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/acpi.h> 12 #include <linux/dmi.h> 13 #include <linux/module.h> 14 #include <linux/platform_device.h> 15 #include <linux/pstore_ram.h> 16 17 static struct dmi_system_id chromeos_pstore_dmi_table[] __initdata = { 18 { 19 /* 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. 23 */ 24 .matches = { 25 DMI_MATCH(DMI_BIOS_VENDOR, "coreboot"), 26 DMI_MATCH(DMI_BIOS_VERSION, "Google_"), 27 }, 28 }, 29 { 30 /* x86-alex, the first Samsung Chromebook. */ 31 .matches = { 32 DMI_MATCH(DMI_SYS_VENDOR, "SAMSUNG ELECTRONICS CO., LTD."), 33 DMI_MATCH(DMI_PRODUCT_NAME, "Alex"), 34 }, 35 }, 36 { 37 /* x86-mario, the Cr-48 pilot device from Google. */ 38 .matches = { 39 DMI_MATCH(DMI_SYS_VENDOR, "IEC"), 40 DMI_MATCH(DMI_PRODUCT_NAME, "Mario"), 41 }, 42 }, 43 { 44 /* x86-zgb, the first Acer Chromebook. */ 45 .matches = { 46 DMI_MATCH(DMI_SYS_VENDOR, "ACER"), 47 DMI_MATCH(DMI_PRODUCT_NAME, "ZGB"), 48 }, 49 }, 50 { } 51 }; 52 MODULE_DEVICE_TABLE(dmi, chromeos_pstore_dmi_table); 53 54 /* 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. 58 */ 59 static struct ramoops_platform_data chromeos_ramoops_data = { 60 .mem_size = 0x100000, 61 .mem_address = 0xf00000, 62 .record_size = 0x40000, 63 .console_size = 0x20000, 64 .ftrace_size = 0x20000, 65 .dump_oops = 1, 66 }; 67 68 static struct platform_device chromeos_ramoops = { 69 .name = "ramoops", 70 .dev = { 71 .platform_data = &chromeos_ramoops_data, 72 }, 73 }; 74 75 #ifdef CONFIG_ACPI 76 static const struct acpi_device_id cros_ramoops_acpi_match[] = { 77 { "GOOG9999", 0 }, 78 { } 79 }; 80 MODULE_DEVICE_TABLE(acpi, cros_ramoops_acpi_match); 81 82 static struct platform_driver chromeos_ramoops_acpi = { 83 .driver = { 84 .name = "chromeos_pstore", 85 .acpi_match_table = ACPI_PTR(cros_ramoops_acpi_match), 86 }, 87 }; 88 89 static int __init chromeos_probe_acpi(struct platform_device *pdev) 90 { 91 struct resource *res; 92 resource_size_t len; 93 94 res = platform_get_resource(pdev, IORESOURCE_MEM, 0); 95 if (!res) 96 return -ENOMEM; 97 98 len = resource_size(res); 99 if (!res->start || !len) 100 return -ENOMEM; 101 102 pr_info("chromeos ramoops using acpi device.\n"); 103 104 chromeos_ramoops_data.mem_size = len; 105 chromeos_ramoops_data.mem_address = res->start; 106 107 return 0; 108 } 109 110 static bool __init chromeos_check_acpi(void) 111 { 112 if (!platform_driver_probe(&chromeos_ramoops_acpi, chromeos_probe_acpi)) 113 return true; 114 return false; 115 } 116 #else 117 static inline bool chromeos_check_acpi(void) { return false; } 118 #endif 119 120 static int __init chromeos_pstore_init(void) 121 { 122 bool acpi_dev_found; 123 124 /* First check ACPI for non-hardcoded values from firmware. */ 125 acpi_dev_found = chromeos_check_acpi(); 126 127 if (acpi_dev_found || dmi_check_system(chromeos_pstore_dmi_table)) 128 return platform_device_register(&chromeos_ramoops); 129 130 return -ENODEV; 131 } 132 133 static void __exit chromeos_pstore_exit(void) 134 { 135 platform_device_unregister(&chromeos_ramoops); 136 } 137 138 module_init(chromeos_pstore_init); 139 module_exit(chromeos_pstore_exit); 140 141 MODULE_DESCRIPTION("Chrome OS pstore module"); 142 MODULE_LICENSE("GPL"); 143