LXR linux/arch/arm/mach-imx/cpu-imx5.c

   1/*
   2 * Copyright 2008-2010 Freescale Semiconductor, Inc. All Rights Reserved.
   3 *
   4 * The code contained herein is licensed under the GNU General Public
   5 * License. You may obtain a copy of the GNU General Public License
   6 * Version 2 or later at the following locations:
   7 *
   8 * http://www.opensource.org/licenses/gpl-license.html
   9 * http://www.gnu.org/copyleft/gpl.html
  10 *
  11 * This file contains the CPU initialization code.
  12 */
  13
  14#include <linux/types.h>
  15#include <linux/kernel.h>
  16#include <linux/init.h>
  17#include <linux/module.h>
  18#include <linux/io.h>
  19#include <linux/of.h>
  20#include <linux/of_address.h>
  21
  22#include "hardware.h"
  23#include "common.h"
  24
  25static int mx5_cpu_rev = -1;
  26
  27#define IIM_SREV 0x24
  28
  29static u32 imx5_read_srev_reg(const char *compat)
  30{
  31        void __iomem *iim_base;
  32        struct device_node *np;
  33        u32 srev;
  34
  35        np = of_find_compatible_node(NULL, NULL, compat);
  36        iim_base = of_iomap(np, 0);
  37        WARN_ON(!iim_base);
  38
  39        srev = readl(iim_base + IIM_SREV) & 0xff;
  40
  41        iounmap(iim_base);
  42
  43        return srev;
  44}
  45
  46static int get_mx51_srev(void)
  47{
  48        u32 rev = imx5_read_srev_reg("fsl,imx51-iim");
  49
  50        switch (rev) {
  51        case 0x0:
  52                return IMX_CHIP_REVISION_2_0;
  53        case 0x10:
  54                return IMX_CHIP_REVISION_3_0;
  55        default:
  56                return IMX_CHIP_REVISION_UNKNOWN;
  57        }
  58}
  59
  60/*
  61 * Returns:
  62 *      the silicon revision of the cpu
  63 */
  64int mx51_revision(void)
  65{
  66        if (mx5_cpu_rev == -1)
  67                mx5_cpu_rev = get_mx51_srev();
  68
  69        return mx5_cpu_rev;
  70}
  71EXPORT_SYMBOL(mx51_revision);
  72
  73#ifdef CONFIG_NEON
  74
  75/*
  76 * All versions of the silicon before Rev. 3 have broken NEON implementations.
  77 * Dependent on link order - so the assumption is that vfp_init is called
  78 * before us.
  79 */
  80int __init mx51_neon_fixup(void)
  81{
  82        if (mx51_revision() < IMX_CHIP_REVISION_3_0 &&
  83                        (elf_hwcap & HWCAP_NEON)) {
  84                elf_hwcap &= ~HWCAP_NEON;
  85                pr_info("Turning off NEON support, detected broken NEON implementation\n");
  86        }
  87        return 0;
  88}
  89
  90#endif
  91
  92static int get_mx53_srev(void)
  93{
  94        u32 rev = imx5_read_srev_reg("fsl,imx53-iim");
  95
  96        switch (rev) {
  97        case 0x0:
  98                return IMX_CHIP_REVISION_1_0;
  99        case 0x2:
 100                return IMX_CHIP_REVISION_2_0;
 101        case 0x3:
 102                return IMX_CHIP_REVISION_2_1;
 103        default:
 104                return IMX_CHIP_REVISION_UNKNOWN;
 105        }
 106}
 107
 108/*
 109 * Returns:
 110 *      the silicon revision of the cpu
 111 */
 112int mx53_revision(void)
 113{
 114        if (mx5_cpu_rev == -1)
 115                mx5_cpu_rev = get_mx53_srev();
 116
 117        return mx5_cpu_rev;
 118}
 119EXPORT_SYMBOL(mx53_revision);
 120