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;
159 struct task_struct *kthread_config;
160 struct completion config_completion;
162 struct task_struct *kthread;
163 wait_queue_head_t kthread_waitq;
164 wait_queue_head_t waitq;
166 const struct cec_adap_ops *ops;
169 u8 available_log_addrs;
175 bool cec_pin_is_high;
180 struct cec_fh *cec_follower;
181 struct cec_fh *cec_initiator;
183 struct cec_log_addrs log_addrs;
187 #ifdef CONFIG_CEC_NOTIFIER
188 struct cec_notifier *notifier;
190 #ifdef CONFIG_CEC_PIN
194 struct dentry *cec_dir;
195 struct dentry *status_file;
196 struct dentry *error_inj_file;
204 static inline void *cec_get_drvdata(const struct cec_adapter *adap)
209 static inline bool cec_has_log_addr(const struct cec_adapter *adap, u8 log_addr)
211 return adap->log_addrs.log_addr_mask & (1 << log_addr);
214 static inline bool cec_is_sink(const struct cec_adapter *adap)
216 return adap->phys_addr == 0;
220 * cec_is_registered() - is the CEC adapter registered?
222 * @adap: the CEC adapter, may be NULL.
224 * Return: true if the adapter is registered, false otherwise.
226 static inline bool cec_is_registered(const struct cec_adapter *adap)
228 return adap && adap->devnode.registered;
231 #define cec_phys_addr_exp(pa) \
232 ((pa) >> 12), ((pa) >> 8) & 0xf, ((pa) >> 4) & 0xf, (pa) & 0xf
236 #if IS_REACHABLE(CONFIG_CEC_CORE)
237 struct cec_adapter *cec_allocate_adapter(const struct cec_adap_ops *ops,
238 void *priv, const char *name, u32 caps, u8 available_las);
239 int cec_register_adapter(struct cec_adapter *adap, struct device *parent);
240 void cec_unregister_adapter(struct cec_adapter *adap);
241 void cec_delete_adapter(struct cec_adapter *adap);
243 int cec_s_log_addrs(struct cec_adapter *adap, struct cec_log_addrs *log_addrs,
245 void cec_s_phys_addr(struct cec_adapter *adap, u16 phys_addr,
247 void cec_s_phys_addr_from_edid(struct cec_adapter *adap,
248 const struct edid *edid);
249 int cec_transmit_msg(struct cec_adapter *adap, struct cec_msg *msg,
252 /* Called by the adapter */
253 void cec_transmit_done_ts(struct cec_adapter *adap, u8 status,
254 u8 arb_lost_cnt, u8 nack_cnt, u8 low_drive_cnt,
255 u8 error_cnt, ktime_t ts);
257 static inline void cec_transmit_done(struct cec_adapter *adap, u8 status,
258 u8 arb_lost_cnt, u8 nack_cnt,
259 u8 low_drive_cnt, u8 error_cnt)
261 cec_transmit_done_ts(adap, status, arb_lost_cnt, nack_cnt,
262 low_drive_cnt, error_cnt, ktime_get());
265 * Simplified version of cec_transmit_done for hardware that doesn't retry
266 * failed transmits. So this is always just one attempt in which case
267 * the status is sufficient.
269 void cec_transmit_attempt_done_ts(struct cec_adapter *adap,
270 u8 status, ktime_t ts);
272 static inline void cec_transmit_attempt_done(struct cec_adapter *adap,
275 cec_transmit_attempt_done_ts(adap, status, ktime_get());
278 void cec_received_msg_ts(struct cec_adapter *adap,
279 struct cec_msg *msg, ktime_t ts);
281 static inline void cec_received_msg(struct cec_adapter *adap,
284 cec_received_msg_ts(adap, msg, ktime_get());
288 * cec_queue_pin_cec_event() - queue a CEC pin event with a given timestamp.
290 * @adap: pointer to the cec adapter
291 * @is_high: when true the CEC pin is high, otherwise it is low
292 * @dropped_events: when true some events were dropped
293 * @ts: the timestamp for this event
296 void cec_queue_pin_cec_event(struct cec_adapter *adap, bool is_high,
297 bool dropped_events, ktime_t ts);
300 * cec_queue_pin_hpd_event() - queue a pin event with a given timestamp.
302 * @adap: pointer to the cec adapter
303 * @is_high: when true the HPD pin is high, otherwise it is low
304 * @ts: the timestamp for this event
307 void cec_queue_pin_hpd_event(struct cec_adapter *adap, bool is_high, ktime_t ts);
310 * cec_queue_pin_5v_event() - queue a pin event with a given timestamp.
312 * @adap: pointer to the cec adapter
313 * @is_high: when true the 5V pin is high, otherwise it is low
314 * @ts: the timestamp for this event
317 void cec_queue_pin_5v_event(struct cec_adapter *adap, bool is_high, ktime_t ts);
320 * cec_get_edid_phys_addr() - find and return the physical address
322 * @edid: pointer to the EDID data
323 * @size: size in bytes of the EDID data
324 * @offset: If not %NULL then the location of the physical address
325 * bytes in the EDID will be returned here. This is set to 0
326 * if there is no physical address found.
328 * Return: the physical address or CEC_PHYS_ADDR_INVALID if there is none.
330 u16 cec_get_edid_phys_addr(const u8 *edid, unsigned int size,
331 unsigned int *offset);
335 static inline int cec_register_adapter(struct cec_adapter *adap,
336 struct device *parent)
341 static inline void cec_unregister_adapter(struct cec_adapter *adap)
345 static inline void cec_delete_adapter(struct cec_adapter *adap)
349 static inline void cec_s_phys_addr(struct cec_adapter *adap, u16 phys_addr,
354 static inline void cec_s_phys_addr_from_edid(struct cec_adapter *adap,
355 const struct edid *edid)
359 static inline u16 cec_get_edid_phys_addr(const u8 *edid, unsigned int size,
360 unsigned int *offset)
364 return CEC_PHYS_ADDR_INVALID;
370 * cec_phys_addr_invalidate() - set the physical address to INVALID
372 * @adap: the CEC adapter
374 * This is a simple helper function to invalidate the physical
377 static inline void cec_phys_addr_invalidate(struct cec_adapter *adap)
379 cec_s_phys_addr(adap, CEC_PHYS_ADDR_INVALID, false);
383 * cec_get_edid_spa_location() - find location of the Source Physical Address
386 * @size: the size of the EDID
388 * This EDID is expected to be a CEA-861 compliant, which means that there are
389 * at least two blocks and one or more of the extensions blocks are CEA-861
392 * The returned location is guaranteed to be <= size-2.
394 * This is an inline function since it is used by both CEC and V4L2.
395 * Ideally this would go in a module shared by both, but it is overkill to do
396 * that for just a single function.
398 static inline unsigned int cec_get_edid_spa_location(const u8 *edid,
401 unsigned int blocks = size / 128;
405 /* Sanity check: at least 2 blocks and a multiple of the block size */
406 if (blocks < 2 || size % 128)
410 * If there are fewer extension blocks than the size, then update
411 * 'blocks'. It is allowed to have more extension blocks than the size,
412 * since some hardware can only read e.g. 256 bytes of the EDID, even
413 * though more blocks are present. The first CEA-861 extension block
414 * should normally be in block 1 anyway.
416 if (edid[0x7e] + 1 < blocks)
417 blocks = edid[0x7e] + 1;
419 for (block = 1; block < blocks; block++) {
420 unsigned int offset = block * 128;
422 /* Skip any non-CEA-861 extension blocks */
423 if (edid[offset] != 0x02 || edid[offset + 1] != 0x03)
426 /* search Vendor Specific Data Block (tag 3) */
427 d = edid[offset + 2] & 0x7f;
428 /* Check if there are Data Blocks */
432 unsigned int i = offset + 4;
433 unsigned int end = offset + d;
435 /* Note: 'end' is always < 'size' */
437 u8 tag = edid[i] >> 5;
438 u8 len = edid[i] & 0x1f;
440 if (tag == 3 && len >= 5 && i + len <= end &&
441 edid[i + 1] == 0x03 &&
442 edid[i + 2] == 0x0c &&
452 #endif /* _MEDIA_CEC_H */