linux/drivers/hwmon/vexpress.c
Pawel Moll b2e5411ee2 hwmon: (vexpress) Avoid creating non-existing attributes
The 'label' attribute was always created but returned -ENOENT
if there is no label and such behaviour is undefined from
libsensors' point of view.

Fixed by providing is_visible method in the attributes group,
so the attribute is not created at all when unnecessary.

Reported-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Pawel Moll <pawel.moll@arm.com>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
2014-04-24 06:02:10 -07:00

290 lines
7.9 KiB
C

/*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*
* 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.
*
* Copyright (C) 2012 ARM Limited
*/
#define DRVNAME "vexpress-hwmon"
#define pr_fmt(fmt) DRVNAME ": " fmt
#include <linux/device.h>
#include <linux/err.h>
#include <linux/hwmon.h>
#include <linux/hwmon-sysfs.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/of_device.h>
#include <linux/platform_device.h>
#include <linux/vexpress.h>
struct vexpress_hwmon_data {
struct device *hwmon_dev;
struct vexpress_config_func *func;
const char *name;
};
static ssize_t vexpress_hwmon_name_show(struct device *dev,
struct device_attribute *dev_attr, char *buffer)
{
struct vexpress_hwmon_data *data = dev_get_drvdata(dev);
return sprintf(buffer, "%s\n", data->name);
}
static ssize_t vexpress_hwmon_label_show(struct device *dev,
struct device_attribute *dev_attr, char *buffer)
{
const char *label = of_get_property(dev->of_node, "label", NULL);
return snprintf(buffer, PAGE_SIZE, "%s\n", label);
}
static ssize_t vexpress_hwmon_u32_show(struct device *dev,
struct device_attribute *dev_attr, char *buffer)
{
struct vexpress_hwmon_data *data = dev_get_drvdata(dev);
int err;
u32 value;
err = vexpress_config_read(data->func, 0, &value);
if (err)
return err;
return snprintf(buffer, PAGE_SIZE, "%u\n", value /
to_sensor_dev_attr(dev_attr)->index);
}
static ssize_t vexpress_hwmon_u64_show(struct device *dev,
struct device_attribute *dev_attr, char *buffer)
{
struct vexpress_hwmon_data *data = dev_get_drvdata(dev);
int err;
u32 value_hi, value_lo;
err = vexpress_config_read(data->func, 0, &value_lo);
if (err)
return err;
err = vexpress_config_read(data->func, 1, &value_hi);
if (err)
return err;
return snprintf(buffer, PAGE_SIZE, "%llu\n",
div_u64(((u64)value_hi << 32) | value_lo,
to_sensor_dev_attr(dev_attr)->index));
}
static umode_t vexpress_hwmon_attr_is_visible(struct kobject *kobj,
struct attribute *attr, int index)
{
struct device *dev = kobj_to_dev(kobj);
struct device_attribute *dev_attr = container_of(attr,
struct device_attribute, attr);
if (dev_attr->show == vexpress_hwmon_label_show &&
!of_get_property(dev->of_node, "label", NULL))
return 0;
return attr->mode;
}
static DEVICE_ATTR(name, S_IRUGO, vexpress_hwmon_name_show, NULL);
#define VEXPRESS_HWMON_ATTRS(_name, _label_attr, _input_attr) \
struct attribute *vexpress_hwmon_attrs_##_name[] = { \
&dev_attr_name.attr, \
&dev_attr_##_label_attr.attr, \
&sensor_dev_attr_##_input_attr.dev_attr.attr, \
NULL \
}
struct vexpress_hwmon_type {
const char *name;
const struct attribute_group **attr_groups;
};
#if !defined(CONFIG_REGULATOR_VEXPRESS)
static DEVICE_ATTR(in1_label, S_IRUGO, vexpress_hwmon_label_show, NULL);
static SENSOR_DEVICE_ATTR(in1_input, S_IRUGO, vexpress_hwmon_u32_show,
NULL, 1000);
static VEXPRESS_HWMON_ATTRS(volt, in1_label, in1_input);
static struct attribute_group vexpress_hwmon_group_volt = {
.is_visible = vexpress_hwmon_attr_is_visible,
.attrs = vexpress_hwmon_attrs_volt,
};
static struct vexpress_hwmon_type vexpress_hwmon_volt = {
.name = "vexpress_volt",
.attr_groups = (const struct attribute_group *[]) {
&vexpress_hwmon_group_volt,
NULL,
},
};
#endif
static DEVICE_ATTR(curr1_label, S_IRUGO, vexpress_hwmon_label_show, NULL);
static SENSOR_DEVICE_ATTR(curr1_input, S_IRUGO, vexpress_hwmon_u32_show,
NULL, 1000);
static VEXPRESS_HWMON_ATTRS(amp, curr1_label, curr1_input);
static struct attribute_group vexpress_hwmon_group_amp = {
.is_visible = vexpress_hwmon_attr_is_visible,
.attrs = vexpress_hwmon_attrs_amp,
};
static struct vexpress_hwmon_type vexpress_hwmon_amp = {
.name = "vexpress_amp",
.attr_groups = (const struct attribute_group *[]) {
&vexpress_hwmon_group_amp,
NULL
},
};
static DEVICE_ATTR(temp1_label, S_IRUGO, vexpress_hwmon_label_show, NULL);
static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, vexpress_hwmon_u32_show,
NULL, 1000);
static VEXPRESS_HWMON_ATTRS(temp, temp1_label, temp1_input);
static struct attribute_group vexpress_hwmon_group_temp = {
.is_visible = vexpress_hwmon_attr_is_visible,
.attrs = vexpress_hwmon_attrs_temp,
};
static struct vexpress_hwmon_type vexpress_hwmon_temp = {
.name = "vexpress_temp",
.attr_groups = (const struct attribute_group *[]) {
&vexpress_hwmon_group_temp,
NULL
},
};
static DEVICE_ATTR(power1_label, S_IRUGO, vexpress_hwmon_label_show, NULL);
static SENSOR_DEVICE_ATTR(power1_input, S_IRUGO, vexpress_hwmon_u32_show,
NULL, 1);
static VEXPRESS_HWMON_ATTRS(power, power1_label, power1_input);
static struct attribute_group vexpress_hwmon_group_power = {
.is_visible = vexpress_hwmon_attr_is_visible,
.attrs = vexpress_hwmon_attrs_power,
};
static struct vexpress_hwmon_type vexpress_hwmon_power = {
.name = "vexpress_power",
.attr_groups = (const struct attribute_group *[]) {
&vexpress_hwmon_group_power,
NULL
},
};
static DEVICE_ATTR(energy1_label, S_IRUGO, vexpress_hwmon_label_show, NULL);
static SENSOR_DEVICE_ATTR(energy1_input, S_IRUGO, vexpress_hwmon_u64_show,
NULL, 1);
static VEXPRESS_HWMON_ATTRS(energy, energy1_label, energy1_input);
static struct attribute_group vexpress_hwmon_group_energy = {
.is_visible = vexpress_hwmon_attr_is_visible,
.attrs = vexpress_hwmon_attrs_energy,
};
static struct vexpress_hwmon_type vexpress_hwmon_energy = {
.name = "vexpress_energy",
.attr_groups = (const struct attribute_group *[]) {
&vexpress_hwmon_group_energy,
NULL
},
};
static struct of_device_id vexpress_hwmon_of_match[] = {
#if !defined(CONFIG_REGULATOR_VEXPRESS)
{
.compatible = "arm,vexpress-volt",
.data = &vexpress_hwmon_volt,
},
#endif
{
.compatible = "arm,vexpress-amp",
.data = &vexpress_hwmon_amp,
}, {
.compatible = "arm,vexpress-temp",
.data = &vexpress_hwmon_temp,
}, {
.compatible = "arm,vexpress-power",
.data = &vexpress_hwmon_power,
}, {
.compatible = "arm,vexpress-energy",
.data = &vexpress_hwmon_energy,
},
{}
};
MODULE_DEVICE_TABLE(of, vexpress_hwmon_of_match);
static int vexpress_hwmon_probe(struct platform_device *pdev)
{
int err;
const struct of_device_id *match;
struct vexpress_hwmon_data *data;
const struct vexpress_hwmon_type *type;
data = devm_kzalloc(&pdev->dev, sizeof(*data), GFP_KERNEL);
if (!data)
return -ENOMEM;
platform_set_drvdata(pdev, data);
match = of_match_device(vexpress_hwmon_of_match, &pdev->dev);
if (!match)
return -ENODEV;
type = match->data;
data->name = type->name;
data->func = vexpress_config_func_get_by_dev(&pdev->dev);
if (!data->func)
return -ENODEV;
err = sysfs_create_groups(&pdev->dev.kobj, type->attr_groups);
if (err)
goto error;
data->hwmon_dev = hwmon_device_register(&pdev->dev);
if (IS_ERR(data->hwmon_dev)) {
err = PTR_ERR(data->hwmon_dev);
goto error;
}
return 0;
error:
sysfs_remove_group(&pdev->dev.kobj, match->data);
vexpress_config_func_put(data->func);
return err;
}
static int vexpress_hwmon_remove(struct platform_device *pdev)
{
struct vexpress_hwmon_data *data = platform_get_drvdata(pdev);
const struct of_device_id *match;
hwmon_device_unregister(data->hwmon_dev);
match = of_match_device(vexpress_hwmon_of_match, &pdev->dev);
sysfs_remove_group(&pdev->dev.kobj, match->data);
vexpress_config_func_put(data->func);
return 0;
}
static struct platform_driver vexpress_hwmon_driver = {
.probe = vexpress_hwmon_probe,
.remove = vexpress_hwmon_remove,
.driver = {
.name = DRVNAME,
.owner = THIS_MODULE,
.of_match_table = vexpress_hwmon_of_match,
},
};
module_platform_driver(vexpress_hwmon_driver);
MODULE_AUTHOR("Pawel Moll <pawel.moll@arm.com>");
MODULE_DESCRIPTION("Versatile Express hwmon sensors driver");
MODULE_LICENSE("GPL");
MODULE_ALIAS("platform:vexpress-hwmon");