/*
* fam15h_power.c - AMD Family 15h processor power monitoring
*
* Copyright (c) 2011 Advanced Micro Devices, Inc.
* Author: Andreas Herrmann <andreas.herrmann3@amd.com>
*
*
* This driver is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License; either
* version 2 of the License, or (at your option) any later version.
*
* This driver is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
* See the GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this driver; if not, see <http://www.gnu.org/licenses/>.
*/
#include <linux/err.h>
#include <linux/hwmon.h>
#include <linux/hwmon-sysfs.h>
#include <linux/init.h>
#include <linux/module.h>
#include <linux/pci.h>
#include <linux/bitops.h>
#include <asm/processor.h>
MODULE_DESCRIPTION("AMD Family 15h CPU processor power monitor");
MODULE_AUTHOR("Andreas Herrmann <andreas.herrmann3@amd.com>");
MODULE_LICENSE("GPL");
/* D18F3 */
#define REG_NORTHBRIDGE_CAP 0xe8
/* D18F4 */
#define REG_PROCESSOR_TDP 0x1b8
/* D18F5 */
#define REG_TDP_RUNNING_AVERAGE 0xe0
#define REG_TDP_LIMIT3 0xe8
struct fam15h_power_data {
struct device *hwmon_dev;
unsigned int tdp_to_watts;
unsigned int base_tdp;
unsigned int processor_pwr_watts;
};
static ssize_t show_power(struct device *dev,
struct device_attribute *attr, char *buf)
{
u32 val, tdp_limit, running_avg_range;
s32 running_avg_capture;
u64 curr_pwr_watts;
struct pci_dev *f4 = to_pci_dev(dev);
struct fam15h_power_data *data = dev_get_drvdata(dev);
pci_bus_read_config_dword(f4->bus, PCI_DEVFN(PCI_SLOT(f4->devfn), 5),
REG_TDP_RUNNING_AVERAGE, &val);
running_avg_capture = (val >> 4) & 0x3fffff;
running_avg_capture = sign_extend32(running_avg_capture, 21);
running_avg_range = (val & 0xf) + 1;
pci_bus_read_config_dword(f4->bus, PCI_DEVFN(PCI_SLOT(f4->devfn), 5),
REG_TDP_LIMIT3, &val);
tdp_limit = val >> 16;
curr_pwr_watts = (tdp_limit + data->base_tdp) << running_avg_range;
curr_pwr_watts -= running_avg_capture;
curr_pwr_watts *= data->tdp_to_watts;
/*
* Convert to microWatt
*
* power is in Watt provided as fixed point integer with
* scaling factor 1/(2^16). For conversion we use
* (10^6)/(2^16) = 15625/(2^10)
*/
curr_pwr_watts = (curr_pwr_watts * 15625) >> (10 + running_avg_range);
return sprintf(buf, "%u\n", (unsigned int) curr_pwr_watts);
}
static DEVICE_ATTR(power1_input, S_IRUGO, show_power, NULL);
static ssize_t show_power_crit(struct device *dev,
struct device_attribute *attr, char *buf)
{
struct fam15h_power_data *data = dev_get_drvdata(dev);
return sprintf(buf, "%u\n", data->processor_pwr_watts);
}
static DEVICE_ATTR(power1_crit, S_IRUGO, show_power_crit, NULL);
static ssize_t show_name(struct device *dev,
struct device_attribute *attr, char *buf)
{
return sprintf(buf, "fam15h_power\n");
}
static DEVICE_ATTR(name, S_IRUGO, show_name, NULL);
static struct attribute *fam15h_power_attrs[] = {
&dev_attr_power1_input.attr,
&dev_attr_power1_crit.attr,
&dev_attr_name.attr,
NULL
};
static const struct attribute_group fam15h_power_attr_group = {
.attrs = fam15h_power_attrs,
};
static bool __devinit fam15h_power_is_internal_node0(struct pci_dev *f4)
{
u32 val;
pci_bus_read_config_dword(f4->bus, PCI_DEVFN(PCI_SLOT(f4->devfn), 3),
REG_NORTHBRIDGE_CAP, &val);
if ((val & BIT(29)) && ((val >> 30) & 3))
return false;
return true;
}
static void __devinit fam15h_power_init_data(struct pci_dev *f4,
struct fam15h_power_data *data)
{
u32 val;
u64 tmp;
pci_read_config_dword(f4, REG_PROCESSOR_TDP, &val);
data->base_tdp = val >> 16;
tmp = val & 0xffff;
pci_bus_read_config_dword(f4->bus, PCI_DEVFN(PCI_SLOT(f4->devfn), 5),
REG_TDP_LIMIT3, &val);
data->tdp_to_watts = ((val & 0x3ff) << 6) | ((val >> 10) & 0x3f);
tmp *= data->tdp_to_watts;
/* result not allowed to be >= 256W */
if ((tmp >> 16) >= 256)
dev_warn(&f4->dev, "Bogus value for ProcessorPwrWatts "
"(processor_pwr_watts>=%u)\n",
(unsigned int) (tmp >> 16));
/* convert to microWatt */
data->processor_pwr_watts = (tmp * 15625) >> 10;
}
static int __devinit fam15h_power_probe(struct pci_dev *pdev,
const struct pci_device_id *id)
{
struct fam15h_power_data *data;
struct device *dev;
int err;
if (!fam15h_power_is_internal_node0(pdev)) {
err = -ENODEV;
goto exit;
}
data = kzalloc(sizeof(struct fam15h_power_data), GFP_KERNEL);
if (!data) {
err = -ENOMEM;
goto exit;
}
fam15h_power_init_data(pdev, data);
dev = &pdev->dev;
dev_set_drvdata(dev, data);
err = sysfs_create_group(&dev->kobj, &fam15h_power_attr_group);
if (err)
goto exit_free_data;
data->hwmon_dev = hwmon_device_register(dev);
if (IS_ERR(data->hwmon_dev)) {
err = PTR_ERR(data->hwmon_dev);
goto exit_remove_group;
}
return 0;
exit_remove_group:
sysfs_remove_group(&dev->kobj, &fam15h_power_attr_group);
exit_free_data:
kfree(data);
exit:
return err;
}
static void __devexit fam15h_power_remove(struct pci_dev *pdev)
{
struct device *dev;
struct fam15h_power_data *data;
dev = &pdev->dev;
data = dev_get_drvdata(dev);
hwmon_device_unregister(data->hwmon_dev);
sysfs_remove_group(&dev->kobj, &fam15h_power_attr_group);
dev_set_drvdata(dev, NULL);
kfree(data);
}
static DEFINE_PCI_DEVICE_TABLE(fam15h_power_id_table) = {
{ PCI_VDEVICE(AMD, PCI_DEVICE_ID_AMD_15H_NB_F4) },
{}
};
MODULE_DEVICE_TABLE(pci, fam15h_power_id_table);
static struct pci_driver fam15h_power_driver = {
.name = "fam15h_power",
.id_table = fam15h_power_id_table,
.probe = fam15h_power_probe,
.remove = __devexit_p(fam15h_power_remove),
};
static int __init fam15h_power_init(void)
{
return pci_register_driver(&fam15h_power_driver);
}
static void __exit fam15h_power_exit(void)
{
pci_unregister_driver(&fam15h_power_driver);
}
module_init(fam15h_power_init)
module_exit(fam15h_power_exit)
