1 /* SPDX-License-Identifier: GPL-2.0-only */
3 * cec - HDMI Consumer Electronics Control support header
5 * Copyright 2016 Cisco Systems, Inc. and/or its affiliates. All rights reserved.
11 #include <linux/poll.h>
13 #include <linux/debugfs.h>
14 #include <linux/device.h>
15 #include <linux/cdev.h>
16 #include <linux/kthread.h>
17 #include <linux/timer.h>
18 #include <linux/cec-funcs.h>
19 #include <media/rc-core.h>
20 #include <media/cec-notifier.h>
22 #define CEC_CAP_DEFAULTS (CEC_CAP_LOG_ADDRS | CEC_CAP_TRANSMIT | \
23 CEC_CAP_PASSTHROUGH | CEC_CAP_RC)
26 * struct cec_devnode - cec device node
28 * @cdev: cec character device
29 * @minor: device node minor number
30 * @registered: the device was correctly registered
31 * @unregistered: the device was unregistered
32 * @fhs_lock: lock to control access to the filehandle list
33 * @fhs: the list of open filehandles (cec_fh)
35 * This structure represents a cec-related device node.
37 * The @parent is a physical device. It must be set by core or device drivers
38 * before registering the node.
58 struct list_head list
;
59 struct list_head xfer_list
;
60 struct cec_adapter
*adap
;
63 struct delayed_work work
;
70 struct cec_msg_entry
{
71 struct list_head list
;
75 struct cec_event_entry
{
76 struct list_head list
;
80 #define CEC_NUM_CORE_EVENTS 2
81 #define CEC_NUM_EVENTS CEC_EVENT_PIN_5V_HIGH
84 struct list_head list
;
85 struct list_head xfer_list
;
86 struct cec_adapter
*adap
;
91 wait_queue_head_t wait
;
93 struct list_head events
[CEC_NUM_EVENTS
]; /* queued events */
94 u16 queued_events
[CEC_NUM_EVENTS
];
95 unsigned int total_queued_events
;
96 struct cec_event_entry core_events
[CEC_NUM_CORE_EVENTS
];
97 struct list_head msgs
; /* queued messages */
98 unsigned int queued_msgs
;
101 #define CEC_SIGNAL_FREE_TIME_RETRY 3
102 #define CEC_SIGNAL_FREE_TIME_NEW_INITIATOR 5
103 #define CEC_SIGNAL_FREE_TIME_NEXT_XFER 7
105 /* The nominal data bit period is 2.4 ms */
106 #define CEC_FREE_TIME_TO_USEC(ft) ((ft) * 2400)
108 struct cec_adap_ops
{
109 /* Low-level callbacks */
110 int (*adap_enable
)(struct cec_adapter
*adap
, bool enable
);
111 int (*adap_monitor_all_enable
)(struct cec_adapter
*adap
, bool enable
);
112 int (*adap_monitor_pin_enable
)(struct cec_adapter
*adap
, bool enable
);
113 int (*adap_log_addr
)(struct cec_adapter
*adap
, u8 logical_addr
);
114 int (*adap_transmit
)(struct cec_adapter
*adap
, u8 attempts
,
115 u32 signal_free_time
, struct cec_msg
*msg
);
116 void (*adap_status
)(struct cec_adapter
*adap
, struct seq_file
*file
);
117 void (*adap_free
)(struct cec_adapter
*adap
);
119 /* Error injection callbacks */
120 int (*error_inj_show
)(struct cec_adapter
*adap
, struct seq_file
*sf
);
121 bool (*error_inj_parse_line
)(struct cec_adapter
*adap
, char *line
);
123 /* High-level CEC message callback */
124 int (*received
)(struct cec_adapter
*adap
, struct cec_msg
*msg
);
128 * The minimum message length you can receive (excepting poll messages) is 2.
129 * With a transfer rate of at most 36 bytes per second this makes 18 messages
130 * per second worst case.
132 * We queue at most 3 seconds worth of received messages. The CEC specification
133 * requires that messages are replied to within a second, so 3 seconds should
134 * give more than enough margin. Since most messages are actually more than 2
135 * bytes, this is in practice a lot more than 3 seconds.
137 #define CEC_MAX_MSG_RX_QUEUE_SZ (18 * 3)
140 * The transmit queue is limited to 1 second worth of messages (worst case).
141 * Messages can be transmitted by userspace and kernel space. But for both it
142 * makes no sense to have a lot of messages queued up. One second seems
145 #define CEC_MAX_MSG_TX_QUEUE_SZ (18 * 1)
148 struct module
*owner
;
150 struct cec_devnode devnode
;
154 struct list_head transmit_queue
;
155 unsigned int transmit_queue_sz
;
156 struct list_head wait_queue
;
157 struct cec_data
*transmitting
;
158 bool transmit_in_progress
;
160 struct task_struct
*kthread_config
;
161 struct completion config_completion
;
163 struct task_struct
*kthread
;
164 wait_queue_head_t kthread_waitq
;
165 wait_queue_head_t waitq
;
167 const struct cec_adap_ops
*ops
;
170 u8 available_log_addrs
;
176 bool cec_pin_is_high
;
181 struct cec_fh
*cec_follower
;
182 struct cec_fh
*cec_initiator
;
184 struct cec_log_addrs log_addrs
;
188 #ifdef CONFIG_CEC_NOTIFIER
189 struct cec_notifier
*notifier
;
191 #ifdef CONFIG_CEC_PIN
195 struct dentry
*cec_dir
;
196 struct dentry
*status_file
;
197 struct dentry
*error_inj_file
;
205 static inline void *cec_get_drvdata(const struct cec_adapter
*adap
)
210 static inline bool cec_has_log_addr(const struct cec_adapter
*adap
, u8 log_addr
)
212 return adap
->log_addrs
.log_addr_mask
& (1 << log_addr
);
215 static inline bool cec_is_sink(const struct cec_adapter
*adap
)
217 return adap
->phys_addr
== 0;
221 * cec_is_registered() - is the CEC adapter registered?
223 * @adap: the CEC adapter, may be NULL.
225 * Return: true if the adapter is registered, false otherwise.
227 static inline bool cec_is_registered(const struct cec_adapter
*adap
)
229 return adap
&& adap
->devnode
.registered
;
232 #define cec_phys_addr_exp(pa) \
233 ((pa) >> 12), ((pa) >> 8) & 0xf, ((pa) >> 4) & 0xf, (pa) & 0xf
237 #if IS_REACHABLE(CONFIG_CEC_CORE)
238 struct cec_adapter
*cec_allocate_adapter(const struct cec_adap_ops
*ops
,
239 void *priv
, const char *name
, u32 caps
, u8 available_las
);
240 int cec_register_adapter(struct cec_adapter
*adap
, struct device
*parent
);
241 void cec_unregister_adapter(struct cec_adapter
*adap
);
242 void cec_delete_adapter(struct cec_adapter
*adap
);
244 int cec_s_log_addrs(struct cec_adapter
*adap
, struct cec_log_addrs
*log_addrs
,
246 void cec_s_phys_addr(struct cec_adapter
*adap
, u16 phys_addr
,
248 void cec_s_phys_addr_from_edid(struct cec_adapter
*adap
,
249 const struct edid
*edid
);
250 int cec_transmit_msg(struct cec_adapter
*adap
, struct cec_msg
*msg
,
253 /* Called by the adapter */
254 void cec_transmit_done_ts(struct cec_adapter
*adap
, u8 status
,
255 u8 arb_lost_cnt
, u8 nack_cnt
, u8 low_drive_cnt
,
256 u8 error_cnt
, ktime_t ts
);
258 static inline void cec_transmit_done(struct cec_adapter
*adap
, u8 status
,
259 u8 arb_lost_cnt
, u8 nack_cnt
,
260 u8 low_drive_cnt
, u8 error_cnt
)
262 cec_transmit_done_ts(adap
, status
, arb_lost_cnt
, nack_cnt
,
263 low_drive_cnt
, error_cnt
, ktime_get());
266 * Simplified version of cec_transmit_done for hardware that doesn't retry
267 * failed transmits. So this is always just one attempt in which case
268 * the status is sufficient.
270 void cec_transmit_attempt_done_ts(struct cec_adapter
*adap
,
271 u8 status
, ktime_t ts
);
273 static inline void cec_transmit_attempt_done(struct cec_adapter
*adap
,
276 cec_transmit_attempt_done_ts(adap
, status
, ktime_get());
279 void cec_received_msg_ts(struct cec_adapter
*adap
,
280 struct cec_msg
*msg
, ktime_t ts
);
282 static inline void cec_received_msg(struct cec_adapter
*adap
,
285 cec_received_msg_ts(adap
, msg
, ktime_get());
289 * cec_queue_pin_cec_event() - queue a CEC pin event with a given timestamp.
291 * @adap: pointer to the cec adapter
292 * @is_high: when true the CEC pin is high, otherwise it is low
293 * @dropped_events: when true some events were dropped
294 * @ts: the timestamp for this event
297 void cec_queue_pin_cec_event(struct cec_adapter
*adap
, bool is_high
,
298 bool dropped_events
, ktime_t ts
);
301 * cec_queue_pin_hpd_event() - queue a pin event with a given timestamp.
303 * @adap: pointer to the cec adapter
304 * @is_high: when true the HPD pin is high, otherwise it is low
305 * @ts: the timestamp for this event
308 void cec_queue_pin_hpd_event(struct cec_adapter
*adap
, bool is_high
, ktime_t ts
);
311 * cec_queue_pin_5v_event() - queue a pin event with a given timestamp.
313 * @adap: pointer to the cec adapter
314 * @is_high: when true the 5V pin is high, otherwise it is low
315 * @ts: the timestamp for this event
318 void cec_queue_pin_5v_event(struct cec_adapter
*adap
, bool is_high
, ktime_t ts
);
321 * cec_get_edid_phys_addr() - find and return the physical address
323 * @edid: pointer to the EDID data
324 * @size: size in bytes of the EDID data
325 * @offset: If not %NULL then the location of the physical address
326 * bytes in the EDID will be returned here. This is set to 0
327 * if there is no physical address found.
329 * Return: the physical address or CEC_PHYS_ADDR_INVALID if there is none.
331 u16
cec_get_edid_phys_addr(const u8
*edid
, unsigned int size
,
332 unsigned int *offset
);
336 static inline int cec_register_adapter(struct cec_adapter
*adap
,
337 struct device
*parent
)
342 static inline void cec_unregister_adapter(struct cec_adapter
*adap
)
346 static inline void cec_delete_adapter(struct cec_adapter
*adap
)
350 static inline void cec_s_phys_addr(struct cec_adapter
*adap
, u16 phys_addr
,
355 static inline void cec_s_phys_addr_from_edid(struct cec_adapter
*adap
,
356 const struct edid
*edid
)
360 static inline u16
cec_get_edid_phys_addr(const u8
*edid
, unsigned int size
,
361 unsigned int *offset
)
365 return CEC_PHYS_ADDR_INVALID
;
371 * cec_phys_addr_invalidate() - set the physical address to INVALID
373 * @adap: the CEC adapter
375 * This is a simple helper function to invalidate the physical
378 static inline void cec_phys_addr_invalidate(struct cec_adapter
*adap
)
380 cec_s_phys_addr(adap
, CEC_PHYS_ADDR_INVALID
, false);
384 * cec_get_edid_spa_location() - find location of the Source Physical Address
387 * @size: the size of the EDID
389 * This EDID is expected to be a CEA-861 compliant, which means that there are
390 * at least two blocks and one or more of the extensions blocks are CEA-861
393 * The returned location is guaranteed to be <= size-2.
395 * This is an inline function since it is used by both CEC and V4L2.
396 * Ideally this would go in a module shared by both, but it is overkill to do
397 * that for just a single function.
399 static inline unsigned int cec_get_edid_spa_location(const u8
*edid
,
402 unsigned int blocks
= size
/ 128;
406 /* Sanity check: at least 2 blocks and a multiple of the block size */
407 if (blocks
< 2 || size
% 128)
411 * If there are fewer extension blocks than the size, then update
412 * 'blocks'. It is allowed to have more extension blocks than the size,
413 * since some hardware can only read e.g. 256 bytes of the EDID, even
414 * though more blocks are present. The first CEA-861 extension block
415 * should normally be in block 1 anyway.
417 if (edid
[0x7e] + 1 < blocks
)
418 blocks
= edid
[0x7e] + 1;
420 for (block
= 1; block
< blocks
; block
++) {
421 unsigned int offset
= block
* 128;
423 /* Skip any non-CEA-861 extension blocks */
424 if (edid
[offset
] != 0x02 || edid
[offset
+ 1] != 0x03)
427 /* search Vendor Specific Data Block (tag 3) */
428 d
= edid
[offset
+ 2] & 0x7f;
429 /* Check if there are Data Blocks */
433 unsigned int i
= offset
+ 4;
434 unsigned int end
= offset
+ d
;
436 /* Note: 'end' is always < 'size' */
438 u8 tag
= edid
[i
] >> 5;
439 u8 len
= edid
[i
] & 0x1f;
441 if (tag
== 3 && len
>= 5 && i
+ len
<= end
&&
442 edid
[i
+ 1] == 0x03 &&
443 edid
[i
+ 2] == 0x0c &&
453 #endif /* _MEDIA_CEC_H */