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 /* 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 = (tdp_limit + data->base_tdp) << running_avg_range;
  74         curr_pwr_watts -= running_avg_capture;
  75         curr_pwr_watts *= data->tdp_to_watts;
  76
  77         /*
  78          * Convert to microWatt
  79          *
  80          * power is in Watt provided as fixed point integer with
  81          * scaling factor 1/(2^16).  For conversion we use
  82          * (10^6)/(2^16) = 15625/(2^10)
  83          */
  84         curr_pwr_watts = (curr_pwr_watts * 15625) >> (10 + running_avg_range);
  85         return sprintf(buf, "%u\n", (unsigned int) curr_pwr_watts);
  86 }
  87 static DEVICE_ATTR(power1_input, S_IRUGO, show_power, NULL);
  88
  89 static ssize_t show_power_crit(struct device *dev,
  90                                struct device_attribute *attr, char *buf)
  91 {
  92         struct fam15h_power_data *data = dev_get_drvdata(dev);
  93
  94         return sprintf(buf, "%u\n", data->processor_pwr_watts);
  95 }
  96 static DEVICE_ATTR(power1_crit, S_IRUGO, show_power_crit, NULL);
  97
  98 static ssize_t show_name(struct device *dev,
  99                          struct device_attribute *attr, char *buf)
 100 {
 101         return sprintf(buf, "fam15h_power\n");
 102 }
 103 static DEVICE_ATTR(name, S_IRUGO, show_name, NULL);
 104
 105 static struct attribute *fam15h_power_attrs[] = {
 106         &dev_attr_power1_input.attr,
 107         &dev_attr_power1_crit.attr,
 108         &dev_attr_name.attr,
 109         NULL
 110 };
 111
 112 static const struct attribute_group fam15h_power_attr_group = {
 113         .attrs  = fam15h_power_attrs,
 114 };
 115
 116 static bool __devinit fam15h_power_is_internal_node0(struct pci_dev *f4)
 117 {
 118         u32 val;
 119
 120         pci_bus_read_config_dword(f4->bus, PCI_DEVFN(PCI_SLOT(f4->devfn), 3),
 121                                   REG_NORTHBRIDGE_CAP, &val);
 122         if ((val & BIT(29)) && ((val >> 30) & 3))
 123                 return false;
 124
 125         return true;
 126 }
 127
 128 /*
 129  * Newer BKDG versions have an updated recommendation on how to properly
 130  * initialize the running average range (was: 0xE, now: 0x9). This avoids
 131  * counter saturations resulting in bogus power readings.
 132  * We correct this value ourselves to cope with older BIOSes.
 133  */
 134 static const struct pci_device_id affected_device[] = {
 135         { PCI_VDEVICE(AMD, PCI_DEVICE_ID_AMD_15H_NB_F4) },
 136         { 0 }
 137 };
 138
 139 static void tweak_runavg_range(struct pci_dev *pdev)
 140 {
 141         u32 val;
 142
 143         /*
 144          * let this quirk apply only to the current version of the
 145          * northbridge, since future versions may change the behavior
 146          */
 147         if (!pci_match_id(affected_device, pdev))
 148                 return;
 149
 150         pci_bus_read_config_dword(pdev->bus,
 151                 PCI_DEVFN(PCI_SLOT(pdev->devfn), 5),
 152                 REG_TDP_RUNNING_AVERAGE, &val);
 153         if ((val & 0xf) != 0xe)
 154                 return;
 155
 156         val &= ~0xf;
 157         val |=  0x9;
 158         pci_bus_write_config_dword(pdev->bus,
 159                 PCI_DEVFN(PCI_SLOT(pdev->devfn), 5),
 160                 REG_TDP_RUNNING_AVERAGE, val);
 161 }
 162
 163 #ifdef CONFIG_PM
 164 static int fam15h_power_resume(struct pci_dev *pdev)
 165 {
 166         tweak_runavg_range(pdev);
 167         return 0;
 168 }
 169 #else
 170 #define fam15h_power_resume NULL
 171 #endif
 172
 173 static void __devinit fam15h_power_init_data(struct pci_dev *f4,
 174                                              struct fam15h_power_data *data)
 175 {
 176         u32 val;
 177         u64 tmp;
 178
 179         pci_read_config_dword(f4, REG_PROCESSOR_TDP, &val);
 180         data->base_tdp = val >> 16;
 181         tmp = val & 0xffff;
 182
 183         pci_bus_read_config_dword(f4->bus, PCI_DEVFN(PCI_SLOT(f4->devfn), 5),
 184                                   REG_TDP_LIMIT3, &val);
 185
 186         data->tdp_to_watts = ((val & 0x3ff) << 6) | ((val >> 10) & 0x3f);
 187         tmp *= data->tdp_to_watts;
 188
 189         /* result not allowed to be >= 256W */
 190         if ((tmp >> 16) >= 256)
 191                 dev_warn(&f4->dev, "Bogus value for ProcessorPwrWatts "
 192                          "(processor_pwr_watts>=%u)\n",
 193                          (unsigned int) (tmp >> 16));
 194
 195         /* convert to microWatt */
 196         data->processor_pwr_watts = (tmp * 15625) >> 10;
 197 }
 198
 199 static int __devinit fam15h_power_probe(struct pci_dev *pdev,
 200                                         const struct pci_device_id *id)
 201 {
 202         struct fam15h_power_data *data;
 203         struct device *dev;
 204         int err;
 205
 206         /*
 207          * though we ignore every other northbridge, we still have to
 208          * do the tweaking on _each_ node in MCM processors as the counters
 209          * are working hand-in-hand
 210          */
 211         tweak_runavg_range(pdev);
 212
 213         if (!fam15h_power_is_internal_node0(pdev)) {
 214                 err = -ENODEV;
 215                 goto exit;
 216         }
 217
 218         data = kzalloc(sizeof(struct fam15h_power_data), GFP_KERNEL);
 219         if (!data) {
 220                 err = -ENOMEM;
 221                 goto exit;
 222         }
 223         fam15h_power_init_data(pdev, data);
 224         dev = &pdev->dev;
 225
 226         dev_set_drvdata(dev, data);
 227         err = sysfs_create_group(&dev->kobj, &fam15h_power_attr_group);
 228         if (err)
 229                 goto exit_free_data;
 230
 231         data->hwmon_dev = hwmon_device_register(dev);
 232         if (IS_ERR(data->hwmon_dev)) {
 233                 err = PTR_ERR(data->hwmon_dev);
 234                 goto exit_remove_group;
 235         }
 236
 237         return 0;
 238
 239 exit_remove_group:
 240         sysfs_remove_group(&dev->kobj, &fam15h_power_attr_group);
 241 exit_free_data:
 242         kfree(data);
 243 exit:
 244         return err;
 245 }
 246
 247 static void __devexit fam15h_power_remove(struct pci_dev *pdev)
 248 {
 249         struct device *dev;
 250         struct fam15h_power_data *data;
 251
 252         dev = &pdev->dev;
 253         data = dev_get_drvdata(dev);
 254         hwmon_device_unregister(data->hwmon_dev);
 255         sysfs_remove_group(&dev->kobj, &fam15h_power_attr_group);
 256         dev_set_drvdata(dev, NULL);
 257         kfree(data);
 258 }
 259
 260 static DEFINE_PCI_DEVICE_TABLE(fam15h_power_id_table) = {
 261         { PCI_VDEVICE(AMD, PCI_DEVICE_ID_AMD_15H_NB_F4) },
 262         { PCI_VDEVICE(AMD, PCI_DEVICE_ID_AMD_16H_NB_F4) },
 263         {}
 264 };
 265 MODULE_DEVICE_TABLE(pci, fam15h_power_id_table);
 266
 267 static struct pci_driver fam15h_power_driver = {
 268         .name = "fam15h_power",
 269         .id_table = fam15h_power_id_table,
 270         .probe = fam15h_power_probe,
 271         .remove = __devexit_p(fam15h_power_remove),
 272         .resume = fam15h_power_resume,
 273 };
 274
 275 static int __init fam15h_power_init(void)
 276 {
 277         return pci_register_driver(&fam15h_power_driver);
 278 }
 279
 280 static void __exit fam15h_power_exit(void)
 281 {
 282         pci_unregister_driver(&fam15h_power_driver);
 283 }
 284
 285 module_init(fam15h_power_init)
 286 module_exit(fam15h_power_exit)