1 /* SPDX-License-Identifier: GPL-2.0-only */
2 /*
3 * cec - HDMI Consumer Electronics Control support header
4 *
5 * Copyright 2016 Cisco Systems, Inc. and/or its affiliates. All rights reserved.
6 */
7
8 #ifndef _MEDIA_CEC_H
9 #define _MEDIA_CEC_H
10
11 #include <linux/poll.h>
12 #include <linux/fs.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>
21
22 #define CEC_CAP_DEFAULTS (CEC_CAP_LOG_ADDRS | CEC_CAP_TRANSMIT | \
23 CEC_CAP_PASSTHROUGH | CEC_CAP_RC)
24
25 /**
26 * struct cec_devnode - cec device node
27 * @dev: cec device
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)
34 *
35 * This structure represents a cec-related device node.
36 *
37 * The @parent is a physical device. It must be set by core or device drivers
38 * before registering the node.
39 */
40 struct cec_devnode {
41 /* sysfs */
42 struct device dev;
43 struct cdev cdev;
44
45 /* device info */
46 int minor;
47 bool registered;
48 bool unregistered;
49 struct list_head fhs;
50 struct mutex lock;
51 };
52
53 struct cec_adapter;
54 struct cec_data;
55 struct cec_pin;
56
57 struct cec_data {
58 struct list_head list;
59 struct list_head xfer_list;
60 struct cec_adapter *adap;
61 struct cec_msg msg;
62 struct cec_fh *fh;
63 struct delayed_work work;
64 struct completion c;
65 u8 attempts;
66 bool blocking;
67 bool completed;
68 };
69
70 struct cec_msg_entry {
71 struct list_head list;
72 struct cec_msg msg;
73 };
74
75 struct cec_event_entry {
76 struct list_head list;
77 struct cec_event ev;
78 };
79
80 #define CEC_NUM_CORE_EVENTS 2
81 #define CEC_NUM_EVENTS CEC_EVENT_PIN_5V_HIGH
82
83 struct cec_fh {
84 struct list_head list;
85 struct list_head xfer_list;
86 struct cec_adapter *adap;
87 u8 mode_initiator;
88 u8 mode_follower;
89
90 /* Events */
91 wait_queue_head_t wait;
92 struct mutex lock;
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;
99 };
100
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
104
105 /* The nominal data bit period is 2.4 ms */
106 #define CEC_FREE_TIME_TO_USEC(ft) ((ft) * 2400)
107
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);
118
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);
122
123 /* High-level CEC message callback */
124 int (*received)(struct cec_adapter *adap, struct cec_msg *msg);
125 };
126
127 /*
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.
131 *
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.
136 */
137 #define CEC_MAX_MSG_RX_QUEUE_SZ (18 * 3)
138
139 /*
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
143 * reasonable.
144 */
145 #define CEC_MAX_MSG_TX_QUEUE_SZ (18 * 1)
146
147 struct cec_adapter {
148 struct module *owner;
149 char name[32];
150 struct cec_devnode devnode;
151 struct mutex lock;
152 struct rc_dev *rc;
153
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;
159
160 struct task_struct *kthread_config;
161 struct completion config_completion;
162
163 struct task_struct *kthread;
164 wait_queue_head_t kthread_waitq;
165 wait_queue_head_t waitq;
166
167 const struct cec_adap_ops *ops;
168 void *priv;
169 u32 capabilities;
170 u8 available_log_addrs;
171
172 u16 phys_addr;
173 bool needs_hpd;
174 bool is_configuring;
175 bool is_configured;
176 bool cec_pin_is_high;
177 u8 last_initiator;
178 u32 monitor_all_cnt;
179 u32 monitor_pin_cnt;
180 u32 follower_cnt;
181 struct cec_fh *cec_follower;
182 struct cec_fh *cec_initiator;
183 bool passthrough;
184 struct cec_log_addrs log_addrs;
185
186 u32 tx_timeouts;
187
188 #ifdef CONFIG_CEC_NOTIFIER
189 struct cec_notifier *notifier;
190 #endif
191 #ifdef CONFIG_CEC_PIN
192 struct cec_pin *pin;
193 #endif
194
195 struct dentry *cec_dir;
196 struct dentry *status_file;
197 struct dentry *error_inj_file;
198
199 u16 phys_addrs[15];
200 u32 sequence;
201
202 char device_name[32];
203 char input_phys[32];
204 char input_drv[32];
205 };
206
cec_get_drvdata(const struct cec_adapter * adap)207 static inline void *cec_get_drvdata(const struct cec_adapter *adap)
208 {
209 return adap->priv;
210 }
211
cec_has_log_addr(const struct cec_adapter * adap,u8 log_addr)212 static inline bool cec_has_log_addr(const struct cec_adapter *adap, u8 log_addr)
213 {
214 return adap->log_addrs.log_addr_mask & (1 << log_addr);
215 }
216
cec_is_sink(const struct cec_adapter * adap)217 static inline bool cec_is_sink(const struct cec_adapter *adap)
218 {
219 return adap->phys_addr == 0;
220 }
221
222 /**
223 * cec_is_registered() - is the CEC adapter registered?
224 *
225 * @adap: the CEC adapter, may be NULL.
226 *
227 * Return: true if the adapter is registered, false otherwise.
228 */
cec_is_registered(const struct cec_adapter * adap)229 static inline bool cec_is_registered(const struct cec_adapter *adap)
230 {
231 return adap && adap->devnode.registered;
232 }
233
234 #define cec_phys_addr_exp(pa) \
235 ((pa) >> 12), ((pa) >> 8) & 0xf, ((pa) >> 4) & 0xf, (pa) & 0xf
236
237 struct edid;
238
239 #if IS_REACHABLE(CONFIG_CEC_CORE)
240 struct cec_adapter *cec_allocate_adapter(const struct cec_adap_ops *ops,
241 void *priv, const char *name, u32 caps, u8 available_las);
242 int cec_register_adapter(struct cec_adapter *adap, struct device *parent);
243 void cec_unregister_adapter(struct cec_adapter *adap);
244 void cec_delete_adapter(struct cec_adapter *adap);
245
246 int cec_s_log_addrs(struct cec_adapter *adap, struct cec_log_addrs *log_addrs,
247 bool block);
248 void cec_s_phys_addr(struct cec_adapter *adap, u16 phys_addr,
249 bool block);
250 void cec_s_phys_addr_from_edid(struct cec_adapter *adap,
251 const struct edid *edid);
252 int cec_transmit_msg(struct cec_adapter *adap, struct cec_msg *msg,
253 bool block);
254
255 /* Called by the adapter */
256 void cec_transmit_done_ts(struct cec_adapter *adap, u8 status,
257 u8 arb_lost_cnt, u8 nack_cnt, u8 low_drive_cnt,
258 u8 error_cnt, ktime_t ts);
259
cec_transmit_done(struct cec_adapter * adap,u8 status,u8 arb_lost_cnt,u8 nack_cnt,u8 low_drive_cnt,u8 error_cnt)260 static inline void cec_transmit_done(struct cec_adapter *adap, u8 status,
261 u8 arb_lost_cnt, u8 nack_cnt,
262 u8 low_drive_cnt, u8 error_cnt)
263 {
264 cec_transmit_done_ts(adap, status, arb_lost_cnt, nack_cnt,
265 low_drive_cnt, error_cnt, ktime_get());
266 }
267 /*
268 * Simplified version of cec_transmit_done for hardware that doesn't retry
269 * failed transmits. So this is always just one attempt in which case
270 * the status is sufficient.
271 */
272 void cec_transmit_attempt_done_ts(struct cec_adapter *adap,
273 u8 status, ktime_t ts);
274
cec_transmit_attempt_done(struct cec_adapter * adap,u8 status)275 static inline void cec_transmit_attempt_done(struct cec_adapter *adap,
276 u8 status)
277 {
278 cec_transmit_attempt_done_ts(adap, status, ktime_get());
279 }
280
281 void cec_received_msg_ts(struct cec_adapter *adap,
282 struct cec_msg *msg, ktime_t ts);
283
cec_received_msg(struct cec_adapter * adap,struct cec_msg * msg)284 static inline void cec_received_msg(struct cec_adapter *adap,
285 struct cec_msg *msg)
286 {
287 cec_received_msg_ts(adap, msg, ktime_get());
288 }
289
290 /**
291 * cec_queue_pin_cec_event() - queue a CEC pin event with a given timestamp.
292 *
293 * @adap: pointer to the cec adapter
294 * @is_high: when true the CEC pin is high, otherwise it is low
295 * @dropped_events: when true some events were dropped
296 * @ts: the timestamp for this event
297 *
298 */
299 void cec_queue_pin_cec_event(struct cec_adapter *adap, bool is_high,
300 bool dropped_events, ktime_t ts);
301
302 /**
303 * cec_queue_pin_hpd_event() - queue a pin event with a given timestamp.
304 *
305 * @adap: pointer to the cec adapter
306 * @is_high: when true the HPD pin is high, otherwise it is low
307 * @ts: the timestamp for this event
308 *
309 */
310 void cec_queue_pin_hpd_event(struct cec_adapter *adap, bool is_high, ktime_t ts);
311
312 /**
313 * cec_queue_pin_5v_event() - queue a pin event with a given timestamp.
314 *
315 * @adap: pointer to the cec adapter
316 * @is_high: when true the 5V pin is high, otherwise it is low
317 * @ts: the timestamp for this event
318 *
319 */
320 void cec_queue_pin_5v_event(struct cec_adapter *adap, bool is_high, ktime_t ts);
321
322 /**
323 * cec_get_edid_phys_addr() - find and return the physical address
324 *
325 * @edid: pointer to the EDID data
326 * @size: size in bytes of the EDID data
327 * @offset: If not %NULL then the location of the physical address
328 * bytes in the EDID will be returned here. This is set to 0
329 * if there is no physical address found.
330 *
331 * Return: the physical address or CEC_PHYS_ADDR_INVALID if there is none.
332 */
333 u16 cec_get_edid_phys_addr(const u8 *edid, unsigned int size,
334 unsigned int *offset);
335
336 #else
337
cec_register_adapter(struct cec_adapter * adap,struct device * parent)338 static inline int cec_register_adapter(struct cec_adapter *adap,
339 struct device *parent)
340 {
341 return 0;
342 }
343
cec_unregister_adapter(struct cec_adapter * adap)344 static inline void cec_unregister_adapter(struct cec_adapter *adap)
345 {
346 }
347
cec_delete_adapter(struct cec_adapter * adap)348 static inline void cec_delete_adapter(struct cec_adapter *adap)
349 {
350 }
351
cec_s_phys_addr(struct cec_adapter * adap,u16 phys_addr,bool block)352 static inline void cec_s_phys_addr(struct cec_adapter *adap, u16 phys_addr,
353 bool block)
354 {
355 }
356
cec_s_phys_addr_from_edid(struct cec_adapter * adap,const struct edid * edid)357 static inline void cec_s_phys_addr_from_edid(struct cec_adapter *adap,
358 const struct edid *edid)
359 {
360 }
361
cec_get_edid_phys_addr(const u8 * edid,unsigned int size,unsigned int * offset)362 static inline u16 cec_get_edid_phys_addr(const u8 *edid, unsigned int size,
363 unsigned int *offset)
364 {
365 if (offset)
366 *offset = 0;
367 return CEC_PHYS_ADDR_INVALID;
368 }
369
370 #endif
371
372 /**
373 * cec_phys_addr_invalidate() - set the physical address to INVALID
374 *
375 * @adap: the CEC adapter
376 *
377 * This is a simple helper function to invalidate the physical
378 * address.
379 */
cec_phys_addr_invalidate(struct cec_adapter * adap)380 static inline void cec_phys_addr_invalidate(struct cec_adapter *adap)
381 {
382 cec_s_phys_addr(adap, CEC_PHYS_ADDR_INVALID, false);
383 }
384
385 /**
386 * cec_get_edid_spa_location() - find location of the Source Physical Address
387 *
388 * @edid: the EDID
389 * @size: the size of the EDID
390 *
391 * This EDID is expected to be a CEA-861 compliant, which means that there are
392 * at least two blocks and one or more of the extensions blocks are CEA-861
393 * blocks.
394 *
395 * The returned location is guaranteed to be <= size-2.
396 *
397 * This is an inline function since it is used by both CEC and V4L2.
398 * Ideally this would go in a module shared by both, but it is overkill to do
399 * that for just a single function.
400 */
cec_get_edid_spa_location(const u8 * edid,unsigned int size)401 static inline unsigned int cec_get_edid_spa_location(const u8 *edid,
402 unsigned int size)
403 {
404 unsigned int blocks = size / 128;
405 unsigned int block;
406 u8 d;
407
408 /* Sanity check: at least 2 blocks and a multiple of the block size */
409 if (blocks < 2 || size % 128)
410 return 0;
411
412 /*
413 * If there are fewer extension blocks than the size, then update
414 * 'blocks'. It is allowed to have more extension blocks than the size,
415 * since some hardware can only read e.g. 256 bytes of the EDID, even
416 * though more blocks are present. The first CEA-861 extension block
417 * should normally be in block 1 anyway.
418 */
419 if (edid[0x7e] + 1 < blocks)
420 blocks = edid[0x7e] + 1;
421
422 for (block = 1; block < blocks; block++) {
423 unsigned int offset = block * 128;
424
425 /* Skip any non-CEA-861 extension blocks */
426 if (edid[offset] != 0x02 || edid[offset + 1] != 0x03)
427 continue;
428
429 /* search Vendor Specific Data Block (tag 3) */
430 d = edid[offset + 2] & 0x7f;
431 /* Check if there are Data Blocks */
432 if (d <= 4)
433 continue;
434 if (d > 4) {
435 unsigned int i = offset + 4;
436 unsigned int end = offset + d;
437
438 /* Note: 'end' is always < 'size' */
439 do {
440 u8 tag = edid[i] >> 5;
441 u8 len = edid[i] & 0x1f;
442
443 if (tag == 3 && len >= 5 && i + len <= end &&
444 edid[i + 1] == 0x03 &&
445 edid[i + 2] == 0x0c &&
446 edid[i + 3] == 0x00)
447 return i + 4;
448 i += len + 1;
449 } while (i < end);
450 }
451 }
452 return 0;
453 }
454
455 #endif /* _MEDIA_CEC_H */
456