1 /*
2 * MPIC timer wakeup driver
3 *
4 * Copyright 2013 Freescale Semiconductor, Inc.
5 *
6 * This program is free software; you can redistribute it and/or modify it
7 * under the terms of the GNU General Public License as published by the
8 * Free Software Foundation; either version 2 of the License, or (at your
9 * option) any later version.
10 */
11
12 #include <linux/kernel.h>
13 #include <linux/slab.h>
14 #include <linux/errno.h>
15 #include <linux/module.h>
16 #include <linux/interrupt.h>
17 #include <linux/device.h>
18
19 #include <asm/mpic_timer.h>
20 #include <asm/mpic.h>
21
22 struct fsl_mpic_timer_wakeup {
23 struct mpic_timer *timer;
24 struct work_struct free_work;
25 };
26
27 static struct fsl_mpic_timer_wakeup *fsl_wakeup;
28 static DEFINE_MUTEX(sysfs_lock);
29
fsl_free_resource(struct work_struct * ws)30 static void fsl_free_resource(struct work_struct *ws)
31 {
32 struct fsl_mpic_timer_wakeup *wakeup =
33 container_of(ws, struct fsl_mpic_timer_wakeup, free_work);
34
35 mutex_lock(&sysfs_lock);
36
37 if (wakeup->timer) {
38 disable_irq_wake(wakeup->timer->irq);
39 mpic_free_timer(wakeup->timer);
40 }
41
42 wakeup->timer = NULL;
43 mutex_unlock(&sysfs_lock);
44 }
45
fsl_mpic_timer_irq(int irq,void * dev_id)46 static irqreturn_t fsl_mpic_timer_irq(int irq, void *dev_id)
47 {
48 struct fsl_mpic_timer_wakeup *wakeup = dev_id;
49
50 schedule_work(&wakeup->free_work);
51
52 return wakeup->timer ? IRQ_HANDLED : IRQ_NONE;
53 }
54
fsl_timer_wakeup_show(struct device * dev,struct device_attribute * attr,char * buf)55 static ssize_t fsl_timer_wakeup_show(struct device *dev,
56 struct device_attribute *attr,
57 char *buf)
58 {
59 time64_t interval = 0;
60
61 mutex_lock(&sysfs_lock);
62 if (fsl_wakeup->timer) {
63 mpic_get_remain_time(fsl_wakeup->timer, &interval);
64 interval++;
65 }
66 mutex_unlock(&sysfs_lock);
67
68 return sprintf(buf, "%lld\n", interval);
69 }
70
fsl_timer_wakeup_store(struct device * dev,struct device_attribute * attr,const char * buf,size_t count)71 static ssize_t fsl_timer_wakeup_store(struct device *dev,
72 struct device_attribute *attr,
73 const char *buf,
74 size_t count)
75 {
76 time64_t interval;
77 int ret;
78
79 if (kstrtoll(buf, 0, &interval))
80 return -EINVAL;
81
82 mutex_lock(&sysfs_lock);
83
84 if (fsl_wakeup->timer) {
85 disable_irq_wake(fsl_wakeup->timer->irq);
86 mpic_free_timer(fsl_wakeup->timer);
87 fsl_wakeup->timer = NULL;
88 }
89
90 if (!interval) {
91 mutex_unlock(&sysfs_lock);
92 return count;
93 }
94
95 fsl_wakeup->timer = mpic_request_timer(fsl_mpic_timer_irq,
96 fsl_wakeup, interval);
97 if (!fsl_wakeup->timer) {
98 mutex_unlock(&sysfs_lock);
99 return -EINVAL;
100 }
101
102 ret = enable_irq_wake(fsl_wakeup->timer->irq);
103 if (ret) {
104 mpic_free_timer(fsl_wakeup->timer);
105 fsl_wakeup->timer = NULL;
106 mutex_unlock(&sysfs_lock);
107
108 return ret;
109 }
110
111 mpic_start_timer(fsl_wakeup->timer);
112
113 mutex_unlock(&sysfs_lock);
114
115 return count;
116 }
117
118 static struct device_attribute mpic_attributes = __ATTR(timer_wakeup, 0644,
119 fsl_timer_wakeup_show, fsl_timer_wakeup_store);
120
fsl_wakeup_sys_init(void)121 static int __init fsl_wakeup_sys_init(void)
122 {
123 int ret;
124
125 fsl_wakeup = kzalloc(sizeof(struct fsl_mpic_timer_wakeup), GFP_KERNEL);
126 if (!fsl_wakeup)
127 return -ENOMEM;
128
129 INIT_WORK(&fsl_wakeup->free_work, fsl_free_resource);
130
131 ret = device_create_file(mpic_subsys.dev_root, &mpic_attributes);
132 if (ret)
133 kfree(fsl_wakeup);
134
135 return ret;
136 }
137
fsl_wakeup_sys_exit(void)138 static void __exit fsl_wakeup_sys_exit(void)
139 {
140 device_remove_file(mpic_subsys.dev_root, &mpic_attributes);
141
142 mutex_lock(&sysfs_lock);
143
144 if (fsl_wakeup->timer) {
145 disable_irq_wake(fsl_wakeup->timer->irq);
146 mpic_free_timer(fsl_wakeup->timer);
147 }
148
149 kfree(fsl_wakeup);
150
151 mutex_unlock(&sysfs_lock);
152 }
153
154 module_init(fsl_wakeup_sys_init);
155 module_exit(fsl_wakeup_sys_exit);
156
157 MODULE_DESCRIPTION("Freescale MPIC global timer wakeup driver");
158 MODULE_LICENSE("GPL v2");
159 MODULE_AUTHOR("Wang Dongsheng <dongsheng.wang@freescale.com>");
160
