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/*
* Copyright (C) ST-Ericsson SA 2011
*
* Author: Lee Jones <lee.jones@linaro.org> for ST-Ericsson.
* License terms: GNU General Public License (GPL), version 2
*/
#include <linux/sysfs.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/stat.h>
#include <linux/slab.h>
#include <linux/idr.h>
#include <linux/spinlock.h>
#include <linux/sys_soc.h>
#include <linux/err.h>
static DEFINE_IDA(soc_ida);
static DEFINE_SPINLOCK(soc_lock);
static ssize_t soc_info_get(struct device *dev,
struct device_attribute *attr,
char *buf);
struct soc_device {
struct device dev;
struct soc_device_attribute *attr;
int soc_dev_num;
};
static struct bus_type soc_bus_type = {
.name = "soc",
};
static DEVICE_ATTR(machine, S_IRUGO, soc_info_get, NULL);
static DEVICE_ATTR(family, S_IRUGO, soc_info_get, NULL);
static DEVICE_ATTR(soc_id, S_IRUGO, soc_info_get, NULL);
static DEVICE_ATTR(revision, S_IRUGO, soc_info_get, NULL);
struct device *soc_device_to_device(struct soc_device *soc_dev)
{
return &soc_dev->dev;
}
static mode_t soc_attribute_mode(struct kobject *kobj,
struct attribute *attr,
int index)
{
struct device *dev = container_of(kobj, struct device, kobj);
struct soc_device *soc_dev = container_of(dev, struct soc_device, dev);
if ((attr == &dev_attr_machine.attr)
&& (soc_dev->attr->machine != NULL))
return attr->mode;
if ((attr == &dev_attr_family.attr)
&& (soc_dev->attr->family != NULL))
return attr->mode;
if ((attr == &dev_attr_revision.attr)
&& (soc_dev->attr->revision != NULL))
return attr->mode;
if ((attr == &dev_attr_soc_id.attr)
&& (soc_dev->attr->soc_id != NULL))
return attr->mode;
/* Unknown or unfilled attribute. */
return 0;
}
static ssize_t soc_info_get(struct device *dev,
struct device_attribute *attr,
char *buf)
{
struct soc_device *soc_dev = container_of(dev, struct soc_device, dev);
if (attr == &dev_attr_machine)
return sprintf(buf, "%s\n", soc_dev->attr->machine);
if (attr == &dev_attr_family)
return sprintf(buf, "%s\n", soc_dev->attr->family);
if (attr == &dev_attr_revision)
return sprintf(buf, "%s\n", soc_dev->attr->revision);
if (attr == &dev_attr_soc_id)
return sprintf(buf, "%s\n", soc_dev->attr->soc_id);
return -EINVAL;
}
static struct attribute *soc_attr[] = {
&dev_attr_machine.attr,
&dev_attr_family.attr,
&dev_attr_soc_id.attr,
&dev_attr_revision.attr,
NULL,
};
static const struct attribute_group soc_attr_group = {
.attrs = soc_attr,
.is_visible = soc_attribute_mode,
};
static const struct attribute_group *soc_attr_groups[] = {
&soc_attr_group,
NULL,
};
static void soc_release(struct device *dev)
{
struct soc_device *soc_dev = container_of(dev, struct soc_device, dev);
kfree(soc_dev);
}
struct soc_device *soc_device_register(struct soc_device_attribute *soc_dev_attr)
{
struct soc_device *soc_dev;
int ret;
soc_dev = kzalloc(sizeof(*soc_dev), GFP_KERNEL);
if (!soc_dev) {
ret = -ENOMEM;
goto out1;
}
/* Fetch a unique (reclaimable) SOC ID. */
do {
if (!ida_pre_get(&soc_ida, GFP_KERNEL)) {
ret = -ENOMEM;
goto out2;
}
spin_lock(&soc_lock);
ret = ida_get_new(&soc_ida, &soc_dev->soc_dev_num);
spin_unlock(&soc_lock);
} while (ret == -EAGAIN);
if (ret)
goto out2;
soc_dev->attr = soc_dev_attr;
soc_dev->dev.bus = &soc_bus_type;
soc_dev->dev.groups = soc_attr_groups;
soc_dev->dev.release = soc_release;
dev_set_name(&soc_dev->dev, "soc%d", soc_dev->soc_dev_num);
ret = device_register(&soc_dev->dev);
if (ret)
goto out3;
return soc_dev;
out3:
ida_remove(&soc_ida, soc_dev->soc_dev_num);
out2:
kfree(soc_dev);
out1:
return ERR_PTR(ret);
}
/* Ensure soc_dev->attr is freed prior to calling soc_device_unregister. */
void soc_device_unregister(struct soc_device *soc_dev)
{
ida_remove(&soc_ida, soc_dev->soc_dev_num);
device_unregister(&soc_dev->dev);
}
static int __init soc_bus_register(void)
{
return bus_register(&soc_bus_type);
}
core_initcall(soc_bus_register);
static void __exit soc_bus_unregister(void)
{
ida_destroy(&soc_ida);
bus_unregister(&soc_bus_type);
}
module_exit(soc_bus_unregister);
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