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#include <linux/module.h> 14#include <linux/device.h> 15#include <linux/err.h> 16#include <linux/kdev_t.h> 17#include <linux/idr.h> 18#include <linux/hwmon.h> 19#include <linux/gfp.h> 20#include <linux/spinlock.h> 21#include <linux/pci.h> 22 23#define HWMON_ID_PREFIX "hwmon" 24#define HWMON_ID_FORMAT HWMON_ID_PREFIX "%d" 25 26static struct class *hwmon_class; 27 28static DEFINE_IDR(hwmon_idr); 29static DEFINE_SPINLOCK(idr_lock); 30 31/** 32 * hwmon_device_register - register w/ hwmon 33 * @dev: the device to register 34 * 35 * hwmon_device_unregister() must be called when the device is no 36 * longer needed. 37 * 38 * Returns the pointer to the new device. 39 */ 40struct device *hwmon_device_register(struct device *dev) 41{ 42 struct device *hwdev; 43 int id, err; 44 45again: 46 if (unlikely(idr_pre_get(&hwmon_idr, GFP_KERNEL) == 0)) 47 return ERR_PTR(-ENOMEM); 48 49 spin_lock(&idr_lock); 50 err = idr_get_new(&hwmon_idr, NULL, &id); 51 spin_unlock(&idr_lock); 52 53 if (unlikely(err == -EAGAIN)) 54 goto again; 55 else if (unlikely(err)) 56 return ERR_PTR(err); 57 58 id = id & MAX_ID_MASK; 59 hwdev = device_create(hwmon_class, dev, MKDEV(0, 0), NULL, 60 HWMON_ID_FORMAT, id); 61 62 if (IS_ERR(hwdev)) { 63 spin_lock(&idr_lock); 64 idr_remove(&hwmon_idr, id); 65 spin_unlock(&idr_lock); 66 } 67 68 return hwdev; 69} 70 71/** 72 * hwmon_device_unregister - removes the previously registered class device 73 * 74 * @dev: the class device to destroy 75 */ 76void hwmon_device_unregister(struct device *dev) 77{ 78 int id; 79 80 if (likely(sscanf(dev_name(dev), HWMON_ID_FORMAT, &id) == 1)) { 81 device_unregister(dev); 82 spin_lock(&idr_lock); 83 idr_remove(&hwmon_idr, id); 84 spin_unlock(&idr_lock); 85 } else 86 dev_dbg(dev->parent, 87 "hwmon_device_unregister() failed: bad class ID!\n"); 88} 89 90static void __init hwmon_pci_quirks(void) 91{ 92#if defined CONFIG_X86 && defined CONFIG_PCI 93 struct pci_dev *sb; 94 u16 base; 95 u8 enable; 96 97 /* Open access to 0x295-0x296 on MSI MS-7031 */ 98 sb = pci_get_device(PCI_VENDOR_ID_ATI, 0x436c, NULL); 99 if (sb && 100 (sb->subsystem_vendor == 0x1462 && /* MSI */ 101 sb->subsystem_device == 0x0031)) { /* MS-7031 */ 102 103 pci_read_config_byte(sb, 0x48, &enable); 104 pci_read_config_word(sb, 0x64, &base); 105 106 if (base == 0 && !(enable & BIT(2))) { 107 dev_info(&sb->dev, 108 "Opening wide generic port at 0x295\n"); 109 pci_write_config_word(sb, 0x64, 0x295); 110 pci_write_config_byte(sb, 0x48, enable | BIT(2)); 111 } 112 } 113#endif 114} 115 116static int __init hwmon_init(void) 117{ 118 hwmon_pci_quirks(); 119 120 hwmon_class = class_create(THIS_MODULE, "hwmon"); 121 if (IS_ERR(hwmon_class)) { 122 printk(KERN_ERR "hwmon.c: couldn't create sysfs class\n"); 123 return PTR_ERR(hwmon_class); 124 } 125 return 0; 126} 127 128static void __exit hwmon_exit(void) 129{ 130 class_destroy(hwmon_class); 131} 132 133subsys_initcall(hwmon_init); 134module_exit(hwmon_exit); 135 136EXPORT_SYMBOL_GPL(hwmon_device_register); 137EXPORT_SYMBOL_GPL(hwmon_device_unregister); 138 139MODULE_AUTHOR("Mark M. Hoffman <mhoffman@lightlink.com>"); 140MODULE_DESCRIPTION("hardware monitoring sysfs/class support"); 141MODULE_LICENSE("GPL"); 142