1 /* 2 * hwmon.c - part of lm_sensors, Linux kernel modules for hardware monitoring 3 * 4 * This file defines the sysfs class "hwmon", for use by sensors drivers. 5 * 6 * Copyright (C) 2005 Mark M. Hoffman <mhoffman@lightlink.com> 7 * 8 * This program is free software; you can redistribute it and/or modify 9 * it under the terms of the GNU General Public License as published by 10 * the Free Software Foundation; version 2 of the License. 11 */ 12 13 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt 14 15 #include <linux/module.h> 16 #include <linux/device.h> 17 #include <linux/err.h> 18 #include <linux/kdev_t.h> 19 #include <linux/idr.h> 20 #include <linux/hwmon.h> 21 #include <linux/gfp.h> 22 #include <linux/spinlock.h> 23 #include <linux/pci.h> 24 25 #define HWMON_ID_PREFIX "hwmon" 26 #define HWMON_ID_FORMAT HWMON_ID_PREFIX "%d" 27 28 static struct class *hwmon_class; 29 30 static DEFINE_IDA(hwmon_ida); 31 32 /** 33 * hwmon_device_register - register w/ hwmon 34 * @dev: the device to register 35 * 36 * hwmon_device_unregister() must be called when the device is no 37 * longer needed. 38 * 39 * Returns the pointer to the new device. 40 */ 41 struct device *hwmon_device_register(struct device *dev) 42 { 43 struct device *hwdev; 44 int id; 45 46 id = ida_simple_get(&hwmon_ida, 0, 0, GFP_KERNEL); 47 if (id < 0) 48 return ERR_PTR(id); 49 50 hwdev = device_create(hwmon_class, dev, MKDEV(0, 0), NULL, 51 HWMON_ID_FORMAT, id); 52 53 if (IS_ERR(hwdev)) 54 ida_simple_remove(&hwmon_ida, id); 55 56 return hwdev; 57 } 58 EXPORT_SYMBOL_GPL(hwmon_device_register); 59 60 /** 61 * hwmon_device_unregister - removes the previously registered class device 62 * 63 * @dev: the class device to destroy 64 */ 65 void hwmon_device_unregister(struct device *dev) 66 { 67 int id; 68 69 if (likely(sscanf(dev_name(dev), HWMON_ID_FORMAT, &id) == 1)) { 70 device_unregister(dev); 71 ida_simple_remove(&hwmon_ida, id); 72 } else 73 dev_dbg(dev->parent, 74 "hwmon_device_unregister() failed: bad class ID!\n"); 75 } 76 EXPORT_SYMBOL_GPL(hwmon_device_unregister); 77 78 static void __init hwmon_pci_quirks(void) 79 { 80 #if defined CONFIG_X86 && defined CONFIG_PCI 81 struct pci_dev *sb; 82 u16 base; 83 u8 enable; 84 85 /* Open access to 0x295-0x296 on MSI MS-7031 */ 86 sb = pci_get_device(PCI_VENDOR_ID_ATI, 0x436c, NULL); 87 if (sb && 88 (sb->subsystem_vendor == 0x1462 && /* MSI */ 89 sb->subsystem_device == 0x0031)) { /* MS-7031 */ 90 91 pci_read_config_byte(sb, 0x48, &enable); 92 pci_read_config_word(sb, 0x64, &base); 93 94 if (base == 0 && !(enable & BIT(2))) { 95 dev_info(&sb->dev, 96 "Opening wide generic port at 0x295\n"); 97 pci_write_config_word(sb, 0x64, 0x295); 98 pci_write_config_byte(sb, 0x48, enable | BIT(2)); 99 } 100 } 101 #endif 102 } 103 104 static int __init hwmon_init(void) 105 { 106 hwmon_pci_quirks(); 107 108 hwmon_class = class_create(THIS_MODULE, "hwmon"); 109 if (IS_ERR(hwmon_class)) { 110 pr_err("couldn't create sysfs class\n"); 111 return PTR_ERR(hwmon_class); 112 } 113 return 0; 114 } 115 116 static void __exit hwmon_exit(void) 117 { 118 class_destroy(hwmon_class); 119 } 120 121 subsys_initcall(hwmon_init); 122 module_exit(hwmon_exit); 123 124 MODULE_AUTHOR("Mark M. Hoffman <mhoffman@lightlink.com>"); 125 MODULE_DESCRIPTION("hardware monitoring sysfs/class support"); 126 MODULE_LICENSE("GPL"); 127 128