arch/mips/lantiq/xway/ebu.c

   1 /*
   2  *  This program is free software; you can redistribute it and/or modify it
   3  *  under the terms of the GNU General Public License version 2 as published
   4  *  by the Free Software Foundation.
   5  *
   6  *  EBU - the external bus unit attaches PCI, NOR and NAND
   7  *
   8  *  Copyright (C) 2010 John Crispin <blogic@openwrt.org>
   9  */
  10
  11 #include <linux/kernel.h>
  12 #include <linux/module.h>
  13 #include <linux/ioport.h>
  14
  15 #include <lantiq_soc.h>
  16
  17 /* all access to the ebu must be locked */
  18 DEFINE_SPINLOCK(ebu_lock);
  19 EXPORT_SYMBOL_GPL(ebu_lock);
  20
  21 static struct resource ltq_ebu_resource = {
  22         .name   = "ebu",
  23         .start  = LTQ_EBU_BASE_ADDR,
  24         .end    = LTQ_EBU_BASE_ADDR + LTQ_EBU_SIZE - 1,
  25         .flags  = IORESOURCE_MEM,
  26 };
  27
  28 /* remapped base addr of the clock unit and external bus unit */
  29 void __iomem *ltq_ebu_membase;
  30
  31 static int __init lantiq_ebu_init(void)
  32 {
  33         /* insert and request the memory region */
  34         if (insert_resource(&iomem_resource, &ltq_ebu_resource) < 0)
  35                 panic("Failed to insert ebu memory");
  36
  37         if (request_mem_region(ltq_ebu_resource.start,
  38                         resource_size(&ltq_ebu_resource), "ebu") < 0)
  39                 panic("Failed to request ebu memory");
  40
  41         /* remap ebu register range */
  42         ltq_ebu_membase = ioremap_nocache(ltq_ebu_resource.start,
  43                                 resource_size(&ltq_ebu_resource));
  44         if (!ltq_ebu_membase)
  45                 panic("Failed to remap ebu memory");
  46
  47         /* make sure to unprotect the memory region where flash is located */
  48         ltq_ebu_w32(ltq_ebu_r32(LTQ_EBU_BUSCON0) & ~EBU_WRDIS, LTQ_EBU_BUSCON0);
  49         return 0;
  50 }
  51
  52 postcore_initcall(lantiq_ebu_init);