summaryrefslogtreecommitdiffstats
path: root/drivers/media/cec/cec-notifier.c
blob: 74dc1c32080eaf8d57d837fb93ab6587992e0483 (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
/*
 * cec-notifier.c - notify CEC drivers of physical address changes
 *
 * Copyright 2016 Russell King <rmk+kernel@arm.linux.org.uk>
 * Copyright 2016-2017 Cisco Systems, Inc. and/or its affiliates. All rights reserved.
 *
 * This program is free software; you may redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; version 2 of the License.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
 * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
 * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
 * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 * SOFTWARE.
 */

#include <linux/export.h>
#include <linux/string.h>
#include <linux/slab.h>
#include <linux/list.h>
#include <linux/kref.h>

#include <media/cec.h>
#include <media/cec-notifier.h>
#include <drm/drm_edid.h>

struct cec_notifier {
	struct mutex lock;
	struct list_head head;
	struct kref kref;
	struct device *dev;
	struct cec_adapter *cec_adap;
	void (*callback)(struct cec_adapter *adap, u16 pa);

	u16 phys_addr;
};

static LIST_HEAD(cec_notifiers);
static DEFINE_MUTEX(cec_notifiers_lock);

struct cec_notifier *cec_notifier_get(struct device *dev)
{
	struct cec_notifier *n;

	mutex_lock(&cec_notifiers_lock);
	list_for_each_entry(n, &cec_notifiers, head) {
		if (n->dev == dev) {
			kref_get(&n->kref);
			mutex_unlock(&cec_notifiers_lock);
			return n;
		}
	}
	n = kzalloc(sizeof(*n), GFP_KERNEL);
	if (!n)
		goto unlock;
	n->dev = dev;
	n->phys_addr = CEC_PHYS_ADDR_INVALID;
	mutex_init(&n->lock);
	kref_init(&n->kref);
	list_add_tail(&n->head, &cec_notifiers);
unlock:
	mutex_unlock(&cec_notifiers_lock);
	return n;
}
EXPORT_SYMBOL_GPL(cec_notifier_get);

static void cec_notifier_release(struct kref *kref)
{
	struct cec_notifier *n =
		container_of(kref, struct cec_notifier, kref);

	list_del(&n->head);
	kfree(n);
}

void cec_notifier_put(struct cec_notifier *n)
{
	mutex_lock(&cec_notifiers_lock);
	kref_put(&n->kref, cec_notifier_release);
	mutex_unlock(&cec_notifiers_lock);
}
EXPORT_SYMBOL_GPL(cec_notifier_put);

void cec_notifier_set_phys_addr(struct cec_notifier *n, u16 pa)
{
	mutex_lock(&n->lock);
	n->phys_addr = pa;
	if (n->callback)
		n->callback(n->cec_adap, n->phys_addr);
	mutex_unlock(&n->lock);
}
EXPORT_SYMBOL_GPL(cec_notifier_set_phys_addr);

void cec_notifier_set_phys_addr_from_edid(struct cec_notifier *n,
					  const struct edid *edid)
{
	u16 pa = CEC_PHYS_ADDR_INVALID;

	if (edid && edid->extensions)
		pa = cec_get_edid_phys_addr((const u8 *)edid,
				EDID_LENGTH * (edid->extensions + 1), NULL);
	cec_notifier_set_phys_addr(n, pa);
}
EXPORT_SYMBOL_GPL(cec_notifier_set_phys_addr_from_edid);

void cec_notifier_register(struct cec_notifier *n,
			   struct cec_adapter *adap,
			   void (*callback)(struct cec_adapter *adap, u16 pa))
{
	kref_get(&n->kref);
	mutex_lock(&n->lock);
	n->cec_adap = adap;
	n->callback = callback;
	n->callback(adap, n->phys_addr);
	mutex_unlock(&n->lock);
}
EXPORT_SYMBOL_GPL(cec_notifier_register);

void cec_notifier_unregister(struct cec_notifier *n)
{
	mutex_lock(&n->lock);
	n->callback = NULL;
	mutex_unlock(&n->lock);
	cec_notifier_put(n);
}
EXPORT_SYMBOL_GPL(cec_notifier_unregister);