/*

   * k10temp.c - AMD Family 10h/11h/12h/14h/15h processor hardware monitoring

   *
   * Copyright (c) 2009 Clemens Ladisch <clemens@ladisch.de>
   *
   *
   * 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 <asm/processor.h>

  MODULE_DESCRIPTION("AMD Family 10h+ CPU core temperature monitor");

  MODULE_AUTHOR("Clemens Ladisch <clemens@ladisch.de>");
  MODULE_LICENSE("GPL");
  
  static bool force;
  module_param(force, bool, 0444);
  MODULE_PARM_DESC(force, "force loading on processors with erratum 319");

  /* CPUID function 0x80000001, ebx */
  #define CPUID_PKGTYPE_MASK	0xf0000000
  #define CPUID_PKGTYPE_F		0x00000000
  #define CPUID_PKGTYPE_AM2R2_AM3	0x10000000
  
  /* DRAM controller (PCI function 2) */
  #define REG_DCT0_CONFIG_HIGH		0x094
  #define  DDR3_MODE			0x00000100
  
  /* miscellaneous (PCI function 3) */

  #define REG_HARDWARE_THERMAL_CONTROL	0x64
  #define  HTC_ENABLE			0x00000001
  
  #define REG_REPORTED_TEMPERATURE	0xa4
  
  #define REG_NORTHBRIDGE_CAPABILITIES	0xe8
  #define  NB_CAP_HTC			0x00000400
  
  static ssize_t show_temp(struct device *dev,
  			 struct device_attribute *attr, char *buf)
  {
  	u32 regval;
  
  	pci_read_config_dword(to_pci_dev(dev),
  			      REG_REPORTED_TEMPERATURE, &regval);
  	return sprintf(buf, "%u
  ", (regval >> 21) * 125);
  }
  
  static ssize_t show_temp_max(struct device *dev,
  			     struct device_attribute *attr, char *buf)
  {
  	return sprintf(buf, "%d
  ", 70 * 1000);
  }
  
  static ssize_t show_temp_crit(struct device *dev,
  			      struct device_attribute *devattr, char *buf)
  {
  	struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
  	int show_hyst = attr->index;
  	u32 regval;
  	int value;
  
  	pci_read_config_dword(to_pci_dev(dev),
  			      REG_HARDWARE_THERMAL_CONTROL, &regval);
  	value = ((regval >> 16) & 0x7f) * 500 + 52000;
  	if (show_hyst)
  		value -= ((regval >> 24) & 0xf) * 500;
  	return sprintf(buf, "%d
  ", value);
  }
  
  static ssize_t show_name(struct device *dev,
  			 struct device_attribute *attr, char *buf)
  {
  	return sprintf(buf, "k10temp
  ");
  }
  
  static DEVICE_ATTR(temp1_input, S_IRUGO, show_temp, NULL);
  static DEVICE_ATTR(temp1_max, S_IRUGO, show_temp_max, NULL);
  static SENSOR_DEVICE_ATTR(temp1_crit, S_IRUGO, show_temp_crit, NULL, 0);
  static SENSOR_DEVICE_ATTR(temp1_crit_hyst, S_IRUGO, show_temp_crit, NULL, 1);
  static DEVICE_ATTR(name, S_IRUGO, show_name, NULL);

  static bool __devinit has_erratum_319(struct pci_dev *pdev)

  {

  	u32 pkg_type, reg_dram_cfg;
  
  	if (boot_cpu_data.x86 != 0x10)
  		return false;

  	/*

  	 * Erratum 319: The thermal sensor of Socket F/AM2+ processors
  	 *              may be unreliable.

  	 */

  	pkg_type = cpuid_ebx(0x80000001) & CPUID_PKGTYPE_MASK;
  	if (pkg_type == CPUID_PKGTYPE_F)
  		return true;
  	if (pkg_type != CPUID_PKGTYPE_AM2R2_AM3)
  		return false;

  	/* DDR3 memory implies socket AM3, which is good */

  	pci_bus_read_config_dword(pdev->bus,
  				  PCI_DEVFN(PCI_SLOT(pdev->devfn), 2),
  				  REG_DCT0_CONFIG_HIGH, &reg_dram_cfg);

  	if (reg_dram_cfg & DDR3_MODE)
  		return false;
  
  	/*
  	 * Unfortunately it is possible to run a socket AM3 CPU with DDR2
  	 * memory. We blacklist all the cores which do exist in socket AM2+
  	 * format. It still isn't perfect, as RB-C2 cores exist in both AM2+
  	 * and AM3 formats, but that's the best we can do.
  	 */
  	return boot_cpu_data.x86_model < 4 ||
  	       (boot_cpu_data.x86_model == 4 && boot_cpu_data.x86_mask <= 2);

  }
  
  static int __devinit k10temp_probe(struct pci_dev *pdev,
  				   const struct pci_device_id *id)
  {
  	struct device *hwmon_dev;
  	u32 reg_caps, reg_htc;

  	int unreliable = has_erratum_319(pdev);

  	int err;

  	if (unreliable && !force) {

  		dev_err(&pdev->dev,
  			"unreliable CPU thermal sensor; monitoring disabled
  ");
  		err = -ENODEV;
  		goto exit;
  	}
  
  	err = device_create_file(&pdev->dev, &dev_attr_temp1_input);
  	if (err)
  		goto exit;
  	err = device_create_file(&pdev->dev, &dev_attr_temp1_max);
  	if (err)
  		goto exit_remove;
  
  	pci_read_config_dword(pdev, REG_NORTHBRIDGE_CAPABILITIES, &reg_caps);
  	pci_read_config_dword(pdev, REG_HARDWARE_THERMAL_CONTROL, &reg_htc);
  	if ((reg_caps & NB_CAP_HTC) && (reg_htc & HTC_ENABLE)) {
  		err = device_create_file(&pdev->dev,
  				&sensor_dev_attr_temp1_crit.dev_attr);
  		if (err)
  			goto exit_remove;
  		err = device_create_file(&pdev->dev,
  				&sensor_dev_attr_temp1_crit_hyst.dev_attr);
  		if (err)
  			goto exit_remove;
  	}
  
  	err = device_create_file(&pdev->dev, &dev_attr_name);
  	if (err)
  		goto exit_remove;
  
  	hwmon_dev = hwmon_device_register(&pdev->dev);
  	if (IS_ERR(hwmon_dev)) {
  		err = PTR_ERR(hwmon_dev);
  		goto exit_remove;
  	}

  	pci_set_drvdata(pdev, hwmon_dev);

  	if (unreliable && force)

  		dev_warn(&pdev->dev,
  			 "unreliable CPU thermal sensor; check erratum 319
  ");
  	return 0;
  
  exit_remove:
  	device_remove_file(&pdev->dev, &dev_attr_name);
  	device_remove_file(&pdev->dev, &dev_attr_temp1_input);
  	device_remove_file(&pdev->dev, &dev_attr_temp1_max);
  	device_remove_file(&pdev->dev,
  			   &sensor_dev_attr_temp1_crit.dev_attr);
  	device_remove_file(&pdev->dev,
  			   &sensor_dev_attr_temp1_crit_hyst.dev_attr);
  exit:
  	return err;
  }
  
  static void __devexit k10temp_remove(struct pci_dev *pdev)
  {

  	hwmon_device_unregister(pci_get_drvdata(pdev));

  	device_remove_file(&pdev->dev, &dev_attr_name);
  	device_remove_file(&pdev->dev, &dev_attr_temp1_input);
  	device_remove_file(&pdev->dev, &dev_attr_temp1_max);
  	device_remove_file(&pdev->dev,
  			   &sensor_dev_attr_temp1_crit.dev_attr);
  	device_remove_file(&pdev->dev,
  			   &sensor_dev_attr_temp1_crit_hyst.dev_attr);

  	pci_set_drvdata(pdev, NULL);

  }

  static const struct pci_device_id k10temp_id_table[] = {

  	{ PCI_VDEVICE(AMD, PCI_DEVICE_ID_AMD_10H_NB_MISC) },
  	{ PCI_VDEVICE(AMD, PCI_DEVICE_ID_AMD_11H_NB_MISC) },

  	{ PCI_VDEVICE(AMD, PCI_DEVICE_ID_AMD_CNB17H_F3) },

  	{ PCI_VDEVICE(AMD, PCI_DEVICE_ID_AMD_15H_NB_F3) },

  	{}
  };
  MODULE_DEVICE_TABLE(pci, k10temp_id_table);
  
  static struct pci_driver k10temp_driver = {
  	.name = "k10temp",
  	.id_table = k10temp_id_table,
  	.probe = k10temp_probe,
  	.remove = __devexit_p(k10temp_remove),
  };
  
  static int __init k10temp_init(void)
  {
  	return pci_register_driver(&k10temp_driver);
  }
  
  static void __exit k10temp_exit(void)
  {
  	pci_unregister_driver(&k10temp_driver);
  }
  
  module_init(k10temp_init)
  module_exit(k10temp_exit)