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");
92