arch/arm/mach-imx/cache-l2x0.c

   1 /*
   2  * Copyright (C) 2009-2010 Pengutronix
   3  * Sascha Hauer <s.hauer@pengutronix.de>
   4  * Juergen Beisert <j.beisert@pengutronix.de>
   5  *
   6  * This program is free software; you can redistribute it and/or modify it under
   7  * the terms of the GNU General Public License version 2 as published by the
   8  * Free Software Foundation.
   9  */
  10
  11 #include <linux/init.h>
  12 #include <linux/err.h>
  13 #include <linux/kernel.h>
  14
  15 #include <asm/hardware/cache-l2x0.h>
  16
  17 #include <mach/hardware.h>
  18
  19 static int mxc_init_l2x0(void)
  20 {
  21         void __iomem *l2x0_base;
  22         void __iomem *clkctl_base;
  23
  24         if (!cpu_is_mx31() && !cpu_is_mx35())
  25                 return 0;
  26
  27 /*
  28  * First of all, we must repair broken chip settings. There are some
  29  * i.MX35 CPUs in the wild, comming with bogus L2 cache settings. These
  30  * misconfigured CPUs will run amok immediately when the L2 cache gets enabled.
  31  * Workaraound is to setup the correct register setting prior enabling the
  32  * L2 cache. This should not hurt already working CPUs, as they are using the
  33  * same value.
  34  */
  35 #define L2_MEM_VAL 0x10
  36
  37         clkctl_base = ioremap(MX35_CLKCTL_BASE_ADDR, 4096);
  38         if (clkctl_base != NULL) {
  39                 writel(0x00000515, clkctl_base + L2_MEM_VAL);
  40                 iounmap(clkctl_base);
  41         } else {
  42                 pr_err("L2 cache: Cannot fix timing. Trying to continue without\n");
  43         }
  44
  45         l2x0_base = ioremap(MX3x_L2CC_BASE_ADDR, 4096);
  46         if (IS_ERR(l2x0_base)) {
  47                 printk(KERN_ERR "remapping L2 cache area failed with %ld\n",
  48                                 PTR_ERR(l2x0_base));
  49                 return 0;
  50         }
  51
  52         l2x0_init(l2x0_base, 0x00030024, 0x00000000);
  53
  54         return 0;
  55 }
  56 early_initcall(mxc_init_l2x0);