xref: /openbmc/linux/drivers/hwmon/k8temp.c (revision e3b9f1e8)
1 /*
2  * k8temp.c - Linux kernel module for hardware monitoring
3  *
4  * Copyright (C) 2006 Rudolf Marek <r.marek@assembler.cz>
5  *
6  * Inspired from the w83785 and amd756 drivers.
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; either version 2 of the License, or
11  * (at your option) any later version.
12  *
13  * This program is distributed in the hope that it will be useful,
14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
16  * GNU General Public License for more details.
17  *
18  * You should have received a copy of the GNU General Public License
19  * along with this program; if not, write to the Free Software
20  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
21  * 02110-1301 USA.
22  */
23 
24 #include <linux/module.h>
25 #include <linux/init.h>
26 #include <linux/slab.h>
27 #include <linux/jiffies.h>
28 #include <linux/pci.h>
29 #include <linux/hwmon.h>
30 #include <linux/hwmon-sysfs.h>
31 #include <linux/err.h>
32 #include <linux/mutex.h>
33 #include <asm/processor.h>
34 
35 #define TEMP_FROM_REG(val)	(((((val) >> 16) & 0xff) - 49) * 1000)
36 #define REG_TEMP	0xe4
37 #define SEL_PLACE	0x40
38 #define SEL_CORE	0x04
39 
40 struct k8temp_data {
41 	struct device *hwmon_dev;
42 	struct mutex update_lock;
43 	const char *name;
44 	char valid;		/* zero until following fields are valid */
45 	unsigned long last_updated;	/* in jiffies */
46 
47 	/* registers values */
48 	u8 sensorsp;		/* sensor presence bits - SEL_CORE, SEL_PLACE */
49 	u32 temp[2][2];		/* core, place */
50 	u8 swap_core_select;    /* meaning of SEL_CORE is inverted */
51 	u32 temp_offset;
52 };
53 
54 static struct k8temp_data *k8temp_update_device(struct device *dev)
55 {
56 	struct k8temp_data *data = dev_get_drvdata(dev);
57 	struct pci_dev *pdev = to_pci_dev(dev);
58 	u8 tmp;
59 
60 	mutex_lock(&data->update_lock);
61 
62 	if (!data->valid
63 	    || time_after(jiffies, data->last_updated + HZ)) {
64 		pci_read_config_byte(pdev, REG_TEMP, &tmp);
65 		tmp &= ~(SEL_PLACE | SEL_CORE);	/* Select sensor 0, core0 */
66 		pci_write_config_byte(pdev, REG_TEMP, tmp);
67 		pci_read_config_dword(pdev, REG_TEMP, &data->temp[0][0]);
68 
69 		if (data->sensorsp & SEL_PLACE) {
70 			tmp |= SEL_PLACE;	/* Select sensor 1, core0 */
71 			pci_write_config_byte(pdev, REG_TEMP, tmp);
72 			pci_read_config_dword(pdev, REG_TEMP,
73 					      &data->temp[0][1]);
74 		}
75 
76 		if (data->sensorsp & SEL_CORE) {
77 			tmp &= ~SEL_PLACE;	/* Select sensor 0, core1 */
78 			tmp |= SEL_CORE;
79 			pci_write_config_byte(pdev, REG_TEMP, tmp);
80 			pci_read_config_dword(pdev, REG_TEMP,
81 					      &data->temp[1][0]);
82 
83 			if (data->sensorsp & SEL_PLACE) {
84 				tmp |= SEL_PLACE; /* Select sensor 1, core1 */
85 				pci_write_config_byte(pdev, REG_TEMP, tmp);
86 				pci_read_config_dword(pdev, REG_TEMP,
87 						      &data->temp[1][1]);
88 			}
89 		}
90 
91 		data->last_updated = jiffies;
92 		data->valid = 1;
93 	}
94 
95 	mutex_unlock(&data->update_lock);
96 	return data;
97 }
98 
99 /*
100  * Sysfs stuff
101  */
102 
103 static ssize_t name_show(struct device *dev, struct device_attribute
104 			 *devattr, char *buf)
105 {
106 	struct k8temp_data *data = dev_get_drvdata(dev);
107 
108 	return sprintf(buf, "%s\n", data->name);
109 }
110 
111 
112 static ssize_t show_temp(struct device *dev,
113 			 struct device_attribute *devattr, char *buf)
114 {
115 	struct sensor_device_attribute_2 *attr =
116 	    to_sensor_dev_attr_2(devattr);
117 	int core = attr->nr;
118 	int place = attr->index;
119 	int temp;
120 	struct k8temp_data *data = k8temp_update_device(dev);
121 
122 	if (data->swap_core_select && (data->sensorsp & SEL_CORE))
123 		core = core ? 0 : 1;
124 
125 	temp = TEMP_FROM_REG(data->temp[core][place]) + data->temp_offset;
126 
127 	return sprintf(buf, "%d\n", temp);
128 }
129 
130 /* core, place */
131 
132 static SENSOR_DEVICE_ATTR_2(temp1_input, S_IRUGO, show_temp, NULL, 0, 0);
133 static SENSOR_DEVICE_ATTR_2(temp2_input, S_IRUGO, show_temp, NULL, 0, 1);
134 static SENSOR_DEVICE_ATTR_2(temp3_input, S_IRUGO, show_temp, NULL, 1, 0);
135 static SENSOR_DEVICE_ATTR_2(temp4_input, S_IRUGO, show_temp, NULL, 1, 1);
136 static DEVICE_ATTR_RO(name);
137 
138 static const struct pci_device_id k8temp_ids[] = {
139 	{ PCI_DEVICE(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_K8_NB_MISC) },
140 	{ 0 },
141 };
142 
143 MODULE_DEVICE_TABLE(pci, k8temp_ids);
144 
145 static int is_rev_g_desktop(u8 model)
146 {
147 	u32 brandidx;
148 
149 	if (model < 0x69)
150 		return 0;
151 
152 	if (model == 0xc1 || model == 0x6c || model == 0x7c)
153 		return 0;
154 
155 	/*
156 	 * Differentiate between AM2 and ASB1.
157 	 * See "Constructing the processor Name String" in "Revision
158 	 * Guide for AMD NPT Family 0Fh Processors" (33610).
159 	 */
160 	brandidx = cpuid_ebx(0x80000001);
161 	brandidx = (brandidx >> 9) & 0x1f;
162 
163 	/* Single core */
164 	if ((model == 0x6f || model == 0x7f) &&
165 	    (brandidx == 0x7 || brandidx == 0x9 || brandidx == 0xc))
166 		return 0;
167 
168 	/* Dual core */
169 	if (model == 0x6b &&
170 	    (brandidx == 0xb || brandidx == 0xc))
171 		return 0;
172 
173 	return 1;
174 }
175 
176 static int k8temp_probe(struct pci_dev *pdev,
177 				  const struct pci_device_id *id)
178 {
179 	int err;
180 	u8 scfg;
181 	u32 temp;
182 	u8 model, stepping;
183 	struct k8temp_data *data;
184 
185 	data = devm_kzalloc(&pdev->dev, sizeof(struct k8temp_data), GFP_KERNEL);
186 	if (!data)
187 		return -ENOMEM;
188 
189 	model = boot_cpu_data.x86_model;
190 	stepping = boot_cpu_data.x86_stepping;
191 
192 	/* feature available since SH-C0, exclude older revisions */
193 	if ((model == 4 && stepping == 0) ||
194 	    (model == 5 && stepping <= 1))
195 		return -ENODEV;
196 
197 	/*
198 	 * AMD NPT family 0fh, i.e. RevF and RevG:
199 	 * meaning of SEL_CORE bit is inverted
200 	 */
201 	if (model >= 0x40) {
202 		data->swap_core_select = 1;
203 		dev_warn(&pdev->dev,
204 			 "Temperature readouts might be wrong - check erratum #141\n");
205 	}
206 
207 	/*
208 	 * RevG desktop CPUs (i.e. no socket S1G1 or ASB1 parts) need
209 	 * additional offset, otherwise reported temperature is below
210 	 * ambient temperature
211 	 */
212 	if (is_rev_g_desktop(model))
213 		data->temp_offset = 21000;
214 
215 	pci_read_config_byte(pdev, REG_TEMP, &scfg);
216 	scfg &= ~(SEL_PLACE | SEL_CORE);	/* Select sensor 0, core0 */
217 	pci_write_config_byte(pdev, REG_TEMP, scfg);
218 	pci_read_config_byte(pdev, REG_TEMP, &scfg);
219 
220 	if (scfg & (SEL_PLACE | SEL_CORE)) {
221 		dev_err(&pdev->dev, "Configuration bit(s) stuck at 1!\n");
222 		return -ENODEV;
223 	}
224 
225 	scfg |= (SEL_PLACE | SEL_CORE);
226 	pci_write_config_byte(pdev, REG_TEMP, scfg);
227 
228 	/* now we know if we can change core and/or sensor */
229 	pci_read_config_byte(pdev, REG_TEMP, &data->sensorsp);
230 
231 	if (data->sensorsp & SEL_PLACE) {
232 		scfg &= ~SEL_CORE;	/* Select sensor 1, core0 */
233 		pci_write_config_byte(pdev, REG_TEMP, scfg);
234 		pci_read_config_dword(pdev, REG_TEMP, &temp);
235 		scfg |= SEL_CORE;	/* prepare for next selection */
236 		if (!((temp >> 16) & 0xff)) /* if temp is 0 -49C is unlikely */
237 			data->sensorsp &= ~SEL_PLACE;
238 	}
239 
240 	if (data->sensorsp & SEL_CORE) {
241 		scfg &= ~SEL_PLACE;	/* Select sensor 0, core1 */
242 		pci_write_config_byte(pdev, REG_TEMP, scfg);
243 		pci_read_config_dword(pdev, REG_TEMP, &temp);
244 		if (!((temp >> 16) & 0xff)) /* if temp is 0 -49C is unlikely */
245 			data->sensorsp &= ~SEL_CORE;
246 	}
247 
248 	data->name = "k8temp";
249 	mutex_init(&data->update_lock);
250 	pci_set_drvdata(pdev, data);
251 
252 	/* Register sysfs hooks */
253 	err = device_create_file(&pdev->dev,
254 			   &sensor_dev_attr_temp1_input.dev_attr);
255 	if (err)
256 		goto exit_remove;
257 
258 	/* sensor can be changed and reports something */
259 	if (data->sensorsp & SEL_PLACE) {
260 		err = device_create_file(&pdev->dev,
261 				   &sensor_dev_attr_temp2_input.dev_attr);
262 		if (err)
263 			goto exit_remove;
264 	}
265 
266 	/* core can be changed and reports something */
267 	if (data->sensorsp & SEL_CORE) {
268 		err = device_create_file(&pdev->dev,
269 				   &sensor_dev_attr_temp3_input.dev_attr);
270 		if (err)
271 			goto exit_remove;
272 		if (data->sensorsp & SEL_PLACE) {
273 			err = device_create_file(&pdev->dev,
274 					   &sensor_dev_attr_temp4_input.
275 					   dev_attr);
276 			if (err)
277 				goto exit_remove;
278 		}
279 	}
280 
281 	err = device_create_file(&pdev->dev, &dev_attr_name);
282 	if (err)
283 		goto exit_remove;
284 
285 	data->hwmon_dev = hwmon_device_register(&pdev->dev);
286 
287 	if (IS_ERR(data->hwmon_dev)) {
288 		err = PTR_ERR(data->hwmon_dev);
289 		goto exit_remove;
290 	}
291 
292 	return 0;
293 
294 exit_remove:
295 	device_remove_file(&pdev->dev,
296 			   &sensor_dev_attr_temp1_input.dev_attr);
297 	device_remove_file(&pdev->dev,
298 			   &sensor_dev_attr_temp2_input.dev_attr);
299 	device_remove_file(&pdev->dev,
300 			   &sensor_dev_attr_temp3_input.dev_attr);
301 	device_remove_file(&pdev->dev,
302 			   &sensor_dev_attr_temp4_input.dev_attr);
303 	device_remove_file(&pdev->dev, &dev_attr_name);
304 	return err;
305 }
306 
307 static void k8temp_remove(struct pci_dev *pdev)
308 {
309 	struct k8temp_data *data = pci_get_drvdata(pdev);
310 
311 	hwmon_device_unregister(data->hwmon_dev);
312 	device_remove_file(&pdev->dev,
313 			   &sensor_dev_attr_temp1_input.dev_attr);
314 	device_remove_file(&pdev->dev,
315 			   &sensor_dev_attr_temp2_input.dev_attr);
316 	device_remove_file(&pdev->dev,
317 			   &sensor_dev_attr_temp3_input.dev_attr);
318 	device_remove_file(&pdev->dev,
319 			   &sensor_dev_attr_temp4_input.dev_attr);
320 	device_remove_file(&pdev->dev, &dev_attr_name);
321 }
322 
323 static struct pci_driver k8temp_driver = {
324 	.name = "k8temp",
325 	.id_table = k8temp_ids,
326 	.probe = k8temp_probe,
327 	.remove = k8temp_remove,
328 };
329 
330 module_pci_driver(k8temp_driver);
331 
332 MODULE_AUTHOR("Rudolf Marek <r.marek@assembler.cz>");
333 MODULE_DESCRIPTION("AMD K8 core temperature monitor");
334 MODULE_LICENSE("GPL");
335