xref: /openbmc/linux/drivers/hwmon/fam15h_power.c (revision 206204a1)
1 /*
2  * fam15h_power.c - AMD Family 15h processor power monitoring
3  *
4  * Copyright (c) 2011 Advanced Micro Devices, Inc.
5  * Author: Andreas Herrmann <herrmann.der.user@googlemail.com>
6  *
7  *
8  * This driver is free software; you can redistribute it and/or
9  * modify it under the terms of the GNU General Public License; either
10  * version 2 of the License, or (at your option) any later version.
11  *
12  * This driver is distributed in the hope that it will be useful,
13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
15  * See the GNU General Public License for more details.
16  *
17  * You should have received a copy of the GNU General Public License
18  * along with this driver; if not, see <http://www.gnu.org/licenses/>.
19  */
20 
21 #include <linux/err.h>
22 #include <linux/hwmon.h>
23 #include <linux/hwmon-sysfs.h>
24 #include <linux/init.h>
25 #include <linux/module.h>
26 #include <linux/pci.h>
27 #include <linux/bitops.h>
28 #include <asm/processor.h>
29 
30 MODULE_DESCRIPTION("AMD Family 15h CPU processor power monitor");
31 MODULE_AUTHOR("Andreas Herrmann <herrmann.der.user@googlemail.com>");
32 MODULE_LICENSE("GPL");
33 
34 /* Family 16h Northbridge's function 4 PCI ID */
35 #define PCI_DEVICE_ID_AMD_16H_NB_F4	0x1534
36 
37 /* D18F3 */
38 #define REG_NORTHBRIDGE_CAP		0xe8
39 
40 /* D18F4 */
41 #define REG_PROCESSOR_TDP		0x1b8
42 
43 /* D18F5 */
44 #define REG_TDP_RUNNING_AVERAGE		0xe0
45 #define REG_TDP_LIMIT3			0xe8
46 
47 struct fam15h_power_data {
48 	struct device *hwmon_dev;
49 	unsigned int tdp_to_watts;
50 	unsigned int base_tdp;
51 	unsigned int processor_pwr_watts;
52 };
53 
54 static ssize_t show_power(struct device *dev,
55 			  struct device_attribute *attr, char *buf)
56 {
57 	u32 val, tdp_limit, running_avg_range;
58 	s32 running_avg_capture;
59 	u64 curr_pwr_watts;
60 	struct pci_dev *f4 = to_pci_dev(dev);
61 	struct fam15h_power_data *data = dev_get_drvdata(dev);
62 
63 	pci_bus_read_config_dword(f4->bus, PCI_DEVFN(PCI_SLOT(f4->devfn), 5),
64 				  REG_TDP_RUNNING_AVERAGE, &val);
65 	running_avg_capture = (val >> 4) & 0x3fffff;
66 	running_avg_capture = sign_extend32(running_avg_capture, 21);
67 	running_avg_range = (val & 0xf) + 1;
68 
69 	pci_bus_read_config_dword(f4->bus, PCI_DEVFN(PCI_SLOT(f4->devfn), 5),
70 				  REG_TDP_LIMIT3, &val);
71 
72 	tdp_limit = val >> 16;
73 	curr_pwr_watts = ((u64)(tdp_limit +
74 				data->base_tdp)) << running_avg_range;
75 	curr_pwr_watts -= running_avg_capture;
76 	curr_pwr_watts *= data->tdp_to_watts;
77 
78 	/*
79 	 * Convert to microWatt
80 	 *
81 	 * power is in Watt provided as fixed point integer with
82 	 * scaling factor 1/(2^16).  For conversion we use
83 	 * (10^6)/(2^16) = 15625/(2^10)
84 	 */
85 	curr_pwr_watts = (curr_pwr_watts * 15625) >> (10 + running_avg_range);
86 	return sprintf(buf, "%u\n", (unsigned int) curr_pwr_watts);
87 }
88 static DEVICE_ATTR(power1_input, S_IRUGO, show_power, NULL);
89 
90 static ssize_t show_power_crit(struct device *dev,
91 			       struct device_attribute *attr, char *buf)
92 {
93 	struct fam15h_power_data *data = dev_get_drvdata(dev);
94 
95 	return sprintf(buf, "%u\n", data->processor_pwr_watts);
96 }
97 static DEVICE_ATTR(power1_crit, S_IRUGO, show_power_crit, NULL);
98 
99 static ssize_t show_name(struct device *dev,
100 			 struct device_attribute *attr, char *buf)
101 {
102 	return sprintf(buf, "fam15h_power\n");
103 }
104 static DEVICE_ATTR(name, S_IRUGO, show_name, NULL);
105 
106 static struct attribute *fam15h_power_attrs[] = {
107 	&dev_attr_power1_input.attr,
108 	&dev_attr_power1_crit.attr,
109 	&dev_attr_name.attr,
110 	NULL
111 };
112 
113 static const struct attribute_group fam15h_power_attr_group = {
114 	.attrs	= fam15h_power_attrs,
115 };
116 
117 static bool fam15h_power_is_internal_node0(struct pci_dev *f4)
118 {
119 	u32 val;
120 
121 	pci_bus_read_config_dword(f4->bus, PCI_DEVFN(PCI_SLOT(f4->devfn), 3),
122 				  REG_NORTHBRIDGE_CAP, &val);
123 	if ((val & BIT(29)) && ((val >> 30) & 3))
124 		return false;
125 
126 	return true;
127 }
128 
129 /*
130  * Newer BKDG versions have an updated recommendation on how to properly
131  * initialize the running average range (was: 0xE, now: 0x9). This avoids
132  * counter saturations resulting in bogus power readings.
133  * We correct this value ourselves to cope with older BIOSes.
134  */
135 static const struct pci_device_id affected_device[] = {
136 	{ PCI_VDEVICE(AMD, PCI_DEVICE_ID_AMD_15H_NB_F4) },
137 	{ 0 }
138 };
139 
140 static void tweak_runavg_range(struct pci_dev *pdev)
141 {
142 	u32 val;
143 
144 	/*
145 	 * let this quirk apply only to the current version of the
146 	 * northbridge, since future versions may change the behavior
147 	 */
148 	if (!pci_match_id(affected_device, pdev))
149 		return;
150 
151 	pci_bus_read_config_dword(pdev->bus,
152 		PCI_DEVFN(PCI_SLOT(pdev->devfn), 5),
153 		REG_TDP_RUNNING_AVERAGE, &val);
154 	if ((val & 0xf) != 0xe)
155 		return;
156 
157 	val &= ~0xf;
158 	val |=  0x9;
159 	pci_bus_write_config_dword(pdev->bus,
160 		PCI_DEVFN(PCI_SLOT(pdev->devfn), 5),
161 		REG_TDP_RUNNING_AVERAGE, val);
162 }
163 
164 #ifdef CONFIG_PM
165 static int fam15h_power_resume(struct pci_dev *pdev)
166 {
167 	tweak_runavg_range(pdev);
168 	return 0;
169 }
170 #else
171 #define fam15h_power_resume NULL
172 #endif
173 
174 static void fam15h_power_init_data(struct pci_dev *f4,
175 					     struct fam15h_power_data *data)
176 {
177 	u32 val;
178 	u64 tmp;
179 
180 	pci_read_config_dword(f4, REG_PROCESSOR_TDP, &val);
181 	data->base_tdp = val >> 16;
182 	tmp = val & 0xffff;
183 
184 	pci_bus_read_config_dword(f4->bus, PCI_DEVFN(PCI_SLOT(f4->devfn), 5),
185 				  REG_TDP_LIMIT3, &val);
186 
187 	data->tdp_to_watts = ((val & 0x3ff) << 6) | ((val >> 10) & 0x3f);
188 	tmp *= data->tdp_to_watts;
189 
190 	/* result not allowed to be >= 256W */
191 	if ((tmp >> 16) >= 256)
192 		dev_warn(&f4->dev,
193 			 "Bogus value for ProcessorPwrWatts (processor_pwr_watts>=%u)\n",
194 			 (unsigned int) (tmp >> 16));
195 
196 	/* convert to microWatt */
197 	data->processor_pwr_watts = (tmp * 15625) >> 10;
198 }
199 
200 static int fam15h_power_probe(struct pci_dev *pdev,
201 					const struct pci_device_id *id)
202 {
203 	struct fam15h_power_data *data;
204 	struct device *dev = &pdev->dev;
205 	int err;
206 
207 	/*
208 	 * though we ignore every other northbridge, we still have to
209 	 * do the tweaking on _each_ node in MCM processors as the counters
210 	 * are working hand-in-hand
211 	 */
212 	tweak_runavg_range(pdev);
213 
214 	if (!fam15h_power_is_internal_node0(pdev))
215 		return -ENODEV;
216 
217 	data = devm_kzalloc(dev, sizeof(struct fam15h_power_data), GFP_KERNEL);
218 	if (!data)
219 		return -ENOMEM;
220 
221 	fam15h_power_init_data(pdev, data);
222 
223 	dev_set_drvdata(dev, data);
224 	err = sysfs_create_group(&dev->kobj, &fam15h_power_attr_group);
225 	if (err)
226 		return err;
227 
228 	data->hwmon_dev = hwmon_device_register(dev);
229 	if (IS_ERR(data->hwmon_dev)) {
230 		err = PTR_ERR(data->hwmon_dev);
231 		goto exit_remove_group;
232 	}
233 
234 	return 0;
235 
236 exit_remove_group:
237 	sysfs_remove_group(&dev->kobj, &fam15h_power_attr_group);
238 	return err;
239 }
240 
241 static void fam15h_power_remove(struct pci_dev *pdev)
242 {
243 	struct device *dev;
244 	struct fam15h_power_data *data;
245 
246 	dev = &pdev->dev;
247 	data = dev_get_drvdata(dev);
248 	hwmon_device_unregister(data->hwmon_dev);
249 	sysfs_remove_group(&dev->kobj, &fam15h_power_attr_group);
250 }
251 
252 static const struct pci_device_id fam15h_power_id_table[] = {
253 	{ PCI_VDEVICE(AMD, PCI_DEVICE_ID_AMD_15H_NB_F4) },
254 	{ PCI_VDEVICE(AMD, PCI_DEVICE_ID_AMD_16H_NB_F4) },
255 	{}
256 };
257 MODULE_DEVICE_TABLE(pci, fam15h_power_id_table);
258 
259 static struct pci_driver fam15h_power_driver = {
260 	.name = "fam15h_power",
261 	.id_table = fam15h_power_id_table,
262 	.probe = fam15h_power_probe,
263 	.remove = fam15h_power_remove,
264 	.resume = fam15h_power_resume,
265 };
266 
267 module_pci_driver(fam15h_power_driver);
268