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-edid.h> 33 34 /** 35 * struct cec_devnode - cec device node 36 * @dev: cec device 37 * @cdev: cec character device 38 * @parent: parent device 39 * @minor: device node minor number 40 * @registered: the device was correctly registered 41 * @unregistered: the device was unregistered 42 * @fhs_lock: lock to control access to the filehandle list 43 * @fhs: the list of open filehandles (cec_fh) 44 * 45 * This structure represents a cec-related device node. 46 * 47 * The @parent is a physical device. It must be set by core or device drivers 48 * before registering the node. 49 */ 50 struct cec_devnode { 51 /* sysfs */ 52 struct device dev; 53 struct cdev cdev; 54 struct device *parent; 55 56 /* device info */ 57 int minor; 58 bool registered; 59 bool unregistered; 60 struct list_head fhs; 61 struct mutex lock; 62 }; 63 64 struct cec_adapter; 65 struct cec_data; 66 67 struct cec_data { 68 struct list_head list; 69 struct list_head xfer_list; 70 struct cec_adapter *adap; 71 struct cec_msg msg; 72 struct cec_fh *fh; 73 struct delayed_work work; 74 struct completion c; 75 u8 attempts; 76 bool new_initiator; 77 bool blocking; 78 bool completed; 79 }; 80 81 struct cec_msg_entry { 82 struct list_head list; 83 struct cec_msg msg; 84 }; 85 86 #define CEC_NUM_EVENTS CEC_EVENT_LOST_MSGS 87 88 struct cec_fh { 89 struct list_head list; 90 struct list_head xfer_list; 91 struct cec_adapter *adap; 92 u8 mode_initiator; 93 u8 mode_follower; 94 95 /* Events */ 96 wait_queue_head_t wait; 97 unsigned int pending_events; 98 struct cec_event events[CEC_NUM_EVENTS]; 99 struct mutex lock; 100 struct list_head msgs; /* queued messages */ 101 unsigned int queued_msgs; 102 }; 103 104 #define CEC_SIGNAL_FREE_TIME_RETRY 3 105 #define CEC_SIGNAL_FREE_TIME_NEW_INITIATOR 5 106 #define CEC_SIGNAL_FREE_TIME_NEXT_XFER 7 107 108 /* The nominal data bit period is 2.4 ms */ 109 #define CEC_FREE_TIME_TO_USEC(ft) ((ft) * 2400) 110 111 struct cec_adap_ops { 112 /* Low-level callbacks */ 113 int (*adap_enable)(struct cec_adapter *adap, bool enable); 114 int (*adap_monitor_all_enable)(struct cec_adapter *adap, bool enable); 115 int (*adap_log_addr)(struct cec_adapter *adap, u8 logical_addr); 116 int (*adap_transmit)(struct cec_adapter *adap, u8 attempts, 117 u32 signal_free_time, struct cec_msg *msg); 118 void (*adap_status)(struct cec_adapter *adap, struct seq_file *file); 119 120 /* High-level CEC message callback */ 121 int (*received)(struct cec_adapter *adap, struct cec_msg *msg); 122 }; 123 124 /* 125 * The minimum message length you can receive (excepting poll messages) is 2. 126 * With a transfer rate of at most 36 bytes per second this makes 18 messages 127 * per second worst case. 128 * 129 * We queue at most 3 seconds worth of received messages. The CEC specification 130 * requires that messages are replied to within a second, so 3 seconds should 131 * give more than enough margin. Since most messages are actually more than 2 132 * bytes, this is in practice a lot more than 3 seconds. 133 */ 134 #define CEC_MAX_MSG_RX_QUEUE_SZ (18 * 3) 135 136 /* 137 * The transmit queue is limited to 1 second worth of messages (worst case). 138 * Messages can be transmitted by userspace and kernel space. But for both it 139 * makes no sense to have a lot of messages queued up. One second seems 140 * reasonable. 141 */ 142 #define CEC_MAX_MSG_TX_QUEUE_SZ (18 * 1) 143 144 struct cec_adapter { 145 struct module *owner; 146 char name[32]; 147 struct cec_devnode devnode; 148 struct mutex lock; 149 struct rc_dev *rc; 150 151 struct list_head transmit_queue; 152 unsigned int transmit_queue_sz; 153 struct list_head wait_queue; 154 struct cec_data *transmitting; 155 156 struct task_struct *kthread_config; 157 struct completion config_completion; 158 159 struct task_struct *kthread; 160 wait_queue_head_t kthread_waitq; 161 wait_queue_head_t waitq; 162 163 const struct cec_adap_ops *ops; 164 void *priv; 165 u32 capabilities; 166 u8 available_log_addrs; 167 168 u16 phys_addr; 169 bool is_configuring; 170 bool is_configured; 171 u32 monitor_all_cnt; 172 u32 follower_cnt; 173 struct cec_fh *cec_follower; 174 struct cec_fh *cec_initiator; 175 bool passthrough; 176 struct cec_log_addrs log_addrs; 177 178 struct dentry *cec_dir; 179 struct dentry *status_file; 180 181 u16 phys_addrs[15]; 182 u32 sequence; 183 184 char input_name[32]; 185 char input_phys[32]; 186 char input_drv[32]; 187 }; 188 189 static inline bool cec_has_log_addr(const struct cec_adapter *adap, u8 log_addr) 190 { 191 return adap->log_addrs.log_addr_mask & (1 << log_addr); 192 } 193 194 static inline bool cec_is_sink(const struct cec_adapter *adap) 195 { 196 return adap->phys_addr == 0; 197 } 198 199 #if IS_ENABLED(CONFIG_MEDIA_CEC) 200 struct cec_adapter *cec_allocate_adapter(const struct cec_adap_ops *ops, 201 void *priv, const char *name, u32 caps, u8 available_las, 202 struct device *parent); 203 int cec_register_adapter(struct cec_adapter *adap); 204 void cec_unregister_adapter(struct cec_adapter *adap); 205 void cec_delete_adapter(struct cec_adapter *adap); 206 207 int cec_s_log_addrs(struct cec_adapter *adap, struct cec_log_addrs *log_addrs, 208 bool block); 209 void cec_s_phys_addr(struct cec_adapter *adap, u16 phys_addr, 210 bool block); 211 int cec_transmit_msg(struct cec_adapter *adap, struct cec_msg *msg, 212 bool block); 213 214 /* Called by the adapter */ 215 void cec_transmit_done(struct cec_adapter *adap, u8 status, u8 arb_lost_cnt, 216 u8 nack_cnt, u8 low_drive_cnt, u8 error_cnt); 217 void cec_received_msg(struct cec_adapter *adap, struct cec_msg *msg); 218 219 #else 220 221 static inline int cec_register_adapter(struct cec_adapter *adap) 222 { 223 return 0; 224 } 225 226 static inline void cec_unregister_adapter(struct cec_adapter *adap) 227 { 228 } 229 230 static inline void cec_delete_adapter(struct cec_adapter *adap) 231 { 232 } 233 234 static inline void cec_s_phys_addr(struct cec_adapter *adap, u16 phys_addr, 235 bool block) 236 { 237 } 238 239 #endif 240 241 #endif /* _MEDIA_CEC_H */ 242