2 * cec - HDMI Consumer Electronics Control support header
4 * Copyright 2016 Cisco Systems, Inc. and/or its affiliates. All rights reserved.
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.
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
23 #include <linux/poll.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-notifier.h>
34 #define CEC_CAP_DEFAULTS (CEC_CAP_LOG_ADDRS | CEC_CAP_TRANSMIT | \
35 CEC_CAP_PASSTHROUGH | CEC_CAP_RC)
38 * struct cec_devnode - cec device node
40 * @cdev: cec character device
41 * @minor: device node minor number
42 * @registered: the device was correctly registered
43 * @unregistered: the device was unregistered
44 * @fhs_lock: lock to control access to the filehandle list
45 * @fhs: the list of open filehandles (cec_fh)
47 * This structure represents a cec-related device node.
49 * The @parent is a physical device. It must be set by core or device drivers
50 * before registering the node.
70 struct list_head list
;
71 struct list_head xfer_list
;
72 struct cec_adapter
*adap
;
75 struct delayed_work work
;
83 struct cec_msg_entry
{
84 struct list_head list
;
88 struct cec_event_entry
{
89 struct list_head list
;
93 #define CEC_NUM_CORE_EVENTS 2
94 #define CEC_NUM_EVENTS CEC_EVENT_PIN_HPD_HIGH
97 struct list_head list
;
98 struct list_head xfer_list
;
99 struct cec_adapter
*adap
;
104 wait_queue_head_t wait
;
106 struct list_head events
[CEC_NUM_EVENTS
]; /* queued events */
107 u8 queued_events
[CEC_NUM_EVENTS
];
108 unsigned int total_queued_events
;
109 struct cec_event_entry core_events
[CEC_NUM_CORE_EVENTS
];
110 struct list_head msgs
; /* queued messages */
111 unsigned int queued_msgs
;
114 #define CEC_SIGNAL_FREE_TIME_RETRY 3
115 #define CEC_SIGNAL_FREE_TIME_NEW_INITIATOR 5
116 #define CEC_SIGNAL_FREE_TIME_NEXT_XFER 7
118 /* The nominal data bit period is 2.4 ms */
119 #define CEC_FREE_TIME_TO_USEC(ft) ((ft) * 2400)
121 struct cec_adap_ops
{
122 /* Low-level callbacks */
123 int (*adap_enable
)(struct cec_adapter
*adap
, bool enable
);
124 int (*adap_monitor_all_enable
)(struct cec_adapter
*adap
, bool enable
);
125 int (*adap_log_addr
)(struct cec_adapter
*adap
, u8 logical_addr
);
126 int (*adap_transmit
)(struct cec_adapter
*adap
, u8 attempts
,
127 u32 signal_free_time
, struct cec_msg
*msg
);
128 void (*adap_status
)(struct cec_adapter
*adap
, struct seq_file
*file
);
129 void (*adap_free
)(struct cec_adapter
*adap
);
131 /* High-level CEC message callback */
132 int (*received
)(struct cec_adapter
*adap
, struct cec_msg
*msg
);
136 * The minimum message length you can receive (excepting poll messages) is 2.
137 * With a transfer rate of at most 36 bytes per second this makes 18 messages
138 * per second worst case.
140 * We queue at most 3 seconds worth of received messages. The CEC specification
141 * requires that messages are replied to within a second, so 3 seconds should
142 * give more than enough margin. Since most messages are actually more than 2
143 * bytes, this is in practice a lot more than 3 seconds.
145 #define CEC_MAX_MSG_RX_QUEUE_SZ (18 * 3)
148 * The transmit queue is limited to 1 second worth of messages (worst case).
149 * Messages can be transmitted by userspace and kernel space. But for both it
150 * makes no sense to have a lot of messages queued up. One second seems
153 #define CEC_MAX_MSG_TX_QUEUE_SZ (18 * 1)
156 struct module
*owner
;
158 struct cec_devnode devnode
;
162 struct list_head transmit_queue
;
163 unsigned int transmit_queue_sz
;
164 struct list_head wait_queue
;
165 struct cec_data
*transmitting
;
166 bool transmit_in_progress
;
168 struct task_struct
*kthread_config
;
169 struct completion config_completion
;
171 struct task_struct
*kthread
;
172 wait_queue_head_t kthread_waitq
;
173 wait_queue_head_t waitq
;
175 const struct cec_adap_ops
*ops
;
178 u8 available_log_addrs
;
184 bool cec_pin_is_high
;
188 struct cec_fh
*cec_follower
;
189 struct cec_fh
*cec_initiator
;
191 struct cec_log_addrs log_addrs
;
195 #ifdef CONFIG_MEDIA_CEC_RC
197 int rc_last_scancode
;
198 u64 rc_last_keypress
;
200 #ifdef CONFIG_CEC_NOTIFIER
201 struct cec_notifier
*notifier
;
203 #ifdef CONFIG_CEC_PIN
207 struct dentry
*cec_dir
;
208 struct dentry
*status_file
;
213 char device_name
[32];
218 static inline void *cec_get_drvdata(const struct cec_adapter
*adap
)
223 static inline bool cec_has_log_addr(const struct cec_adapter
*adap
, u8 log_addr
)
225 return adap
->log_addrs
.log_addr_mask
& (1 << log_addr
);
228 static inline bool cec_is_sink(const struct cec_adapter
*adap
)
230 return adap
->phys_addr
== 0;
233 #define cec_phys_addr_exp(pa) \
234 ((pa) >> 12), ((pa) >> 8) & 0xf, ((pa) >> 4) & 0xf, (pa) & 0xf
238 #if IS_REACHABLE(CONFIG_CEC_CORE)
239 struct cec_adapter
*cec_allocate_adapter(const struct cec_adap_ops
*ops
,
240 void *priv
, const char *name
, u32 caps
, u8 available_las
);
241 int cec_register_adapter(struct cec_adapter
*adap
, struct device
*parent
);
242 void cec_unregister_adapter(struct cec_adapter
*adap
);
243 void cec_delete_adapter(struct cec_adapter
*adap
);
245 int cec_s_log_addrs(struct cec_adapter
*adap
, struct cec_log_addrs
*log_addrs
,
247 void cec_s_phys_addr(struct cec_adapter
*adap
, u16 phys_addr
,
249 void cec_s_phys_addr_from_edid(struct cec_adapter
*adap
,
250 const struct edid
*edid
);
251 int cec_transmit_msg(struct cec_adapter
*adap
, struct cec_msg
*msg
,
254 /* Called by the adapter */
255 void cec_transmit_done_ts(struct cec_adapter
*adap
, u8 status
,
256 u8 arb_lost_cnt
, u8 nack_cnt
, u8 low_drive_cnt
,
257 u8 error_cnt
, ktime_t ts
);
259 static inline void cec_transmit_done(struct cec_adapter
*adap
, u8 status
,
260 u8 arb_lost_cnt
, u8 nack_cnt
,
261 u8 low_drive_cnt
, u8 error_cnt
)
263 cec_transmit_done_ts(adap
, status
, arb_lost_cnt
, nack_cnt
,
264 low_drive_cnt
, error_cnt
, ktime_get());
267 * Simplified version of cec_transmit_done for hardware that doesn't retry
268 * failed transmits. So this is always just one attempt in which case
269 * the status is sufficient.
271 void cec_transmit_attempt_done_ts(struct cec_adapter
*adap
,
272 u8 status
, ktime_t ts
);
274 static inline void cec_transmit_attempt_done(struct cec_adapter
*adap
,
277 cec_transmit_attempt_done_ts(adap
, status
, ktime_get());
280 void cec_received_msg_ts(struct cec_adapter
*adap
,
281 struct cec_msg
*msg
, ktime_t ts
);
283 static inline void cec_received_msg(struct cec_adapter
*adap
,
286 cec_received_msg_ts(adap
, msg
, ktime_get());
290 * cec_queue_pin_cec_event() - queue a CEC pin event with a given timestamp.
292 * @adap: pointer to the cec adapter
293 * @is_high: when true the CEC pin is high, otherwise it is low
294 * @ts: the timestamp for this event
297 void cec_queue_pin_cec_event(struct cec_adapter
*adap
,
298 bool is_high
, 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_get_edid_phys_addr() - find and return the physical address
313 * @edid: pointer to the EDID data
314 * @size: size in bytes of the EDID data
315 * @offset: If not %NULL then the location of the physical address
316 * bytes in the EDID will be returned here. This is set to 0
317 * if there is no physical address found.
319 * Return: the physical address or CEC_PHYS_ADDR_INVALID if there is none.
321 u16
cec_get_edid_phys_addr(const u8
*edid
, unsigned int size
,
322 unsigned int *offset
);
325 * cec_set_edid_phys_addr() - find and set the physical address
327 * @edid: pointer to the EDID data
328 * @size: size in bytes of the EDID data
329 * @phys_addr: the new physical address
331 * This function finds the location of the physical address in the EDID
332 * and fills in the given physical address and updates the checksum
333 * at the end of the EDID block. It does nothing if the EDID doesn't
334 * contain a physical address.
336 void cec_set_edid_phys_addr(u8
*edid
, unsigned int size
, u16 phys_addr
);
339 * cec_phys_addr_for_input() - calculate the PA for an input
341 * @phys_addr: the physical address of the parent
342 * @input: the number of the input port, must be between 1 and 15
344 * This function calculates a new physical address based on the input
345 * port number. For example:
347 * PA = 0.0.0.0 and input = 2 becomes 2.0.0.0
349 * PA = 3.0.0.0 and input = 1 becomes 3.1.0.0
351 * PA = 3.2.1.0 and input = 5 becomes 3.2.1.5
353 * PA = 3.2.1.3 and input = 5 becomes f.f.f.f since it maxed out the depth.
355 * Return: the new physical address or CEC_PHYS_ADDR_INVALID.
357 u16
cec_phys_addr_for_input(u16 phys_addr
, u8 input
);
360 * cec_phys_addr_validate() - validate a physical address from an EDID
362 * @phys_addr: the physical address to validate
363 * @parent: if not %NULL, then this is filled with the parents PA.
364 * @port: if not %NULL, then this is filled with the input port.
366 * This validates a physical address as read from an EDID. If the
367 * PA is invalid (such as 1.0.1.0 since '0' is only allowed at the end),
368 * then it will return -EINVAL.
370 * The parent PA is passed into %parent and the input port is passed into
371 * %port. For example:
373 * PA = 0.0.0.0: has parent 0.0.0.0 and input port 0.
375 * PA = 1.0.0.0: has parent 0.0.0.0 and input port 1.
377 * PA = 3.2.0.0: has parent 3.0.0.0 and input port 2.
379 * PA = f.f.f.f: has parent f.f.f.f and input port 0.
381 * Return: 0 if the PA is valid, -EINVAL if not.
383 int cec_phys_addr_validate(u16 phys_addr
, u16
*parent
, u16
*port
);
387 static inline int cec_register_adapter(struct cec_adapter
*adap
,
388 struct device
*parent
)
393 static inline void cec_unregister_adapter(struct cec_adapter
*adap
)
397 static inline void cec_delete_adapter(struct cec_adapter
*adap
)
401 static inline void cec_s_phys_addr(struct cec_adapter
*adap
, u16 phys_addr
,
406 static inline void cec_s_phys_addr_from_edid(struct cec_adapter
*adap
,
407 const struct edid
*edid
)
411 static inline u16
cec_get_edid_phys_addr(const u8
*edid
, unsigned int size
,
412 unsigned int *offset
)
416 return CEC_PHYS_ADDR_INVALID
;
419 static inline void cec_set_edid_phys_addr(u8
*edid
, unsigned int size
,
424 static inline u16
cec_phys_addr_for_input(u16 phys_addr
, u8 input
)
426 return CEC_PHYS_ADDR_INVALID
;
429 static inline int cec_phys_addr_validate(u16 phys_addr
, u16
*parent
, u16
*port
)
441 * cec_phys_addr_invalidate() - set the physical address to INVALID
443 * @adap: the CEC adapter
445 * This is a simple helper function to invalidate the physical
448 static inline void cec_phys_addr_invalidate(struct cec_adapter
*adap
)
450 cec_s_phys_addr(adap
, CEC_PHYS_ADDR_INVALID
, false);
454 * cec_get_edid_spa_location() - find location of the Source Physical Address
457 * @size: the size of the EDID
459 * This EDID is expected to be a CEA-861 compliant, which means that there are
460 * at least two blocks and one or more of the extensions blocks are CEA-861
463 * The returned location is guaranteed to be <= size-2.
465 * This is an inline function since it is used by both CEC and V4L2.
466 * Ideally this would go in a module shared by both, but it is overkill to do
467 * that for just a single function.
469 static inline unsigned int cec_get_edid_spa_location(const u8
*edid
,
472 unsigned int blocks
= size
/ 128;
476 /* Sanity check: at least 2 blocks and a multiple of the block size */
477 if (blocks
< 2 || size
% 128)
481 * If there are fewer extension blocks than the size, then update
482 * 'blocks'. It is allowed to have more extension blocks than the size,
483 * since some hardware can only read e.g. 256 bytes of the EDID, even
484 * though more blocks are present. The first CEA-861 extension block
485 * should normally be in block 1 anyway.
487 if (edid
[0x7e] + 1 < blocks
)
488 blocks
= edid
[0x7e] + 1;
490 for (block
= 1; block
< blocks
; block
++) {
491 unsigned int offset
= block
* 128;
493 /* Skip any non-CEA-861 extension blocks */
494 if (edid
[offset
] != 0x02 || edid
[offset
+ 1] != 0x03)
497 /* search Vendor Specific Data Block (tag 3) */
498 d
= edid
[offset
+ 2] & 0x7f;
499 /* Check if there are Data Blocks */
503 unsigned int i
= offset
+ 4;
504 unsigned int end
= offset
+ d
;
506 /* Note: 'end' is always < 'size' */
508 u8 tag
= edid
[i
] >> 5;
509 u8 len
= edid
[i
] & 0x1f;
511 if (tag
== 3 && len
>= 5 && i
+ len
<= end
&&
512 edid
[i
+ 1] == 0x03 &&
513 edid
[i
+ 2] == 0x0c &&
523 #endif /* _MEDIA_CEC_H */