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/version.h>
  14 #include <linux/ioport.h>
  15
  16 #include <lantiq_soc.h>
  17
  18 /* all access to the ebu must be locked */
  19 DEFINE_SPINLOCK(ebu_lock);
  20 EXPORT_SYMBOL_GPL(ebu_lock);
  21
  22 static struct resource ltq_ebu_resource = {
  23         .name   = "ebu",
  24         .start  = LTQ_EBU_BASE_ADDR,
  25         .end    = LTQ_EBU_BASE_ADDR + LTQ_EBU_SIZE - 1,
  26         .flags  = IORESOURCE_MEM,
  27 };
  28
  29 /* remapped base addr of the clock unit and external bus unit */
  30 void __iomem *ltq_ebu_membase;
  31
  32 static int __init lantiq_ebu_init(void)
  33 {
  34         /* insert and request the memory region */
  35         if (insert_resource(&iomem_resource, &ltq_ebu_resource) < 0)
  36                 panic("Failed to insert ebu memory\n");
  37
  38         if (request_mem_region(ltq_ebu_resource.start,
  39                         resource_size(&ltq_ebu_resource), "ebu") < 0)
  40                 panic("Failed to request ebu memory\n");
  41
  42         /* remap ebu register range */
  43         ltq_ebu_membase = ioremap_nocache(ltq_ebu_resource.start,
  44                                 resource_size(&ltq_ebu_resource));
  45         if (!ltq_ebu_membase)
  46                 panic("Failed to remap ebu memory\n");
  47
  48         /* make sure to unprotect the memory region where flash is located */
  49         ltq_ebu_w32(ltq_ebu_r32(LTQ_EBU_BUSCON0) & ~EBU_WRDIS, LTQ_EBU_BUSCON0);
  50         return 0;
  51 }
  52
  53 postcore_initcall(lantiq_ebu_init);