drivers/soc/tegra/fuse/tegra-apbmisc.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * Copyright (c) 2014, NVIDIA CORPORATION.  All rights reserved.
   4  */
   5
   6 #include <linux/kernel.h>
   7 #include <linux/of.h>
   8 #include <linux/of_address.h>
   9 #include <linux/io.h>
  10
  11 #include <soc/tegra/fuse.h>
  12 #include <soc/tegra/common.h>
  13
  14 #include "fuse.h"
  15
  16 #define FUSE_SKU_INFO   0x10
  17
  18 #define PMC_STRAPPING_OPT_A_RAM_CODE_SHIFT      4
  19 #define PMC_STRAPPING_OPT_A_RAM_CODE_MASK_LONG  \
  20         (0xf << PMC_STRAPPING_OPT_A_RAM_CODE_SHIFT)
  21 #define PMC_STRAPPING_OPT_A_RAM_CODE_MASK_SHORT \
  22         (0x3 << PMC_STRAPPING_OPT_A_RAM_CODE_SHIFT)
  23
  24 static bool long_ram_code;
  25 static u32 strapping;
  26 static u32 chipid;
  27
  28 u32 tegra_read_chipid(void)
  29 {
  30         WARN(!chipid, "Tegra ABP MISC not yet available\n");
  31
  32         return chipid;
  33 }
  34
  35 u8 tegra_get_chip_id(void)
  36 {
  37         return (tegra_read_chipid() >> 8) & 0xff;
  38 }
  39
  40 u32 tegra_read_straps(void)
  41 {
  42         WARN(!chipid, "Tegra ABP MISC not yet available\n");
  43
  44         return strapping;
  45 }
  46
  47 u32 tegra_read_ram_code(void)
  48 {
  49         u32 straps = tegra_read_straps();
  50
  51         if (long_ram_code)
  52                 straps &= PMC_STRAPPING_OPT_A_RAM_CODE_MASK_LONG;
  53         else
  54                 straps &= PMC_STRAPPING_OPT_A_RAM_CODE_MASK_SHORT;
  55
  56         return straps >> PMC_STRAPPING_OPT_A_RAM_CODE_SHIFT;
  57 }
  58
  59 static const struct of_device_id apbmisc_match[] __initconst = {
  60         { .compatible = "nvidia,tegra20-apbmisc", },
  61         { .compatible = "nvidia,tegra186-misc", },
  62         { .compatible = "nvidia,tegra194-misc", },
  63         {},
  64 };
  65
  66 void __init tegra_init_revision(void)
  67 {
  68         u32 id, chip_id, minor_rev;
  69         int rev;
  70
  71         id = tegra_read_chipid();
  72         chip_id = (id >> 8) & 0xff;
  73         minor_rev = (id >> 16) & 0xf;
  74
  75         switch (minor_rev) {
  76         case 1:
  77                 rev = TEGRA_REVISION_A01;
  78                 break;
  79         case 2:
  80                 rev = TEGRA_REVISION_A02;
  81                 break;
  82         case 3:
  83                 if (chip_id == TEGRA20 && (tegra_fuse_read_spare(18) ||
  84                                            tegra_fuse_read_spare(19)))
  85                         rev = TEGRA_REVISION_A03p;
  86                 else
  87                         rev = TEGRA_REVISION_A03;
  88                 break;
  89         case 4:
  90                 rev = TEGRA_REVISION_A04;
  91                 break;
  92         default:
  93                 rev = TEGRA_REVISION_UNKNOWN;
  94         }
  95
  96         tegra_sku_info.revision = rev;
  97
  98         tegra_sku_info.sku_id = tegra_fuse_read_early(FUSE_SKU_INFO);
  99 }
 100
 101 void __init tegra_init_apbmisc(void)
 102 {
 103         void __iomem *apbmisc_base, *strapping_base;
 104         struct resource apbmisc, straps;
 105         struct device_node *np;
 106
 107         np = of_find_matching_node(NULL, apbmisc_match);
 108         if (!np) {
 109                 /*
 110                  * Fall back to legacy initialization for 32-bit ARM only. All
 111                  * 64-bit ARM device tree files for Tegra are required to have
 112                  * an APBMISC node.
 113                  *
 114                  * This is for backwards-compatibility with old device trees
 115                  * that didn't contain an APBMISC node.
 116                  */
 117                 if (IS_ENABLED(CONFIG_ARM) && soc_is_tegra()) {
 118                         /* APBMISC registers (chip revision, ...) */
 119                         apbmisc.start = 0x70000800;
 120                         apbmisc.end = 0x70000863;
 121                         apbmisc.flags = IORESOURCE_MEM;
 122
 123                         /* strapping options */
 124                         if (of_machine_is_compatible("nvidia,tegra124")) {
 125                                 straps.start = 0x7000e864;
 126                                 straps.end = 0x7000e867;
 127                         } else {
 128                                 straps.start = 0x70000008;
 129                                 straps.end = 0x7000000b;
 130                         }
 131
 132                         straps.flags = IORESOURCE_MEM;
 133
 134                         pr_warn("Using APBMISC region %pR\n", &apbmisc);
 135                         pr_warn("Using strapping options registers %pR\n",
 136                                 &straps);
 137                 } else {
 138                         /*
 139                          * At this point we're not running on Tegra, so play
 140                          * nice with multi-platform kernels.
 141                          */
 142                         return;
 143                 }
 144         } else {
 145                 /*
 146                  * Extract information from the device tree if we've found a
 147                  * matching node.
 148                  */
 149                 if (of_address_to_resource(np, 0, &apbmisc) < 0) {
 150                         pr_err("failed to get APBMISC registers\n");
 151                         return;
 152                 }
 153
 154                 if (of_address_to_resource(np, 1, &straps) < 0) {
 155                         pr_err("failed to get strapping options registers\n");
 156                         return;
 157                 }
 158         }
 159
 160         apbmisc_base = ioremap(apbmisc.start, resource_size(&apbmisc));
 161         if (!apbmisc_base) {
 162                 pr_err("failed to map APBMISC registers\n");
 163         } else {
 164                 chipid = readl_relaxed(apbmisc_base + 4);
 165                 iounmap(apbmisc_base);
 166         }
 167
 168         strapping_base = ioremap(straps.start, resource_size(&straps));
 169         if (!strapping_base) {
 170                 pr_err("failed to map strapping options registers\n");
 171         } else {
 172                 strapping = readl_relaxed(strapping_base);
 173                 iounmap(strapping_base);
 174         }
 175
 176         long_ram_code = of_property_read_bool(np, "nvidia,long-ram-code");
 177 }