drivers/firmware/google/coreboot_table-acpi.c

   1 /*
   2  * coreboot_table-acpi.c
   3  *
   4  * Using ACPI to locate Coreboot table and provide coreboot table access.
   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/acpi.h>
  19 #include <linux/device.h>
  20 #include <linux/err.h>
  21 #include <linux/init.h>
  22 #include <linux/io.h>
  23 #include <linux/kernel.h>
  24 #include <linux/module.h>
  25 #include <linux/platform_device.h>
  26
  27 #include "coreboot_table.h"
  28
  29 static int coreboot_table_acpi_probe(struct platform_device *pdev)
  30 {
  31         phys_addr_t phyaddr;
  32         resource_size_t len;
  33         struct coreboot_table_header __iomem *header = NULL;
  34         struct resource *res;
  35         void __iomem *ptr = NULL;
  36
  37         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
  38         if (!res)
  39                 return -EINVAL;
  40
  41         len = resource_size(res);
  42         if (!res->start || !len)
  43                 return -EINVAL;
  44
  45         phyaddr = res->start;
  46         header = ioremap_cache(phyaddr, sizeof(*header));
  47         if (header == NULL)
  48                 return -ENOMEM;
  49
  50         ptr = ioremap_cache(phyaddr,
  51                             header->header_bytes + header->table_bytes);
  52         iounmap(header);
  53         if (!ptr)
  54                 return -ENOMEM;
  55
  56         return coreboot_table_init(ptr);
  57 }
  58
  59 static int coreboot_table_acpi_remove(struct platform_device *pdev)
  60 {
  61         return coreboot_table_exit();
  62 }
  63
  64 static const struct acpi_device_id cros_coreboot_acpi_match[] = {
  65         { "GOOGCB00", 0 },
  66         { "BOOT0000", 0 },
  67         { }
  68 };
  69 MODULE_DEVICE_TABLE(acpi, cros_coreboot_acpi_match);
  70
  71 static struct platform_driver coreboot_table_acpi_driver = {
  72         .probe = coreboot_table_acpi_probe,
  73         .remove = coreboot_table_acpi_remove,
  74         .driver = {
  75                 .name = "coreboot_table_acpi",
  76                 .acpi_match_table = ACPI_PTR(cros_coreboot_acpi_match),
  77         },
  78 };
  79
  80 static int __init coreboot_table_acpi_init(void)
  81 {
  82         return platform_driver_register(&coreboot_table_acpi_driver);
  83 }
  84
  85 module_init(coreboot_table_acpi_init);
  86
  87 MODULE_AUTHOR("Google, Inc.");
  88 MODULE_LICENSE("GPL");