drivers/hwmon/fam15h_power.c

   1 /*
   2  * fam15h_power.c - AMD Family 15h processor power monitoring
   3  *
   4  * Copyright (c) 2011 Advanced Micro Devices, Inc.
   5  * Author: Andreas Herrmann <andreas.herrmann3@amd.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 <andreas.herrmann3@amd.com>");
  32 MODULE_LICENSE("GPL");
  33
  34 /* D18F3 */
  35 #define REG_NORTHBRIDGE_CAP             0xe8
  36
  37 /* D18F4 */
  38 #define REG_PROCESSOR_TDP               0x1b8
  39
  40 /* D18F5 */
  41 #define REG_TDP_RUNNING_AVERAGE         0xe0
  42 #define REG_TDP_LIMIT3                  0xe8
  43
  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;
  49 };
  50
  51 static ssize_t show_power(struct device *dev,
  52                           struct device_attribute *attr, char *buf)
  53 {
  54         u32 val, tdp_limit, running_avg_range;
  55         s32 running_avg_capture;
  56         u64 curr_pwr_watts;
  57         struct pci_dev *f4 = to_pci_dev(dev);
  58         struct fam15h_power_data *data = dev_get_drvdata(dev);
  59
  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;
  65
  66         pci_bus_read_config_dword(f4->bus, PCI_DEVFN(PCI_SLOT(f4->devfn), 5),
  67                                   REG_TDP_LIMIT3, &val);
  68
  69         tdp_limit = val >> 16;
  70         curr_pwr_watts = tdp_limit + data->base_tdp -
  71                 (s32)(running_avg_capture >> (running_avg_range + 1));
  72         curr_pwr_watts *= data->tdp_to_watts;
  73
  74         /*
  75          * Convert to microWatt
  76          *
  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)
  80          */
  81         curr_pwr_watts = (curr_pwr_watts * 15625) >> 10;
  82         return sprintf(buf, "%u\n", (unsigned int) curr_pwr_watts);
  83 }
  84 static DEVICE_ATTR(power1_input, S_IRUGO, show_power, NULL);
  85
  86 static ssize_t show_power_crit(struct device *dev,
  87                                struct device_attribute *attr, char *buf)
  88 {
  89         struct fam15h_power_data *data = dev_get_drvdata(dev);
  90
  91         return sprintf(buf, "%u\n", data->processor_pwr_watts);
  92 }
  93 static DEVICE_ATTR(power1_crit, S_IRUGO, show_power_crit, NULL);
  94
  95 static ssize_t show_name(struct device *dev,
  96                          struct device_attribute *attr, char *buf)
  97 {
  98         return sprintf(buf, "fam15h_power\n");
  99 }
 100 static DEVICE_ATTR(name, S_IRUGO, show_name, NULL);
 101
 102 static struct attribute *fam15h_power_attrs[] = {
 103         &dev_attr_power1_input.attr,
 104         &dev_attr_power1_crit.attr,
 105         &dev_attr_name.attr,
 106         NULL
 107 };
 108
 109 static const struct attribute_group fam15h_power_attr_group = {
 110         .attrs  = fam15h_power_attrs,
 111 };
 112
 113 static bool __devinit fam15h_power_is_internal_node0(struct pci_dev *f4)
 114 {
 115         u32 val;
 116
 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))
 120                 return false;
 121
 122         return true;
 123 }
 124
 125 /*
 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.
 130  */
 131 static DEFINE_PCI_DEVICE_TABLE(affected_device) = {
 132         { PCI_VDEVICE(AMD, PCI_DEVICE_ID_AMD_15H_NB_F4) },
 133         { 0 }
 134 };
 135
 136 static void __devinit tweak_runavg_range(struct pci_dev *pdev)
 137 {
 138         u32 val;
 139
 140         /*
 141          * let this quirk apply only to the current version of the
 142          * northbridge, since future versions may change the behavior
 143          */
 144         if (!pci_match_id(affected_device, pdev))
 145                 return;
 146
 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)
 151                 return;
 152
 153         val &= ~0xf;
 154         val |=  0x9;
 155         pci_bus_write_config_dword(pdev->bus,
 156                 PCI_DEVFN(PCI_SLOT(pdev->devfn), 5),
 157                 REG_TDP_RUNNING_AVERAGE, val);
 158 }
 159
 160 static void __devinit fam15h_power_init_data(struct pci_dev *f4,
 161                                              struct fam15h_power_data *data)
 162 {
 163         u32 val;
 164         u64 tmp;
 165
 166         pci_read_config_dword(f4, REG_PROCESSOR_TDP, &val);
 167         data->base_tdp = val >> 16;
 168         tmp = val & 0xffff;
 169
 170         pci_bus_read_config_dword(f4->bus, PCI_DEVFN(PCI_SLOT(f4->devfn), 5),
 171                                   REG_TDP_LIMIT3, &val);
 172
 173         data->tdp_to_watts = ((val & 0x3ff) << 6) | ((val >> 10) & 0x3f);
 174         tmp *= data->tdp_to_watts;
 175
 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));
 181
 182         /* convert to microWatt */
 183         data->processor_pwr_watts = (tmp * 15625) >> 10;
 184 }
 185
 186 static int __devinit fam15h_power_probe(struct pci_dev *pdev,
 187                                         const struct pci_device_id *id)
 188 {
 189         struct fam15h_power_data *data;
 190         struct device *dev;
 191         int err;
 192
 193         /*
 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
 197          */
 198         tweak_runavg_range(pdev);
 199
 200         if (!fam15h_power_is_internal_node0(pdev)) {
 201                 err = -ENODEV;
 202                 goto exit;
 203         }
 204
 205         data = kzalloc(sizeof(struct fam15h_power_data), GFP_KERNEL);
 206         if (!data) {
 207                 err = -ENOMEM;
 208                 goto exit;
 209         }
 210         fam15h_power_init_data(pdev, data);
 211         dev = &pdev->dev;
 212
 213         dev_set_drvdata(dev, data);
 214         err = sysfs_create_group(&dev->kobj, &fam15h_power_attr_group);
 215         if (err)
 216                 goto exit_free_data;
 217
 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;
 222         }
 223
 224         return 0;
 225
 226 exit_remove_group:
 227         sysfs_remove_group(&dev->kobj, &fam15h_power_attr_group);
 228 exit_free_data:
 229         kfree(data);
 230 exit:
 231         return err;
 232 }
 233
 234 static void __devexit fam15h_power_remove(struct pci_dev *pdev)
 235 {
 236         struct device *dev;
 237         struct fam15h_power_data *data;
 238
 239         dev = &pdev->dev;
 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);
 244         kfree(data);
 245 }
 246
 247 static DEFINE_PCI_DEVICE_TABLE(fam15h_power_id_table) = {
 248         { PCI_VDEVICE(AMD, PCI_DEVICE_ID_AMD_15H_NB_F4) },
 249         {}
 250 };
 251 MODULE_DEVICE_TABLE(pci, fam15h_power_id_table);
 252
 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),
 258 };
 259
 260 static int __init fam15h_power_init(void)
 261 {
 262         return pci_register_driver(&fam15h_power_driver);
 263 }
 264
 265 static void __exit fam15h_power_exit(void)
 266 {
 267         pci_unregister_driver(&fam15h_power_driver);
 268 }
 269
 270 module_init(fam15h_power_init)
 271 module_exit(fam15h_power_exit)