275 lines
8.0 KiB
Plaintext
275 lines
8.0 KiB
Plaintext
#include <xs1.h>
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#include <xclib.h>
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#include <print.h>
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#include "usb_midi.h"
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#include "midiinparse.h"
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#include "midioutparse.h"
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#include "queue.h"
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//#define MIDI_LOOPBACK 1
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static unsigned makeSymbol(unsigned data) {
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// Start and stop bits to the data packet
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// like 10'b1dddddddd0
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return (data << 1) | 0x200;
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}
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#define RATE 31250
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static unsigned bit_time = XS1_TIMER_MHZ * 1000000 / (unsigned) RATE;
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static unsigned bit_time_2 = (XS1_TIMER_MHZ * 1000000 / (unsigned) RATE) / 2;
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// For debugging
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int mr_count = 0; // MIDI received (from HOST)
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int th_count = 0; // MIDI sent (To Host)
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#ifdef MIDI_LOOPBACK
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static inline void handle_byte_from_uart(chanend c_midi, struct midi_in_parse_state &mips, int cable_number,
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int &got_next_event, int &next_event, int &waiting_for_ack, int byte)
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{
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int valid;
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unsigned event;
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{valid, event} = midi_in_parse(mips, cable_number, byte);
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if (valid && !got_next_event) {
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// data to send to host
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if (!waiting_for_ack) {
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// send data
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event = byterev(event);
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outuint(c_midi, event);
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th_count++;
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waiting_for_ack = 1;
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}
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else {
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event = byterev(event);
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next_event = event;
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got_next_event = 1;
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}
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}
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else if (valid) {
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// printstr("g\n");
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}
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}
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#endif
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int uout_count = 0; // UART bytes out
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int uin_count = 0; // UART bytes in
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void usb_midi(in port ?p_midi_in, out port ?p_midi_out,
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clock ?clk_midi,
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chanend c_midi,
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unsigned cable_number) {
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unsigned symbol = 0x0; // Symbol in progress of being sent out
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unsigned outputting = 0; // Guard when outputting data
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unsigned txT; // Timer value used for outputting
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//unsigned inputPortState, newInputPortState;
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int waiting_for_ack = 0;
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// Receiver
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unsigned rxByte;
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int rxI;
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int rxT;
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int isRX = 0;
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timer t;
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timer t2;
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// One place buffer for data going out to host
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queue to_host_fifo;
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unsigned to_host_fifo_arr[1];
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unsigned outputting_symbol, outputted_symbol;
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struct midi_in_parse_state mips;
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// the symbol fifo (to go out of uart)
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queue symbol_fifo;
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unsigned symbol_fifo_arr[USB_MIDI_DEVICE_OUT_FIFO_SIZE];
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unsigned rxPT, txPT;
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int midi_from_host_overflow = 0;
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//configure_clock_rate(clk_midi, 100, 1);
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init_queue(symbol_fifo, symbol_fifo_arr, USB_MIDI_DEVICE_OUT_FIFO_SIZE);
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init_queue(to_host_fifo, to_host_fifo_arr, 1);
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configure_out_port_no_ready(p_midi_out, clk_midi, 1);
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configure_in_port(p_midi_in, clk_midi);
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start_clock(clk_midi);
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start_port(p_midi_out);
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start_port(p_midi_in);
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reset_midi_state(mips);
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t :> txT;
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t2 :> rxT;
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#ifndef MIDI_LOOPBACK
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p_midi_out <: 1; // Start with high bit.
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// printstr("mout0");
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#endif
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while (1) {
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int is_ack;
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unsigned int datum;
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select {
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// Input to read the start bit
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#ifndef MIDI_LOOPBACK
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#ifdef MIDI_IN_4BIT_PORT
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case !isRX => p_midi_in when pinseq(0xE) :> void @ rxPT:
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#else
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case !isRX => p_midi_in when pinseq(0) :> void @ rxPT:
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#endif
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isRX = 1;
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t2 :> rxT;
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rxT += (bit_time + bit_time_2);
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rxPT += (bit_time + bit_time_2); // absorb start bit and set to halfway through the next bit
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rxI = 0;
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asm("setc res[%0],1"::"r"(p_midi_in));
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asm("setpt res[%0],%1"::"r"(p_midi_in),"r"(rxPT));
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break;
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// Input to read the remaining bits
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case isRX => t2 when timerafter(rxT) :> int _ :
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if (rxI++ < 8) {
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// shift in bits into the high end of a word
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unsigned bit;
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p_midi_in :> bit;
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rxByte = (bit << 31) | (rxByte >> 1);
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rxT += bit_time;
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rxPT += bit_time;
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asm("setpt res[%0],%1"::"r"(p_midi_in),"r"(rxPT));
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} else {
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unsigned bit;
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// rcv and check stop bit
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p_midi_in :> bit;
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if ((bit & 0x1) == 1) {
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unsigned valid = 0;
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unsigned event = 0;
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uin_count++;
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rxByte >>= 24;
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// if (rxByte != outputted_symbol) {
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// // Loopback check
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// printhexln(rxByte);
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// printhexln(outputted_symbol);
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// }
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{valid, event} = midi_in_parse(mips, cable_number, rxByte);
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if (valid && isempty(to_host_fifo)) {
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event = byterev(event);
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// data to send to host - add to fifo
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if (!waiting_for_ack) {
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// send data
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// printstr("uart->decouple: ");
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outuint(c_midi, event);
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waiting_for_ack = 1;
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th_count++;
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} else {
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enqueue(to_host_fifo, event);
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}
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} else if (valid) {
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// printstr("g");
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}
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}
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isRX = 0;
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}
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break;
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// Output
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// If outputting then feed the bits out one at a time
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// until symbol is zero expect pattern like 10'b1dddddddd0
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// This code will leave the output high afterwards due to the stop bit added with makeSymbol
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case outputting => t when timerafter(txT) :> int _:
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if (symbol == 0) {
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// Start sending symbol.
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// This case is reached when a symbol has been received from the host but not started AND
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// When it has just finished sending a symbol
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// have we got another symbol to send to uart?
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if (!isempty(symbol_fifo)) { // FIFO not empty
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// Take from FIFO
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outputting_symbol = dequeue(symbol_fifo);
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symbol = makeSymbol(outputting_symbol);
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if (space(symbol_fifo) > 3 && midi_from_host_overflow) {
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midi_from_host_overflow = 0;
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midi_send_ack(c_midi);
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}
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p_midi_out <: 1 @ txPT;
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// printstr("mout1\n");
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t :> txT;
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txT += bit_time;
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txPT += bit_time;
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// leave outputting set
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} else
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outputting = 0;
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} else {
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txT += bit_time;
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txPT += bit_time;
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p_midi_out @ txPT <: (symbol & 1);
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// printstr("mout2\n");
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symbol >>= 1;
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if (symbol == 0) {
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// Finished sending
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uout_count++;
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outputted_symbol = outputting_symbol;
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}
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}
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break;
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#endif
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case midi_get_ack_or_data(c_midi, is_ack, datum):
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if (is_ack) {
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// have we got more data to send
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//printstr("ack\n");
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if (!isempty(to_host_fifo)) {
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//printstr("uart->decouple\n");
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outuint(c_midi, dequeue(to_host_fifo));
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th_count++;
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} else {
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waiting_for_ack = 0;
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}
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} else {
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int event;
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unsigned midi[3];
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unsigned size;
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// received data from host
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event = byterev(datum);
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mr_count++;
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#ifdef MIDI_LOOPBACK
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if (isempty(to_host_fifo)) {
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// data to send to host
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if (!waiting_for_ack) {
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// send data
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event = byterev(event);
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outuint(c_midi, event);
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th_count++;
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waiting_for_ack = 1;
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} else {
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event = byterev(event);
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enqueue(to_host_fifo, event);
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}
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}
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#else
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{midi[0], midi[1], midi[2], size} = midi_out_parse(event);
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for (int i = 0; i != size; i++) {
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// add symbol to fifo
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enqueue(symbol_fifo, midi[i]);
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}
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if (space(symbol_fifo) > 3) {
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midi_send_ack(c_midi);
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} else {
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midi_from_host_overflow = 1;
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}
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// Could this drop through to the outputting case instead......
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if (!outputting) {
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t :> txT; // Should be enough to trigger the other case
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outputting = 1;
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}
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#endif
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}
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break;
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}
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}
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}
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