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