summaryrefslogtreecommitdiffstats
path: root/arch/powerpc/sysdev/fsl_mpic_timer_wakeup.c
blob: 94278e8af1920c5a2d257c24f3c8d005d132ae8e (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
/*
 * MPIC timer wakeup driver
 *
 * Copyright 2013 Freescale Semiconductor, Inc.
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License as published by the
 * Free Software Foundation; either version 2 of the License, or (at your
 * option) any later version.
 */

#include <linux/kernel.h>
#include <linux/slab.h>
#include <linux/errno.h>
#include <linux/module.h>
#include <linux/interrupt.h>
#include <linux/device.h>

#include <asm/mpic_timer.h>
#include <asm/mpic.h>

struct fsl_mpic_timer_wakeup {
	struct mpic_timer *timer;
	struct work_struct free_work;
};

static struct fsl_mpic_timer_wakeup *fsl_wakeup;
static DEFINE_MUTEX(sysfs_lock);

static void fsl_free_resource(struct work_struct *ws)
{
	struct fsl_mpic_timer_wakeup *wakeup =
		container_of(ws, struct fsl_mpic_timer_wakeup, free_work);

	mutex_lock(&sysfs_lock);

	if (wakeup->timer) {
		disable_irq_wake(wakeup->timer->irq);
		mpic_free_timer(wakeup->timer);
	}

	wakeup->timer = NULL;
	mutex_unlock(&sysfs_lock);
}

static irqreturn_t fsl_mpic_timer_irq(int irq, void *dev_id)
{
	struct fsl_mpic_timer_wakeup *wakeup = dev_id;

	schedule_work(&wakeup->free_work);

	return wakeup->timer ? IRQ_HANDLED : IRQ_NONE;
}

static ssize_t fsl_timer_wakeup_show(struct device *dev,
				struct device_attribute *attr,
				char *buf)
{
	time64_t interval = 0;

	mutex_lock(&sysfs_lock);
	if (fsl_wakeup->timer) {
		mpic_get_remain_time(fsl_wakeup->timer, &interval);
		interval++;
	}
	mutex_unlock(&sysfs_lock);

	return sprintf(buf, "%lld\n", interval);
}

static ssize_t fsl_timer_wakeup_store(struct device *dev,
				struct device_attribute *attr,
				const char *buf,
				size_t count)
{
	time64_t interval;
	int ret;

	if (kstrtoll(buf, 0, &interval))
		return -EINVAL;

	mutex_lock(&sysfs_lock);

	if (fsl_wakeup->timer) {
		disable_irq_wake(fsl_wakeup->timer->irq);
		mpic_free_timer(fsl_wakeup->timer);
		fsl_wakeup->timer = NULL;
	}

	if (!interval) {
		mutex_unlock(&sysfs_lock);
		return count;
	}

	fsl_wakeup->timer = mpic_request_timer(fsl_mpic_timer_irq,
						fsl_wakeup, interval);
	if (!fsl_wakeup->timer) {
		mutex_unlock(&sysfs_lock);
		return -EINVAL;
	}

	ret = enable_irq_wake(fsl_wakeup->timer->irq);
	if (ret) {
		mpic_free_timer(fsl_wakeup->timer);
		fsl_wakeup->timer = NULL;
		mutex_unlock(&sysfs_lock);

		return ret;
	}

	mpic_start_timer(fsl_wakeup->timer);

	mutex_unlock(&sysfs_lock);

	return count;
}

static struct device_attribute mpic_attributes = __ATTR(timer_wakeup, 0644,
			fsl_timer_wakeup_show, fsl_timer_wakeup_store);

static int __init fsl_wakeup_sys_init(void)
{
	int ret;

	fsl_wakeup = kzalloc(sizeof(struct fsl_mpic_timer_wakeup), GFP_KERNEL);
	if (!fsl_wakeup)
		return -ENOMEM;

	INIT_WORK(&fsl_wakeup->free_work, fsl_free_resource);

	ret = device_create_file(mpic_subsys.dev_root, &mpic_attributes);
	if (ret)
		kfree(fsl_wakeup);

	return ret;
}

static void __exit fsl_wakeup_sys_exit(void)
{
	device_remove_file(mpic_subsys.dev_root, &mpic_attributes);

	mutex_lock(&sysfs_lock);

	if (fsl_wakeup->timer) {
		disable_irq_wake(fsl_wakeup->timer->irq);
		mpic_free_timer(fsl_wakeup->timer);
	}

	kfree(fsl_wakeup);

	mutex_unlock(&sysfs_lock);
}

module_init(fsl_wakeup_sys_init);
module_exit(fsl_wakeup_sys_exit);

MODULE_DESCRIPTION("Freescale MPIC global timer wakeup driver");
MODULE_LICENSE("GPL v2");
MODULE_AUTHOR("Wang Dongsheng <dongsheng.wang@freescale.com>");
OpenPOWER on IntegriCloud