drivers/platform/chrome/chromeos_pstore.c

   1 /*
   2  *  chromeos_pstore.c - Driver to instantiate Chromebook ramoops device
   3  *
   4  *  Copyright (C) 2013 Google, Inc.
   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 as published by
   8  *  the Free Software Foundation, version 2 of the License.
   9  */
  10
  11 #include <linux/dmi.h>
  12 #include <linux/module.h>
  13 #include <linux/platform_device.h>
  14 #include <linux/pstore_ram.h>
  15
  16 static struct dmi_system_id chromeos_pstore_dmi_table[] __initdata = {
  17         {
  18                 /*
  19                  * Today all Chromebooks/boxes ship with Google_* as version and
  20                  * coreboot as bios vendor. No other systems with this
  21                  * combination are known to date.
  22                  */
  23                 .matches = {
  24                         DMI_MATCH(DMI_BIOS_VENDOR, "coreboot"),
  25                         DMI_MATCH(DMI_BIOS_VERSION, "Google_"),
  26                 },
  27         },
  28         {
  29                 /* x86-alex, the first Samsung Chromebook. */
  30                 .matches = {
  31                         DMI_MATCH(DMI_SYS_VENDOR, "SAMSUNG ELECTRONICS CO., LTD."),
  32                         DMI_MATCH(DMI_PRODUCT_NAME, "Alex"),
  33                 },
  34         },
  35         {
  36                 /* x86-mario, the Cr-48 pilot device from Google. */
  37                 .matches = {
  38                         DMI_MATCH(DMI_SYS_VENDOR, "IEC"),
  39                         DMI_MATCH(DMI_PRODUCT_NAME, "Mario"),
  40                 },
  41         },
  42         {
  43                 /* x86-zgb, the first Acer Chromebook. */
  44                 .matches = {
  45                         DMI_MATCH(DMI_SYS_VENDOR, "ACER"),
  46                         DMI_MATCH(DMI_PRODUCT_NAME, "ZGB"),
  47                 },
  48         },
  49         { }
  50 };
  51 MODULE_DEVICE_TABLE(dmi, chromeos_pstore_dmi_table);
  52
  53 /*
  54  * On x86 chromebooks/boxes, the firmware will keep the legacy VGA memory
  55  * range untouched across reboots, so we use that to store our pstore
  56  * contents for panic logs, etc.
  57  */
  58 static struct ramoops_platform_data chromeos_ramoops_data = {
  59         .mem_size       = 0x100000,
  60         .mem_address    = 0xf00000,
  61         .record_size    = 0x20000,
  62         .console_size   = 0x20000,
  63         .ftrace_size    = 0x20000,
  64         .dump_oops      = 1,
  65 };
  66
  67 static struct platform_device chromeos_ramoops = {
  68         .name = "ramoops",
  69         .dev = {
  70                 .platform_data = &chromeos_ramoops_data,
  71         },
  72 };
  73
  74 static int __init chromeos_pstore_init(void)
  75 {
  76         if (dmi_check_system(chromeos_pstore_dmi_table))
  77                 return platform_device_register(&chromeos_ramoops);
  78
  79         return -ENODEV;
  80 }
  81
  82 static void __exit chromeos_pstore_exit(void)
  83 {
  84         platform_device_unregister(&chromeos_ramoops);
  85 }
  86
  87 module_init(chromeos_pstore_init);
  88 module_exit(chromeos_pstore_exit);
  89
  90 MODULE_DESCRIPTION("Chrome OS pstore module");
  91 MODULE_LICENSE("GPL");