/* 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>

  #include <media/cec-notifier.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
   * @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_pin;

  
  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 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 */
  	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);
  	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);

  	void (*adap_free)(struct cec_adapter *adap);

  	/* Error injection callbacks */
  	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 */
  	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;

  	bool transmit_in_progress;

  
  	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 needs_hpd;

  	bool is_configuring;
  	bool is_configured;

  	bool cec_pin_is_high;

  	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;

  	u32 tx_timeouts;

  #ifdef CONFIG_CEC_NOTIFIER

  	struct cec_notifier *notifier;
  #endif

  #ifdef CONFIG_CEC_PIN
  	struct cec_pin *pin;
  #endif

  	struct dentry *cec_dir;
  	struct dentry *status_file;

  	struct dentry *error_inj_file;

  
  	u16 phys_addrs[15];
  	u32 sequence;

  	char device_name[32];

  	char input_phys[32];
  	char input_drv[32];
  };

  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;

  #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);

  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);
  
  /**
   * cec_set_edid_phys_addr() - find and set the physical address
   *
   * @edid:	pointer to the EDID data
   * @size:	size in bytes of the EDID data
   * @phys_addr:	the new physical address
   *
   * This function finds the location of the physical address in the EDID
   * and fills in the given physical address and updates the checksum
   * at the end of the EDID block. It does nothing if the EDID doesn't
   * contain a physical address.
   */
  void cec_set_edid_phys_addr(u8 *edid, unsigned int size, u16 phys_addr);
  
  /**
   * cec_phys_addr_for_input() - calculate the PA for an input
   *
   * @phys_addr:	the physical address of the parent
   * @input:	the number of the input port, must be between 1 and 15
   *
   * This function calculates a new physical address based on the input
   * port number. For example:
   *
   * PA = 0.0.0.0 and input = 2 becomes 2.0.0.0
   *
   * PA = 3.0.0.0 and input = 1 becomes 3.1.0.0
   *
   * PA = 3.2.1.0 and input = 5 becomes 3.2.1.5
   *
   * PA = 3.2.1.3 and input = 5 becomes f.f.f.f since it maxed out the depth.
   *
   * Return: the new physical address or CEC_PHYS_ADDR_INVALID.
   */
  u16 cec_phys_addr_for_input(u16 phys_addr, u8 input);
  
  /**
   * cec_phys_addr_validate() - validate a physical address from an EDID
   *
   * @phys_addr:	the physical address to validate
   * @parent:	if not %NULL, then this is filled with the parents PA.
   * @port:	if not %NULL, then this is filled with the input port.
   *
   * This validates a physical address as read from an EDID. If the
   * PA is invalid (such as 1.0.1.0 since '0' is only allowed at the end),
   * then it will return -EINVAL.
   *
   * The parent PA is passed into %parent and the input port is passed into
   * %port. For example:
   *
   * PA = 0.0.0.0: has parent 0.0.0.0 and input port 0.
   *
   * PA = 1.0.0.0: has parent 0.0.0.0 and input port 1.
   *
   * PA = 3.2.0.0: has parent 3.0.0.0 and input port 2.
   *
   * PA = f.f.f.f: has parent f.f.f.f and input port 0.
   *
   * Return: 0 if the PA is valid, -EINVAL if not.
   */
  int cec_phys_addr_validate(u16 phys_addr, u16 *parent, u16 *port);

  #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_set_edid_phys_addr(u8 *edid, unsigned int size,
  					  u16 phys_addr)
  {
  }
  
  static inline u16 cec_phys_addr_for_input(u16 phys_addr, u8 input)
  {
  	return CEC_PHYS_ADDR_INVALID;
  }
  
  static inline int cec_phys_addr_validate(u16 phys_addr, u16 *parent, u16 *port)
  {

  	if (parent)
  		*parent = phys_addr;
  	if (port)
  		*port = 0;

  	return 0;
  }

  #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 */