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");
102