LXR linux/include/media/cec.h

   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 * @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 */
  49struct 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
  62struct cec_adapter;
  63struct cec_data;
  64
  65struct 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
  79struct 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
  86struct 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
 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_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
 142struct 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        struct dentry *cec_dir;
 177        struct dentry *status_file;
 178
 179        u16 phys_addrs[15];
 180        u32 sequence;
 181
 182        char input_name[32];
 183        char input_phys[32];
 184        char input_drv[32];
 185};
 186
 187static inline bool cec_has_log_addr(const struct cec_adapter *adap, u8 log_addr)
 188{
 189        return adap->log_addrs.log_addr_mask & (1 << log_addr);
 190}
 191
 192static inline bool cec_is_sink(const struct cec_adapter *adap)
 193{
 194        return adap->phys_addr == 0;
 195}
 196
 197#if IS_ENABLED(CONFIG_MEDIA_CEC_SUPPORT)
 198struct cec_adapter *cec_allocate_adapter(const struct cec_adap_ops *ops,
 199                void *priv, const char *name, u32 caps, u8 available_las);
 200int cec_register_adapter(struct cec_adapter *adap, struct device *parent);
 201void cec_unregister_adapter(struct cec_adapter *adap);
 202void cec_delete_adapter(struct cec_adapter *adap);
 203
 204int cec_s_log_addrs(struct cec_adapter *adap, struct cec_log_addrs *log_addrs,
 205                    bool block);
 206void cec_s_phys_addr(struct cec_adapter *adap, u16 phys_addr,
 207                     bool block);
 208int cec_transmit_msg(struct cec_adapter *adap, struct cec_msg *msg,
 209                     bool block);
 210
 211/* Called by the adapter */
 212void cec_transmit_done(struct cec_adapter *adap, u8 status, u8 arb_lost_cnt,
 213                       u8 nack_cnt, u8 low_drive_cnt, u8 error_cnt);
 214void cec_received_msg(struct cec_adapter *adap, struct cec_msg *msg);
 215
 216#else
 217
 218static inline int cec_register_adapter(struct cec_adapter *adap,
 219                                       struct device *parent)
 220{
 221        return 0;
 222}
 223
 224static inline void cec_unregister_adapter(struct cec_adapter *adap)
 225{
 226}
 227
 228static inline void cec_delete_adapter(struct cec_adapter *adap)
 229{
 230}
 231
 232static inline void cec_s_phys_addr(struct cec_adapter *adap, u16 phys_addr,
 233                                   bool block)
 234{
 235}
 236
 237#endif
 238
 239#endif /* _MEDIA_CEC_H */
 240