1 /* 2 * cec - HDMI Consumer Electronics Control support header 3 * 4 * Copyright 2016 Cisco Systems, Inc. and/or its affiliates. All rights reserved. 5 * 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. 9 * 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 17 * SOFTWARE. 18 */ 19 20 #ifndef _MEDIA_CEC_H 21 #define _MEDIA_CEC_H 22 23 #include <linux/poll.h> 24 #include <linux/fs.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> 33 34 /** 35 * struct cec_devnode - cec device node 36 * @dev: cec device 37 * @cdev: cec character device 38 * @minor: device node minor number 39 * @registered: the device was correctly registered 40 * @unregistered: the device was unregistered 41 * @fhs_lock: lock to control access to the filehandle list 42 * @fhs: the list of open filehandles (cec_fh) 43 * 44 * This structure represents a cec-related device node. 45 * 46 * The @parent is a physical device. It must be set by core or device drivers 47 * before registering the node. 48 */ 49 struct cec_devnode { 50 /* sysfs */ 51 struct device dev; 52 struct cdev cdev; 53 54 /* device info */ 55 int minor; 56 bool registered; 57 bool unregistered; 58 struct list_head fhs; 59 struct mutex lock; 60 }; 61 62 struct cec_adapter; 63 struct cec_data; 64 65 struct cec_data { 66 struct list_head list; 67 struct list_head xfer_list; 68 struct cec_adapter *adap; 69 struct cec_msg msg; 70 struct cec_fh *fh; 71 struct delayed_work work; 72 struct completion c; 73 u8 attempts; 74 bool new_initiator; 75 bool blocking; 76 bool completed; 77 }; 78 79 struct cec_msg_entry { 80 struct list_head list; 81 struct cec_msg msg; 82 }; 83 84 #define CEC_NUM_EVENTS CEC_EVENT_LOST_MSGS 85 86 struct cec_fh { 87 struct list_head list; 88 struct list_head xfer_list; 89 struct cec_adapter *adap; 90 u8 mode_initiator; 91 u8 mode_follower; 92 93 /* Events */ 94 wait_queue_head_t wait; 95 unsigned int pending_events; 96 struct cec_event events[CEC_NUM_EVENTS]; 97 struct mutex lock; 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) 108 109 struct 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_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); 117 118 /* High-level CEC message callback */ 119 int (*received)(struct cec_adapter *adap, struct cec_msg *msg); 120 }; 121 122 /* 123 * The minimum message length you can receive (excepting poll messages) is 2. 124 * With a transfer rate of at most 36 bytes per second this makes 18 messages 125 * per second worst case. 126 * 127 * We queue at most 3 seconds worth of received messages. The CEC specification 128 * requires that messages are replied to within a second, so 3 seconds should 129 * give more than enough margin. Since most messages are actually more than 2 130 * bytes, this is in practice a lot more than 3 seconds. 131 */ 132 #define CEC_MAX_MSG_RX_QUEUE_SZ (18 * 3) 133 134 /* 135 * The transmit queue is limited to 1 second worth of messages (worst case). 136 * Messages can be transmitted by userspace and kernel space. But for both it 137 * makes no sense to have a lot of messages queued up. One second seems 138 * reasonable. 139 */ 140 #define CEC_MAX_MSG_TX_QUEUE_SZ (18 * 1) 141 142 struct cec_adapter { 143 struct module *owner; 144 char name[32]; 145 struct cec_devnode devnode; 146 struct mutex lock; 147 struct rc_dev *rc; 148 149 struct list_head transmit_queue; 150 unsigned int transmit_queue_sz; 151 struct list_head wait_queue; 152 struct cec_data *transmitting; 153 154 struct task_struct *kthread_config; 155 struct completion config_completion; 156 157 struct task_struct *kthread; 158 wait_queue_head_t kthread_waitq; 159 wait_queue_head_t waitq; 160 161 const struct cec_adap_ops *ops; 162 void *priv; 163 u32 capabilities; 164 u8 available_log_addrs; 165 166 u16 phys_addr; 167 bool is_configuring; 168 bool is_configured; 169 u32 monitor_all_cnt; 170 u32 follower_cnt; 171 struct cec_fh *cec_follower; 172 struct cec_fh *cec_initiator; 173 bool passthrough; 174 struct cec_log_addrs log_addrs; 175 176 #ifdef CONFIG_CEC_NOTIFIER 177 struct cec_notifier *notifier; 178 #endif 179 180 struct dentry *cec_dir; 181 struct dentry *status_file; 182 183 u16 phys_addrs[15]; 184 u32 sequence; 185 186 char input_name[32]; 187 char input_phys[32]; 188 char input_drv[32]; 189 }; 190 191 static inline void *cec_get_drvdata(const struct cec_adapter *adap) 192 { 193 return adap->priv; 194 } 195 196 static inline bool cec_has_log_addr(const struct cec_adapter *adap, u8 log_addr) 197 { 198 return adap->log_addrs.log_addr_mask & (1 << log_addr); 199 } 200 201 static inline bool cec_is_sink(const struct cec_adapter *adap) 202 { 203 return adap->phys_addr == 0; 204 } 205 206 #define cec_phys_addr_exp(pa) \ 207 ((pa) >> 12), ((pa) >> 8) & 0xf, ((pa) >> 4) & 0xf, (pa) & 0xf 208 209 struct edid; 210 211 #if IS_ENABLED(CONFIG_CEC_CORE) 212 struct cec_adapter *cec_allocate_adapter(const struct cec_adap_ops *ops, 213 void *priv, const char *name, u32 caps, u8 available_las); 214 int cec_register_adapter(struct cec_adapter *adap, struct device *parent); 215 void cec_unregister_adapter(struct cec_adapter *adap); 216 void cec_delete_adapter(struct cec_adapter *adap); 217 218 int cec_s_log_addrs(struct cec_adapter *adap, struct cec_log_addrs *log_addrs, 219 bool block); 220 void cec_s_phys_addr(struct cec_adapter *adap, u16 phys_addr, 221 bool block); 222 void cec_s_phys_addr_from_edid(struct cec_adapter *adap, 223 const struct edid *edid); 224 int cec_transmit_msg(struct cec_adapter *adap, struct cec_msg *msg, 225 bool block); 226 227 /* Called by the adapter */ 228 void cec_transmit_done(struct cec_adapter *adap, u8 status, u8 arb_lost_cnt, 229 u8 nack_cnt, u8 low_drive_cnt, u8 error_cnt); 230 void cec_received_msg(struct cec_adapter *adap, struct cec_msg *msg); 231 232 /** 233 * cec_get_edid_phys_addr() - find and return the physical address 234 * 235 * @edid: pointer to the EDID data 236 * @size: size in bytes of the EDID data 237 * @offset: If not %NULL then the location of the physical address 238 * bytes in the EDID will be returned here. This is set to 0 239 * if there is no physical address found. 240 * 241 * Return: the physical address or CEC_PHYS_ADDR_INVALID if there is none. 242 */ 243 u16 cec_get_edid_phys_addr(const u8 *edid, unsigned int size, 244 unsigned int *offset); 245 246 /** 247 * cec_set_edid_phys_addr() - find and set the physical address 248 * 249 * @edid: pointer to the EDID data 250 * @size: size in bytes of the EDID data 251 * @phys_addr: the new physical address 252 * 253 * This function finds the location of the physical address in the EDID 254 * and fills in the given physical address and updates the checksum 255 * at the end of the EDID block. It does nothing if the EDID doesn't 256 * contain a physical address. 257 */ 258 void cec_set_edid_phys_addr(u8 *edid, unsigned int size, u16 phys_addr); 259 260 /** 261 * cec_phys_addr_for_input() - calculate the PA for an input 262 * 263 * @phys_addr: the physical address of the parent 264 * @input: the number of the input port, must be between 1 and 15 265 * 266 * This function calculates a new physical address based on the input 267 * port number. For example: 268 * 269 * PA = 0.0.0.0 and input = 2 becomes 2.0.0.0 270 * 271 * PA = 3.0.0.0 and input = 1 becomes 3.1.0.0 272 * 273 * PA = 3.2.1.0 and input = 5 becomes 3.2.1.5 274 * 275 * PA = 3.2.1.3 and input = 5 becomes f.f.f.f since it maxed out the depth. 276 * 277 * Return: the new physical address or CEC_PHYS_ADDR_INVALID. 278 */ 279 u16 cec_phys_addr_for_input(u16 phys_addr, u8 input); 280 281 /** 282 * cec_phys_addr_validate() - validate a physical address from an EDID 283 * 284 * @phys_addr: the physical address to validate 285 * @parent: if not %NULL, then this is filled with the parents PA. 286 * @port: if not %NULL, then this is filled with the input port. 287 * 288 * This validates a physical address as read from an EDID. If the 289 * PA is invalid (such as 1.0.1.0 since '0' is only allowed at the end), 290 * then it will return -EINVAL. 291 * 292 * The parent PA is passed into %parent and the input port is passed into 293 * %port. For example: 294 * 295 * PA = 0.0.0.0: has parent 0.0.0.0 and input port 0. 296 * 297 * PA = 1.0.0.0: has parent 0.0.0.0 and input port 1. 298 * 299 * PA = 3.2.0.0: has parent 3.0.0.0 and input port 2. 300 * 301 * PA = f.f.f.f: has parent f.f.f.f and input port 0. 302 * 303 * Return: 0 if the PA is valid, -EINVAL if not. 304 */ 305 int cec_phys_addr_validate(u16 phys_addr, u16 *parent, u16 *port); 306 307 #ifdef CONFIG_CEC_NOTIFIER 308 void cec_register_cec_notifier(struct cec_adapter *adap, 309 struct cec_notifier *notifier); 310 #endif 311 312 #else 313 314 static inline int cec_register_adapter(struct cec_adapter *adap, 315 struct device *parent) 316 { 317 return 0; 318 } 319 320 static inline void cec_unregister_adapter(struct cec_adapter *adap) 321 { 322 } 323 324 static inline void cec_delete_adapter(struct cec_adapter *adap) 325 { 326 } 327 328 static inline void cec_s_phys_addr(struct cec_adapter *adap, u16 phys_addr, 329 bool block) 330 { 331 } 332 333 static inline void cec_s_phys_addr_from_edid(struct cec_adapter *adap, 334 const struct edid *edid) 335 { 336 } 337 338 static inline u16 cec_get_edid_phys_addr(const u8 *edid, unsigned int size, 339 unsigned int *offset) 340 { 341 if (offset) 342 *offset = 0; 343 return CEC_PHYS_ADDR_INVALID; 344 } 345 346 static inline void cec_set_edid_phys_addr(u8 *edid, unsigned int size, 347 u16 phys_addr) 348 { 349 } 350 351 static inline u16 cec_phys_addr_for_input(u16 phys_addr, u8 input) 352 { 353 return CEC_PHYS_ADDR_INVALID; 354 } 355 356 static inline int cec_phys_addr_validate(u16 phys_addr, u16 *parent, u16 *port) 357 { 358 return 0; 359 } 360 361 #endif 362 363 /** 364 * cec_phys_addr_invalidate() - set the physical address to INVALID 365 * 366 * @adap: the CEC adapter 367 * 368 * This is a simple helper function to invalidate the physical 369 * address. 370 */ 371 static inline void cec_phys_addr_invalidate(struct cec_adapter *adap) 372 { 373 cec_s_phys_addr(adap, CEC_PHYS_ADDR_INVALID, false); 374 } 375 376 #endif /* _MEDIA_CEC_H */ 377