/* SPDX-License-Identifier: GPL-2.0 */

  #ifndef SOUND_FIREWIRE_AMDTP_H_INCLUDED
  #define SOUND_FIREWIRE_AMDTP_H_INCLUDED

  #include <linux/err.h>

  #include <linux/interrupt.h>

  #include <linux/mutex.h>

  #include <linux/sched.h>

  #include <sound/asound.h>

  #include "packets-buffer.h"
  
  /**

   * enum cip_flags - describes details of the streaming protocol

   * @CIP_NONBLOCKING: In non-blocking mode, each packet contains
   *	sample_rate/8000 samples, with rounding up or down to adjust
   *	for clock skew and left-over fractional samples.  This should
   *	be used if supported by the device.

   * @CIP_BLOCKING: In blocking mode, each packet contains either zero or
   *	SYT_INTERVAL samples, with these two types alternating so that
   *	the overall sample rate comes out right.

   * @CIP_EMPTY_WITH_TAG0: Only for in-stream. Empty in-packets have TAG0.

   * @CIP_DBC_IS_END_EVENT: The value of dbc in an packet corresponds to the end
   * of event in the packet. Out of IEC 61883.

   * @CIP_WRONG_DBS: Only for in-stream. The value of dbs is wrong in in-packets.
   *	The value of data_block_quadlets is used instead of reported value.

   * @CIP_SKIP_DBC_ZERO_CHECK: Only for in-stream.  Packets with zero in dbc is

   *	skipped for detecting discontinuity.

   * @CIP_EMPTY_HAS_WRONG_DBC: Only for in-stream. The value of dbc in empty
   *	packet is wrong but the others are correct.

   * @CIP_JUMBO_PAYLOAD: Only for in-stream. The number of data blocks in an
   *	packet is larger than IEC 61883-6 defines. Current implementation
   *	allows 5 times as large as IEC 61883-6 defines.

   * @CIP_HEADER_WITHOUT_EOH: Only for in-stream. CIP Header doesn't include
   *	valid EOH.

   * @CIP_NO_HEADERS: a lack of headers in packets

   * @CIP_UNALIGHED_DBC: Only for in-stream. The value of dbc is not alighed to
   *	the value of current SYT_INTERVAL; e.g. initial value is not zero.

   */

  enum cip_flags {

  	CIP_NONBLOCKING		= 0x00,
  	CIP_BLOCKING		= 0x01,

  	CIP_EMPTY_WITH_TAG0	= 0x02,
  	CIP_DBC_IS_END_EVENT	= 0x04,
  	CIP_WRONG_DBS		= 0x08,
  	CIP_SKIP_DBC_ZERO_CHECK	= 0x10,

  	CIP_EMPTY_HAS_WRONG_DBC	= 0x20,
  	CIP_JUMBO_PAYLOAD	= 0x40,

  	CIP_HEADER_WITHOUT_EOH	= 0x80,

  	CIP_NO_HEADER		= 0x100,

  	CIP_UNALIGHED_DBC	= 0x200,

  };
  
  /**

   * enum cip_sfc - supported Sampling Frequency Codes (SFCs)
   * @CIP_SFC_32000:   32,000 data blocks
   * @CIP_SFC_44100:   44,100 data blocks
   * @CIP_SFC_48000:   48,000 data blocks
   * @CIP_SFC_88200:   88,200 data blocks
   * @CIP_SFC_96000:   96,000 data blocks
   * @CIP_SFC_176400: 176,400 data blocks
   * @CIP_SFC_192000: 192,000 data blocks
   * @CIP_SFC_COUNT: the number of supported SFCs
   *
   * These values are used to show nominal Sampling Frequency Code in
   * Format Dependent Field (FDF) of AMDTP packet header. In IEC 61883-6:2002,
   * this code means the number of events per second. Actually the code
   * represents the number of data blocks transferred per second in an AMDTP
   * stream.
   *
   * In IEC 61883-6:2005, some extensions were added to support more types of
   * data such as 'One Bit LInear Audio', therefore the meaning of SFC became
   * different depending on the types.
   *
   * Currently our implementation is compatible with IEC 61883-6:2002.

   */
  enum cip_sfc {
  	CIP_SFC_32000  = 0,
  	CIP_SFC_44100  = 1,
  	CIP_SFC_48000  = 2,
  	CIP_SFC_88200  = 3,
  	CIP_SFC_96000  = 4,
  	CIP_SFC_176400 = 5,
  	CIP_SFC_192000 = 6,

  	CIP_SFC_COUNT

  };

  struct fw_unit;
  struct fw_iso_context;
  struct snd_pcm_substream;

  struct snd_pcm_runtime;

  enum amdtp_stream_direction {
  	AMDTP_OUT_STREAM = 0,
  	AMDTP_IN_STREAM
  };

  struct pkt_desc {
  	u32 cycle;
  	u32 syt;
  	unsigned int data_blocks;
  	unsigned int data_block_counter;
  	__be32 *ctx_payload;
  };

  struct amdtp_stream;

  typedef unsigned int (*amdtp_stream_process_ctx_payloads_t)(

  						struct amdtp_stream *s,

  						const struct pkt_desc *desc,

  						unsigned int packets,

  						struct snd_pcm_substream *pcm);

  struct amdtp_stream {

  	struct fw_unit *unit;

  	enum cip_flags flags;

  	enum amdtp_stream_direction direction;

  	struct mutex mutex;

  	/* For packet processing. */
  	struct fw_iso_context *context;

  	struct iso_packets_buffer buffer;

  	int packet_index;

  	struct pkt_desc *pkt_descs;

  	int tag;

  	union {
  		struct {
  			unsigned int ctx_header_size;
  
  			// limit for payload of iso packet.

  			unsigned int max_ctx_payload_length;

  
  			// For quirks of CIP headers.
  			// Fixed interval of dbc between previos/current
  			// packets.
  			unsigned int dbc_interval;

  		} tx;
  		struct {
  			// To calculate CIP data blocks and tstamp.
  			unsigned int transfer_delay;
  			unsigned int data_block_state;
  			unsigned int last_syt_offset;
  			unsigned int syt_offset_state;
  
  			// To generate CIP header.
  			unsigned int fdf;

  			int syt_override;

  		} rx;
  	} ctx_data;

  
  	/* For CIP headers. */
  	unsigned int source_node_id_field;
  	unsigned int data_block_quadlets;

  	unsigned int data_block_counter;

  	unsigned int sph;

  	unsigned int fmt;

  	/* Internal flags. */
  	enum cip_sfc sfc;
  	unsigned int syt_interval;

  	/* For a PCM substream processing. */
  	struct snd_pcm_substream *pcm;
  	struct tasklet_struct period_tasklet;

  	snd_pcm_uframes_t pcm_buffer_pointer;

  	unsigned int pcm_period_pointer;

  	/* To wait for first packet. */
  	bool callbacked;
  	wait_queue_head_t callback_wait;

  	u32 start_cycle;

  	/* For backends to process data blocks. */
  	void *protocol;

  	amdtp_stream_process_ctx_payloads_t process_ctx_payloads;

  
  	// For domain.

  	int channel;
  	int speed;

  	struct list_head list;

  };

  int amdtp_stream_init(struct amdtp_stream *s, struct fw_unit *unit,

  		      enum amdtp_stream_direction dir, enum cip_flags flags,
  		      unsigned int fmt,

  		      amdtp_stream_process_ctx_payloads_t process_ctx_payloads,

  		      unsigned int protocol_size);

  void amdtp_stream_destroy(struct amdtp_stream *s);

  int amdtp_stream_set_parameters(struct amdtp_stream *s, unsigned int rate,
  				unsigned int data_block_quadlets);

  unsigned int amdtp_stream_get_max_payload(struct amdtp_stream *s);

  void amdtp_stream_update(struct amdtp_stream *s);

  int amdtp_stream_add_pcm_hw_constraints(struct amdtp_stream *s,
  					struct snd_pcm_runtime *runtime);

  void amdtp_stream_pcm_prepare(struct amdtp_stream *s);
  unsigned long amdtp_stream_pcm_pointer(struct amdtp_stream *s);

  int amdtp_stream_pcm_ack(struct amdtp_stream *s);

  void amdtp_stream_pcm_abort(struct amdtp_stream *s);

  extern const unsigned int amdtp_syt_intervals[CIP_SFC_COUNT];

  extern const unsigned int amdtp_rate_table[CIP_SFC_COUNT];

  /**
   * amdtp_stream_running - check stream is running or not
   * @s: the AMDTP stream
   *
   * If this function returns true, the stream is running.
   */
  static inline bool amdtp_stream_running(struct amdtp_stream *s)

  {
  	return !IS_ERR(s->context);
  }

  /**

   * amdtp_streaming_error - check for streaming error
   * @s: the AMDTP stream

   *
   * If this function returns true, the stream's packet queue has stopped due to
   * an asynchronous error.
   */

  static inline bool amdtp_streaming_error(struct amdtp_stream *s)

  {
  	return s->packet_index < 0;
  }
  
  /**

   * amdtp_stream_pcm_running - check PCM substream is running or not
   * @s: the AMDTP stream
   *
   * If this function returns true, PCM substream in the AMDTP stream is running.
   */
  static inline bool amdtp_stream_pcm_running(struct amdtp_stream *s)
  {
  	return !!s->pcm;
  }
  
  /**

   * amdtp_stream_pcm_trigger - start/stop playback from a PCM device
   * @s: the AMDTP stream

   * @pcm: the PCM device to be started, or %NULL to stop the current device
   *
   * Call this function on a running isochronous stream to enable the actual
   * transmission of PCM data.  This function should be called from the PCM
   * device's .trigger callback.
   */

  static inline void amdtp_stream_pcm_trigger(struct amdtp_stream *s,
  					    struct snd_pcm_substream *pcm)

  {

  	WRITE_ONCE(s->pcm, pcm);

  }

  static inline bool cip_sfc_is_base_44100(enum cip_sfc sfc)
  {
  	return sfc & 1;
  }

  /**
   * amdtp_stream_wait_callback - sleep till callbacked or timeout
   * @s: the AMDTP stream
   * @timeout: msec till timeout
   *
   * If this function return false, the AMDTP stream should be stopped.
   */
  static inline bool amdtp_stream_wait_callback(struct amdtp_stream *s,
  					      unsigned int timeout)
  {
  	return wait_event_timeout(s->callback_wait,
  				  s->callbacked == true,
  				  msecs_to_jiffies(timeout)) > 0;
  }

  struct amdtp_domain {
  	struct list_head streams;
  };
  
  int amdtp_domain_init(struct amdtp_domain *d);
  void amdtp_domain_destroy(struct amdtp_domain *d);

  int amdtp_domain_add_stream(struct amdtp_domain *d, struct amdtp_stream *s,
  			    int channel, int speed);

  int amdtp_domain_start(struct amdtp_domain *d);

  void amdtp_domain_stop(struct amdtp_domain *d);

  #endif