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_arch_str(u32 id)
  35 {
  36         switch ((id >> 8) & 0xf) {
  37         case 0x04:
  38                 return "AHB";
  39         case 0x05:
  40                 return "Multi-layer AXI";
  41         default:
  42                 return "Unknown";
  43         }
  44 }
  45
  46 static ssize_t realview_get_manf(struct device *dev,
  47                               struct device_attribute *attr,
  48                               char *buf)
  49 {
  50         return sprintf(buf, "%02x\n", realview_coreid >> 24);
  51 }
  52
  53 static struct device_attribute realview_manf_attr =
  54         __ATTR(manufacturer,  S_IRUGO, realview_get_manf,  NULL);
  55
  56 static ssize_t realview_get_board(struct device *dev,
  57                               struct device_attribute *attr,
  58                               char *buf)
  59 {
  60         return sprintf(buf, "HBI-%03x\n", ((realview_coreid >> 16) & 0xfff));
  61 }
  62
  63 static struct device_attribute realview_board_attr =
  64         __ATTR(board,  S_IRUGO, realview_get_board,  NULL);
  65
  66 static ssize_t realview_get_arch(struct device *dev,
  67                               struct device_attribute *attr,
  68                               char *buf)
  69 {
  70         return sprintf(buf, "%s\n", realview_arch_str(realview_coreid));
  71 }
  72
  73 static struct device_attribute realview_arch_attr =
  74         __ATTR(fpga,  S_IRUGO, realview_get_arch,  NULL);
  75
  76 static ssize_t realview_get_build(struct device *dev,
  77                                struct device_attribute *attr,
  78                                char *buf)
  79 {
  80         return sprintf(buf, "%02x\n", (realview_coreid & 0xFF));
  81 }
  82
  83 static struct device_attribute realview_build_attr =
  84         __ATTR(build,  S_IRUGO, realview_get_build,  NULL);
  85
  86 static int realview_soc_probe(struct platform_device *pdev)
  87 {
  88         static struct regmap *syscon_regmap;
  89         struct soc_device *soc_dev;
  90         struct soc_device_attribute *soc_dev_attr;
  91         struct device_node *np = pdev->dev.of_node;
  92         int ret;
  93
  94         syscon_regmap = syscon_regmap_lookup_by_phandle(np, "regmap");
  95         if (IS_ERR(syscon_regmap))
  96                 return PTR_ERR(syscon_regmap);
  97
  98         soc_dev_attr = kzalloc(sizeof(*soc_dev_attr), GFP_KERNEL);
  99         if (!soc_dev_attr)
 100                 return -ENOMEM;
 101
 102         ret = of_property_read_string(np, "compatible",
 103                                       &soc_dev_attr->soc_id);
 104         if (ret)
 105                 return -EINVAL;
 106
 107         soc_dev_attr->machine = "RealView";
 108         soc_dev_attr->family = "Versatile";
 109         soc_dev = soc_device_register(soc_dev_attr);
 110         if (IS_ERR(soc_dev)) {
 111                 kfree(soc_dev_attr);
 112                 return -ENODEV;
 113         }
 114         ret = regmap_read(syscon_regmap, REALVIEW_SYS_ID_OFFSET,
 115                           &realview_coreid);
 116         if (ret)
 117                 return -ENODEV;
 118
 119         device_create_file(soc_device_to_device(soc_dev), &realview_manf_attr);
 120         device_create_file(soc_device_to_device(soc_dev), &realview_board_attr);
 121         device_create_file(soc_device_to_device(soc_dev), &realview_arch_attr);
 122         device_create_file(soc_device_to_device(soc_dev), &realview_build_attr);
 123
 124         dev_info(&pdev->dev, "RealView Syscon Core ID: 0x%08x, HBI-%03x\n",
 125                  realview_coreid,
 126                  ((realview_coreid >> 16) & 0xfff));
 127         /* FIXME: add attributes for SoC to sysfs */
 128         return 0;
 129 }
 130
 131 static struct platform_driver realview_soc_driver = {
 132         .probe = realview_soc_probe,
 133         .driver = {
 134                 .name = "realview-soc",
 135                 .of_match_table = realview_soc_of_match,
 136         },
 137 };
 138 builtin_platform_driver(realview_soc_driver);