[PATCH v2] hwmon: Add driver for AMD family 15h processor power information

[Andreas Herrmann <herrmann.der.user@googlemail.com>]

From: Andreas Herrmann <andreas.herrmann3@amd.com>

This CPU family provides NB register values to gather following
TDP information

* ProcessorPwrWatts: Specifies in Watts the maximum amount of power
  the processor can support.
* CurrPwrWatts: Specifies in Watts the current amount of power being
  consumed by the processor.

This driver provides

* power1_cap (ProcessorPwrWatts)
* power1_input (CurrPwrWatts)

Changes from v1::
 - removed deprecated code line,
 - fixed comment,
 - report power only once per socket (Power information is provided
   for the entire package. On multi-node processors it should only be
   reported on internal node 0.)

Signed-off-by: Andreas Herrmann <andreas.herrmann3@amd.com>
---
 drivers/hwmon/Kconfig      |   10 ++
 drivers/hwmon/Makefile     |    1 +
 drivers/hwmon/f15h_power.c |  216 ++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 227 insertions(+), 0 deletions(-)
 create mode 100644 drivers/hwmon/f15h_power.c

diff --git a/drivers/hwmon/Kconfig b/drivers/hwmon/Kconfig
index 8e84b31..0268623 100644
--- a/drivers/hwmon/Kconfig
+++ b/drivers/hwmon/Kconfig
@@ -249,6 +249,16 @@ config SENSORS_K10TEMP
 	  This driver can also be built as a module.  If so, the module
 	  will be called k10temp.
 
+config SENSORS_F15H_POWER
+	tristate "AMD Family 15h processor power"
+	depends on X86 && PCI
+	help
+	  If you say yes here you get support for processor power
+	  information of your AMD family 15h CPU.
+
+	  This driver can also be built as a module.  If so, the module
+	  will be called f15hpower.
+
 config SENSORS_ASB100
 	tristate "Asus ASB100 Bach"
 	depends on X86 && I2C && EXPERIMENTAL
diff --git a/drivers/hwmon/Makefile b/drivers/hwmon/Makefile
index dde02d9..e554b88 100644
--- a/drivers/hwmon/Makefile
+++ b/drivers/hwmon/Makefile
@@ -62,6 +62,7 @@ obj-$(CONFIG_SENSORS_JC42)	+= jc42.o
 obj-$(CONFIG_SENSORS_JZ4740)	+= jz4740-hwmon.o
 obj-$(CONFIG_SENSORS_K8TEMP)	+= k8temp.o
 obj-$(CONFIG_SENSORS_K10TEMP)	+= k10temp.o
+obj-$(CONFIG_SENSORS_F15H_POWER) += f15h_power.o
 obj-$(CONFIG_SENSORS_LIS3LV02D) += lis3lv02d.o hp_accel.o
 obj-$(CONFIG_SENSORS_LIS3_SPI)	+= lis3lv02d.o lis3lv02d_spi.o
 obj-$(CONFIG_SENSORS_LIS3_I2C)	+= lis3lv02d.o lis3lv02d_i2c.o
diff --git a/drivers/hwmon/f15h_power.c b/drivers/hwmon/f15h_power.c
new file mode 100644
index 0000000..40e3cbd
--- /dev/null
+++ b/drivers/hwmon/f15h_power.c
@@ -0,0 +1,216 @@
+/*
+ * f15h_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
+
+static ssize_t show_power(struct device *dev,
+			  struct device_attribute *attr, char *buf)
+{
+	u32 val, btdp, tdpl, tdp2w, arange;
+	s32 acap;
+	u64 ctdp;
+	struct pci_dev *f4 = to_pci_dev(dev);
+	struct pci_dev *f5;
+
+	pci_read_config_dword(f4, REG_PROCESSOR_TDP, &val);
+	btdp = (val >> 16) & 0xffff;
+
+	f5 = pci_get_slot(f4->bus, PCI_DEVFN(PCI_SLOT(f4->devfn), 5));
+	if (!f5) {
+		dev_err(dev, "no function 5 available on this slot\n");
+		return 0;
+	}
+
+	pci_read_config_dword(f5, REG_TDP_RUNNING_AVERAGE, &val);
+	acap = (val >> 4) & 0x3fffff;
+	acap = sign_extend32(acap, 22);
+	arange = val & 0xf;
+
+	pci_read_config_dword(f5, REG_TDP_LIMIT3, &val);
+	pci_dev_put(f5);
+
+	tdpl = (val >> 16) & 0x1fff;
+	tdp2w = ((val & 0x3ff) << 6) | ((val >> 10) & 0x3f);
+	ctdp = tdpl - (s32)(acap >> (arange + 1)) + btdp;
+	ctdp *= tdp2w;
+
+	/*
+	 * 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)
+	 */
+	ctdp = (ctdp * 15625) >> 10;
+	return sprintf(buf, "%d\n", (u32) ctdp);
+}
+static DEVICE_ATTR(power1_input, S_IRUGO, show_power, NULL);
+
+static ssize_t show_power_cap(struct device *dev,
+			     struct device_attribute *attr, char *buf)
+{
+	u32 val, tdp2w;
+	u64 ptdp;
+	struct pci_dev *f4 = to_pci_dev(dev);
+	struct pci_dev *f5;
+
+	pci_read_config_dword(f4, REG_PROCESSOR_TDP, &val);
+	ptdp = val & 0xffff;
+
+	f5 = pci_get_slot(f4->bus, PCI_DEVFN(PCI_SLOT(f4->devfn), 5));
+	if (!f5) {
+		dev_err(dev, "no function 5 available on this slot\n");
+		return 0;
+	}
+
+	pci_read_config_dword(f5, REG_TDP_LIMIT3, &val);
+	pci_dev_put(f5);
+
+	tdp2w = ((val & 0x3ff) << 6) | ((val >> 10) & 0x3f);
+	ptdp *= tdp2w;
+
+	/* result not allowed to be >= 256W */
+	WARN_ON(ptdp>>16 >= 256);
+
+	/* convert to microWatt */
+	ptdp = (ptdp * 15625) >> 10;
+	return sprintf(buf, "%d\n", (u32) ptdp);
+}
+static DEVICE_ATTR(power1_cap, S_IRUGO, show_power_cap, NULL);
+
+static ssize_t show_name(struct device *dev,
+			 struct device_attribute *attr, char *buf)
+{
+	return sprintf(buf, "f15h_power\n");
+}
+static DEVICE_ATTR(name, S_IRUGO, show_name, NULL);
+
+static int __devinit f15h_power_is_internal_node0(struct pci_dev *f4)
+{
+	u32 val;
+	struct pci_dev *f3;
+
+	f3 = pci_get_slot(f4->bus, PCI_DEVFN(PCI_SLOT(f4->devfn), 3));
+	if (!f3) {
+		dev_err(&f4->dev, "no function 3 available on this slot\n");
+		return 0;
+	}
+
+	pci_read_config_dword(f3, REG_NORTHBRIDGE_CAP, &val);
+	pci_dev_put(f3);
+
+	if ((val & BIT(29)) && ((val >> 30) & 3))
+		return 0;
+
+	return 1;
+}
+
+static int __devinit f15h_power_probe(struct pci_dev *pdev,
+				      const struct pci_device_id *id)
+{
+	struct device *hwmon_dev;
+	int err = -ENODEV;
+
+	if (!f15h_power_is_internal_node0(pdev))
+		goto exit;
+
+	err = device_create_file(&pdev->dev, &dev_attr_power1_input);
+	if (err)
+		goto exit;
+	err = device_create_file(&pdev->dev, &dev_attr_power1_cap);
+	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;
+	}
+	dev_set_drvdata(&pdev->dev, hwmon_dev);
+
+	return 0;
+
+exit_remove:
+	device_remove_file(&pdev->dev, &dev_attr_name);
+	device_remove_file(&pdev->dev, &dev_attr_power1_input);
+	device_remove_file(&pdev->dev, &dev_attr_power1_cap);
+exit:
+	return err;
+}
+
+static void __devexit f15h_power_remove(struct pci_dev *pdev)
+{
+	hwmon_device_unregister(dev_get_drvdata(&pdev->dev));
+	device_remove_file(&pdev->dev, &dev_attr_name);
+	device_remove_file(&pdev->dev, &dev_attr_power1_input);
+	device_remove_file(&pdev->dev, &dev_attr_power1_cap);
+	dev_set_drvdata(&pdev->dev, NULL);
+}
+
+static const struct pci_device_id f15h_power_id_table[] = {
+	{ PCI_VDEVICE(AMD, PCI_DEVICE_ID_AMD_15H_NB_LINK) },
+	{}
+};
+MODULE_DEVICE_TABLE(pci, f15h_power_id_table);
+
+static struct pci_driver f15h_power_driver = {
+	.name = "f15h_power",
+	.id_table = f15h_power_id_table,
+	.probe = f15h_power_probe,
+	.remove = __devexit_p(f15h_power_remove),
+};
+
+static int __init f15h_power_init(void)
+{
+	return pci_register_driver(&f15h_power_driver);
+}
+
+static void __exit f15h_power_exit(void)
+{
+	pci_unregister_driver(&f15h_power_driver);
+}
+
+module_init(f15h_power_init)
+module_exit(f15h_power_exit)
-- 
1.7.3.1