnut.c

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