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Linux kernel mirror (for testing)
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1/*
2 * cec - HDMI Consumer Electronics Control support header
3 *
4 * Copyright 2016 Cisco Systems, Inc. and/or its affiliates. All rights reserved.
5 *
6 * This program is free software; you may redistribute it and/or modify
7 * it under the terms of the GNU General Public License as published by
8 * the Free Software Foundation; version 2 of the License.
9 *
10 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
11 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
12 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
13 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
14 * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
15 * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
16 * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
17 * SOFTWARE.
18 */
19
20#ifndef _MEDIA_CEC_H
21#define _MEDIA_CEC_H
22
23#include <linux/poll.h>
24#include <linux/fs.h>
25#include <linux/debugfs.h>
26#include <linux/device.h>
27#include <linux/cdev.h>
28#include <linux/kthread.h>
29#include <linux/timer.h>
30#include <linux/cec-funcs.h>
31#include <media/rc-core.h>
32#include <media/cec-edid.h>
33
34/**
35 * struct cec_devnode - cec device node
36 * @dev: cec device
37 * @cdev: cec character device
38 * @parent: parent device
39 * @minor: device node minor number
40 * @registered: the device was correctly registered
41 * @unregistered: the device was unregistered
42 * @fhs_lock: lock to control access to the filehandle list
43 * @fhs: the list of open filehandles (cec_fh)
44 *
45 * This structure represents a cec-related device node.
46 *
47 * The @parent is a physical device. It must be set by core or device drivers
48 * before registering the node.
49 */
50struct cec_devnode {
51 /* sysfs */
52 struct device dev;
53 struct cdev cdev;
54 struct device *parent;
55
56 /* device info */
57 int minor;
58 bool registered;
59 bool unregistered;
60 struct mutex fhs_lock;
61 struct list_head fhs;
62};
63
64struct cec_adapter;
65struct cec_data;
66
67struct cec_data {
68 struct list_head list;
69 struct list_head xfer_list;
70 struct cec_adapter *adap;
71 struct cec_msg msg;
72 struct cec_fh *fh;
73 struct delayed_work work;
74 struct completion c;
75 u8 attempts;
76 bool new_initiator;
77 bool blocking;
78 bool completed;
79};
80
81struct cec_msg_entry {
82 struct list_head list;
83 struct cec_msg msg;
84};
85
86#define CEC_NUM_EVENTS CEC_EVENT_LOST_MSGS
87
88struct cec_fh {
89 struct list_head list;
90 struct list_head xfer_list;
91 struct cec_adapter *adap;
92 u8 mode_initiator;
93 u8 mode_follower;
94
95 /* Events */
96 wait_queue_head_t wait;
97 unsigned int pending_events;
98 struct cec_event events[CEC_NUM_EVENTS];
99 struct mutex lock;
100 struct list_head msgs; /* queued messages */
101 unsigned int queued_msgs;
102};
103
104#define CEC_SIGNAL_FREE_TIME_RETRY 3
105#define CEC_SIGNAL_FREE_TIME_NEW_INITIATOR 5
106#define CEC_SIGNAL_FREE_TIME_NEXT_XFER 7
107
108/* The nominal data bit period is 2.4 ms */
109#define CEC_FREE_TIME_TO_USEC(ft) ((ft) * 2400)
110
111struct cec_adap_ops {
112 /* Low-level callbacks */
113 int (*adap_enable)(struct cec_adapter *adap, bool enable);
114 int (*adap_monitor_all_enable)(struct cec_adapter *adap, bool enable);
115 int (*adap_log_addr)(struct cec_adapter *adap, u8 logical_addr);
116 int (*adap_transmit)(struct cec_adapter *adap, u8 attempts,
117 u32 signal_free_time, struct cec_msg *msg);
118 void (*adap_status)(struct cec_adapter *adap, struct seq_file *file);
119
120 /* High-level CEC message callback */
121 int (*received)(struct cec_adapter *adap, struct cec_msg *msg);
122};
123
124/*
125 * The minimum message length you can receive (excepting poll messages) is 2.
126 * With a transfer rate of at most 36 bytes per second this makes 18 messages
127 * per second worst case.
128 *
129 * We queue at most 3 seconds worth of received messages. The CEC specification
130 * requires that messages are replied to within a second, so 3 seconds should
131 * give more than enough margin. Since most messages are actually more than 2
132 * bytes, this is in practice a lot more than 3 seconds.
133 */
134#define CEC_MAX_MSG_RX_QUEUE_SZ (18 * 3)
135
136/*
137 * The transmit queue is limited to 1 second worth of messages (worst case).
138 * Messages can be transmitted by userspace and kernel space. But for both it
139 * makes no sense to have a lot of messages queued up. One second seems
140 * reasonable.
141 */
142#define CEC_MAX_MSG_TX_QUEUE_SZ (18 * 1)
143
144struct cec_adapter {
145 struct module *owner;
146 char name[32];
147 struct cec_devnode devnode;
148 struct mutex lock;
149 struct rc_dev *rc;
150
151 struct list_head transmit_queue;
152 unsigned int transmit_queue_sz;
153 struct list_head wait_queue;
154 struct cec_data *transmitting;
155
156 struct task_struct *kthread_config;
157 struct completion config_completion;
158
159 struct task_struct *kthread;
160 wait_queue_head_t kthread_waitq;
161 wait_queue_head_t waitq;
162
163 const struct cec_adap_ops *ops;
164 void *priv;
165 u32 capabilities;
166 u8 available_log_addrs;
167
168 u16 phys_addr;
169 bool is_configuring;
170 bool is_configured;
171 u32 monitor_all_cnt;
172 u32 follower_cnt;
173 struct cec_fh *cec_follower;
174 struct cec_fh *cec_initiator;
175 bool passthrough;
176 struct cec_log_addrs log_addrs;
177
178 struct dentry *cec_dir;
179 struct dentry *status_file;
180
181 u16 phys_addrs[15];
182 u32 sequence;
183
184 char input_name[32];
185 char input_phys[32];
186 char input_drv[32];
187};
188
189static inline bool cec_has_log_addr(const struct cec_adapter *adap, u8 log_addr)
190{
191 return adap->log_addrs.log_addr_mask & (1 << log_addr);
192}
193
194static inline bool cec_is_sink(const struct cec_adapter *adap)
195{
196 return adap->phys_addr == 0;
197}
198
199#if IS_ENABLED(CONFIG_MEDIA_CEC)
200struct cec_adapter *cec_allocate_adapter(const struct cec_adap_ops *ops,
201 void *priv, const char *name, u32 caps, u8 available_las,
202 struct device *parent);
203int cec_register_adapter(struct cec_adapter *adap);
204void cec_unregister_adapter(struct cec_adapter *adap);
205void cec_delete_adapter(struct cec_adapter *adap);
206
207int cec_s_log_addrs(struct cec_adapter *adap, struct cec_log_addrs *log_addrs,
208 bool block);
209void cec_s_phys_addr(struct cec_adapter *adap, u16 phys_addr,
210 bool block);
211int cec_transmit_msg(struct cec_adapter *adap, struct cec_msg *msg,
212 bool block);
213
214/* Called by the adapter */
215void cec_transmit_done(struct cec_adapter *adap, u8 status, u8 arb_lost_cnt,
216 u8 nack_cnt, u8 low_drive_cnt, u8 error_cnt);
217void cec_received_msg(struct cec_adapter *adap, struct cec_msg *msg);
218
219#else
220
221static inline int cec_register_adapter(struct cec_adapter *adap)
222{
223 return 0;
224}
225
226static inline void cec_unregister_adapter(struct cec_adapter *adap)
227{
228}
229
230static inline void cec_delete_adapter(struct cec_adapter *adap)
231{
232}
233
234static inline void cec_s_phys_addr(struct cec_adapter *adap, u16 phys_addr,
235 bool block)
236{
237}
238
239#endif
240
241#endif /* _MEDIA_CEC_H */