Commit bab2243c authored by Guenter Roeck's avatar Guenter Roeck
Browse files

hwmon: Introduce hwmon_device_register_with_groups 



hwmon_device_register_with_groups() lets callers register a hwmon device
together with all sysfs attributes in a single call.

When using hwmon_device_register_with_groups(), hwmon attributes are attached
to the hwmon device directly and no longer with its parent device.

Signed-off-by: default avatarGuenter Roeck <linux@roeck-us.net>
parent 522928a8

drivers/hwmon/hwmon.c

+106 −16
Original line number Diff line number Diff line
@@ -15,6 +15,7 @@ 
#include <linux/module.h>

#include <linux/device.h>

#include <linux/err.h>

#include <linux/slab.h>

#include <linux/kdev_t.h>

#include <linux/idr.h>

#include <linux/hwmon.h>
@@ -25,35 +26,122 @@ 
#define HWMON_ID_PREFIX "hwmon"

#define HWMON_ID_FORMAT HWMON_ID_PREFIX "%d"



static struct class *hwmon_class;

struct hwmon_device {

	const char *name;

	struct device dev;

};

#define to_hwmon_device(d) container_of(d, struct hwmon_device, dev)



static ssize_t

show_name(struct device *dev, struct device_attribute *attr, char *buf)

{

	return sprintf(buf, "%s\n", to_hwmon_device(dev)->name);

}

static DEVICE_ATTR(name, S_IRUGO, show_name, NULL);



static struct attribute *hwmon_dev_attrs[] = {

	&dev_attr_name.attr,

	NULL

};



static umode_t hwmon_dev_name_is_visible(struct kobject *kobj,

					 struct attribute *attr, int n)

{

	struct device *dev = container_of(kobj, struct device, kobj);



	if (to_hwmon_device(dev)->name == NULL)

		return 0;



	return attr->mode;

}



static struct attribute_group hwmon_dev_attr_group = {

	.attrs		= hwmon_dev_attrs,

	.is_visible	= hwmon_dev_name_is_visible,

};



static const struct attribute_group *hwmon_dev_attr_groups[] = {

	&hwmon_dev_attr_group,

	NULL

};



static void hwmon_dev_release(struct device *dev)

{

	kfree(to_hwmon_device(dev));

}



static struct class hwmon_class = {

	.name = "hwmon",

	.owner = THIS_MODULE,

	.dev_groups = hwmon_dev_attr_groups,

	.dev_release = hwmon_dev_release,

};



static DEFINE_IDA(hwmon_ida);



/**

 * hwmon_device_register - register w/ hwmon

 * @dev: the device to register

 * hwmon_device_register_with_groups - register w/ hwmon

 * @dev: the parent device

 * @name: hwmon name attribute

 * @drvdata: driver data to attach to created device

 * @groups: List of attribute groups to create

 *

 * hwmon_device_unregister() must be called when the device is no

 * longer needed.

 *

 * Returns the pointer to the new device.

 */

struct device *hwmon_device_register(struct device *dev)

struct device *

hwmon_device_register_with_groups(struct device *dev, const char *name,

				  void *drvdata,

				  const struct attribute_group **groups)

{

	struct device *hwdev;

	int id;

	struct hwmon_device *hwdev;

	int err, id;



	id = ida_simple_get(&hwmon_ida, 0, 0, GFP_KERNEL);

	if (id < 0)

		return ERR_PTR(id);



	hwdev = device_create(hwmon_class, dev, MKDEV(0, 0), NULL,

			      HWMON_ID_FORMAT, id);

	hwdev = kzalloc(sizeof(*hwdev), GFP_KERNEL);

	if (hwdev == NULL) {

		err = -ENOMEM;

		goto ida_remove;

	}



	if (IS_ERR(hwdev))

	hwdev->name = name;

	hwdev->dev.class = &hwmon_class;

	hwdev->dev.parent = dev;

	hwdev->dev.groups = groups;

	hwdev->dev.of_node = dev ? dev->of_node : NULL;

	dev_set_drvdata(&hwdev->dev, drvdata);

	dev_set_name(&hwdev->dev, HWMON_ID_FORMAT, id);

	err = device_register(&hwdev->dev);

	if (err)

		goto free;



	return &hwdev->dev;



free:

	kfree(hwdev);

ida_remove:

	ida_simple_remove(&hwmon_ida, id);

	return ERR_PTR(err);

}

EXPORT_SYMBOL_GPL(hwmon_device_register_with_groups);



	return hwdev;

/**

 * hwmon_device_register - register w/ hwmon

 * @dev: the device to register

 *

 * hwmon_device_unregister() must be called when the device is no

 * longer needed.

 *

 * Returns the pointer to the new device.

 */

struct device *hwmon_device_register(struct device *dev)

{

	return hwmon_device_register_with_groups(dev, NULL, NULL, NULL);

}

EXPORT_SYMBOL_GPL(hwmon_device_register);
@@ -105,19 +193,21 @@ static void __init hwmon_pci_quirks(void) 


static int __init hwmon_init(void)

{

	int err;



	hwmon_pci_quirks();



	hwmon_class = class_create(THIS_MODULE, "hwmon");

	if (IS_ERR(hwmon_class)) {

		pr_err("couldn't create sysfs class\n");

		return PTR_ERR(hwmon_class);

	err = class_register(&hwmon_class);

	if (err) {

		pr_err("couldn't register hwmon sysfs class\n");

		return err;

	}

	return 0;

}



static void __exit hwmon_exit(void)

{

	class_destroy(hwmon_class);

	class_unregister(&hwmon_class);

}



subsys_initcall(hwmon_init);

include/linux/hwmon.h

+5 −0
Original line number Diff line number Diff line
@@ -15,8 +15,13 @@ 
#define _HWMON_H_



struct device;

struct attribute_group;



struct device *hwmon_device_register(struct device *dev);

struct device *

hwmon_device_register_with_groups(struct device *dev, const char *name,

				  void *drvdata,

				  const struct attribute_group **groups);



void hwmon_device_unregister(struct device *dev);