linux/include/media/cec.h

240 lines
6.4 KiB
C

/*
* cec - HDMI Consumer Electronics Control support header
*
* Copyright 2016 Cisco Systems, Inc. and/or its affiliates. All rights reserved.
*
* This program is free software; you may redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; version 2 of the License.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
* NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
* BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
* ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
* CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
* SOFTWARE.
*/
#ifndef _MEDIA_CEC_H
#define _MEDIA_CEC_H
#include <linux/poll.h>
#include <linux/fs.h>
#include <linux/debugfs.h>
#include <linux/device.h>
#include <linux/cdev.h>
#include <linux/kthread.h>
#include <linux/timer.h>
#include <linux/cec-funcs.h>
#include <media/rc-core.h>
#include <media/cec-edid.h>
/**
* struct cec_devnode - cec device node
* @dev: cec device
* @cdev: cec character device
* @minor: device node minor number
* @registered: the device was correctly registered
* @unregistered: the device was unregistered
* @fhs_lock: lock to control access to the filehandle list
* @fhs: the list of open filehandles (cec_fh)
*
* This structure represents a cec-related device node.
*
* The @parent is a physical device. It must be set by core or device drivers
* before registering the node.
*/
struct cec_devnode {
/* sysfs */
struct device dev;
struct cdev cdev;
/* device info */
int minor;
bool registered;
bool unregistered;
struct list_head fhs;
struct mutex lock;
};
struct cec_adapter;
struct cec_data;
struct cec_data {
struct list_head list;
struct list_head xfer_list;
struct cec_adapter *adap;
struct cec_msg msg;
struct cec_fh *fh;
struct delayed_work work;
struct completion c;
u8 attempts;
bool new_initiator;
bool blocking;
bool completed;
};
struct cec_msg_entry {
struct list_head list;
struct cec_msg msg;
};
#define CEC_NUM_EVENTS CEC_EVENT_LOST_MSGS
struct cec_fh {
struct list_head list;
struct list_head xfer_list;
struct cec_adapter *adap;
u8 mode_initiator;
u8 mode_follower;
/* Events */
wait_queue_head_t wait;
unsigned int pending_events;
struct cec_event events[CEC_NUM_EVENTS];
struct mutex lock;
struct list_head msgs; /* queued messages */
unsigned int queued_msgs;
};
#define CEC_SIGNAL_FREE_TIME_RETRY 3
#define CEC_SIGNAL_FREE_TIME_NEW_INITIATOR 5
#define CEC_SIGNAL_FREE_TIME_NEXT_XFER 7
/* The nominal data bit period is 2.4 ms */
#define CEC_FREE_TIME_TO_USEC(ft) ((ft) * 2400)
struct cec_adap_ops {
/* Low-level callbacks */
int (*adap_enable)(struct cec_adapter *adap, bool enable);
int (*adap_monitor_all_enable)(struct cec_adapter *adap, bool enable);
int (*adap_log_addr)(struct cec_adapter *adap, u8 logical_addr);
int (*adap_transmit)(struct cec_adapter *adap, u8 attempts,
u32 signal_free_time, struct cec_msg *msg);
void (*adap_status)(struct cec_adapter *adap, struct seq_file *file);
/* High-level CEC message callback */
int (*received)(struct cec_adapter *adap, struct cec_msg *msg);
};
/*
* The minimum message length you can receive (excepting poll messages) is 2.
* With a transfer rate of at most 36 bytes per second this makes 18 messages
* per second worst case.
*
* We queue at most 3 seconds worth of received messages. The CEC specification
* requires that messages are replied to within a second, so 3 seconds should
* give more than enough margin. Since most messages are actually more than 2
* bytes, this is in practice a lot more than 3 seconds.
*/
#define CEC_MAX_MSG_RX_QUEUE_SZ (18 * 3)
/*
* The transmit queue is limited to 1 second worth of messages (worst case).
* Messages can be transmitted by userspace and kernel space. But for both it
* makes no sense to have a lot of messages queued up. One second seems
* reasonable.
*/
#define CEC_MAX_MSG_TX_QUEUE_SZ (18 * 1)
struct cec_adapter {
struct module *owner;
char name[32];
struct cec_devnode devnode;
struct mutex lock;
struct rc_dev *rc;
struct list_head transmit_queue;
unsigned int transmit_queue_sz;
struct list_head wait_queue;
struct cec_data *transmitting;
struct task_struct *kthread_config;
struct completion config_completion;
struct task_struct *kthread;
wait_queue_head_t kthread_waitq;
wait_queue_head_t waitq;
const struct cec_adap_ops *ops;
void *priv;
u32 capabilities;
u8 available_log_addrs;
u16 phys_addr;
bool is_configuring;
bool is_configured;
u32 monitor_all_cnt;
u32 follower_cnt;
struct cec_fh *cec_follower;
struct cec_fh *cec_initiator;
bool passthrough;
struct cec_log_addrs log_addrs;
struct dentry *cec_dir;
struct dentry *status_file;
u16 phys_addrs[15];
u32 sequence;
char input_name[32];
char input_phys[32];
char input_drv[32];
};
static inline bool cec_has_log_addr(const struct cec_adapter *adap, u8 log_addr)
{
return adap->log_addrs.log_addr_mask & (1 << log_addr);
}
static inline bool cec_is_sink(const struct cec_adapter *adap)
{
return adap->phys_addr == 0;
}
#if IS_ENABLED(CONFIG_MEDIA_CEC_SUPPORT)
struct cec_adapter *cec_allocate_adapter(const struct cec_adap_ops *ops,
void *priv, const char *name, u32 caps, u8 available_las);
int cec_register_adapter(struct cec_adapter *adap, struct device *parent);
void cec_unregister_adapter(struct cec_adapter *adap);
void cec_delete_adapter(struct cec_adapter *adap);
int cec_s_log_addrs(struct cec_adapter *adap, struct cec_log_addrs *log_addrs,
bool block);
void cec_s_phys_addr(struct cec_adapter *adap, u16 phys_addr,
bool block);
int cec_transmit_msg(struct cec_adapter *adap, struct cec_msg *msg,
bool block);
/* Called by the adapter */
void cec_transmit_done(struct cec_adapter *adap, u8 status, u8 arb_lost_cnt,
u8 nack_cnt, u8 low_drive_cnt, u8 error_cnt);
void cec_received_msg(struct cec_adapter *adap, struct cec_msg *msg);
#else
static inline int cec_register_adapter(struct cec_adapter *adap,
struct device *parent)
{
return 0;
}
static inline void cec_unregister_adapter(struct cec_adapter *adap)
{
}
static inline void cec_delete_adapter(struct cec_adapter *adap)
{
}
static inline void cec_s_phys_addr(struct cec_adapter *adap, u16 phys_addr,
bool block)
{
}
#endif
#endif /* _MEDIA_CEC_H */