/* SPDX-License-Identifier: GPL-2.0-only */
/*
* cec - HDMI Consumer Electronics Control support header
*
* Copyright 2016 Cisco Systems, Inc. and/or its affiliates. All rights reserved.
*/
#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>
#define CEC_CAP_DEFAULTS (CEC_CAP_LOG_ADDRS | CEC_CAP_TRANSMIT | \
CEC_CAP_PASSTHROUGH | CEC_CAP_RC)
/**
* struct cec_devnode - cec device node
* @dev: cec device
* @cdev: cec character device
* @minor: device node minor number
* @lock: lock to serialize open/release and registration
* @registered: the device was correctly registered
* @unregistered: the device was unregistered
* @lock_fhs: lock to control access to @fhs
* @fhs: the list of open filehandles (cec_fh)
*
* This structure represents a cec-related device node.
*
* To add or remove filehandles from @fhs the @lock must be taken first,
* followed by @lock_fhs. It is safe to access @fhs if either lock is held.
*
* 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;
/* serialize open/release and registration */
struct mutex lock;
bool registered;
bool unregistered;
/* protect access to fhs */
struct mutex lock_fhs;
struct list_head fhs;
};
struct cec_adapter;
struct cec_data;
struct cec_pin;
struct cec_notifier;
struct cec_data {
struct list_head list;
struct list_head xfer_list;
struct cec_adapter *adap;
struct cec_msg msg;
u8 match_len;
u8 match_reply[5];
struct cec_fh *fh;
struct delayed_work work;
struct completion c;
u8 attempts;
bool blocking;
bool completed;
};
struct cec_msg_entry {
struct list_head list;
struct cec_msg msg;
};
struct cec_event_entry {
struct list_head list;
struct cec_event ev;
};
#define CEC_NUM_CORE_EVENTS 2
#define CEC_NUM_EVENTS CEC_EVENT_PIN_5V_HIGH
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;
struct mutex lock;
struct list_head events[CEC_NUM_EVENTS]; /* queued events */
u16 queued_events[CEC_NUM_EVENTS];
unsigned int total_queued_events;
struct cec_event_entry core_events[CEC_NUM_CORE_EVENTS];
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, called with adap->lock held */
int (*adap_enable)(struct cec_adapter *adap, bool enable);
int (*adap_monitor_all_enable)(struct cec_adapter *adap, bool enable);
int (*adap_monitor_pin_enable)(struct cec_adapter *adap, bool enable);
int (*adap_log_addr)(struct cec_adapter *adap, u8 logical_addr);
void (*adap_unconfigured)(struct cec_adapter *adap);
int (*adap_transmit)(struct cec_adapter *adap, u8 attempts,
u32 signal_free_time, struct cec_msg *msg);
void (*adap_nb_transmit_canceled)(struct cec_adapter *adap,
const struct cec_msg *msg);
void (*adap_status)(struct cec_adapter *adap, struct seq_file *file);
void (*adap_free)(struct cec_adapter *adap);
/* Error injection callbacks, called without adap->lock held */
int (*error_inj_show)(struct cec_adapter *adap, struct seq_file *sf);
bool (*error_inj_parse_line)(struct cec_adapter *adap, char *line);
/* High-level CEC message callback, called without adap->lock held */
void (*configured)(struct cec_adapter *adap);
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 - cec adapter structure
* @owner: module owner
* @name: name of the CEC adapter
* @devnode: device node for the /dev/cecX device
* @lock: mutex controlling access to this structure
* @rc: remote control device
* @transmit_queue: queue of pending transmits
* @transmit_queue_sz: number of pending transmits
* @wait_queue: queue of transmits waiting for a reply
* @transmitting: CEC messages currently being transmitted
* @transmit_in_progress: true if a transmit is in progress
* @transmit_in_progress_aborted: true if a transmit is in progress is to be
* aborted. This happens if the logical address is
* invalidated while the transmit is ongoing. In that
* case the transmit will finish, but will not retransmit
* and be marked as ABORTED.
* @xfer_timeout_ms: the transfer timeout in ms.
* If 0, then timeout after 2100 ms.
* @kthread_config: kthread used to configure a CEC adapter
* @config_completion: used to signal completion of the config kthread
* @kthread: main CEC processing thread
* @kthread_waitq: main CEC processing wait_queue
* @ops: cec adapter ops
* @priv: cec driver's private data
* @capabilities: cec adapter capabilities
* @available_log_addrs: maximum number of available logical addresses
* @phys_addr: the current physical address
* @needs_hpd: if true, then the HDMI HotPlug Detect pin must be high
* in order to transmit or receive CEC messages. This is usually a HW
* limitation.
* @is_enabled: the CEC adapter is enabled
* @is_claiming_log_addrs: true if cec_claim_log_addrs() is running
* @is_configuring: the CEC adapter is configuring (i.e. claiming LAs)
* @must_reconfigure: while configuring, the PA changed, so reclaim LAs
* @is_configured: the CEC adapter is configured (i.e. has claimed LAs)
* @cec_pin_is_high: if true then the CEC pin is high. Only used with the
* CEC pin framework.
* @adap_controls_phys_addr: if true, then the CEC adapter controls the
* physical address, i.e. the CEC hardware can detect HPD changes and
* read the EDID and is not dependent on an external HDMI driver.
* Drivers that need this can set this field to true after the
* cec_allocate_adapter() call.
* @last_initiator: the initiator of the last transmitted message.
* @monitor_all_cnt: number of filehandles monitoring all msgs
* @monitor_pin_cnt: number of filehandles monitoring pin changes
* @follower_cnt: number of filehandles in follower mode
* @cec_follower: filehandle of the exclusive follower
* @cec_initiator: filehandle of the exclusive initiator
* @passthrough: if true, then the exclusive follower is in
* passthrough mode.
* @log_addrs: current logical addresses
* @conn_info: current connector info
* @tx_timeout_cnt: count the number of Timed Out transmits.
* Reset to 0 when this is reported in cec_adap_status().
* @tx_low_drive_cnt: count the number of Low Drive transmits.
* Reset to 0 when this is reported in cec_adap_status().
* @tx_error_cnt: count the number of Error transmits.
* Reset to 0 when this is reported in cec_adap_status().
* @tx_arb_lost_cnt: count the number of Arb Lost transmits.
* Reset to 0 when this is reported in cec_adap_status().
* @tx_low_drive_log_cnt: number of logged Low Drive transmits since the
* adapter was enabled. Used to avoid flooding the kernel
* log if this happens a lot.
* @tx_error_log_cnt: number of logged Error transmits since the adapter was
* enabled. Used to avoid flooding the kernel log if this
* happens a lot.
* @notifier: CEC notifier
* @pin: CEC pin status struct
* @cec_dir: debugfs cec directory
* @sequence: transmit sequence counter
* @input_phys: remote control input_phys name
*
* This structure represents a cec adapter.
*/
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;
bool transmit_in_progress;
bool transmit_in_progress_aborted;
unsigned int xfer_timeout_ms;
struct task_struct *kthread_config;
struct completion config_completion;
struct task_struct *kthread;
wait_queue_head_t kthread_waitq;
const struct cec_adap_ops *ops;
void *priv;
u32 capabilities;
u8 available_log_addrs;
u16 phys_addr;
bool needs_hpd;
bool is_enabled;
bool is_claiming_log_addrs;
bool is_configuring;
bool must_reconfigure;
bool is_configured;
bool cec_pin_is_high;
bool adap_controls_phys_addr;
u8 last_initiator;
u32 monitor_all_cnt;
u32 monitor_pin_cnt;
u32 follower_cnt;
struct cec_fh *cec_follower;
struct cec_fh *cec_initiator;
bool passthrough;
struct cec_log_addrs log_addrs;
struct cec_connector_info conn_info;
u32 tx_timeout_cnt;
u32 tx_low_drive_cnt;
u32 tx_error_cnt;
u32 tx_arb_lost_cnt;
u32 tx_low_drive_log_cnt;
u32 tx_error_log_cnt;
#ifdef CONFIG_CEC_NOTIFIER
struct cec_notifier *notifier;
#endif
#ifdef CONFIG_CEC_PIN
struct cec_pin *pin;
#endif
struct dentry *cec_dir;
u32 sequence;
char input_phys[40];
};
static inline int cec_get_device(struct cec_adapter *adap)
{
struct cec_devnode *devnode = &adap->devnode;
/*
* Check if the cec device is available. This needs to be done with
* the devnode->lock held to prevent an open/unregister race:
* without the lock, the device could be unregistered and freed between
* the devnode->registered check and get_device() calls, leading to
* a crash.
*/
mutex_lock(&devnode->lock);
/*
* return ENODEV if the cec device has been removed
* already or if it is not registered anymore.
*/
if (!devnode->registered) {
mutex_unlock(&devnode->lock);
return -ENODEV;
}
/* and increase the device refcount */
get_device(&devnode->dev);
mutex_unlock(&devnode->lock);
return 0;
}
static inline void cec_put_device(struct cec_adapter *adap)
{
put_device(&adap->devnode.dev);
}
static inline void *cec_get_drvdata(const struct cec_adapter *adap)
{
return adap->priv;
}
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;
}
/**
* cec_is_registered() - is the CEC adapter registered?
*
* @adap: the CEC adapter, may be NULL.
*
* Return: true if the adapter is registered, false otherwise.
*/
static inline bool cec_is_registered(const struct cec_adapter *adap)
{
return adap && adap->devnode.registered;
}
#define cec_phys_addr_exp(pa) \
((pa) >> 12), ((pa) >> 8) & 0xf, ((pa) >> 4) & 0xf, (pa) & 0xf
struct edid;
struct drm_connector;
#if IS_REACHABLE(CONFIG_CEC_CORE)
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);
void cec_s_phys_addr_from_edid(struct cec_adapter *adap,
const struct edid *edid);
void cec_s_conn_info(struct cec_adapter *adap,
const struct cec_connector_info *conn_info);
int cec_transmit_msg(struct cec_adapter *adap, struct cec_msg *msg,
bool block);
/* Called by the adapter */
void cec_transmit_done_ts(struct cec_adapter *adap, u8 status,
u8 arb_lost_cnt, u8 nack_cnt, u8 low_drive_cnt,
u8 error_cnt, ktime_t ts);
static inline void cec_transmit_done(struct cec_adapter *adap, u8 status,
u8 arb_lost_cnt, u8 nack_cnt,
u8 low_drive_cnt, u8 error_cnt)
{
cec_transmit_done_ts(adap, status, arb_lost_cnt, nack_cnt,
low_drive_cnt, error_cnt, ktime_get());
}
/*
* Simplified version of cec_transmit_done for hardware that doesn't retry
* failed transmits. So this is always just one attempt in which case
* the status is sufficient.
*/
void cec_transmit_attempt_done_ts(struct cec_adapter *adap,
u8 status, ktime_t ts);
static inline void cec_transmit_attempt_done(struct cec_adapter *adap,
u8 status)
{
cec_transmit_attempt_done_ts(adap, status, ktime_get());
}
void cec_received_msg_ts(struct cec_adapter *adap,
struct cec_msg *msg, ktime_t ts);
static inline void cec_received_msg(struct cec_adapter *adap,
struct cec_msg *msg)
{
cec_received_msg_ts(adap, msg, ktime_get());
}
/**
* cec_queue_pin_cec_event() - queue a CEC pin event with a given timestamp.
*
* @adap: pointer to the cec adapter
* @is_high: when true the CEC pin is high, otherwise it is low
* @dropped_events: when true some events were dropped
* @ts: the timestamp for this event
*
*/
void cec_queue_pin_cec_event(struct cec_adapter *adap, bool is_high,
bool dropped_events, ktime_t ts);
/**
* cec_queue_pin_hpd_event() - queue a pin event with a given timestamp.
*
* @adap: pointer to the cec adapter
* @is_high: when true the HPD pin is high, otherwise it is low
* @ts: the timestamp for this event
*
*/
void cec_queue_pin_hpd_event(struct cec_adapter *adap, bool is_high, ktime_t ts);
/**
* cec_queue_pin_5v_event() - queue a pin event with a given timestamp.
*
* @adap: pointer to the cec adapter
* @is_high: when true the 5V pin is high, otherwise it is low
* @ts: the timestamp for this event
*
*/
void cec_queue_pin_5v_event(struct cec_adapter *adap, bool is_high, ktime_t ts);
/**
* cec_get_edid_phys_addr() - find and return the physical address
*
* @edid: pointer to the EDID data
* @size: size in bytes of the EDID data
* @offset: If not %NULL then the location of the physical address
* bytes in the EDID will be returned here. This is set to 0
* if there is no physical address found.
*
* Return: the physical address or CEC_PHYS_ADDR_INVALID if there is none.
*/
u16 cec_get_edid_phys_addr(const u8 *edid, unsigned int size,
unsigned int *offset);
void cec_fill_conn_info_from_drm(struct cec_connector_info *conn_info,
const struct drm_connector *connector);
#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)
{
}
static inline void cec_s_phys_addr_from_edid(struct cec_adapter *adap,
const struct edid *edid)
{
}
static inline u16 cec_get_edid_phys_addr(const u8 *edid, unsigned int size,
unsigned int *offset)
{
if (offset)
*offset = 0;
return CEC_PHYS_ADDR_INVALID;
}
static inline void cec_s_conn_info(struct cec_adapter *adap,
const struct cec_connector_info *conn_info)
{
}
static inline void
cec_fill_conn_info_from_drm(struct cec_connector_info *conn_info,
const struct drm_connector *connector)
{
memset(conn_info, 0, sizeof(*conn_info));
}
#endif
/**
* cec_phys_addr_invalidate() - set the physical address to INVALID
*
* @adap: the CEC adapter
*
* This is a simple helper function to invalidate the physical
* address.
*/
static inline void cec_phys_addr_invalidate(struct cec_adapter *adap)
{
cec_s_phys_addr(adap, CEC_PHYS_ADDR_INVALID, false);
}
/**
* cec_get_edid_spa_location() - find location of the Source Physical Address
*
* @edid: the EDID
* @size: the size of the EDID
*
* This EDID is expected to be a CEA-861 compliant, which means that there are
* at least two blocks and one or more of the extensions blocks are CEA-861
* blocks.
*
* The returned location is guaranteed to be <= size-2.
*
* This is an inline function since it is used by both CEC and V4L2.
* Ideally this would go in a module shared by both, but it is overkill to do
* that for just a single function.
*/
static inline unsigned int cec_get_edid_spa_location(const u8 *edid,
unsigned int size)
{
unsigned int blocks = size / 128;
unsigned int block;
u8 d;
/* Sanity check: at least 2 blocks and a multiple of the block size */
if (blocks < 2 || size % 128)
return 0;
/*
* If there are fewer extension blocks than the size, then update
* 'blocks'. It is allowed to have more extension blocks than the size,
* since some hardware can only read e.g. 256 bytes of the EDID, even
* though more blocks are present. The first CEA-861 extension block
* should normally be in block 1 anyway.
*/
if (edid[0x7e] + 1 < blocks)
blocks = edid[0x7e] + 1;
for (block = 1; block < blocks; block++) {
unsigned int offset = block * 128;
/* Skip any non-CEA-861 extension blocks */
if (edid[offset] != 0x02 || edid[offset + 1] != 0x03)
continue;
/* search Vendor Specific Data Block (tag 3) */
d = edid[offset + 2] & 0x7f;
/* Check if there are Data Blocks */
if (d <= 4)
continue;
if (d > 4) {
unsigned int i = offset + 4;
unsigned int end = offset + d;
/* Note: 'end' is always < 'size' */
do {
u8 tag = edid[i] >> 5;
u8 len = edid[i] & 0x1f;
if (tag == 3 && len >= 5 && i + len <= end &&
edid[i + 1] == 0x03 &&
edid[i + 2] == 0x0c &&
edid[i + 3] == 0x00)
return i + 4;
i += len + 1;
} while (i < end);
}
}
return 0;
}
#endif /* _MEDIA_CEC_H */
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