linux/drivers/hwmon/via-cputemp.c
Uwe Kleine-König 88ac8226a3 hwmon: (via-cputemp) Convert to platform remove callback returning void
The .remove() callback for a platform driver returns an int which makes
many driver authors wrongly assume it's possible to do error handling by
returning an error code. However the value returned is ignored (apart
from emitting a warning) and this typically results in resource leaks.
To improve here there is a quest to make the remove callback return
void. In the first step of this quest all drivers are converted to
.remove_new() which already returns void. Eventually after all drivers
are converted, .remove_new() is renamed to .remove().

Trivially convert this driver from always returning zero in the remove
callback to the void returning variant.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Link: https://lore.kernel.org/r/20230918085951.1234172-19-u.kleine-koenig@pengutronix.de
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
2023-10-27 07:27:25 -07:00

329 lines
7.1 KiB
C

// SPDX-License-Identifier: GPL-2.0-only
/*
* 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>
*/
#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 name_show(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 temp_show(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 cpu0_vid_show(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_RO(temp1_input, temp, SHOW_TEMP);
static SENSOR_DEVICE_ATTR_RO(temp1_label, name, SHOW_LABEL);
static SENSOR_DEVICE_ATTR_RO(name, name, 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_RO(cpu0_vid);
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";
if (c->x86 == 7) {
data->msr_temp = 0x1423;
} else {
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 void 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);
}
static struct platform_driver via_cputemp_driver = {
.driver = {
.name = DRVNAME,
},
.probe = via_cputemp_probe,
.remove_new = 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_MATCH_VENDOR_FAM_MODEL(CENTAUR, 6, X86_CENTAUR_FAM6_C7_A, NULL),
X86_MATCH_VENDOR_FAM_MODEL(CENTAUR, 6, X86_CENTAUR_FAM6_C7_D, NULL),
X86_MATCH_VENDOR_FAM_MODEL(CENTAUR, 6, X86_CENTAUR_FAM6_NANO, NULL),
X86_MATCH_VENDOR_FAM_MODEL(CENTAUR, 7, X86_MODEL_ANY, NULL),
{}
};
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)