aboutsummaryrefslogtreecommitdiff
path: root/include/media/cec.h
blob: fdb5d600e4bb98a5c09c42aef4bed3715641f6fc (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
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
/*
 * cec - HDMI Consumer Electronics Control support header
 *
 * Copyright 2016 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.
 */

#ifndef _MEDIA_CEC_H
#define _MEDIA_CEC_H

#include <linux/poll.h>
#include <linux/fs.h>
#include <linux/debugfs.h>
#include <linux/device.h>
#include <linux/cdev.h>
#include <linux/kthread.h>
#include <linux/timer.h>
#include <linux/cec-funcs.h>
#include <media/rc-core.h>
#include <media/cec-edid.h>

/**
 * struct cec_devnode - cec device node
 * @dev:	cec device
 * @cdev:	cec character device
 * @parent:	parent device
 * @minor:	device node minor number
 * @registered:	the device was correctly registered
 * @unregistered: the device was unregistered
 * @fhs_lock:	lock to control access to the filehandle list
 * @fhs:	the list of open filehandles (cec_fh)
 *
 * This structure represents a cec-related device node.
 *
 * The @parent is a physical device. It must be set by core or device drivers
 * before registering the node.
 */
struct cec_devnode {
	/* sysfs */
	struct device dev;
	struct cdev cdev;
	struct device *parent;

	/* device info */
	int minor;
	bool registered;
	bool unregistered;
	struct list_head fhs;
	struct mutex lock;
};

struct cec_adapter;
struct cec_data;

struct cec_data {
	struct list_head list;
	struct list_head xfer_list;
	struct cec_adapter *adap;
	struct cec_msg msg;
	struct cec_fh *fh;
	struct delayed_work work;
	struct completion c;
	u8 attempts;
	bool new_initiator;
	bool blocking;
	bool completed;
};

struct cec_msg_entry {
	struct list_head	list;
	struct cec_msg		msg;
};

#define CEC_NUM_EVENTS		CEC_EVENT_LOST_MSGS

struct cec_fh {
	struct list_head	list;
	struct list_head	xfer_list;
	struct cec_adapter	*adap;
	u8			mode_initiator;
	u8			mode_follower;

	/* Events */
	wait_queue_head_t	wait;
	unsigned int		pending_events;
	struct cec_event	events[CEC_NUM_EVENTS];
	struct mutex		lock;
	struct list_head	msgs; /* queued messages */
	unsigned int		queued_msgs;
};

#define CEC_SIGNAL_FREE_TIME_RETRY		3
#define CEC_SIGNAL_FREE_TIME_NEW_INITIATOR	5
#define CEC_SIGNAL_FREE_TIME_NEXT_XFER		7

/* The nominal data bit period is 2.4 ms */
#define CEC_FREE_TIME_TO_USEC(ft)		((ft) * 2400)

struct cec_adap_ops {
	/* Low-level callbacks */
	int (*adap_enable)(struct cec_adapter *adap, bool enable);
	int (*adap_monitor_all_enable)(struct cec_adapter *adap, bool enable);
	int (*adap_log_addr)(struct cec_adapter *adap, u8 logical_addr);
	int (*adap_transmit)(struct cec_adapter *adap, u8 attempts,
			     u32 signal_free_time, struct cec_msg *msg);
	void (*adap_status)(struct cec_adapter *adap, struct seq_file *file);

	/* High-level CEC message callback */
	int (*received)(struct cec_adapter *adap, struct cec_msg *msg);
};

/*
 * The minimum message length you can receive (excepting poll messages) is 2.
 * With a transfer rate of at most 36 bytes per second this makes 18 messages
 * per second worst case.
 *
 * We queue at most 3 seconds worth of received messages. The CEC specification
 * requires that messages are replied to within a second, so 3 seconds should
 * give more than enough margin. Since most messages are actually more than 2
 * bytes, this is in practice a lot more than 3 seconds.
 */
#define CEC_MAX_MSG_RX_QUEUE_SZ		(18 * 3)

/*
 * The transmit queue is limited to 1 second worth of messages (worst case).
 * Messages can be transmitted by userspace and kernel space. But for both it
 * makes no sense to have a lot of messages queued up. One second seems
 * reasonable.
 */
#define CEC_MAX_MSG_TX_QUEUE_SZ		(18 * 1)

struct cec_adapter {
	struct module *owner;
	char name[32];
	struct cec_devnode devnode;
	struct mutex lock;
	struct rc_dev *rc;

	struct list_head transmit_queue;
	unsigned int transmit_queue_sz;
	struct list_head wait_queue;
	struct cec_data *transmitting;

	struct task_struct *kthread_config;
	struct completion config_completion;

	struct task_struct *kthread;
	wait_queue_head_t kthread_waitq;
	wait_queue_head_t waitq;

	const struct cec_adap_ops *ops;
	void *priv;
	u32 capabilities;
	u8 available_log_addrs;

	u16 phys_addr;
	bool is_configuring;
	bool is_configured;
	u32 monitor_all_cnt;
	u32 follower_cnt;
	struct cec_fh *cec_follower;
	struct cec_fh *cec_initiator;
	bool passthrough;
	struct cec_log_addrs log_addrs;

	struct dentry *cec_dir;
	struct dentry *status_file;

	u16 phys_addrs[15];
	u32 sequence;

	char input_name[32];
	char input_phys[32];
	char input_drv[32];
};

static inline bool cec_has_log_addr(const struct cec_adapter *adap, u8 log_addr)
{
	return adap->log_addrs.log_addr_mask & (1 << log_addr);
}

static inline bool cec_is_sink(const struct cec_adapter *adap)
{
	return adap->phys_addr == 0;
}

#if IS_ENABLED(CONFIG_MEDIA_CEC)
struct cec_adapter *cec_allocate_adapter(const struct cec_adap_ops *ops,
		void *priv, const char *name, u32 caps, u8 available_las,
		struct device *parent);
int cec_register_adapter(struct cec_adapter *adap);
void cec_unregister_adapter(struct cec_adapter *adap);
void cec_delete_adapter(struct cec_adapter *adap);

int cec_s_log_addrs(struct cec_adapter *adap, struct cec_log_addrs *log_addrs,
		    bool block);
void cec_s_phys_addr(struct cec_adapter *adap, u16 phys_addr,
		     bool block);
int cec_transmit_msg(struct cec_adapter *adap, struct cec_msg *msg,
		     bool block);

/* Called by the adapter */
void cec_transmit_done(struct cec_adapter *adap, u8 status, u8 arb_lost_cnt,
		       u8 nack_cnt, u8 low_drive_cnt, u8 error_cnt);
void cec_received_msg(struct cec_adapter *adap, struct cec_msg *msg);

#else

static inline int cec_register_adapter(struct cec_adapter *adap)
{
	return 0;
}

static inline void cec_unregister_adapter(struct cec_adapter *adap)
{
}

static inline void cec_delete_adapter(struct cec_adapter *adap)
{
}

static inline void cec_s_phys_addr(struct cec_adapter *adap, u16 phys_addr,
				   bool block)
{
}

#endif

#endif /* _MEDIA_CEC_H */