hwmon: Add driver for VIA CPU core temperature
authorHarald Welte <HaraldWelte@viatech.com>
Wed, 16 Dec 2009 20:38:28 +0000 (21:38 +0100)
committerJean Delvare <khali@linux-fr.org>
Wed, 16 Dec 2009 20:38:28 +0000 (21:38 +0100)
This is a driver for the on-die digital temperature sensor of
VIA's recent CPU models.

[JD: Misc clean-ups.]

Signed-off-by: Harald Welte <HaraldWelte@viatech.com>
Cc: Juerg Haefliger <juergh@gmail.com>
Signed-off-by: Jean Delvare <khali@linux-fr.org>
Tested-by: Adam Nielsen <a.nielsen@shikadi.net>
drivers/hwmon/Kconfig
drivers/hwmon/Makefile
drivers/hwmon/via-cputemp.c [new file with mode: 0644]

index 665947fbcdcb808222e5911e5534cee0ea75c6ed..be8eeadb2ee9571b4deab0ebc07b730cb5730d75 100644 (file)
@@ -822,6 +822,14 @@ config SENSORS_TMP421
          This driver can also be built as a module.  If so, the module
          will be called tmp421.
 
+config SENSORS_VIA_CPUTEMP
+       tristate "VIA CPU temperature sensor"
+       depends on X86
+       help
+         If you say yes here you get support for the temperature
+         sensor inside your CPU. Supported are all known variants of
+         the VIA C7 and Nano.
+
 config SENSORS_VIA686A
        tristate "VIA686A"
        depends on PCI
index da84a6a69593b5b9e055865402a8ef44c026bcba..312b7c39d9f4f000371a0b40bc69d100f1847ada 100644 (file)
@@ -88,6 +88,7 @@ obj-$(CONFIG_SENSORS_SMSC47M192)+= smsc47m192.o
 obj-$(CONFIG_SENSORS_THMC50)   += thmc50.o
 obj-$(CONFIG_SENSORS_TMP401)   += tmp401.o
 obj-$(CONFIG_SENSORS_TMP421)   += tmp421.o
+obj-$(CONFIG_SENSORS_VIA_CPUTEMP)+= via-cputemp.o
 obj-$(CONFIG_SENSORS_VIA686A)  += via686a.o
 obj-$(CONFIG_SENSORS_VT1211)   += vt1211.o
 obj-$(CONFIG_SENSORS_VT8231)   += vt8231.o
diff --git a/drivers/hwmon/via-cputemp.c b/drivers/hwmon/via-cputemp.c
new file mode 100644 (file)
index 0000000..7442cf7
--- /dev/null
@@ -0,0 +1,356 @@
+/*
+ * via-cputemp.c - Driver for VIA CPU core temperature monitoring
+ * Copyright (C) 2009 VIA Technologies, Inc.
+ *
+ * based on existing coretemp.c, which is
+ *
+ * Copyright (C) 2007 Rudolf Marek <r.marek@assembler.cz>
+ *
+ * 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; version 2 of the License.
+ *
+ * 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.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
+ * 02110-1301 USA.
+ */
+
+#include <linux/module.h>
+#include <linux/delay.h>
+#include <linux/init.h>
+#include <linux/slab.h>
+#include <linux/jiffies.h>
+#include <linux/hwmon.h>
+#include <linux/sysfs.h>
+#include <linux/hwmon-sysfs.h>
+#include <linux/err.h>
+#include <linux/mutex.h>
+#include <linux/list.h>
+#include <linux/platform_device.h>
+#include <linux/cpu.h>
+#include <asm/msr.h>
+#include <asm/processor.h>
+
+#define DRVNAME        "via_cputemp"
+
+enum { SHOW_TEMP, SHOW_LABEL, SHOW_NAME } SHOW;
+
+/*
+ * Functions declaration
+ */
+
+struct via_cputemp_data {
+       struct device *hwmon_dev;
+       const char *name;
+       u32 id;
+       u32 msr;
+};
+
+/*
+ * Sysfs stuff
+ */
+
+static ssize_t show_name(struct device *dev, struct device_attribute
+                         *devattr, char *buf)
+{
+       int ret;
+       struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
+       struct via_cputemp_data *data = dev_get_drvdata(dev);
+
+       if (attr->index == SHOW_NAME)
+               ret = sprintf(buf, "%s\n", data->name);
+       else    /* show label */
+               ret = sprintf(buf, "Core %d\n", data->id);
+       return ret;
+}
+
+static ssize_t show_temp(struct device *dev,
+                        struct device_attribute *devattr, char *buf)
+{
+       struct via_cputemp_data *data = dev_get_drvdata(dev);
+       u32 eax, edx;
+       int err;
+
+       err = rdmsr_safe_on_cpu(data->id, data->msr, &eax, &edx);
+       if (err)
+               return -EAGAIN;
+
+       return sprintf(buf, "%lu\n", ((unsigned long)eax & 0xffffff) * 1000);
+}
+
+static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, show_temp, NULL,
+                         SHOW_TEMP);
+static SENSOR_DEVICE_ATTR(temp1_label, S_IRUGO, show_name, NULL, SHOW_LABEL);
+static SENSOR_DEVICE_ATTR(name, S_IRUGO, show_name, NULL, SHOW_NAME);
+
+static struct attribute *via_cputemp_attributes[] = {
+       &sensor_dev_attr_name.dev_attr.attr,
+       &sensor_dev_attr_temp1_label.dev_attr.attr,
+       &sensor_dev_attr_temp1_input.dev_attr.attr,
+       NULL
+};
+
+static const struct attribute_group via_cputemp_group = {
+       .attrs = via_cputemp_attributes,
+};
+
+static int __devinit via_cputemp_probe(struct platform_device *pdev)
+{
+       struct via_cputemp_data *data;
+       struct cpuinfo_x86 *c = &cpu_data(pdev->id);
+       int err;
+       u32 eax, edx;
+
+       data = kzalloc(sizeof(struct via_cputemp_data), GFP_KERNEL);
+       if (!data) {
+               err = -ENOMEM;
+               dev_err(&pdev->dev, "Out of memory\n");
+               goto exit;
+       }
+
+       data->id = pdev->id;
+       data->name = "via_cputemp";
+
+       switch (c->x86_model) {
+       case 0xA:
+               /* C7 A */
+       case 0xD:
+               /* C7 D */
+               data->msr = 0x1169;
+               break;
+       case 0xF:
+               /* Nano */
+               data->msr = 0x1423;
+               break;
+       default:
+               err = -ENODEV;
+               goto exit_free;
+       }
+
+       /* test if we can access the TEMPERATURE MSR */
+       err = rdmsr_safe_on_cpu(data->id, data->msr, &eax, &edx);
+       if (err) {
+               dev_err(&pdev->dev,
+                       "Unable to access TEMPERATURE MSR, giving up\n");
+               goto exit_free;
+       }
+
+       platform_set_drvdata(pdev, data);
+
+       err = sysfs_create_group(&pdev->dev.kobj, &via_cputemp_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);
+               dev_err(&pdev->dev, "Class registration failed (%d)\n",
+                       err);
+               goto exit_remove;
+       }
+
+       return 0;
+
+exit_remove:
+       sysfs_remove_group(&pdev->dev.kobj, &via_cputemp_group);
+exit_free:
+       platform_set_drvdata(pdev, NULL);
+       kfree(data);
+exit:
+       return err;
+}
+
+static int __devexit via_cputemp_remove(struct platform_device *pdev)
+{
+       struct via_cputemp_data *data = platform_get_drvdata(pdev);
+
+       hwmon_device_unregister(data->hwmon_dev);
+       sysfs_remove_group(&pdev->dev.kobj, &via_cputemp_group);
+       platform_set_drvdata(pdev, NULL);
+       kfree(data);
+       return 0;
+}
+
+static struct platform_driver via_cputemp_driver = {
+       .driver = {
+               .owner = THIS_MODULE,
+               .name = DRVNAME,
+       },
+       .probe = via_cputemp_probe,
+       .remove = __devexit_p(via_cputemp_remove),
+};
+
+struct pdev_entry {
+       struct list_head list;
+       struct platform_device *pdev;
+       unsigned int cpu;
+};
+
+static LIST_HEAD(pdev_list);
+static DEFINE_MUTEX(pdev_list_mutex);
+
+static int __cpuinit via_cputemp_device_add(unsigned int cpu)
+{
+       int err;
+       struct platform_device *pdev;
+       struct pdev_entry *pdev_entry;
+
+       pdev = platform_device_alloc(DRVNAME, cpu);
+       if (!pdev) {
+               err = -ENOMEM;
+               printk(KERN_ERR DRVNAME ": Device allocation failed\n");
+               goto exit;
+       }
+
+       pdev_entry = kzalloc(sizeof(struct pdev_entry), GFP_KERNEL);
+       if (!pdev_entry) {
+               err = -ENOMEM;
+               goto exit_device_put;
+       }
+
+       err = platform_device_add(pdev);
+       if (err) {
+               printk(KERN_ERR DRVNAME ": Device addition failed (%d)\n",
+                      err);
+               goto exit_device_free;
+       }
+
+       pdev_entry->pdev = pdev;
+       pdev_entry->cpu = cpu;
+       mutex_lock(&pdev_list_mutex);
+       list_add_tail(&pdev_entry->list, &pdev_list);
+       mutex_unlock(&pdev_list_mutex);
+
+       return 0;
+
+exit_device_free:
+       kfree(pdev_entry);
+exit_device_put:
+       platform_device_put(pdev);
+exit:
+       return err;
+}
+
+#ifdef CONFIG_HOTPLUG_CPU
+static void via_cputemp_device_remove(unsigned int cpu)
+{
+       struct pdev_entry *p, *n;
+       mutex_lock(&pdev_list_mutex);
+       list_for_each_entry_safe(p, n, &pdev_list, list) {
+               if (p->cpu == cpu) {
+                       platform_device_unregister(p->pdev);
+                       list_del(&p->list);
+                       kfree(p);
+               }
+       }
+       mutex_unlock(&pdev_list_mutex);
+}
+
+static int __cpuinit via_cputemp_cpu_callback(struct notifier_block *nfb,
+                                unsigned long action, void *hcpu)
+{
+       unsigned int cpu = (unsigned long) hcpu;
+
+       switch (action) {
+       case CPU_ONLINE:
+       case CPU_DOWN_FAILED:
+               via_cputemp_device_add(cpu);
+               break;
+       case CPU_DOWN_PREPARE:
+               via_cputemp_device_remove(cpu);
+               break;
+       }
+       return NOTIFY_OK;
+}
+
+static struct notifier_block via_cputemp_cpu_notifier __refdata = {
+       .notifier_call = via_cputemp_cpu_callback,
+};
+#endif                         /* !CONFIG_HOTPLUG_CPU */
+
+static int __init via_cputemp_init(void)
+{
+       int i, err;
+       struct pdev_entry *p, *n;
+
+       if (cpu_data(0).x86_vendor != X86_VENDOR_CENTAUR) {
+               printk(KERN_DEBUG DRVNAME ": Not a VIA CPU\n");
+               err = -ENODEV;
+               goto exit;
+       }
+
+       err = platform_driver_register(&via_cputemp_driver);
+       if (err)
+               goto exit;
+
+       for_each_online_cpu(i) {
+               struct cpuinfo_x86 *c = &cpu_data(i);
+
+               if (c->x86 != 6)
+                       continue;
+
+               if (c->x86_model < 0x0a)
+                       continue;
+
+               if (c->x86_model > 0x0f) {
+                       printk(KERN_WARNING DRVNAME ": Unknown CPU "
+                               "model 0x%x\n", c->x86_model);
+                       continue;
+               }
+
+               err = via_cputemp_device_add(i);
+               if (err)
+                       goto exit_devices_unreg;
+       }
+       if (list_empty(&pdev_list)) {
+               err = -ENODEV;
+               goto exit_driver_unreg;
+       }
+
+#ifdef CONFIG_HOTPLUG_CPU
+       register_hotcpu_notifier(&via_cputemp_cpu_notifier);
+#endif
+       return 0;
+
+exit_devices_unreg:
+       mutex_lock(&pdev_list_mutex);
+       list_for_each_entry_safe(p, n, &pdev_list, list) {
+               platform_device_unregister(p->pdev);
+               list_del(&p->list);
+               kfree(p);
+       }
+       mutex_unlock(&pdev_list_mutex);
+exit_driver_unreg:
+       platform_driver_unregister(&via_cputemp_driver);
+exit:
+       return err;
+}
+
+static void __exit via_cputemp_exit(void)
+{
+       struct pdev_entry *p, *n;
+#ifdef CONFIG_HOTPLUG_CPU
+       unregister_hotcpu_notifier(&via_cputemp_cpu_notifier);
+#endif
+       mutex_lock(&pdev_list_mutex);
+       list_for_each_entry_safe(p, n, &pdev_list, list) {
+               platform_device_unregister(p->pdev);
+               list_del(&p->list);
+               kfree(p);
+       }
+       mutex_unlock(&pdev_list_mutex);
+       platform_driver_unregister(&via_cputemp_driver);
+}
+
+MODULE_AUTHOR("Harald Welte <HaraldWelte@viatech.com>");
+MODULE_DESCRIPTION("VIA CPU temperature monitor");
+MODULE_LICENSE("GPL");
+
+module_init(via_cputemp_init)
+module_exit(via_cputemp_exit)