2 * chromeos_pstore.c - Driver to instantiate Chromebook ramoops device
4 * Copyright (C) 2013 Google, Inc.
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.
11 #include <linux/acpi.h>
12 #include <linux/dmi.h>
13 #include <linux/module.h>
14 #include <linux/platform_device.h>
15 #include <linux/pstore_ram.h>
17 static struct dmi_system_id chromeos_pstore_dmi_table[] __initdata = {
20 * Today all Chromebooks/boxes ship with Google_* as version and
21 * coreboot as bios vendor. No other systems with this
22 * combination are known to date.
25 DMI_MATCH(DMI_BIOS_VENDOR, "coreboot"),
26 DMI_MATCH(DMI_BIOS_VERSION, "Google_"),
30 /* x86-alex, the first Samsung Chromebook. */
32 DMI_MATCH(DMI_SYS_VENDOR, "SAMSUNG ELECTRONICS CO., LTD."),
33 DMI_MATCH(DMI_PRODUCT_NAME, "Alex"),
37 /* x86-mario, the Cr-48 pilot device from Google. */
39 DMI_MATCH(DMI_SYS_VENDOR, "IEC"),
40 DMI_MATCH(DMI_PRODUCT_NAME, "Mario"),
44 /* x86-zgb, the first Acer Chromebook. */
46 DMI_MATCH(DMI_SYS_VENDOR, "ACER"),
47 DMI_MATCH(DMI_PRODUCT_NAME, "ZGB"),
52 MODULE_DEVICE_TABLE(dmi, chromeos_pstore_dmi_table);
55 * On x86 chromebooks/boxes, the firmware will keep the legacy VGA memory
56 * range untouched across reboots, so we use that to store our pstore
57 * contents for panic logs, etc.
59 static struct ramoops_platform_data chromeos_ramoops_data = {
61 .mem_address = 0xf00000,
62 .record_size = 0x40000,
63 .console_size = 0x20000,
64 .ftrace_size = 0x20000,
68 static struct platform_device chromeos_ramoops = {
71 .platform_data = &chromeos_ramoops_data,
76 static const struct acpi_device_id cros_ramoops_acpi_match[] = {
80 MODULE_DEVICE_TABLE(acpi, cros_ramoops_acpi_match);
82 static struct platform_driver chromeos_ramoops_acpi = {
84 .name = "chromeos_pstore",
85 .acpi_match_table = ACPI_PTR(cros_ramoops_acpi_match),
89 static int __init chromeos_probe_acpi(struct platform_device *pdev)
94 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
98 len = resource_size(res);
99 if (!res->start || !len)
102 pr_info("chromeos ramoops using acpi device.\n");
104 chromeos_ramoops_data.mem_size = len;
105 chromeos_ramoops_data.mem_address = res->start;
110 static bool __init chromeos_check_acpi(void)
112 if (!platform_driver_probe(&chromeos_ramoops_acpi, chromeos_probe_acpi))
117 static inline bool chromeos_check_acpi(void) { return false; }
120 static int __init chromeos_pstore_init(void)
124 /* First check ACPI for non-hardcoded values from firmware. */
125 acpi_dev_found = chromeos_check_acpi();
127 if (acpi_dev_found || dmi_check_system(chromeos_pstore_dmi_table))
128 return platform_device_register(&chromeos_ramoops);
133 static void __exit chromeos_pstore_exit(void)
135 platform_device_unregister(&chromeos_ramoops);
138 module_init(chromeos_pstore_init);
139 module_exit(chromeos_pstore_exit);
141 MODULE_DESCRIPTION("Chrome OS pstore module");
142 MODULE_LICENSE("GPL");