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
18 struct fsl_mpic_timer_wakeup {
19 struct mpic_timer *timer;
20 struct work_struct free_work;
21 };
22
23 static struct fsl_mpic_timer_wakeup *fsl_wakeup;
24 static DEFINE_MUTEX(sysfs_lock);
25
fsl_free_resource(struct work_struct * ws)26 static 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(wakeup->timer->irq);
35 mpic_free_timer(wakeup->timer);
36 }
37
38 wakeup->timer = NULL;
39 mutex_unlock(&sysfs_lock);
40 }
41
fsl_mpic_timer_irq(int irq,void * dev_id)42 static 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(&wakeup->free_work);
47
48 return wakeup->timer ? IRQ_HANDLED : IRQ_NONE;
49 }
50
fsl_timer_wakeup_show(struct device * dev,struct device_attribute * attr,char * buf)51 static 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(&sysfs_lock);
63
64 return sprintf(buf, "%lld\n", interval);
65 }
66
fsl_timer_wakeup_store(struct device * dev,struct device_attribute * attr,const char * buf,size_t count)67 static 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(buf, 0, &interval))
76 return -EINVAL;
77
78 mutex_lock(&sysfs_lock);
79
80 if (fsl_wakeup->timer) {
81 disable_irq_wake(fsl_wakeup->timer->irq);
82 mpic_free_timer(fsl_wakeup->timer);
83 fsl_wakeup->timer = NULL;
84 }
85
86 if (!interval) {
87 mutex_unlock(&sysfs_lock);
88 return count;
89 }
90
91 fsl_wakeup->timer = mpic_request_timer(fsl_mpic_timer_irq,
92 fsl_wakeup, interval);
93 if (!fsl_wakeup->timer) {
94 mutex_unlock(&sysfs_lock);
95 return -EINVAL;
96 }
97
98 ret = enable_irq_wake(fsl_wakeup->timer->irq);
99 if (ret) {
100 mpic_free_timer(fsl_wakeup->timer);
101 fsl_wakeup->timer = NULL;
102 mutex_unlock(&sysfs_lock);
103
104 return ret;
105 }
106
107 mpic_start_timer(fsl_wakeup->timer);
108
109 mutex_unlock(&sysfs_lock);
110
111 return count;
112 }
113
114 static struct device_attribute mpic_attributes = __ATTR(timer_wakeup, 0644,
115 fsl_timer_wakeup_show, fsl_timer_wakeup_store);
116
fsl_wakeup_sys_init(void)117 static int __init fsl_wakeup_sys_init(void)
118 {
119 int ret;
120
121 fsl_wakeup = kzalloc(sizeof(struct fsl_mpic_timer_wakeup), GFP_KERNEL);
122 if (!fsl_wakeup)
123 return -ENOMEM;
124
125 INIT_WORK(&fsl_wakeup->free_work, fsl_free_resource);
126
127 ret = device_create_file(mpic_subsys.dev_root, &mpic_attributes);
128 if (ret)
129 kfree(fsl_wakeup);
130
131 return ret;
132 }
133
fsl_wakeup_sys_exit(void)134 static void __exit fsl_wakeup_sys_exit(void)
135 {
136 device_remove_file(mpic_subsys.dev_root, &mpic_attributes);
137
138 mutex_lock(&sysfs_lock);
139
140 if (fsl_wakeup->timer) {
141 disable_irq_wake(fsl_wakeup->timer->irq);
142 mpic_free_timer(fsl_wakeup->timer);
143 }
144
145 kfree(fsl_wakeup);
146
147 mutex_unlock(&sysfs_lock);
148 }
149
150 module_init(fsl_wakeup_sys_init);
151 module_exit(fsl_wakeup_sys_exit);
152
153 MODULE_DESCRIPTION("Freescale MPIC global timer wakeup driver");
154 MODULE_LICENSE("GPL v2");
155 MODULE_AUTHOR("Wang Dongsheng <dongsheng.wang@freescale.com>");
156