hwmon: (i5500_temp) New driver for the Intel 5500/5520/X58 chipsets

The Intel 5500, 5520 and X58 chipsets embed a digital thermal sensor.
This new driver supports it.

Note that on many boards the sensor seems to be disabled and reports
the minimum value (36.5 degrees Celsius) all the time.

Signed-off-by: Jean Delvare <jdelvare@suse.de>
Tested-by: Romain Dolbeau <romain@dolbeau.org>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>

drivers/hwmon/Kconfig

@@ -574,6 +574,16 @@ config SENSORS_IIO_HWMON
 	  for those channels specified in the map.  This map can be provided
 	  either via platform data or the device tree bindings.
 
+config SENSORS_I5500
+	tristate "Intel 5500/5520/X58 temperature sensor"
+	depends on X86 && PCI
+	help
+	  If you say yes here you get support for the temperature
+	  sensor inside the Intel 5500, 5520 and X58 chipsets.
+
+	  This driver can also be built as a module. If so, the module
+	  will be called i5500_temp.
+
 config SENSORS_CORETEMP
 	tristate "Intel Core/Core2/Atom temperature sensor"
 	depends on X86

drivers/hwmon/Makefile

@@ -68,6 +68,7 @@ obj-$(CONFIG_SENSORS_GPIO_FAN)	+= gpio-fan.o
 obj-$(CONFIG_SENSORS_HIH6130)	+= hih6130.o
 obj-$(CONFIG_SENSORS_HTU21)	+= htu21.o
 obj-$(CONFIG_SENSORS_ULTRA45)	+= ultra45_env.o
+obj-$(CONFIG_SENSORS_I5500)	+= i5500_temp.o
 obj-$(CONFIG_SENSORS_I5K_AMB)	+= i5k_amb.o
 obj-$(CONFIG_SENSORS_IBMAEM)	+= ibmaem.o
 obj-$(CONFIG_SENSORS_IBMPEX)	+= ibmpex.o

drivers/hwmon/i5500_temp.c

@@ -0,0 +1,201 @@
+/*
+ * i5500_temp - Driver for Intel 5500/5520/X58 chipset thermal sensor
+ *
+ * Copyright (C) 2012, 2014 Jean Delvare <jdelvare@suse.de>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program 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.
+ */
+
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/slab.h>
+#include <linux/jiffies.h>
+#include <linux/pci.h>
+#include <linux/hwmon.h>
+#include <linux/hwmon-sysfs.h>
+#include <linux/err.h>
+#include <linux/mutex.h>
+
+/* Register definitions from datasheet */
+#define REG_TSTHRCATA	0xE2
+#define REG_TSCTRL	0xE8
+#define REG_TSTHRRPEX	0xEB
+#define REG_TSTHRLO	0xEC
+#define REG_TSTHRHI	0xEE
+#define REG_CTHINT	0xF0
+#define REG_TSFSC	0xF3
+#define REG_CTSTS	0xF4
+#define REG_TSTHRRQPI	0xF5
+#define REG_CTCTRL	0xF7
+#define REG_TSTIMER	0xF8
+
+struct i5500_temp_data {
+	struct device *hwmon_dev;
+	const char *name;
+};
+
+/*
+ * Sysfs stuff
+ */
+
+/* Sensor resolution : 0.5 degree C */
+static ssize_t show_temp(struct device *dev,
+			 struct device_attribute *devattr, char *buf)
+{
+	struct pci_dev *pdev = to_pci_dev(dev);
+	long temp;
+	u16 tsthrhi;
+	s8 tsfsc;
+
+	pci_read_config_word(pdev, REG_TSTHRHI, &tsthrhi);
+	pci_read_config_byte(pdev, REG_TSFSC, &tsfsc);
+	temp = ((long)tsthrhi - tsfsc) * 500;
+
+	return sprintf(buf, "%ld\n", temp);
+}
+
+static ssize_t show_thresh(struct device *dev,
+			   struct device_attribute *devattr, char *buf)
+{
+	struct pci_dev *pdev = to_pci_dev(dev);
+	int reg = to_sensor_dev_attr(devattr)->index;
+	long temp;
+	u16 tsthr;
+
+	pci_read_config_word(pdev, reg, &tsthr);
+	temp = tsthr * 500;
+
+	return sprintf(buf, "%ld\n", temp);
+}
+
+static ssize_t show_alarm(struct device *dev,
+			  struct device_attribute *devattr, char *buf)
+{
+	struct pci_dev *pdev = to_pci_dev(dev);
+	int nr = to_sensor_dev_attr(devattr)->index;
+	u8 ctsts;
+
+	pci_read_config_byte(pdev, REG_CTSTS, &ctsts);
+	return sprintf(buf, "%u\n", (unsigned int)ctsts & (1 << nr));
+}
+
+static ssize_t show_name(struct device *dev, struct device_attribute
+			 *devattr, char *buf)
+{
+	struct i5500_temp_data *data = dev_get_drvdata(dev);
+
+	return sprintf(buf, "%s\n", data->name);
+}
+
+static DEVICE_ATTR(temp1_input, S_IRUGO, show_temp, NULL);
+static SENSOR_DEVICE_ATTR(temp1_crit, S_IRUGO, show_thresh, NULL, 0xE2);
+static SENSOR_DEVICE_ATTR(temp1_max_hyst, S_IRUGO, show_thresh, NULL, 0xEC);
+static SENSOR_DEVICE_ATTR(temp1_max, S_IRUGO, show_thresh, NULL, 0xEE);
+static SENSOR_DEVICE_ATTR(temp1_crit_alarm, S_IRUGO, show_alarm, NULL, 0);
+static SENSOR_DEVICE_ATTR(temp1_max_alarm, S_IRUGO, show_alarm, NULL, 1);
+static DEVICE_ATTR(name, S_IRUGO, show_name, NULL);
+
+static struct attribute *i5500_temp_attributes[] = {
+	&dev_attr_temp1_input.attr,
+	&sensor_dev_attr_temp1_crit.dev_attr.attr,
+	&sensor_dev_attr_temp1_max_hyst.dev_attr.attr,
+	&sensor_dev_attr_temp1_max.dev_attr.attr,
+	&sensor_dev_attr_temp1_crit_alarm.dev_attr.attr,
+	&sensor_dev_attr_temp1_max_alarm.dev_attr.attr,
+	&dev_attr_name.attr,
+	NULL
+};
+
+static const struct attribute_group i5500_temp_group = {
+	.attrs = i5500_temp_attributes,
+};
+
+static const struct pci_device_id i5500_temp_ids[] = {
+	{ PCI_DEVICE(PCI_VENDOR_ID_INTEL, 0x3438) },
+	{ 0 },
+};
+
+MODULE_DEVICE_TABLE(pci, i5500_temp_ids);
+
+static int i5500_temp_probe(struct pci_dev *pdev,
+			    const struct pci_device_id *id)
+{
+	int err;
+	struct i5500_temp_data *data;
+
+	data = kzalloc(sizeof(struct i5500_temp_data), GFP_KERNEL);
+	if (!data) {
+		err = -ENOMEM;
+		goto exit;
+	}
+
+	data->name = "intel5500";
+	dev_set_drvdata(&pdev->dev, data);
+
+	err = pci_enable_device(pdev);
+	if (err) {
+		dev_err(&pdev->dev, "Failed to enable device\n");
+		goto exit_free;
+	}
+
+	/* Register sysfs hooks */
+	err = sysfs_create_group(&pdev->dev.kobj, &i5500_temp_group);
+	if (err)
+		goto exit_free;
+
+	data->hwmon_dev = hwmon_device_register(&pdev->dev);
+	if (IS_ERR(data->hwmon_dev)) {
+		err = PTR_ERR(data->hwmon_dev);
+		goto exit_remove;
+	}
+
+	return 0;
+
+ exit_remove:
+	sysfs_remove_group(&pdev->dev.kobj, &i5500_temp_group);
+ exit_free:
+	kfree(data);
+ exit:
+	return err;
+}
+
+static void i5500_temp_remove(struct pci_dev *pdev)
+{
+	struct i5500_temp_data *data = dev_get_drvdata(&pdev->dev);
+
+	hwmon_device_unregister(data->hwmon_dev);
+	sysfs_remove_group(&pdev->dev.kobj, &i5500_temp_group);
+	kfree(data);
+}
+
+static struct pci_driver i5500_temp_driver = {
+	.name = "i5500_temp",
+	.id_table = i5500_temp_ids,
+	.probe = i5500_temp_probe,
+	.remove = i5500_temp_remove,
+};
+
+static int __init i5500_temp_init(void)
+{
+	return pci_register_driver(&i5500_temp_driver);
+}
+
+static void __exit i5500_temp_exit(void)
+{
+	pci_unregister_driver(&i5500_temp_driver);
+}
+
+MODULE_AUTHOR("Jean Delvare <jdelvare@suse.de>");
+MODULE_DESCRIPTION("Intel 5500/5520/X58 chipset thermal sensor driver");
+MODULE_LICENSE("GPL");
+
+module_init(i5500_temp_init)
+module_exit(i5500_temp_exit)