arch/arm/mach-mx5/cpu.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 <mach/hardware.h>
  19 #include <linux/io.h>
  20
  21 static int mx5_cpu_rev = -1;
  22
  23 #define IIM_SREV 0x24
  24 #define MX50_HW_ADADIG_DIGPROG  0xB0
  25
  26 static int get_mx51_srev(void)
  27 {
  28         void __iomem *iim_base = MX51_IO_ADDRESS(MX51_IIM_BASE_ADDR);
  29         u32 rev = readl(iim_base + IIM_SREV) & 0xff;
  30
  31         switch (rev) {
  32         case 0x0:
  33                 return IMX_CHIP_REVISION_2_0;
  34         case 0x10:
  35                 return IMX_CHIP_REVISION_3_0;
  36         default:
  37                 return IMX_CHIP_REVISION_UNKNOWN;
  38         }
  39 }
  40
  41 /*
  42  * Returns:
  43  *      the silicon revision of the cpu
  44  *      -EINVAL - not a mx51
  45  */
  46 int mx51_revision(void)
  47 {
  48         if (!cpu_is_mx51())
  49                 return -EINVAL;
  50
  51         if (mx5_cpu_rev == -1)
  52                 mx5_cpu_rev = get_mx51_srev();
  53
  54         return mx5_cpu_rev;
  55 }
  56 EXPORT_SYMBOL(mx51_revision);
  57
  58 #ifdef CONFIG_NEON
  59
  60 /*
  61  * All versions of the silicon before Rev. 3 have broken NEON implementations.
  62  * Dependent on link order - so the assumption is that vfp_init is called
  63  * before us.
  64  */
  65 static int __init mx51_neon_fixup(void)
  66 {
  67         if (!cpu_is_mx51())
  68                 return 0;
  69
  70         if (mx51_revision() < IMX_CHIP_REVISION_3_0 &&
  71                         (elf_hwcap & HWCAP_NEON)) {
  72                 elf_hwcap &= ~HWCAP_NEON;
  73                 pr_info("Turning off NEON support, detected broken NEON implementation\n");
  74         }
  75         return 0;
  76 }
  77
  78 late_initcall(mx51_neon_fixup);
  79 #endif
  80
  81 static int get_mx53_srev(void)
  82 {
  83         void __iomem *iim_base = MX51_IO_ADDRESS(MX53_IIM_BASE_ADDR);
  84         u32 rev = readl(iim_base + IIM_SREV) & 0xff;
  85
  86         switch (rev) {
  87         case 0x0:
  88                 return IMX_CHIP_REVISION_1_0;
  89         case 0x2:
  90                 return IMX_CHIP_REVISION_2_0;
  91         case 0x3:
  92                 return IMX_CHIP_REVISION_2_1;
  93         default:
  94                 return IMX_CHIP_REVISION_UNKNOWN;
  95         }
  96 }
  97
  98 /*
  99  * Returns:
 100  *      the silicon revision of the cpu
 101  *      -EINVAL - not a mx53
 102  */
 103 int mx53_revision(void)
 104 {
 105         if (!cpu_is_mx53())
 106                 return -EINVAL;
 107
 108         if (mx5_cpu_rev == -1)
 109                 mx5_cpu_rev = get_mx53_srev();
 110
 111         return mx5_cpu_rev;
 112 }
 113 EXPORT_SYMBOL(mx53_revision);
 114
 115 static int get_mx50_srev(void)
 116 {
 117         void __iomem *anatop = ioremap(MX50_ANATOP_BASE_ADDR, SZ_8K);
 118         u32 rev;
 119
 120         if (!anatop) {
 121                 mx5_cpu_rev = -EINVAL;
 122                 return 0;
 123         }
 124
 125         rev = readl(anatop + MX50_HW_ADADIG_DIGPROG);
 126         rev &= 0xff;
 127
 128         iounmap(anatop);
 129         if (rev == 0x0)
 130                 return IMX_CHIP_REVISION_1_0;
 131         else if (rev == 0x1)
 132                 return IMX_CHIP_REVISION_1_1;
 133         return 0;
 134 }
 135
 136 /*
 137  * Returns:
 138  *      the silicon revision of the cpu
 139  *      -EINVAL - not a mx50
 140  */
 141 int mx50_revision(void)
 142 {
 143         if (!cpu_is_mx50())
 144                 return -EINVAL;
 145
 146         if (mx5_cpu_rev == -1)
 147                 mx5_cpu_rev = get_mx50_srev();
 148
 149         return mx5_cpu_rev;
 150 }
 151 EXPORT_SYMBOL(mx50_revision);
 152
 153 static int __init post_cpu_init(void)
 154 {
 155         unsigned int reg;
 156         void __iomem *base;
 157
 158         if (cpu_is_mx51() || cpu_is_mx53()) {
 159                 if (cpu_is_mx51())
 160                         base = MX51_IO_ADDRESS(MX51_AIPS1_BASE_ADDR);
 161                 else
 162                         base = MX53_IO_ADDRESS(MX53_AIPS1_BASE_ADDR);
 163
 164                 __raw_writel(0x0, base + 0x40);
 165                 __raw_writel(0x0, base + 0x44);
 166                 __raw_writel(0x0, base + 0x48);
 167                 __raw_writel(0x0, base + 0x4C);
 168                 reg = __raw_readl(base + 0x50) & 0x00FFFFFF;
 169                 __raw_writel(reg, base + 0x50);
 170
 171                 if (cpu_is_mx51())
 172                         base = MX51_IO_ADDRESS(MX51_AIPS2_BASE_ADDR);
 173                 else
 174                         base = MX53_IO_ADDRESS(MX53_AIPS2_BASE_ADDR);
 175
 176                 __raw_writel(0x0, base + 0x40);
 177                 __raw_writel(0x0, base + 0x44);
 178                 __raw_writel(0x0, base + 0x48);
 179                 __raw_writel(0x0, base + 0x4C);
 180                 reg = __raw_readl(base + 0x50) & 0x00FFFFFF;
 181                 __raw_writel(reg, base + 0x50);
 182         }
 183
 184         return 0;
 185 }
 186
 187 postcore_initcall(post_cpu_init);