drivers/soc/loongson/loongson2_guts.c

   1 // SPDX-License-Identifier: GPL-2.0+
   2 /*
   3  * Author: Yinbo Zhu <zhuyinbo@loongson.cn>
   4  * Copyright (C) 2022-2023 Loongson Technology Corporation Limited
   5  */
   6
   7 #include <linux/io.h>
   8 #include <linux/slab.h>
   9 #include <linux/module.h>
  10 #include <linux/of_fdt.h>
  11 #include <linux/sys_soc.h>
  12 #include <linux/of_address.h>
  13 #include <linux/platform_device.h>
  14
  15 static struct soc_device_attribute soc_dev_attr;
  16 static struct soc_device *soc_dev;
  17
  18 /*
  19  * Global Utility Registers.
  20  *
  21  * Not all registers defined in this structure are available on all chips, so
  22  * you are expected to know whether a given register actually exists on your
  23  * chip before you access it.
  24  *
  25  * Also, some registers are similar on different chips but have slightly
  26  * different names.  In these cases, one name is chosen to avoid extraneous
  27  * #ifdefs.
  28  */
  29 struct scfg_guts {
  30         u32     svr;            /* Version Register */
  31         u8      res0[4];
  32         u16     feature;        /* Feature Register */
  33         u32     vendor;         /* Vendor Register */
  34         u8      res1[6];
  35         u32     id;
  36         u8      res2[0x3ff8 - 0x18];
  37         u32     chip;
  38 };
  39
  40 static struct guts {
  41         struct scfg_guts __iomem *regs;
  42         bool little_endian;
  43 } *guts;
  44
  45 struct loongson2_soc_die_attr {
  46         char    *die;
  47         u32     svr;
  48         u32     mask;
  49 };
  50
  51 /* SoC die attribute definition for Loongson-2 platform */
  52 static const struct loongson2_soc_die_attr loongson2_soc_die[] = {
  53
  54         /*
  55          * LoongArch-based SoCs Loongson-2 Series
  56          */
  57
  58         /* Die: 2k1000, SoC: 2k1000 */
  59         { .die          = "2K1000",
  60           .svr          = 0x00000013,
  61           .mask         = 0x000000ff,
  62         },
  63         { },
  64 };
  65
  66 static const struct loongson2_soc_die_attr *loongson2_soc_die_match(
  67         u32 svr, const struct loongson2_soc_die_attr *matches)
  68 {
  69         while (matches->svr) {
  70                 if (matches->svr == (svr & matches->mask))
  71                         return matches;
  72                 matches++;
  73         }
  74
  75         return NULL;
  76 }
  77
  78 static u32 loongson2_guts_get_svr(void)
  79 {
  80         u32 svr = 0;
  81
  82         if (!guts || !guts->regs)
  83                 return svr;
  84
  85         if (guts->little_endian)
  86                 svr = ioread32(&guts->regs->svr);
  87         else
  88                 svr = ioread32be(&guts->regs->svr);
  89
  90         return svr;
  91 }
  92
  93 static int loongson2_guts_probe(struct platform_device *pdev)
  94 {
  95         struct device_node *root, *np = pdev->dev.of_node;
  96         struct device *dev = &pdev->dev;
  97         const struct loongson2_soc_die_attr *soc_die;
  98         const char *machine;
  99         u32 svr;
 100
 101         /* Initialize guts */
 102         guts = devm_kzalloc(dev, sizeof(*guts), GFP_KERNEL);
 103         if (!guts)
 104                 return -ENOMEM;
 105
 106         guts->little_endian = of_property_read_bool(np, "little-endian");
 107
 108         guts->regs = devm_platform_ioremap_resource(pdev, 0);
 109         if (IS_ERR(guts->regs))
 110                 return PTR_ERR(guts->regs);
 111
 112         /* Register soc device */
 113         root = of_find_node_by_path("/");
 114         if (of_property_read_string(root, "model", &machine))
 115                 of_property_read_string_index(root, "compatible", 0, &machine);
 116         of_node_put(root);
 117         if (machine)
 118                 soc_dev_attr.machine = devm_kstrdup(dev, machine, GFP_KERNEL);
 119
 120         svr = loongson2_guts_get_svr();
 121         soc_die = loongson2_soc_die_match(svr, loongson2_soc_die);
 122         if (soc_die) {
 123                 soc_dev_attr.family = devm_kasprintf(dev, GFP_KERNEL,
 124                                                      "Loongson %s", soc_die->die);
 125         } else {
 126                 soc_dev_attr.family = devm_kasprintf(dev, GFP_KERNEL, "Loongson");
 127         }
 128         if (!soc_dev_attr.family)
 129                 return -ENOMEM;
 130         soc_dev_attr.soc_id = devm_kasprintf(dev, GFP_KERNEL,
 131                                              "svr:0x%08x", svr);
 132         if (!soc_dev_attr.soc_id)
 133                 return -ENOMEM;
 134         soc_dev_attr.revision = devm_kasprintf(dev, GFP_KERNEL, "%d.%d",
 135                                                (svr >>  4) & 0xf, svr & 0xf);
 136         if (!soc_dev_attr.revision)
 137                 return -ENOMEM;
 138
 139         soc_dev = soc_device_register(&soc_dev_attr);
 140         if (IS_ERR(soc_dev))
 141                 return PTR_ERR(soc_dev);
 142
 143         pr_info("Machine: %s\n", soc_dev_attr.machine);
 144         pr_info("SoC family: %s\n", soc_dev_attr.family);
 145         pr_info("SoC ID: %s, Revision: %s\n",
 146                 soc_dev_attr.soc_id, soc_dev_attr.revision);
 147
 148         return 0;
 149 }
 150
 151 static int loongson2_guts_remove(struct platform_device *dev)
 152 {
 153         soc_device_unregister(soc_dev);
 154
 155         return 0;
 156 }
 157
 158 /*
 159  * Table for matching compatible strings, for device tree
 160  * guts node, for Loongson-2 SoCs.
 161  */
 162 static const struct of_device_id loongson2_guts_of_match[] = {
 163         { .compatible = "loongson,ls2k-chipid", },
 164         {}
 165 };
 166 MODULE_DEVICE_TABLE(of, loongson2_guts_of_match);
 167
 168 static struct platform_driver loongson2_guts_driver = {
 169         .driver = {
 170                 .name = "loongson2-guts",
 171                 .of_match_table = loongson2_guts_of_match,
 172         },
 173         .probe = loongson2_guts_probe,
 174         .remove = loongson2_guts_remove,
 175 };
 176
 177 static int __init loongson2_guts_init(void)
 178 {
 179         return platform_driver_register(&loongson2_guts_driver);
 180 }
 181 core_initcall(loongson2_guts_init);
 182
 183 static void __exit loongson2_guts_exit(void)
 184 {
 185         platform_driver_unregister(&loongson2_guts_driver);
 186 }
 187 module_exit(loongson2_guts_exit);
 188
 189 MODULE_DESCRIPTION("Loongson2 GUTS driver");
 190 MODULE_LICENSE("GPL");