/* libhw/w5500.h - <libhw/generic/net.h> implementation for the WIZnet W5500 chip
 *
 * Copyright (C) 2024-2025  Luke T. Shumaker <lukeshu@lukeshu.com>
 * SPDX-License-Identifier: AGPL-3.0-or-later
 */

#ifndef _LIBHW_W5500_H_
#define _LIBHW_W5500_H_

#include <pico/binary_info.h> /* for bi_* */

#include <libcr_ipc/chan.h>
#include <libcr_ipc/mutex.h>
#include <libcr_ipc/sema.h>
#include <libmisc/private.h>

#include <libhw/generic/net.h>
#include <libhw/generic/spi.h>

CR_CHAN_DECLARE(_w5500_sockintr_ch, uint8_t)

struct _w5500_socket {
	BEGIN_PRIVATE(LIBHW_W5500_H);
	/* const-after-init */
	uint8_t                          socknum;

	/* mutable */
	struct _w5500_socket            *next_free;
	enum {
		W5500_MODE_NONE = 0,
		W5500_MODE_TCP,
		W5500_MODE_UDP,
	}                                mode;
	uint16_t                         port;                             /* MODE_{TCP,UDP} */
	uint64_t                         read_deadline_ns;                 /* MODE_{TCP,UDP} */
	cr_sema_t                        listen_sema;                      /* MODE_TCP */
	cr_sema_t                        read_sema;                        /* MODE_{TCP,UDP} */
	_w5500_sockintr_ch_t             write_ch;                         /* MODE_{TCP,UDP} */
	bool                             list_open, read_open, write_open; /* MODE_TCP */

	END_PRIVATE(LIBHW_W5500_H);
};

LO_IMPLEMENTATION_H(io_closer, struct _w5500_socket, w5500_tcplist);
LO_IMPLEMENTATION_H(net_stream_listener, struct _w5500_socket, w5500_tcplist);

LO_IMPLEMENTATION_H(io_reader, struct _w5500_socket, w5500_tcp);
LO_IMPLEMENTATION_H(io_writer, struct _w5500_socket, w5500_tcp);
LO_IMPLEMENTATION_H(io_readwriter, struct _w5500_socket, w5500_tcp);
LO_IMPLEMENTATION_H(io_closer, struct _w5500_socket, w5500_tcp);
LO_IMPLEMENTATION_H(io_bidi_closer, struct _w5500_socket, w5500_tcp);
LO_IMPLEMENTATION_H(net_stream_conn, struct _w5500_socket, w5500_tcp);

LO_IMPLEMENTATION_H(io_closer, struct _w5500_socket, w5500_udp);
LO_IMPLEMENTATION_H(net_packet_conn, struct _w5500_socket, w5500_udp);

struct w5500 {
	BEGIN_PRIVATE(LIBHW_W5500_H);
	/* const-after-init */
	lo_interface spi                 spidev;
	uint                             pin_intr;
	uint                             pin_reset;
	struct net_eth_addr              hwaddr;

	/* mutable */
	uint16_t                         next_local_port;
	struct _w5500_socket             sockets[8];
	struct _w5500_socket            *free;
	cr_sema_t                        intr;
	cr_mutex_t                       mu;
	END_PRIVATE(LIBHW_W5500_H);
};
LO_IMPLEMENTATION_H(net_iface, struct w5500, w5500_if);

/**
 * Initialize a WIZnet W5500 Ethernet-and-TCP/IP-offload chip.
 *
 * The W5500 has 3 lines of communication with the MCU:
 *
 *  - An SPI-based RPC protocol:
 *    + mode: mode 0 or mode 3
 *    + bit-order: MSB-first
 *    + clock frequency: 33.3MHz - 80MHz
 *  - An interrupt pin that it pulls low when an event happens (to let
 *    the MCU know that it should do an SPI RPC "get" to see what
 *    happened.)
 *  - A reset pin that the MCU can pull low to reset the W5500.
 */
#define w5500_init(self, name, spi, pin_intr, pin_reset, eth_addr) do { \
		bi_decl(bi_2pins_with_names(pin_intr, name" interrupt", \
		                            pin_reset, name" reset"));  \
		_w5500_init(self, spi, pin_intr, pin_reset, eth_addr);  \
	} while (0)
void _w5500_init(struct w5500 *self,
                 lo_interface spi spi, uint pin_intr, uint pin_reset,
                 struct net_eth_addr addr);

/**
 * Perform a hard reset on the chip (pull the reset line low).
 *
 * If you have any in-use sockets when you call this, you're going to
 * have a bad time.
 */
void w5500_hard_reset(struct w5500 *self);

/**
 * Perform a soft reset on the chip (send the RST command).
 *
 * If you have any in-use sockets when you call this, you're going to
 * have a bad time.
 */
void w5500_soft_reset(struct w5500 *self);

#endif /* _LIBHW_W5500_H_ */