drivers/firmware/google/coreboot_table-of.c

   1 /*
   2  * coreboot_table-of.c
   3  *
   4  * Coreboot table access through open firmware.
   5  *
   6  * Copyright 2017 Google Inc.
   7  *
   8  * This program is free software; you can redistribute it and/or modify
   9  * it under the terms of the GNU General Public License v2.0 as published by
  10  * the Free Software Foundation.
  11  *
  12  * This program is distributed in the hope that it will be useful,
  13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15  * GNU General Public License for more details.
  16  */
  17
  18 #include <linux/device.h>
  19 #include <linux/io.h>
  20 #include <linux/module.h>
  21 #include <linux/of_address.h>
  22 #include <linux/of_platform.h>
  23 #include <linux/platform_device.h>
  24
  25 #include "coreboot_table.h"
  26
  27 static int coreboot_table_of_probe(struct platform_device *pdev)
  28 {
  29         struct device_node *fw_dn = pdev->dev.of_node;
  30         void __iomem *ptr;
  31
  32         ptr = of_iomap(fw_dn, 0);
  33         of_node_put(fw_dn);
  34         if (!ptr)
  35                 return -ENOMEM;
  36
  37         return coreboot_table_init(&pdev->dev, ptr);
  38 }
  39
  40 static int coreboot_table_of_remove(struct platform_device *pdev)
  41 {
  42         return coreboot_table_exit();
  43 }
  44
  45 static const struct of_device_id coreboot_of_match[] = {
  46         { .compatible = "coreboot" },
  47         {},
  48 };
  49
  50 static struct platform_driver coreboot_table_of_driver = {
  51         .probe = coreboot_table_of_probe,
  52         .remove = coreboot_table_of_remove,
  53         .driver = {
  54                 .name = "coreboot_table_of",
  55                 .of_match_table = coreboot_of_match,
  56         },
  57 };
  58
  59 static int __init platform_coreboot_table_of_init(void)
  60 {
  61         struct platform_device *pdev;
  62         struct device_node *of_node;
  63
  64         /* Limit device creation to the presence of /firmware/coreboot node */
  65         of_node = of_find_node_by_path("/firmware/coreboot");
  66         if (!of_node)
  67                 return -ENODEV;
  68
  69         if (!of_match_node(coreboot_of_match, of_node))
  70                 return -ENODEV;
  71
  72         pdev = of_platform_device_create(of_node, "coreboot_table_of", NULL);
  73         if (!pdev)
  74                 return -ENODEV;
  75
  76         return platform_driver_register(&coreboot_table_of_driver);
  77 }
  78
  79 module_init(platform_coreboot_table_of_init);
  80
  81 MODULE_AUTHOR("Google, Inc.");
  82 MODULE_LICENSE("GPL");