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 struct timeval interval;
60 int val = 0;
61
62 mutex_lock(&sysfs_lock);
63 if (fsl_wakeup->timer) {
64 mpic_get_remain_time(fsl_wakeup->timer, &interval);
65 val = interval.tv_sec + 1;
66 }
67 mutex_unlock(&sysfs_lock);
68
69 return sprintf(buf, "%d\n", val);
70 }
71
fsl_timer_wakeup_store(struct device * dev,struct device_attribute * attr,const char * buf,size_t count)72 static ssize_t fsl_timer_wakeup_store(struct device *dev,
73 struct device_attribute *attr,
74 const char *buf,
75 size_t count)
76 {
77 struct timeval interval;
78 int ret;
79
80 interval.tv_usec = 0;
81 if (kstrtol(buf, 0, &interval.tv_sec))
82 return -EINVAL;
83
84 mutex_lock(&sysfs_lock);
85
86 if (fsl_wakeup->timer) {
87 disable_irq_wake(fsl_wakeup->timer->irq);
88 mpic_free_timer(fsl_wakeup->timer);
89 fsl_wakeup->timer = NULL;
90 }
91
92 if (!interval.tv_sec) {
93 mutex_unlock(&sysfs_lock);
94 return count;
95 }
96
97 fsl_wakeup->timer = mpic_request_timer(fsl_mpic_timer_irq,
98 fsl_wakeup, &interval);
99 if (!fsl_wakeup->timer) {
100 mutex_unlock(&sysfs_lock);
101 return -EINVAL;
102 }
103
104 ret = enable_irq_wake(fsl_wakeup->timer->irq);
105 if (ret) {
106 mpic_free_timer(fsl_wakeup->timer);
107 fsl_wakeup->timer = NULL;
108 mutex_unlock(&sysfs_lock);
109
110 return ret;
111 }
112
113 mpic_start_timer(fsl_wakeup->timer);
114
115 mutex_unlock(&sysfs_lock);
116
117 return count;
118 }
119
120 static struct device_attribute mpic_attributes = __ATTR(timer_wakeup, 0644,
121 fsl_timer_wakeup_show, fsl_timer_wakeup_store);
122
fsl_wakeup_sys_init(void)123 static int __init fsl_wakeup_sys_init(void)
124 {
125 int ret;
126
127 fsl_wakeup = kzalloc(sizeof(struct fsl_mpic_timer_wakeup), GFP_KERNEL);
128 if (!fsl_wakeup)
129 return -ENOMEM;
130
131 INIT_WORK(&fsl_wakeup->free_work, fsl_free_resource);
132
133 ret = device_create_file(mpic_subsys.dev_root, &mpic_attributes);
134 if (ret)
135 kfree(fsl_wakeup);
136
137 return ret;
138 }
139
fsl_wakeup_sys_exit(void)140 static void __exit fsl_wakeup_sys_exit(void)
141 {
142 device_remove_file(mpic_subsys.dev_root, &mpic_attributes);
143
144 mutex_lock(&sysfs_lock);
145
146 if (fsl_wakeup->timer) {
147 disable_irq_wake(fsl_wakeup->timer->irq);
148 mpic_free_timer(fsl_wakeup->timer);
149 }
150
151 kfree(fsl_wakeup);
152
153 mutex_unlock(&sysfs_lock);
154 }
155
156 module_init(fsl_wakeup_sys_init);
157 module_exit(fsl_wakeup_sys_exit);
158
159 MODULE_DESCRIPTION("Freescale MPIC global timer wakeup driver");
160 MODULE_LICENSE("GPL v2");
161 MODULE_AUTHOR("Wang Dongsheng <dongsheng.wang@freescale.com>");
162