linux/drivers/hwmon/via-cputemp.c
Sebastian Andrzej Siewior df60d7013c hwmon: (via-cputemp) Convert to hotplug state machine
Install the callbacks via the state machine and let the core invoke the
callbacks on the already online CPUs. When the hotplug state is
unregistered the cleanup function is called for each cpu. So both cpu loops
in init() and exit() are not longer required.

Cc: Jean Delvare <jdelvare@suse.com>
Cc: Guenter Roeck <linux@roeck-us.net>
Cc: linux-hwmon@vger.kernel.org
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
2016-12-09 21:54:27 -08:00

339 lines
7.6 KiB
C

/*
* 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.
*/
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
#include <linux/module.h>
#include <linux/init.h>
#include <linux/slab.h>
#include <linux/hwmon.h>
#include <linux/hwmon-vid.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>
#include <asm/cpu_device_id.h>
#define DRVNAME "via_cputemp"
enum { SHOW_TEMP, SHOW_LABEL, SHOW_NAME };
/*
* Functions declaration
*/
struct via_cputemp_data {
struct device *hwmon_dev;
const char *name;
u8 vrm;
u32 id;
u32 msr_temp;
u32 msr_vid;
};
/*
* 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_temp, &eax, &edx);
if (err)
return -EAGAIN;
return sprintf(buf, "%lu\n", ((unsigned long)eax & 0xffffff) * 1000);
}
static ssize_t show_cpu_vid(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_vid, &eax, &edx);
if (err)
return -EAGAIN;
return sprintf(buf, "%d\n", vid_from_reg(~edx & 0x7f, data->vrm));
}
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,
};
/* Optional attributes */
static DEVICE_ATTR(cpu0_vid, S_IRUGO, show_cpu_vid, NULL);
static int 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 = devm_kzalloc(&pdev->dev, sizeof(struct via_cputemp_data),
GFP_KERNEL);
if (!data)
return -ENOMEM;
data->id = pdev->id;
data->name = "via_cputemp";
switch (c->x86_model) {
case 0xA:
/* C7 A */
case 0xD:
/* C7 D */
data->msr_temp = 0x1169;
data->msr_vid = 0x198;
break;
case 0xF:
/* Nano */
data->msr_temp = 0x1423;
break;
default:
return -ENODEV;
}
/* test if we can access the TEMPERATURE MSR */
err = rdmsr_safe_on_cpu(data->id, data->msr_temp, &eax, &edx);
if (err) {
dev_err(&pdev->dev,
"Unable to access TEMPERATURE MSR, giving up\n");
return err;
}
platform_set_drvdata(pdev, data);
err = sysfs_create_group(&pdev->dev.kobj, &via_cputemp_group);
if (err)
return err;
if (data->msr_vid)
data->vrm = vid_which_vrm();
if (data->vrm) {
err = device_create_file(&pdev->dev, &dev_attr_cpu0_vid);
if (err)
goto exit_remove;
}
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:
if (data->vrm)
device_remove_file(&pdev->dev, &dev_attr_cpu0_vid);
sysfs_remove_group(&pdev->dev.kobj, &via_cputemp_group);
return err;
}
static int via_cputemp_remove(struct platform_device *pdev)
{
struct via_cputemp_data *data = platform_get_drvdata(pdev);
hwmon_device_unregister(data->hwmon_dev);
if (data->vrm)
device_remove_file(&pdev->dev, &dev_attr_cpu0_vid);
sysfs_remove_group(&pdev->dev.kobj, &via_cputemp_group);
return 0;
}
static struct platform_driver via_cputemp_driver = {
.driver = {
.name = DRVNAME,
},
.probe = via_cputemp_probe,
.remove = 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 via_cputemp_online(unsigned int cpu)
{
int err;
struct platform_device *pdev;
struct pdev_entry *pdev_entry;
pdev = platform_device_alloc(DRVNAME, cpu);
if (!pdev) {
err = -ENOMEM;
pr_err("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) {
pr_err("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;
}
static int via_cputemp_down_prep(unsigned int cpu)
{
struct pdev_entry *p;
mutex_lock(&pdev_list_mutex);
list_for_each_entry(p, &pdev_list, list) {
if (p->cpu == cpu) {
platform_device_unregister(p->pdev);
list_del(&p->list);
mutex_unlock(&pdev_list_mutex);
kfree(p);
return 0;
}
}
mutex_unlock(&pdev_list_mutex);
return 0;
}
static const struct x86_cpu_id __initconst cputemp_ids[] = {
{ X86_VENDOR_CENTAUR, 6, 0xa, }, /* C7 A */
{ X86_VENDOR_CENTAUR, 6, 0xd, }, /* C7 D */
{ X86_VENDOR_CENTAUR, 6, 0xf, }, /* Nano */
{}
};
MODULE_DEVICE_TABLE(x86cpu, cputemp_ids);
static enum cpuhp_state via_temp_online;
static int __init via_cputemp_init(void)
{
int err;
if (!x86_match_cpu(cputemp_ids))
return -ENODEV;
err = platform_driver_register(&via_cputemp_driver);
if (err)
goto exit;
err = cpuhp_setup_state(CPUHP_AP_ONLINE_DYN, "hwmon/via:online",
via_cputemp_online, via_cputemp_down_prep);
if (err < 0)
goto exit_driver_unreg;
via_temp_online = err;
#ifndef CONFIG_HOTPLUG_CPU
if (list_empty(&pdev_list)) {
err = -ENODEV;
goto exit_hp_unreg;
}
#endif
return 0;
#ifndef CONFIG_HOTPLUG_CPU
exit_hp_unreg:
cpuhp_remove_state_nocalls(via_temp_online);
#endif
exit_driver_unreg:
platform_driver_unregister(&via_cputemp_driver);
exit:
return err;
}
static void __exit via_cputemp_exit(void)
{
cpuhp_remove_state(via_temp_online);
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)