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1// SPDX-License-Identifier: GPL-2.0-or-later2/*3 * k8temp.c - Linux kernel module for hardware monitoring4 *5 * Copyright (C) 2006 Rudolf Marek <r.marek@assembler.cz>6 *7 * Inspired from the w83785 and amd756 drivers.8 */9 10#include <linux/module.h>11#include <linux/init.h>12#include <linux/slab.h>13#include <linux/pci.h>14#include <linux/hwmon.h>15#include <linux/err.h>16#include <linux/mutex.h>17#include <asm/processor.h>18 19#define TEMP_FROM_REG(val) (((((val) >> 16) & 0xff) - 49) * 1000)20#define REG_TEMP 0xe421#define SEL_PLACE 0x4022#define SEL_CORE 0x0423 24struct k8temp_data {25 struct mutex update_lock;26 27 /* registers values */28 u8 sensorsp; /* sensor presence bits - SEL_CORE, SEL_PLACE */29 u8 swap_core_select; /* meaning of SEL_CORE is inverted */30 u32 temp_offset;31};32 33static const struct pci_device_id k8temp_ids[] = {34 { PCI_DEVICE(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_K8_NB_MISC) },35 { 0 },36};37MODULE_DEVICE_TABLE(pci, k8temp_ids);38 39static int is_rev_g_desktop(u8 model)40{41 u32 brandidx;42 43 if (model < 0x69)44 return 0;45 46 if (model == 0xc1 || model == 0x6c || model == 0x7c)47 return 0;48 49 /*50 * Differentiate between AM2 and ASB1.51 * See "Constructing the processor Name String" in "Revision52 * Guide for AMD NPT Family 0Fh Processors" (33610).53 */54 brandidx = cpuid_ebx(0x80000001);55 brandidx = (brandidx >> 9) & 0x1f;56 57 /* Single core */58 if ((model == 0x6f || model == 0x7f) &&59 (brandidx == 0x7 || brandidx == 0x9 || brandidx == 0xc))60 return 0;61 62 /* Dual core */63 if (model == 0x6b &&64 (brandidx == 0xb || brandidx == 0xc))65 return 0;66 67 return 1;68}69 70static umode_t71k8temp_is_visible(const void *drvdata, enum hwmon_sensor_types type,72 u32 attr, int channel)73{74 const struct k8temp_data *data = drvdata;75 76 if ((channel & 1) && !(data->sensorsp & SEL_PLACE))77 return 0;78 79 if ((channel & 2) && !(data->sensorsp & SEL_CORE))80 return 0;81 82 return 0444;83}84 85static int86k8temp_read(struct device *dev, enum hwmon_sensor_types type,87 u32 attr, int channel, long *val)88{89 struct k8temp_data *data = dev_get_drvdata(dev);90 struct pci_dev *pdev = to_pci_dev(dev->parent);91 int core, place;92 u32 temp;93 u8 tmp;94 95 core = (channel >> 1) & 1;96 place = channel & 1;97 98 core ^= data->swap_core_select;99 100 mutex_lock(&data->update_lock);101 pci_read_config_byte(pdev, REG_TEMP, &tmp);102 tmp &= ~(SEL_PLACE | SEL_CORE);103 if (core)104 tmp |= SEL_CORE;105 if (place)106 tmp |= SEL_PLACE;107 pci_write_config_byte(pdev, REG_TEMP, tmp);108 pci_read_config_dword(pdev, REG_TEMP, &temp);109 mutex_unlock(&data->update_lock);110 111 *val = TEMP_FROM_REG(temp) + data->temp_offset;112 113 return 0;114}115 116static const struct hwmon_ops k8temp_ops = {117 .is_visible = k8temp_is_visible,118 .read = k8temp_read,119};120 121static const struct hwmon_channel_info * const k8temp_info[] = {122 HWMON_CHANNEL_INFO(temp,123 HWMON_T_INPUT, HWMON_T_INPUT, HWMON_T_INPUT, HWMON_T_INPUT),124 NULL125};126 127static const struct hwmon_chip_info k8temp_chip_info = {128 .ops = &k8temp_ops,129 .info = k8temp_info,130};131 132static int k8temp_probe(struct pci_dev *pdev,133 const struct pci_device_id *id)134{135 u8 scfg;136 u32 temp;137 u8 model, stepping;138 struct k8temp_data *data;139 struct device *hwmon_dev;140 141 data = devm_kzalloc(&pdev->dev, sizeof(struct k8temp_data), GFP_KERNEL);142 if (!data)143 return -ENOMEM;144 145 model = boot_cpu_data.x86_model;146 stepping = boot_cpu_data.x86_stepping;147 148 /* feature available since SH-C0, exclude older revisions */149 if ((model == 4 && stepping == 0) ||150 (model == 5 && stepping <= 1))151 return -ENODEV;152 153 /*154 * AMD NPT family 0fh, i.e. RevF and RevG:155 * meaning of SEL_CORE bit is inverted156 */157 if (model >= 0x40) {158 data->swap_core_select = 1;159 dev_warn(&pdev->dev,160 "Temperature readouts might be wrong - check erratum #141\n");161 }162 163 /*164 * RevG desktop CPUs (i.e. no socket S1G1 or ASB1 parts) need165 * additional offset, otherwise reported temperature is below166 * ambient temperature167 */168 if (is_rev_g_desktop(model))169 data->temp_offset = 21000;170 171 pci_read_config_byte(pdev, REG_TEMP, &scfg);172 scfg &= ~(SEL_PLACE | SEL_CORE); /* Select sensor 0, core0 */173 pci_write_config_byte(pdev, REG_TEMP, scfg);174 pci_read_config_byte(pdev, REG_TEMP, &scfg);175 176 if (scfg & (SEL_PLACE | SEL_CORE)) {177 dev_err(&pdev->dev, "Configuration bit(s) stuck at 1!\n");178 return -ENODEV;179 }180 181 scfg |= (SEL_PLACE | SEL_CORE);182 pci_write_config_byte(pdev, REG_TEMP, scfg);183 184 /* now we know if we can change core and/or sensor */185 pci_read_config_byte(pdev, REG_TEMP, &data->sensorsp);186 187 if (data->sensorsp & SEL_PLACE) {188 scfg &= ~SEL_CORE; /* Select sensor 1, core0 */189 pci_write_config_byte(pdev, REG_TEMP, scfg);190 pci_read_config_dword(pdev, REG_TEMP, &temp);191 scfg |= SEL_CORE; /* prepare for next selection */192 if (!((temp >> 16) & 0xff)) /* if temp is 0 -49C is unlikely */193 data->sensorsp &= ~SEL_PLACE;194 }195 196 if (data->sensorsp & SEL_CORE) {197 scfg &= ~SEL_PLACE; /* Select sensor 0, core1 */198 pci_write_config_byte(pdev, REG_TEMP, scfg);199 pci_read_config_dword(pdev, REG_TEMP, &temp);200 if (!((temp >> 16) & 0xff)) /* if temp is 0 -49C is unlikely */201 data->sensorsp &= ~SEL_CORE;202 }203 204 mutex_init(&data->update_lock);205 206 hwmon_dev = devm_hwmon_device_register_with_info(&pdev->dev,207 "k8temp",208 data,209 &k8temp_chip_info,210 NULL);211 212 return PTR_ERR_OR_ZERO(hwmon_dev);213}214 215static struct pci_driver k8temp_driver = {216 .name = "k8temp",217 .id_table = k8temp_ids,218 .probe = k8temp_probe,219};220 221module_pci_driver(k8temp_driver);222 223MODULE_AUTHOR("Rudolf Marek <r.marek@assembler.cz>");224MODULE_DESCRIPTION("AMD K8 core temperature monitor");225MODULE_LICENSE("GPL");226