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
22struct fsl_mpic_timer_wakeup {
23	struct mpic_timer *timer;
24	struct work_struct free_work;
25};
26
27static struct fsl_mpic_timer_wakeup *fsl_wakeup;
28static DEFINE_MUTEX(sysfs_lock);
29
30static 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
46static 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
55static 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
72static 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
120static struct device_attribute mpic_attributes = __ATTR(timer_wakeup, 0644,
121			fsl_timer_wakeup_show, fsl_timer_wakeup_store);
122
123static 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
140static 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
156module_init(fsl_wakeup_sys_init);
157module_exit(fsl_wakeup_sys_exit);
158
159MODULE_DESCRIPTION("Freescale MPIC global timer wakeup driver");
160MODULE_LICENSE("GPL v2");
161MODULE_AUTHOR("Wang Dongsheng <dongsheng.wang@freescale.com>");
162