summaryrefslogtreecommitdiff
path: root/drivers/hwmon/k8temp.c
blob: 2b80ac410cd1b91f75eb23fb9ec6bacbb33fb020 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * k8temp.c - Linux kernel module for hardware monitoring
 *
 * Copyright (C) 2006 Rudolf Marek <r.marek@assembler.cz>
 *
 * Inspired from the w83785 and amd756 drivers.
 */

#include <linux/module.h>
#include <linux/init.h>
#include <linux/slab.h>
#include <linux/pci.h>
#include <linux/hwmon.h>
#include <linux/err.h>
#include <linux/mutex.h>
#include <asm/processor.h>

#define TEMP_FROM_REG(val)	(((((val) >> 16) & 0xff) - 49) * 1000)
#define REG_TEMP	0xe4
#define SEL_PLACE	0x40
#define SEL_CORE	0x04

struct k8temp_data {
	struct mutex update_lock;

	/* registers values */
	u8 sensorsp;		/* sensor presence bits - SEL_CORE, SEL_PLACE */
	u8 swap_core_select;    /* meaning of SEL_CORE is inverted */
	u32 temp_offset;
};

static const struct pci_device_id k8temp_ids[] = {
	{ PCI_DEVICE(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_K8_NB_MISC) },
	{ 0 },
};
MODULE_DEVICE_TABLE(pci, k8temp_ids);

static int is_rev_g_desktop(u8 model)
{
	u32 brandidx;

	if (model < 0x69)
		return 0;

	if (model == 0xc1 || model == 0x6c || model == 0x7c)
		return 0;

	/*
	 * Differentiate between AM2 and ASB1.
	 * See "Constructing the processor Name String" in "Revision
	 * Guide for AMD NPT Family 0Fh Processors" (33610).
	 */
	brandidx = cpuid_ebx(0x80000001);
	brandidx = (brandidx >> 9) & 0x1f;

	/* Single core */
	if ((model == 0x6f || model == 0x7f) &&
	    (brandidx == 0x7 || brandidx == 0x9 || brandidx == 0xc))
		return 0;

	/* Dual core */
	if (model == 0x6b &&
	    (brandidx == 0xb || brandidx == 0xc))
		return 0;

	return 1;
}

static umode_t
k8temp_is_visible(const void *drvdata, enum hwmon_sensor_types type,
		  u32 attr, int channel)
{
	const struct k8temp_data *data = drvdata;

	if ((channel & 1) && !(data->sensorsp & SEL_PLACE))
		return 0;

	if ((channel & 2) && !(data->sensorsp & SEL_CORE))
		return 0;

	return 0444;
}

static int
k8temp_read(struct device *dev, enum hwmon_sensor_types type,
	    u32 attr, int channel, long *val)
{
	struct k8temp_data *data = dev_get_drvdata(dev);
	struct pci_dev *pdev = to_pci_dev(dev->parent);
	int core, place;
	u32 temp;
	u8 tmp;

	core = (channel >> 1) & 1;
	place = channel & 1;

	core ^= data->swap_core_select;

	mutex_lock(&data->update_lock);
	pci_read_config_byte(pdev, REG_TEMP, &tmp);
	tmp &= ~(SEL_PLACE | SEL_CORE);
	if (core)
		tmp |= SEL_CORE;
	if (place)
		tmp |= SEL_PLACE;
	pci_write_config_byte(pdev, REG_TEMP, tmp);
	pci_read_config_dword(pdev, REG_TEMP, &temp);
	mutex_unlock(&data->update_lock);

	*val = TEMP_FROM_REG(temp) + data->temp_offset;

	return 0;
}

static const struct hwmon_ops k8temp_ops = {
	.is_visible = k8temp_is_visible,
	.read = k8temp_read,
};

static const struct hwmon_channel_info * const k8temp_info[] = {
	HWMON_CHANNEL_INFO(temp,
		HWMON_T_INPUT, HWMON_T_INPUT, HWMON_T_INPUT, HWMON_T_INPUT),
	NULL
};

static const struct hwmon_chip_info k8temp_chip_info = {
	.ops = &k8temp_ops,
	.info = k8temp_info,
};

static int k8temp_probe(struct pci_dev *pdev,
				  const struct pci_device_id *id)
{
	u8 scfg;
	u32 temp;
	u8 model, stepping;
	struct k8temp_data *data;
	struct device *hwmon_dev;

	data = devm_kzalloc(&pdev->dev, sizeof(struct k8temp_data), GFP_KERNEL);
	if (!data)
		return -ENOMEM;

	model = boot_cpu_data.x86_model;
	stepping = boot_cpu_data.x86_stepping;

	/* feature available since SH-C0, exclude older revisions */
	if ((model == 4 && stepping == 0) ||
	    (model == 5 && stepping <= 1))
		return -ENODEV;

	/*
	 * AMD NPT family 0fh, i.e. RevF and RevG:
	 * meaning of SEL_CORE bit is inverted
	 */
	if (model >= 0x40) {
		data->swap_core_select = 1;
		dev_warn(&pdev->dev,
			 "Temperature readouts might be wrong - check erratum #141\n");
	}

	/*
	 * RevG desktop CPUs (i.e. no socket S1G1 or ASB1 parts) need
	 * additional offset, otherwise reported temperature is below
	 * ambient temperature
	 */
	if (is_rev_g_desktop(model))
		data->temp_offset = 21000;

	pci_read_config_byte(pdev, REG_TEMP, &scfg);
	scfg &= ~(SEL_PLACE | SEL_CORE);	/* Select sensor 0, core0 */
	pci_write_config_byte(pdev, REG_TEMP, scfg);
	pci_read_config_byte(pdev, REG_TEMP, &scfg);

	if (scfg & (SEL_PLACE | SEL_CORE)) {
		dev_err(&pdev->dev, "Configuration bit(s) stuck at 1!\n");
		return -ENODEV;
	}

	scfg |= (SEL_PLACE | SEL_CORE);
	pci_write_config_byte(pdev, REG_TEMP, scfg);

	/* now we know if we can change core and/or sensor */
	pci_read_config_byte(pdev, REG_TEMP, &data->sensorsp);

	if (data->sensorsp & SEL_PLACE) {
		scfg &= ~SEL_CORE;	/* Select sensor 1, core0 */
		pci_write_config_byte(pdev, REG_TEMP, scfg);
		pci_read_config_dword(pdev, REG_TEMP, &temp);
		scfg |= SEL_CORE;	/* prepare for next selection */
		if (!((temp >> 16) & 0xff)) /* if temp is 0 -49C is unlikely */
			data->sensorsp &= ~SEL_PLACE;
	}

	if (data->sensorsp & SEL_CORE) {
		scfg &= ~SEL_PLACE;	/* Select sensor 0, core1 */
		pci_write_config_byte(pdev, REG_TEMP, scfg);
		pci_read_config_dword(pdev, REG_TEMP, &temp);
		if (!((temp >> 16) & 0xff)) /* if temp is 0 -49C is unlikely */
			data->sensorsp &= ~SEL_CORE;
	}

	mutex_init(&data->update_lock);

	hwmon_dev = devm_hwmon_device_register_with_info(&pdev->dev,
							 "k8temp",
							 data,
							 &k8temp_chip_info,
							 NULL);

	return PTR_ERR_OR_ZERO(hwmon_dev);
}

static struct pci_driver k8temp_driver = {
	.name = "k8temp",
	.id_table = k8temp_ids,
	.probe = k8temp_probe,
};

module_pci_driver(k8temp_driver);

MODULE_AUTHOR("Rudolf Marek <r.marek@assembler.cz>");
MODULE_DESCRIPTION("AMD K8 core temperature monitor");
MODULE_LICENSE("GPL");