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/device.h>
   8 #include <linux/init.h>
   9 #include <linux/io.h>
  10 #include <linux/slab.h>
  11 #include <linux/sys_soc.h>
  12 #include <linux/platform_device.h>
  13 #include <linux/mfd/syscon.h>
  14 #include <linux/regmap.h>
  15 #include <linux/of.h>
  16
  17 /* System ID in syscon */
  18 #define REALVIEW_SYS_ID_OFFSET 0x00
  19
  20 static const struct of_device_id realview_soc_of_match[] = {
  21         { .compatible = "arm,realview-eb-soc",  },
  22         { .compatible = "arm,realview-pb1176-soc", },
  23         { .compatible = "arm,realview-pb11mp-soc", },
  24         { .compatible = "arm,realview-pba8-soc", },
  25         { .compatible = "arm,realview-pbx-soc", },
  26         { }
  27 };
  28
  29 static u32 realview_coreid;
  30
  31 static const char *realview_arch_str(u32 id)
  32 {
  33         switch ((id >> 8) & 0xf) {
  34         case 0x04:
  35                 return "AHB";
  36         case 0x05:
  37                 return "Multi-layer AXI";
  38         default:
  39                 return "Unknown";
  40         }
  41 }
  42
  43 static ssize_t
  44 manufacturer_show(struct device *dev, struct device_attribute *attr, char *buf)
  45 {
  46         return sprintf(buf, "%02x\n", realview_coreid >> 24);
  47 }
  48
  49 static DEVICE_ATTR_RO(manufacturer);
  50
  51 static ssize_t
  52 board_show(struct device *dev, struct device_attribute *attr, char *buf)
  53 {
  54         return sprintf(buf, "HBI-%03x\n", ((realview_coreid >> 16) & 0xfff));
  55 }
  56
  57 static DEVICE_ATTR_RO(board);
  58
  59 static ssize_t
  60 fpga_show(struct device *dev, struct device_attribute *attr, char *buf)
  61 {
  62         return sprintf(buf, "%s\n", realview_arch_str(realview_coreid));
  63 }
  64
  65 static DEVICE_ATTR_RO(fpga);
  66
  67 static ssize_t
  68 build_show(struct device *dev, struct device_attribute *attr, char *buf)
  69 {
  70         return sprintf(buf, "%02x\n", (realview_coreid & 0xFF));
  71 }
  72
  73 static DEVICE_ATTR_RO(build);
  74
  75 static struct attribute *realview_attrs[] = {
  76         &dev_attr_manufacturer.attr,
  77         &dev_attr_board.attr,
  78         &dev_attr_fpga.attr,
  79         &dev_attr_build.attr,
  80         NULL
  81 };
  82
  83 ATTRIBUTE_GROUPS(realview);
  84
  85 static void realview_soc_socdev_release(void *data)
  86 {
  87         struct soc_device *soc_dev = data;
  88
  89         soc_device_unregister(soc_dev);
  90 }
  91
  92 static int realview_soc_probe(struct platform_device *pdev)
  93 {
  94         struct regmap *syscon_regmap;
  95         struct soc_device *soc_dev;
  96         struct soc_device_attribute *soc_dev_attr;
  97         struct device_node *np = pdev->dev.of_node;
  98         int ret;
  99
 100         syscon_regmap = syscon_regmap_lookup_by_phandle(np, "regmap");
 101         if (IS_ERR(syscon_regmap))
 102                 return PTR_ERR(syscon_regmap);
 103
 104         soc_dev_attr = devm_kzalloc(&pdev->dev, sizeof(*soc_dev_attr), GFP_KERNEL);
 105         if (!soc_dev_attr)
 106                 return -ENOMEM;
 107
 108         ret = of_property_read_string(np, "compatible",
 109                                       &soc_dev_attr->soc_id);
 110         if (ret)
 111                 return -EINVAL;
 112
 113         soc_dev_attr->machine = "RealView";
 114         soc_dev_attr->family = "Versatile";
 115         soc_dev_attr->custom_attr_group = realview_groups[0];
 116         soc_dev = soc_device_register(soc_dev_attr);
 117         if (IS_ERR(soc_dev))
 118                 return -ENODEV;
 119
 120         ret = devm_add_action_or_reset(&pdev->dev, realview_soc_socdev_release,
 121                                        soc_dev);
 122         if (ret)
 123                 return ret;
 124
 125         ret = regmap_read(syscon_regmap, REALVIEW_SYS_ID_OFFSET,
 126                           &realview_coreid);
 127         if (ret)
 128                 return -ENODEV;
 129
 130         dev_info(&pdev->dev, "RealView Syscon Core ID: 0x%08x, HBI-%03x\n",
 131                  realview_coreid,
 132                  ((realview_coreid >> 16) & 0xfff));
 133         /* FIXME: add attributes for SoC to sysfs */
 134         return 0;
 135 }
 136
 137 static struct platform_driver realview_soc_driver = {
 138         .probe = realview_soc_probe,
 139         .driver = {
 140                 .name = "realview-soc",
 141                 .of_match_table = realview_soc_of_match,
 142         },
 143 };
 144 builtin_platform_driver(realview_soc_driver);