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Diffstat (limited to 'circuitpython/lib/adafruit_floppy/src/Adafruit_Floppy.cpp')
-rw-r--r--circuitpython/lib/adafruit_floppy/src/Adafruit_Floppy.cpp524
1 files changed, 524 insertions, 0 deletions
diff --git a/circuitpython/lib/adafruit_floppy/src/Adafruit_Floppy.cpp b/circuitpython/lib/adafruit_floppy/src/Adafruit_Floppy.cpp
new file mode 100644
index 0000000..eef1aa0
--- /dev/null
+++ b/circuitpython/lib/adafruit_floppy/src/Adafruit_Floppy.cpp
@@ -0,0 +1,524 @@
+#include "Adafruit_Floppy.h"
+
+#define DEBUG_FLOPPY (0)
+
+// We need to read and write some pins at optimized speeds - use raw registers
+// or native SDK API!
+#ifdef BUSIO_USE_FAST_PINIO
+#define read_index() (*indexPort & indexMask)
+#define read_data() (*dataPort & dataMask)
+#define set_debug_led() (*ledPort |= ledMask)
+#define clr_debug_led() (*ledPort &= ~ledMask)
+#elif defined(ARDUINO_ARCH_RP2040)
+#define read_index() gpio_get(_indexpin)
+#define read_data() gpio_get(_rddatapin)
+#define set_debug_led() gpio_put(led_pin, 1)
+#define clr_debug_led() gpio_put(led_pin, 0)
+#endif
+
+uint32_t T2_5 = T2_5_IBMPC_HD;
+uint32_t T3_5 = T3_5_IBMPC_HD;
+
+#if !DEBUG_FLOPPY
+#undef set_debug_led
+#undef clr_debug_led
+#define set_debug_led() ((void)0)
+#define clr_debug_led() ((void)0)
+#endif
+
+#define MFM_IO_MMIO (1)
+#include "mfm_impl.h"
+
+/**************************************************************************/
+/*!
+ @brief Create a hardware interface to a floppy drive
+ @param densitypin A pin connected to the floppy Density Select input
+ @param indexpin A pin connected to the floppy Index Sensor output
+ @param selectpin A pin connected to the floppy Drive Select input
+ @param motorpin A pin connected to the floppy Motor Enable input
+ @param directionpin A pin connected to the floppy Stepper Direction input
+ @param steppin A pin connected to the floppy Stepper input
+ @param wrdatapin A pin connected to the floppy Write Data input
+ @param wrgatepin A pin connected to the floppy Write Gate input
+ @param track0pin A pin connected to the floppy Track 00 Sensor output
+ @param protectpin A pin connected to the floppy Write Protect Sensor output
+ @param rddatapin A pin connected to the floppy Read Data output
+ @param sidepin A pin connected to the floppy Side Select input
+ @param readypin A pin connected to the floppy Ready/Disk Change output
+
+*/
+/**************************************************************************/
+
+Adafruit_Floppy::Adafruit_Floppy(int8_t densitypin, int8_t indexpin,
+ int8_t selectpin, int8_t motorpin,
+ int8_t directionpin, int8_t steppin,
+ int8_t wrdatapin, int8_t wrgatepin,
+ int8_t track0pin, int8_t protectpin,
+ int8_t rddatapin, int8_t sidepin,
+ int8_t readypin) {
+ _densitypin = densitypin;
+ _indexpin = indexpin;
+ _selectpin = selectpin;
+ _motorpin = motorpin;
+ _directionpin = directionpin;
+ _steppin = steppin;
+ _wrdatapin = wrdatapin;
+ _wrgatepin = wrgatepin;
+ _track0pin = track0pin;
+ _protectpin = protectpin;
+ _rddatapin = rddatapin;
+ _sidepin = sidepin;
+ _readypin = readypin;
+}
+
+/**************************************************************************/
+/*!
+ @brief Initializes the GPIO pins but do not start the motor or anything
+*/
+/**************************************************************************/
+void Adafruit_Floppy::begin(void) { soft_reset(); }
+
+/**************************************************************************/
+/*!
+ @brief Set back the object and pins to initial state
+*/
+/**************************************************************************/
+void Adafruit_Floppy::soft_reset(void) {
+ // deselect drive
+ pinMode(_selectpin, OUTPUT);
+ digitalWrite(_selectpin, HIGH);
+
+ // motor enable pin, drive low to turn on motor
+ pinMode(_motorpin, OUTPUT);
+ digitalWrite(_motorpin, HIGH);
+
+ // set motor direction (low is in, high is out)
+ pinMode(_directionpin, OUTPUT);
+ digitalWrite(_directionpin, LOW); // move inwards to start
+
+ // step track pin, pulse low for 3us min, 3ms max per pulse
+ pinMode(_steppin, OUTPUT);
+ digitalWrite(_steppin, HIGH);
+
+ // side selector
+ pinMode(_sidepin, OUTPUT);
+ digitalWrite(_sidepin, HIGH); // side 0 to start
+
+ pinMode(_indexpin, INPUT_PULLUP);
+ pinMode(_track0pin, INPUT_PULLUP);
+ pinMode(_protectpin, INPUT_PULLUP);
+ pinMode(_readypin, INPUT_PULLUP);
+ pinMode(_rddatapin, INPUT_PULLUP);
+
+ // set high density
+ pinMode(_densitypin, OUTPUT);
+ digitalWrite(_densitypin, LOW);
+
+ // set write OFF
+ if (_wrdatapin >= 0) {
+ pinMode(_wrdatapin, OUTPUT);
+ digitalWrite(_wrdatapin, HIGH);
+ }
+ if (_wrgatepin >= 0) {
+ pinMode(_wrgatepin, OUTPUT);
+ digitalWrite(_wrgatepin, HIGH);
+ }
+
+#ifdef BUSIO_USE_FAST_PINIO
+ indexPort = (BusIO_PortReg *)portInputRegister(digitalPinToPort(_indexpin));
+ indexMask = digitalPinToBitMask(_indexpin);
+#endif
+
+ select_delay_us = 10;
+ step_delay_us = 10000;
+ settle_delay_ms = 15;
+ motor_delay_ms = 1000;
+ watchdog_delay_ms = 1000;
+ bus_type = BUSTYPE_IBMPC;
+
+ if (led_pin >= 0) {
+ pinMode(led_pin, OUTPUT);
+ digitalWrite(led_pin, LOW);
+ }
+}
+
+/**************************************************************************/
+/*!
+ @brief Whether to select this drive
+ @param selected True to select/enable
+*/
+/**************************************************************************/
+void Adafruit_Floppy::select(bool selected) {
+ digitalWrite(_selectpin, !selected); // Selected logic level 0!
+ // Select drive
+ delayMicroseconds(select_delay_us);
+}
+
+/**************************************************************************/
+/*!
+ @brief Which head/side to read from
+ @param head Head 0 or 1
+*/
+/**************************************************************************/
+void Adafruit_Floppy::side(uint8_t head) {
+ digitalWrite(_sidepin, !head); // Head 0 is logic level 1, head 1 is logic 0!
+}
+
+/**************************************************************************/
+/*!
+ @brief Turn on or off the floppy motor, if on we wait till we get an index
+ pulse!
+ @param motor_on True to turn on motor, False to turn it off
+ @returns False if turning motor on and no index pulse found, true otherwise
+*/
+/**************************************************************************/
+bool Adafruit_Floppy::spin_motor(bool motor_on) {
+ digitalWrite(_motorpin, !motor_on); // Motor on is logic level 0!
+ if (!motor_on)
+ return true; // we're done, easy!
+
+ delay(motor_delay_ms); // Main motor turn on
+
+ uint32_t index_stamp = millis();
+ bool timedout = false;
+
+ if (debug_serial)
+ debug_serial->print("Waiting for index pulse...");
+
+ while (digitalRead(_indexpin)) {
+ if ((millis() - index_stamp) > 10000) {
+ timedout = true; // its been 10 seconds?
+ break;
+ }
+ }
+
+ if (timedout) {
+ if (debug_serial)
+ debug_serial->println("Didn't find an index pulse!");
+ return false;
+ }
+ if (debug_serial)
+ debug_serial->println("Found!");
+ return true;
+}
+
+/**************************************************************************/
+/*!
+ @brief Seek to the desired track, requires the motor to be spun up!
+ @param track_num The track to step to
+ @return True If we were able to get to the track location
+*/
+/**************************************************************************/
+bool Adafruit_Floppy::goto_track(uint8_t track_num) {
+ // track 0 is a very special case because its the only one we actually know we
+ // got to. if we dont know where we are, or we're going to track zero, step
+ // back till we get there.
+ if ((_track < 0) || track_num == 0) {
+ if (debug_serial)
+ debug_serial->println("Going to track 0");
+
+ // step back a lil more than expected just in case we really seeked out
+ uint8_t max_steps = 100;
+ while (max_steps--) {
+ if (!digitalRead(_track0pin)) {
+ _track = 0;
+ break;
+ }
+ step(STEP_OUT, 1);
+ }
+
+ if (digitalRead(_track0pin)) {
+ // we never got a track 0 indicator :(
+ // what if we try stepping in a bit??
+
+ max_steps = 20;
+ while (max_steps--) {
+ if (!digitalRead(_track0pin)) {
+ _track = 0;
+ break;
+ }
+ step(STEP_IN, 1);
+ }
+
+ if (digitalRead(_track0pin)) {
+ // STILL not found!
+ if (debug_serial)
+ debug_serial->println("Could not find track 0");
+ return false; // we 'timed' out, were not able to locate track 0
+ }
+ }
+ }
+ delay(settle_delay_ms);
+
+ // ok its a non-track 0 step, first, we cant go past 79 ok?
+ track_num = min(track_num, FLOPPY_IBMPC_HD_TRACKS - 1);
+ if (debug_serial)
+ debug_serial->printf("Going to track %d\n\r", track_num);
+
+ if (_track == track_num) { // we are there already
+ return true;
+ }
+
+ int8_t steps = (int8_t)track_num - (int8_t)_track;
+ if (steps > 0) {
+ if (debug_serial)
+ debug_serial->printf("Step in %d times\n\r", steps);
+ step(STEP_IN, steps);
+ } else {
+ steps = abs(steps);
+ if (debug_serial)
+ debug_serial->printf("Step out %d times\n\r", steps);
+ step(STEP_OUT, steps);
+ }
+ delay(settle_delay_ms);
+ _track = track_num;
+
+ return true;
+}
+
+/**************************************************************************/
+/*!
+ @brief Step the track motor
+ @param dir STEP_OUT or STEP_IN depending on desired direction
+ @param times How many steps to take
+*/
+/**************************************************************************/
+void Adafruit_Floppy::step(bool dir, uint8_t times) {
+ digitalWrite(_directionpin, dir);
+ delayMicroseconds(10); // 1 microsecond, but we're generous
+
+ while (times--) {
+ digitalWrite(_steppin, HIGH);
+ delay((step_delay_us / 1000UL) + 1); // round up to at least 1ms
+ digitalWrite(_steppin, LOW);
+ delay((step_delay_us / 1000UL) + 1);
+ digitalWrite(_steppin, HIGH); // end high
+ yield();
+ }
+ // one more for good measure (5.25" drives seemed to like this)
+ delay((step_delay_us / 1000UL) + 1);
+}
+
+/**************************************************************************/
+/*!
+ @brief The current track location, based on internal caching
+ @return The cached track location
+*/
+/**************************************************************************/
+int8_t Adafruit_Floppy::track(void) { return _track; }
+
+/**************************************************************************/
+/*!
+ @brief Capture and decode one track of MFM data
+ @param sectors A pointer to an array of memory we can use to store into,
+ 512*n_sectors bytes
+ @param n_sectors The number of sectors (e.g., 18 for a
+ standard 3.5", 1.44MB format)
+ @param sector_validity An array of values set to 1 if the sector was
+ captured, 0 if not captured (no IDAM, CRC error, etc)
+ @return Number of sectors we actually captured
+*/
+/**************************************************************************/
+uint32_t Adafruit_Floppy::read_track_mfm(uint8_t *sectors, size_t n_sectors,
+ uint8_t *sector_validity) {
+ mfm_io_t io;
+#ifdef BUSIO_USE_FAST_PINIO
+ BusIO_PortReg *dataPort, *ledPort;
+ BusIO_PortMask dataMask, ledMask;
+ dataPort = (BusIO_PortReg *)portInputRegister(digitalPinToPort(_rddatapin));
+ dataMask = digitalPinToBitMask(_rddatapin);
+ ledPort = (BusIO_PortReg *)portOutputRegister(digitalPinToPort(led_pin));
+ ledMask = digitalPinToBitMask(led_pin);
+ (void)ledPort;
+ (void)ledMask;
+ io.index_port = indexPort;
+ io.index_mask = indexMask;
+ io.data_port = dataPort;
+ io.data_mask = dataMask;
+#elif defined(ARDUINO_ARCH_RP2040)
+ io.index_port = &sio_hw->gpio_in;
+ io.index_mask = 1u << _indexpin;
+ io.data_port = &sio_hw->gpio_in;
+ io.data_mask = 1u << _rddatapin;
+#endif
+
+ noInterrupts();
+ int result = read_track(io, n_sectors, sectors, sector_validity);
+ interrupts();
+
+ return result;
+}
+
+/**************************************************************************/
+/*!
+ @brief Capture one track's worth of flux transitions, between two falling
+ index pulses
+ @param pulses A pointer to an array of memory we can use to store into
+ @param max_pulses The size of the allocated pulses array
+ @return Number of pulses we actually captured
+*/
+/**************************************************************************/
+uint32_t Adafruit_Floppy::capture_track(uint8_t *pulses, uint32_t max_pulses) {
+ unsigned pulse_count;
+ uint8_t *pulses_ptr = pulses;
+ uint8_t *pulses_end = pulses + max_pulses;
+
+#ifdef BUSIO_USE_FAST_PINIO
+ BusIO_PortReg *dataPort, *ledPort;
+ BusIO_PortMask dataMask, ledMask;
+ dataPort = (BusIO_PortReg *)portInputRegister(digitalPinToPort(_rddatapin));
+ dataMask = digitalPinToBitMask(_rddatapin);
+ ledPort = (BusIO_PortReg *)portOutputRegister(digitalPinToPort(led_pin));
+ ledMask = digitalPinToBitMask(led_pin);
+ (void)ledPort;
+ (void)ledMask;
+#endif
+
+ memset(pulses, 0, max_pulses); // zero zem out
+
+ noInterrupts();
+ wait_for_index_pulse_low();
+
+ // wait for one clean flux pulse so we dont get cut off.
+ // don't worry about losing this pulse, we'll get it on our
+ // overlap run!
+
+ // ok we have a h-to-l transition so...
+ bool last_index_state = read_index();
+ uint8_t index_transitions = 0;
+
+ // if data line is low, wait till it rises
+ if (!read_data()) {
+ while (!read_data())
+ ;
+ }
+ // if data line is high, wait till it drops down
+ if (read_data()) {
+ while (read_data())
+ ;
+ }
+
+ while (true) {
+ bool index_state = read_index();
+ // ahh a L to H transition
+ if (!last_index_state && index_state) {
+ index_transitions++;
+ if (index_transitions ==
+ 2) // and its the second one, so we're done with this track!
+ break;
+ }
+ last_index_state = index_state;
+
+ // muahaha, now we can read track data!
+ // Don't start counting at zero because we lost some time checking for
+ // index. Empirically, at 180MHz and -O3 on M4, this gives the most 'even'
+ // timings, moving the bins from 41/63/83 to 44/66/89
+ pulse_count = 3;
+
+ // while pulse is in the low pulse, count up
+ while (!read_data()) {
+ pulse_count++;
+ }
+ set_debug_led();
+
+ // while pulse is high, keep counting up
+ while (read_data())
+ pulse_count++;
+ clr_debug_led();
+
+ pulses_ptr[0] = min(255u, pulse_count);
+ pulses_ptr++;
+ if (pulses_ptr == pulses_end) {
+ break;
+ }
+ }
+ // whew done
+ interrupts();
+ return pulses_ptr - pulses;
+}
+
+/**************************************************************************/
+/*!
+ @brief Busy wait until the index line goes from high to low
+*/
+/**************************************************************************/
+void Adafruit_Floppy::wait_for_index_pulse_low(void) {
+ // initial state
+ bool index_state = read_index();
+ bool last_index_state = index_state;
+
+ // wait until last index state is H and current state is L
+ while (true) {
+ index_state = read_index();
+ if (last_index_state && !index_state) {
+ return;
+ }
+ last_index_state = index_state;
+ }
+}
+
+/**************************************************************************/
+/*!
+ @brief Pretty print the counts in a list of flux transitions
+ @param pulses A pointer to an array of memory containing pulse counts
+ @param num_pulses The size of the pulses in the array
+*/
+/**************************************************************************/
+void Adafruit_Floppy::print_pulses(uint8_t *pulses, uint32_t num_pulses) {
+ if (!debug_serial)
+ return;
+
+ for (uint32_t i = 0; i < num_pulses; i++) {
+ debug_serial->print(pulses[i]);
+ debug_serial->print(", ");
+ }
+ debug_serial->println();
+}
+/**************************************************************************/
+/*!
+ @brief Pretty print a simple histogram of flux transitions
+ @param pulses A pointer to an array of memory containing pulse counts
+ @param num_pulses The size of the pulses in the array
+ @param max_bins The maximum number of histogram bins to use (default 64)
+*/
+/**************************************************************************/
+void Adafruit_Floppy::print_pulse_bins(uint8_t *pulses, uint32_t num_pulses,
+ uint8_t max_bins) {
+ if (!debug_serial)
+ return;
+
+ // lets bin em!
+ uint32_t bins[max_bins][2];
+ memset(bins, 0, max_bins * 2 * sizeof(uint32_t));
+ // we'll add each pulse to a bin so we can figure out the 3 buckets
+ for (uint32_t i = 0; i < num_pulses; i++) {
+ uint8_t p = pulses[i];
+ // find a bin for this pulse
+ uint8_t bin = 0;
+ for (bin = 0; bin < max_bins; bin++) {
+ // bin already exists? increment the count!
+ if (bins[bin][0] == p) {
+ bins[bin][1]++;
+ break;
+ }
+ if (bins[bin][0] == 0) {
+ // ok we never found the bin, so lets make it this one!
+ bins[bin][0] = p;
+ bins[bin][1] = 1;
+ break;
+ }
+ }
+ if (bin == max_bins)
+ debug_serial->println("oof we ran out of bins but we'll keep going");
+ }
+ // this is a very lazy way to print the bins sorted
+ for (uint8_t pulse_w = 1; pulse_w < 255; pulse_w++) {
+ for (uint8_t b = 0; b < max_bins; b++) {
+ if (bins[b][0] == pulse_w) {
+ debug_serial->print(bins[b][0]);
+ debug_serial->print(": ");
+ debug_serial->println(bins[b][1]);
+ }
+ }
+ }
+}
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