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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 */
40struct 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
53struct cec_adapter;
54struct cec_data;
55struct cec_pin;
56
57struct 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 new_initiator;
67 bool blocking;
68 bool completed;
69};
70
71struct cec_msg_entry {
72 struct list_head list;
73 struct cec_msg msg;
74};
75
76struct cec_event_entry {
77 struct list_head list;
78 struct cec_event ev;
79};
80
81#define CEC_NUM_CORE_EVENTS 2
82#define CEC_NUM_EVENTS CEC_EVENT_PIN_HPD_HIGH
83
84struct cec_fh {
85 struct list_head list;
86 struct list_head xfer_list;
87 struct cec_adapter *adap;
88 u8 mode_initiator;
89 u8 mode_follower;
90
91 /* Events */
92 wait_queue_head_t wait;
93 struct mutex lock;
94 struct list_head events[CEC_NUM_EVENTS]; /* queued events */
95 u16 queued_events[CEC_NUM_EVENTS];
96 unsigned int total_queued_events;
97 struct cec_event_entry core_events[CEC_NUM_CORE_EVENTS];
98 struct list_head msgs; /* queued messages */
99 unsigned int queued_msgs;
100};
101
102#define CEC_SIGNAL_FREE_TIME_RETRY 3
103#define CEC_SIGNAL_FREE_TIME_NEW_INITIATOR 5
104#define CEC_SIGNAL_FREE_TIME_NEXT_XFER 7
105
106/* The nominal data bit period is 2.4 ms */
107#define CEC_FREE_TIME_TO_USEC(ft) ((ft) * 2400)
108
109struct cec_adap_ops {
110 /* Low-level callbacks */
111 int (*adap_enable)(struct cec_adapter *adap, bool enable);
112 int (*adap_monitor_all_enable)(struct cec_adapter *adap, bool enable);
113 int (*adap_monitor_pin_enable)(struct cec_adapter *adap, bool enable);
114 int (*adap_log_addr)(struct cec_adapter *adap, u8 logical_addr);
115 int (*adap_transmit)(struct cec_adapter *adap, u8 attempts,
116 u32 signal_free_time, struct cec_msg *msg);
117 void (*adap_status)(struct cec_adapter *adap, struct seq_file *file);
118 void (*adap_free)(struct cec_adapter *adap);
119
120 /* Error injection callbacks */
121 int (*error_inj_show)(struct cec_adapter *adap, struct seq_file *sf);
122 bool (*error_inj_parse_line)(struct cec_adapter *adap, char *line);
123
124 /* High-level CEC message callback */
125 int (*received)(struct cec_adapter *adap, struct cec_msg *msg);
126};
127
128/*
129 * The minimum message length you can receive (excepting poll messages) is 2.
130 * With a transfer rate of at most 36 bytes per second this makes 18 messages
131 * per second worst case.
132 *
133 * We queue at most 3 seconds worth of received messages. The CEC specification
134 * requires that messages are replied to within a second, so 3 seconds should
135 * give more than enough margin. Since most messages are actually more than 2
136 * bytes, this is in practice a lot more than 3 seconds.
137 */
138#define CEC_MAX_MSG_RX_QUEUE_SZ (18 * 3)
139
140/*
141 * The transmit queue is limited to 1 second worth of messages (worst case).
142 * Messages can be transmitted by userspace and kernel space. But for both it
143 * makes no sense to have a lot of messages queued up. One second seems
144 * reasonable.
145 */
146#define CEC_MAX_MSG_TX_QUEUE_SZ (18 * 1)
147
148struct cec_adapter {
149 struct module *owner;
150 char name[32];
151 struct cec_devnode devnode;
152 struct mutex lock;
153 struct rc_dev *rc;
154
155 struct list_head transmit_queue;
156 unsigned int transmit_queue_sz;
157 struct list_head wait_queue;
158 struct cec_data *transmitting;
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 u32 monitor_all_cnt;
178 u32 monitor_pin_cnt;
179 u32 follower_cnt;
180 struct cec_fh *cec_follower;
181 struct cec_fh *cec_initiator;
182 bool passthrough;
183 struct cec_log_addrs log_addrs;
184
185 u32 tx_timeouts;
186
187#ifdef CONFIG_CEC_NOTIFIER
188 struct cec_notifier *notifier;
189#endif
190#ifdef CONFIG_CEC_PIN
191 struct cec_pin *pin;
192#endif
193
194 struct dentry *cec_dir;
195 struct dentry *status_file;
196 struct dentry *error_inj_file;
197
198 u16 phys_addrs[15];
199 u32 sequence;
200
201 char device_name[32];
202 char input_phys[32];
203 char input_drv[32];
204};
205
206static inline void *cec_get_drvdata(const struct cec_adapter *adap)
207{
208 return adap->priv;
209}
210
211static inline bool cec_has_log_addr(const struct cec_adapter *adap, u8 log_addr)
212{
213 return adap->log_addrs.log_addr_mask & (1 << log_addr);
214}
215
216static inline bool cec_is_sink(const struct cec_adapter *adap)
217{
218 return adap->phys_addr == 0;
219}
220
221/**
222 * cec_is_registered() - is the CEC adapter registered?
223 *
224 * @adap: the CEC adapter, may be NULL.
225 *
226 * Return: true if the adapter is registered, false otherwise.
227 */
228static inline bool cec_is_registered(const struct cec_adapter *adap)
229{
230 return adap && adap->devnode.registered;
231}
232
233#define cec_phys_addr_exp(pa) \
234 ((pa) >> 12), ((pa) >> 8) & 0xf, ((pa) >> 4) & 0xf, (pa) & 0xf
235
236struct edid;
237
238#if IS_REACHABLE(CONFIG_CEC_CORE)
239struct cec_adapter *cec_allocate_adapter(const struct cec_adap_ops *ops,
240 void *priv, const char *name, u32 caps, u8 available_las);
241int cec_register_adapter(struct cec_adapter *adap, struct device *parent);
242void cec_unregister_adapter(struct cec_adapter *adap);
243void cec_delete_adapter(struct cec_adapter *adap);
244
245int cec_s_log_addrs(struct cec_adapter *adap, struct cec_log_addrs *log_addrs,
246 bool block);
247void cec_s_phys_addr(struct cec_adapter *adap, u16 phys_addr,
248 bool block);
249void cec_s_phys_addr_from_edid(struct cec_adapter *adap,
250 const struct edid *edid);
251int cec_transmit_msg(struct cec_adapter *adap, struct cec_msg *msg,
252 bool block);
253
254/* Called by the adapter */
255void 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);
258
259static 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)
262{
263 cec_transmit_done_ts(adap, status, arb_lost_cnt, nack_cnt,
264 low_drive_cnt, error_cnt, ktime_get());
265}
266/*
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.
270 */
271void cec_transmit_attempt_done_ts(struct cec_adapter *adap,
272 u8 status, ktime_t ts);
273
274static inline void cec_transmit_attempt_done(struct cec_adapter *adap,
275 u8 status)
276{
277 cec_transmit_attempt_done_ts(adap, status, ktime_get());
278}
279
280void cec_received_msg_ts(struct cec_adapter *adap,
281 struct cec_msg *msg, ktime_t ts);
282
283static inline void cec_received_msg(struct cec_adapter *adap,
284 struct cec_msg *msg)
285{
286 cec_received_msg_ts(adap, msg, ktime_get());
287}
288
289/**
290 * cec_queue_pin_cec_event() - queue a CEC pin event with a given timestamp.
291 *
292 * @adap: pointer to the cec adapter
293 * @is_high: when true the CEC pin is high, otherwise it is low
294 * @dropped_events: when true some events were dropped
295 * @ts: the timestamp for this event
296 *
297 */
298void cec_queue_pin_cec_event(struct cec_adapter *adap, bool is_high,
299 bool dropped_events, ktime_t ts);
300
301/**
302 * cec_queue_pin_hpd_event() - queue a pin event with a given timestamp.
303 *
304 * @adap: pointer to the cec adapter
305 * @is_high: when true the HPD pin is high, otherwise it is low
306 * @ts: the timestamp for this event
307 *
308 */
309void cec_queue_pin_hpd_event(struct cec_adapter *adap, bool is_high, ktime_t ts);
310
311/**
312 * cec_get_edid_phys_addr() - find and return the physical address
313 *
314 * @edid: pointer to the EDID data
315 * @size: size in bytes of the EDID data
316 * @offset: If not %NULL then the location of the physical address
317 * bytes in the EDID will be returned here. This is set to 0
318 * if there is no physical address found.
319 *
320 * Return: the physical address or CEC_PHYS_ADDR_INVALID if there is none.
321 */
322u16 cec_get_edid_phys_addr(const u8 *edid, unsigned int size,
323 unsigned int *offset);
324
325/**
326 * cec_set_edid_phys_addr() - find and set the physical address
327 *
328 * @edid: pointer to the EDID data
329 * @size: size in bytes of the EDID data
330 * @phys_addr: the new physical address
331 *
332 * This function finds the location of the physical address in the EDID
333 * and fills in the given physical address and updates the checksum
334 * at the end of the EDID block. It does nothing if the EDID doesn't
335 * contain a physical address.
336 */
337void cec_set_edid_phys_addr(u8 *edid, unsigned int size, u16 phys_addr);
338
339/**
340 * cec_phys_addr_for_input() - calculate the PA for an input
341 *
342 * @phys_addr: the physical address of the parent
343 * @input: the number of the input port, must be between 1 and 15
344 *
345 * This function calculates a new physical address based on the input
346 * port number. For example:
347 *
348 * PA = 0.0.0.0 and input = 2 becomes 2.0.0.0
349 *
350 * PA = 3.0.0.0 and input = 1 becomes 3.1.0.0
351 *
352 * PA = 3.2.1.0 and input = 5 becomes 3.2.1.5
353 *
354 * PA = 3.2.1.3 and input = 5 becomes f.f.f.f since it maxed out the depth.
355 *
356 * Return: the new physical address or CEC_PHYS_ADDR_INVALID.
357 */
358u16 cec_phys_addr_for_input(u16 phys_addr, u8 input);
359
360/**
361 * cec_phys_addr_validate() - validate a physical address from an EDID
362 *
363 * @phys_addr: the physical address to validate
364 * @parent: if not %NULL, then this is filled with the parents PA.
365 * @port: if not %NULL, then this is filled with the input port.
366 *
367 * This validates a physical address as read from an EDID. If the
368 * PA is invalid (such as 1.0.1.0 since '0' is only allowed at the end),
369 * then it will return -EINVAL.
370 *
371 * The parent PA is passed into %parent and the input port is passed into
372 * %port. For example:
373 *
374 * PA = 0.0.0.0: has parent 0.0.0.0 and input port 0.
375 *
376 * PA = 1.0.0.0: has parent 0.0.0.0 and input port 1.
377 *
378 * PA = 3.2.0.0: has parent 3.0.0.0 and input port 2.
379 *
380 * PA = f.f.f.f: has parent f.f.f.f and input port 0.
381 *
382 * Return: 0 if the PA is valid, -EINVAL if not.
383 */
384int cec_phys_addr_validate(u16 phys_addr, u16 *parent, u16 *port);
385
386#else
387
388static inline int cec_register_adapter(struct cec_adapter *adap,
389 struct device *parent)
390{
391 return 0;
392}
393
394static inline void cec_unregister_adapter(struct cec_adapter *adap)
395{
396}
397
398static inline void cec_delete_adapter(struct cec_adapter *adap)
399{
400}
401
402static inline void cec_s_phys_addr(struct cec_adapter *adap, u16 phys_addr,
403 bool block)
404{
405}
406
407static inline void cec_s_phys_addr_from_edid(struct cec_adapter *adap,
408 const struct edid *edid)
409{
410}
411
412static inline u16 cec_get_edid_phys_addr(const u8 *edid, unsigned int size,
413 unsigned int *offset)
414{
415 if (offset)
416 *offset = 0;
417 return CEC_PHYS_ADDR_INVALID;
418}
419
420static inline void cec_set_edid_phys_addr(u8 *edid, unsigned int size,
421 u16 phys_addr)
422{
423}
424
425static inline u16 cec_phys_addr_for_input(u16 phys_addr, u8 input)
426{
427 return CEC_PHYS_ADDR_INVALID;
428}
429
430static inline int cec_phys_addr_validate(u16 phys_addr, u16 *parent, u16 *port)
431{
432 if (parent)
433 *parent = phys_addr;
434 if (port)
435 *port = 0;
436 return 0;
437}
438
439#endif
440
441/**
442 * cec_phys_addr_invalidate() - set the physical address to INVALID
443 *
444 * @adap: the CEC adapter
445 *
446 * This is a simple helper function to invalidate the physical
447 * address.
448 */
449static inline void cec_phys_addr_invalidate(struct cec_adapter *adap)
450{
451 cec_s_phys_addr(adap, CEC_PHYS_ADDR_INVALID, false);
452}
453
454#endif /* _MEDIA_CEC_H */