xref: /linux/drivers/hwmon/k8temp.c (revision 2dbc0838bcf24ca59cabc3130cf3b1d6809cdcd4)
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/jiffies.h>
14 #include <linux/pci.h>
15 #include <linux/hwmon.h>
16 #include <linux/hwmon-sysfs.h>
17 #include <linux/err.h>
18 #include <linux/mutex.h>
19 #include <asm/processor.h>
20 
21 #define TEMP_FROM_REG(val)	(((((val) >> 16) & 0xff) - 49) * 1000)
22 #define REG_TEMP	0xe4
23 #define SEL_PLACE	0x40
24 #define SEL_CORE	0x04
25 
26 struct k8temp_data {
27 	struct device *hwmon_dev;
28 	struct mutex update_lock;
29 	const char *name;
30 	char valid;		/* zero until following fields are valid */
31 	unsigned long last_updated;	/* in jiffies */
32 
33 	/* registers values */
34 	u8 sensorsp;		/* sensor presence bits - SEL_CORE, SEL_PLACE */
35 	u32 temp[2][2];		/* core, place */
36 	u8 swap_core_select;    /* meaning of SEL_CORE is inverted */
37 	u32 temp_offset;
38 };
39 
40 static struct k8temp_data *k8temp_update_device(struct device *dev)
41 {
42 	struct k8temp_data *data = dev_get_drvdata(dev);
43 	struct pci_dev *pdev = to_pci_dev(dev);
44 	u8 tmp;
45 
46 	mutex_lock(&data->update_lock);
47 
48 	if (!data->valid
49 	    || time_after(jiffies, data->last_updated + HZ)) {
50 		pci_read_config_byte(pdev, REG_TEMP, &tmp);
51 		tmp &= ~(SEL_PLACE | SEL_CORE);	/* Select sensor 0, core0 */
52 		pci_write_config_byte(pdev, REG_TEMP, tmp);
53 		pci_read_config_dword(pdev, REG_TEMP, &data->temp[0][0]);
54 
55 		if (data->sensorsp & SEL_PLACE) {
56 			tmp |= SEL_PLACE;	/* Select sensor 1, core0 */
57 			pci_write_config_byte(pdev, REG_TEMP, tmp);
58 			pci_read_config_dword(pdev, REG_TEMP,
59 					      &data->temp[0][1]);
60 		}
61 
62 		if (data->sensorsp & SEL_CORE) {
63 			tmp &= ~SEL_PLACE;	/* Select sensor 0, core1 */
64 			tmp |= SEL_CORE;
65 			pci_write_config_byte(pdev, REG_TEMP, tmp);
66 			pci_read_config_dword(pdev, REG_TEMP,
67 					      &data->temp[1][0]);
68 
69 			if (data->sensorsp & SEL_PLACE) {
70 				tmp |= SEL_PLACE; /* Select sensor 1, core1 */
71 				pci_write_config_byte(pdev, REG_TEMP, tmp);
72 				pci_read_config_dword(pdev, REG_TEMP,
73 						      &data->temp[1][1]);
74 			}
75 		}
76 
77 		data->last_updated = jiffies;
78 		data->valid = 1;
79 	}
80 
81 	mutex_unlock(&data->update_lock);
82 	return data;
83 }
84 
85 /*
86  * Sysfs stuff
87  */
88 
89 static ssize_t name_show(struct device *dev, struct device_attribute
90 			 *devattr, char *buf)
91 {
92 	struct k8temp_data *data = dev_get_drvdata(dev);
93 
94 	return sprintf(buf, "%s\n", data->name);
95 }
96 
97 
98 static ssize_t temp_show(struct device *dev, struct device_attribute *devattr,
99 			 char *buf)
100 {
101 	struct sensor_device_attribute_2 *attr =
102 	    to_sensor_dev_attr_2(devattr);
103 	int core = attr->nr;
104 	int place = attr->index;
105 	int temp;
106 	struct k8temp_data *data = k8temp_update_device(dev);
107 
108 	if (data->swap_core_select && (data->sensorsp & SEL_CORE))
109 		core = core ? 0 : 1;
110 
111 	temp = TEMP_FROM_REG(data->temp[core][place]) + data->temp_offset;
112 
113 	return sprintf(buf, "%d\n", temp);
114 }
115 
116 /* core, place */
117 
118 static SENSOR_DEVICE_ATTR_2_RO(temp1_input, temp, 0, 0);
119 static SENSOR_DEVICE_ATTR_2_RO(temp2_input, temp, 0, 1);
120 static SENSOR_DEVICE_ATTR_2_RO(temp3_input, temp, 1, 0);
121 static SENSOR_DEVICE_ATTR_2_RO(temp4_input, temp, 1, 1);
122 static DEVICE_ATTR_RO(name);
123 
124 static const struct pci_device_id k8temp_ids[] = {
125 	{ PCI_DEVICE(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_K8_NB_MISC) },
126 	{ 0 },
127 };
128 
129 MODULE_DEVICE_TABLE(pci, k8temp_ids);
130 
131 static int is_rev_g_desktop(u8 model)
132 {
133 	u32 brandidx;
134 
135 	if (model < 0x69)
136 		return 0;
137 
138 	if (model == 0xc1 || model == 0x6c || model == 0x7c)
139 		return 0;
140 
141 	/*
142 	 * Differentiate between AM2 and ASB1.
143 	 * See "Constructing the processor Name String" in "Revision
144 	 * Guide for AMD NPT Family 0Fh Processors" (33610).
145 	 */
146 	brandidx = cpuid_ebx(0x80000001);
147 	brandidx = (brandidx >> 9) & 0x1f;
148 
149 	/* Single core */
150 	if ((model == 0x6f || model == 0x7f) &&
151 	    (brandidx == 0x7 || brandidx == 0x9 || brandidx == 0xc))
152 		return 0;
153 
154 	/* Dual core */
155 	if (model == 0x6b &&
156 	    (brandidx == 0xb || brandidx == 0xc))
157 		return 0;
158 
159 	return 1;
160 }
161 
162 static int k8temp_probe(struct pci_dev *pdev,
163 				  const struct pci_device_id *id)
164 {
165 	int err;
166 	u8 scfg;
167 	u32 temp;
168 	u8 model, stepping;
169 	struct k8temp_data *data;
170 
171 	data = devm_kzalloc(&pdev->dev, sizeof(struct k8temp_data), GFP_KERNEL);
172 	if (!data)
173 		return -ENOMEM;
174 
175 	model = boot_cpu_data.x86_model;
176 	stepping = boot_cpu_data.x86_stepping;
177 
178 	/* feature available since SH-C0, exclude older revisions */
179 	if ((model == 4 && stepping == 0) ||
180 	    (model == 5 && stepping <= 1))
181 		return -ENODEV;
182 
183 	/*
184 	 * AMD NPT family 0fh, i.e. RevF and RevG:
185 	 * meaning of SEL_CORE bit is inverted
186 	 */
187 	if (model >= 0x40) {
188 		data->swap_core_select = 1;
189 		dev_warn(&pdev->dev,
190 			 "Temperature readouts might be wrong - check erratum #141\n");
191 	}
192 
193 	/*
194 	 * RevG desktop CPUs (i.e. no socket S1G1 or ASB1 parts) need
195 	 * additional offset, otherwise reported temperature is below
196 	 * ambient temperature
197 	 */
198 	if (is_rev_g_desktop(model))
199 		data->temp_offset = 21000;
200 
201 	pci_read_config_byte(pdev, REG_TEMP, &scfg);
202 	scfg &= ~(SEL_PLACE | SEL_CORE);	/* Select sensor 0, core0 */
203 	pci_write_config_byte(pdev, REG_TEMP, scfg);
204 	pci_read_config_byte(pdev, REG_TEMP, &scfg);
205 
206 	if (scfg & (SEL_PLACE | SEL_CORE)) {
207 		dev_err(&pdev->dev, "Configuration bit(s) stuck at 1!\n");
208 		return -ENODEV;
209 	}
210 
211 	scfg |= (SEL_PLACE | SEL_CORE);
212 	pci_write_config_byte(pdev, REG_TEMP, scfg);
213 
214 	/* now we know if we can change core and/or sensor */
215 	pci_read_config_byte(pdev, REG_TEMP, &data->sensorsp);
216 
217 	if (data->sensorsp & SEL_PLACE) {
218 		scfg &= ~SEL_CORE;	/* Select sensor 1, core0 */
219 		pci_write_config_byte(pdev, REG_TEMP, scfg);
220 		pci_read_config_dword(pdev, REG_TEMP, &temp);
221 		scfg |= SEL_CORE;	/* prepare for next selection */
222 		if (!((temp >> 16) & 0xff)) /* if temp is 0 -49C is unlikely */
223 			data->sensorsp &= ~SEL_PLACE;
224 	}
225 
226 	if (data->sensorsp & SEL_CORE) {
227 		scfg &= ~SEL_PLACE;	/* Select sensor 0, core1 */
228 		pci_write_config_byte(pdev, REG_TEMP, scfg);
229 		pci_read_config_dword(pdev, REG_TEMP, &temp);
230 		if (!((temp >> 16) & 0xff)) /* if temp is 0 -49C is unlikely */
231 			data->sensorsp &= ~SEL_CORE;
232 	}
233 
234 	data->name = "k8temp";
235 	mutex_init(&data->update_lock);
236 	pci_set_drvdata(pdev, data);
237 
238 	/* Register sysfs hooks */
239 	err = device_create_file(&pdev->dev,
240 			   &sensor_dev_attr_temp1_input.dev_attr);
241 	if (err)
242 		goto exit_remove;
243 
244 	/* sensor can be changed and reports something */
245 	if (data->sensorsp & SEL_PLACE) {
246 		err = device_create_file(&pdev->dev,
247 				   &sensor_dev_attr_temp2_input.dev_attr);
248 		if (err)
249 			goto exit_remove;
250 	}
251 
252 	/* core can be changed and reports something */
253 	if (data->sensorsp & SEL_CORE) {
254 		err = device_create_file(&pdev->dev,
255 				   &sensor_dev_attr_temp3_input.dev_attr);
256 		if (err)
257 			goto exit_remove;
258 		if (data->sensorsp & SEL_PLACE) {
259 			err = device_create_file(&pdev->dev,
260 					   &sensor_dev_attr_temp4_input.
261 					   dev_attr);
262 			if (err)
263 				goto exit_remove;
264 		}
265 	}
266 
267 	err = device_create_file(&pdev->dev, &dev_attr_name);
268 	if (err)
269 		goto exit_remove;
270 
271 	data->hwmon_dev = hwmon_device_register(&pdev->dev);
272 
273 	if (IS_ERR(data->hwmon_dev)) {
274 		err = PTR_ERR(data->hwmon_dev);
275 		goto exit_remove;
276 	}
277 
278 	return 0;
279 
280 exit_remove:
281 	device_remove_file(&pdev->dev,
282 			   &sensor_dev_attr_temp1_input.dev_attr);
283 	device_remove_file(&pdev->dev,
284 			   &sensor_dev_attr_temp2_input.dev_attr);
285 	device_remove_file(&pdev->dev,
286 			   &sensor_dev_attr_temp3_input.dev_attr);
287 	device_remove_file(&pdev->dev,
288 			   &sensor_dev_attr_temp4_input.dev_attr);
289 	device_remove_file(&pdev->dev, &dev_attr_name);
290 	return err;
291 }
292 
293 static void k8temp_remove(struct pci_dev *pdev)
294 {
295 	struct k8temp_data *data = pci_get_drvdata(pdev);
296 
297 	hwmon_device_unregister(data->hwmon_dev);
298 	device_remove_file(&pdev->dev,
299 			   &sensor_dev_attr_temp1_input.dev_attr);
300 	device_remove_file(&pdev->dev,
301 			   &sensor_dev_attr_temp2_input.dev_attr);
302 	device_remove_file(&pdev->dev,
303 			   &sensor_dev_attr_temp3_input.dev_attr);
304 	device_remove_file(&pdev->dev,
305 			   &sensor_dev_attr_temp4_input.dev_attr);
306 	device_remove_file(&pdev->dev, &dev_attr_name);
307 }
308 
309 static struct pci_driver k8temp_driver = {
310 	.name = "k8temp",
311 	.id_table = k8temp_ids,
312 	.probe = k8temp_probe,
313 	.remove = k8temp_remove,
314 };
315 
316 module_pci_driver(k8temp_driver);
317 
318 MODULE_AUTHOR("Rudolf Marek <r.marek@assembler.cz>");
319 MODULE_DESCRIPTION("AMD K8 core temperature monitor");
320 MODULE_LICENSE("GPL");
321