drivers/soc/versatile/soc-realview.c

   1 /*
   2  * Copyright (C) 2014 Linaro Ltd.
   3  *
   4  * Author: Linus Walleij <linus.walleij@linaro.org>
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License version 2, as
   8  * published by the Free Software Foundation.
   9  *
  10  */
  11 #include <linux/init.h>
  12 #include <linux/io.h>
  13 #include <linux/slab.h>
  14 #include <linux/sys_soc.h>
  15 #include <linux/platform_device.h>
  16 #include <linux/mfd/syscon.h>
  17 #include <linux/regmap.h>
  18 #include <linux/of.h>
  19
  20 /* System ID in syscon */
  21 #define REALVIEW_SYS_ID_OFFSET 0x00
  22
  23 static const struct of_device_id realview_soc_of_match[] = {
  24         { .compatible = "arm,realview-eb-soc",  },
  25         { .compatible = "arm,realview-pb1176-soc", },
  26         { .compatible = "arm,realview-pb11mp-soc", },
  27         { .compatible = "arm,realview-pba8-soc", },
  28         { .compatible = "arm,realview-pbx-soc", },
  29         { }
  30 };
  31
  32 static u32 realview_coreid;
  33
  34 static const char *realview_board_str(u32 id)
  35 {
  36         switch ((id >> 16) & 0xfff) {
  37         case 0x0147:
  38                 return "HBI-0147";
  39         default:
  40                 return "Unknown";
  41         }
  42 }
  43
  44 static const char *realview_arch_str(u32 id)
  45 {
  46         switch ((id >> 8) & 0xf) {
  47         case 0x05:
  48                 return "Multi-layer AXI";
  49         default:
  50                 return "Unknown";
  51         }
  52 }
  53
  54 static ssize_t realview_get_manf(struct device *dev,
  55                               struct device_attribute *attr,
  56                               char *buf)
  57 {
  58         return sprintf(buf, "%02x\n", realview_coreid >> 24);
  59 }
  60
  61 static struct device_attribute realview_manf_attr =
  62         __ATTR(manufacturer,  S_IRUGO, realview_get_manf,  NULL);
  63
  64 static ssize_t realview_get_board(struct device *dev,
  65                               struct device_attribute *attr,
  66                               char *buf)
  67 {
  68         return sprintf(buf, "%s\n", realview_board_str(realview_coreid));
  69 }
  70
  71 static struct device_attribute realview_board_attr =
  72         __ATTR(board,  S_IRUGO, realview_get_board,  NULL);
  73
  74 static ssize_t realview_get_arch(struct device *dev,
  75                               struct device_attribute *attr,
  76                               char *buf)
  77 {
  78         return sprintf(buf, "%s\n", realview_arch_str(realview_coreid));
  79 }
  80
  81 static struct device_attribute realview_arch_attr =
  82         __ATTR(fpga,  S_IRUGO, realview_get_arch,  NULL);
  83
  84 static ssize_t realview_get_build(struct device *dev,
  85                                struct device_attribute *attr,
  86                                char *buf)
  87 {
  88         return sprintf(buf, "%02x\n", (realview_coreid & 0xFF));
  89 }
  90
  91 static struct device_attribute realview_build_attr =
  92         __ATTR(build,  S_IRUGO, realview_get_build,  NULL);
  93
  94 static int realview_soc_probe(struct platform_device *pdev)
  95 {
  96         static struct regmap *syscon_regmap;
  97         struct soc_device *soc_dev;
  98         struct soc_device_attribute *soc_dev_attr;
  99         struct device_node *np = pdev->dev.of_node;
 100         int ret;
 101
 102         syscon_regmap = syscon_regmap_lookup_by_phandle(np, "regmap");
 103         if (IS_ERR(syscon_regmap))
 104                 return PTR_ERR(syscon_regmap);
 105
 106         soc_dev_attr = kzalloc(sizeof(*soc_dev_attr), GFP_KERNEL);
 107         if (!soc_dev_attr)
 108                 return -ENOMEM;
 109
 110         ret = of_property_read_string(np, "compatible",
 111                                       &soc_dev_attr->soc_id);
 112         if (ret)
 113                 return -EINVAL;
 114
 115         soc_dev_attr->machine = "RealView";
 116         soc_dev_attr->family = "Versatile";
 117         soc_dev = soc_device_register(soc_dev_attr);
 118         if (IS_ERR(soc_dev)) {
 119                 kfree(soc_dev_attr);
 120                 return -ENODEV;
 121         }
 122         ret = regmap_read(syscon_regmap, REALVIEW_SYS_ID_OFFSET,
 123                           &realview_coreid);
 124         if (ret)
 125                 return -ENODEV;
 126
 127         device_create_file(soc_device_to_device(soc_dev), &realview_manf_attr);
 128         device_create_file(soc_device_to_device(soc_dev), &realview_board_attr);
 129         device_create_file(soc_device_to_device(soc_dev), &realview_arch_attr);
 130         device_create_file(soc_device_to_device(soc_dev), &realview_build_attr);
 131
 132         dev_info(&pdev->dev, "RealView Syscon Core ID: 0x%08x\n",
 133                  realview_coreid);
 134         /* FIXME: add attributes for SoC to sysfs */
 135         return 0;
 136 }
 137
 138 static struct platform_driver realview_soc_driver = {
 139         .probe = realview_soc_probe,
 140         .driver = {
 141                 .name = "realview-soc",
 142                 .of_match_table = realview_soc_of_match,
 143         },
 144 };
 145 module_platform_driver(realview_soc_driver);