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 vendor and
  20                  * coreboot as bios vendor. No other systems with this
  21                  * combination are known to date.
  22                  */
  23                 .matches = {
  24                         DMI_MATCH(DMI_SYS_VENDOR, "GOOGLE"),
  25                         DMI_MATCH(DMI_BIOS_VENDOR, "coreboot"),
  26                 },
  27         },
  28         {
  29                 /*
  30                  * The first Samsung Chromebox and Chromebook Series 5 550 use
  31                  * coreboot but with Samsung as the system vendor.
  32                  */
  33                 .matches = {
  34                         DMI_MATCH(DMI_SYS_VENDOR, "SAMSUNG"),
  35                         DMI_MATCH(DMI_BIOS_VENDOR, "coreboot"),
  36                 },
  37         },
  38         {
  39                 /* x86-alex, the first Samsung Chromebook. */
  40                 .matches = {
  41                         DMI_MATCH(DMI_SYS_VENDOR, "SAMSUNG ELECTRONICS CO., LTD."),
  42                         DMI_MATCH(DMI_PRODUCT_NAME, "Alex"),
  43                 },
  44         },
  45         {
  46                 /* x86-mario, the Cr-48 pilot device from Google. */
  47                 .matches = {
  48                         DMI_MATCH(DMI_SYS_VENDOR, "IEC"),
  49                         DMI_MATCH(DMI_PRODUCT_NAME, "Mario"),
  50                 },
  51         },
  52         {
  53                 /* x86-zgb, the first Acer Chromebook. */
  54                 .matches = {
  55                         DMI_MATCH(DMI_SYS_VENDOR, "ACER"),
  56                         DMI_MATCH(DMI_PRODUCT_NAME, "ZGB"),
  57                 },
  58         },
  59         { }
  60 };
  61 MODULE_DEVICE_TABLE(dmi, chromeos_pstore_dmi_table);
  62
  63 /*
  64  * On x86 chromebooks/boxes, the firmware will keep the legacy VGA memory
  65  * range untouched across reboots, so we use that to store our pstore
  66  * contents for panic logs, etc.
  67  */
  68 static struct ramoops_platform_data chromeos_ramoops_data = {
  69         .mem_size       = 0x100000,
  70         .mem_address    = 0xf00000,
  71         .record_size    = 0x20000,
  72         .console_size   = 0x20000,
  73         .ftrace_size    = 0x20000,
  74         .dump_oops      = 1,
  75 };
  76
  77 static struct platform_device chromeos_ramoops = {
  78         .name = "ramoops",
  79         .dev = {
  80                 .platform_data = &chromeos_ramoops_data,
  81         },
  82 };
  83
  84 static int __init chromeos_pstore_init(void)
  85 {
  86         if (dmi_check_system(chromeos_pstore_dmi_table))
  87                 return platform_device_register(&chromeos_ramoops);
  88
  89         return -ENODEV;
  90 }
  91
  92 static void __exit chromeos_pstore_exit(void)
  93 {
  94         platform_device_unregister(&chromeos_ramoops);
  95 }
  96
  97 module_init(chromeos_pstore_init);
  98 module_exit(chromeos_pstore_exit);
  99
 100 MODULE_DESCRIPTION("Chrome OS pstore module");
 101 MODULE_LICENSE("GPL");