1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * MPIC timer wakeup driver
4 *
5 * Copyright 2013 Freescale Semiconductor, Inc.
6 */
7
8#include <linux/kernel.h>
9#include <linux/slab.h>
10#include <linux/errno.h>
11#include <linux/module.h>
12#include <linux/interrupt.h>
13#include <linux/device.h>
14
15#include <asm/mpic_timer.h>
16#include <asm/mpic.h>
17
18struct fsl_mpic_timer_wakeup {
19 struct mpic_timer *timer;
20 struct work_struct free_work;
21};
22
23static struct fsl_mpic_timer_wakeup *fsl_wakeup;
24static DEFINE_MUTEX(sysfs_lock);
25
26static void fsl_free_resource(struct work_struct *ws)
27{
28 struct fsl_mpic_timer_wakeup *wakeup =
29 container_of(ws, struct fsl_mpic_timer_wakeup, free_work);
30
31 mutex_lock(&sysfs_lock);
32
33 if (wakeup->timer) {
34 disable_irq_wake(irq: wakeup->timer->irq);
35 mpic_free_timer(wakeup->timer);
36 }
37
38 wakeup->timer = NULL;
39 mutex_unlock(lock: &sysfs_lock);
40}
41
42static irqreturn_t fsl_mpic_timer_irq(int irq, void *dev_id)
43{
44 struct fsl_mpic_timer_wakeup *wakeup = dev_id;
45
46 schedule_work(work: &wakeup->free_work);
47
48 return wakeup->timer ? IRQ_HANDLED : IRQ_NONE;
49}
50
51static ssize_t fsl_timer_wakeup_show(struct device *dev,
52 struct device_attribute *attr,
53 char *buf)
54{
55 time64_t interval = 0;
56
57 mutex_lock(&sysfs_lock);
58 if (fsl_wakeup->timer) {
59 mpic_get_remain_time(fsl_wakeup->timer, &interval);
60 interval++;
61 }
62 mutex_unlock(lock: &sysfs_lock);
63
64 return sprintf(buf, fmt: "%lld\n", interval);
65}
66
67static ssize_t fsl_timer_wakeup_store(struct device *dev,
68 struct device_attribute *attr,
69 const char *buf,
70 size_t count)
71{
72 time64_t interval;
73 int ret;
74
75 if (kstrtoll(s: buf, base: 0, res: &interval))
76 return -EINVAL;
77
78 guard(mutex)(T: &sysfs_lock);
79
80 if (fsl_wakeup->timer) {
81 disable_irq_wake(irq: fsl_wakeup->timer->irq);
82 mpic_free_timer(fsl_wakeup->timer);
83 fsl_wakeup->timer = NULL;
84 }
85
86 if (!interval)
87 return count;
88
89 fsl_wakeup->timer = mpic_request_timer(fsl_mpic_timer_irq,
90 fsl_wakeup, interval);
91 if (!fsl_wakeup->timer)
92 return -EINVAL;
93
94 ret = enable_irq_wake(irq: fsl_wakeup->timer->irq);
95 if (ret) {
96 mpic_free_timer(fsl_wakeup->timer);
97 fsl_wakeup->timer = NULL;
98 return ret;
99 }
100
101 mpic_start_timer(fsl_wakeup->timer);
102
103 return count;
104}
105
106static struct device_attribute mpic_attributes = __ATTR(timer_wakeup, 0644,
107 fsl_timer_wakeup_show, fsl_timer_wakeup_store);
108
109static int __init fsl_wakeup_sys_init(void)
110{
111 struct device *dev_root;
112 int ret = -EINVAL;
113
114 fsl_wakeup = kzalloc(sizeof(struct fsl_mpic_timer_wakeup), GFP_KERNEL);
115 if (!fsl_wakeup)
116 return -ENOMEM;
117
118 INIT_WORK(&fsl_wakeup->free_work, fsl_free_resource);
119
120 dev_root = bus_get_dev_root(bus: &mpic_subsys);
121 if (dev_root) {
122 ret = device_create_file(device: dev_root, entry: &mpic_attributes);
123 put_device(dev: dev_root);
124 if (ret)
125 kfree(objp: fsl_wakeup);
126 }
127
128 return ret;
129}
130
131static void __exit fsl_wakeup_sys_exit(void)
132{
133 struct device *dev_root;
134
135 dev_root = bus_get_dev_root(bus: &mpic_subsys);
136 if (dev_root) {
137 device_remove_file(dev: dev_root, attr: &mpic_attributes);
138 put_device(dev: dev_root);
139 }
140
141 mutex_lock(&sysfs_lock);
142
143 if (fsl_wakeup->timer) {
144 disable_irq_wake(irq: fsl_wakeup->timer->irq);
145 mpic_free_timer(fsl_wakeup->timer);
146 }
147
148 kfree(objp: fsl_wakeup);
149
150 mutex_unlock(lock: &sysfs_lock);
151}
152
153module_init(fsl_wakeup_sys_init);
154module_exit(fsl_wakeup_sys_exit);
155
156MODULE_DESCRIPTION("Freescale MPIC global timer wakeup driver");
157MODULE_LICENSE("GPL v2");
158MODULE_AUTHOR("Wang Dongsheng <dongsheng.wang@freescale.com>");
159

source code of linux/arch/powerpc/sysdev/fsl_mpic_timer_wakeup.c