Linux 2.6.34-rc3

[pohmelfs.git] / drivers / hwmon / coretemp.c

/*
 * coretemp.c - Linux kernel module for hardware monitoring
 *
 * Copyright (C) 2007 Rudolf Marek <r.marek@assembler.cz>
 *
 * Inspired from many hwmon drivers
 *
 * 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 <linux/pci.h>
#include <asm/msr.h>
#include <asm/processor.h>

#define DRVNAME "coretemp"

typedef enum { SHOW_TEMP, SHOW_TJMAX, SHOW_TTARGET, SHOW_LABEL,
                SHOW_NAME } SHOW;

/*
 * Functions declaration
 */

static struct coretemp_data *coretemp_update_device(struct device *dev);

struct coretemp_data {
        struct device *hwmon_dev;
        struct mutex update_lock;
        const char *name;
        u32 id;
        char valid;             /* zero until following fields are valid */
        unsigned long last_updated;     /* in jiffies */
        int temp;
        int tjmax;
        int ttarget;
        u8 alarm;
};

/*
 * 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 coretemp_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_alarm(struct device *dev, struct device_attribute
                          *devattr, char *buf)
{
        struct coretemp_data *data = coretemp_update_device(dev);
        /* read the Out-of-spec log, never clear */
        return sprintf(buf, "%d\n", data->alarm);
}

static ssize_t show_temp(struct device *dev,
                         struct device_attribute *devattr, char *buf)
{
        struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
        struct coretemp_data *data = coretemp_update_device(dev);
        int err;

        if (attr->index == SHOW_TEMP)
                err = data->valid ? sprintf(buf, "%d\n", data->temp) : -EAGAIN;
        else if (attr->index == SHOW_TJMAX)
                err = sprintf(buf, "%d\n", data->tjmax);
        else
                err = sprintf(buf, "%d\n", data->ttarget);
        return err;
}

static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, show_temp, NULL,
                          SHOW_TEMP);
static SENSOR_DEVICE_ATTR(temp1_crit, S_IRUGO, show_temp, NULL,
                          SHOW_TJMAX);
static SENSOR_DEVICE_ATTR(temp1_max, S_IRUGO, show_temp, NULL,
                          SHOW_TTARGET);
static DEVICE_ATTR(temp1_crit_alarm, S_IRUGO, show_alarm, NULL);
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 *coretemp_attributes[] = {
        &sensor_dev_attr_name.dev_attr.attr,
        &sensor_dev_attr_temp1_label.dev_attr.attr,
        &dev_attr_temp1_crit_alarm.attr,
        &sensor_dev_attr_temp1_input.dev_attr.attr,
        &sensor_dev_attr_temp1_crit.dev_attr.attr,
        NULL
};

static const struct attribute_group coretemp_group = {
        .attrs = coretemp_attributes,
};

static struct coretemp_data *coretemp_update_device(struct device *dev)
{
        struct coretemp_data *data = dev_get_drvdata(dev);

        mutex_lock(&data->update_lock);

        if (!data->valid || time_after(jiffies, data->last_updated + HZ)) {
                u32 eax, edx;

                data->valid = 0;
                rdmsr_on_cpu(data->id, MSR_IA32_THERM_STATUS, &eax, &edx);
                data->alarm = (eax >> 5) & 1;
                /* update only if data has been valid */
                if (eax & 0x80000000) {
                        data->temp = data->tjmax - (((eax >> 16)
                                                        & 0x7f) * 1000);
                        data->valid = 1;
                } else {
                        dev_dbg(dev, "Temperature data invalid (0x%x)\n", eax);
                }
                data->last_updated = jiffies;
        }

        mutex_unlock(&data->update_lock);
        return data;
}

static int __devinit adjust_tjmax(struct cpuinfo_x86 *c, u32 id, struct device *dev)
{
        /* The 100C is default for both mobile and non mobile CPUs */

        int tjmax = 100000;
        int tjmax_ee = 85000;
        int usemsr_ee = 1;
        int err;
        u32 eax, edx;
        struct pci_dev *host_bridge;

        /* Early chips have no MSR for TjMax */

        if ((c->x86_model == 0xf) && (c->x86_mask < 4)) {
                usemsr_ee = 0;
        }

        /* Atom CPUs */

        if (c->x86_model == 0x1c) {
                usemsr_ee = 0;

                host_bridge = pci_get_bus_and_slot(0, PCI_DEVFN(0, 0));

                if (host_bridge && host_bridge->vendor == PCI_VENDOR_ID_INTEL
                    && (host_bridge->device == 0xa000   /* NM10 based nettop */
                    || host_bridge->device == 0xa010))  /* NM10 based netbook */
                        tjmax = 100000;
                else
                        tjmax = 90000;

                pci_dev_put(host_bridge);
        }

        if ((c->x86_model > 0xe) && (usemsr_ee)) {
                u8 platform_id;

                /* Now we can detect the mobile CPU using Intel provided table
                   http://softwarecommunity.intel.com/Wiki/Mobility/720.htm
                   For Core2 cores, check MSR 0x17, bit 28 1 = Mobile CPU
                */

                err = rdmsr_safe_on_cpu(id, 0x17, &eax, &edx);
                if (err) {
                        dev_warn(dev,
                                 "Unable to access MSR 0x17, assuming desktop"
                                 " CPU\n");
                        usemsr_ee = 0;
                } else if (c->x86_model < 0x17 && !(eax & 0x10000000)) {
                        /* Trust bit 28 up to Penryn, I could not find any
                           documentation on that; if you happen to know
                           someone at Intel please ask */
                        usemsr_ee = 0;
                } else {
                        /* Platform ID bits 52:50 (EDX starts at bit 32) */
                        platform_id = (edx >> 18) & 0x7;

                        /* Mobile Penryn CPU seems to be platform ID 7 or 5
                          (guesswork) */
                        if ((c->x86_model == 0x17) &&
                            ((platform_id == 5) || (platform_id == 7))) {
                                /* If MSR EE bit is set, set it to 90 degrees C,
                                   otherwise 105 degrees C */
                                tjmax_ee = 90000;
                                tjmax = 105000;
                        }
                }
        }

        if (usemsr_ee) {

                err = rdmsr_safe_on_cpu(id, 0xee, &eax, &edx);
                if (err) {
                        dev_warn(dev,
                                 "Unable to access MSR 0xEE, for Tjmax, left"
                                 " at default\n");
                } else if (eax & 0x40000000) {
                        tjmax = tjmax_ee;
                }
        /* if we dont use msr EE it means we are desktop CPU (with exeception
           of Atom) */
        } else if (tjmax == 100000) {
                dev_warn(dev, "Using relative temperature scale!\n");
        }

        return tjmax;
}

static int __devinit coretemp_probe(struct platform_device *pdev)
{
        struct coretemp_data *data;
        struct cpuinfo_x86 *c = &cpu_data(pdev->id);
        int err;
        u32 eax, edx;

        if (!(data = kzalloc(sizeof(struct coretemp_data), GFP_KERNEL))) {
                err = -ENOMEM;
                dev_err(&pdev->dev, "Out of memory\n");
                goto exit;
        }

        data->id = pdev->id;
        data->name = "coretemp";
        mutex_init(&data->update_lock);

        /* test if we can access the THERM_STATUS MSR */
        err = rdmsr_safe_on_cpu(data->id, MSR_IA32_THERM_STATUS, &eax, &edx);
        if (err) {
                dev_err(&pdev->dev,
                        "Unable to access THERM_STATUS MSR, giving up\n");
                goto exit_free;
        }

        /* Check if we have problem with errata AE18 of Core processors:
           Readings might stop update when processor visited too deep sleep,
           fixed for stepping D0 (6EC).
        */

        if ((c->x86_model == 0xe) && (c->x86_mask < 0xc)) {
                /* check for microcode update */
                rdmsr_on_cpu(data->id, MSR_IA32_UCODE_REV, &eax, &edx);
                if (edx < 0x39) {
                        err = -ENODEV;
                        dev_err(&pdev->dev,
                                "Errata AE18 not fixed, update BIOS or "
                                "microcode of the CPU!\n");
                        goto exit_free;
                }
        }

        data->tjmax = adjust_tjmax(c, data->id, &pdev->dev);
        platform_set_drvdata(pdev, data);

        /* read the still undocumented IA32_TEMPERATURE_TARGET it exists
           on older CPUs but not in this register, Atoms don't have it either */

        if ((c->x86_model > 0xe) && (c->x86_model != 0x1c)) {
                err = rdmsr_safe_on_cpu(data->id, 0x1a2, &eax, &edx);
                if (err) {
                        dev_warn(&pdev->dev, "Unable to read"
                                        " IA32_TEMPERATURE_TARGET MSR\n");
                } else {
                        data->ttarget = data->tjmax -
                                        (((eax >> 8) & 0xff) * 1000);
                        err = device_create_file(&pdev->dev,
                                        &sensor_dev_attr_temp1_max.dev_attr);
                        if (err)
                                goto exit_free;
                }
        }

        if ((err = sysfs_create_group(&pdev->dev.kobj, &coretemp_group)))
                goto exit_dev;

        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_class;
        }

        return 0;

exit_class:
        sysfs_remove_group(&pdev->dev.kobj, &coretemp_group);
exit_dev:
        device_remove_file(&pdev->dev, &sensor_dev_attr_temp1_max.dev_attr);
exit_free:
        kfree(data);
exit:
        return err;
}

static int __devexit coretemp_remove(struct platform_device *pdev)
{
        struct coretemp_data *data = platform_get_drvdata(pdev);

        hwmon_device_unregister(data->hwmon_dev);
        sysfs_remove_group(&pdev->dev.kobj, &coretemp_group);
        device_remove_file(&pdev->dev, &sensor_dev_attr_temp1_max.dev_attr);
        platform_set_drvdata(pdev, NULL);
        kfree(data);
        return 0;
}

static struct platform_driver coretemp_driver = {
        .driver = {
                .owner = THIS_MODULE,
                .name = DRVNAME,
        },
        .probe = coretemp_probe,
        .remove = __devexit_p(coretemp_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 coretemp_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 coretemp_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 coretemp_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:
                coretemp_device_add(cpu);
                break;
        case CPU_DOWN_PREPARE:
                coretemp_device_remove(cpu);
                break;
        }
        return NOTIFY_OK;
}

static struct notifier_block coretemp_cpu_notifier __refdata = {
        .notifier_call = coretemp_cpu_callback,
};
#endif                          /* !CONFIG_HOTPLUG_CPU */

static int __init coretemp_init(void)
{
        int i, err = -ENODEV;
        struct pdev_entry *p, *n;

        /* quick check if we run Intel */
        if (cpu_data(0).x86_vendor != X86_VENDOR_INTEL)
                goto exit;

        err = platform_driver_register(&coretemp_driver);
        if (err)
                goto exit;

        for_each_online_cpu(i) {
                struct cpuinfo_x86 *c = &cpu_data(i);

                /* check if family 6, models 0xe (Pentium M DC),
                  0xf (Core 2 DC 65nm), 0x16 (Core 2 SC 65nm),
                  0x17 (Penryn 45nm), 0x1a (Nehalem), 0x1c (Atom),
                  0x1e (Lynnfield) */
                if ((c->cpuid_level < 0) || (c->x86 != 0x6) ||
                    !((c->x86_model == 0xe) || (c->x86_model == 0xf) ||
                        (c->x86_model == 0x16) || (c->x86_model == 0x17) ||
                        (c->x86_model == 0x1a) || (c->x86_model == 0x1c) ||
                        (c->x86_model == 0x1e))) {

                        /* supported CPU not found, but report the unknown
                           family 6 CPU */
                        if ((c->x86 == 0x6) && (c->x86_model > 0xf))
                                printk(KERN_WARNING DRVNAME ": Unknown CPU "
                                        "model 0x%x\n", c->x86_model);
                        continue;
                }

                err = coretemp_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(&coretemp_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(&coretemp_driver);
exit:
        return err;
}

static void __exit coretemp_exit(void)
{
        struct pdev_entry *p, *n;
#ifdef CONFIG_HOTPLUG_CPU
        unregister_hotcpu_notifier(&coretemp_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(&coretemp_driver);
}

MODULE_AUTHOR("Rudolf Marek <r.marek@assembler.cz>");
MODULE_DESCRIPTION("Intel Core temperature monitor");
MODULE_LICENSE("GPL");

module_init(coretemp_init)
module_exit(coretemp_exit)