/* 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_HEADER: 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.
 * @CIP_UNAWARE_SYT: For outgoing packet, the value in SYT field of CIP is 0xffff.
 *      For incoming packet, the value in SYT field of CIP is not handled.
 * @CIP_DBC_IS_PAYLOAD_QUADLETS: Available for incoming packet, and only effective with
 *      CIP_DBC_IS_END_EVENT flag. The value of dbc field is the number of accumulated quadlets
 *      in CIP payload, instead of the number of accumulated data blocks.
 */
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,
        CIP_UNAWARE_SYT         = 0x400,
        CIP_DBC_IS_PAYLOAD_QUADLETS = 0x800,
};

/**
 * 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 list_head link;
};

struct amdtp_stream;
typedef void (*amdtp_stream_process_ctx_payloads_t)(struct amdtp_stream *s,
                                                    const struct pkt_desc *desc,
                                                    unsigned int count,
                                                    struct snd_pcm_substream *pcm);

struct amdtp_domain;
struct amdtp_stream {
        struct fw_unit *unit;
        // The combination of cip_flags enumeration-constants.
        unsigned int flags;
        enum amdtp_stream_direction direction;
        struct mutex mutex;

        /* For packet processing. */
        struct fw_iso_context *context;
        struct iso_packets_buffer buffer;
        unsigned int queue_size;
        int packet_index;
        struct pkt_desc *packet_descs;
        struct list_head packet_descs_list;
        struct pkt_desc *packet_descs_cursor;
        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;

                        // The device starts multiplexing events to the packet.
                        bool event_starts;

                        struct {
                                struct seq_desc *descs;
                                unsigned int size;
                                unsigned int pos;
                        } cache;
                } tx;
                struct {
                        // To generate CIP header.
                        unsigned int fdf;

                        // To generate constant hardware IRQ.
                        unsigned int event_count;

                        // To calculate CIP data blocks and tstamp.
                        struct {
                                struct seq_desc *descs;
                                unsigned int size;
                                unsigned int pos;
                        } seq;

                        unsigned int data_block_state;
                        unsigned int syt_offset_state;
                        unsigned int last_syt_offset;

                        struct amdtp_stream *replay_target;
                        unsigned int cache_pos;
                } 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.
        unsigned int transfer_delay;
        enum cip_sfc sfc;
        unsigned int syt_interval;

        /* For a PCM substream processing. */
        struct snd_pcm_substream *pcm;
        struct work_struct period_work;
        snd_pcm_uframes_t pcm_buffer_pointer;
        unsigned int pcm_period_pointer;
        unsigned int pcm_frame_multiplier;

        // To start processing content of packets at the same cycle in several contexts for
        // each direction.
        bool ready_processing;
        wait_queue_head_t ready_wait;
        unsigned int next_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;
        struct amdtp_domain *domain;
};

int amdtp_stream_init(struct amdtp_stream *s, struct fw_unit *unit,
                      enum amdtp_stream_direction dir, unsigned int 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 pcm_frame_multiplier);
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);
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);
}

/**
 * amdtp_stream_next_packet_desc - retrieve next descriptor for amdtp packet.
 * @s: the AMDTP stream
 * @desc: the descriptor of packet
 *
 * This macro computes next descriptor so that the list of descriptors behaves circular queue.
 */
#define amdtp_stream_next_packet_desc(s, desc) \
        list_next_entry_circular(desc, &s->packet_descs_list, link)

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

struct seq_desc {
        unsigned int syt_offset;
        unsigned int data_blocks;
};

struct amdtp_domain {
        struct list_head streams;

        unsigned int events_per_period;
        unsigned int events_per_buffer;

        struct amdtp_stream *irq_target;

        struct {
                unsigned int tx_init_skip;
                unsigned int tx_start;
                unsigned int rx_start;
        } processing_cycle;

        struct {
                bool enable:1;
                bool on_the_fly:1;
        } replay;
};

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, unsigned int tx_init_skip_cycles, bool replay_seq,
                       bool replay_on_the_fly);
void amdtp_domain_stop(struct amdtp_domain *d);

static inline int amdtp_domain_set_events_per_period(struct amdtp_domain *d,
                                                unsigned int events_per_period,
                                                unsigned int events_per_buffer)
{
        d->events_per_period = events_per_period;
        d->events_per_buffer = events_per_buffer;

        return 0;
}

unsigned long amdtp_domain_stream_pcm_pointer(struct amdtp_domain *d,
                                              struct amdtp_stream *s);
int amdtp_domain_stream_pcm_ack(struct amdtp_domain *d, struct amdtp_stream *s);

/**
 * amdtp_domain_wait_ready - sleep till being ready to process packets or timeout
 * @d: the AMDTP domain
 * @timeout_ms: msec till timeout
 *
 * If this function return false, the AMDTP domain should be stopped.
 */
static inline bool amdtp_domain_wait_ready(struct amdtp_domain *d, unsigned int timeout_ms)
{
        struct amdtp_stream *s;

        list_for_each_entry(s, &d->streams, list) {
                unsigned int j = msecs_to_jiffies(timeout_ms);

                if (wait_event_interruptible_timeout(s->ready_wait, s->ready_processing, j) <= 0)
                        return false;
        }

        return true;
}

#endif