Files
lib_xua/module_usb_midi/src/usb_midi.xc

358 lines
12 KiB
Plaintext

#include <xs1.h>
#include <xclib.h>
#include <print.h>
#include <stdint.h>
#include "usb_midi.h"
#include "midiinparse.h"
#include "midioutparse.h"
#include "queue.h"
#ifdef IAP
#include "iap.h"
#include "iap_user.h"
#endif
//#define MIDI_LOOPBACK 1
int icount = 0;
static unsigned makeSymbol(unsigned data)
{
// Start and stop bits to the data packet
// like 10'b1dddddddd0
return (data << 1) | 0x200;
}
#define RATE 31250
#ifndef MIDI_SHIFT_TX
#define MIDI_SHIFT_TX 7
#endif
static unsigned bit_time = XS1_TIMER_MHZ * 1000000 / (unsigned) RATE;
static unsigned bit_time_2 = (XS1_TIMER_MHZ * 1000000 / (unsigned) RATE) / 2;
// For debugging
int mr_count = 0; // MIDI received (from HOST)
int th_count = 0; // MIDI sent (To Host)
int uout_count = 0; // UART bytes out
int uin_count = 0; // UART bytes in
// state for iAP
#ifdef IAP
extern unsigned authenticating;
#else
unsigned authenticating = 0;
#endif
// state for auto-selecting dock or USB B
extern unsigned polltime;
#ifdef IAP
timer iAPTimer;
#endif
void usb_midi(port ?p_midi_in, port ?p_midi_out,
clock ?clk_midi,
chanend ?c_midi,
unsigned cable_number,
chanend ?c_iap, chanend ?c_i2c, // iOS stuff
port ?p_scl, port ?p_sda
)
{
unsigned symbol = 0x0; // Symbol in progress of being sent out
unsigned isTX = 0; // Guard when outputting data
unsigned txT; // Timer value used for outputting
//unsigned inputPortState, newInputPortState;
int waiting_for_ack = 0;
// Receiver
unsigned rxByte;
int rxI;
int rxT;
int isRX = 0; // Guard when receiving data
timer t;
timer t2;
// One place buffer for data going out to host
queue midi_to_host_fifo;
unsigned char midi_to_host_fifo_arr[4]; // Used for 32bit USB MIDI events
unsigned outputting_symbol, outputted_symbol;
struct midi_in_parse_state mips;
// the symbol fifo (to go out of uart)
queue symbol_fifo;
unsigned char symbol_fifo_arr[USB_MIDI_DEVICE_OUT_FIFO_SIZE * 4]; // Used for 32bit USB MIDI events
unsigned rxPT, txPT;
int midi_from_host_overflow = 0;
//configure_clock_rate(clk_midi, 100, 1);
init_queue(symbol_fifo, symbol_fifo_arr, USB_MIDI_DEVICE_OUT_FIFO_SIZE, 4);
init_queue(midi_to_host_fifo, midi_to_host_fifo_arr, 1, 4);
configure_out_port(p_midi_out, clk_midi, 1<<MIDI_SHIFT_TX);
configure_in_port(p_midi_in, clk_midi);
/* Just in case not using CLKBLK_REF */
start_clock(clk_midi);
reset_midi_state(mips);
t :> txT;
t2 :> rxT;
#ifdef IAP
CoProcessorDisable();
#endif
// p_midi_out <: 1 << MIDI_SHIFT_TX; // Start with high bit.
#ifdef IAP
CoProcessorEnable();
#endif
#ifdef IAP
/* Check for special case where MIDI and i2c ports are shared... */
if(isnull(c_i2c) && isnull(p_scl) && isnull(p_sda))
{
init_iAP(c_i2c, p_midi_out, p_midi_in); // uses timer for i2c initialisation pause..
}
else
{
init_iAP(c_i2c, p_scl, p_sda); // uses timer for i2c initialisation pause..
}
#endif
{
#ifdef IAP
iAPTimer :> polltime;
polltime += XS1_TIMER_HZ / 2;
#endif
while (1)
{
int is_ack;
int is_reset;
unsigned int datum;
select
{
// Input to read the start bit
#ifndef MIDI_LOOPBACK
case (!authenticating && !isRX) => p_midi_in when pinseq(0) :> void @ rxPT:
isRX = 1;
t2 :> rxT;
rxT += (bit_time + bit_time_2);
rxPT += (bit_time + bit_time_2); // absorb start bit and set to halfway through the next bit
rxI = 0;
asm("setc res[%0],1"::"r"(p_midi_in));
asm("setpt res[%0],%1"::"r"(p_midi_in),"r"(rxPT));
break;
// Input to read the remaining bits
case (!authenticating && isRX) => t2 when timerafter(rxT) :> int _ :
{
unsigned bit;
p_midi_in :> bit;
if (rxI++ < 8)
{
// shift in bits into the high end of a word
rxByte = (bit << 31) | (rxByte >> 1);
rxT += bit_time;
rxPT += bit_time;
asm("setpt res[%0],%1"::"r"(p_midi_in),"r"(rxPT));
}
else
{
// rcv and check stop bit
if ((bit & 0x1) == 1)
{
unsigned valid = 0;
unsigned event = 0;
uin_count++;
rxByte >>= 24;
// if (rxByte != outputted_symbol) {
// // Loopback check
// printhexln(rxByte);
// printhexln(outputted_symbol);
// }
{valid, event} = midi_in_parse(mips, cable_number, rxByte);
if (valid && isempty(midi_to_host_fifo))
{
event = byterev(event);
// data to send to host - add to fifo
if (!waiting_for_ack)
{
// send data
// printstr("uart->decouple: ");
outuint(c_midi, event);
waiting_for_ack = 1;
th_count++;
}
else
{
enqueue(midi_to_host_fifo, event);
}
}
else if (valid)
{
//printstr("g");
}
}
isRX = 0;
}
break;
}
// Output
// If isTX then feed the bits out one at a time
// until symbol is zero expect pattern like 10'b1dddddddd0
// This code will leave the output high afterwards due to the stop bit added with makeSymbol
case (!authenticating && isTX) => t when timerafter(txT) :> int _:
if (symbol == 0)
{
// Got something to output but not mid-symbol.
// Start sending symbol.
// This case is reached when a symbol has been received from the host but not started AND
// When it has just finished sending a symbol
// Take from FIFO
outputting_symbol = dequeue(symbol_fifo);
symbol = makeSymbol(outputting_symbol);
if (space(symbol_fifo) > 3 && midi_from_host_overflow)
{
midi_from_host_overflow = 0;
midi_send_ack(c_midi);
}
p_midi_out <: (1<<MIDI_SHIFT_TX) @ txPT;
// printstr("mout1\n");
t :> txT;
txT += bit_time;
txPT += bit_time;
isTX = 1;
}
else
{
// Mid-symbol
txT += bit_time; // Should this be after the output otherwise be double the length of the high before the start bit
txPT += bit_time;
p_midi_out @ txPT <: ((symbol & 1)<<MIDI_SHIFT_TX);
// printstr("mout2\n");
symbol >>= 1;
if (symbol == 0)
{
// Finished sending byte
uout_count++;
outputted_symbol = outputting_symbol;
if (isempty(symbol_fifo))
{ // FIFO empty
isTX = 0;
}
}
}
break;
#endif
case !authenticating => midi_get_ack_or_data(c_midi, is_ack, datum):
if (is_ack)
{
// have we got more data to send
//printstr("ack\n");
if (!isempty(midi_to_host_fifo))
{
//printstr("uart->decouple\n");
outuint(c_midi, dequeue(midi_to_host_fifo));
th_count++;
}
else
{
waiting_for_ack = 0;
}
}
else
{
unsigned midi[3];
unsigned size;
// received data from host
int event = byterev(datum);
mr_count++;
#ifdef MIDI_LOOPBACK
if (isempty(midi_to_host_fifo))
{
// data to send to host
if (!waiting_for_ack)
{
// send data
event = byterev(event);
outuint(c_midi, event);
th_count++;
waiting_for_ack = 1;
}
else
{
event = byterev(event);
enqueue(midi_to_host_fifo, event);
}
midi_send_ack(c_midi);
}
else
{
//printstr("DROP\n");
}
#else
{midi[0], midi[1], midi[2], size} = midi_out_parse(event);
for (int i = 0; i != size; i++)
{
// add symbol to fifo
enqueue(symbol_fifo, midi[i]);
}
if (space(symbol_fifo) > 3)
{
midi_send_ack(c_midi);
}
else
{
midi_from_host_overflow = 1;
}
// Drop through to the isTX guarded case
if (!isTX)
{
t :> txT; // Should be enough to trigger the other case
isTX = 1;
}
#endif
}
break;
#ifdef IAP
case !(isTX || isRX) => iap_get_ack_or_reset_or_data(c_iap, is_ack, is_reset, datum):
/* Check for special case where MIDI ports are shared with i2c ports */
if(isnull(c_i2c) && isnull(p_scl) && isnull(p_sda))
{
handle_iap_case(is_ack, is_reset, datum, c_iap, c_i2c, p_midi_out, p_midi_in);
}
else
{
handle_iap_case(is_ack, is_reset, datum, c_iap, c_i2c, p_scl, p_sda);
}
if (!authenticating)
{
// printstrln("Completed authentication");
p_midi_in :> void; // Change port around to input again after authenticating (unique to midi+iAP case)
}
break;
/* Slow timer looking for IDevice plug/unplug event */
case iAPTimer when timerafter(polltime) :> void:
printintln(polltime);
handle_poll_dev_det(iAPTimer);
break;
#endif
}
}
}
}