drivers/soc/versatile/soc-realview.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * Copyright (C) 2014 Linaro Ltd.
   4  *
   5  * Author: Linus Walleij <linus.walleij@linaro.org>
   6  */
   7 #include <linux/init.h>
   8 #include <linux/io.h>
   9 #include <linux/slab.h>
  10 #include <linux/sys_soc.h>
  11 #include <linux/platform_device.h>
  12 #include <linux/mfd/syscon.h>
  13 #include <linux/regmap.h>
  14 #include <linux/of.h>
  15
  16 /* System ID in syscon */
  17 #define REALVIEW_SYS_ID_OFFSET 0x00
  18
  19 static const struct of_device_id realview_soc_of_match[] = {
  20         { .compatible = "arm,realview-eb-soc",  },
  21         { .compatible = "arm,realview-pb1176-soc", },
  22         { .compatible = "arm,realview-pb11mp-soc", },
  23         { .compatible = "arm,realview-pba8-soc", },
  24         { .compatible = "arm,realview-pbx-soc", },
  25         { }
  26 };
  27
  28 static u32 realview_coreid;
  29
  30 static const char *realview_arch_str(u32 id)
  31 {
  32         switch ((id >> 8) & 0xf) {
  33         case 0x04:
  34                 return "AHB";
  35         case 0x05:
  36                 return "Multi-layer AXI";
  37         default:
  38                 return "Unknown";
  39         }
  40 }
  41
  42 static ssize_t
  43 manufacturer_show(struct device *dev, struct device_attribute *attr, char *buf)
  44 {
  45         return sprintf(buf, "%02x\n", realview_coreid >> 24);
  46 }
  47
  48 static DEVICE_ATTR_RO(manufacturer);
  49
  50 static ssize_t
  51 board_show(struct device *dev, struct device_attribute *attr, char *buf)
  52 {
  53         return sprintf(buf, "HBI-%03x\n", ((realview_coreid >> 16) & 0xfff));
  54 }
  55
  56 static DEVICE_ATTR_RO(board);
  57
  58 static ssize_t
  59 fpga_show(struct device *dev, struct device_attribute *attr, char *buf)
  60 {
  61         return sprintf(buf, "%s\n", realview_arch_str(realview_coreid));
  62 }
  63
  64 static DEVICE_ATTR_RO(fpga);
  65
  66 static ssize_t
  67 build_show(struct device *dev, struct device_attribute *attr, char *buf)
  68 {
  69         return sprintf(buf, "%02x\n", (realview_coreid & 0xFF));
  70 }
  71
  72 static DEVICE_ATTR_RO(build);
  73
  74 static struct attribute *realview_attrs[] = {
  75         &dev_attr_manufacturer.attr,
  76         &dev_attr_board.attr,
  77         &dev_attr_fpga.attr,
  78         &dev_attr_build.attr,
  79         NULL
  80 };
  81
  82 ATTRIBUTE_GROUPS(realview);
  83
  84 static int realview_soc_probe(struct platform_device *pdev)
  85 {
  86         struct regmap *syscon_regmap;
  87         struct soc_device *soc_dev;
  88         struct soc_device_attribute *soc_dev_attr;
  89         struct device_node *np = pdev->dev.of_node;
  90         int ret;
  91
  92         syscon_regmap = syscon_regmap_lookup_by_phandle(np, "regmap");
  93         if (IS_ERR(syscon_regmap))
  94                 return PTR_ERR(syscon_regmap);
  95
  96         soc_dev_attr = kzalloc(sizeof(*soc_dev_attr), GFP_KERNEL);
  97         if (!soc_dev_attr)
  98                 return -ENOMEM;
  99
 100         ret = of_property_read_string(np, "compatible",
 101                                       &soc_dev_attr->soc_id);
 102         if (ret)
 103                 return -EINVAL;
 104
 105         soc_dev_attr->machine = "RealView";
 106         soc_dev_attr->family = "Versatile";
 107         soc_dev_attr->custom_attr_group = realview_groups[0];
 108         soc_dev = soc_device_register(soc_dev_attr);
 109         if (IS_ERR(soc_dev)) {
 110                 kfree(soc_dev_attr);
 111                 return -ENODEV;
 112         }
 113         ret = regmap_read(syscon_regmap, REALVIEW_SYS_ID_OFFSET,
 114                           &realview_coreid);
 115         if (ret)
 116                 return -ENODEV;
 117
 118         dev_info(&pdev->dev, "RealView Syscon Core ID: 0x%08x, HBI-%03x\n",
 119                  realview_coreid,
 120                  ((realview_coreid >> 16) & 0xfff));
 121         /* FIXME: add attributes for SoC to sysfs */
 122         return 0;
 123 }
 124
 125 static struct platform_driver realview_soc_driver = {
 126         .probe = realview_soc_probe,
 127         .driver = {
 128                 .name = "realview-soc",
 129                 .of_match_table = realview_soc_of_match,
 130         },
 131 };
 132 builtin_platform_driver(realview_soc_driver);