1 // SPDX-License-Identifier: GPL-2.0-or-later 2 /* 3 * k8temp.c - Linux kernel module for hardware monitoring 4 * 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 0xe4 21 #define SEL_PLACE 0x40 22 #define SEL_CORE 0x04 23 24 struct 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 33 static const struct pci_device_id k8temp_ids[] = { 34 { PCI_DEVICE(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_K8_NB_MISC) }, 35 { 0 }, 36 }; 37 MODULE_DEVICE_TABLE(pci, k8temp_ids); 38 39 static 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 "Revision 52 * 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 70 static umode_t 71 k8temp_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 85 static int 86 k8temp_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 } 115 116 static const struct hwmon_ops k8temp_ops = { 117 .is_visible = k8temp_is_visible, 118 .read = k8temp_read, 119 }; 120 121 static 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 NULL 125 }; 126 127 static const struct hwmon_chip_info k8temp_chip_info = { 128 .ops = &k8temp_ops, 129 .info = k8temp_info, 130 }; 131 132 static 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 inverted 156 */ 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) need 165 * additional offset, otherwise reported temperature is below 166 * ambient temperature 167 */ 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 } 214 215 static struct pci_driver k8temp_driver = { 216 .name = "k8temp", 217 .id_table = k8temp_ids, 218 .probe = k8temp_probe, 219 }; 220 221 module_pci_driver(k8temp_driver); 222 223 MODULE_AUTHOR("Rudolf Marek <r.marek@assembler.cz>"); 224 MODULE_DESCRIPTION("AMD K8 core temperature monitor"); 225 MODULE_LICENSE("GPL"); 226