2 * fam15h_power.c - AMD Family 15h processor power monitoring
4 * Copyright (c) 2011 Advanced Micro Devices, Inc.
5 * Author: Andreas Herrmann <andreas.herrmann3@amd.com>
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.
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.
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/>.
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>
30 MODULE_DESCRIPTION("AMD Family 15h CPU processor power monitor");
31 MODULE_AUTHOR("Andreas Herrmann <andreas.herrmann3@amd.com>");
32 MODULE_LICENSE("GPL");
35 #define REG_NORTHBRIDGE_CAP 0xe8
38 #define REG_PROCESSOR_TDP 0x1b8
41 #define REG_TDP_RUNNING_AVERAGE 0xe0
42 #define REG_TDP_LIMIT3 0xe8
44 struct fam15h_power_data {
45 struct device *hwmon_dev;
46 unsigned int tdp_to_watts;
47 unsigned int base_tdp;
48 unsigned int processor_pwr_watts;
51 static ssize_t show_power(struct device *dev,
52 struct device_attribute *attr, char *buf)
54 u32 val, tdp_limit, running_avg_range;
55 s32 running_avg_capture;
57 struct pci_dev *f4 = to_pci_dev(dev);
58 struct fam15h_power_data *data = dev_get_drvdata(dev);
60 pci_bus_read_config_dword(f4->bus, PCI_DEVFN(PCI_SLOT(f4->devfn), 5),
61 REG_TDP_RUNNING_AVERAGE, &val);
62 running_avg_capture = (val >> 4) & 0x3fffff;
63 running_avg_capture = sign_extend32(running_avg_capture, 21);
64 running_avg_range = (val & 0xf) + 1;
66 pci_bus_read_config_dword(f4->bus, PCI_DEVFN(PCI_SLOT(f4->devfn), 5),
67 REG_TDP_LIMIT3, &val);
69 tdp_limit = val >> 16;
70 curr_pwr_watts = (tdp_limit + data->base_tdp) << running_avg_range;
71 curr_pwr_watts -= running_avg_capture;
72 curr_pwr_watts *= data->tdp_to_watts;
75 * Convert to microWatt
77 * power is in Watt provided as fixed point integer with
78 * scaling factor 1/(2^16). For conversion we use
79 * (10^6)/(2^16) = 15625/(2^10)
81 curr_pwr_watts = (curr_pwr_watts * 15625) >> (10 + running_avg_range);
82 return sprintf(buf, "%u\n", (unsigned int) curr_pwr_watts);
84 static DEVICE_ATTR(power1_input, S_IRUGO, show_power, NULL);
86 static ssize_t show_power_crit(struct device *dev,
87 struct device_attribute *attr, char *buf)
89 struct fam15h_power_data *data = dev_get_drvdata(dev);
91 return sprintf(buf, "%u\n", data->processor_pwr_watts);
93 static DEVICE_ATTR(power1_crit, S_IRUGO, show_power_crit, NULL);
95 static ssize_t show_name(struct device *dev,
96 struct device_attribute *attr, char *buf)
98 return sprintf(buf, "fam15h_power\n");
100 static DEVICE_ATTR(name, S_IRUGO, show_name, NULL);
102 static struct attribute *fam15h_power_attrs[] = {
103 &dev_attr_power1_input.attr,
104 &dev_attr_power1_crit.attr,
109 static const struct attribute_group fam15h_power_attr_group = {
110 .attrs = fam15h_power_attrs,
113 static bool __devinit fam15h_power_is_internal_node0(struct pci_dev *f4)
117 pci_bus_read_config_dword(f4->bus, PCI_DEVFN(PCI_SLOT(f4->devfn), 3),
118 REG_NORTHBRIDGE_CAP, &val);
119 if ((val & BIT(29)) && ((val >> 30) & 3))
126 * Newer BKDG versions have an updated recommendation on how to properly
127 * initialize the running average range (was: 0xE, now: 0x9). This avoids
128 * counter saturations resulting in bogus power readings.
129 * We correct this value ourselves to cope with older BIOSes.
131 static DEFINE_PCI_DEVICE_TABLE(affected_device) = {
132 { PCI_VDEVICE(AMD, PCI_DEVICE_ID_AMD_15H_NB_F4) },
136 static void __devinit tweak_runavg_range(struct pci_dev *pdev)
141 * let this quirk apply only to the current version of the
142 * northbridge, since future versions may change the behavior
144 if (!pci_match_id(affected_device, pdev))
147 pci_bus_read_config_dword(pdev->bus,
148 PCI_DEVFN(PCI_SLOT(pdev->devfn), 5),
149 REG_TDP_RUNNING_AVERAGE, &val);
150 if ((val & 0xf) != 0xe)
155 pci_bus_write_config_dword(pdev->bus,
156 PCI_DEVFN(PCI_SLOT(pdev->devfn), 5),
157 REG_TDP_RUNNING_AVERAGE, val);
160 static void __devinit fam15h_power_init_data(struct pci_dev *f4,
161 struct fam15h_power_data *data)
166 pci_read_config_dword(f4, REG_PROCESSOR_TDP, &val);
167 data->base_tdp = val >> 16;
170 pci_bus_read_config_dword(f4->bus, PCI_DEVFN(PCI_SLOT(f4->devfn), 5),
171 REG_TDP_LIMIT3, &val);
173 data->tdp_to_watts = ((val & 0x3ff) << 6) | ((val >> 10) & 0x3f);
174 tmp *= data->tdp_to_watts;
176 /* result not allowed to be >= 256W */
177 if ((tmp >> 16) >= 256)
178 dev_warn(&f4->dev, "Bogus value for ProcessorPwrWatts "
179 "(processor_pwr_watts>=%u)\n",
180 (unsigned int) (tmp >> 16));
182 /* convert to microWatt */
183 data->processor_pwr_watts = (tmp * 15625) >> 10;
186 static int __devinit fam15h_power_probe(struct pci_dev *pdev,
187 const struct pci_device_id *id)
189 struct fam15h_power_data *data;
194 * though we ignore every other northbridge, we still have to
195 * do the tweaking on _each_ node in MCM processors as the counters
196 * are working hand-in-hand
198 tweak_runavg_range(pdev);
200 if (!fam15h_power_is_internal_node0(pdev)) {
205 data = kzalloc(sizeof(struct fam15h_power_data), GFP_KERNEL);
210 fam15h_power_init_data(pdev, data);
213 dev_set_drvdata(dev, data);
214 err = sysfs_create_group(&dev->kobj, &fam15h_power_attr_group);
218 data->hwmon_dev = hwmon_device_register(dev);
219 if (IS_ERR(data->hwmon_dev)) {
220 err = PTR_ERR(data->hwmon_dev);
221 goto exit_remove_group;
227 sysfs_remove_group(&dev->kobj, &fam15h_power_attr_group);
234 static void __devexit fam15h_power_remove(struct pci_dev *pdev)
237 struct fam15h_power_data *data;
240 data = dev_get_drvdata(dev);
241 hwmon_device_unregister(data->hwmon_dev);
242 sysfs_remove_group(&dev->kobj, &fam15h_power_attr_group);
243 dev_set_drvdata(dev, NULL);
247 static DEFINE_PCI_DEVICE_TABLE(fam15h_power_id_table) = {
248 { PCI_VDEVICE(AMD, PCI_DEVICE_ID_AMD_15H_NB_F4) },
251 MODULE_DEVICE_TABLE(pci, fam15h_power_id_table);
253 static struct pci_driver fam15h_power_driver = {
254 .name = "fam15h_power",
255 .id_table = fam15h_power_id_table,
256 .probe = fam15h_power_probe,
257 .remove = __devexit_p(fam15h_power_remove),
260 static int __init fam15h_power_init(void)
262 return pci_register_driver(&fam15h_power_driver);
265 static void __exit fam15h_power_exit(void)
267 pci_unregister_driver(&fam15h_power_driver);
270 module_init(fam15h_power_init)
271 module_exit(fam15h_power_exit)