//
// Author: Wolfgang Spraul
//
// This is free and unencumbered software released into the public domain.
// For details see the UNLICENSE file at the root of the source tree.
//

int fpga_find_iob(struct fpga_model* model, const char* sitename,
	int* y, int* x, dev_type_idx_t* idx);

const char* fpga_iob_sitename(struct fpga_model* model, int y, int x,
	dev_type_idx_t idx);

//
// When dealing with devices, there are two indices:
// 1. The index of the device in the device array for that tile.
// 2. The index of the device within devices of the same type in the tile.
//

// Looks up a device index based on the type index.
dev_idx_t fpga_dev_idx(struct fpga_model* model,
	int y, int x, enum fpgadev_type type, dev_type_idx_t type_idx);

// Counts how many devices of the same type as dev_idx are in
// the array up to dev_idx.
dev_type_idx_t fpga_dev_typeidx(struct fpga_model* model, int y, int x,
	dev_idx_t dev_idx);

enum { A6_LUT, B6_LUT, C6_LUT, D6_LUT };
// lut_len can be -1 (ZTERM)
int fpga_set_lut(struct fpga_model* model, struct fpga_device* dev,
	int which_lut, const char* lut_str, int lut_len);

// Returns the connpt index or NO_CONN if the name was not
// found. connpt_dests_o and num_dests are optional and may
// return the offset into the connpt's destination array
// and number of elements there.
int fpga_connpt_find(struct fpga_model* model, int y, int x,
	str16_t name_i, int* connpt_dests_o, int* num_dests);

void fpga_conn_dest(struct fpga_model* model, int y, int x,
	int connpt_dest_idx, int* dest_y, int* dest_x, str16_t* str_i);

//
// switches
//

typedef int swidx_t; // swidx_t is an index into the uint32_t switches array
#define MAX_SW_DEPTH 64 // largest seen so far was 20

struct sw_set
{
	swidx_t sw[MAX_SW_DEPTH];
	int len;
};

// returns a switch index, or -1 (NO_SWITCH) if no switch was found
swidx_t fpga_switch_first(struct fpga_model* model, int y, int x,
	str16_t name_i, int from_to);
swidx_t fpga_switch_next(struct fpga_model* model, int y, int x,
	swidx_t last, int from_to);
swidx_t fpga_switch_backtofirst(struct fpga_model* model, int y, int x,
	swidx_t last, int from_to);
swidx_t fpga_switch_lookup(struct fpga_model* model, int y, int x,
	str16_t from_str_i, str16_t to_str_i);

const char* fpga_switch_str(struct fpga_model* model, int y, int x,
	swidx_t swidx, int from_to);
str16_t fpga_switch_str_i(struct fpga_model* model, int y, int x,
	swidx_t swidx, int from_to);
int fpga_switch_is_bidir(struct fpga_model* model, int y, int x,
	swidx_t swidx);
int fpga_switch_is_used(struct fpga_model* model, int y, int x,
	swidx_t swidx);
void fpga_switch_enable(struct fpga_model* model, int y, int x,
	swidx_t swidx);
int fpga_switch_set_enable(struct fpga_model* model, int y, int x,
	struct sw_set* set);
void fpga_switch_disable(struct fpga_model* model, int y, int x,
	swidx_t swidx);

const char* fmt_sw(struct fpga_model* model, int y, int x,
	swidx_t sw, int from_to);
const char* fmt_swset(struct fpga_model* model, int y, int x,
	struct sw_set* set, int from_to);

struct sw_chain
{
	// start and recurring values:
	struct fpga_model* model;
	int y;
	int x;
	// start_switch will be set to STRIDX_NO_ENTRY (0) after the first call
	str16_t start_switch;
	int from_to;
	int max_chain_size;

	// return values:
	struct sw_set set;

	// internal:
	int first_round;	
};

// Returns 0 if another switchset is returned in chain, or
// NO_SWITCH (-1) if there is no other switchset.
// chain_size set to 0 when there are no more switches in the tree
int fpga_switch_chain(struct sw_chain* chain);

// returns error code or 0 for no errors
int fpga_switch_chains(struct sw_chain* chain, int max_sets,
	struct sw_set* sets, int* num_sets);

struct sw_conns
{
	// start and recurring values:
   	struct fpga_model* model;
	int y;
	int x;
	// start_switch will be set to STRIDX_NO_ENTRY (0) after first call
	str16_t start_switch;
	int max_switch_depth;

	// return values:
	struct sw_chain chain;
	int connpt_dest_start;
	int num_dests;
	int dest_i;
	int dest_y;
	int dest_x;
	str16_t dest_str_i;
};

// Returns 0 if another connection is returned in conns, or
// NO_CONN (-1) if there is no other connection.
int fpga_switch_conns(struct sw_conns* conns);

void printf_swchain(struct fpga_model* model, int y, int x,
	str16_t sw, int max_depth, int from_to);
void printf_swconns(struct fpga_model* model, int y, int x,
	str16_t sw, int max_depth);

#define SWTO_YX_DEF			0
#define SWTO_YX_CLOSEST			0x0001
#define SWTO_YX_TARGET_CONNPT		0x0002
#define SWTO_YX_MAX_SWITCH_DEPTH	0x0004

struct switch_to_yx
{
	// input:
	int yx_req; // YX_-value
	int flags; // SWTO_YX-value
	struct fpga_model* model;
	int y;
	int x;
	str16_t start_switch;
	int max_switch_depth; // only if SWTO_YX_MAX_SWITCH_DEPTH is set
	str16_t target_connpt; // only if SWTO_YX_TARGET_CONNPT is set

	// output:
	struct sw_set set;
	int dest_y;
	int dest_x;
	str16_t dest_connpt;
};

int fpga_switch_to_yx(struct switch_to_yx* p);

//
// nets
//

// The last m1 soc has about 20k nets with about 470k
// connection points. The largest net has about 110
// connection points. For now we work with a simple
// fixed-size array, we can later make this more dynamic
// depending on which load on the memory manager is better.
#define MAX_NET_LEN	128

#define NET_IDX_IS_PINW	0x8000
#define NET_IDX_MASK	0x7FFF

struct net_el
{
	uint16_t y;
	uint16_t x;
	// idx is either an index into tile->switches[]
	// if bit15 (NET_IDX_IS_PINW) is off, or an index
	// into dev->pinw[] if bit15 is on.
	uint16_t idx;
	uint16_t dev_idx; // only used if idx&NET_IDX_IS_PINW
};

struct fpga_net
{
	int len;
	struct net_el el[MAX_NET_LEN];
};

typedef int net_idx_t; // net indices are 1-based
#define NO_NET 0

int fpga_net_new(struct fpga_model* model, net_idx_t* new_idx);
// start a new enumeration by calling with last==NO_NET
int fpga_net_enum(struct fpga_model* model, net_idx_t last, net_idx_t* next);
struct fpga_net* fpga_net_get(struct fpga_model* model, net_idx_t net_i);
int fpga_net_add_port(struct fpga_model* model, net_idx_t net_i,
	int y, int x, dev_idx_t dev_idx, pinw_idx_t pinw_idx);
int fpga_net_add_switches(struct fpga_model* model, net_idx_t net_i,
	int y, int x, const struct sw_set* set);
void fpga_net_free_all(struct fpga_model* model);