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/* Copyright (c) 2016, The Linux Foundation. All rights reserved.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 and
* only 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.
*/
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/of.h>
#include <linux/cpu.h>
#include <linux/sysfs.h>
#include <linux/kobject.h>
#include <linux/spinlock.h>
#include <linux/slab.h>
#include <soc/qcom/irq-helper.h>
struct irq_helper {
bool enable;
bool deploy;
uint32_t count;
struct kobject kobj;
/* spinlock to protect reference count variable 'count' */
spinlock_t lock;
};
struct irq_helper_attr {
struct attribute attr;
ssize_t (*show)(struct kobject *kobj, struct attribute *attr,
char *buf);
size_t (*store)(struct kobject *kobj, struct attribute *attr,
const char *buf, size_t count);
};
#define IRQ_HELPER_ATTR(_name, _mode, _show, _store) \
struct irq_helper_attr irq_helper_##_name = \
__ATTR(_name, _mode, _show, _store)
#define to_irq_helper(kobj) \
container_of(kobj, struct irq_helper, kobj)
#define to_irq_helper_attr(_attr) \
container_of(_attr, struct irq_helper_attr, attr)
static ssize_t attr_show(struct kobject *kobj, struct attribute *attr,
char *buf)
{
struct irq_helper_attr *irq_attr = to_irq_helper_attr(attr);
ssize_t ret = -EIO;
if (irq_attr->show)
ret = irq_attr->show(kobj, attr, buf);
return ret;
}
static const struct sysfs_ops irq_helper_sysfs_ops = {
.show = attr_show,
};
static struct kobj_type irq_helper_ktype = {
.sysfs_ops = &irq_helper_sysfs_ops,
};
static ssize_t show_deploy(struct kobject *kobj, struct attribute *attr,
char *buf)
{
struct irq_helper *irq = to_irq_helper(kobj);
return snprintf(buf, PAGE_SIZE, "%u\n", irq->deploy);
}
IRQ_HELPER_ATTR(irq_blacklist_on, 0444, show_deploy, NULL);
static struct irq_helper *irq_h;
/* Do not call this API in an atomic context */
int irq_blacklist_on(void)
{
bool flag = false;
might_sleep();
if (!irq_h) {
pr_err("%s: init function is not called", __func__);
return -EPERM;
}
if (!irq_h->enable) {
pr_err("%s: enable bit is not set up", __func__);
return -EPERM;
}
spin_lock(&irq_h->lock);
irq_h->count++;
if (!irq_h->deploy) {
irq_h->deploy = true;
flag = true;
}
spin_unlock(&irq_h->lock);
if (flag)
sysfs_notify(&irq_h->kobj, NULL, "irq_blacklist_on");
return 0;
}
EXPORT_SYMBOL(irq_blacklist_on);
/* Do not call this API in an atomic context */
int irq_blacklist_off(void)
{
bool flag = false;
might_sleep();
if (!irq_h) {
pr_err("%s: init function is not called", __func__);
return -EPERM;
}
if (!irq_h->enable) {
pr_err("%s: enable bit is not set up", __func__);
return -EPERM;
}
spin_lock(&irq_h->lock);
if (irq_h->count == 0) {
pr_err("%s: ref-count is 0, cannot call irq blacklist off.",
__func__);
spin_unlock(&irq_h->lock);
return -EPERM;
}
irq_h->count--;
if (irq_h->count == 0) {
irq_h->deploy = false;
flag = true;
}
spin_unlock(&irq_h->lock);
if (flag)
sysfs_notify(&irq_h->kobj, NULL, "irq_blacklist_on");
return 0;
}
EXPORT_SYMBOL(irq_blacklist_off);
static int __init irq_helper_init(void)
{
int ret;
irq_h = kzalloc(sizeof(struct irq_helper), GFP_KERNEL);
if (!irq_h)
return -ENOMEM;
ret = kobject_init_and_add(&irq_h->kobj, &irq_helper_ktype,
kernel_kobj, "%s", "irq_helper");
if (ret) {
pr_err("%s:Error in creation kobject_add\n", __func__);
goto out_free_irq;
}
ret = sysfs_create_file(&irq_h->kobj,
&irq_helper_irq_blacklist_on.attr);
if (ret) {
pr_err("%s:Error in sysfs_create_file\n", __func__);
goto out_put_kobj;
}
spin_lock_init(&irq_h->lock);
irq_h->count = 0;
irq_h->enable = true;
return 0;
out_put_kobj:
kobject_put(&irq_h->kobj);
out_free_irq:
kfree(irq_h);
return ret;
}
module_init(irq_helper_init);
static void __exit irq_helper_exit(void)
{
sysfs_remove_file(&irq_h->kobj, &irq_helper_irq_blacklist_on.attr);
kobject_del(&irq_h->kobj);
kobject_put(&irq_h->kobj);
kfree(irq_h);
}
module_exit(irq_helper_exit);
MODULE_DESCRIPTION("IRQ Helper APIs");
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