LXR linux/drivers/platform/chrome/chromeos

   1// SPDX-License-Identifier: GPL-2.0
   2// Driver to instantiate Chromebook ramoops device.
   3//
   4// Copyright (C) 2013 Google, Inc.
   5
   6#include <linux/acpi.h>
   7#include <linux/dmi.h>
   8#include <linux/module.h>
   9#include <linux/platform_device.h>
  10#include <linux/pstore_ram.h>
  11
  12static const struct dmi_system_id chromeos_pstore_dmi_table[] __initconst = {
  13        {
  14                /*
  15                 * Today all Chromebooks/boxes ship with Google_* as version and
  16                 * coreboot as bios vendor. No other systems with this
  17                 * combination are known to date.
  18                 */
  19                .matches = {
  20                        DMI_MATCH(DMI_BIOS_VENDOR, "coreboot"),
  21                        DMI_MATCH(DMI_BIOS_VERSION, "Google_"),
  22                },
  23        },
  24        {
  25                /* x86-alex, the first Samsung Chromebook. */
  26                .matches = {
  27                        DMI_MATCH(DMI_SYS_VENDOR, "SAMSUNG ELECTRONICS CO., LTD."),
  28                        DMI_MATCH(DMI_PRODUCT_NAME, "Alex"),
  29                },
  30        },
  31        {
  32                /* x86-mario, the Cr-48 pilot device from Google. */
  33                .matches = {
  34                        DMI_MATCH(DMI_SYS_VENDOR, "IEC"),
  35                        DMI_MATCH(DMI_PRODUCT_NAME, "Mario"),
  36                },
  37        },
  38        {
  39                /* x86-zgb, the first Acer Chromebook. */
  40                .matches = {
  41                        DMI_MATCH(DMI_SYS_VENDOR, "ACER"),
  42                        DMI_MATCH(DMI_PRODUCT_NAME, "ZGB"),
  43                },
  44        },
  45        { }
  46};
  47MODULE_DEVICE_TABLE(dmi, chromeos_pstore_dmi_table);
  48
  49/*
  50 * On x86 chromebooks/boxes, the firmware will keep the legacy VGA memory
  51 * range untouched across reboots, so we use that to store our pstore
  52 * contents for panic logs, etc.
  53 */
  54static struct ramoops_platform_data chromeos_ramoops_data = {
  55        .mem_size       = 0x100000,
  56        .mem_address    = 0xf00000,
  57        .record_size    = 0x40000,
  58        .console_size   = 0x20000,
  59        .ftrace_size    = 0x20000,
  60        .dump_oops      = 1,
  61};
  62
  63static struct platform_device chromeos_ramoops = {
  64        .name = "ramoops",
  65        .dev = {
  66                .platform_data = &chromeos_ramoops_data,
  67        },
  68};
  69
  70#ifdef CONFIG_ACPI
  71static const struct acpi_device_id cros_ramoops_acpi_match[] = {
  72        { "GOOG9999", 0 },
  73        { }
  74};
  75MODULE_DEVICE_TABLE(acpi, cros_ramoops_acpi_match);
  76
  77static struct platform_driver chromeos_ramoops_acpi = {
  78        .driver         = {
  79                .name   = "chromeos_pstore",
  80                .acpi_match_table = ACPI_PTR(cros_ramoops_acpi_match),
  81        },
  82};
  83
  84static int __init chromeos_probe_acpi(struct platform_device *pdev)
  85{
  86        struct resource *res;
  87        resource_size_t len;
  88
  89        res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
  90        if (!res)
  91                return -ENOMEM;
  92
  93        len = resource_size(res);
  94        if (!res->start || !len)
  95                return -ENOMEM;
  96
  97        pr_info("chromeos ramoops using acpi device.\n");
  98
  99        chromeos_ramoops_data.mem_size = len;
 100        chromeos_ramoops_data.mem_address = res->start;
 101
 102        return 0;
 103}
 104
 105static bool __init chromeos_check_acpi(void)
 106{
 107        if (!platform_driver_probe(&chromeos_ramoops_acpi, chromeos_probe_acpi))
 108                return true;
 109        return false;
 110}
 111#else
 112static inline bool chromeos_check_acpi(void) { return false; }
 113#endif
 114
 115static int __init chromeos_pstore_init(void)
 116{
 117        bool acpi_dev_found;
 118
 119        /* First check ACPI for non-hardcoded values from firmware. */
 120        acpi_dev_found = chromeos_check_acpi();
 121
 122        if (acpi_dev_found || dmi_check_system(chromeos_pstore_dmi_table))
 123                return platform_device_register(&chromeos_ramoops);
 124
 125        return -ENODEV;
 126}
 127
 128static void __exit chromeos_pstore_exit(void)
 129{
 130        platform_device_unregister(&chromeos_ramoops);
 131}
 132
 133module_init(chromeos_pstore_init);
 134module_exit(chromeos_pstore_exit);
 135
 136MODULE_DESCRIPTION("ChromeOS pstore module");
 137MODULE_LICENSE("GPL v2");
 138